ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (284)
  • wheat  (77)
  • Gas chromatography  (62)
  • TG  (56)
  • biological control  (43)
  • Pharmacokinetics
  • taxonomy
  • Springer  (284)
  • American Meteorological Society
  • 1995-1999  (284)
  • 1990-1994
  • 1985-1989
  • 1965-1969
  • 1955-1959
  • 1950-1954
  • 1999  (141)
  • 1998  (143)
  • Chemistry and Pharmacology  (161)
  • Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition  (122)
  • Computer Science  (1)
Collection
  • Articles  (284)
Keywords
Publisher
Years
  • 1995-1999  (284)
  • 1990-1994
  • 1985-1989
  • 1965-1969
  • 1955-1959
  • +
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Nutrient cycling in agroecosystems 53 (1999), S. 139-146 
    ISSN: 1573-0867
    Keywords: critical levels of Mn ; soil extractants ; Mn-deficiency ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Seven chemical extractants were tested for their relative performance to predict the response of wheat to Mn application in coarse textured alkaline soils of semi-arid region. Five out of the seven extractants were found to be promising for the estimation of critical level of available Mn in these soils, as the amount of Mn extracted by these extractants was positively and significantly correlated with relative grain yield as well as Mn uptake. The critical deficiency level of soil available Mn with 0.005 M DTPA, 0.02% hydroquinone, 0.02 N sodium pyrophosphate, 0.1N H3PO4 and 0.05N HCl+0.025N H2SO4 was 3.1, 13.8, 23.5, 5.3 and 17.8 mg kg-1 soil, respectively. The 1N ammonium acetate and 0.01M CaCl2 were found to be unsuitable extractants for these soils. Further field trials at eight locations with varying levels of Mn deficiency showed successive increase in the grain yield of wheat with foliar Mn application, emphasizing the need for Mn fertilization when wheat is grown on Mn deficient soils.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 3 (1998), S. 111-116 
    ISSN: 1572-9745
    Keywords: stored product mites ; biological control ; history ; predators ; prey
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A history of the biological control of stored product mites is reviewed. Thirty-five references in the scientific literature were found principally dealing with acarine predators. The first paper to point out the specific value of Cheyletus eruditus as a predator of acaroid mites appeared in 1912. In 1965 biological control utilizing C. eruditus was put into practice for the first time and in 1986 a method of mass rearing the predator was developed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 3 (1998), S. 63-83 
    ISSN: 1572-9745
    Keywords: Biosteres ; Coptera ; Diachasmimorpha ; Psyttalia ; Tetrastichus ; augmentation ; host habitat location ; dispersal ; behavioural ecology ; biological control ; classical biological control ; integrated pest management ; mass rearing ; quality control ; parasitoids ; tephritidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The biological control of pest tephritid flies using parasitoids has been successful in relatively few subtropical and tropical regions. The best documented successes were in Hawaii and Florida, USA, Fiji and southern Europe. There were relatively limited successes in Australia, Costa Rica and Mexico. With the accidental establishment of new pest tephritids, such as Bactrocera latifrons (Hendel) in Hawaii or Bactrocera papayae Drew and Hancock in Australia, foreign exploration for new parasitoids is essential. A renewal of interest in classical biological control has recently occurred, although not at the same level as in the 1940s and 1950s. New parasitoid species are currently being obtained for several tephritids, such as Ceratitis capitata (Weidemann), B. latifrons and Anastrepha suspensa (Loew). The advances in mass rearing and quality control technology for parasitoids has enabled researchers to perform large-scale field testing of these parasitoids to determine the potential of augmentative releases. Numerous studies on the augmentative release of parasitoids have been done. Historically, the larval—pupal parasitoid Diachasmimorpha longicaudata (Ashmead) has been the most frequently studied parasitoid, due to the ease of rearing this species. However, recent successes in rearing other species with different biologies, e.g. the egg—pupal parasitoid Biosteres arisanus (Sonan), the gregarious eulophid, Tetrastichus giffardianus (Silvestri) and the pupal parasitoid, Coptera sp., will enable researchers to broaden the repertoire of parasitoid species for the future. Both successes and failures in augmentative releases have occurred. Without knowledge of the behavioural ecology of parasitoids, the reasons for success or failure can only be surmised. Recent research on the dispersal and host habitat finding of tephritid parasitoids will provide insights into improving augmentation and conservation strategies. The integrated pest management (IPM) of tephritid flies in the tropics has been less well-developed than research and programmes for tephritids in temperate zones. Significant emphasis is now being placed on the development of quarantine treatment methods that are environmentally sound; thus IPM will take a larger role. Several existing pest management strategies are reviewed which show the potential for compatibility with the activities of tephritid parasitoids. These include trap cropping, insecticides with selective toxicity to the target pests, mass trapping with parapheromones, the sterile insect technique and field sanitation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 4 (1999), S. 127-143 
    ISSN: 1572-9745
    Keywords: wheat ; stored-grain ; integrated pest management ; aeration ; biological control ; grain sampling ; insect monitoring ; modeling ; area-wide IPM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Management of stored-grain insect pests by farmers or elevator managers should be based upon a knowledge of the grain storage environment and the ecology of insect pests. Grain storage facilities and practices, geographical location, government policies, and marketing demands for grain quality are discussed as factors influencing stored-grain insect pest management decisions in the United States. Typical practices include a small number of grain samples designed to provide grain quality information for segregation, blending and marketing. This low sampling rate results in subjective evaluation and inconsistent penalties for insect-related quality factors. Information on the efficacy of insect pest management practices in the United States, mainly for farm-stored wheat, is discussed, and stored-grain integrated pest management (IPM) is compared to field-crop IPM. The transition from traditional stored-grain insect pest control to IPM will require greater emphasis on sampling to estimate insect densities, the development of sound economic thresholds and decision-making strategies, more selective use of pesticides, and greater use of nonchemical methods such as aeration. New developments in insect monitoring, predictive computer models, grain cooling by aeration, biological control, and fumigation are reviewed, their potential for improving insect pest management is discussed, and future research needs are examined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 3 (1998), S. 225-242 
    ISSN: 1572-9745
    Keywords: Hypera postica ; alfalfa weevil ; Medicago sativa ; alfalfa ; biological control ; classical biological control
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Alfalfa weevil, Hypera postica (Gyllenhall) (Coleoptera: Curculionidae), is of Eurasian origin. This destructive pest of alfalfa (lucerne) was accidentally established in North America on three separate occasions. These introductions are commonly identified in the literature as biological strains: western alfalfa weevil, Egyptian alfalfa weevil (=Hypera brunneipennis Boheman), and eastern alfalfa weevil. Alfalfa weevil has been the target of classical biological control almost since its discovery in North America more than 90 years ago. These efforts have resulted in establishment of at least nine exotic parasitoids and egg predators: Bathyplectes curculionis (Thomson), B. anurus (Thomson) and B. stenostigma (Thomson) (Hymenoptera: Ichneumonidae); Microctonus aethiopoides Loan and M. colesi Drea (Hymenoptera: Braconidae), the latter of undetermined origin; Oomyzus incertus (Ratzenberg) (Hymenoptera: Eulophidae); Dibrachoides dynastes (Forester) and Peridesmia discus (Walker) (Hymenoptera: Pteromalidae); and Anaphes luna (Girault) (Hymenoptera: Mymaridae). A fungal pathogen, Zoophthora phytonomi Arthur (Phycomycetes: Entomophthoraceae), of undetermined origin, is becoming an increasingly important alfalfa weevil mortality factor. Most major USA alfalfa production areas now benefit from a complex of alfalfa weevil biological control agents. Collectively, these agents have effected substantial reduction in the economic importance of alfalfa weevil across the northern USA However, biological agents provide only partial control of alfalfa weevil, and importance of their contribution differs considerably with production area. Still, the benefits achieved, especially from reduced need for insecticides in alfalfa production, mark this as one of the great success stories of classical biological control in North America.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 4 (1999), S. 21-37 
    ISSN: 1572-9745
    Keywords: carrot weevil ; IPM ; Anaphes spp. ; biological control ; ecology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae) is a major pest of carrots in northeastern North America. The females oviposit in the leaf petiole and the developing larvae make tunnels in the carrot roots. Exclusive reliance on chemical control and the poor control obtained, prompted, in the early 1980s, research on the ecology and physiology of the pest and its natural enemies. Carrot weevil females start their oviposition by 147±9 DD7°C but they oviposit only in carrots past the 4 true-leaf-stage. As a result, oviposition is delayed, and damage reduced, in late-sown carrots. Monitoring carrot weevil adults in the spring with either carrot root sections or wooden plate traps enables growers to apply control treatments only if the population density justifies it. Egg parasitoids of the genus Anaphes (Hymenoptera: Mymaridae) are the most important natural enemies and they account, in untreated plots, for up to 80% mortality. Their effectiveness could be improved by managing field borders to establish secondary host species. An IPM programme was developed in the 1980s based on the research results obtained and, through regular monitoring, has achieved a substantial decrease in pesticide use.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 4 (1999), S. 39-52 
    ISSN: 1572-9745
    Keywords: Scapteriscus ; Neocurtilla ; Gryllotalpa ; biological control ; turf ; pastures ; vegetables
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract There are at least 70 species of mole crickets (Orthoptera: Gryllotalpidae). Some are rare, others are innocuous, and a few are important pests. These soil-dwelling pests damage underground parts of a long list of cultivated plants. Although tillage and flooding are used successfully in some situations to bring these pests to the soil surface and expose them to vertebrate and other predators, chemical pesticides are widely used against them. Knowledge of their life history is used to time application of chemical treatments to save money, but is not used as widely as it might be. Classical biological control has been used against immigrant mole crickets in Hawaii, Puerto Rico, and the southern USA. In Florida, three Scapteriscus species from South America cause major damage to pastures and turf and are targets of a classical biological control program. Population levels of two of the pest species have been reduced substantially in Florida by establishment of a tachinid fly (Ormia depleta) and a steinernematid nematode (Steinernema scapterisci) from South America. The nematode also functions as a biopesticide. Managers of pastures and turf in Florida have thus far derived benefit from these classical biological control agents without understanding their function: use of chemicals is reduced when mole cricket populations are lower due to action of these organisms. Future enhancement of the action of O. depleta and of a sphecid wasp (Larra bicolor, which also was introduced from South America) probably will demand deliberate planting of nectar sources for adults of these biological control agents, and the advantage will be to managers who adopt such a strategy. Chemical pesticide use is strongly promoted by a large chemical industry, whereas biopesticidal use has thus far been little promoted and sales have been few. Even managers who do not change their simple strategy of pesticide use in response to damage by mole crickets, and have no knowledge of the differing life cycles of the three Scapteriscus species or of the presence and action of the classical biological control agents, will derive benefit as these biological control agents (and a predatory beetle which has not yet been released) increase their distribution.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 4 (1999), S. 97-126 
    ISSN: 1572-9745
    Keywords: agriculture ; biological control ; campaign ; chemosterilent ; commensal ; control methods ; economics ; environmental and cultural methods ; horticulture ; India ; pest management ; pre- and post-harvest crop losses ; poultry farms ; rodent ; rodenticide ; South Asia ; trapping
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Eighteen species of rodents are pests in agriculture, horticulture, forestry, animal and human dwellings and rural and urban storage facilities in India. Their habitat, distribution, abundance and economic significance varies in different crops, seasons and geographical regions of the country. Of these, Bandicota bengalensis is the most predominant and widespread pest of agriculture in wet and irrigated soils and has also established in houses and godowns in metropolitan cities like Bombay, Delhi and Calcutta. In dryland agriculture Tatera indica and Meriones hurrianae are the predominant rodent pests. Some species like Rattus meltada, Mus musculus and M. booduga occur in both wet and dry lands. Species like R. nitidus in north-eastern hill region and Gerbillus gleadowi in the Indian desert are important locally. The common commensal pests are Rattus rattus and M. musculus throughout the country including the islands. R. rattus along with squirrels Funambulus palmarum and F. tristriatus are serious pests of plantation crops such as coconut and oil palm in the southern peninsula. F. pennanti is abundant in orchards and gardens in the north and central plains and sub-mountain regions. Analysis of the information available on the damage and economic losses caused by rodents in rice, wheat, sugarcane, maize, pearl millet, sorghum, oil seed, legume and vegetable crop fields, horticulture and forestry, poultry farms, and rural and urban dwellings and storage facilities clearly shows that chronic damage ranging from 2% to 15% persists throughout the country and severe damage, sometimes even up to 100% loss of the field crop, is not rare. Several traditional and modern approaches and methods of rodent control are being used. The existing knowledge of the environmental, cultural, biological, mechanical and chemical methods of rodent control in India is reviewed. Considerable variations exist in the susceptibility of the pest species to different methods, particularly to rodenticides and trapping, their field applicability, efficacy and economics in different crops, seasons and geographical regions, behavioural responses of the pest species to these methods in different ecological conditions and their adoption by farmers in different regions of India. Environmental and cultural techniques, such as clean cultivation, proper soil tillage and crop scheduling, barriers, repellents and proofing which may reduce rodent harbourage, food sources and immigration have long lasting effects but are seldom adopted. However, their significance in relation to normal agricultural practices, intensification and diversification are discussed. Rodenticides, which provide an immediate solution to the rodent problem, form the major component of rodent control strategies in India. Poison baiting of rodents with zinc phosphide and burrow fumigation with aluminium phosphide are common in agricultural fields and recently Racumin (coumatetralyl) and bromadiolone have been introduced for the control of both agricultural and commensal rodent pests in India. Methods and timings of campaigns and successes and problems in implementation of rodent control are also reviewed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Integrated pest management reviews 4 (1999), S. 307-312 
    ISSN: 1572-9745
