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  • Chemistry
  • Springer  (35)
  • Islamic Azad University, Science and Research Branch, Tehran, Fisheries  (13)
  • FISON  (11)
  • 1
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    The study and production of fish sauce from Caspian Sea lam fish with traditional fermentation method and microbe and enzyme adding method and identification of important bacteria (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19475 | 17408 | 2016-01-25 09:48:26 | 19475 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-06-29
    Beschreibung: Fish sauce is a popular fermented product used in south Asian countries which is made from different small fishes in this research work it was attempted to produce fish sauce from kilka of the Caspian sea, the fish sauce was made from three models of kilka ,such as whole kilka , cooked whole kilka and dressed kilka , each of these models treated it four different fashions of fermentation such as:1- Traditional method, 2- Enzymatic method 3- Microbial method, 4- Mixture of enzyme and microb The results of this investigation showed that time of fermentation for the traditional method was six month, enzymatic method one month, microbial method 3 month and the mixture of enzyme and microb 1 month. The rate of fermentation was least for dressed Kilka, microbial and biochemical changes of Kilka fish sauce were evaluated, total bacterial count was 2.1-6.15 log cfu/ml total volatile nitrogen (TVN) in samples recorded was 250 mg /100g, the amount of protein varied between 10-13 percent, the name of commercial enzymes added was Protamex and Flavourzyme, the bacteria added was L act ob acillus and Pediococous, fish sauce containers fish and 20% salt, temperature of keeping for fermentation was 37 degree c for 6 month.
    Beschreibung: PhD
    Beschreibung: Advisors: S. Moini Counsellors: A. keyvan, Gh. Vosoughi
    Schlagwort(e): Aquaculture ; Chemistry ; Fisheries
    Repository-Name: AquaDocs
    Materialart: thesis
    Format: application/pdf
    Format: application/pdf
    Format: 176
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  • 2
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    Proximate composition and amino acids profile of smoked catfish Clarias gariepinus and tilapia Oreochromis niloticus (2021)
    FISON | Lagos, Nigeria
    In:  http://aquaticcommons.org/id/eprint/23226 | 19325 | 2018-03-18 14:51:17 | 23226 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: The proximate composition and amino acids assay of smoked Clarias gariepinus and Oreochromis niloticus were determined using standard procedures. The mean proximate composition of Oreochromis niloticus are 8.9% moisture, 16.00% lipids, 5.6% ash, 44.5% crude protein, 0.42% crude fiber and 24.9% NFE while Clarias gariepinus has 8.19% moisture, 15.55% lipids, 4.725 ash, 40.46% crude protein, 0.50% crude fiber and 30.58% NFE. There is therefore a nutrient variation between the 2 species of fish Oreochromis niloticus has higher crude protein, lipids, moisture and ash content than Clarias gariepinus.The amino acids profile shows that both fishes have 17 amino acids. Apart from Tryptophan, the following essential amino acids Histidine, Methionine, Threonine, Isoleucine, Leucine, Lysine, Valine and Phenylalanine are present in both fish. Oreochromis niloticus however has higher quantities of the essential amino acids except for Histidine than Clarias gariepinus
    Beschreibung: Includes:- 2 tables.;2 figs.;7 refs.
    Schlagwort(e): Chemistry ; Fisheries ; Clarias gariepinus ; Oreochromis niloticus ; Nigeria ; Kainji L. ; freshwater environment ; Amino acids ; Ash content ; Lipids ; Organic compounds ; Moisture ; Proteins
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 91 - 95
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  • 3
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    Evaluations off heavy metals in fish from Lake Geriyo Yola, Nigeria using x-ray fluorescence technique (2021)
    FISON | Akure (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23338 | 19325 | 2018-04-07 17:17:18 | 23338 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-14
    Beschreibung: The evaluation of Cr. Cu, Mn, Fe, Ni, Zn,As and Pb concentrations in Clarias gariepinus and Oreochromis niloticus from Lake Geriyo Yola,Adamawa, Nigeria using X - ray fluorescence (XRF) technique is discussed. The analytical samples are irradiated with high energy electrons of 109Cd to produce fluorescent X-rays was produced which passes to the Silicon-lithium detector through Mo target as a source of monochromatic X-rays. The spectrum of energy generated on the detector was processed by a Multi- Channel Analyzer to obtain analytical data. The intensity of the fluorescent X-rays on the detector is proportional to the concentration of the individual element of interest in the sample. This method can identify up to 30 or more elements at the same time. The results showed varying levels of heavy metals in the fishes. The concentrations of Cr, Mn, Cu, and Ni in the fishes were much higher than WHO and PEPA maximum permissible limits, while the concentrations of Zn and Pb were lower than the standards. The results suggest that the lake is polluted with Cr, Mn, Cu and Ni and the consumption of fishes of the lake is life threatening to man.
    Beschreibung: Includes:- 1table.;11 refs.
    Schlagwort(e): Ecology ; Chemistry ; Pollution ; Clarias gariepinus ; Oreochromis niloticus ; Nigeria ; Geriyo L. ; freshwater environment ; Heavy metals ; Fish ; X-ray fluorescence analysis ; Pollution ; Pollution effects
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 69-71
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  • 4
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    Effects of salinity on larval dimension of Tilapia guineensis (2021)
    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23422 | 19325 | 2018-04-25 19:24:46 | 23422 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-14
    Beschreibung: Tilapia guineensis eggs were spawned and hatched in different salinities (17, 12, 7, 5, 2 and 0) ppt. The study was conducted in eight replicates. The aim of the investigation was to ascertain disparity in hatching size of Tilapia guineensis attributable to salinity. Immediately hatching was observed, body weight of five hatchlings in each replicate was individually weighed in milligramme. The individual total length of the five hatchlings was also measured in millimeter. The height of the yolk sac larva was determined with micro-metre screw gauge graduated in millimeter from the top of the yolk sac to the dorsal region of the larva. Data obtained were used to calculate yolk sac volume. Significant differences (P〈0.01) were observed in body weight and total length of larvae hatched in different salinities. The heaviest and longest larvae were hatched in 12 ppt saline water. The yolk sac volume of larvae hatched in lower salinities were significantly higher (P〈0.01) than the yolk sac volume of larvae hatched in higher salinities. The smallest yolk sac volume was recorded in 12ppt saline water. Our findings show that salinity could be manipulated for economic production of heavier seeds of Tilapia.
    Beschreibung: Includes:- 5 tables.;6 refs.
    Schlagwort(e): Aquaculture ; Chemistry ; Tilapia guineensis ; Nigeria ; brackishwater environment ; Salinity effects ; Larvae
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 51-55
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  • 5
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    Physico-chemical parameters of fish ponds as it affects fish production in Ado-Ekiti, Ekiti State, Nigeria (2021)
    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24590 | 19325 | 2018-05-20 16:05:58 | 24590 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-15
    Beschreibung: The water analysis of five selected ponds in Ado-Ekiti in Ekiti State, was carried out to determine their suitability for fish culture. Pa rameters analyzed were: Temperature, Turbidity, Carbon (IV) oxide, Alkalinity, Hardness, pH and Dissolved oxygen. Values for temperature ranged between 20.0~'C and 29.0~'C, Turbidity values were between 46.0-50.2cm, Carbon (IV) oxide: 11.5-12.2mg/litre; alkalinity: 100-120mg/liter; hardness: 110-200mg/litre; pH: 6.8-7.8 and dissolved oxygen: 5.8-6.8mg/liter. The values obtained were found to be within acceptable range for fish production.
    Beschreibung: Includes: 10 references.
    Schlagwort(e): Aquaculture ; Chemistry ; Nigeria ; Physico-chemical parameter ; Fish pond ; Ado-Ekiti ; Fish production ; freshwater environment ; automation
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 97-100
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  • 6
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    Identification and measurement of fatty acids, amino acids in roe of tuna fish (Thunnus tonggol) and its TVB and peroxide value during cold storage (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19311 | 17408 | 2016-02-08 10:25:26 | 19311 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-06-25
    Beschreibung: The first aim of this research was to identify fatty acids, amino acids composition of Thunnustonggol roe and their changes during cold storage (-18'C). The second aim was to determinethe changes of moisture, protein, fat and ash contents of the roe during one year cold storage(-18'C). 60 samples of longtail tuna (Thunnus tonggol) ovaries were randomly collected formBandar-e-Abbas landings. The samples were frozen at-30'C and kept in cold store at -18'Cfor one year. According to a time table, the samples were examined for identification offatty acids, amino acids, moisture, protein, fat, ash, peroxide and T.V.N. and their changeswere evaluated during this time. The results showed that 26 fatty acids were identified. Theunsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 62.33 and 37.6%,respectively, in fresh roe. So that, DHA (C22:6) and oleic acid (C18:1) had high amounts(24.79 and 21.88%) among the UFA and palmitic acid (C16:0) was the most content(22.75%) among the SFA. The PUFA/SFA was 0.91. Also, 17 amino acids were identifiedthat essential amino acids (EAA) and nonessential amino acids (NE) were 10478 and 7562mg/100g, respectively, and E/NE was 1.38. Among the EAA and NE, lysine (2110mg/100g)and aspartic acid (1924 mg/100g) were the most contents. Also, results showed that moisture,ash, protein and fat contents were 72.74, 1.8, 19.88 and 4.53%, respectively, in fresh roe. Theeffects of freezing and cold storage on the roes showed that UFA and SFA contents havereached to 49.83 and 48.07%, respectively, at the end of cold storage. It indicated that thesecompounds change to each other during frozen storage. Also, n-3 and n-6 series of fattyacids were 32.75 and 1.61% in fresh roe. But their contents decreased to 22.96 and 1.25% atthe end of period. Among the fatty acids, 22:6 and C16:0 had the most changes. The changesof fatty acids were significantly at 95% level except for C15:1, C18:3(n-3) and C20:4(n-6).All of the amino acids decreased in frozen storage and their changes were significantly(P〈0.05). EAA was 7818 mg/100g and E/NE was 1.27 at the end of storage period. Amongthe amino acids, leucine and lysine had the most changes. Moisture, ash, protein and fatcontents were 70.13, 1.82, 19.4 and 6.51%, respectively, at the end of storage period. Theperoxide value and T.V.N. increased during storage. So that, their contents have reached to5.86 mg/kg and 26.37 mg/100 g, respectively, at the end of frozen storage. The best shelf lifeof Thunnus tonggol roe was 6 or 7 months, because of lipid oxidation and increasing ofperoxide.
    Beschreibung: PhD
    Beschreibung: Advisors: S. Moeini Counsellors: A. Keyvan, M. Yousefian
    Schlagwort(e): Biology ; Chemistry ; Fisheries
    Repository-Name: AquaDocs
    Materialart: thesis
    Format: application/pdf
    Format: application/pdf
    Format: 213
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  • 7
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    Effect of Terminalia suparba on fecundity and latency period of Clarias gariepinus broodstocks (2021)
    FISON | Minna (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24067 | 19325 | 2018-05-10 10:15:21 | 24067 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-15
    Beschreibung: This study focused on the assessment of Terminalia suparba (bark, leave and root) based diet to improve the ovulation of Clarias gariepinus brood stocks. Ten female and ten male brood stocks were obtained from a reputable fishfarm in Ogun State, Nigeria and were fed with the diets for four weeks before the breeding exercise. The latency period observed in treatments 1 to 4 was 4hours 30minutes while the ovulation period in treatment 5 was 8 hours. There was no significant different (P〉0.05) among the means. The brood stocks in Treatment 2 (Root) has the highest fecundity count (2001) while those in Treatment 5 (control) has the least fecundity count (1496). The phytochemical analysis of the plant materials showed the presence of Alkaloids, Tannin, Phenol, Glycoside, Flavonoids, Steroids, Phlobatannin, Saponin, Anthraquinones. The physical and chemical parameters of water observed showed that dissolved oxygen value ranges from 3.28 -4.60, pH 6.5 - 8.5, temperature 28.0 - 28.8 and conductivity 8.9 - 9.20. It is therefore concluded that the inclusion of Terminalia suparba in the feed of Clarias gariepinus broodstock will not only improve ovulation but also reduce the latency period.
    Beschreibung: Includes: 5 tables;Also includes: 11 refs.
    Schlagwort(e): Aquaculture ; Chemistry ; Ecology ; Clarias gariepinus ; Nigeria ; broodstocks ; Terminalia specie ; Latency ; fecundity ; Clarias gariepinus ; freshwater environment ; Artificial feeding ; Feeding experiments ; Fecundity ; Brood stocks ; Sublimation heat ; Ovulation ; Physicochemical properties ; Fish culture
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 5-10
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  • 8
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    Survey of physical characteristics of the upper reaches of new Calabar River, Niger Delta, Nigeria (2021)
    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24618 | 19325 | 2018-05-22 06:12:36 | 24618 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-15
    Beschreibung: One of the priority research projects of the Nigerian Institute for Oceanography and Marine Research (NIOMR) is broodstock development and mass propagation of silver catfish, Chrysichthys nigrodigitatus of which the broodstock is naturally abundant in New Gala River. Selected physical characteristics and water physico-chemical parameters of the upper reach of the New Calabar River at Aluu were investigated. The highest depth value of 9.20 m was recorded in the middle of the river. The width of the river measured during spring high tide and low tide were 174 m and 110 m respectively. The cross-sectional area and average flow velocity of the river were 797.13 m2 and 0.374 m/s respectively. The discharge of the river was computed as 298.13m3/s. The river water was acidic most of the period (Hydrogen ion concentration, pH: 5.12 to 7.43), with low total alkalinity values (4.00 to 12.00 mgCaCO3/L) and low total hardness values (11.5 to 51.2 mgCaCO3/L) which indicate that the river water is black and soft. There was significant (p~,0.05) seasonal variation in temperature (23.1 to 31.7~'C\}, Secchi transparency (9.30 to 19.00 cm), total hardness (11.5 to 51.2 mgCaCO3/L), dissolved oxygen (5.20 to 7.50 mg/L) and dissolved oxygen deficit (0.02 to 2.95mg/L). These results are useful for several stake holders who use the river as a sink for trade wastes, as source of water for fish farming, as source of broodstocks of Chrysichthys nigrodigitatus, as raw water for water treatment plants, and as means of transportation of industrial materials.
