ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
Filter
  • Artikel  (7)
  • Chemistry  (5)
  • Mice  (2)
  • Astronomy
  • METEOROLOGY AND CLIMATOLOGY
  • SPACECRAFT DESIGN, TESTING AND PERFORMANCE
  • 1990-1994  (7)
  • 1
    Digitale Medien
    Digitale Medien
    Reexamination of the polymerization of pyridoxylated hemoglobin with glutaraldehydeThe opinions or assertions contained herein are the private views of the authors, and are not to be construed as official or as reflecting the views of the Department of the Army or the Department of Defense. (1990)
    New York : Wiley-Blackwell
    Biopolymers 29 (1990), S. 871-882 
    Details
    ISSN: 0006-3525
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Pyridoxylated adult human hemoglobin (HbAo) was prepared using a one molar equivalent of pyridoxal 5-phosphate (PLP) per heme and reduced with either NaCNBH3 or NaBH4. A separate sample was pyridoxylated and passed through a mixed-bed ion exchange column without reduction. All three preparations had a P50 of 29 ± 2 torr and a cooperativity of n = 2.4 ± 0.1. These preparations, in both the oxy and deoxy forms, were then treated with 7 equivalents of glutaraldehyde per tetramer at pH 6.8 at 4°C and at room temperature. The polymerization invariably reduced the P50 to 18 ± 2 torr with Hill coefficients of less than 2. These solutions, with or without further reduction using NaCNBH3, all retained the PLP in differing amounts (2-3 moles/tetramer). Methemoglobin concentrations were increased during the polymerization reaction. The normal pyridoxylation procedure, using sodium borohydride reduction, resulted in a number of different molecular species. Polymerization with glutaraldehyde caused a further proliferation of molecular species that could not be separated by anion exchange chromatography or by isoelectric focusing. The extent of polymerization, estimated by gel exclusion chromatography and SDS polyacrylamide gel electrophoresis, was from 40 to 50%. Analysis of the reverse phase chromatograms, which separate the heme and the α- and β-chains, showed extensive polymerization and distribution of the radioactively labeled PLP on the protein for all preparations. All of the polymerized and pyridoxylated samples were unstable, and showed different chromatographic patterns after storage at 4°C for 1 month. Attempts to stabilize these preparations by further reduction with NaCNBH3 gave products with a lower P50 and lower cooperativity. When the reactions were conducted with a purified HbAo, heterogeneity was somewhat decreased compared to the normally used stroma-free hemoglobin, but a large number of molecular species were still formed.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/bip.360290602
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Physical and mechanical properties of highly plasticized pectin/starch films (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 54 (1994), S. 1311-1320 
    Details
    ISSN: 0021-8995
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Maschinenbau , Physik
    Notizen: Blends of citrus pectin and high amylose starch plasticized with glycerine were investigated to determine the effect of compositional variables on film properties. Several films with representative compositions were made from sugar beet and almond pectin, and tested for comparison. The films were cast from water onto glass plates, dried, and removed. Mechanical analysis was done using a Rheometrics RSA II solids analyzer. Increasing the glycerine concentration led to decreases in static modulus, dynamic modulus, and tensile strength, but to increases in elongation. Increasing levels of starch in the blend lowered the effect of glycerine on mechanical properties. Oxygen permeability of the films was extremely low. Sugar-beet pectin and almond pectin gave films with mechanical properties comparable to those made with citrus pectin. © 1994 John Wiley & Sons, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/app.1994.070540913
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    The effect of anodic surface treatment on the oxidation of catechols at ultrasmall carbon ring electrodes (1991)
    Weinheim : Wiley-Blackwell
    Electroanalysis 3 (1991), S. 899-907 
    Details
    ISSN: 1040-0397
    Schlagwort(e): Microelectrodes ; electrochemical treatment ; carbon ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Electrochemical anodic treatment at ultrasmall carbon ring electrodes appears to result in the formation of an oxide film that displays charge-selective and pH-dependent enhancements following treatment. Voltammetry after treatment in pH 7.4 citrate-phosphate buffer is more Nernstian for dopamine (DA) and less Nernstian for 3,4-dihydroxyphenylacetic acid (DOPAC). However, oxidation in pH 2.8 buffer gives rise to voltammetry that is less Nernstian for both DA and DOPAC. Extensive surface oxidation in potassium hydroxide apparently forms a thick layer that acts like a thin layer reservoir for adsorbed analyte. Voltammetry following extensive treatment is attenuated and peak shaped. Minimal surface oxidation in KOH results in more Nernstian sigmoidal voltammetry with only light current attenuation. The data suggest that an oxide layer formed following anodic treatment is non-uniform and leaves sites of activated carbon exposed on the surface. Furthermore, it appears that this layer has cation-exchange properties giving rise to charge transfer selectivity. A model of the surface formed following anodic oxidation is consistent with previous models involving both surface cleanliness and carbon structure orientation.