    Keywords: microbial control ; biological control ; biopesticide ; mycopesticide ; Metarhizium ; Beauveria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Microbial control agents generally kill insects more slowly than chemical pesticides, and fast-moving migratory pests may not at first sight appear to offer the most promising targets for microbial control. Operators responsible for control may need to have recourse to chemical control agents. Nevertheless, there are many occasions when pests breed and feed outside the crop and a microbial control agent can be used. Similarly, immature stages may cause little damage and early treatment in the crop can avoid damage. Microbial control agents are particularly likely to be favoured if the pest breeds in a conservation area, and if a publicly-accountable agency is responsible for control. Other key points of importance are the IPM context, in particular detection, planning and forecasting of outbreaks and the role of natural enemies. With these points in mind, we identify several locust and grasshopper systems where microbial control is becoming established; additionally, Sunn pest of wheat and Armyworm are identified as promising situations forbreak microbials.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 53 (1998), S. 337-341 
    ISSN: 1432-1041
    Keywords: Key words Amikacin ; Neonate ; Pharmacokinetics ; NONMEM
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The population pharmacokinetics of amikacin, in neonates, was investigated using the nonlinear mixed effects model (NONMEM). Methods: One hundred and six steady-state amikacin serum levels were obtained from 53 black neonates with a mean gestational age of 35.1 weeks and mean age at the start of treatment of 3.1 days. A one-compartment model was used to fit the data. Results: The final models for clearance (CL) and volume of distribution (V) were: where WT = birth weight (kg) and P = 1.28 for girls and 1.0 for boys. Inclusion of other fixed effect parameters in the model did not significantly improve the fit of the data. The inter-individual variability for CL and V were 18% and 13%, respectively. Intra-individual variability was 29%. Mean (95% CI) values of CL, V and half-life were 0.048 (0.045, 0.051) l· h−1· kg−1, 0.434 (0.414, 0.453) l· kg−1 and 6.4 (6.2, 6.6) h respectively. Conclusion: Birth weight was an important determinant of both CL and V and, in this data set, gender was also found to influence CL. Mean population pharmacokinetic values were within the range of those previously derived for other neonatal populations using traditional methods.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 54 (1999), S. 847-849 
    ISSN: 1432-1041
    Keywords: Key words Sibutramine ; Pharmacokinetics ; Age
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: To investigate the pharmacokinetics of the pharmacologically active metabolites of sibutramine (metabolites 1 and 2) in healthy young and elderly volunteers following a single oral dose of sibutramine. Methods: This was an open, parallel-group study completed by 12 young (six male, six female; mean age 24.0 years) and 12 elderly (six male, six female; mean age 70.3 years) healthy volunteers. Blood samples were taken at intervals up to 48 h post-dose. Plasma concentrations of metabolites were determined using HPLC-MS. Model-independent pharmacokinetic parameters of the two metabolites were compared for the two age groups. Results: The similarity of the plasma profiles of the two desmethyl metabolites showed that despite the possibility of reduced hepatic function due to age, the rate and extent of formation of these was the same in both young and elderly, i.e. sibutramine metabolism was not impaired in elderly subjects. There were also no significant differences in elimination of metabolite 2 between groups, although the elderly group showed a slight trend for a reduction in kel. Conclusions: The pharmacokinetics of the two pharmacologically active metabolites of sibutramine (metabolites 1 and 2) were not significantly different between the young and elderly groups in this study. Based on this information, a similar dosing regimen would be appropriate for both the young and elderly.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 53 (1998), S. 375-376 
    ISSN: 1432-1041
    Keywords: Key words Artesunate ; Dihydroartemisinin ; Pharmacokinetics ; Bioequivalence
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 593-598 
    ISSN: 1432-1041
    Keywords: Key words Irbesartan ; Warfarin ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objectives: To determine whether the initiation or titration of irbesartan alters the pharmacodynamics and/or pharmacokinetics of warfarin in a clinically significant manner, thereby requiring additional monitoring of the anticoagulant effect of warfarin. Methods: Daily doses of warfarin were administered to 16 healthy males for 21 days (10 mg on day 1 and 2.5–10 mg on days 2–21). Irbesartan (300 mg/day) or placebo was concomitantly administered on days 15–21. The pharmacodynamic parameters prothrombin time (PT) and prothrombin time ratio (PTR) were evaluated throughout the study. Plasma and urine samples were collected before and up to 24 h after administration on days 14, 15 and 21 for the determination of the maximum concentration (Cmax), time to reach Cmax (tmax), the area under the concentration–time curve (AUC) of S-warfarin and the cumulative urinary excretion of warfarin and its metabolites. Pre-dose plasma samples were also collected to determine the Cmin of S-warfarin (days 12, 13, 14 and 21) and irbesartan (days 19, 20 and 21). Results: Analysis of PTR data revealed no significant difference between the group mean PTR values at day 22 and those at day 15 (P=0.699). S-warfarin concentrations in plasma and urine, as well as the urinary concentrations of the metabolites of warfarin, were not affected by concomitant single- or multiple-dose administration of irbesartan. Plasma Cmin concentrations of S-warfarin and irbesartan were also not affected. Conclusions: No clinically important effect of irbesartan on the pharmacodynamics and pharmacokinetics of warfarin are likely to occur during concomitant administration; therefore, neither a dosage adjustment of irbesartan or warfarin nor any additional monitoring of the anticoagulant effect of warfarin is necessary.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 667-669 
    ISSN: 1432-1041
    Keywords: Key words Cyclosporin ; Orlistat ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: We detected markedly decreased cyclosporin blood levels in a heart-transplanted patient after the gastrointestinal lipase inhibitor orlistat was accidentally added to the treatment program to control for his obesity. Therefore, we determined cyclosporin plasma concentration time kinetics with and without orlistat reexposition in this patient. Methods: Plasma concentration time kinetics of whole blood cyclosporin levels in an obese heart-transplant patient were measured using a standard monoclonal fluorescence polarisation immunoassay. Results were obtained in hourly intervals up to 12 h without and with co-therapy of 3 × 120 mg orlistat (Xenical, Roche Ltd., Switzerland). The orlistat re-exposition was started the day before taking blood samples. Results: Cyclosporin trough levels (98 ng/ml vs 52 ng/ml), maximum concentrations (532 ng/ml vs 74 ng/ml) and the area under the blood drug concentration-time curve (2832 ng h ml−1 vs 700 ng h ml−1) were greatly reduced with orlistat. Conclusions: Orlistat markedly decreased blood cyclosporin concentrations, possibly due to an interference with its absorption in the small intestine. To avoid potential dangerous under-immunosuppression, orlistat should not be used in patients taking cyclosporin.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    ISSN: 1432-1041
    Keywords: Key words AT1 receptor antagonist ; Blood pressure ; Candesartan cilexetil ; Candesartan ; Pharmacokinetics ; Renin angiotensin system
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: We studied the pharmacokinetics and pharmacodynamics of single and multiple doses of candesartan cilexetil 8 mg per day in hypertensive patients with different degrees of renal function impairment. Candesartan is an angiotensin II subtype 1 (AT1) receptor antagonist that is administered orally as candesartan cilexetil which is converted in the active compound. Methods: Twenty-three patients were included, divided into groups according to creatinine clearance (cr cl. group A 〉60 nl · min−1 · 1.73 m−2, group B 30–60 ml · min−1 · 1.73 m−2 and group C 15–30 ml · min−1 · 1.73 m−2). Results: Trough serum concentrations of candesartan were higher in group C compared with group A. The values did not increase after multiple dosing, indicating absence of accumulation. There was a significant negative correlation between the area under the concentration-time curve extrapolated to time infinity (AUCinf) and the glomerular filtration rate (GFR) indicating a lower renal clearance of candesartan in patients with impaired renal function. The onset of haemodynamic and hormonal effects was gradual. During the single-dose study blood pressure as well as plasma renin activity (PRA) and angiotensin II were unchanged at peak. At day 5 of the multiple-dose study blood pressure was lower and both PRA and angiotensin II were higher compared with baseline. Conclusion: Although serum trough levels increased during repeated administration and half-life was higher in patients with impaired renal function, candesartan cilexetil at a dose of 8 mg per day does not lead to drug accumulation in these patients. This dose is effective in lowering blood pressure and appears to be suitable for patients with renal function impairment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    ISSN: 1432-1041
    Keywords: Key words ABT-761 ; Pharmacokinetics ; Asthma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The pharmacokinetics of an N-hydroxyurea analog, ABT-761 in asthmatic pediatric patients with asthma were investigated. Methods: A total of 24 patients were enrolled into this 8-day single- and multiple-dose study. Patients received daily doses of ABT-761 according to their body weight: patients of 20–38 kg received 50 mg; patients 〉38 kg but ≤55 kg received 100 mg, and patients ≥55 kg received 150 mg. Results: The mean values for the terminal phase t1/2 were 16–17 h after multiple-dose administration. When normalized for body weight, the mean day 8 Clf values for 50-, 100-mg, and 150-mg doses were 0.57 (n = 13), 0.51 (n = 10), and 0.43 (n = 1) ml · min−1 · kg−1, respectively, while the mean Vz/f values ranged from 0.75 to 0.77 l · kg−1. The mean accumulation ratio observed (day 8 to day 1 AUC0–24 ratio) of ABT-761 was approximately 1.7, which is consistent with the t1/2 of this drug. Body weight, age, and body surface area were virtually identical in explaining the variability in dose-normalized Cmax and AUC values (R 2 = 0.61–0.68). The percents of variance explained by these three variables were within a range of 3% for each pharmacokinetic parameter. Conclusions: The pharmacokinetics of ABT-761 in children were similar to those previously reported in adults. Body weight, age, or body surface area can be used to provide dosing adjustment for ABT-761 in pediatric patients.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    ISSN: 1432-1041
    Keywords: Key words Oral contraceptives ; Nifedipine ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: To investigate the influence of oral contraceptives on cytochrome P450 3A4 (P450NF) activity. Methods: In 23 healthy women, the pharmacokinetics of nifedipine and its main metabolite dehydronifedipine in plasma were assessed after a single oral dose, prior to and after intake of one of two oral contraceptive formulations, one containing 2 mg dienogest and 0.03 mg ethinylestradiol (group A) and the other containing 0.125 mg levonorgestrel and 0.03 mg ethinylestradiol (group B). Results: While the intake of two oral contraceptives for 21 days did not influence the plasma concentration-time curve of unchanged nifedipine, mean AUC0–23.5 h and the mean Cmax values of dehydronifedipine were significantly lower in both groups tested/(24% in group A and 25% in group B). This observation may indicate a reduced formation rate of metabolites and reflects an inhibition of cytochrome P450 3A4 activity. The activation of the same or other metabolic degradation mechanism(s) could explain this result. Conclusion: The investigation presented demonstrates the importance of metabolite measurement when in vivo studies are undertaken to investigate different influences on drug metabolizing ability.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 54 (1998), S. 767-771 
    ISSN: 1432-1041
    Keywords: Key words Propiverine ; Fatty liver disease ; Pharmacokinetics ; Adverse effects
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The present study was designed to assess the pharmacokinetics of propiverine after single and multiple dosing in patients with and without fatty liver disease. Methods: The serum concentration-time curves of propiverine and its main metabolite propiverine-N-oxide were investigated in 12 patients with mild to moderate impairment of liver function (mean antipyrine clearance 26.0 ml · min−1) and in 12 controls (antipyrine clearance 42.8 ml · min−1). Subjects were treated orally with propiverine hydrochloride (Mictonorm) for 5 days (15 mg t. i. d.) to reach steady state. Results: No significant differences were observed for propiverine and its main metabolite with regard to peak serum concentration (Cmax), area under the serum concentration-time curve (AUC) and elimination half-life (t1/2). Adverse events were reported by 12 patients. Five patients with fatty liver disease and seven patients with normal liver function complained of dry mouth and/or blurred vision. All adverse events reported were transient and mild. Conclusion: No pharmacokinetic differences relevant for safety were observed, comparing patients with and without fatty liver disease following repeated oral administration of propiverine. Thus there seems to be no need to adjust the dose in patients with mild to moderate impairment of liver function.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    ISSN: 1432-1041
    Keywords: Key words Amlodipine ; Limited-sampling models ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Develop and validate limited-sampling strategy (LSS) models for estimating the area under the plasma concentration versus time curve (AUC) of amlodipine, using data from a bioequivalence study. Methods: Sixteen healthy volunteers received single 5-mg oral doses of amlodipine, as reference or test formulation, at a 14-day interval, in a randomized, crossover protocol. Plasma concentrations of amlodipine (n = 288), measured by mass spectrometry, were used to develop LSS models. Results: Linear regression analysis of the AUC0–72 and a “jack-knife” validation procedure revealed that LSS models based on two sampling times (12 h and 48 h) predict accurately (R2 = 0.99; bias〈0.01%; precision = 0.03%) the AUC0–72 of amlodipine for each formulation. Validation tests indicate that the 2-point LSS model developed for the reference formulation predicts accurately (R2〉0.90): (a) the individual AUC0–72 for the test formulation in the same group of volunteers; (b) the individual AUC0–72 for the same reference formulation in another bioequivalence study in Brazilian volunteers; (c) the average AUC0–72 reported in seven additional international studies performed under protocols similar to the present investigation; (d) the individual AUC0–72 corresponding to concentration data points provided by a first-order compartmental pharmacokinetic model, when the relative values of either the absorption rate (K abs) or the bioavailability (F) model parameters were set at 0.85 or 0.6, of their respective original values. Conclusions: The 2-point LSS models developed in the current study predict accurately the AUC of amlodipine under a variety of experimental conditions and, thus, may be valuable for exploring the relationships between the pharmacokinetics and pharmacodynamics of this calcium antagonist, at reduced costs of sample acquisition and analysis, and avoiding sampling at “unsociable” hours.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 677-680 
    ISSN: 1432-1041