    Beschreibung: Includes: 16 references.
    Schlagwort(e): Chemistry ; Fisheries ; Limnology ; Chrysichthys nigrodigitatus ; Nigeria ; New Calabar River ; New calabar River ; Physical characteristics and physico-chemical features ; Seasonal variation ; freshwater environment ; automation
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 206-210
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  • 9
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    Physico-chemical parameters in relation to fish production of Dadin Kowa Dam, Gombe State, Nigeria (2021)
    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24619 | 19325 | 2018-05-22 06:14:16 | 24619 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-15
    Beschreibung: Eight month physicochemical study of Dadin Kowa Dam was carried out forthnightly from July, 2011 to february 2012. Air temperature ranged from 18.25~'C ~c 28~'C ~c 0.50 to 28~'C ~c 2.16. Water tmperature ranged from 18.75~'C ~c 2.21. Transparency ranged from 11.00cm ~c 1.83 to 29.63 cm ~c ~c 2.14. Conductivity ranged from 13.00~Ks/cm ~c 13.33 to 41.38~Ks/cm ~c 5.54. Hydrogen ion (pH) ranged from 6.69 ~c 1.03 to 8.39 ~c 1.17. Dissolved oxygen ranged from 6.39mg/l ~c 1.03 to 10.14mg/l ~c 1.17. Total alkalinity ranged from o.69mg/l ~c 0.38 1.34mb/l ~c 0.02. Total ammonia ranged from 0.20mg/l ~c 0.027 to 0.83mg/l ~c 0.05. There were various levels of correlation between these parameters. There was no significant difference between both sites and months (p〉0.05) of all the parameters except total nitrogen which show a significant difference between the sites (p〈0.05) and transparency also shows a significance between the months (p〈0.05). All physicochemical parameters were almost within the tolerable limits for supporting aquatic life.
    Beschreibung: Includes: 27 references.
    Schlagwort(e): Fisheries ; Chemistry ; Nigeria ; Dadin Kowa Dam ; Physico-chemical parameters ; Fish production ; Dadin Kowa Dam ; freshwater environment ; automation
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 211-213
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  • 10
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    Study on the sustainability of FPC produced from Kilka (Clupeonella engrauliformis, C. grimmi and C. cultriventris) in two vacuum packaging and modified atmosphere packaging at different environmental factors (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19301 | 17408 | 2016-02-01 21:14:27 | 19301 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-14
    Beschreibung: Fish protein concentrate (FPC) is a healthy, sustainable and high nutritiveproduct which sanitized produced from fishes in which, protein and othernutrients are more concentrated than in fresh fishes.The aim of this research is to study on the sustainability of FPC producedfrom Kilka (Clupeonella engrauliformis , C. grimmi and C. cultriventris)in two Vaccum Packaging and Modified Atmosphere Packaging atdifferent environmental factors during six months.In our study the analysis of FPC protein showed 91.2%, lipid: 0.5%, ash:3.6%, moisture: 2.3%, Total Volatile Nitrogen: 10 ml/100gr andperoxide: 5meq/kg. Amino acids and fatty acids were also determined.Bacteria and Fungi were lower than 1000 colony. Samples are kept indifferent condition of temperature (5, 20 and 35 degree centigrade),humidity (25, 40 and 90 percent) and light and dark environment in sixmonth.Lipid rate in FPC after 6 months in VP and MAP (60% C02, 30 % N2 and10% O2), packages was decreased but was not significant (P〉0.05). It wasalso detected that increase temperature lead to more decrease in lipidcontent. Protein rate of FPC was decreased from 91.2% to 73.6% duringsix months at 35°C in VP Package and from 91.2% to 69.4% in MAPpackage. These changes were significant (P〈0.05). TVN and PV rate inFPC after 6 months in VP and MAP packages was increased but wassignificant (P〈0.05). Amino acids and fatty acids were also determined.But more changes in MAP packages was detected.
    Beschreibung: PhD
    Beschreibung: Advisors: Abbas Ali Motalebi Counsellors: Wadud Rzvylar, Aliasghar Khanipoor. The full text document is in Farsi only so it has not been possible for AC Editors to check the metadata input.
    Schlagwort(e): Chemistry ; Fisheries
    Repository-Name: AquaDocs
    Materialart: thesis
    Format: application/pdf
    Format: application/pdf
    Format: 193
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  • 11
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    Quantative and qualitive identification of the fatty acids in the mullet (Liza aurata), sever juga (Acipenser stellatus) and Persian sturgeon (A. persicus), considering of cold storing effects on them (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19474 | 17408 | 2016-01-25 09:45:47 | 19474 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-06-29
    Beschreibung: At the fishing season, in 2000, samples of species persian sturgeon (A. persicus), Severjuga (A. stellatus) and Mullet (L. aurata), were caught from the southern coasts of Caspian Sea and were freezes and preserved in the cold storage for one year They have also become biometery. The tissue's fillet were identified in order to determined the Fatty Acids. This was done during one year, frequently, fresh, two weeks after freezing and then monthly, respectively. So, after the extraction of lipids from the tissues and methylation, was injected to the gas-liquid Chromatography. After calibration, identified Fatty Acids were compared with standards according to their Retention Times. Peroxid value, lipid content and humidity were controlled. The unsaturated Fatty acids had The most amount, and a plenty of Polyunsaturated Fatty acids (PUFA) were observed, so that linoleic (C18:2), a-linolenic (C18:3), Arashidonic (C20:4), EPA (C20:5) and DHA (C22:6) Fatty acids had high amounts. The w-3, PUFA were more in comparison with w-6. The effects of freezing and cold storing on the fish fatty acids , were evaluated by the statistical tests , like SPSS, Tukey, Homogenous and Anova, and showed that in some species, a group of Fatty acids, specially PUFA, had some variation. The peroxide value that indicates the lipid deterioration, increased during toring. So, the best term if preserving in the cold storage, were determined and their Nutrition value and Medical applications due to their consumption were investigated.
    Beschreibung: PhD
    Beschreibung: Advisors: Sohrab Moeini Counsellors: Amin Keyvan, Mehdi Yousefian
    Schlagwort(e): Chemistry ; Fisheries
    Repository-Name: AquaDocs
    Materialart: thesis
    Format: application/pdf
    Format: application/pdf
    Format: 163
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  • 12
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    Physico-chemical and bacteriological investigation of fish and water in Aiba reservoir, Iwo (2021)
    FISON | Akure (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23326 | 19325 | 2018-04-06 16:03:20 | 23326 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-14
    Beschreibung: This study looked into the physicochemical and bacteriological investigation of fish and water in Aiba Reservoir. Water and fish samples collected were studied to assess their bacteriological and physicochemical characteristics and their suitability for domestic purposes. Structural questionnaires were administered to the fishermen around the reservoir and experiments were carried out in the laboratory to analyze the samples. The results showed that the total viable bacteria count was high(1.02 x 105 cfu/ml) while few Staphylococcus aureus and E. coli occurred insignificantly. The population of S. aureus and E. coli in the fish gills, liver and tissue were insignificant. The results obtained from the physicochemical analysis of the water samples showed that the reservoir has optimum water temperature of 29degreesC ~c 0.25, a pH of 7.70 ~c 0.20, dissolved Oxygen level of 7.20mgO2/1 ~c 0.20 and total hardness of 45.00 mg/ICaC03 ~c 1.05. The microbial load in the fish sample is higher than that in the water sample. Further strict hygienic measures and surveillance is recommended so as to improve the water quality and to avoid deleterious effects on the health of the Iwo inhabitants and its neighboring communities who also benefit from the reservoir.
    Beschreibung: Includes:- 2 figs.;11 refs.
    Schlagwort(e): Chemistry ; Fisheries ; Nigeria ; Aiba Reservoir ; freshwater environment ; Physicochemical properties ; Bacteriology ; Water quality ; Water ; Bacterial counters
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
    Format: application/pdf
    Format: application/pdf
    Format: 25-28
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  • 13
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    Primary production and physico-chemical parameters of a freshwater fish farm in the south east Nigeria (2021)
    FISON | Akure (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23410 | 19325 | 2018-04-12 09:04:25 | 23410 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-14
    Beschreibung: Comparative primary production in Little Stream Farms, near Uyo was investigated in relation to physico-chemical parameters of the adjacent perennial stream and the fish ponds. Except for temperature, which showed the same values for both stations, physico-chemical variables generally showed significant difference (P〈O.05) between the pond water and the adjacent stream. Values of silicates, Turbidity (NTU), Secchi Disc Transparency and Total Suspended Solids (TSS) exhibited significantly variable trends (P〈O.05), especially in the stream water, in response to the commercial sand dredging activities upstream from the fann location. Lowest value of stream transparency (O.1M) recorded was during the peak of the sand dredging, whereas the stream water showed absolute transparency in the absence of the dredging. The water quality parameters also exhibited a general trend of significant seasonal variation (P〈O.05). Five phytoplankton families: Bacillariophyceae, Chlorophyceae, Cyanobacteria, Euglenophyceae and Dinophyceae occurred in the ponds, while three families, Bacillariophyceae, Chlorophyceae and Cyanobacteria occurred in the stream. Bacillariophyceae showed the highest relative abundance in both stations A and B.
    Beschreibung: Includes:- 1 table.;3 figs.;11 refs.
    Schlagwort(e): Aquaculture ; Chemistry ; Ecology ; Nigeria ; Akwa Ibom State ; freshwater environment ; Physicochemical properties ; Freshwater ecology ; Water quality ; Phytoplankton ; Suspended particulate matter
    Repository-Name: AquaDocs
    Materialart: conference_item , TRUE
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  • 14
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    Assessment of water quality parameters in Lake Alau (2021)
    FISON | Akure (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/23404 | 19325 | 2018-04-12 08:55:07 | 23404 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-14
    Beschreibung: The physico-chemical parameters of Lake Alau were monitored for four months to assess the water quality. Parameters such as temperature, transparency, conductivity, dissolved oxygen, biochemical oxygen demand, Ca, P, etc were studied in five stations (A, B, C, D and E). Water samples were collected monthly from 8:00 to l2:00noon, for four months (July - October 2008, wet season) and analysed. The physico-chemical parameters were within the ranges of unpolluted water bodies. Variation occurs in almost all the months of the study. Significant difference (P〈0.05) occurred in pH, transparency and Ca among the stations, and insignificant difference (P〉0.05) in temperature, conductivity, dissolved oxygen, biochemical oxygen demand, Mg and P. These variations may be due to effects of fertilizer application, herbicides and insecticides in irrigated farms around the Lake.
    Beschreibung: Includes:- 2 tables.;24 refs.
    Schlagwort(e): Chemistry ; Limnology ; Nigeria ; Alau L. ; freshwater environment ; Physicochemical properties ; Water quality ; Temperature ; Turbidity ; Transparency ; Dissolved oxygen
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  • 15
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    Preliminary studies on some physico-chemical parameters and fish species composition of Doma Dam, Nasarawa State, Nigeria (2021)
    FISON | Lagos (Nigeria)
    In:  http://aquaticcommons.org/id/eprint/24638 | 19325 | 2018-05-24 09:36:38 | 24638 | Fisheries Society of Nigeria
    Details
    Publikationsdatum: 2021-07-15
    Beschreibung: Study of some Physico-chemical parameters and fish species composition of Doma Darn was carried out between the month of August 2012. Fishing communities along the dam were selected at sampling stations and collection of fish species. The values of physico-parameters obtained for stations were in the range of 28.10-92 m for depth, 27.70-28.48~'for temperature, 7.03-7.64 for PH, 7.23-7.64mg/l for dissolved oxygen (DO), 30.08-31.75 ntu for turbidity, 94.64-105.17mg/l for alkalinity and 79.17-80.58mg/l for total hardness. The result indicated that there was significant difference (p〈0.5)for depth, temperature turbidity and alkalinity, while there was no significant difference (p〈0.05) for DO, pH and water hardness among the stations. The result of these parameters among the duration shows that there was significant different (p〈0.05) in all the parameters except pH. The study revealed that there were twenty-five (25) fish species belonging to 12 families in the dam. The family Cichlidae and Mochokidae and Bagridae which has three each, While the family, Polypteridae, Channidae, Centropomidae, flepsetidae and Protopteridae has the lowest number of one (1) each. The overall result revealed that the Phvsico-chemical parameters were mostly influenced by duration and not much by stations; and parametersoaram measured were within the recommended water quality requirement for growth and survival of aquatic organisms.
    Beschreibung: Includes: 10 references.
    Schlagwort(e): Chemistry ; Fisheries ; Nigeria ; Doma Dam ; Doma Dam ; Fishing community ; Physico-chemical parameter ; Fish species ; freshwater environment ; automation
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    Materialart: conference_item , TRUE
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    Format: 295-297
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  • 16
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    Application of whey protein incorporation with Cinnamon oil as a preservative in Huse huso fillet under chilled storage condition (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19139 | 17408 | 2016-02-06 09:39:39 | 19139 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: Biodegradable protein-based film was developed by incorporating cinnamon essential oil(CEO) into whey protein concentrate (WPC) at level of 0.8% and 1.5% v/v. Then physicaland mechanical properties of the films were evaluated. Adding CEO to the WPC matrixdecreased the water vapour permeability of the films and water solubility. Films containingCEO showed significant antibacterial activity both gram-positive and gram-negative strainsand exhibited significant inhibitory effect on the studied fungi. In continue, the effect ofwhey coating and whey coating incorporated with 1.5% CEO on quality and shelf life ofHuso huso fillet during refregrated (4±1°C) storage period were also investigated. The controland treated fish samples were analyzed for microbiological (total viable count, psychrophiliccounts), chemical (PV, TBA, FFA, pH, TVB-N), and sensory characteristics in 4-dayintervals up of microbial, chmical and sensoy analyses indicated lower levels of PV, TBA,FFA, pH, TVB-N in coasted sampels and specially, those with CEO while were kept inrefrigerator. Based on results, whey protein edible coating contain 1.5% cinnamon essentialoil could enhance preserving ability Huso huso during storage cold.
