Bibliothek

X
Sie haben 0 gespeicherte Treffer.
Markieren Sie die Treffer und klicken Sie auf "Zur Merkliste hinzufügen", um sie in dieser Liste zu speichern.
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
  • 1
    Digitale Medien
    Digitale Medien
    A simple regiospecific synthesis of substituted pyridines from 2-aza-1,3-dienes (1988)
    s.l. : American Chemical Society
    The @journal of organic chemistry 53 (1988), S. 5960-5963 
    Details
    ISSN: 1520-6904
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/jo00260a029
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Dissociation pathways of carbonyl halides (1989)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 93 (1989), S. 8118-8122 
    Details
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/j100361a029
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Dissociation dynamics of low-lying electronic states of SiH2 (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 88 (1988), S. 2334-2341 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Essential features of the potential surfaces for low-lying electronic states of silylene, SiH2, have been characterized. Calculated transition energies between the X˜ 1A1, a˜ 3B1, and A˜ 1B1 states are in agreement with previously published experimental and theoretical values. The reactions Si(1D)+H2 and SiH(2Π)+H2 leading to SiH2(X˜ 1A1) appear to be barrierless processes. On the a˜ 3B1 and A˜ 1B1 surfaces, asymmetric transition states are found for SiH2 dissociation. The activation energy for dissociation, SiH2(a˜ 3B1)→Si(3P)+H2(1Σ+g), is calculated to be 44.7 kcal/mol, and the dissociation energy for SiH2(X˜ 1A1)→Si(1D)+H2(1Σ+g) is calculated to be 65.8 kcal/mol. Structures and vibrational frequencies are presented for the low-lying electronic states of SiH2 and for the associated transition states. Lifetimes of individual rovibronic levels of SiH2(A˜ 1B1) are found to decrease dramatically in v'2 =8 as compared with v2 =7. This lifetime shortening is attributed to the opening of the dissociation channel to Si(1D)+H2(1Σ+g) which establishes the relative energies of SiH2 and Si+H2. From these relative energies ΔH(open circle)f(298) and SiH2 is determined to be 63.6±2.8 kcal/mol.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.454069
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Dissociation dynamics of FCO and HCO radicals (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 3044-3049 
    Details
    ISSN: 1089-7690
    Quelle: AIP Digital Archive
    Thema: Physik , Chemie und Pharmazie
    Notizen: Dissociation energies and barriers to dissociation for XCO→X+CO have been calculated for X˜ 2A' and A˜ 2π states of FCO and HCO by ab initio molecular orbital methods. At the PUMP4//UMP2/6-311G* level, D(open circle)298 (F-CO)=22.3 kcal mol−1 and ΔH298=24.2 kcal mol−1 for dissociation of ground-state FCO; these values are much higher than the corresponding bond energy and activation enthalpy for HCO dissociation. Calculated RRKM rate constants suggests that the lifetime of FCO under stratospheric conditions is sufficient to allow bimolecular reactions to compete with dissociation. Reaction with O2 may provide an in situ source of stratospheric CO2.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.454959
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Lipid Metabolism in Electroplax (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 49 (1987), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: The in vivo labeling of electrocyte lipids is followed after injection of radioactive glycerol and two fatty acids, oleate and arachidonate, into the electric organ of an elasmobranch (Discopyge tschudii). De novo synthesis of lipids and acyl-exchange reactions are operative in the electrocyte. The three precursors are preferentially incorporated into phosphatidylcholine, phosphatidylinositol, and triacylglycerols. The highest specific activities are attained by triacylglycerols and polyphosphoinositides. Electrocyte stacks from electric organ show an efficient and continuous esterification of oleate and arachidonate into lipids after several hours of incubation. Except for an apparently more active labeling of triacylglycerols, which is attributed to the larger availability of free fatty acid precursors under the in vitro experimental conditions, the pattern of lipid labeling is similar to that attained in vivo. 32P-labeled lipids are also steadily produced in electrocyte stacks (24 h of incubation with [32P]phosphate) using glucose as the sole exogenous source of energy. Polyphosphoinositides are the lipids preferentially labeled. The ability to sustain the labeling of lipids under in vitro conditions renders isolated electrocyte stacks an interesting model for future research on lipid involvement in cholinergic function.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1987.tb00997.