    Keywords: Key words Dihydroergotamine ; Absorption ; Intranasal ; Randomly methylated β-cyclodextrin (RAMEB) ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: A comparison of the pharmacokinetic properties of two novel intranasal preparations of dihydroergotamine mesilate (DHEM) with a commercially available intranasal preparation. Methods: Two intranasal formulations of DHEM in combination with randomly methylated β-cyclodextrin (RAMEB) were prepared. Subsequently, in an open, randomised, crossover study in nine healthy volunteers, the following medication was administered: 2 mg DHEM/2% RAMEB nasal spray ( =two puffs of 100 μl); 2 mg DHEM/4 mg RAMEB nasal powder; 2 mg Diergo nasal spray ( =four puffs of 125 μl); 0.5 mg DHEM i.m., and 2 mg DHEM solution p.o. Results: No statistically significant differences were found in maximum plasma concentration (Cmax), time to reach Cmax (tmax), area under plasma concentration–time curve (AUC0–8 h), Frel(t=8 h) and Cmax/ AUC(t=8 h) for the three intranasal preparations. The relative bioavailabilities of the DHEM/RAMEB nasal spray, the DHEM/RAMEB nasal powder and the commercially available DHEM nasal spray were 25%, 19% and 21%, respectively, in comparison with i.m. administration. The relative bioavailability after oral administration was 8%. Conclusion: The pharmacokinetic properties of the novel intranasal preparations are not significantly different from the commercially available nasal spray. Advantages of the DHEM/RAMEB nasal spray are (1) less complicated handling, (2) reduction of the number of puffs and (3) a preference by the volunteers.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    ISSN: 1432-1041
    Keywords: Key words CYP2D6 ; Genetic polymorphism ; Metoprolol ; Pharmacokinetics ; Human
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Aim: The aim of the present paper was to compare the pharmacokinetics of metoprolol in homozygous Caucasian volunteers for the wild-type CYP2D6 allele (CYP2D6*1/CYP2D6*1) and heterozygous (CYP2D6*1/CYP2D6*4) Caucasians. Methods: Thirty-six unrelated healthy male Caucasians were screened for two of the most frequently occurring mutant alleles (CYP2D6*3 and CYP2D6*4) using polymerase chain reaction (PCR). Twenty-four volunteers with a genotype suggesting a rapid hydroxylator phenotype were enrolled in a bioequivalence trial and each received in a randomized, cross-over fashion one of the three formulations compared. Each formulation contained 200 mg metoprolol tartrate/(tablet). In each of the three periods of the trial, one of the formulations was administered under fasting conditions in the morning on 4 consecutive days. Blood for quantification of metoprolol was drawn immediately before the last dose and in selected time intervals thereafter. A sensitive and specific high-performance liquid chromatography (HPLC) method with fluorescence detection was applied for the quantification of metoprolol. Pharmacokinetic parameters were determined for each subject and statistically compared in two groups of 16 homozygous (CYP2D6*1/CYP2D6*1) and six heterozygous (CYP2D6*1/CYP2D6*4) volunteers. Results: Significant differences between homozygous and heterozygous individuals were observed for all pharmacokinetic parameters. The AUC in the course of one those interval of 24 h (AUCτ), minium steady-state concentration (Cmin ss) and average steady-state concentration (Cav ss) values for heterozygous individuals were more than twice those of individuals. Significantly higher values for Css max , t1/2, half-value duration (HVD) and mean residence time (MRT) were also observed in heterozygous volunteers. The higher concentrations of metoprolol in heterozygous individuals also had pharmacodynamic consequences, namely, greater heart rate and blood pressure reduction.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 54 (1998), S. 627-631 
    ISSN: 1432-1041
    Keywords: Key wordsl-NAME ; Pharmacokinetics ; Septic shock
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: The pharmacokinetics of N G-nitro-l-arginine methyl ester (l-NAME), an inhibitor of nitric oxide (NO) synthesis, was investigated in patients with septic shock. Methods: Blood was sampled at intervals before, during and after 12-h infusion of l-NAME 1 mg · kg−1 · h−1 in nine septic shock patients for determination of plasma concentrations by high-performance liquid chromatography (HPLC). In three patients the renal clearance of the drug was determined. Results: Incubation of l-NAME with plasma and blood in vitro revealed hydrolysis to N G-nitro-l-arginine (l-NOARG), the active inhibitor of NO synthesis. l-NOARG did not undergo further degradation. Continuous intravenous infusion of 1 mg · kg−1 · h−1 of l-NAME for 12 h in patients with septic shock increased blood pressure and resulted in increasing plasma concentrations of l-NOARG (Cmax 6.2 μg · ml−1 at 12 h) whereas l-NAME concentrations reached a plateau within 1.5 h (Cmax 1.0 μg · ml−1). After the infusion was stopped l-NAME disappeared from the plasma rapidly (half-life 19.2 min) whereas l-NOARG concentration declined slowly (half-life 22.9 h). The calculated volume of distribution for l-NAME was 0.45 l · kg−1 body weight and 1.96 l · kg−1 for l-NOARG. The renal clearance for l-NOARG was 3.5% of total body clearance for l-NOARG, whereas l-NAME could not be detected in urine. Conclusion: We conclude that vasoconstriction with l-NAME in septic patients may result from hydrolysis to l-NOARG, the active inhibitor of NO synthesis. The long plasma half-life and large volume of distribution for l-NOARG suggests extensive distribution to extravascular tissues. Since renal excretion is minimal, elimination of the metabolite l-NOARG follows other pathways.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    ISSN: 1432-1041
    Keywords: Key words Carboplatin ; Irinotecan ; Limited sampling model ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objectives: The aim of this study was to develop limited sampling models for estimating the area under the concentration-versus-time curve (AUC) of carboplatin. Methods: Based on pharmacokinetic analyses of 14 patients who received 300 mg · m2 of carboplatin over a 90-min infusion following irinotecan, we developed limited sampling models with stepwise multiple linear regression analysis. We validated these models to be unbiased and precise using pharmacokinetic data of a second group of 14 patients. We also compared the observed and the predicted AUC in the patients using Calvert's formula with the patients' renal function. Results: We developed the following models: AUC (mg · ml−1 · min) = 0.784 × C4 + 1.30 (r 2 = 0.930) and AUC = 0.100 × C0.25 + 0.597 × C4 + 0.140 (r 2 = 0.992), where C0.25 and C4 denote unbound plasma concentrations (μg · ml−1) of carboplatin at 0.25 h and 4 h after the end of infusion, respectively. These models were validated to be unbiased and precise: a mean prediction error (MPE) with standard deviation (SD) = 2.41 (9.45)% and a root mean squared error (RMSE) = 9.42% for the one-sample model, and MPE with (SD) = 1.22 (5.56)% and RMSE = 5.49% for the two-sample model. We also calculated predicted AUC in the patients using Calvert's formula: MPE with (SD) =−5.87 (21.5)% and RMSE = 21.5%. Conclusions: These estimations were, as expected, more accurate than the prediction using Calvert's formula based on patients' renal function. The result of this study confirmed the idea that the pharmacokinetic parameters derived from limited sampling models would be more suitable for pharmacokinetic analysis of carboplatin than those obtained using Calvert's formula.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 49-51 
    ISSN: 1432-1041
    Keywords: Key words Oxypolygelatine ; Pharmacokinetics ; Healthy volunteers ; Tolerability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective/methods: The pharmacokinetics of the plasma substitute oxypolygelatine (OPG) were studied in 12 healthy volunteers after single-dose administration of 27 ml · kg−1 body weight, with a maximum of 2000 ml. OPG was determined in plasma and urine over 48 h after the infusion. Peak plasma OPG concentrations at the end of the infusion were determined to 4.600 (623) μg · ml−1, the area under the plasma concentration/time curve (AUC0∞) was calculated to 70.135 (15.861) μg · h · ml−1. Results: The model-independently calculated volume of distribution came to 23.1 (4.8) l with a clearance total is (Cltot) of 24.6 (6.8) ml · min−1. The initial half-life according to a three-compartment model came to 0.3 (0.2) h, followed by a distribution half-life of 3.1 (2.6) h and a terminal elimination half-life of 13.4 (2.2) h. Cumulative urinary excretion of OPG was 64% after 48 h. Conclusion: This low recovery rate may be explained by the distribution of OPG into the extravascular space and subsequent degradation in tissue sites.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 221-226 
    ISSN: 1432-1041
    Keywords: Key words Clozapine ; Erythromycin ; CYP3A4 ; Pharmacokinetics ; Drug interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: To study the suggested pharmacokinetic interaction between erythromycin, a strong inhibitor of CYP3A4, and clozapine. Methods: Twelve healthy male volunteers received a single dose of 12.5 mg of clozapine alone or in combination with a daily dose of 1500 mg erythromycin in a randomised crossover study. Clozapine and its metabolites clozapine-N-oxide and desmethyl-clozapine were measured in serum samples which were collected during a 48 h period and in a sample of the urine secreted over the interval 0–12 h. Results: There were no significant differences in mean area under the serum concentration time curves (1348 (633) nmol h · 1−1 in the control phase and 1180 (659) nmol h · 1−1 in the erythromycin phase), terminal half-lives (19 (13) h and 15 (6) h, respectively), peak serum concentrations (92 (53) nmol · 1−1 and 77 (40) nmol · 1−1, respectively), time to peak serum concentrations (1.4 (0.7) h and 1.5 (1.0) h, respectively) or apparent oral clearances of clozapine (34 (15) l · h−1 and 46 (37) l · h−1, respectively). There were no significant differences in partial metabolic clearances to clozapine-N-oxide (5.1 (3.6) l · h−1 and 7.8 (9.4) l · h−1, respectively) or to desmethyl-clozapine (1.5 (1.3) l · h−1 and 1.8 (1.7) l · h−1, respectively) or in renal clearances of clozapine (0.8 (0.5) l · h−1 and 1.0 (0.7) l · h−1, respectively) between the two phases. Conclusion: These results demonstrate that erythromycin at a clinically relevant dosage does not inhibit the metabolism of clozapine. Hence, CYP3A4 seems to be of minor importance in the disposition of clozapine in humans at least when clozapine is taken at a low single dose.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    ISSN: 1432-1041
    Keywords: Key words Pregnanolone ; Pharmacokinetics ; Premenstrual syndrome
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Pregnanolone is a 3α-hydroxylated-5β-reduced metabolite of the female sex steroid hormone progesterone. The compound is currently being evaluated for anaesthetic purposes. Previous studies have indicated a differential physiological response across the menstrual cycle and a different response in patients with premenstrual syndrome (PMS). This study was undertaken to determine whether hormonal changes during the menstrual cycle influence pregnanolone pharmacokinetics and to compare PMS diagnosis-related differences in pregnanolone pharmacokinetics. Methods: Seven patients with premenstrual syndrome and seven female controls were given three increasing doses of pregnanolone in the follicular and luteal phase of the menstrual cycle. Results: Mean pregnanolone elimination half-life varied between 28.4 min and 31.8 min and clearance between 59.6 ml · min−1 · kg−1 and 64.0 ml · min−1 · kg−1, depending on diagnostic group and cycle phase. No significant differences in pregnanolone pharmacokinetic properties were found between PMS patients and controls in either phase of the menstrual cycle. Furthermore, no differences in pharmacokinetic variables were detected between cycle phases. Conclusion: Pregnanolone pharmacokinetics do not differ between follicular and luteal phase of the menstrual cycle, nor between PMS patients and control subjects.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 213-219 
    ISSN: 1432-1041
    Keywords: Key words Limited sampling ; Area under the curve ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objectives: To develop a method of limited sampling that would enable accurate estimation of the area under the concentration time curve (AUC) when using the log trapezoidal method. Methods: A series of datasets were simulated. Each dataset comprised 1000 subjects. Each subject was “administered” an intravenous bolus dose of a drug that displays two compartment pharmacokinetics. In the first series of simulations, a variety of combinations of the number of sampling times (K) and number of replicate measurements (R) at each of these times were tested, where K × R = 12 (i.e. N = 12). The times that each of the K samples were taken were chosen to be those that divided the AUC into K − 1 trapezoids of equal area. The concentration-time curves were estimated based on a priori estimates of the population parameters. The best combination of K and R was tested under various conditions of parameter variability and assay variability. The combinations were compared with a conventional sampling strategy, where N = 12, K = 12 (R = 1). Results: The combination K = 4 and R = 3 proved to be the “best”. It had similar accuracy to the conventional method. The best limited sampling combination was superior to the conventional method when assay variability was high (CV = 30%), was similar when assay variability was 15%, but the conventional method became statistically superior when assay variability was 7.5% or less. The accuracy of the best limited sampling combination was inversely related to the parameter variability. If K was set to 4 and R allowed to increase to 6 (i.e. N≠ 12), there was no further gain in accuracy. Conclusion: The proposed method of limited sampling is at least as accurate as the conventional intensive sampling technique, but more efficient in terms of sampling.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    ISSN: 1432-1041
    Keywords: Key words Elderly ; Pharmacokinetics ; Renal function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: It is commonly assumed that renal function, and in parallel the excretion of drugs, is considerably reduced in the elderly. Endogenous creatinine clearance or indirect estimates of this parameter are generally recommended for adapting drug dosage. The present study evaluates the validity of both assumptions. Methods: We compared pharmacokinetics (and pharmacodynamics) of 50 mg atenolol, 800 mg piracetam and 25 mg hydrochlorothiazide plus 50 mg triamterene in ten healthy young [25 (2) years] and 11 healthy elderly subjects [68 (5) years]. Inulin (Cin) and para-aminohippurate [PAH (CPAH)] clearance (infusion clearance technique), endogenous (CCr) and calculated (Cockroft-Gault) creatinine clearance, analysis of drugs and their metabolites (HPLC), were performed. Renal haemodynamics and the pharmacokinetics of β-adrenergic blocking agent, diuretics and the nootropic agent piracetam, respectively, were measured on separate days. Results: Cin was significantly (P 〈 0.01) lower in the healthy elderly subjects [104 (12) vs 120 (14) ml · min−2 · 1.73 m−2 in the young], but remained within the normal range (〉90 ml · min−2 · 1.73 m−2). In contrast, CCr was even lower in healthy elderly subjects [95 (24) vs 121 (20) ml · min−1 in the young], and the Cockroft-Gault clearance underestimated true glomerular filtration rate (GFR) even more seriously [74 (17) vs 122 (16) ml · min−1]. For atenolol the mean area under the curve (AUC) was similar in both groups [3.16 (0.48) μg · h−1 · ml−1 in the elderly vs 3.01 (0.30) in the young], as was the mean maximal plasma concentration [0.42 (0.07) vs 0.44 (0.06) μg · ml−1], but the proportion of the drug excreted in urine was marginally (P 〈 0.025) lower in the elderly. Similar results were obtained for hydrochlorothiazide, whereas no marked differences between the groups were found for triamterene and its metabolite. Furthermore, the pharmacodynamic action of diuretics was not significantly altered in the elderly. Conclusions: The true GFR of the healthy elderly remains within the normal range and is underestimated by creatinine clearance and more so by its surrogate (Cockroft-Gault clearance). In parallel, pharmacokinetics of renally excreted drugs are not affected in the healthy elderly to a clinically significant extent. For drugs with a narrow therapeutic window, indirect estimates of GFR appear to be an unreliable means for calculating correct dosage in the elderly.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    ISSN: 1432-1041
    Keywords: Keywords Verapamil ; Grapefruit juice ; Pharmacokinetics ; Hypertension
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: To investigate the effect of grapefruit juice (GJ) on the pharmacokinetics of orally administered verapamil in hypertensive patients. Methods: Ten hypertensive patients on chronic verapamil treatment participated in a two-day study. On day 1 200 ml of water was given 1 hour before, and together with the morning verapamil dose; on the day 2, water was replaced by GJ in the same order. Serial blood samples were collected and the concentrations of verapamil and its main dealkylated metabolite (D-617) were determined by high-performance liquid chromatography (HPLC). The area under the concentration versus time curve of verapamil (AUCv) and its metabolite D-617 (AUCM) were calculated before and after GJ ingestion. The peak serum concentration (Cmax) and the time until its appearance (tmax) were also determined. Results: GJ did not affect Cmax, tmax, AUCv or AUVm. The AUCv/AUCm ratio (AUCR) was slightly, but significantly, increased after GJ (1.67 vs 1.92). Conclusions: A single administration of GJ with short-acting verapamil has no significant effect on the pharmacokinetics, of verapamil.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 54 (1998), S. 411-414 