    Beschreibung: PhD
    Beschreibung: Advisors: M. Rezaei Counsellors: M. Soltioni, A. kamali
    Schlagwort(e): Chemistry ; Fisheries
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    Materialart: thesis
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  • 17
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    A study on the effect of Zataria multiflora Bioss essential oil and Nisin on the growth of Lactococcus garvieae in the rainbow trout fillet (Oncorhynchus mykiss) (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19143 | 17408 | 2016-02-06 09:45:48 | 19143 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: The ever-increasing population of the world and the growing need for animal protein has doubled the modern man’s demand for food. Additionally, the improvement in the general public health, and the worsening of environmental/ecological pollution have prompted today’s world to look for ways to procure healthy food. And one such attempt is the use of natural preservatives to decrease the bacterial load in foodstuffs, in other words, to increase their durability.This study evaluates the effects of different concentrations of Zataria multiflora Bioss (EO 0, 0.005, 0.015, 0.045, 0.135, 0.405%) and Nisin (0, 0.25, 0.5, 0.75 μg/ml) and storage time (9 days) on the growth of Lactococcus garvieae Ir-170A(856bp) alone, and their combination in a food model system (fillets of the rainbow trout (Oncorhynchus mykiss). Additionally, the growth of a sample of this bacteria in laboratory conditions was studied.The results of this study showed that different concentrations of Nisin had a significant impact (p〈0.05) on Lactococcus garvieae.With the value of t in 0.75 μg/ml, the effectiveness rose to 65.77%; the biggest effect on Lactococcus garvieae. And the effect at 4 0C exceeded 80C.The study has also demonstrated that all concentrations of Zataria multiflora Bioss were effective against Lactococcus garvieae. However, with the value of t at 0.405%, the effectiveness was 71.91%. This value had the biggest effect on Lactococcus garvieae. At 4 0C, the effect surpassed the one at 80C.The synergistic effects of the EO and Nisin showed that with the value of t at 0.405% EO and 0.75 μg/ml Nisin was 14.62% had the greatest effect on Lactococcus garvieae.In this study, multi-factorial effects for different concentrations of Zataria multiflora Bioss (EO 0, 0.005, 0.015, 0.0025%), three different concentrations of122Nisin (0, 0.25,0.75 μg/ml) and two different levels of PH (5.5 , 7) at two incubation temperatures (15,37) on logp% of Lactococcus garvieae during 43 days in BHI broth were evaluated. Most of the effects on Lactococcus garvieae occurred in PH 5.5 and at a temperature of 150C.
    Beschreibung: PhD
    Beschreibung: Advisors: Mehdi Soltani, A. Akhondzadeh Basti. counsellor: A. Kamali
    Schlagwort(e): Aquaculture ; Chemistry ; Fisheries
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  • 18
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    Influence of cold storage time on the protein changes and fatty acids deterioration of (Rutilus frisi kutum) during frozen storage (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19304 | 17408 | 2016-02-08 10:30:38 | 19304 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-14
    Beschreibung: The main aim of this research was to identify fatty acids composition of Caspian sea of White fish Rutilus frisi kutum tissue and their changes during one year cold storage (-18Ċ).The secondary aim was to determine the changes of moisture, ash, protein, fat, and to investigate the effects of storage time on peroxide, TBAi, FFA, and extractability of myofibrillar proteins of the fish tissue during one year cold storage (-18 Ċ). 10 samples of (Rutilus frisi kutum) were randomly collected from Anzali landings. The samples were frozen at -30 Ċ and kept in cold storage at -18Ċ for one year. According to time table, the samples were examined. The results showed that 27 fatty acids were identified. The unsaturated fatty acids (UFA) and saturated fatty acids (SFA) were 74/09 and 21/63 %, respectively, in fresh tissue. So that DHA (C22:6) oleic acid (C18:1c) had high amounts (15/07 ,20/57 ) among the UFA and palmitic acid (C16:0) was the most (13/09 %) among the SFA. The effects of freezing and cold storage on fish tissue showed that UFA and SFA contents have reached to 58/79 and 22/17 %, respectively, at the end of cold storage. It indicated that these compound change to each other during frozen storage. Also ω-3 and ω-6 series of fatty acids was 24/22 and 15/56% in fresh tissue, but their contents decreased to 8/68 and 5/11% at the end of period. Among the fatty acids C22:6, C18:1c and C16:0 had the most changes. The changes of fatty acids were significantly at 95% level expected for C18:0. Results showed that moisture, ash, protein, and fat contents were 75/9±0/03, 1/28±0/012, 21/8±0/2, and 4/1±0/01 % respectively, in fresh tissue. The moisture, ash, protein, and fat contents were 72/3±0/04, 1/83±0/05, 1/91±0/01 and 19/9±0/01 % respectively, at the end of storage period. Lipid damage was measured on the basis of free fatty acids (FFA), peroxide value (PV), and Thiobarbituric acid index (TBA-i). PV, TBARS and FFA concentration of frozen Caspian Sea white fish stored at -18 Ċ the temporal variation of these three variables were statistically significant (p〈0.001). Results of White fish myofibrillar proteins showed aggregation of bound reduced for stored at 12 months. SDS-PAGE analysis revealed that, the intensity of the myosin heavy chain and actin bound was reduced with increasing storage time. SDS-PAGE patterns showed that myosin heavy chain was much more susceptible to hydrolysis than actin.Key words: Rutilus frisi kutum, frozen storage, ω-3, ω-6, protein myofibrillar
    Beschreibung: PhD
    Beschreibung: Advisors: Sohrab Moeini, Nasser Ghaemi Counsellors: A.K. Haghdost
    Schlagwort(e): Chemistry ; Fisheries
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  • 19
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    Application of combined effect of sodium acetate and nisin on reduction of contamination by Listeria monocytogenes in vacuum packaged grass carp (Ctenopharyngodon idella) fillets kept at 4°C (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19186 | 17408 | 2016-02-06 09:46:24 | 19186 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: In this study microbiological , chemical quality and fatty acid composition ofgrass carp (Ctenopharyngodon idella) fillets treated by dipping in sodiumacetate (%1 and %3), nisin (% 0.1 and % 0.2) and combination of sodiumacetate and nisin was evaluated during 16 days of refrigerated of 4°CAntilisterial effect of nisin was enhanced with the increased concentration ofsodium acetate. At day 12 post storage, Listeria monocytogenese count washigher in the control group than the recommended value, however in sodiumacetate and nisin treated samples, the count was lower (5.17-5.91 log cfu/g).With increasing the concentrations of sodium acetate, mesophilic counts werelower. Regarding nisin, better results was obtained by applying %0.1 nisin.Greater inhibition of mesophile bacteria was observed when combinationtreatment was used. The number of lactobacillus was lower when higherconcentrations of sodium acetate and nisin were used.Total Volatile Nitrogen values at the end of the experiment were lower in thesamples treated with both nisin and sodium acetate and the better results wereobtained in combination treatments. Peroxide (PV) at the end of the experimentwas 1.9 meq/kg in control, and the lowest values were observed for thetreatments 3(%0 sodium acetate +% 0.2 nisin) and 9(%3 sodium acetate +% 0.2nisin) between 1.08 and 1.62 meq/kg without significant difference.Thiobarbituric acid (TBA) levels at the end of experiment have been shown tobe 0.46 mg malonaldehyde per kg in the control. On the other hand treatments 9had the TBA values of 0.19 mg malonaldehyde per kg which was significantlylower than that of control.Polyunsaturated fatty acids increased by increasing the sodium acetate dosesand instead saturated fatty acids and n-6/n-3 ratio decreased. The ratio ofUFA/SFA and also C22:6/C16:0 increased when a higher concentration ofsodium acetate has been used. The best result obtained by using 3% of sodiumacetate but no such relation with nisin was observed.
    Beschreibung: PhD
    Beschreibung: Advisors: Mehdi Soltani, Abolghasem Kamali Counsellors: Mohammad Reza Ghomi, Seyed Ebrahim Hoseini
    Schlagwort(e): Chemistry ; Fisheries
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  • 20
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    Effect of thawing methods on the chemical, biochemical, microbiological and sensory indices of Caspian Sea kutum (Rutilus frisii kutum) and rainbow trout (Oncorhynchus mykiss) (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19182 | 17408 | 2016-02-06 09:57:11 | 19182 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: Effects of different thawing method i.e. in a refrigerator, in water, at air ambient temperature and in a microwave oven on proximate, chemical (PV, TBA, FFA, TVB-N, SSP, FA), biochemical (pH, WHC,ThL), microbial (total viable, psychrotrophic, coliform, Shewanella and yeast-mould count) and sensory analysis were carried out on frozen whole Caspian sea Kutum (Rutilus frisii kutum) and Rainbow trout (Oncorhynchus mykiss) carcasses. The values of ash, protein, SSP, WHC, PUFA, PUFA/SFA. EPA+DHA/C16:0, pH, and microbial count of thawed samples decreased significantly while fat, PV, TBA, FFA, TVB-N, SFA and MUFA increased compared to the fresh fish (unfrozen) as control samples. Also, sensory evaluation all of thawed samples showed a significant (p〈0.05) quality loss compared to the fresh fish as control samples. The lowest chemical and biochemical values as well as microbial growth were determined in water thawed samples. Therefore, based on this study thawing in water is most suitable for frozen whole rainbow trout.
    Beschreibung: PhD
    Beschreibung: Advisors: Masoud Rezaei, Mehdi Soltani Counsellors: Mohammad Haghighi, Reza Pourgholam
    Schlagwort(e): Aquaculture ; Biology ; Chemistry
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  • 21
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    Effects of Zataria multiflora Boiss essential oil and nisin on the growth of Staphylococcus aureus in light salted silver carp fillet (Hypophthalmichthys molitrix) (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19245 | 17408 | 2016-02-08 10:18:48 | 19245 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: There is an increasing demand in developing newer and safer methods in preserving food products.Among which herbal additives seem to attract evermore attention recently.the major advantage of herbal additives is due to their favorable aroma besides their antimicrobial effects and less expensive than chemical additives. Zataria multiflora Boiss is a native Iranian herb which is used vastly as a food preserver essential oils and also medical usage.Metabolites of harmless bacteria, such as Nisin are also known to be safe preservatives that have antimicrobial activity.However to establish the usefulness of natural antimicrobial preservatives, they must be evaluated alone and in combination with other preservation factors to determine whether there are synergistic effects in rigid media .In this study were evaluated the effects of different concentrations of Zataria multiflora (EO 0, 0.005, 0.015, 0.045, 0.135, 0.405 ,0.810 %) and Nisin(0, 0.15, 0.25, 0.75 μg/ml) and Storage time (up to 21 days) on growth of Staphylococcus aureus ATCC 6538 in a food model system(light salted fish of silver carp, Hypophthalmichthys molitrix).The results on growth of S. aureus were evaluated using SPSS 15.0 statistical software (SPSS 15.0 for windows, SPSS Inc.) and analyzed the logarithm of total count of the bacteria by Tukey Test. Results were considered statistically significant when P≤0.05.The growth of Staphylococcus aureus was affected significantly(P〈0.05) by EO and Nisin and also combinations of EO and Nisin.Samples treated with 0.135, 0.405 and 0.810% of thyme essential oil showed a significant decrease on the growth of the bacteria compared with an treated samples(P〈0.05). No significant difference was seen on the growth of S.aureus in samples treated with lower concentrations of Z.multiflora(below 0.045%) and untreated group(P〉0.05).The most inhibitory effects were seen in samples treated with 0.405% and 0.810% of thyme essential oil until 9 and 12 days after storage,respectively.Also there was significant inhibtory effect(P〈0.05) in different concentration of nisin on the organism compared with an treated samples.The synergism effects of the Eo and nisin on the growth rate of the bacteria was significant (P〈0.05) compared with untreated samples and samples treated with the Eo or nisin, only. Synergismic effects was observed at concentration of 0.405 and 0.810% of Z. multiflora essential oil with 0.25 μg/ml Nisin, respectively until 15 days after storage.As expected it is preferred to apply the least possible amounts of additives in food preserving that not only are effective and safe but are economically justifiable.
