ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • 1995-1999  (71)
  • 1930-1934
Collection
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 7753-7755 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1432-1041
    Keywords: Key words Nisoldipine ; Hypertension; Ca antagonist ; pharmacokinetics ; pharmacodynamics ; PK/PD modelling
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Nisoldipine, a calcium antagonist of the dihydropyridine class, has been used in the treatment of hypertension and angina pectoris. A new controlled-release dosage form (nisoldipine coat-core, NCC) has been developed to allow once daily dosing. In addition to a formal food interaction study as requested by regulatory authorities for controlled-release dosage forms, a subsequent study was conducted to determine the clinical relevance of the changes in nisoldipine plasma concentration vs time profiles seen in the food effect study. Methods: After a placebo run-in phase of 6 days, 12 hypertensive patients started treatment with 20 mg NCC once daily (days 0–3, 5–6, 8–9). On days 4, 7 and 10 the NCC was substituted for 5, 10 and 20 mg nisoldipine solution, respectively, in order to obtain nisoldipine plasma concentration vs time profiles comparable to the ones resulting from the concomitant intake of food and NCC. Simultaneous measurements of blood pressure (BP) and nisoldipine concentration were performed on days 3, 4, 7 and 10. Results: The relationship between nisoldipine plasma concentrations and percentage reduction in BP [diastolic (DBP) and systolic (SBP), supine and standing] could be described by an Emax model. The mean maximum reduction (Emax) relative to baseline was about 36.4% and 37.7% (DBP, supine and standing) and 27.9% and 29.2% (SBP, supine and standing), respectively. The interindividual variability (% CV) in Emax was low, ranging from 17.6% to 28.8%. The mean nisoldipine plasma concentration corresponding to 50% of the maximum effect (EC50) ranged between 0.99 and 2.62 μg · l–1 with a pronounced interindividual variability (% CV) of 89.5–108.8%. Mean Cmax values after administration of the 30 and 40 mg NCC together with food were 4.5 and 7.5 μg · l–1, respectively. Based on the concentration-effect relationship established in the present study, the effect achieved with a concentration of 7.5 μg · l–1 will be about 77% of Emax for DBP and about 88% of Emax for SBP, respectively. Conclusion: At the time of maximum plasma concentration the additional decrease in BP relative to baseline due to the food effect will be about 7–15% for DBP and 3–9% for SBP. After administration of the 10␣mg solution with a mean Cmax of 8.7 μg · l–1, only headache and flush with mild severity have been reported as adverse events. These maximum concentrations are comparable to Cmax values seen after intake of 40 mg NCC with food. With regard to heart rate (HR) there were distinct differences between the two formulations: Following administration of 5, 10 and 20 mg nisoldipine solution, there were dose-dependent increases in HR by a maximum of 4, 12 and 16 beats · min−1, respectively, whereas the HR profile for the NCC was similar to that seen under placebo treatment.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Il nuovo cimento della Società Italiana di Fisica 17 (1995), S. 1753-1757 
    ISSN: 0392-6737
    Keywords: Brillouin and Rayleigh scattering ; Polaritons (including photon-phonon and photon-magnon interactions) ; Electron states in low-dimensional structures (including quantum wells, superlattices, layer structures and intercalation compounds) ; Conference proceedings
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary Resonant Brillouin scattering in ultrathin MBE-grown epitaxial layers of ZnSe with thicknesses from 50 to 200 nm is esployed to investigate the properties of the 1s exciton-polariton states. The effective masses are found different from that in bulk ZnSe caused by the energetic decoupling of heavy- and light-hole states due to strain. In the 50 nm sample the momentum selection rule is relaxed, leading to broad Brillouin lines that show fine structure due to the phonon quantization in these layers, whereby dilatation and flexural phonon modes are involved in the scattering.