    ISSN: 1432-1041
    Keywords: Key words Artesunic acid ; Pharmacokinetics ; Malaria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: A single cross-over, comparative pharmacokinetic study of oral and rectal formulations of 200 mg artesunic acid in 12 healthy Malaysian volunteers is reported. Methods: Plasma concentrations of artesunic acid and dihydroartemisinin were determined simultaneously by HPLC with electrochemical detection. The test drug was well tolerated and no undesirable adverse effects were observed. Results: Comparison of pharmacokinetic parameters of artesunic acid after oral and rectal administration showed statistically significant differences in t max and AUC, with no changes for C max and t 1/2. As for dihydroartemisinin, differences were observed for t max and C max but not for AUC. Conclusion: There appear to be pharmacokinetic differences between oral and rectal modes of administration. The significance of these findings should be explored in malaria patients before appropriate therapeutic regimens are devised.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 77-78 
    ISSN: 1432-1041
    Keywords: Key words Pirmenol ; Arrhythmia ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 393-398 
    ISSN: 1432-1041
    Keywords: Key words Grapefruit juice ; Quinine ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: As quinine is mainly metabolised by human liver CYP3A4 and grapefruit juice inhibits CYP3A4, the effect of grapefruit juice on the pharmacokinetics of quinine following a single oral dose of 600 mg quinine sulphate was investigated. Methods: The study was carried out in ten healthy volunteers using a randomised cross-over design. Subjects were studied on three occasions, with a washout period of 2 weeks. During each period, subjects received a pretreatment of 200 ml orange juice (control), full-strength grapefruit juice or half-strength grapefruit juice twice daily for 5 days. On day 6, the subjects were given a single oral dose of 600 mg quinine sulphate with 200 ml of one of the juices. Plasma and urine samples for measurement of quinine and its major metabolite, 3-hydroxyquinine, were collected over a 48-h period and analysed by means of a high-performance liquid chromatography method. Results: The intake of grapefruit juice did not significantly alter the oral pharmacokinetics of quinine. There were no significant differences among the three treatment periods with regard to pharmacokinetic parameters of quinine, including the peak plasma drug concentration (Cmax), the time to reach Cmax (tmax), the terminal elimination half-life (t1/2), the area under the concentration–time curve and the apparent oral clearance. The pharmacokinetics of the 3-hydroxyquinine metabolite were slightly changed when volunteers received grapefruit juice. The mean Cmax of the metabolite (0.25 ± 0.09 mg l−1, mean ± SD) while subjects received full-strength grapefruit juice was significantly less than during the control period (0.31 ± 0.06 mg l−1, P 〈 0.05) and during the intake of half-strength grapefruit juice (0.31 ± 0.07 mg l−1, P 〈 0.05). Conclusion: These results suggest that there is no significant interaction between the parent compound quinine and grapefruit juice, so it is not necessary to advise patients against ingesting grapefruit juice at the same time that they take quinine. Since quinine is a low clearance drug with a relatively high oral bioavailability, and is primarily metabolised by human liver CYP3A4, the lack of effect of grapefruit juice on quinine pharmacokinetics supports the view that the site of CYP inhibition by grapefruit juice is mainly in the gut.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    ISSN: 1432-1041
    Keywords: Key words Entacapone ; Levodopa ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Entacapone is a peripherally acting catechol O-methyltransferase (COMT) inhibitor used as an adjunct to each daily levodopa/dopa decarboxylase (DDC) inhibitor dose in the treatment of Parkinson's disease. Parkinsonian patients with advanced disease and motor fluctuations take several doses of levodopa daily, due to the short action of levodopa in this patient population. The present study was conducted in order to evaluate the pharmacokinetics of entacapone after multiple dosing and the pattern of COMT inhibition in erythrocytes during the first day of dosing as well as during steady state. Furthermore, the disposition of plasma levodopa and carbidopa was studied after a single dose of levodopa/carbidopa during the same conditions. Methods: Twelve healthy male volunteers received 200 mg entacapone eight times daily during study day 1 and day 6 at 2-h intervals from 0800 hours to 2200 hours. During days 3, 4 and 5, 200 mg of entacapone was taken ten times daily, from 0800 hours to 0200 hours on the following day. One levodopa/carbidopa tablet (100/25 mg) was taken on study day 1 and day 6 at 1000 hours. Plasma entacapone concentrations and erythrocyte COMT activities were measured frequently on study days 1–2 and 6–7, and twice daily on study days 3–5. Pharmacokinetic parameters calculated from plasma drug concentrations on days 1–2 and 6–7 were compared with each other. Results: There were no differences in maximal plasma concentration (Cmax), time to maximal drug concentration in plasma (tmax), elimination half-life (t1/2) and area under the plasma concentration–time curve (AUC) of entacapone between day 1 and day 6. The mean t1/2 values of entacapone were 1.3 h and 1.8 h during the first and sixth days, respectively; the difference was not significant. No signs of accumulation of entacapone were noted after the first day. Entacapone reduced erythrocyte COMT activity after the first dose, and this effect was quite stable during frequent dosing. There were no indications of accumulation of COMT inhibition during frequent dosing of entacapone. There were no between-day differences in Cmax, t1/2 (2.4 h on days 1–2 and 2.3 h on days 6–7) or AUC of levodopa, whereas tmax occurred at 0.8 h on day 1 and at 1.2 h on day 6 (P = 0.03). There were no between-day differences in the pharmacokinetic parameters (Cmax, tmax and AUC) of carbidopa. Conclusion: Even when dosed frequently, there are neither indications of accumulation of entacapone nor of its COMT inhibiting activity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Electronic Resource
    Electronic Resource
    Springer
    European journal of clinical pharmacology 55 (1999), S. 475-478 
    ISSN: 1432-1041
    Keywords: Key words Cyclosporin ; Dipyrone ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Background: A large number of drugs have been shown to affect the metabolism of cyclosporin A (CSA) and, since cyclosporin is characterized by a narrow therapeutic range, the consequences of such drug interactions may often be of clinical importance. Objective: To evaluate the effect of short-term administration of dipyrone on steady state CSA pharmacokinetics. Methods: Six kidney- and two heart-transplanted patients on chronic CSA therapy participated in this study, which consisted of two 4-day study periods separated by 3-week washout periods. The patients received, in addition to their usual drugs, dipyrone 500 mg or placebo t.i.d., as identical-looking tablets, and the order of administration was randomized. CSA concentrations were measured in whole blood by means of radio-immunoassay (CYCLO-Trac SP) daily during the study periods and periodically over 24 h on the fourth study day. Results: CSA concentrations over time were reduced after dipyrone (ANOVA, P 〈 0.01), but statistical significance was noted only at 2, 4, 5 and 10 h after drug intake (P 〈 0.05). Peak CSA concentration was not altered by dipyrone, but the time required to reach maximal concentration was longer with dipyrone treatment than with the placebo (3.8 ± 2.6 h vs 2.1 ± 0.6 h, P 〈 0.05). No consistent changes were noted for CSA trough level, elimination half-life and area under the concentration–time curve from 0 h to 12 h. Separate analysis of the kidney transplanted patients yielded similar results. Conclusions: Short-term administration of dipyrone is associated with a mild decrease in CSA blood concentration, which is most prominent in the first few hours after drug intake. In practice, no dose adjustment of CSA seems to be indicated during a short course of dipyrone treatment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 52 (1998), S. 863-870 
    ISSN: 1572-8943
    Keywords: calcium hydroxide ; hydration ; limestone cement ; non evaporable water ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Subject of this paper is to investigate the hydration process of Portland limestone cement containing 10-35% limestone. Cements, produced by co-grinding of clinker, limestone and gypsum, were hydrated for periods 6 h to 28 d and were studied by means of TG and XRD. The Ca(OH)2 content of the cements containing limestone is higher than in pure cements, specifically for 10% limestone content and ages more than 1 day. These results are in accordance with the strength development of the studied cements. In earlier ages the Ca(OH)2 content is slightly lower in the limestone cements and independent of the limestone content. After 1 day curing, the increase of limestone addition causes a relative increase of the non evaporable water. The XRD patterns indicated the presence of carboaluminates in the hydrated limestone cements.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 53 (1998), S. 71-85 
    ISSN: 1572-8943
    Keywords: DSC ; enantiomer ; IR ; powder X-ray diffractometry ; racemate ; TG ; thermomicroscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The physicochemical characterization of the solid-state enantiomers and racemate of efaroxan hydrochloride (C13H17N2O+Cl-, M=252.5 g mol-1) was performed by thermoanalytical methods (differential scanning calorimetry, thermogravimetry and thermomicroscopy) and spectral methods (infrared spectrometry and X-ray diffractometry). The efaroxan enantiomers and racemate were shown to be unstable near the melting point. At the beginning of the decomposition, a loss of hydrogen chloride was observed. However when sealed pans were used, the compounds decomposed at higher temperature, allowing a precise evaluation of the melting enthalpies by means of differential scanning calorimetry. The nature of the racemate and its thermal stability were assessed by evaluating its free formation enthalpy. An enantiotropic solid-solid transformation (II→I) was noted for the racemate; the reverse process (I→II) follows zero-order kinetics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 53 (1998), S. 365-374 
    ISSN: 1572-8943
    Keywords: compositional analysis ; event separation ; heating rate ; MaxRes ; softening ; TG ; TMA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Conventional thermogravimetric analysis (TG) uses constant heating rates to determine decomposition rates of a material and compositional analysis. Often, the decomposition steps can not be separated clearly enough due to parallel or consecutive reactions. If the reaction rates and the respective activation energies are enough different the TG resolution can be much enhanced by lowering the heating rate during the decomposition steps. The automated discrete adjustment of the heating rate is controlled by a set of parameters, such as threshold values, waiting times and rate factors. This technique, called MaxRes, allows for faster compositional analysis without loss of resolution. The same technique is also applicable to thermomechanical analysis (TMA) if time/temperature dependent events such as softening are to be separated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 53 (1998), S. 487-492 
    ISSN: 1572-8943
    Keywords: calcite ; calcium polyphosphates ; dolomite ; phase transformation ; TG ; X-ray
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal interactions of dolomite and calcite with calcium polyphosphates up to 1000°C were studied by thermal (dynamic heating and isobaric conditions) and X-ray diffraction methods. It was found that in mixtures with Ca-polyphosphates less than half of the carbonates reacted before decomposition to oxides with the phosphates. The rates of the reactions of phosphates with MgO were much lower than those with CaO. The scheme of the main crystalline phase transformations was constructed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 67-76 
    ISSN: 1572-8943
    Keywords: activation energy ; DSC ; ethylene-vinyl acetate copolymer ; TG ; TG/IR ; thermal degradation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract When ethylene-vinyl acetate copolymer, EVA, is heated, a two-stage thermal degradation occurs following its melting. The vinyl acetate content of the copolymer was determined to be 43.8% by using TA 2950 and TA 2050 thermogravimetric instruments. TG/FTIR was used to detect the evolved gas. Acetic acid and trans-1-R-4-R'-cyclohexane were the main products evolved from EVA in the first and second stage, respectively. The apparent activation energies were determined for both stages by differential methods.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 93-98 
    ISSN: 1572-8943
    Keywords: degradation ; DTA ; flame retardant ; IR ; pyrolysis ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal degradation of cotton cellulose treated with chemical mixtures containing P and N was studied by thermal analysis, infrared spectroscopy, Char yield and limiting-oxygen-index (LOI). Our experiments demonstrated the following facts. The temperatures and activation energies of pyrolysis were lower for cotton cellulose treated with flame retardants than those for untreated samples and the values of Char yield and LOI were greater for treated cotton than those for untreated one.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 841-849 
    ISSN: 1572-8943
    Keywords: cobalt(II)-dothiepin ; kinetics ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The complexes of cobalt(II) with dothiepin (DOT) hydrochloride have been studied for kinetics of thermal degradation by thermogravimetric analysis (TG) and derivative thermogravimetric studies (DTG) in a static nitrogen atmosphere at a heating rate of 10° C min−1. A general mechanism of thermal decomposition is advanced involving dehydration and decomposition process for both organic and inorganic ligands. The thermal degradation reactions were found to proceed in three steps having an activation energy in the range 6.75–170 kJ mol−1. Thermal decomposition kinetics parameters were computed on the basis of thermal decomposition data.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 297-303 
    ISSN: 1572-8943
    Keywords: β-zeolite ; coke ; cumene ; kinetics ; regeneration ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract An accurate description of coke burn off is obtained from a catalyst based on β-zeolite and used for benzene alkylation with propylene giving cumene by using the thermogravimetric technique. A simple empirical kinetic model was successfully applied to interpolate the data of thermogravimetric analysis performed on samples after partial burn off. Different temperatures, partial pressures of oxygen and gas flow rates were the variables studied in order to calculate the apparent rates and the activation energy for the coke oxidation reaction and to outline the best conditions for the industrial regeneration procedure of our proprietary catalyst PBE-1 for cumene synthesis. Combining the unusually long lifetime per reaction cycle with the optimized regeneration procedure leads to an outstanding overall catalyst life.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 337-343 
    ISSN: 1572-8943