    Beschreibung: PhD
    Beschreibung: Advisors: Afshin Akhondzadeh Basti, Mehdi Soltani counsellors: Abbas Matinfar
    Schlagwort(e): Aquaculture ; Chemistry ; Fisheries
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  • 22
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    Determination of proximate composition, shelf life and fatty acid profiles of breaded kilka (Clupeonella cultriventris) during frozen storage (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19144 | 17408 | 2016-02-06 09:40:52 | 19144 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: The present study aimed production of a new product with various texture and sensoryproperties in chase of the impetus for increasing human consumption considering suitableresources of Kilka fish in Caspian Sea. Following deheading, gutting, and brining, commonKilka were battered in two different formulations, i.e. simple batter and tempura batter, viaautomated predusting machinery and then, they were fried through flash frying for 30 secondsat 170°C in sunflower oil after they were breaded with bread crumbs flour. The products weresubjected to continuous freezing at -40°C and were kept at -18°C in cold storage for fourmonths once they were packed. Chemical composition (protein, fat, moisture, and ash), fattyacid profiles (29 fatty acids), chemical indices of spoilage (peroxide value, thiobarbituric acid,free fatty acids, and volatile nitrogen), and microbial properties (total bacteria count andcoliform count) were compared in fresh and breaded Kilka at various times before frying (rawbreaded Kilka), after frying (zero-phase), and in various months of frozen storage (phases 1,2, 3, and 4). Organoleptic properties of breaded Kilka (i.e. odor, taste, texture, crispiness,cohesiveness of batter) and general acceptability in the phases 0, 1, 2, 3, and 4 were evaluated.The results obtained from chemical composition and fatty acid profiles in common Kilkadenoted that MUFA, PUFA, and SFA were estimated to be 36.96, 32.85, and 29.12 g / 100glipid, respectively. Levels of ù-3 and ù-6 were 7.6 and 1.12 g / 100 gr lipid, respectively.Docosahexaonoic acid (20.79%) was the highest fatty acid in PUFA group. ù-3/ù-6 andPUFA/SFA ratios were 7.6 and 1.12, respectively. The high rates of the indices and highpercentage of ù-3 fatty acid in common Kilka showed that the fish can be considered asinvaluable nutritional and fishery resources and commonsensical consumption of the speciesmay reduce the risk of cardiovascular diseases. Frying breaded Kilka affected overall fat andmoisture contents so that moisture content in fried breaded Kilka decreased significantlycompared to raw breaded Kilka, while it was absolutely reverse for fat content. Overall fatcontent in tempura batter treatment was significantly lower than that of simple battertreatment (P≤0.05). Presence of hydrocolloids, namely proteins, starch, gum, and otherpolysaccharides, in tempura batter may prohibit moisture evaporation and placement with oilduring frying process in addition to boosting water holding capacity through confining watermolecules. During frying process, fatty acids composition of breaded Kilka with variousbatters changed so that rates of some fatty acids such as Palmitic acid (C16:0), Stearic acid(C18:0), Oleic acid (C18:1 ù-9cis), and linoleic acid (C18:3 ù-3) increased considerablyfollowing frying; however, ù-3/ù-6, PUFA/SFA, and EPA+DHA/C16:0 ratios (Polyan index)decreased significantly after frying. ù-3/ù-6, PUFA/SFA, and EPA+DHA/C16:0 ratios intempura batter treatment were higher than those of simple batter treatment which is anindicator of higher nutritional value of breaded Kilka with tempura batter. Significantelevations were found in peroxide, thiobarbituric acid, and free fatty acids in fried breaded Kilka samples compared to raw samples which points to fat oxidation during cooking process.Overall microorganism count and coliform count decreased following heating process. Bothbreaded Kilka samples were of high sanitation quality at zero-phase according to ICMSFStandard. The results acquired from organoleptic evaluation declared that odor, cohesiveness,and general acceptability indices, among others, had significant differences between thetreatments (P≤0.05). In all evaluated properties, breaded Kilka with tempura batter indifferent phases gained higher scores than breaded Kilka with simple batter. During coldstorage of various treatments of breaded Kilka, total lipid content, PUFA, MUFA, ù-3, ù-3/ù-6, PUFA/SFA, Polyen index decreased significantly. The mentioned reductions inaddition to significant elevation of spoilage indices, namely peroxide, thiobarbituric acid, andfree fatty acids, during frozen storage, indicate to oxidation and enzymatic mechanismactivity during frozen storage of breaded Kilka. Considering sensory evaluation at the end ofthe fourth month and TVB-N contents exceeded eligible rate in the fourth month, shelf life ofthe products during frozen storage was set to be three months at -18°C. The results obtainedfrom statistical tests indicate to better quality of breaded Kilka processed with tempura battercompared to simple batter in terms of organoleptic evaluation, spoilage indices, and highquality of fat in various sampling phases.
    Beschreibung: PhD
    Beschreibung: Advisors: Ali Asghar Khanipour, Mehdi Soltani Counsellors: Abbasali Motallebi, Abolghasem Kamali
    Schlagwort(e): Chemistry ; Fisheries
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  • 23
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    The effect of Rosmarinus officinalis and Zataria multiflora extracts on the stability of poly unsaturated fatty acids in frozen silver carp minced (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19118 | 17408 | 2015-12-14 19:22:20 | 19118 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: The purpose of this study, Evaluation the effect of Rosmarinus officinalis and Thymus vulgaris extracts on the stability of poly unsaturated fatty acids in frozen Silver carp minced. Treatments include:Treatment 1 - Control: frozen meat packaged in conventionalTreatment 2: Frozen Silver carp minced+Thyme 300 mg/kg in normal packagingTreatment 3: Frozen Silver carp minced+Rosemary 200 mg/kg in normal packagingTreatment 4: Frozen Silver carp minced+Rosemary compound (100 mg/kg) and Thyme(100 mg/kg) in normal packagingAfter rapid freezing of samples in the spiral freezer by individual quick freezing method, tomaintain the cold temperature (-18) °C were transferred. Sampling and measurements to determine the fatty acid profile of the zero phase beginning in the first month and then every ten days, and 15 days in the second month of the third month after the monthly test.Identifying, defining and measuring the fatty acid profile by gas chromatography was performed. In this study, levels of both saturated and unsaturated fatty acids in threeexperimental and one control were identified as follows:A: saturated fatty acids: Meristic C14: 0/Palmitic C16: 0/Hepta decaenoic C17: 0/Stearic C18: 0/Arashidic C20: 0/B:Mono unsaturated fatty acids: palmitoleic C16: 1-W7/Oleic C18: 1-W9/Gadoleic C20:1-W9C:Poly unsaturated fatty acids: Linoleic C18: 2-W6/α-Linolenic C18: 3-W3D:High unsaturated fatty acids: Arachidonic C20: 4-W6 Eicosapentaenoic acid C20: 5-EPA/W3 Docosahexaenoic C22: 6-DHA/W3Results of this study was to determine, Thyme and rosemary extracts containing silver carpminced stored in freezing conditions, Stability of different types of fatty acids, monounsaturatedfatty acids, poly-unsaturated fatty acids, omega-3 and omega-6 fatty acids are. So that none of the fatty acids measured were not significant 100% increase or decrease,While changes in the fatty acid oxidation during storage time is minimized. The resultsobtained from the fatty acid profiles and indicators of their and statistical tests show that treatment with rosemary extract More stable during storage (-18) ° C In comparison with the control and other treatments are shown; And at relatively low compared to othertreatments and control samples oleic acid and linoleic acid, palmitic more.According to studies,in Silver carp minced that containing rosemary extract, end of the storage period of six months. Were usable, so even rosemary extract the shelf-lifeexamples to increase more than six months.
    Beschreibung: PhD
    Beschreibung: Advisors: A. A. Motalebi Moghanjvqy, Seyed Ebrahim Hosseini Counsellors: Ali Asghar Khanipour, Mehdi Soltani
    Schlagwort(e): Agriculture ; Chemistry ; Fisheries
    Repository-Name: AquaDocs
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  • 24
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    Application of encapsulated nisin and sodium citrate for shelf life increasing of Rainbow trout (Onchorhynchus mykiss) fillet packaged with MAP and their effect on Staphylococcus aureus (2021)
    Islamic Azad University, Science and Research Branch, Tehran, Fisheries
    In:  http://aquaticcommons.org/id/eprint/19141 | 17408 | 2016-02-01 21:04:45 | 19141 | Islamic Azad University, Science and Research Branch, Tehran
    Details
    Publikationsdatum: 2021-07-13
    Beschreibung: Nisin is a widely used naturally occurring antimicrobial effective against many pathogenic and spoilage microorganisms. It has been proposed thatreduced efficacy of nisin in foods can be improved by technologies such as encapsulation to protect it from interferences by food matrix components. Theaim of this study was using of spray dried encapsulated nisin with zein in concentration of (0.15 and 0.25 g/kg) and sodium citrate (1.5 and 2.5%) and treatments with both of them to extent the shelf life of filleted trouts packagedby Modified Atmosphere Packaging (45% CO2, 50% N2 ,5% O2) and stored at 4±1 °C for 20 days. Furthermore, to evaluate the antimicrobial efficiency of encapsulated nisin and soudium citrate the trouts fillets was inoculated withStaphylococcus aureus as an index pathogenic bacteria. Assessment of chemical spoilage indexes such as (Proxide value, Thiobarbituric acid, total volatile basenitrogen and pH) , microbial parameters (Total Plate Count, Psychrotrophic count, Lactic acid bacteria count), Staphylococcus aureus cont in treatments which were inoculated with 5 logcfu/g of this bacteria and sensory evaluation of fillets including (smell, color, texture and total acceptability) was carried out indays of 0, 4, 8, 12, 16 and 20. The results revealed that treatment with both exposure of nisin and sodium citrate showed significantly lower chemicalspoilage indexes in comparison with controls (vaccum packed and MAP)(P〈0.05). Furthermore, (nisin 0.25 g/kg sodium citrate 2.5%) treatment whichwas exposed to the maximal level used of both materials was significantly thelowest treatment with (Proxide value, Thiobarbituric acid, total volatile basenitrogen and pH) of 9.95 (meq O2/kg) , 1.55 (mgMA/kg), 29.65 (mgN/100g) and 6.65 , respectively and according to the maximal recommended level of this indices , shelf life of fillets in this treatment was esstimated 20 days.The control(vaccum packed) treatment was significantly the highest treatment with (Proxide value, Thiobarbituric acid, total volatile base nitrogen and pH) of 15.17 (meq O2/kg), 3.03 (mgMA/kg), 38.4 (mgN/100g) and 6.95 , respectively and according to the maximal recommended level of this indices , shelf life of filletsin this treatment was estimated 11 days. Also, in microbial point of view (nisin0.25 g/kg- sodium citrate 2.5%) treatment was the lowest treatment with TotalPlate Count, Psychrotrophic count, Lactic acid bacteria count andStaphylococcus aureus count of 6.7, 6.83, 5.25 and 6.04 logcfu/g respectively,and conrol (vaccum packed) treatment was the highest treatment with 9.15, 9.41, 7.7 and 9.01 logcfu/g respectively. According to the lower results of chemicaland microbial indices and higher sensory evaluated scores assessed in this research for encapsulated nisin in comparison with free nisin , it was concludedthat encapsulation of nisin with zein capsules may improve the efficiency of nisin. The measuremented values of Mass yield, Total solids content of capsules, Encapsulation efficiency, In vitro release kinetics in 200 hour for encapsulated nisin in this study was 49.89, 62, 98.31 and 69% respectively and Encapsulated particle size was lower than 674.21 μm for 90% of particles. As a consequence, nisin , in particular encapsulated nisin, and sodium citrate alone or together with and Modified Atmosphere packaging might be considered as effective tools in preventing the quality degradation of the fillets, resulting in an extension of their shelf life.
    Beschreibung: PhD
    Beschreibung: Advisors: Seyed Ebrahim Hosseini, Aboulghassem Kamali Counsellorrs: Abbasali Motallebi, Resa Pourgholam
    Schlagwort(e): Aquaculture ; Chemistry ; Fisheries
    Repository-Name: AquaDocs
    Materialart: thesis
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  • 25
    Digitale Medien
    Digitale Medien
    Interstellar molecules (1980)
    Springer
    Journal of molecular evolution 15 (1980), S. 79-101 
    Details
    ISSN: 1432-1432
    Schlagwort(e): Molecules ; Interstellar ; Chemistry ; Isotopes ; Solar system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The study of interstellar molecules broadly includes two areas of interest. One area uses the unique ability of molecules to act as probes of the physical conditions in the cold, dense, visually opaque component of the interstellar medium. The physical properties of this and other components of the interstellar medium are summarized. The other area deals with the chemistry of interstellar molecules, recent aspects of which are emphasized in this review. Gas-phase chemistry, shock chemistry, and grain surface chemistry are discussed in the context of recent observations. No present observations suggest that surface reactions are relevant, but neither can they be ruled out. Ion-molecule reactions are clearly operative, at least for the simpler species. Chemical isotope fractionation is reviewed, andd it is concluded that the complexities of the chemistry allow no cosmological conclusions to be drawn from observations of deuterium in interstellar molecules, while the presence of13C in interstellar molecules permits an estimate of the12C/13C ratio which is consistent with the current concepts of the nucleosynthesis history of the Galaxy. Possible connections between interstellar molecules and the early molecular history of the solar system are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01732663
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  • 26
    Digitale Medien
    Digitale Medien
    Proteins of the periodontium (1977)
    Springer
    Calcified tissue international 23 (1977), S. 39-44 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Dental cementum ; Collagen ; Protein ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary Cyanogen bromide (CNBr) peptides were prepared of the insoluble collagen of bovine dental cementum. Following chromatographic separation, the peptides were identified by their amino-acid composition. Type I collagen ([α1(I)]2α2) accounted for more than 90% of the organic matrix, while Type III collagen ([α1(III)]3) was present at a level of approximately 5%. Amino-acid analyses revealed that the CNBr peptides from α1(I) and α2 chains of cementum closely resembled the corresponding peptides from calf skin. The only systematic difference was a higher level of hydroxylation of prolyl and lysyl residues of the cementum peptides.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012764
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  • 27
    Digitale Medien
    Digitale Medien
    The concentration and distribution of uranium in human skeletal tissues (1971)
    Springer
    Calcified tissue international 7 (1971), S. 150-162 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Uranium ; Bone ; Distribution ; Fission ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Une concentration moyenne de 2.4×10−8 g U/g de cendre a été obtenue à partir de l'os humain normal. La microdistribution de l'uranium dans l'os indique que cet élément est surtout limité à surface de l'endoste et, en particulier, aux surfaces de l'os lamellaire et aux parois des canaux de Havers, ouverts dans l'os corticol. Cette répartition suggère que l'uranium se présente sous une forme chimique impropre à son incorporation dans l'apatite osseux: il ne semble donc pas exister une distribution diffuse significative de l'uranium dans l'os.
    Kurzfassung: Zusammenfassung Eine mittlere Konzentration von 2,4×10−8 g Uran/g Asche wurde in normalen menschlichen Knochen gefunden. Die Feinverteilung von Uran im Knochen zeigt, daß dieses Element hauptsächlich an der endostalen Oberfläche vorkommt, insbesondere an der Oberfläche des trabeculären Knochens und an den Wänden der offenen Haversschen Kanäle im kortikalen Knochen. Diese Verteilung läßt vermuten, daß Uran in einer chemischen Form vorliegt, welche sich für den Einbau in das Knochenapatit nicht eignet. Daraus folgt, daß keine signifikante diffuse Verteilung des Urans innerhalb des Knochens vorliegt.