    Zusätzliches Material: 7 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/elan.1140030905
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Oral toxicity to flesh flies of a neurotoxic polypeptide (1992)
    New York, NY [u.a.] : Wiley-Blackwell
    Archives of Insect Biochemistry and Physiology 21 (1992), S. 41-52 
    Details
    ISSN: 0739-4462
    Schlagwort(e): polypeptide neurotoxin ; gut permeability ; Sarcophaga falculata ; Chemistry ; Food Science, Agricultural, Medicinal and Pharmaceutical Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Biologie
    Notizen: An insect selective neurotoxic polypeptide from venom of the scorpion Androctonus australis (AalT, Mr 8,000) was shown to cross the midgut of the flesh fly Sarcophaga falculata, using assays of oral toxicity, column chromatography, and microscopic autoradiography of the native and radioiodinated toxin. AalT induced paralysis of flies within 1-2 h after oral administration, with a lethal dose (LD50) of 10 μg/100 mg of body weight. Oral toxicity was about 0.14% of toxicity by injection. Hemolymph collection 70-85 min after feeding flies with [125l]AalT showed that 5% of ingested radioactivity appeared in hemolymph. Most of this represented degradation products, but included about 0.3% of the chromatographically intact toxin. In contrast, hemolymph of identically treated lepidopterous larvae (Manduca, Helioverpa [=Heliothis]) contained degradation products but no intact toxin. [125l]AalT was shown to cross the midgut of Sarcophaga through a morphologically distinct segment of the midgut previously shown to be permeable to a cytotoxic, positively charged polypeptide of similar molecular weight. These results suggest that Sarcophaga midgut contains a morphologically and functionally distinct segment that transports small peptides, and that employment of neurotoxic polypeptides for insect control may be feasible. Activity might be greatly improved through modification and metabolic stabilization of active peptides. © 1992 Wiley-Liss, Inc.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/arch.940210105
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    New possibilities of overlapping Raman band resolution by methods of CARS spectroscopy (1994)
    Chichester [u.a.] : Wiley-Blackwell
    Journal of Raman Spectroscopy 25 (1994), S. 267-273 
    Details
    ISSN: 0377-0486
    Schlagwort(e): Chemistry ; Analytical Chemistry and Spectroscopy
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: New possibilities for the resolution of Raman bands, provided by polarization-sensitive CARS in combination with a phase-mismatching technique, are presented. The use of this combination of techniques allows one to achieve the most informative spectra and resolve the complex structure of inhomogeneously broadened contours. The variation of the resonant/non-resonant ratio using a phase-mismatching technique and the special possibilities of polarization CARS spectroscopy in lineshape formation are used. The results of an investigation of a cyclohexane and naphthalene mixture and of n-pentane by polarization CARS in combination with a phase-mismatching technique are presented.
    Zusätzliches Material: 9 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/jrs.1250250405
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    facet.materialart.