    Keywords: DTA ; DTG ; immobilized cinchonidine ; Pt/K-10 montmorillonite ; TG ; thermal stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The characterization of new cinchonidine doped K-10 montmorillonite supported noble metal catalysts is described. Our aim was the mapping of thermal stability of these new catalytic materials by thermogravimetry (TG), differential thermogravimetry (DTG) and differential thermoanalysis (DTA) methods accompanied by X-ray diffraction (XRD) measurements. The catalysts were prepared by various methods including conventional, microwave and ultrasonic treatments. They were characterized first by X-ray diffraction to verify the stability of montmorillonite crystal structure during preparation. Then, TG and DTG methods were applied to determine their stability under the experimental conditions usually applied. The main changes observed were the loss of water and the decomposition of the organic modifiers in the higher temperature region. The catalyst showed the best performance were prepared and characterized using microwaves and ultrasonic irradiation in order to get more insight to the effect of preparation methods on their stability. As a consequence, the catalysts were found to be stable and regenerable under 450-500 K, however, higher temperatures resulted in the complete destruction of the catalysts.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 541-546 
    ISSN: 1572-8943
    Keywords: acetate ; DTA and IR ; halogenoacetates ; Mg(II) ; pyridine ; SCN ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract TG, DTA and other analytical methods were applied to investigate the thermal behaviour and structures of the compounds Mg(ClAc)2(Py)2·2H2O (I), Mg(Cl2Ac)2(Py)·H2O (II), Mg(Cl3Ac)2(Py)·6H2O (III) and Mg(SCN)2(Py)3·2H2O (IV), where ClAc=ClCH2COO−, Cl2Ac=Cl2CHCOO−, Cl3Ac=Cl3CCOO− and Py=Pyridine. The compositions of the complexes and the solid-state intermediates and products of thermolysis were identified by means of elemental analysis. Possible schemes of destruction of the complexes are suggested. The final products of the thermal decompositions were MgO (I–III) and MgS (IV). The IR data suggest unidentate coordination of the carboxylate ions to Mg(II) in complexes I–III. Py is coordinated to the Mg(II) through the nitrogen atom of its heterocyclic ring.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 479-484 
    ISSN: 1572-8943
    Keywords: copper thiocarbamide complex ; DTA ; spray pyrolysis ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Hydrated isostructural 1:3 complexes of copper(I) chloride and bromide with thiourea were synthesised and their thermal decomposition studied by simultaneous TG/DTA complemented by ex situ FTIR and XRD studies. The decomposition of Cu(tu)3Cl·H2O is initiated by dehydration around 100°C, followed by a total multi-step degradation of the structure in the temperature range of 200–600°C. The counter ion has some influence on the temperatures and composition of the solid residue. The results were compared with those obtained with the 1:1 complex Cu(tu)Cl·1/2H2O.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 1059-1063 
    ISSN: 1572-8943
    Keywords: dehydration ; miscibility ; NMR ; polymer blend ; poly(2-hydroxyethyl methacrylate) (PHEMA) ; poly(methacrylic acid) (PMAA) ; TG ; TMDSC
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Miscibility and dehydration of poly(2-hydroxyethyl methacrylate) and poly(methacrylic acid) (PHEMA/PMAA) blends were investigated by temperature modulated DSC (TMDSC), TG and solid-state 13C NMR methods. TMDSC spectra and 1H spin-relaxation times showed that the blends are homogeneous on a scale of 5-10 nm for all compositions. From TG and 13C NMR, we elucidated that the mass loss of the blends at 300°C is ascribed to the dehydration between the hydroxyl group of PHEMA and the carboxyl group of PMAA.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 1093-1096 
    ISSN: 1572-8943
    Keywords: activation energy ; aromatic polyamide ; benzimidazolyl-substitution ; TG ; thermal stability
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The TG studies are presented for isomers of benzimidazolyl-substituted polyamides (BIPA). The TG data are compared with those polyamides (PA) of identical backbones without substitution, in view of the mechanism of thermal degradation. The TG mass loss curves divided to three temperature ranges reflect the decomposition reactions in the respective temperature ranges: (1) cleavage of single bonds of nitrogen to aromatic ring, (2) random scission of single bonds, (3) condensation of the remained rings. Liberation of benzimidazole rings occurs in the temperature range (2). The final product, char, contains benzimidazole rings. Terephthaloyl-rich BIPA's retard liberation of benzimidazole from the decomposed polymer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 1285-1304 
    ISSN: 1572-8943
    Keywords: amorphous state ; combined techniques ; drug design ; drug product development ; drug substance ; drug technology ; DSC ; excipients ; failure investigations ; hydrates ; MDSC ; microcalorimetry ; pharmaceuticals ; polymorphism ; polymers ; preformulation ; process optimization ; purity ; quality control ; solvates ; stability ; sub-ambient DSC ; TG ; temperature resolved X-ray diffraction ; water interactions ; thermal microscopy ; water sorption-desorption
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Modern thermal analysis, microcalorimetry and new emerging combined techniques which deliver calorimetric, microscopic and spectroscopic data offer a powerful analytical battery for the study of pharmaceuticals. These techniques are very useful in all steps of development of new drug products as well as methods for quality control in production. The characterization of raw materials enables to understand the relationships between polymorphs, solvates and hydrates and to choose the proper development of new drug products with very small amount of material in a very short time. Information on stability, purity is valuable for new entities as well as for marketed drug substances from different suppliers. Excipients which vary from single organic or inorganic entity to complexes matrixes or polymers need to be characterized and properly controlled. The thermodynamic phase-diagrams are the basis of the studies of drug-excipients interactions. They are very useful for the development of new delivery systems. A great number of new formulations need proper knowledge of the behaviour of the glass transition temperature of the components. Semi-liquid systems, interactions in aqueous media are also successfully studied by these techniques.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 57 (1999), S. 61-73 
    ISSN: 1572-8943
    Keywords: amorphous ; combined techniques for polymorphism ; DSC ; MKS 492 ; polymorphism ; purine ; quantitative determination ofamorphous and polymorphs ; solvent mediated transitions ; temperature resolved X-ray diffraction ; TG ; thermodynamic relation between polymorphs ; xanthine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The polymorphic behaviour of the purine derivative MKS 492 was studied with investigations of suspensions of selected samples in different solvents and of samples obtained by crystallizations. The samples were analyzed by DSC, TG and X-ray diffraction. Six different crystalline modifications called A, B, B’, C, D and E and an amorphous form were identified. Four pure crystalline modifications, A, B, C and D have been manufactured and characterized by DSC, X-ray, IR, solubilities, densities, hygroscopicity and dissolution measurements. The four forms A, C, D and E are monotrop to the form B. The form B is enantiotrop to the form B’, which revealed the highest melting point of all known polymorphs. This form B’ is only stable at high temperature. Temperature resolved X-ray diffraction was very helpful for proper interpretation of the thermal events. The melting peaks of the forms A and C and the endothermic peak corresponding to the enantiotropic transition B into B’ occur in a narrow range of temperature. The form B which is the most stable one at room temperature has been chosen for further development. Quantitative methods to determine the content of the forms A, C and D in samples of form B or to determine the content of form A, B and D in form C have been developed by using X-ray diffraction. Limits of detection are 1 or 2%. For the quantitative determination of the amorphous fraction, X-ray diffraction and microcalorimetry are compared. For high amounts of the amorphous fraction, the X-ray diffraction method is preferred because it is faster. Microcalorimetry is very attractive for levels below 10% amorphous content. The lowest limit of detection is obtained by microcalorimetry, about 1%.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 355-362 
    ISSN: 1572-8943
    Keywords: Curie temperature ; nanocrystalline ; TG ; TG(M) and DTG(M)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The σ—T and dσ/dT—T curves of the FeCuNbSiB amorphous alloy, which are the relationship between the total saturated magnetic moment per unit mass σ and temperature, are investigated by magnetic thermogravimetry analysis (TG(M)) technique. It is found that the crystallization process of the samples can be divided into five stages. The studies of samples annealed in temperature range of 480–610°C for 1h show that when the annealing temperature (Ta) is less than 540°C, the quantity of nanocrystalline α-Fe(Si) phase increases evidently with Ta, and the Curie temperature (TC) of residual amorphous phase also increases linearly with Ta, i.e. TC=0.52Ta+91.7°C, with correlation coefficient γ=0.98. The variation of volume fraction of α-Fe(Si) nanocrystalline phase or residual amorphous phase with Ta is measured by TG(M) technique.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    ISSN: 1572-8943
    Keywords: first order autocatalytic reaction ; HNNC ; kinetics ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The kinetics of the first order autocatalytic decomposition reaction of highly nitrated nitrocellulose (HNNC, 14.14%N) was studied by using thermogravimetry (TG). The results show that the TG curve for the initial 50% of mass-loss of HNNC can be described by the first order autocatalytic equation $$\frac{{{\text{d}}y}} {{dt}} = - 10^{16.4} \exp \left( { - \frac{{210380}} {{RT}}} \right)y - 10^{16.7} \exp \left( { - \frac{{171205}} {{RT}}} \right)y(1 - y)$$ and that for the latter 50% mass-loss of HNNC described by the reaction equations $$\frac{{dy}} {{dy}} = - 10^{16.3} \exp \left( { - \frac{{169483}} {{RT}}} \right)y\quad (n = 1)$$ and $$\frac{{dy}} {{dt}} = - 10^{16.8} \exp \left( { - \frac{{165597}} {{RT}}} \right)y^{2.61} \quad (n \ne 1)$$
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 671-675 
    ISSN: 1572-8943
    Keywords: chemically modified zeolite thermochemical properties ; DTA ; emanation thermal analysis ; TG ; zeolite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Zeolites chemically modified with 1, 4 or 6 M aqueous solutions of NaOH were studied by DTA, TG and ETA (emanation thermal analysis) in the temperature range 201–200°C. The structural changes in the modified zeolites at room temperature and in the modified zeolites annealed at 1000°C were studied by XRD analysis. Thermal analysis demonstrated dehydration, dehydroxylation, structural changes and a glass transition. A gradual loss in crystallinity of the chemically modified zeolites was also observed. XRD analysis revealed structural changes caused by chemical treatment and also by annealing.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 653-662 
    ISSN: 1572-8943
    Keywords: dehydration ; DSC ; TG ; water ; zeolites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A procedure for measurement of the heat of zeolite dehydration by scanning heating has been designed. Simultaneous data on heat flow (DSC) and mass loss (TG) are required for evaluation. The heating rate depends on the experimental conditions (point-spread function, sample mass, crucible design, and calorimetric reproducibility). Dehydration measurements have three advantages as compared with the sorption procedure: i) one can investigate samples with irreversible dehydration; ii) no approximation model is needed for calculation of the partial molar heat of dehydration; and iii) the procedure is not labor-consuming. The procedure was tested on the natural zeolites heulandite, chabazite and mordenite. The results are close to those measured by the sorption procedure. The partial molar heat of dehydration was found to depend on the water content. It increases from 50 to 87 J mol−1 K−1 for heulandite, from 53 to 81 J mol−1 K−1 for chabazite, and from 51 to 71 J mol−1 K−1 for mordenite. The approximation of the heat of sorption by linear regression was found to be wrong. Detection of a ‘phase transitioN’ after this approximation has no meaning.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 53 (1998), S. 895-904 
    ISSN: 1572-8943
    Keywords: crosslinking ; differential scanning calorimetry ; polyaniline ; post-polymerization ; relaxation transition ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal behaviour of polyaniline-‘emeraldine base’ (PANI-EB) was studied using thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). We assume that during heating over 150°C three exothermal processes proceed - reorganization and crosslinking between PANI-EB chains followed by post-polymerization. The low temperature relaxation transition for PANI-EB was registered for the first time by DSC. We suppose that it might be due to the motion of polymer chains non-crosslinked during the first heating, chain fragments resulting from high-temperature decomposition over 300°C and chain ends of the already crosslinked polymer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 54 (1998), S. 63-69 
    ISSN: 1572-8943
    Keywords: DTA ; IR ; K0.5Bi0.5TiO3 ; PbZrO3 ; solid solution ; TG ; XRD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract DTA, TG, XRD and IR methods were used to study the formation of solid solutions in the selected subsolidus range of the PbZrO3-K0.5Bi0.5TiO3 system by heating mixtures prepared using oxide substrates, i.e. PbO, Bi2O3, ZrO2, TiO2 and K2CO3. It was found that solid solutions are formed in the reaction of PbO and ZrO2 with intermediate compound, i.e. K0.5Bi0.5TiO3. PbZrO3 was not found to be formed as an intermediate phase.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 54 (1998), S. 369-379 
    ISSN: 1572-8943
    Keywords: compensation effect ; dimensionless analysis ; DTG ; error levels ; evaluation ; kinetic parameters ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract It follows from an analysis of the error levels of TG evaluation methods that it is a conceptual error to disregard the analogies of mass, energy and momentum streams of subordinate partial processes. This error is bypassed by means of the introduced method of dimensionless analysis and by determining the characteristic, constants-like data of thermal processes by using the measured data directly. These methods are very suitable for increasing the consistency of the calculated results by seeking for similarity, even in comparisons of measurements made under very different conditions and for emphasizing the differences too, quantitatively. With this new interpretation of TG processes, the idea of the kinetic compensation effect becomes only a consequence of the discussed conceptual error.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    ISSN: 1572-8943
    Keywords: activation energies ; degradation behaviour ; epoxy resin ; master curves ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract A study of an epoxy-cycloaliphatic amine system has been realized using a thermogravimetric technique (TG). Isothermal and non-isothermal (dynamic) methods were employed to determine the kinetic data of this system. Five methods were used for determining the activation energies of this system in the dynamic heating experiments. In two of them (Flynn-Wall-Ozawa, and Kissinger) it is not necessary to have a prior knowledge of the reaction mechanism of the degradation behaviour for this system. In the other ones (Coats and Redfern, Horowitz and Metzger, and Van Krevelen et al.) it is necessary to know this reaction mechanism, besides Criado et al. method was used for determining it. The results have shown that good agreement between the activation energies obtained from all methods can be achieved if it is assumed that the degradation behaviour of this system is of sigmoidal-rate type.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 789-796 
    ISSN: 1572-8943
    Keywords: alkaline earth malonates ; DSC ; DTA ; kinetic parameters ; TG ; thermal decomposition
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal decomposition of strontium and barium malonates has been studied isothermally and non-isothermally employing simultaneous TG-DTG-DTA, DSC, XRD and IR spectroscopic techniques. DSC of these malonates has been recorded both in oxygen and nitrogen atmospheres. The decomposition is a single step process and the end product formed is carbonate. The energy of activation and frequency factor values for the decomposition of strontium malonate are 547 kJ mol−1 and 1041 s−1 respectively. The activation energy and frequency factor values for isothermal dehydration of barium malonate sester-hydrate are 57–111 kJ mol−1 and 107–1012 s−1 respectively and the corresponding values for decomposition from DSC are 499.5 kJ mol−1 and 1044 s−1 respectively. The higher thermal stability of strontium malonate as compared to that of barium salt is ascribed to its being anhydrous so that decomposition proceeds without restructuring. Their thermal stabilities have also been compared with that of respective oxalate salts.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 7-15 