    Notizen: Abstract A mean concentration of 2.4×10−8 g U/g ash has been obtained for normal human bone The microdistribution of uranium in bone indicates that this element is mainly restricted to endosteal surfaces; in particular the surfaces of trabecular bone and the walls of open Haversian canals in cortical bone. This distribution suggests that uranium is present in a chemical form that is not acceptable for incorporation into bone apatite and consequently there does not appear to be a significant diffuse distribution of uranium throughout bone.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02062603
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  • 28
    Digitale Medien
    Digitale Medien
    Histological, autoradiographic and microchemical studies of spontaneously healing osteochondral articular defects in adult rabbits (1971)
    Springer
    Calcified tissue international 8 (1971), S. 54-72 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Morphology ; Glycosaminoglycans ; Cartilage ; Chemistry ; Audioradiography ; Healing
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Une perte de substance ostéo-cartilagineuse, de taille limitée et identique, est réalisée chez le lapin adulte et la cicatrisation est étudiée histologiquement et par autoradiographie après marquagein vitro au35S-sulfate. Une analyse microchimique est pratiquée pour le contenu et la composition en glycosaminoglycanes. 1. Entre la première semaine et la 4ème et 8ème semaine, un tissu conjonctif non-métachromatique se différencie en un cartilage métachromatique et la quantité de sulfate de chondroitine augmente de façon significative aux dépens des glycoprotéines. 2. Jusqu'à la 4ème semaine, la perte de substance est surtout comblée par de l'os néoformé: après cette période, la région est comblée au delà de la limite de la surface articulaire. 3. Le cartilage hyalin, ressemblant morphologiquement, autoradiographiquement et chimiquement au cartilage articulaire, en ce qui concerne la distribution en glycosaminoglycanes, constitute la surface articulaire de la perte de substance comblée dans un tiers des cas après 8 semaines. Le cartilage hyalin s'observe surtout dans les régions où de l'os néoformé a comblé la cavité médullaire. 4. Dans les deux tiers des cas, après 8 semaines, les surfaces articulaires des zones comblées comportent, non seulement du cartilage, mais aussi du tissu fibreux se formant essentiellement sur les parties latérales et dans les régions, où la cavité médullaire, fliant face, à la surface articulaire, n'a pas été comblée par du tissue osseux. La fraction glycoprotéique augmente par rapport à la fraction chondroitine sulfate. 5. Dans la majorité des cas, après 20 semaines, le cartilage néoformé subit des phénomènes dégénératifs, qui se traduisent par une diminution en chondroitine sulfate.
    Kurzfassung: Zusammenfassung Bei ausgewachsenen Kaninchen wurde ein begrenzter, standardisierter, osteochondraler Defekt hervorgerufen, und das regenerierte Gewebe wurde histologisch und autoradiographisch durch Markierung in vitro mit35S-Sulfat und durch mikrochemische Bestimmung des Gehaltes und der Zusammensetzung der Glykosaminglykane untersucht. Die wichtigsten Befunde waren: 1. Zwischen 1 und 4–8 Wochen veränderte sich nichtmetachromatisches Bindegewebe zu metachromatisch gefärbtem Knorpel, und der Anteil an Chondroitin-Sulfat nahm auf Kosten der Glykoproteine signifikant zu. 2. Bis zu 4 Wochen war der Hauptteil des defekten Gebietes mit neugebildetem Knochen gefüllt; nach dieser Zeit lag dieser Bezirk oberhalb der Verknöcherungsgrenze in Richtung der Gelenkoberfläche. 3. Nach 8 Wochen bestand die Gelenkoberfläche des defekten Gebietes in einem Drittel der Fälle aus hyalinem Knorpel, der morphologisch, autoradiographisch und chemisch dem Gelenkknorpel in Bezug auf die Verteilung von Glykosaminoglykanen glich. Hyaliner Knorpel wurde hauptsächlich an Stellen beobachtet, wo neugebildeter Knochen die Markhöhle geschlossen hatte. 3. Nach 8 Wochen bestand die Gelenkoberfläche des defekten Gebietes in einem Drittel der Fälle aus hyalinem Knorpel, der morphologisch, autoradiographisch und chemisch dem Gelenkknorpel in Bezug auf die Verteilung von Glykosaminoglykanen glich. Hyaliner Knorpel wurde hauptsächlich an Stellen beobachtet, wo neugebildeter Knochen die Markhöhle geschlossen hatte. 4. Nach 8 Wochen bestanden Teile der Gelenkoberfläche des Defektes in zwei Dritteln der Fälle nicht nur aus Knorpel, sondern auch aus fibrösem Gewebe, welches vor allem in den seitlichen Teilen des Defektes und an Stellen vorlag, wo die Markhöhle gegenüber der Gelenkoberfläche nicht mit Knochengewebe verschlossen worden war. Die Glykoproteinfraktion nahm im Vergleich zur Chondroitin-Sulfatfraktion zu. 5. Nach 20 Wochen zeigten sich in den meisten Fällen bei neugebildetem Knorpel degenerative Veränderungen, welche durch eine gewisse Abnahme des Chondroitin-Sulfats wiedergegeben wurden.
    Notizen: Abstract A limited, standardized osteochondral defect was created in adult rabbits and the regenerated tissue was examined histologically and autoradiographically after labellingin vitro with35S-sulphate, and microchemically for its content and composition of glycosaminoglycans. The principal findings were: 1. Between 1 week and 4 to 8 weeks, non-metachromatic connective tissue differentiated to metachromatically stained cartilage, and the proportion of the chondroitin sulphate increased significantly at the expense of the glycoproteins. 2. Up to 4 weeks, the major part of the defect area was filled with newly formed bone; after this time, the area lay above the level of the “tidemark”, towards the articular surface. 3. Hyaline cartilage with morphological, autoradiographic and chemical resemblance to the articular cartilage in terms of the distribution of glycosaminoglycans constituted the articular surface of the defect area in one-third of the cases at observation times after 8 weeks. Hyaline cartilage was observed mainly in areas where newly formed bone had closed the medullary cavity. 4. In two-thirds of the cases, after 8 weeks, parts of the articular surface of the defect consisted not only of cartilage but also of fibrous tissue, occurring mainly in the lateral parts of the defect and in areas where the medullary cavity facing the articular surface had not been sealed by bone tissue. The glycoprotein fraction increased relative to the chondroitin sulphate fraction. 5. In most cases after 20 weeks, newly-formed cartilage underwent degenerative changes, which were reflected in some reduction of the chondroitin sulphate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010122
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  • 29
    Digitale Medien
    Digitale Medien
    Precipitation of calcium phosphates from electrolyte solutions (1972)
    Springer
    Calcified tissue international 10 (1972), S. 82-90 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Calcium ; Phosphate ; Precipitation ; Kinetics ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé La cinétique de la formation et de la transformation des précipités de phosphate de calcium, obtenus en mélangeant de volumes égaux de solutions à 6×10−3 M de calcium total et/ou phosphate total est étudiée à 25°C. Les solutions de phosphate sont préajustées à un pH de 7.4. Les changements de pH et de turbidité des solutions sont suivis simultanément en fonction du temps. Les précipités sont isolés à des intervalles de temps variables et caractérisés par diverses méthodes physico-chimiques. Initialement un précipité avec un rapport molaire Ca/P de 1.5, amorphe aux rayons X et en diffraction électronique, est formé. Le spectre IR indique la présence de PO 4 3− et de HPO 4 2− . Après une période métastable, on observe la précipitation d'un matériel cristallin dans ou sur la phase amorphe. Vingt quatre heures après préparation de l'échantillon les précipités présentent surtout les caractères du phosphate octocalcique.
    Kurzfassung: Zusammenfassung Die Kinetik der Bildung und Transformation von Calciumphosphat-Niederschlägen wurde bei 25°C untersucht. Es wurden dazu gleiche Volumen von Lösungen gemischt, bei einer Konzentration von 6×10−3M totales Calcium und/oder totales Phosphat. Die Phosphatlösungen wurden zuerst auf pH 7,4 eingestellt. Veränderungen des pH und Trübung der Lösungen wurden gleichzeitig als eine Funktion der Zeit aufgezeichnet. Niederschläge wurden in verschiedenen Zeitintervallen isoliert und mit verschiedenen physiko-chemischen Methoden charakterisiert. Am Anfang wurde ein Niederschlag mit einem molaren Ca/P-Verhältnis von 1,5, im Röntgenbild und in der Elektronendiffraktion amorph, gebildet. Infrarotspektren deuteten die Anwesenheit von PO 4 3− - und HPO 4 2− -Ionen an. Nach einer metastabilen Periode erfolgte ein Niederschlag aus kristallinem Material innerhalb oder auf der amorphen Substanz. 24 Std nach der Herstellung der Proben zeigten die Niederschläge in der Hauptsache die Charakteristiken von Octocalciumphosphat.
    Notizen: Abstract The kinetics of the formation and transformation of calcium phosphate precipitates obtained by mixing equal volumes of solutions, 6×10−3 M in total calcium and/or total phosphate was investigated at 25°. The phosphate solutions were preadjusted to pH 7.4. Changes of the pH and turbidity of the solutions were followed simultaneously as a function of time. Precipitates were isolated at various time intervals and characterized by different physicochemical methods. Initially a precipitate with a molar Ca/P ratio of 1.5, amorphous to X-ray and electron diffraction was formed. IR spectra indicated the presence of PO 4 3− and HPO 4 2− ions. After a period of metastability, precipitation of a crystalline material within or upon the amorphous matter occurred. Twenty four hours after sample preparation the precipitates showed mainly the characteristics of octacalcium phosphate.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012538
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  • 30
    Digitale Medien
    Digitale Medien
    Studies in the basic mineralizing system, CaO-P2O5-H2O (1974)
    Springer
    Calcified tissue international 14 (1974), S. 3-14 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Hydroxyapatite ; Mineral ; Phase ; Chemistry ; Synthesis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Des diagrammes de phase d'équilibre ont été déterminés pour le système CaO-P2O5-H2O en utilisant des techniques de synthèse hydrothermique au cours de variatio nsde température allant de 300–600° et 2 Kb H2O de pression. De l'hydroxyapatite bien cristallisé a été synthétisé et caractérisé. De faibles variations de paramètres de la maille cristalline, liées à la température de synthèse et composition globale du matériel initial, ont été déterminées. Des conditions chimiques précises sont nécessaires pour obtenir de l'apatite, en tant que seule phase solide en équilibre dans la solution. Les résultats de diagramme de phase d'équilibre sont comparés avec ceux obtenus dans des milieux synthétiques.
    Kurzfassung: Zusammenfassung Es wurden Gleichgewichts-Phasendiagramme für das System CaO-P2O5-H2O bestimmt, indem hydrothermale Synthese-Techniken im Temperaturbereich von 300–600° und bei einem Druck von 2 Kb H2O verwendet wurden. Es wurde gut-kristallisiertes Hydroxyapatit erzeugt und charakterisiert. Es wurden geringe Unterschiede in den Parametern der Zelleinheiten festgestellt, welche von der angewandten Temperatur und der Zusammensetzung des Startmaterials abhingen. Es waren genaue chemische Bedingungen nötig, um Apatit als die einzige feste Phase im Gleichgewicht mit der Lösung zu erhalten. Die Resultate der Gleichgewichts-Phasendiagramme werden mit früheren Untersuchungen mit der Synthesetechnik verglichen.
    Notizen: Abstract Equilibrium phase diagrams have been determined for the system CaO-P2O5-H2 using hydrothermal synthesis techniques in the temperature range 300–600° and 2 Kb H2O pressure. Well-crystallized hydroxyapatite has been produced and characterized. Small variations in unit cell parameters dependent on temperature of synthesis and bulk composition of the starting materials have been determined. Precise chemical conditions were required to obtain apatite as the only solid phase in equilibrium with solution. Equilibrium phase diagram results are compared with previous synthetic investigations.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02060279
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  • 31
    Digitale Medien
    Digitale Medien
    Studies on fluorapatite (1973)
    Springer
    Calcified tissue international 13 (1973), S. 259-270 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Fluorapatite ; Exchange ; Chemistry ; Crystallography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Un échantillon minéral provenant de Burgess, Canada s'est révélé être un speciment exceptionnellement pur de fluoroapatite après analyse chimique et cristallographique. La composition globale de cet échantillon est la suivante: $$(Ca^2 )9.98(Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )0.02(PO_4^{3 - } )5.98(HCO_3^ - ,CO_3^{2 - } )0.02(F^ - )2$$ . L'axe cristallographique C est de 6.865 A et l'axe a de 9.374 A. Des expériences d'échanges réalisés à l'aide de45Ca,32P et18F indiquent la présence de gros cristallites de surface spécifique de l'ordre de 1 m2/g. Il apparait que l'interprétation physique des processus d'échange ne nécessite pas l'existence de compartiments séparés, avec chacun son propre facteur cinétique, les échanges semblent être simplement liés à un changement exponentiel dans l'énergie libre de la réaction. Pour la réaction suivante: $$(Ca)_5 (PO_4 )_3 OH solide + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F solide + (OH^ - )$$ , la constante thermodynamique de 101.26 a été calculée, suggérant que le fluorapatite se forme toujours aux dépens de l'hydroxyapatite dans des conditions physiologiques. Cette transformation se continue en abaissant le pH.
    Kurzfassung: Zusammenfassung Eine Mineralprobe aus Burgess, Kanada, erwies sich nach chemischer und kristallographischer Analyse als außergewöhnlich reines Fluorapatit. Die Gesamtzusammensetzung entspricht: $$(Ca^{2 + } )_{9,98} (Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )_{0,02} (PO_4^{3 - } )_{5,98} (HCO_3^ - ,CO_3^{2 - } )_{0,02} (F^ - )_2 $$ . Die kristallographische c-Achse wurde bestimmt und ergab 6,865 Å, und die a-Achse ergab 9,374 Å. Austauschwerte, welche durch Anwendung von45Ca,32P und18F erhalten wurden, deuteten auf große Kristalliten mit einer spezifischen Oberfläche von ca. 1 m2/g. Die Befunde deuten darauf hin, daß für die physikalische Erklärung des Austauschvorganges keine separaten Kompartimente mit eigenen kinetischen Faktoren nötig sind, sondern daß der Austausch mit dem exponentiellen Wechsel in der freien Energie der Reaktion in einfacher Beziehung steht. Für die Reaktion $$(Ca)_5 (PO_4 )_3 OH_{in fester Form} + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F_{in fester Form} + (OH^ - )$$ wurde als thermodynamische Konstante 101,26 errechnet, was darauf deutet, daß unter physiologischen Bedingungen immer Fluorapatit auf Kosten von Hydroxyapatit entsteht. Diese Umwandlung wird erhöht, wenn das pH erniedrigt wird.
