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1.
The C4'-oxidized abasic site (C4-AP) is produced by a variety of DNA damaging agents. This alkali labile lesion can exist in up to four diastereomeric cyclic forms, in addition to the acyclic keto-aldehyde. Synthetic oligonucleotides containing the lesion were prepared from a stable photochemical precursor. Chemical integrity of the lesion containing oligonucleotides was probed using phosphodiesterase lability. Analysis of the 3',5'-phosphate diester of the monomeric lesion released from single diastereomers of photolabile precursors by 1H NMR indicates that isomerization of the hemiacetal and/or hemiketal is rapid. The syntheses and characterization of oligonucleotides containing configurationally stable analogues of C4-AP, which serve as mechanistic probes for deciphering the structural basis of the biochemical and biological effects of the C4'-oxidized abasic lesion, are also described. 相似文献
2.
Background
Growth hormone (GH) plays an incompletely understood role in the development of the central nervous system (CNS). In this study, we use transgenic mice expressing a growth hormone antagonist (GHA) to explore the role of GH in regulating postnatal brain, spinal cord and body growth into adulthood. The GHA transgene encodes a protein that inhibits the binding of GH to its receptor, specifically antagonizing the trophic effects of endogenous GH. 相似文献3.
A Mukherjee M Dasgupta DJ Hinde CR Morton AC Berriman RD Butt JO Newton H Timmers 《Pramana》2001,57(1):195-198
Fusion cross-sections for the 7Li + 12C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy
evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their
contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections
due to the breakup of 7Li may not be significant for 7Li + 12C reaction at energies around the barrier. 相似文献
4.
Roads less traveled: Nitrogen reduction reaction catalyst design strategies for improved selectivity
Bianca M. Ceballos Ghanshyam Pilania Kannan P. Ramaiyan Amitava Banerjee Cortney Kreller Rangachary Mukundan 《Current Opinion in Electrochemistry》2021
Direct electrochemical nitrogen reduction for ammonia production is necessary to reduce the use of fossil fuels from conventional Haber–Bosch methods. Applications of nitrogen reduction electrocatalysts remain inhibited by slow reaction kinetics and low faradaic efficiencies because of competitive H2 production pathways. Current strategies to address this challenge in selectivity have focused on catalyst design, reactor configuration, and electrolyte conditions. This brief review discusses the thermodynamic and kinetic challenges in the field as well as current underused approaches for selective catalyst development including bimetallic catalysts, transition metal nitrides, and carbon supports. 相似文献
5.
Background
The 5-HT3 receptor is a member of a neurotransmitter-gated ion channel family which includes nicotinic acetylcholine, GABAA, and glycine receptors. While antibodies specific for the 5-HT3A receptor subunit are plentiful, and have revealed a wealth of structural and functional information, few antisera exist for the detection of 5-HT3B receptor subunits. Here we describe the generation and characterisation of a rabbit polyclonal antiserum that specifically recognises 5-HT3B receptor subunits 相似文献6.
The reactivity of the 2,2′-, 2,4′-, 4,4′-dibenzyldiisocyanate (2,2′-, 2,4′-, 4,4′-DBDI) with n-butanol in benzene has been studied. The concentrations of all species were monitored by using high performance liquid chromatography (HPLC). The reactivity of 4,4′-DBDI is similar to that of 4,4′-diphenylmethanediisocyanate (4,4′-MDI). Very strong intramolecular catalytic effects were noticed in the case of 2,2′-DBDI, probably due to the variable molecular geometry. These effects are responsible for the whole reaction pattern. The 2,4′-DBDI NCO ortho and para groups reactivities are different and comparable to that of 2,4-toluylenediisocyanate (2,4-TDI). 相似文献
7.
Dipl.-Ing. H. Kreller Dr.-Ing. A. Rubert 《Archive of Applied Mechanics (Ingenieur Archiv)》1984,54(1):62-72
Übersicht Es wird ein analytisches Lösungsverfahren zur Integration der Kirchhoffschen Plattendifferentialgleichung für die unendlich ausgedehnte Vollplatte unter konstanter Flächenlast angegeben. Sie ist in einem regelmäßigen quadratischen oder rechteckigen Raster längs kreisrunder Stützenaussparungen gelagert (Lochrandlagerung). Die Randbedingungen der gelenkigen Lagerung am Lochrand (Stützbereich) werden exakt befriedigt, während die Symmetriebedingungen in den Feldmitten punktweise erfüllt werden. Numerische Untersuchungen zeigen die hohe Genauigkeit der Lösung.
Analytical solution, with boundary collocation, of Kirchhoff's differential equation for the infinitely extended solid plate with articulated hole edge support
Summary An analytical solution for the integration of Kirchhoff's differential equation for the infinitely extended solid plate subject to constant surface loading is described. The plate is simply supported on the edges of circular holes arranged on a regular square or rectangular grid (hole edge support). The boundary conditions of articulated support on the hole edge (support area) are exactly satisfied, while the symmetry conditions in the centre of the panels are met at points. Numerical analyses indicate a high degree of accuracy of the solution.相似文献
8.
Lawrence CR Tafoya C William Shuttleworth Yuchio Yanagawa Kunihiko Obata Michael C Wilson 《BMC neuroscience》2008,9(1):105
Background
The soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) complex, comprised of SNAP-25, syntaxin 1A, and VAMP-2, has been shown to be responsible for action potential (AP)-dependent, calcium-triggered release of several neurotransmitters. However, this basic fusogenic protein complex may be further specialized to suit the requirements for different neurotransmitter systems, as exemplified by neurons and neuroendocrine cells. In this study, we investigate the effects of SNAP-25 ablation on spontaneous neuronal activity and the expression of functionally distinct isoforms of this t-SNARE in GABAergic and glutamatergic neurons of the adult brain. 相似文献9.
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