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 5143-5145 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In order to study the influence of the nanocrystalline microstructure on the magnetic properties of pure nanocrystalline metals, in situ magnetic measurements of high-purity nanocrystalline nickel, prepared by a gas-condensation technique with subsequent compaction at various pressures have been performed. The approach to ferromagnetic saturation indicates free volumes in the nanocrystalline system of the size of individual missing crystallites as well as internal stresses. While the saturation polarization of the nanocrystalline Ni samples appears to be unchanged compared to coarse-grained Ni the coercive field and magnetic domains are strongly influenced by the nanocrystalline structure. The shape of the domains with sizes of 10–200 μm much larger than the crystallite size depends on the annealing state of the specimen. The initial coercive field increases with the compaction pressure during preparation. Upon annealing it further increases to a maximum value at Ta=500 °C and decreases at higher annealing temperatures. Additionally, the effect of oxygen located in the grain boundaries has been studied. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 80 (1996), S. 724-728 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In order to study the formation of thermal vacancies in the Ti–Al alloy system, high-temperature positron lifetime measurements together with a modeling of defect formation in the framework of nearest-neighbor pair bonds were performed for α2Ti3Al and compared to recent results on γTiAl [U. Brossmann, R. Würschum, K. Badura, and H.-E. Schaefer, Phys. Rev. B 49, 6457 (1994)]. Substantial increases of the positron lifetime τ were observed for Ti65.6Al34.4 and Ti77.1Al22.9 in the temperature range T(approximately-greater-than)1200 K where thermal vacancy concentrations above the detection limit of positron annihilation are expected from the model calculations for the α2 phase. Within the high-temperature increase of the positron lifetime in the α2 and the β phase single-component positron lifetime spectra were observed. This behavior is in contrast to the two-component spectra observed conventionally at intermediate positron trapping rates and is attributed to a fast detrapping and retrapping of positrons at vacancies due to a low positron–vacancy binding energy. For this case, a vacancy formation enthalpy of HFV=(1.55±0.2) eV in α2Ti65.6Al34.4 and HFV=(1.8±0.2) eV in βTi77.1Al22.9 can be derived. These results are discussed in the context of recent 44Ti tracer diffusion studies. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Cambridge, MA, USA : Blackwell Science, Inc.
    Restoration ecology 6 (1998), S. 0 
    ISSN: 1526-100X
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The ataxonomic phytoplankton composition and abundance (biomass classes) in lakes of differing acidity were examined by flow cytometry. The ataxonomic parameters applied here were photosynthesis pigments and cellular protein content. Up to 1000 cells per second can be assessed by this method. Consequently, enough cells to create biomass spectra can be counted within only a few minutes. Photosynthesis pigment autofluorescence was used to separate algal cells from detritus and to classify the phytoplankton organisms into different pigment groups. Chlorophyll fluorescence ratio (CFR) at different excitation wave lengths proved to be a sensitive tool. As expected, the diversity of CFR-determined pigment groups decreased with increasing acidification. Some groups were acid-insensitive and occurred even at pH below 3.0. However, picoplanktic cyanobacteria (Synechoccocus/Synechocystis-like particles [SLPs]) were absent at pHs below 4.5–4.0, with their accompanying high metal concentrations. Thus, the reappearance of cyanobacterial picoplankton may serve as a first major restoration goal in strongly acidified lakes. Protein staining using fluorescein isothiocyanate enables fast estimates of phytoplankton biomass and establishment of biomass spectra as an estimate of the integrity of plankton communities. Although the phytoplankton investigations presented are only snapshots of the situation on the sampling days, the feasibility of flow cytometrical methods for preparing phytoplankton biomass spectra has been demonstrated. The completeness of such biomass spectra, such as the presence or absence of SLP-picoplankters, as well as the variances around regression lines (linear or parabolic), may serve as goals in restoring lakes acidified to different degrees.