    ISSN: 1572-8943
    Keywords: ALE ; CVD ; DSC ; DTA ; EGA ; EL display ; solar cell ; sol-gel ; spray pyrolysis ; super-conductor ; TG ; thin films
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Processing thin films for advanced applications, for instance in electronics and optoelectronics, involves several steps starting from precursor synthesis and ending up with the devices. Especially when optimizing the first steps of this chain of processes, thermoanalytical techniques play an important role. The review will focus on the main chemical deposition methods (CVD, ALE, spray pyrolysis, sol-gel) giving selected examples of problem-solving by thermal analysis. The techniques discussed are TG, DTA/DSC, EGA and their combinations. High-temperature X-ray diffraction (HTXRD) is also a powerful tool for in situ studies of thin films. The examples are taken from solar cell, superconductor and flat panel electroluminescent display technologies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 429-435 
    ISSN: 1572-8943
    Keywords: DSC ; nickel sulphide ; TG ; toughened glass ; X-ray diffraction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Nickel sulphide (NiS) was characterised using X-ray diffraction, thermal gravimetric analysis (TG) and differential scanning calorimetry (DSC). The 'as received' Millerite, stoichiometric NiS, observed to be slightly nickel deficient, was found to readily decompose in a nitrogen atmosphere at elevated temperatures (450°C max.) to the sulphur deficient Godlevskite, Ni7S6. DSC and X-ray measurements demonstrated that the high temperature form of the Godlevskite was readily stabilised at room temperature. The kinetics of the α-β re-transformation in Godlevskite were then investigated using DSC and were observed to be first order.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 1389-1396 
    ISSN: 1572-8943
    Keywords: FT-IR ; fuel ; oil ; pyrolysis ; residue ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Although thermogravimetric analysis (TG) has become an indispensable tool for the analysis and characterization of materials, its scope is limited as no information is obtained about the qualitative aspects of the evolved gases during the thermal decomposition. For processes involving mass loss, a powerful technique to provide this missing information is Fourier transform infrared spectroscopy (FT-IR) in combination with TG. It supplies a comprehensive understanding of thermal events in a reliable and meaningful way as data are obtained from a single sample under the same conditions. The coupling TG/FT-IR is used in fuel analysis for the identification of residual volatiles, to determine their sequence of release and to resolve thermogravimetric curves. In this work, the usefulness of TG/FT-IR for characterizing middle distillate fuel residues is illustrated with some typical examples of recent application. A Bio-Rad FTS 25 FT-IR spectrometer coupled with a TA Instruments TGA 2950 thermogravimetric analyzer was used for data aquisition. The results obtained demonstrate the utility of this combined technique in determining the decomposition pathway of tarry materials at various stages of pyrolysis, thereby allowing new insights into the complex thermal behaviour of hydrocarbon residual systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 1123-1131 
    ISSN: 1572-8943
    Keywords: compatibility ; decomposition ; energetic materials ; peak temperature ; polymers ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Compatibility is an important safety aspect related to the production and storage of energetic materials. To test different combinations of materials a simple test method with clear criteria is advisable. At the last ESTAC the use of microcalorimetry and the vacuum stability test for the compatibility testing of propellants were presented. This paper presents DSC, DTA/TG and (pressure) vacuum stability test results for the same combination. For three polymers (PMMA, PVC and CA) the results for all tests are the same. Only Nylon-6/6 gives a variable result for the different test methods.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 1353-1357 
    ISSN: 1572-8943
    Keywords: DSC ; terpenoids ; TG ; thermal behaviour
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The terpenoids acetyl sitosterol, lupeol, acetyl diosgenin and stigmasterol were studied. Comparison of the thermogravimetric curves and the activation energies of the terpenoids suggested the following sequence of thermal stability: acetyl sitosterol 〈 acetyl diosgenin 〈 lupeol 〈 stigmasterol. The DSC curves allowed determination of the melting points and the degrees of purity. Comparison of the TG and DSC curves revealed the presence of phase transitions without mass loss that were attributed to rearrangements in the terpenoid molecules.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 309-315 
    ISSN: 1572-8943
    Keywords: dispersion threshold value ; Mn2O3/γ-Al2O3 catalyst ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Mn2O3/γ-Al2O3 catalysts were prepared by the impregnation method, and the maximum monolayer dispersion capacity or dispersion threshold value of Mn2O3 on the surface of γ-Al2O3 was determined to be 13.08% from the decomposition mass loss of supported Mn(NO3)2 in the monolayer state. This was compared with the values estimated from a close-packed monolayer model and an interaction model. It was confirmed that the high activities and selectivities of the catalysts for benzoic acid hydrogenation to benzaldehyde are due to the monolayer dispersion of the Mn2O3 on the surface of γ-Al2O3.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    ISSN: 1572-8943
    Keywords: coordination compounds ; CRTA ; TG ; quasi-equilibrium ; thermodynamics ; volatility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Quasi-equilibrium thermogravimetry (with sample holders specially calibrated for the vapour pressure) was used for thermoanalytical screening of volatile compounds. ‘p-T’ relationships (in the range 0.0006 to 0.11 at) were obtained for acetylacetonates and fluoroacetylacetonates of Al, Cr and Zr. The incorporation of the trifluoromethyl group into the acetylacetone ligand noticeably increases the volatility: the enthalpy of evaporation remains practically constant, but the evaporation entropy changes distinctly.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 52 (1998), S. 145-155 
    ISSN: 1572-8943
    Keywords: acrylates ; DMA ; DSC ; epoxides ; radiation curing ; structure-property relationship ; TG ; thermal analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Thermo-oxidative and thermo-mechanical stabilities of radiation-cured acrylates and epoxides were examined by TG, DMA and DSC. The polymeric trifunctional acrylates PETIA, TMPTA and THEIC displayed the highest temperatures of onset of degradation. The high crosslinking density of the films resulted in an almost temperature-independent complex E-modulus, as measured by DMA. With increasing degree of ethoxylation or propoxylation of the monomers, decreases in thermal stability and strength were found. For difunctional polymeric acrylates and epoxides, the glass transition temperature was measured. The average degree of curing of UV-cured epoxy films can be determined from the temperature of the maximum in the loss modulus (E″max.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 52 (1998), S. 221-233 
    ISSN: 1572-8943
    Keywords: DTA ; DTG ; highly additivated plastics ; MS ; recycling ; soft-PVC waste ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Within a research project, a new process for the recycling of soft-PVC waste has been developed. Additionally to the economic significance, the material is predestined to serve as a model system for plastics with high additive contents.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 53 (1998), S. 649-658 
    ISSN: 1572-8943
    Keywords: calcination ; limestone ; phase analysis ; porosity ; reactivity ; SEM ; sulphation ; sulphur oxide capture ; texture ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The reactions occurring between CaCO3/CaO and SO2/SO3 in oxidizing atmospheres are discussed. Calcination and sulphation were carried out in a thermobalance under conditions relevant to atmospheric fluidized bed combustion. It is suggested that the quality of limestones as potential SO2 sorbents can be assessed on the basis of tests carried out in a TG apparatus adapted for use with corrosive gases. Limestone calcined under different conditions including the treatment with NaCl leads to changes in surface texture. Sulphated samples were examined in a SEM by energy dispersive X-ray and backscattered electron imaging. Two sulphur-bearing solids (CaSO4 and CaS) were identified. The sulphation rate and extent are determined by the product layer diffusion. The amount of CaS present at the end of the process depends on the particle size of the sorbent.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 833-840 
    ISSN: 1572-8943
    Keywords: acidity ; ammonium perchlorate ; basicity ; characterization ; DTG ; metal oxides ; pyrolysis ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Six metal oxide samples were prepared by calcination of the corresponding precursors at 500°C for 5 h in air and were characterized by IR and XRD analyses. Their surface areas were calculated by means of the BET method. The acidities and basicities of these metal oxides were estimated thermogravimetrically by the method of adsorption of pyridine and formic acid as probe molecules. The pyrolyses of pure ammonium perchlorate (AP) and of AP mixed with (10% w/w) metal oxide were studied, in a dynamic atmosphere of N2, by thermogravimetric analysis (TG) and derivative thermogravimetric analysis. A correlation was found between the catalytic activities of the metal oxides during the pyrolysis of AP, and their acidic-basic characters. The activation energies of the non-catalyzed and catalyzed pyrolysis of AP were calculated from the TG results via the Coats-Redfern equation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 773-777 
    ISSN: 1572-8943
    Keywords: aerogel ; calcination ; hydrophylicity ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Differences in mass loss occurring in the course of dynamic and isothermal heating of SiO2-aerogel and changes of specific surface and hydrophylicity during calcination were studied by thermal analysis. SiO2-aerogel was prepared from tetramethoxysilane (TMOS) hydrolyzed by ammonia solution at 0°C with molar ratio TMOS: H2O:NH4OH 4:1:0.01. Differences are caused mainly by oxidation of organic matter and by diffusion of products of the oxidation. Heat transfer has none or little effect on the differences. Samples calcined at temperatures about 300°C reach maximum hydrophilicity though they still contain small amounts of residual organic matter.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 55 (1999), S. 995-1002 
    ISSN: 1572-8943
    Keywords: benzoic acid ; DTA ; DTG ; hydroxy- and aminobenzoic acids ; o-phthalic acid ; principal component analysis ; sulphanilic acid ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The thermal decomposition of benzoic acid and its derivatives containing —OH, —NH2, —COOH and —SO3H functional groups as substituents in ortho, meta and (or) para position together with sulphanilic acid was investigated. The analyses were performed using derivatograph, sample mass ranged from 50 to 200 mg, heating rates from 3 to 15 K min−1 and static air atmosphere. It has been established that thermal decomposition of these aromatic acids proceeds through three common stages. In the first stage the phase transformations occur. The following two stages are due to the formation of intermediate products of the thermal decomposition and their combustion. Principal component analysis (PCA) was applied for evaluation of the results. Thanks to this method the influence of specific functional groups and their positions on the benzene ring on the thermal decomposition of the compounds under investigation was determined.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 56 (1999), S. 1323-1327 
    ISSN: 1572-8943
    Keywords: chloramphenicol ; DSC ; quality control ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The stability and thermal behaviour of chloramphenicol and various of its mixtures were investigated. The thermogravimetric and stability constant results showed that the chloramphenicol base is thermally more stable than the tablet in the studied formulation. The reduction in stability was attributed to the presence of starch in the formulation. The thermal decompositions of the chloramphenicol base and the tablet obey first-order kinetics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    ISSN: 1572-8943
    Keywords: coordinationcompounds ; CRTA ; kinetics ; polymerization ; pyrolysis ; quasi-equilibrium ; TG ; thermolysis ; volatility
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Quasi-equilibrium thermogravimetry (variant of CRTA) is put to use as an express method of thermoanalytical screening for volatile compounds. During the experiments for P—T relationship calculations (running with several calibrated standard sample holders) the non-volatile (polymerized) residue is formed (and is decomposed with further temperature rising). Thermogravimetric data are used for the calculation of the kinetic parameters for the polymerization reaction, taking place (concurrently with the evaporation) in the melt of the studied volatile compound.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 301-307 
    ISSN: 1572-8943
    Keywords: acrylamide ; FT-IR ; N,N-dialkylacrylamide ; plasma-initiated polymerization ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Polyacrylamide (PAM), poly(N,N-dimethylacrylamide) (PDMA) and poly(N,N-diethylacryl-amide) (PDEA) were synthesized by plasma-initiated polymerization. Both wet and dry polymers were prepared. The states of the water absorbed in the wet and dry samples were studied directly by means of TG, and the stabilities of the dry polymers in the process of thermal treatment were investigated by FT-IR. The activation energy of release of the bonded water was calculated by the Kissinger method. The water absorbed in the polymers was found to be in two states, i.e. weakly-bonded water and bonded water, and the absorbed water content varied with the monomer concentration, the plasma duration time and the type of polymer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 375-381 
    ISSN: 1572-8943
    Keywords: benzene alkylation ; carbondeposition ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In our invention, FCC (fluid catalytic cracking) dry gas could be used to react with benzene without any special purification, and more than 90% ethylene was converted to ethylbenzene. The phenomenon of carbon deposition over catalyst surface was obvious and leads to a deactivation of catalyst, so it is important to study the behavior of carbon deposition of catalyst during alkylation of benzene. The influence of several factors such as temperature, reaction time, reactant concentration of the amount and the kinetics of carbon deposition were investigated, during which carbon depositing rate equations were obtained for different reactant.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Electronic Resource
    Electronic Resource
    Springer
    Journal of thermal analysis and calorimetry 58 (1999), S. 447-453 
    ISSN: 1572-8943
    Keywords: coal ; combustion reaction ; kinetics ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The combustion behavior of Shuangya Mountain (SYM) coal dust has been investigated by means of TG in this paper. The reaction fraction α can be obtained from isothermal TG data. The regressions of g(α), an integral function of α vs. t for different reaction mechanisms were performed. The mechanism of nucleation and nuclei growth is determined as the controlling step of the coal dust combustion reaction by the correlation coefficient of the regression, and the kinetic equation of the SYM coal dust combustion reaction has been established.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical ecology 25 (1999), S. 1555-1565 
    ISSN: 1573-1561
    Keywords: Yeasts ; Botrytis cinerea ; apple ; volatiles ; gray mold ; biological control ; fungal interaction ; acetate esters