    Unbekannt
    Effects of cerebral ischemia in mice deficient in neuronal nitric oxide synthase (1994)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1994-09-23
    Beschreibung: The proposal that nitric oxide (NO) or its reactant products mediate toxicity in brain remains controversial in part because of the use of nonselective agents that block NO formation in neuronal, glial, and vascular compartments. In mutant mice deficient in neuronal NO synthase (NOS) activity, infarct volumes decreased significantly 24 and 72 hours after middle cerebral artery occlusion, and the neurological deficits were less than those in normal mice. This result could not be accounted for by differences in blood flow or vascular anatomy. However, infarct size in the mutant became larger after endothelial NOS inhibition by nitro-L-arginine administration. Hence, neuronal NO production appears to exacerbate acute ischemic injury, whereas vascular NO protects after middle cerebral artery occlusion. The data emphasize the importance of developing selective inhibitors of the neuronal isoform.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Huang, Z -- Huang, P L -- Panahian, N -- Dalkara, T -- Fishman, M C -- Moskowitz, M A -- NS10828/NS/NINDS NIH HHS/ -- NS2636/NS/NINDS NIH HHS/ -- New York, N.Y. -- Science. 1994 Sep 23;265(5180):1883-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Stroke Research Laboratory, Massachusetts General Hospital, Charlestown 02129.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7522345" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Oxidoreductases/antagonists & inhibitors/deficiency/*metabolism ; Animals ; Arginine/analogs & derivatives/pharmacology ; Brain/enzymology/*metabolism ; Brain Ischemia/complications/*metabolism ; Cerebral Infarction/*etiology ; Cerebrovascular Circulation ; Female ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Mutation ; Neurons/*enzymology ; Nitric Oxide/*metabolism ; Nitric Oxide Synthase ; Nitroarginine
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
  • 7
    facet.materialart.
    Unbekannt
    Endothelial NOS and the blockade of LTP by NOS inhibitors in mice lacking neuronal NOS (1994)
    American Association for the Advancement of Science (AAAS)
    Details
    Publikationsdatum: 1994-07-22
    Beschreibung: Long-term potentiation (LTP) is a persistent increase in synaptic strength implicated in certain forms of learning and memory. In the CA1 region of the hippocampus, LTP is thought to involve the release of one or more retrograde messengers from the postsynaptic cell that act on the presynaptic terminal to enhance transmitter release. One candidate retrograde messenger is the membrane-permeant gas nitric oxide (NO), which in the brain is released after activation of the neuronal-specific NO synthase isoform (nNOS). To assess the importance of NO in hippocampal synaptic plasticity, LTP was examined in mice where the gene encoding nNOS was disrupted by gene targeting. In nNOS- mice, LTP induced by weak intensity tetanic stimulation was normal except for a slight reduction in comparison to that in wild-type mice and was blocked by NOS inhibitors, just as it was in wild-type mice. Immunocytochemical studies indicate that in the nNOS- mice as in wild-type mice, the endothelial form of NOS (eNOS) is expressed in CA1 neurons. These findings suggest that eNOS, rather than nNOS, generates NO within the postsynaptic cell during LTP.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉O'Dell, T J -- Huang, P L -- Dawson, T M -- Dinerman, J L -- Snyder, S H -- Kandel, E R -- Fishman, M C -- DA-00074/DA/NIDA NIH HHS/ -- DA-00266/DA/NIDA NIH HHS/ -- MH-45923/MH/NIMH NIH HHS/ -- etc. -- New York, N.Y. -- Science. 1994 Jul 22;265(5171):542-6.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Howard Hughes Medical Institute, College of Physicians and Surgeons of Columbia University, New York, NY 10032.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/7518615" target="_blank"〉PubMed〈/a〉
    Schlagwort(e): Amino Acid Oxidoreductases/antagonists & inhibitors/genetics/*metabolism ; Animals ; Arginine/*analogs & derivatives/pharmacology ; Electric Stimulation ; Endothelium/enzymology ; Hippocampus/drug effects/enzymology/*physiology ; In Vitro Techniques ; *Long-Term Potentiation/drug effects ; Mice ; Mutation ; Nitric Oxide/*metabolism ; Nitric Oxide Synthase ; Nitroarginine ; Pyramidal Cells/drug effects/enzymology/*physiology ; Synaptic Transmission/drug effects
    Print ISSN: 0036-8075
    Digitale ISSN: 1095-9203
    Thema: Biologie , Chemie und Pharmazie , Informatik , Medizin , Allgemeine Naturwissenschaft , Physik
    Publiziert von American Association for the Advancement of Science (AAAS)
    Standort Signatur Erwartet Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    AKTUELLE ARTIKEL
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...