    Notizen: Abstract A mineral specimen from Burgess, Canada, proved upon chemical and crystallographic analyses to be an exceptionally pure sample of fluorapatite. The over-all composition corresponds to $$(Ca^{2 + } )_{9.98} (Sr^{2 + } ,Na^ + ,K^ + ,Mg^{2 + } )_{0.02} (PO_4^{3 - } )_{5.98} (HCO_3^ - ,CO_3^{2 - } )_{0.02} (F^ - )_2 $$ . The crystallographic c-axis was determined to be 6.865 Å, and the a-axis 9.374 A. Exchange data obtained by employing45Ca,32P, and18F indicate the presence of large crystallites with a specific surface of the order of 1 m2/g. It is indicated that the physical interpretation of the exchange process does not require the existence of separate departments, each with its own kinetic factor, but that the exchange may be simply related to the exponential change in the free energy of the reaction. For the reaction $$(Ca)_5 (PO_4 )_3 OH_{solid} + (F^ - ) \rightleftarrows (Ca)_5 (PO_4 )_3 F_{solid} + (OH^ - )$$ the thermodynamic constant has been calculated to be 101.26, implying that fluorapatite always will form at the expense of hydroxyapatite under physiologic conditions. This transformation will be furthered by lowering the pH.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02015416
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  • 32
    Digitale Medien
    Digitale Medien
    Calcium deficiency, pregnancy, and lactation in rats (1977)
    Springer
    Calcified tissue international 23 (1977), S. 87-94 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Calcium ; Osteoporosis ; Lactation ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The calcium homeostatic mechanism was challenged in adult female rats by feeding them a calcium-deficient diet containing oxalate, and by subjecting them to pregnancy and lactation. The regimen caused a substantial weight loss, especially in those animals which reared their young well. Severe hypocalcaemia was observed in the lactating rats. Serum-P was slightly elevated. The content of hydroxyproline in serum was considerably elevated, reflecting the degree of calcium deprivation. Serum proteins were least influenced. The calcium depriving regimen reduced the growth of long bones, but did not stop it. The ash content of the bones was considerably reduced, the degree of reduction depended on the degree of calcium deprivation. Ash as percentage of total bone organ was reduced, but not to the same extent as total ash. Analyses of different parts of femur showed that the proximal and distal parts had lost more bone mineral than the diaphyseal shaft. The ash content of cortical bone tissue from the femur was estimated by a volumetric method. No differences were observed between test groups and controls, indicating that no measurable amounts of bone mineral had been removed from the walls of the vascular canals or by osteocytic osteolysis. Planimetric determinations on cross sections from femora disclosed that a great amount of bone had been removed from the endosteal surface of the diaphysis, while the periosteal surface demonstrated reduced bone apposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012771
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  • 33
    Digitale Medien
    Digitale Medien
    Mineralization during the molt cycle inLirceus brachyurus (Isopoda: Crustacea) (1973)
    Springer
    Calcified tissue international 12 (1973), S. 125-136 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Mineralization ; Molt ; Isopod ; Chemistry ; Light microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Au cours de la phase inhabituelle de mue d'un isopode d'eau courante,Lirceuts brachyrus, la moitié postérieure de l'exosquelette est éliminée 24 heures avant la moitié antérieure. A ce stade, une reminéralisation se développe dans la partie postérieure alors que la partie antérieure est dans un stade de pré-mue. Le pourcentage de différence en calcium dans les deux moitiés à mi-mue et mue complète est respectivement de 22% (p〈0.01) et 33% (p〈0.01), indiquant une complexation du calcium pendant la mue. La rapidité de la reminéralisation est illustrée par le fait que le contenu minéral total double dans la partie postérieure entre la mi-mue et la mue totale et dans la partie antérieure entre la fin de la mue et un jour après. Le carbonate de calcium, sous forme de calcite, a pu être identifié par diffraction électronique de coupes fines des téguments.
    Kurzfassung: Zusammenfassung Während der ungewöhnlichen Häutungssequenz des Frischwasser-IsopodenLirceus brachyurus (Harger) wird die hintere Hälfte des äußeren Skeletts 24 Std vor der vorderen Hälfte abgestoßen. In der halbgehäuteten Phase erfolgt Remineralisation im hinteren Teil, während der vordere Teil in einem Vorhäutungszustand ist. Der prozentuale Unterschied des Calciums in den zwei Hälften bei Halb- und Vollhäutungszustand ist 22% (p〈0,01) bzw. 33% (p〈0,01), was andeutet, daß Calcium während der Häutung abgesondert wird. Die Geschwindigkeit der Remineralisation erhellt aus der Tatsache, daß sich der Gesamtmineralgehalt im hinteren Teil zwischen Halt- und Vollhäutung, in der vorderen Hälfte jedoch zwischen Endhäutung und einem Tag nach der Häutung verdoppelt. Calciumcarbonat in kristalliner Calcitform wurde mittels Elektronendiffraktion von dünnen Hautschnitten nachgewiesen.
    Notizen: Abstract During the unusual molt sequence of the fresh-water isopod,Lirceus brachyrus (Harger), the posterior half of the exoskeleton is shed 24 hours before the anterior half. At the half-molt stage, occurs in the posterior part while the anterior portion is in a pre-molt condition. The percentage difference in calcium in the two halves at half-molt and full-molt is22 (p〈0.01) and33 (p〈0.01) respectively, an indication that calcium is sequestered during The rapidity of remineralization is illustrated by the fact that the total mineral content doubles in the posterior part between half and full molt and in the anterior half between the end of molt and one day after ecdysis. Calcium carbonate in the calcite cystalline form was demonstrated by electron diffraction of thin sections of the integument.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02013728
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  • 34
    Digitale Medien
    Digitale Medien
    The effects of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on bone and serum chemistry in rabbits (1974)
    Springer
    Calcified tissue international 16 (1974), S. 145-152 
    Details
    ISSN: 1432-0827
    Schlagwort(e): EHDP ; Bone ; Chemistry ; Serum ; Rabbits
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Abstract The effects of disodium ethane-1-hydroxy-1,1-diphosphonate (EHDP) on bone and serum chemistry were investigated in adult rabbits. EHDP was administered by subcutaneous injection at doses of 0.25, 2.5 and 10 mg/kg body weight/day for of 28 days. Blood samples were obtained weekly from each rabbit and serum levels of total calcium, ionized calcium, inorganic phosphate and alkaline phosphatase were determined. At the end of the treatment period all rabbits were sacrificed and the tibiae removed for chemical analysis and histological evaluation. The effect of EHDP administration on serum chemistry was both dose- and time-related. The highest of the three doses, 10 mg/kg/day, resulted in a time-related decrease in total serum calcium. This dose also caused a rapid but transient reduction in serum ionized calcium. The effect of EHDP on serum inorganic phosphate was biphasic. Administration of 2.5 mg/kg/day resulted in a time-related elevation in this parameter, whereas the 10 mg/kg/day dose resulted in a time-related hypophosphatemic response. There were no significant drug-related changes in tibial fat-free dry weight, ash weight, total calcium or total phosphorus values. However, administration of 2.5 and 10 mg/kg/day EHDP resulted in increased osteoid tissue as measured histologically. These results are compared with data from other EHDP studies, and discussed in relation to the maturity and growth-state of the experimental animals.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02008220
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  • 35
    Digitale Medien
    Digitale Medien
    Isolation and properties of fluorescent components associated with calcified tissue collagen (1971)
    Springer
    Calcified tissue international 8 (1971), S. 197-210 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Fluorescence ; Calcium ; Collagen ; Chemistry ; Bone ; Dentine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Des composants fluorescents de l'os et la dentine sont séparés des hydrolysats alcalins de leur marice sur des colonnes Sephadex C25 CM d'échange cationique. Les concentrations en fluorescence et le spectre d'excitation (λ max 330 nm) et d'émission (λ max 395 nm) sont les mêmes que ceux observés au niveau des matrices intactes et gélatinisées. Les paramètres de fluorescence ne sont pas altérés par hydrolyse. La filtration sur gel à l'aide de colonnes Sephadex G 10 perment de différencier le matériel isolé en deux composants, ayant la même fluorescence et la même absorption UV. La fluorescence est indépendante de pH de 3.5–9.5. Des études de dialyse et de filtration sur gel de matrices gélatinisées indiquent une association étroite du matériel fluorescent avec les chaines polypeptidiques de collagène.
    Kurzfassung: Zusammenfassung Fluorescierende Bestandteile aus Knochen und Dentin wurden in Sephadex C25 CM Kationen-Austauschersäulen von alkalischen Hydrolysaten ihrer Matrices getrennt. Die Fluorescenzintensitäten sowie die Erregungs- (λ max 330 nm) und Emissions- (λ max 395 nm) Spektren waren dieselben wie bei intakten und gelatinisierten Matrices. Die Fluorescenzparameter wurden durch die Hydrolyse nicht verändert. Eine Gelfiltration über Sephadex-G10-Säulen trennte das isolierte Material in 2 Komponenten auf, welche gleiche Fluorescenz- und UV-Absorptionseigenschaften zeigten. Im pH-Bereich zwischen 3,5 und 9,5 war die Fluorescenz unabhängig vom pH. Dialysierversuche sowie Gelfiltrationsexperimente mitden gelatinisierten Matrices zeigten eine starkgefügte Bindung des fluorescierenden Materials mit den Polypeptidketten des Kollagens.
    Notizen: Abstract Fluorescent components in bone and dentine were separated from alkaline hydrolysates of their matrices on Sephadex C25 CM cationic exchange columns. The fluorescence levels, and the excitation (λ max 330 nm) and emission (λ max 395 nm) spectra, were the same as those observed in the intact and gelatinised matrices. The fluorescence parameters were unaltered by the hydrolysis procedure. Gel filtration on Sephadex G. 10 columns further resolved the isolated material into two components with the same fluorescence and UV absorption properties. The fluorescence was independent of pH over the range 3.5–9.5. Dialysis and gel filtration studies on the gelatinised matrices indicated a firmly-bonded association of the fluorescent material with the collagen polypeptide chains.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010138
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  • 36
    Digitale Medien
    Digitale Medien
    The importance of energetic particle precipitation on the chemical composition of the middle atmosphere (1980)
    Springer
    Pure and applied geophysics 118 (1980), S. 128-151 
    Details
    ISSN: 1420-9136
    Schlagwort(e): Galactic cosmic rays ; Solar proton events ; Particle precipitation ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract An assessment is made of the relative contribution of certain classes of energetic particle precipitation to the chemical composition of the middle atmosphere with emphasis placed on the production of odd nitrogen and odd hydrogen species and their subsequent role in the catalytic removal of ozone. Galactic cosmic radiation is an important source of odd nitrogen in the lower stratosphere but since the peak energy deposition occurs below the region where catalytic removal of O3 is most effective, it is questionable whether this mechanism is important in the overall terrestrial ozone budget. The precipitation of energetic solar protons can periodically produce dramatic enhancement in upper stratospheric NO. The long residence time of NO in this region of the atmosphere, where catalytic interaction with O3 is also most effective, mandates that this mechanism be included in future modelling of the global distribution of O3. Throughout the mesosphere the precipitation of energetic electrons from the outer radiation belt (60°≲Λ≲70°) can sporadically act as a major local source of odd hydrogen and odd nitrogen leading to observable O3 depletion. Future satellite studies should be directed at simultaneously measuring the precipitation flux and the concomitant atmosphere modification, and these results should be employed to develop more sophisticated models of this important coupling.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01586448
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  • 37
    Digitale Medien
    Digitale Medien
    Comparative chemistry of amorphous and apatitic calcium phosphate preparations (1972)
    Springer
    Calcified tissue international 10 (1972), S. 171-197 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Amorphous ; Crystalline ; Calcium phosphate ; Chemistry ; Composition
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Des échantillons non lavés de phosphate de calcium amorphe (ACP) contiennent une fraction labile, non remplaçable, riche en phosphate acide avec un rapport Ca/P faible: cette fraction est perdue de façon irréversible au cours du lavage. De l'ACP frais, précipité entre pH 6.6–10.6, varie dans un rapport molaire Ca/P de 1.18 à 1.50 et dans un rapport HPO 4 2− /P total de 33.0% à 10.1%. A pH 7.40, de l'ACP frais a un rapport molaire Ca/P de 1.36±0.02 et contient 22.8 (±2.2)% HPO 4 2− . Les résultats obtenus avec du précipité non lavé ne peuvent s'expliquer par du Ca2+ emprisonné et de l'HPO 4 2− ou du Na+, Cl− et CO 3 2− exogènes. Les phosphates de calcium amorphes constituent une classe de sels ayant des caractères chimiques variables et des propriétés physiques identiques, comparables au verre. Le CaHPO4·xH2O non cristallin peut être un ACP, surtout au cours des phases précoces de formation. A des pH physiologiques, l'ACP se transforme en petits cristaux applatis contenant de fortes quantités de phosphate acide facilement remplaçable. Le fait de laver la couche de surface produit un changement chimique dans les nouveaux cristaux: des cristaux non lavés donnent des diagrammes de diffraction d'apatite peu cristallins, ainsi que des spectres infra-rouges peu nets, intermédiaires entre des apatites et du phosphate octocalcique. Des explications structurales sont proposées et les compositions minérales amorphe/cristalline de l'os et du cartilage sont recalculées.
    Kurzfassung: Zusammenfassung Ungewaschene Proben von amorphem Calciumphosphat (ACP) enthalten eine unersetzliche labile Fraktion, welche reich an saurem Phosphat ist und ein niederes Ca/P-Verhältnis hat und welche während des Waschprozesses unwiderruflich verloren geht. Natives ACP, welches im pH-Bereich 6,6–10,6 ausgefällt wurde, variierte im molaren Ca/P-Verhältnis zwischen 1,18 und 1,50 und in HPO 4 2− /totales P zwischen 33,0 und 10,1%. Bei pH 7,40 hatte natives ACP ein molares Ca/P-Verhältnis von 1,36±0,02 und enthielt 22,8 (±2,2)% HPO 4 2− . Die Werte beim ungewaschenen Niederschlag rühren weder von aus dem Überstand aufgenommenem Ca2+ und HPO2−, noch von außen kommendem Na+, Cl− und CO 3 2− her. Die amorphen Calciumphosphate werden als eine Klasse von Salzen erkannt, welche veränderliche chemische, aber identische glasartige physicochemische Eigenschaften haben. Nicht kristallines CaHPO4·xH2O kann auch ein ACP sein, besonders in den frühen Bildungsstadien. Bei physiologischem pH verwandelt sich ACP in kleine plattenförmige Kristalle, welche große Mengen von leicht ersetzbarem saurem Phosphat enthalten. Das Waschen dieser Oberflächenschicht erzeugte chemische Veränderungen in den resultierenden Kristallen; ungewaschene Kristalle zeigten ein Diffraktionsmuster, das nur schwach demjenigen des kristallinen Aspatites glich, aber ein schlecht aufgelöstes Infrarotspektrum, welches zwischen Apatit und Octocalciumphosphat war. Es werden strukturelle Erklärungen für alle diese Phenomena diskutiert, und revidierte amorph/kristalline Mineralzusammensetzungen von Knochen und Knorpel wurden neu berechnet.