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract The fungus, Botrytis cinerea, causes decay in apples in postharvest storage. Conidia of B. cinerea on polycarbonate membranes were incubated on filter paper disks saturated with water or suspensions of yeasts (2 × 106 CFU/filter) and then exposed for 24 hr at 22°C to 0–16 μl of ethyl, butyl, or hexyl acetates injected into the headspaces of 500-cc glass jars. Germination of conidia was increased by exposure to 4–16 μl of ethyl acetate compared to the no-ester controls. Conidia were stimulated to germinate by 4 μl of butyl acetate and 8 μl of hexyl acetate, but greater volumes were toxic to germination. The yeasts Cryptococcus laurentii and Sporobolomyces roseus were more effective at reducing the stimulatory effect than Saccharomyces cerevisiae. Acetate esters also stimulated germination of conidia on polycarbonate membranes on apples inside jars. Cryptococcus laurentii or S. roseus suppressed this effect more than S. cerevisiae. Germination of conidia on a membrane on water inside a 3.9-liter jar containing an apple was 2.5-fold greater than the no-apple control. Butyl acetate increased Botrytis infection of apple wounds. Butyl and hexyl acetate were detected by GLC in the headspace of Golden Delicious apples. Results indicated that some acetate esters produced by apple stimulated germination of B. cinerea conidia, and this effect was suppressed by yeasts.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    ISSN: 1871-4528
    Keywords: bioassay ; biological control ; blackleg ; green crop harvesting ; haulm killing ; skin damage ; wound protection ; Solanum tuberosum L
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Summary Green crop lifting (GCL) for haulm killing was developed in The Netherlands and offers ideal conditions for controlling the blackleg pathogenErwinia carotovora subsp.atroseptica (Eca) by antagonists. Based on the use of mini-tubers or young tubers from field crops, two bioassays for wound protection were developed. GCL was simulated by artificially skinning or wounding tubers, inoculating the damaged skin with Eca, treating with antagonists and incubating in either potting compost or outside in field soil. Mainly fluorescent pseudomonads, pre-screened for in vitro antagonistic activity on agar and high soft rot reducing ability on tuber slices, were tested in the mini-tuber bioassay. Strains giving the highest degree of wound protection were further tested individually and in combination under field conditions in the young tuber bioassay. One individual strain and two combinations, resulting in reduction of contamination levels on skinned surfaces of 85% and between 60% and 70%, respectively, show good potential for biological control of blackleg.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Electronic Resource
    Electronic Resource
    Springer
    Molecular breeding 5 (1999), S. 561-568 
    ISSN: 1572-9788
    Keywords: wheat ; milling yield ; QTL mapping ; RFLP ; microsatellite
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract A partial genetic linkage map constructed using 150 single seed descent (SSD) lines generated from a cross between the hexaploid wheat varieties ‘Schomburgk’ and ‘Yarralinka’ was used to identify loci controlling milling yield. Milling yield data were obtained using seed collected from field trials conducted at different sites over two seasons. The estimated broad-sense heritability of milling yield in this population was calculated as 0.48. In the preliminary analysis, two regions were identified on chromosomes 3A and 7D, which were significantly associated with milling yield and accounted for 22% and 19% of the genetic variation, respectively. Bulked segregant analysis in combination with AFLP identified other markers linked to these loci, as well as an additional region on chromosome 5A, which accounted for 19% of the genetic variation. The applicability of these markers as selection tools for breeding purposes is discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    ISSN: 1572-9788
    Keywords: insect resistance ; aphids ; GNA ; lectins ; transgenic plants ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Transgenic wheat plants containing the gene encoding snowdrop lectin (Galanthus nivalis agglutinin; GNA) under the control of constitutive and phloem-specific promoters were generated through the particle bombardment method. Thirty-two independently derived plants were subjected to molecular and biochemical analyses. Transgene integration varied from one to twelve estimated copies per haploid genome, and levels of GNA expression from 0 to ca. 0.2% of total soluble protein were observed in different transgenic plants. Seven transgenic plants were selected for further study. Progeny plants from these parental transformants were selected for transgene expression, and tested for enhanced resistance to the grain aphid (Sitobion avenae) by exposing the plants to nymphal insects under glasshouse conditions. Bioassay results show that transgenic wheat plants from lines expressing GNA at levels greater than ca. 0.04% of total soluble protein decrease the fecundity, but not the survival, of grain aphids. We propose that transgenic approaches using insecticidal genes such as gna in combination with integrated pest management present promising opportunities for the control of damaging wheat pests.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    ISSN: 1572-9788
    Keywords: wheat ; DNA markers ; yellow rust resistance ; Yr17
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The Yr17 gene, which is present in many European wheat cultivars, displays yellow rust resistance at the seedling stage. The gene introduced into chromosome 2A from Aegilops ventricosa was previously found to be closely linked (0.5 cM) to leaf and stem rust resistance genes Lr37 and Sr38, respectively. The objective of this study was to identify molecular markers linked to the Yr17 gene. We screened with RAPD primers, for polymorphism, the DNAs of cv. Thatcher and the leaf rust-resistant near-isogenic line (NIL) RL 6081 of cv. Thatcher carrying the Lr37 gene. Using a F2 progeny of the cross between VPM1 (resistant) and Thésée (susceptible), the RAPD marker OP-Y15580 was found to be closely linked to the Yr17 gene. We converted the OP- Y15580 RAPD marker into a sequence characterized amplified region (SCAR). This SCAR marker (SC-Y15) was linked at 0.8 ± 0.7 cM to the Yr17 resistance gene. We tested the SC-Y15 marker over a survey of 37 wheat cultivars in order to verify its consistency in different genetic backgrounds and to explain the resistance of some cultivars against yellow rust. Moreover, we showed that the Xpsr150-2Mv locus marker of Lr gene described by Bonhomme et al. [6] which possesses A. ventricosa introgression on the 2A chromosome was also closely linked to the Yr17 gene. Both the SCAR SC-Y15 and Xpsr150-2Mv markers should be used in breeding programmes in order to detect the cluster of the three genes Yr17, Lr37 and Sr38 in cross progenies.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    ISSN: 1573-739X
    Keywords: anaesthesia ; Clinical pharmacology ; Emulsion formulation ; Fat emulsion ; Propofol ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In a pilot study on the first application of Propofol 6% SAZN in humans, the pharmacokinetics and safety of the new product seem to be similar to those of Propofol 1% SAZN and Diprivan®‐10 after bolus injection. The results will have to be confirmed in a larger clinical study in order to develop Propofol 6% SAZN as an alternative for Diprivan®‐10.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    Electronic Resource
    Electronic Resource
    Springer
    Pharmacy world & science 20 (1998), S. 83-87 
    ISSN: 1573-739X
    Keywords: Dextromoramide ; HPLC determination ; Liquid‐liquid extraction ; Methadone ; Methadone maintenance therapy ; Palfium® ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract To study the pharmacokinetics of dextromoramide in long‐term opiate addicts on methadone maintenance therapy (MMT) a reverse‐phase HPLC technique was developed to monitor dextromoramide and methadone concentrations in plasma simultaneously. After liquid‐liquid extraction from plasma, dextromoramide and methadone were determined using a Supelcosil LC‐ABZ column and a mobile phase of KH2phosphate buffer (25 mM, pH 2.5) mixed with acetonitrile (80:20, v/v) and UV detection at 206 nm. The method was found to be sufficiently sensitive, specific and reproducible to apply in six subjects on MMT for many years, receiving orally administered dextromoramide as adjuvant. Pharmacokinetic data sets for dextromoramide in each subject were conducted and analysed further, indicating short elimination half‐life values (71 min, range 31‐152 min). Contrary to previous studies, in all subjects tested the pharmacokinetics of dextromoramide are best described using an one‐compartment model.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    ISSN: 1573-739X
    Keywords: Quinine ; Acute falciparum malaria ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The pharmacokinetics of quinine were studied in six Nigerian patients during acute uncomplicated falciparum malaria and convalescent periods. An oral dose of 10 mg/kg quinine dihydrochloride administered 8‐hourly for 7 days gave parasite and fever clearance times of 36.0 ± 16.6 h and 18.0 ± 6.4 h, respectively. From the individual quinine plasma profiles the mean plasma concentration of quinine at the time of parasite clearance was estimated as 4.5 ± 1.1 μg/ml. Plasma quinine levels during malaria rose rapidly reaching a peak around the second and third days and declining thereafter as patients improved clinically. In acute malaria plasma quinine levels were more than two-fold higher than in convalescence; the mean AUC(0-12) in malaria was 37.9 ± 14.7 μg.h/ml compared to 17.9 ± 8.5μg.h/ml in convalescence. The apparent oral clearance (CL/F) and volume of distribution (Vd/F) duri ng the acute phase of the malaria (1.9 ± 0.7 ml/min/kg and 1.8 ± 0.9 l/kg, respectively) were significantly lower than in convalescence (4.5 ± 2.1 ml/min/kg and 4.2 ± 3.2 l/kg). The present data suggest that malaria parasites in African patients are still very sensitive to quinine and that the current dosage of quinine is effective for the treatment of acute falciparum malaria in African patients without augmenting therapy with any other drug such as tetracycline or sulphadoxine-pyrimethamine. It also confirms that malaria significantly alters the pharmacokinetics of quinine in humans.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    ISSN: 1573-739X
    Keywords: Human placenta ; Drug transfer ; Drug transport ; Pharmacokinetics ; Placenta perfusion ; Membrane vesicles ; Cotyledon ; Trophoblast ; Cell culture
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In this review we summarized literature data on the mechanisms of human placental drug transport studied in the isolated perfused placental cotyledon, placental membrane vesicles or trophoblastic cell cultures. Overall human placental drug transport rarely exceeds the transfer of flow‐dependent and membrane‐limited marker compounds. Interestingly, relatively often placental drug transfer appeared to be much smaller, indicating impaired trans-placental transport, depending on the physico-chemical characteristics of the drug or placental factors such as tissue binding or metabolism. Although in perfusion studies overall human placental drug transport occurs by simple diffusion, at the membrane level several drug transport systems have been found, mainly for drugs structurally related to endogenous compounds.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    Electronic Resource
    Electronic Resource
    Springer
    Pharmacy world & science 20 (1998), S. 183-192 
    ISSN: 1573-739X
    Keywords: Hepatic disease ; Cirrhosis ; Pharmacokinetics ; Pharmacodynamics ; Dosage adjustment
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The liver plays a central role in the pharmacokinetics of many drugs. Liver dysfunction may not only reduce the plasma clearance of a number of drugs eliminated by biotransformation and/or biliary excretion, but it can also affect plasma protein binding which in turn could influence the processes of distribution and elimination. In addition, reduced liver blood flow in patients with chronic liver disease will decrease the systemic clearance of flow limited (high extraction) drugs and portal‐systemic shunting may substantially reduce their presystemic elimination (first‐pass effect) following oral administration. When selecting a drug and its dosage regimen for a patient with liver disease additional considerations such as altered pharmacodynamics and impaired renal excretion (hepatorenal syndrome) of drugs and metabolites should also be taken into account. Consequently, dosage reduction is necessary for many drugs administered to patients with chronic liver disease such as liver cirrhosis.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    ISSN: 1573-739X
    Keywords: Chemotherapy ; Colorectal cancer ; Fluorouracil ; Folinate ; Leucovorin ; Pharmacokinetics ; Toxicity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The optimum dose of calcium folinate (leucovorin) as modulator of fluorouracil has not been defined yet. We conducted a randomized trial to compare the pharmacokinetics/pharmacodynamics of two doses of calcium folinate. 16 patients with advanced colorectal cancer were treated with 650 mg/m2/d fluorouracil as 5 day continuous infusion and randomized to receive either 20 mg/m2 or 100 mg/m2 calcium folinate as short infusion twice daily. The two diastereoisomers of calcium folinate were analyzed separately by chiral HPLC to account for differences in their pharmacokinetics. The pharmacokinetics of fluorouracil was not affected by folinate dosing. Total clearance of the active (6S)-diastereoisomer was found to be lower after the higher dose of folinate which can be explained by nonlinear metabolism. The incidence of treatment‐induced mucositis significantly increased with (6S)‐folinate exposure, whereas fluorouracil exposure was not related to this type of toxicity. In conclusion, exposure to folinate is more important for toxicity in this regimen than fluorouracil pharmacokinetics. Therefore, monitoring of fluorouracil plasma levels is not useful in this combination. Our results show that folinate dose should be carefully selected. Lower doses of folinate might be preferred because of less toxicity compared to higher doses.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Electronic Resource
    Electronic Resource
    Springer
    Pharmacy world & science 20 (1998), S. 149-160 
    ISSN: 1573-739X
    Keywords: Antibiotics ; Cystic Fibrosis ; Pharmacokinetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The disposition of many drugs in cystic fibrosis is abnormal compared with healthy individuals. In general, changes include an increased volume of distribution expressed in liters per kg bodyweight for highly hydrophilic drugs such as aminoglycosides, and, to a lesser extent, for penicillins and cephalosporins, together with an increased total body clearance. The main reason for the increased volume of distribution is the increased amount of lean tissue per kg bodyweight, since patients with CF are generally undernourished and have a paucity of adipose tissue. The reason for the increased renal clearance is less clear. Increased glomerular filtration and tubular secretion have been observed. Protein binding generally is unaltered in CF. The fluorquinolones and vancomycin show no altered pharmacokinetics in CF although gastro-intestinal absorption may be delayed for fluorquinolones. Sulphamethoxazole shows increased clearance due to an increased acetylation and, in the case of trimethoprim, renal clearance is increased compared with healthy individuals. As a consequence, drugs that show increased clearance, will lead to reduced serum concentrations and smaller AUCs and therefore CF patients require larger doses per kg bodyweight.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 104 (1998), S. 29-36 
    ISSN: 1573-8469
    Keywords: biological control ; Zea mays ; Pythium spp. ; Fusarium spp. ; seed bacterization Burkholderia cepacia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Burkholderia cepacia (syn. Pseudomonas cepacia) strain PHQM100 applied as a seed coating was tested in growth chamber experiments for its ability to suppress preemergence damping-off, and postemergence damping-off in corn induced by Pythium and Fusarium spp. The symptoms observed in bioassays with soils naturally infested with the fungal pathogens were seed rot with Pythium spp. and mesocotyl and root tissue necrosis in the presence of Fusarium spp. Three corn cultivars that differed in their susceptibility to damping-off pathogens were used. Cultivar L was susceptible to pre- and postemergence damping-off, whereas cv. LPDP and cv. LG11 were moderately resistant and resistant to the damping-off diseases respectively. In the presence of Pythium spp., seed treatment with B. cepacia reduced seed rot, as compared to the untreated seeds, and this reduction was more consistent in the cv. LPDP than in the resistant cv. LG11 or the susceptible cv. L. In soils infested with Fusarium spp., seed treatment significantly reduced root and mesocotyl necrosis as compared to the untreated seeds, and this reduction was more consistent in the resistant cultivars LG11 and LPDP than in the susceptible cv. L. Root colonization levels by B. cepacia were similar in the three corn cultivars tested. Biocontrol efficiency of B. cepacia varied among cultivars mainly due to the differences in their susceptibility to the fungal pathogens. In spite of variability and also irrespective of the soil characteristics, B. cepacia increased seedling emergence and decreased mesocotyl and root necrosis when used as a seed coating.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    ISSN: 1573-8469