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Composition of Lipids in Elasmobranch Electric Organ and Acetylcholine Receptor Membranes (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 49 (1987), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: The composition of phospholipids from electric organ and from membranes enriched in acetylcholine receptors (AChRs) is analyzed in three elasmobranch fish (Torpedo marmorata, Torpedo californica, and Discopyge tschudii). Irrespective of their purity, AChR-containing membranes are similar to electric organ in lipid and fatty acid composition. The following characteristics are common to the three species: (a) Choline, ethanolamine, and serine glycerophospholipids account for 80–90% of the phospholipids. (b) Their major fatty acid constituents are monoenes, saturates, and long-chain (n-3) polyenes (especially docosahexaenoate). (c) A large proportion of (he ethanolamine glycerophospholipids (30–50%) is made up by plasmenylethanolamine, which contains fewer polyenes than phosphatidylethanolamine per mole of lipid. (d) Poly-phosphoinositides represent 20–30% of the inositides of electric organ, (e) Phosphatidylinositol and phosphatidate have large proportions of 20-and 22-carbon polyenes. (f) Diphosphatidylglycerol and triacylglycerols are rich in oleate but also contain long-chain polyenes. (g) Sphingo-myelin has monoenes and saturates ranging from 14 to 26 carbons. Species-related variations are observed (a) in the ratios between some phospholipid classes and subclasses and (b) in the relative abundance of the major polyunsatu-rated acyl chains of phospholipids. Despite these differences, the average unsaturation and length of fatty acids in major phospholipid classes are similar for the three species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1987.tb00996.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Asymmetry of Diacylglycerol Metabolism in Rat Cerebral Hemispheres (1986)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of neurochemistry 46 (1986), S. 0 
    Details
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: Diacylglycerols (DGs) were found to be asymmetrically distributed between the two cerebral hemispheres of rat brain. The left cerebral hemisphere (LCH) contained 100% more DG than the right cerebral hemisphere (RCH). The lateralization was enhanced in animals subjected to depolarization induced by a single electroconvulsive shock (ECS). During the acute phase of the convulsion, the DG pool increased in both hemispheres, with the LCH attaining a concentration 180% higher than the RCH. Stearate and arachidonate were the principal DG-acyl groups accumulated in the RCH, whereas in the LCH stearate and palmitate were mainly involved. After the last of a series of five shocks (one per day) the laterialization of the “DG response’ was less accentuated during the acute phase of the ECS. Whereas DG release was drastically reduced in the LCH, in the RCH it was minimally affected. The DG sidedness after five shocks was nevertheless maintained at the level of arachidonate-containing DGs, which showed a higher accumulation in the LCH than in the RCH. The kinetics of DG removal showed a rapid phase during the first minute following a single or five ECSs. Total DG levels returned to basal values in the RCH, whereas in the LCH they remained slightly increased with respect to the initial levels 1 min after the convulsive episode. Minimal changes occurred in the subsequent 4 min. Chronic ECS altered the endogenous DG content and composition. Thus, 24 h after the last of four ECSs, total levels of DGs diminished by 40% in the RCH, whereas they remained unchanged in the LCH. The asymmetry in the basal levels between hemispheres was therefore accentuated. with the LCH containing 160% more DG than the RCH. These results suggest the lateralization of biochemical events involved in DG metabolism in rat cerebral hemispheres, both under basal conditions and after electrical stimulation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1471-4159.1986.tb01751.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Macro and micro rate zonal analytical centrifugation of polydisperse and slowly diffusing sedimenting systems in isovolumetric density gradients. Application to cartilage proteoglycans (1989)
    s.l. : American Chemical Society
    Biochemistry 28 (1989), S. 5276-5282 
    Details
    ISSN: 1520-4995
    Quelle: ACS Legacy Archives
    Thema: Biologie , Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/bi00438a053
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Stabilization of a sodium channel state with high affinity for saxitoxin by intramolecular cross-linking. Evidence for allosteric effects of saxitoxin binding (1988)
    s.l. : American Chemical Society
    Biochemistry 27 (1988), S. 2389-2397 
    Details
    ISSN: 1520-4995
    Quelle: ACS Legacy Archives
    Thema: Biologie , Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/bi00407a021
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Mixing liquids in microseconds (1985)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 56 (1985), S. 283-290 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: An instrument is described in which two solutions can be homogeneously mixed within several microseconds. The liquids flow separately through two coaxial capillaries with conical tips and then simultaneously around a sphere (50–100 μ in diameter) which has been positioned close to the end of the outer tip. The liquids flow with velocities of ∼100 m/s through the small passages (∼5 μ wide) separating the sphere and the wall of the outer capillary and mix in the turbulent liquid flow behind the sphere. The mixed liquids are then ejected as a narrow liquid jet for observation. Design characteristics and construction techniques are presented along with a discussion of the properties of the turbulent flow field and estimates of the expected practically realizable mixing times. The experimentally determined speed of mixing indicates that we have nearly achieved the proposed lower limits of the mixing time.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1138345
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...