    Notizen: Abstract Unwashed samples of amorphous calcium phosphate (ACP) contain an irreplaceable labile fraction, rich in acid phosphate and low in Ca/P ratio, which is irreversibly lost during the washing process. Native ACP precipitated in the pH range 6.6–10.6 varied in Ca/P molar ratio from 1.18 to 1.50 and in HPO 4 2− /total P from 33.0% to 10.1%. At pH 7.40, native ACP had a Ca/P molar ratio of 1.36±0.02 and contained 22.8 (±2.2)% HPO 4 2− . Unwashed precipitate data could not be attributed to either trapped supernatant Ca2+ and HPO 4 2− or extraneous Na+, Cl−, and CO 3 2− . The amorphous calcium phosphates are recognized as a class of salts having variable chemical but identical glass-like, physicochemical properties. Non-crystalline CaHPO4·xH2O may also be an ACP, especially during early formative stages. At physiological pH, ACP transforms to small platy crystals containing large amounts of readily-replaceable acid phosphate. Washing this surface layer produced chemical alterations in the resultant crystals; unwashed crystals had poorly-crystalline apatitic diffraction patterns but exhibited poorly-resolved infrared spectra intermediate between apatite and octacalcium phosphate. Structural explanations for all these phenomena are discussed, and revised bone and cartilage amorphous/crystalline mineral compositions have been re-calculated.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012548
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  • 38
    Digitale Medien
    Digitale Medien
    A sulphated glycopeptide in human supragingival calculus extracts (1977)
    Springer
    Calcified tissue international 23 (1977), S. 13-17 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Dental calculus ; Glycopeptide ; Chemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary A method is described for the isolation and purification of a sulphated glycopeptide from human supragingival calculus. The compound was isolated after using EDTA treatment, 2 M CaCl2 extraction, proteolytic digestion, ethanol precipitation, and finally purified by DEAE cellulose chromatography. It migrated as a single component on cellulose acetate electrophoresis, and chemical and infrared spectral analysis showed the presence of covalently attached sulphate groups. The sulphated glycopeptide was distinguished from being a sulphated glycosaminoglycan.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02012761
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  • 39
    Digitale Medien
    Digitale Medien
    Partial purification and characterization of the bone resorption factor fromActinomyces viscosus (1982)
    Springer
    Calcified tissue international 34 (1982), S. 49-53 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Bacterial amphophile ; Purification ; Chemistry ; Resorption ; Ca influx ; Cyclic AMP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The bone resorptive factor and amphipathic antigen (AcA) previously identified by us in preparations fromActinomyces viscosus have been partially purified, characterized chemically, and compared. They elute at the same location on chromatography with Ac 22. The fatty acid composition of AcA and the bone resorptive factor is the same. Some differences in carbohydrate composition are observed. TheActinomyces factor does not affect calcium influx or cyclic AMP in isolated bone cells. Therefore it is concluded that AcA stimulates resorption either by gaining entrance into bone cells or by way of a yet undetermined second messenger.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02411208
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  • 40
    Digitale Medien
    Digitale Medien
    The mineralization of hair follicle tissue (1971)
    Springer
    Calcified tissue international 8 (1971), S. 228-236 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Skin ; Calcinosis ; Keratin ; Chemistry ; X-ray diffraction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Des études histologiques antérieures ont montré que le follicle pileux est particulièrement susceptible de se calcifier, lorsque la peau de rats hypercalcémiques est lésée. Des analyses chimiques et par diffraction aux rayons X du follicule ont confirmé ce résultat. — En se basant sur l'augmentation du calcium et du phosphore, les calcifications débutent dans le tissue folliculaire 6–12 h après une blessure d'intensité moyenne de la peau de rats, ayant reçu du dihydrotachysterol (DHT), et 24–48 h après une blessure similaire chez des rats non injectés. Les diagrammes de diffraction aux rayons X sont diffus. Trois heures après la blessure, on note une augmentation du calcium du tissu folliculaire qui ne semble pas en rapport avec le DHT qui traduit probablement une liaison de calcium plutôt qu'un dépot minéral.
    Kurzfassung: Zusammenfassung Frühere histologische Untersuchungen haben gezeigt, daß der Haarfollikel besonders anfällig für Verkalkungen ist, wenn die Haut von hypercalcämischen Ratten verletzt wird. Dieses Resultat wurde nun durch direkte chemische Bestimmungen und Röntgendiffraktions-analysen von Follikelgewebe bestätigt. Aufgrund der erhöhten Calcium- und Phosphatwerte kann gesagt werden, daß nach einer leichten Quetschung der Haut von Ratten, die mit Dihydrotachysterol (DHT) behandelt wurden, im Haarfollikelgewebe nach 6–12 Std Mineral-ablagerungen stattfanden, wogegen Kontrollratten mit der gleichen leichten Hautverletzung diese Ablagerungen erst nach 24–48 Std zeigten. Röntgendiffraktionsanalysen ergaben ein diffuses Apatit-Muster. Innerhalb 3 Std nach der Verletzung wurde ein Anstieg des Calcium-gehaltes im Follikelgewebe beobachtet, der nicht im Zusammenhang mit der DHT-Behandlung stand, also nicht eine Mineralablagerung, sondern eher eine Bindung von Calcium widerspiegelte.
    Notizen: Abstract Previous histological investigations have shown that the hair follicle is particularly susceptible to mineralization when the skin of hypercalcaemic rats is injured. Direct chemical and X-ray diffraction analyses of follicle tissue have now confirmed this finding. As judged by increases in both calcium and phosphorus, mineral deposits began to form in hair follicle tissue 6–12 h after a mild crush injury to the skin of rats dosed with dihydrotachysterol (DHT), and 24–48 h after a similar injury to the skin of non-dosed rats. X-ray diffraction gave a diffuse apatite pattern. Within 3 h of injury there was a rise in the calcium content of follicle tissue which was not related to DHT-dosing and which was probably a reflection of calcium binding rather than mineral deposition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010141
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  • 41
    Digitale Medien
    Digitale Medien
    A computer program for calculating the activities of calcium and orthophosphate ions in biological fluids and related synthetic solutions (1971)
    Springer
    Calcified tissue international 8 (1971), S. 304-319 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Chemistry ; Calcium ; Phosphate ; Solubility ; Computer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Beschreibung / Inhaltsverzeichnis: Résumé Un programme d'ordinateur a été mis au point pour calculer les activités ioniques du calcium et l'orthophosphate dans un grand nombre de solutions. Dans le cas de solutions synthétiques, les calculs sont vérifiés en comparant les valeurs de pH, obtenues par ordinateur, avec celles observées expérimentalement. Des essais de ce type, avec des solutions possèdant des concentrations de calcium et d'orthophosphate trouvées dans les liquides biologiques et à des valeurs de pH variant de 3.00 à 10.00, indiquent que le programme est adapté pour des applications biologiques. Le programme n'est pas effectif pour des solutions, dans les lesquelles l'ion bromure est la source principale de la force ionique, sans doute, par manque d'équation étendue de Debye-Hückel dans ces circonstances. Aucune formation de complexe de phosphate de sodium n'a été notée à des concentrations biologiques normales.
    Kurzfassung: Zusammenfassung Es wurde ein Computer-Programm ausgearbeitet, um die Ionenaktivitäten von Calcium und Orthophosphat in einer breiten Varietät von Lösungen zu berechnen. Die Berechnungen wurden bei synthetischen Lösungen durch Vergleiche zwischen den auf diese Weise errechneten pH-Werten und den experimentell gefundenen kontrolliert. Diese Art Kontrollen mit Calcium-und Orthophosphatkonzentrationen, wie sie in biologischen Flüssigkeiten gefunden werden, und mit pH-Werten zwischen 3,0 und 10,0 wies darauf hin, daß das Programm für biologische Anwendungen geeignet war. Das Programm konnte nicht benützt werden für solche Lösungen, bei welchen hauptsächlich das Bromidion zur Einstellung der Ionenstärke verwendet wurde, vermutlich weil die erweiterte Debye-Hückel-Gleichung unter diesen Umständen nicht anwendbar ist. Die Bildung eines Natriumphosphat-Komplexes unter normalen biologischen Konzentrationen konnte nicht nachgewiesen werden.
    Notizen: Abstract A computer program has been designed to calculate the ionic activities of calcium and orthophosphate in a wide variety of solutions. In the case of synthetic solutions the calculations were checked by comparing the computed pH values with those observed experimentally. Tests of this type with solutions having the concentrations of calcium and orthophosphate found in biological fluids and with pH values ranging from pH 3.0–10.0 indicated that the program was suitable for biological applications. The program was not effective for solutions in which the bromide ion was a principal source of ionic strength probably because of the failure of the extended Debye-Hückel equation under those circumstances. No evidence for the formation of any sodium phosphate complex at normal biological concentrations could be found.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02010149
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  • 42
    Digitale Medien
    Digitale Medien
    Analysis of otolith chemistry in Nassau grouper (Epinephelus striatus) from the Bahamas and Belize using solution-based ICP-MS (1999)
    Springer
    Coral reefs 18 (1999), S. 171-178 
    Details
    ISSN: 1432-0975
    Schlagwort(e): Key words Otolith ; Chemistry ; ICP-MS ; Stock discrimination ; Epinephelus striatus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geologie und Paläontologie
    Notizen: Abstract  We examined the utility of otolith minor and trace element chemistry, assayed with inductively coupled plasma mass spectrometry (ICP-MS), as a means of delineating population structure in the Nassau grouper (Epinephelus striatus). We characterized the elemental composition of otoliths collected in 1993 from three locations in Exuma Sound, Bahamas and from Glover Reef, Belize in 1995. A single location in Exuma Sound was sampled in 1994 to test temporal variability in otolith composition. Five elements (Ca, Zn, Sr, Ba and Pb) were routinely detected, at levels significantly above background, by solution-based ICP-MS. Results from analysis of variance of elemental data, expressed as a ratio to Ca, indicated that there were no significant differences among the Exuma locations for any element, but significant variability was found between Glover Reef and the pooled Exuma localities for Zn/Ca, Sr/Ca and Ba/Ca ratios. Significant inter-annual differences at one Exuma Sound location was restricted to Ba/Ca ratios. Discriminant function analysis correctly classified 86% and 95% of the Belize and pooled Exuma sites, respectively. Otoliths from Belize were characterized by low Zn/Ca and high Ba/Ca and Pb/Ca ratios compared to otoliths from fish collected in Exuma Sound. Although differences in Ba levels may be related to upwelling at Glover Reef, more data are needed to definitely link otolith composition with regional differences in water chemistry.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s003380050176
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  • 43
    Digitale Medien
    Digitale Medien
    The consequences of the mutual recognition of measurement standards for international metrology (2000)
    Springer
    Accreditation and quality assurance 5 (2000), S. 409-413 
    Details
    ISSN: 1432-0517
    Schlagwort(e): Key words Metrology ; Comparisons ; Chemistry ; Standards
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract  After stressing the importance in the modern world of accurate and reproducible measurements, the actions taken by the Bureau International des Poids et Mesures to set up, together with the regional metrology organizations, a series of key comparisons are described. They are the technical foundation of a mutual recognition of national measurement standards arrangement prepared in conjunction with the National Metrology Institutes (NMIs). This arrangement also includes the recognition of calibration and measurement certificates issued by these institutes. Then, the consequences of this arrangement for trade are described. The case of chemical analysis is illustrated by the application of the Kyoto protocol on the reduction of greenhouse gases. But the global workload to be taken up by the International Committee of Weights and Measures, its Consultative Committee for Amount of Substance and the NMIs is huge.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s007690000228
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  • 44
    Digitale Medien
    Digitale Medien
    Chemistry of high mountain lakes in siliceous chatchments of the Central Eastern Alps (1989)
    Springer
    Aquatic sciences 51 (1989), S. 108-128 
    Details
    ISSN: 1420-9055
    Schlagwort(e): Chemistry ; mountain lakes ; silica ; acidity ; sediment
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Alpine lakes in siliceous catchments of Tyrol and Carinthia (Austria) show signs of acidification. About 9% of the studied lakes have no alkalinity, more than 20% are below pH 6. About two thirds of all lakes have acid neutralizing capacities below 100 μeq 1−1. In spite of moderate precipitation acidity, some lakes show considerable concentrations of dissolved reactive aluminum during or shortly after snowmelt. High altitude lakes of the Alps are definitely more acidic than high mountain lakes in remote areas. Large differences in water and soil chemistry of nearby situated lakes were attributed to heterogeneities of bedrock geology. Paleolimnological investigations on former pH values of five lakes, based on diatom assemblages in the sediment, showed different developments: recent and past acidification, stable conditions, and alkalinization.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00879298
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  • 45
    Digitale Medien
    Digitale Medien
    Observations of chemical processing in the circumstellar environment (1995)
    Springer
    Astrophysics and space science 224 (1995), S. 81-84 
    Details
    ISSN: 1572-946X
    Schlagwort(e): Chemistry ; Depletions ; Shocks ; IRAS 05338-0624 ; NGC 1333 IRAS 4
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract High resolution interferometer and single-dish observations of young, deeply embedded stellar systems reveal a complex chemistry in the circumstellar environments of low to intermediate mass stars. Depletions of gas-phase molecules, grain mantle evaporation, and shock interactions actively drive chemical processes in different regions around young stars. We present results for two systems, IRAS 05338-0624 and NGC 1333 IRAS 4, to illustrate the behavior found and to examine the physical processes at work.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00667826
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  • 46
    Digitale Medien
    Digitale Medien
    Modelling the constancy of X (1994)
    Springer
    Astrophysics and space science 216 (1994), S. 153-154 
    Details
    ISSN: 1572-946X
    Schlagwort(e): Chemistry ; Molecular Hydrogen ; Cloud Models
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Observations of the CO J=1-0 line are commonly used as a tracer for molecular material in clouds. The ratio of the H2 column density to the integrated intensity of this line,X, is often taken to be constant, despite theoretical and observational uncertainty. We have tried to identify how this ratio depends on cloud parameters, testing a simple theoretical argument suggesting its invariance with respect to density. The apparent constancy can be understood if clouds are clumpy on scales of Av ≈ 1-2 mag.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00982486
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  • 47
    Digitale Medien
    Digitale Medien