    Keywords: Central Europe ; powdery mildew ; wheat ; complexity of pathotypes ; Erysiphe graminis f.sp. tritici ; stabilizing selection ; survey ; virulence analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract In 1993–1996, the virulence of regional populations of the wheat powdery mildew pathogen (Erysiphe graminis DC f. sp. tritici Marchal) from the Czech Republic, Austria, Hungary and Slovakia against 13 resistance genes was investigated. The populations differed mainly at the regional level. Populations from the Czech Republic, mainly from the western regions, showed higher values of virulence against the Pm4b gene. Lower frequency of virulence against Pm4b was found in Austria, and the lowest value was observed in Hungary. The differences in frequencies of virulence against Pm4a and Pm4b showed a similar geographic pattern across the four countries: a continuous decline from west to east and from north to south. Virulence against Pm2 decreased in all countries considered; virulence to pm5, Pm6, Pm8 and Mli was high throughout. Genes and gene combinations that can ensure a relatively effective biological protection against this pathogen across Central Europe at present are Pm3b, Pm2+Mld and Pm1+2+9. Czech and Slovak populations were the most complex: virulence complexity reached a maximum in Slovakia in 1994. A similar evolution, though less significant, was observed in the Czech Republic. Data on complexity of isolates suggest that Central European populations of wheat powdery mildew tend to reach an intermediate level representing the optimal number of virulence genes. This process is probably a consequence of stabilizing selection.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    ISSN: 1573-8469
    Keywords: autoinduction ; biological control ; gene regulation ; LuxR/LuxI ; N-acyl-homoserine lactones ; fluorescent pseudomonads ; quorum sensing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract An emerging area within biological control is the role of N-acyl-homoserine lactones (N-acyl-HSL's) in the regulation of competitive fitness and pathogen suppression. N-acyl-HSL regulatory systems utilize two conserved proteins which belong to the LuxR/LuxI regulatory family: one is a transcriptional regulator and the second produces the N-acyl-HSL signal. These signals regulate the expression of a diverse range of bacterial traits involved in microbe-microbe and host-microbe interactions. Several fluorescent pseudomonads important in biological control produce N-acyl-HSL signals which regulate genes that encode products involved in pathogen suppression. In contrast to pathogenic bacteria, little is known regarding N-acyl-HSL-mediated gene regulation in biological control bacteria. This minireview will focus on the current status of the role of N-acyl-HSL's in the regulation of phenazine antibiotic and rhamnolipid production in biological control by fluorescent pseudomonads. The potential relevance of this type of regulation in biological control of plant diseases, and areas requiring further research will be addressed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    ISSN: 1573-8469
    Keywords: citrus bacterial canker ; detection ; epidemiology ; monoclonal antibodies ; variability ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Strains of Xanthomonas axonopodis pv. citri were isolated from Mexican lime (Citrus aurantifolia) trees in several countries in southwest Asia. These strains produced typical erumpent bacterial canker lesions on Mexican lime but not on grapefruit (C. paradisi). Lesions on grapefruit were watersoaked and blister-like in contrast to the typical erumpent lesions seen after artificial inoculation with all described pathotypes of X. axonopodis pv. citri. This group of strains hydrolysed gelatin and casein and grew in the presence of 3% NaCl as is typical of X. axonopodis pv. citri pathotype A. RFLP analyses and DNA probe hybridization assays also gave results consistent with X. axonopodis pv. citri pathotype A. Metabolic fingerprints prepared with the Biolog® system showed similarities as well as differences to X. axonopodis pv. citri pathotype A. In spite of the physiological and genetic similarities to pathotype A of X. axonopodis pv. citri, these strains had no or very little affinity for polyclonal antiserum prepared against any of the reference strains of X. axonopodis pv. citri and also did not react with monoclonal antibody A1, an antibody that detects all strains of pathotype A of X. axonopodis pv. citri. These strains were also insensitive to bacteriophage Cp3 like X. axonopodis pv. citri pathotype A and unlike X. axonopodis pv. citri pathotype B. We conclude that these strains, designated Xcc-A*, represent a variant of X. axonopodis pv. citri pathotype-A with pathogenicity limited to C. aurantifolia. The existence of extensive genotypic and phenotypic variation within pathotype A of X. axonopodis pv. citri was unexpected and further complicates the systematics of this species.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 105 (1999), S. 629-641 
    ISSN: 1573-8469
    Keywords: wheat ; Triticum spp. ; Septoria tritici ; septoria tritici blotch of wheat Stagonospora nodorum ; stagonospora nodorum blotch of wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    ISSN: 1573-8469
    Keywords: Bacillus thuringiensis ; biological control ; Helicotylenchus multicinctus ; nematicide ; numerical response ; Paecilomyces marquandii ; Radopholus similis ; Streptomyces costaricanus ; wheat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The effect of 24 treatment combinations of cultures of Streptomyces costaricanus sp. nov. (ATCC55274), Bacillus thuringiensis (ATCC55273) and a strain of Paecilomyces marquandii, nematicide (cadusaphos), and/or wheat mash on growth and response of potted banana plants (Musa AAA) and populations of Radopholus similis, Helicotylenchus multicinctus and free living nematodes were studied in Río Frío, Costa Rica. The best plant responses (height, leaf numbers, healthy root weight), lowest numbers of plant parasitic nematodes and highest numbers of free living nematodes were observed for treatments containing wheat as a component. Two treatments, viz. wheat + Streptomyces costaricanus (200-ml culture) and wheat + P. marquandii (200-ml culture), gave the overall best results. Numbers of free living nematodes increased up to 1500-fold only for treatments containing wheat. Significant positive correlations existed between numbers of free living nematodes and shoot weight, healthy root biomass, plant height, and leaf numbers. Non-wheat treatments, including nematicide only, gave the poorest responses in general. Observations of nematodes sampled 50 days following planting in wheat-containing treatments showed most of the free-living nematodes (≈ 90%) to be infected by nematophagous fungi (species not recorded). The results show that an organic amendment to soil, with or without a microbial component, can be an effective inducer of processes that regulate plant-parasitic nematode populations in soil.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 105 (1999), S. 123-137 
    ISSN: 1573-8469
    Keywords: Aureobasidium pullulans ; biological control ; Cryptococcus albidus ; grey mould ; Trichoderma harzianum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The efficacy of Trichoderma harzianum T39 and the yeasts Aureobasidium pullulans and Cryptococcus albidus against Botrytis cinerea in cucumber and tomato was compared with chemical control. Four experiments were conducted in cucumber grown under different climatic conditions in The Netherlands, and two experiments were done in tomato both in the Netherlands and in Israel. T. harzianum and A. pullulans showed the most consistent control of B. cinerea, reducing stem lesions and death of plants by 40–100% in most cases. Control of stem lesions and subsequent wilting was generally better than control of symptoms on fruits. In some cases, the biocontrol agents were more effective than the broad-spectrum fungicide tolylfluanid and the selective fungicide iprodione. The climatic conditions did not strongly influence the efficacy of the biocontrol agents, but regression analysis showed that high temperature during the day and high vapour pressure deficit during the night reduced biocontrol efficacy. From the results, prospects for biocontrol of B. cinerea in greenhouse vegetables appear good under a range of conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Electronic Resource
    Electronic Resource
    Springer
    European journal of plant pathology 105 (1999), S. 95-101 
    ISSN: 1573-8469
    Keywords: bacteria ; biological control ; Chryseobacterium ; Flavobacterium ; grey mold ; Pseudomonas ; strawberries
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Most potential fungal antagonists have been identified only after exhaustive non-selective screening. Bacteria antagonistic to Botrytis cinerea were selected using a simple method based on techniques developed for trace enrichment studies, where a crude cell wall preparation from B. cinerea was used as a selective substrate and bacteria were isolated based on growth on cell wall agar media. Most of the 52 bacterial isolates that were obtained from the surface of ‘organically grown’ strawberry fruit and could grow on B. cinerea wall media in culture showed some ability to inhibit the growth of the fungus. Potato dextrose agar seeded with B. cinerea spores (104 ml−1) were challenged with each of these bacterial isolates at concentrations of 109 and 106 colony forming units ml−1. Eleven of the 52 isolates initially recovered, subsequently demonstrated strong antagonism in vitro and were selected for additional screening tests on strawberry fruit. All 11 isolates reduced grey mold rot incidence on fruit in storage. Three of the best isolates were tested in limited field trials, and also reduced grey mold rot on fruit under field conditions.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    ISSN: 1573-8469
    Keywords: in vitro interactions ; biological control ; rhizosphere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Fusarium wilt diseases, caused by the fungus Fusarium oxysporum, lead to significant yield losses of crops. One strategy to control fusarium wilt is the use of antagonistic, root-colonizing Pseudomonas spp. It has been demonstrated that different strains of these bacteria suppress disease by different mechanisms. Therefore, application of a mixture of these biocontrol strains, and thus of several suppressive mechanisms, may represent a viable control strategy. A prerequisite for biocontrol by combinations of biocontrol agents can be the compatibility of the co-inoculated micro-organisms. Hence, compatibility between several Pseudomonas spp. strains, that have the ability to suppress fusarium wilt of radish, was tested in vitro on KB agar plates. Growth of P. fluorescens strain RS111 was strongly inhibited by Pseudomonas spp. strains RE8, RS13, RS56 and RS158, whereas a mutant of strain RS111 (RS111-a) was insensitive to inhibition by these strains. Strains RS111 and RS111-a only slightly inhibited some other strains. Suppression of fusarium wilt of radish in a potting soil bioassay by the incompatible combination of RE8 and RS111 was comparable to the effects of the single strains. However, disease suppression by the compatible combination of RE8 and RS111-a was significantly better as compared to the single strains. In contrast, the incompatible combination of RS56 with RS111 resulted in enhanced disease suppression as compared to the single strains. Increased disease suppression by combinations of RS13 or RS158 with RS111 or RS111-a was not observed. This indicates that specific interactions between biocontrol strains influence disease suppression by combinations of these strains.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Electronic Resource
    Electronic Resource
    Springer
    Journal of systems integration 9 (1999), S. 167-185 
    ISSN: 1573-8787
    Keywords: flexibility ; complexity ; systems approach ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science
    Notes: Abstract In this paper we present a taxonomy of manufacturing problems, labeled in a general sense as Design, Production, or Distribution problems. One or more basic systems concepts, such as complexity and adaptation, attach themselves to each such problems. By combining the hierarchical Design—Production—Distribution idea with system concepts, we establish the fact that there is, indeed, a significant systems component to most problems of modern manufacturing.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    ISSN: 1573-5036
    Keywords: AP PCR ; Erwinia ; Klebsiella ; nitrogen-fixing bacteria ; phytopathogenicity ; ribosomal DNA ; taxonomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Enterobacteria isolates from potato tubers were able to fix nitrogen, to protect plants against phytopathogens and to produce phytohormones thus increasing the plant yield. These isolates were previously phenotypically identified as Erwinia carotovora; however, they differed from typical E. carotovora in a number of biological characteristics and were found to be nonphytopathogenic (avirulent) due to the lack of pectate lyase activity. A data matrix, containing 31 strains and 105 biological characteristics was used for computer cluster analysis. The avirulent strains formed a separate cluster more closely related to Klebsiella spp. strains (with a 0.67 level of similarity) than to typical phytopathogenic bacteria of the E. carotovora group (with a 0.48 level of similarity). A phylogenetic analysis based on restriction polymorphisms of an amplified ribosomal DNA spacer region revealed that the avirulent strains studied here were different from all Erwinia, Klebsiella and other enterobacteria species strains. The AP PCR/hybridization technique showed cross homology of amplified DNA of these avirulent strains and a lack of such homology with the DNA from strains of other species. Numerical taxonomy data, rDNA analysis and AP PCR/hybridization assays confirmed that these avirulent bacteria may be regarded as an independent group of enterobacteria.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    ISSN: 1573-5036
    Keywords: canola ; oilseed rape ; root ; subsoil residual Zn ; wheat ; Zn loading ; Zn uptake
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract The residual effects of Zn supplied (+Zn: 1 mg kg−1 soil, -Zn: no Zn added) in subsoil to four oilseed rape genotypes (Zhongyou 821, Xinza 2 and Narendra: Brassica napus type, and CSIRO-1: Brassica juncea type) were studied on the following wheat in a glasshouse experiment in pots (100 cm long, 10.5 cm diameter). The topsoil (upper 20 cm soil in pots) was supplied with Zn (0.5 mg kg−1 soil) in all treatments whereas Zn (1 mg Zn kg−1 dry soil) was either supplied or omitted from the subsoil at time of sowing of oilseed rape genotypes. Oilseed rape plants were harvested at maturity and wheat (variety Songlen) was grown to evaluate the residual effects of subsoil Zn and oilseed rape genotypes. Subsoil residual Zn significantly improved the root growth, yield attributes, grain and straw yield of wheat. Wheat grain Zn concentration was 4 times higher in +Zn subsoil residual than under -Zn subsoil residual. Oilseed rape genotypes did not vary in their residual effect on grain and straw yield of wheat, but reflected a differential effect on Zn concentration and Zn content of wheat grain. Zinc uptake per wheat plant (grain + shoot + root Zn uptake) was about 4 times higher in +Zn subsoil residual than -Zn subsoil residual. Out of total Zn uptake per plant, 77%, 15% and 8% of Zn was loaded in wheat grains, shoots and roots respectively in +Zn subsoil residual. However in -Zn subsoil residual, distribution of Zn in grains, shoots and roots was 55%, 29% and 16% respectively. Zinc loading in grains of wheat was significantly higher in wheat grown after Narendra and Xinza 2 compared with wheat grown after Zhongyou 821 (Zn-inefficient genotype). These results indicate that subsoil residual Zn and Zn-efficient genotypes of oilseed rape have the potential to increase the Zn loading in wheat grains.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...