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 363 (1999), S. 300-305 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Different acid compositions (HNO3, H2O2, HF and HClO4) and low pressure microwave digestion were applied to the microwave assisted dissolution of ancient peats. The digests were evaluated with respect to the decomposition of the inorganic and organic fraction of peats and to an optimised determination of Pb by differential pulse anodic stripping voltammetry (DPASV). Addition of hydrofluoric acid was necessary to achieve a complete dissolution of the resistant inorganic phase of the peat and to obtain the total Pb concentration. Addition of perchloric acid decreased the concentration of dissolved organic carbon significantly, enabling reliable voltammetric signals for Pb determinations with satisfying peak shape, baseline, sensitivity, and precision. The limit of detection for Pb in peats was 1 ng/mL in the acid digest, equivalent to 0.2 μg/g in solid peat. This allowed the determination of low, pre-industrial concentrations of Pb in peat bogs from various locations (Europe and SE Asia). A chelation column used to isolate the metals from the complex matrix to further improve the detection limits failed to provide good recoveries for the peats and plants.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Fresenius' journal of analytical chemistry 364 (1999), S. 565-569 
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract To establish an electrochemical HPLC detection system which is suitable for the voltammetric characterisation of unknown contaminants and food components at working potentials lower than –1 V, a modified flow-through cell for the use of a hanging mercury drop electrode (HMDE) is described. The introduction of silanised glass capillaries and a new flow-channel design provide a high HMDE lifetime, which is recommended in HPLC detection. As test system the herbicides diquat, paraquat and difenzoquat and ethylviologen as internal standard were measured using differential pulse voltammetry (DPV) detection to improve selectivity. Spiked water samples were analysed with voltammetric and UV-detection and results agreed well.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Applied microbiology and biotechnology 45 (1996), S. 342-348 
    ISSN: 1432-0614
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract  The transformation of oleic acid by mutants of Candida tropicalis was studied in fed-batch cultures. Besides Δ9-cis–1,18-octadecenedioic acid, 3-hydroxy-Δ9-cis–1,18-octadecenedioic acid was detected as the main fermentation product. Here we describe the production, isolation and the complete chemical characterization of the purified 3-hydroxy-Δ9-cis–1,18-octadecenedioic acid. The geometric configuration of the double bond was not changed during bioconversion. The enantiomeric excess of the compound was 76%. Mutagenesis of C. tropicalis DSM 3152 with N-methyl-N-nitro-N′-nitrosoguanidine and selection with oleic acid as the sole carbon source led to mutant M 25, which produced the 3-hydroxy-Δ9-cis–1,18-octadecenedioic acid at a 1.8-fold higher concentration in the medium as compared to the parent strain. The maximum concentration of the hydroxy dioic acid was 19.4 g/l after 223 h fermentation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Monatshefte für Chemie 126 (1995), S. 341-347 
    ISSN: 1434-4475
    Keywords: Chloroacetic acid chloride ; Phenylhydrazono acetamides ; Pyridines ; Pyridazin-5-ylpyridinium chlorides ; 4,5-Diamino-pyridazin-6(1H)-ones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Arylhydrazono acetamides1 react with chloroacetic acid chloride to give N-chloroacetyl derivatives2. Subsequent reaction with pyridines followed by ring closure yield 1-(4-amino-6-oxo-pyridazin-5-yl)-pyridinium chlorides3. Analogously, 1-(6-oxo-pyridazin-5-yl)-pyridinium chloride (5) and 6-oxo-5-pyridinio-pyridazin-4-olate (4) are formed from phenylhydrazono derivatives and pyridine. Treatment of3 and4 with hydrazinium hydrate gives 4,5-diamino-6-oxo-pyridazin-3-carbohydrazides6 and 5-amino-4-hydroxy-pyridazin-6(1H)-one (8). An analogous ring cleavage of3e and5 gives rise to 4,5-diamino- and 5-amino-pyridazin-6(1H)-ones7. On treatment of the pyridinium salts3 with caustic soda in water, nucleophilic addition of the amino group to the pyridinium ring takes place and stable dehydrated products9 are isolated.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...