    The importance of chemical data for the study of interstellar shocks (1995)
    Springer
    Astrophysics and space science 233 (1995), S. 125-137 
    Details
    ISSN: 1572-946X
    Schlagwort(e): Interstellar Medium ; Dark Clouds ; Chemistry ; Bistability ; C-shock Waves
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Shock waves perturb the chemical state of the interstellar gas. We consider the effects of C-shocks on the composition of molecular clouds, for a range of values of the pre-shock gas density and magnetic induction. The time required to re-establish equilibrium in the post-shock gas depends on the initial conditions and can become very large. The significance of the two known chemical phases of dark clouds and of bistability is considered in this context.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00627340
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  • 48
    Digitale Medien
    Digitale Medien
    Molecular diagnostics of diffusive boundary layers (1995)
    Springer
    Astrophysics and space science 233 (1995), S. 161-164 
    Details
    ISSN: 1572-946X
    Schlagwort(e): Stars ; Chemistry ; Diffusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract We have assessed the role of diffusion in determining chemical abundances in molecular interface regions. Chemical models have been developed which include the appropriate diffusion terms and that are appropriate to a narrow diffusion region (∼0.01pc) that may exist at the interface between a dark core and a hot, shocked T-Tauri wind. We have assumed pressure balance throughout and have calculated the chemical abundances as functions of time and position through the interface. The results show that significant enhancements of detectable molecules/transitions are expected (e.g. CO J=6→5, OH and CH). Using a realistic value of the diffusion coefficient a diffusive region of dimension 0.01pc may be established within about 104 years. In general it seems likely that diffusion processes are highly significant on these and smaller lengthscales.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00627344
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  • 49
    Digitale Medien
    Digitale Medien
    Turbulent mixing of reactive gases in the convective boundary layer (1997)
    Springer
    Boundary layer meteorology 85 (1997), S. 197-222 
    Details
    ISSN: 1573-1472
    Schlagwort(e): Turbulence ; Chemistry ; Closure ; Convective boundary layer
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract We study the interactions of chemistry and turbulent mixing of tracersin the convective boundary layer with a second-order closure model,including higher order chemistry terms. In order to limit the number of predictive equations we prescribe the profiles for ¯w¯Θ, ¯w¯θ ¯θ and the lengthscale l. However, for model validation we treat temperature and humidity asinert tracers, and compare the results with profiles observed during theAir Mass Transformation Experiment, and with similarity expressions for thesurface layer. We find good agreement of the mean profiles, but the (co-)variances are slightly underpredicted. Furthermore, the model usesdiagnostic equations expressing third moments of concentration in terms ofsecond moments and their vertical derivatives. They are compared withlarge-eddy model results, showing good agreement and, therefore, thesimplifications are justified. The model is applied to the transport of two gases subject to one bimolecular reaction. The importance of concentration correlations on themean transformation rate is studied. For two gases diffusing in oppositedirections we find for moderate and fast chemistry a 50% and90% decreased transformation rate due to the negatively correlatedconcentrations. These values are similar to large-eddy results of Schumannand Sykes et al. For two bottom-up tracers we find that the covariance ofboth reactive species is either positive or negative, increasing or reducingthe effective transformation rate depending on the Damköhler number (the ratio of the turbulent and the chemistry timescale). A significantdirect influence of chemistry on the flux divergence is found in bothcases. According to the model the effective transport to mid-levels of theboundary layer is increased when two reactive tracers diffuse in oppositedirections, and decreased in the case of two bottom-up tracers.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1000414710372
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  • 50
    Digitale Medien
    Digitale Medien
    Shower Meteoroids: Constraints From Interplanetary Dust Particles And Leonid Meteors (2000)
    Springer
    Earth, moon and planets 88 (2000), S. 35-58 
    Details
    ISSN: 1573-0794
    Schlagwort(e): Chemistry ; interplanetary dust particles (IDPs) ; Leonids ; meteor trails ; meteoroids ; meteors ; structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Geologie und Paläontologie , Physik
    Notizen: Abstract The cometary Leonid meteoroids represent a size range in between largest carbon-richIDPs and the smallest CI meteorites. Their dustball structure and chemistry offer anopportunity to constrain hierarchical dust accretion inferred from petrologic studies ofaggregate and cluster IDPs. The Leonid shower meteoroids of known ``comet ejection''ages provide an opportunity to study space weathering of cometary dust over periodsof up to several hundred years. The meteors and aggregate and cluster IDPs displaycontinuous thermal modification of organics and volatile element (Na, K-bearing phases), that occur as discrete minerals and amorphous solids each different response during kinetically controlled ablation. Leonid meteoroids are not excessively Na-rich. The occurrences of Leonid meteors can now be accurate predicted and combined withknowledge better models for the settling rates, collections of surviving dust becomea comet nucleus-sampling mission.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1013862627781
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  • 51
    Digitale Medien
    Digitale Medien
    Perceptions of chemistry: Why is the common perception of chemistry, the most visual of sciences, so distorted? (1996)
    Springer
    Journal of science education and technology 5 (1996), S. 193-201 
    Details
    ISSN: 1573-1839
    Schlagwort(e): Chemistry ; chemistry education ; multiple intelligences ; imagery ; visual-spatial thinking
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Allgemeine Naturwissenschaft , Technik allgemein
    Notizen: Abstract Chemistry has evolved from a science dominated by mathematics into a science highly dependent on spatial-visual intelligence. Yet the chemical content of introductory courses remains taught essentially the same as 40–50 years ago. Chemistry, today, is recognized by chemists as the molecular science. Yet, school chemistry is alienated from that perception. Thanks to the computer, young people are more comfortable with visual imaging than their instructors were at the same age. Thus the time is rife to reinvigorate chemistry education by means of the visual-spatial approach, an approach wholly in conformance with the way modern chemistry is thought about and practiced.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01575303
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  • 52
    Digitale Medien
    Digitale Medien
    Eupatorium cannabinum L. (1986)
    Springer
    Pharmacy world & science 8 (1986), S. 245-251 
    Details
    ISSN: 1573-739X
    Schlagwort(e): Analysis ; Antineoplastic agents ; Biosynthesis ; Botany ; Chemistry ; Cytotoxins ; Eupatorium cannabium ; Sesquiterpenes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract A review onEupatorium cannabinum L. is given, including botany, history and constituents. The sesquiterpene lactones are discussed in more detail, covering their biosynthesis, isolation, analysis and biological activity. Special attention is paid to the cytotoxic and antitumour activities of the sesquiterpene lactones.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01960068
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  • 53
    Digitale Medien
    Digitale Medien
    Atrial natriuretic factor: a hormone secreted by the heart (1987)
    Springer
    Pharmacy world & science 9 (1987), S. 305-314 
    Details
    ISSN: 1573-739X
    Schlagwort(e): Atrial natriuretic factor ; Blood pressure ; Chemistry ; Diuresis ; Homeostasis ; Kidney ; Muscle, smooth ; Natriuresis ; Receptors, endogenous compounds ; Renin-angiotensin system
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract It is now known that cardiac atria play an important role in blood pressure and volume regulation. Mechanical distension of the atria results in the release of a potent diuretic and natriuretic agent or agents termed the atrial natriuretic factor (ANF). Several structurally related forms of ANF exist in man and it is thought that these represent precursory forms of a single optimally active molecule and/or the presence of more than one form of active ANF. The chemical structure of ANF between different mammalian species is similar. ANF receptors have been identified in kidney, brain, vascular endothelial and smooth muscle cells, tracheal and bronchial smooth muscle and the adrenal glands of many mammalian species, including man. This would suggest that ANF influences blood pressure and volume homoeostasis by affecting any one of a number of biochemical or physiological mechanisms via different target tissues. ANF is now considered a potentially valuable therapeutic agent for the treatment of hypertension and congestive heart failure. Synthesis of potent receptor antagonists could be extremely useful in the treatment of various clinical situations which are produced or complicated by endogenously produced ANF, such as chronic orthostatic hypotension.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01956510
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  • 54
    Digitale Medien
    Digitale Medien
    Abstracts of Dutch doctoral theses (1988)
    Springer
    Pharmacy world & science 10 (1988), S. 93-95 
    Details
    ISSN: 1573-739X
    Schlagwort(e): Anthracyclines ; Chemistry ; Drug stability ; Mitomycins
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01962686
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  • 55
    Digitale Medien
    Digitale Medien
    Etoposide and teniposide (1988)
    Springer
    Pharmacy world & science 10 (1988), S. 101-116 
    Details
    ISSN: 1573-739X
    Schlagwort(e): Chemistry ; Chromatography ; Etoposide ; Immunoassay ; Metabolism ; Podophyllotoxin ; Pharmacokinetics ; Teniposide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Etoposide (VP 16-213) and teniposide (VM 26) are semisynthetic epipodophyllotoxin derivatives active against a variety of tumours. The clinical efficacy has led to an increasing interest in these compounds. This review presents information on the mechanism of action, biochemical pharmacology, bioanalysis, metabolism and pharmacokinetics of etoposide and teniposide.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01959294
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  • 56
    Digitale Medien
    Digitale Medien
    PVC as pharmaceutical packaging material (1991)
    Springer
    Pharmacy world & science 13 (1991), S. 109-118 
    Details
    ISSN: 1573-739X
    Schlagwort(e): Chemistry ; Consumer product safety ; Drug packaging ; Environmental pollution ; Plasticizers ; Polyvinyls
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract In this report the state of the art with respect to PVC as pharmaceutical packaging material is described. A general introduction into the applications of PVC is followed by a description of its production process. The metabolic effects of the monomer of PVC, vinyl chloride and of the most commonly used plasticizer diethylhexylphthalate are mentioned. Special attention is given to the pharmaceutical properties of plasticized PVC bags in comparison to other plastics and the environmental aspects of waste PVC disposal. Although there are emotional and political queries regarding the future use of PVC as a (pharmaceutical) packaging material, we conclude that there is no scientific justification for a total or partial ban of PVC. PVC will remain a fact of life as a cheap, versatile, high-performance and well-investigated plastic material for medical and pharmaceutical applications, to be replaced by newer plastics only for certain well-defined indications where the requirements of the plastic to be used are so specific that it will economically and technically be justified to use another polymer. Community and hospital pharmacists have to be prepared for a role in intake of waste plastic disposables, probably against deposit money, in order to fulfil the logistics needed for recycling.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01981526
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  • 57
    Digitale Medien
    Digitale Medien
    Progress in the research of artemisinin-related antimalarials: An update (1994)
    Springer
    Pharmacy world & science 16 (1994), S. 169-180 
    Details
    ISSN: 1573-739X
    Schlagwort(e): Antimalarials ; Artemisia annua L ; Artemisinin ; Biosynthesis ; Chemistry ; Clinical trials ; Pharmacology ; Phytochemistry ; Sesquiterpenes ; Toxicology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Artemisinin, a sesquiterpene lactone endoperoxide isolated fromArtemisia annua L., and a number of its semisynthetic derivatives have shown to possess antimalarial properties. They are all eflective againstPlasmodium parasites that are resistant to the newest and commonly used antimalarial drugs. This article gives a survey of the literature dealing with artemisinin-relaled antimalarial issues that have appeared from the end of 1989 up to the beginning of 1994. A broad range of medical and pharmaceutical disciplines is covered, including phytochemical aspects like the selection of high-producing plants, analytical procedures, and plant biotechnology. Furthermore, the organic synthesis of artemisinin derivatives is discussed, as well as their mechanism of action and antimalarial activity, metabolism and pharmacokinetics, clinical studies, sideeffects and toxicology, and biological activities other than antimalarial activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01872865
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  • 58
    Digitale Medien
    Digitale Medien
    Ultrastructural characterization by ruthenium red of the surface of the fat globule membrane of human and rat milk with data on carbohydrates of fractions of rat milk (1975)
    Springer
    Cell & tissue research 157 (1975), S. 17-24 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Milk ; Fat globule membrane ; Carbohydrates ; Chemistry ; Ruthenium red ; Ultrastructure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fat globules of the cream fractions of human and rat milk were stained with ruthenium red. Under the electron microscope, discrete granules and an amorphous coat of lesser density are seen at the surface of the milk fat globules. Since ruthenium red binds anionic groups selectively, it is probable that the granules containe the greatest concentration of these groups. The cream fraction of rat milk contains hexoses, hexosamines, methylpentoses and sialic acid. Methylpentoses and hexosamines are significantly enriched in the cream fraction. It is concluded that the finding of a surface coat in milk fat globules is in keeping with the Bargmann-Knoop model and suggests a distinct mechanism for carrying certain complex carbohydrates in milk. The role of the negative charges at the outer surface of the membrane coat in maintaining fat globules in suspension and in binding certain cations such as calcium is suggested.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00223228
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  • 59
    Digitale Medien
    Digitale Medien
    Systematics and evolution within theCompositae, seen with the eyes of a chemist (1990)
    Springer
    Plant systematics and evolution 171 (1990), S. 1-14 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Angiosperms ; Compositae ; Chemistry ; systematics ; evolution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The broad knowledge of the chemistry of theCompositae allows the discussion of its relevance for the systematics and evolution within the family. Furthermore a separation into subfamilies can be supported by the observed differences in the distribution of the main constituents in the tribes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00940593
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