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1.
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2.
Alexander Scheeline John A. Norris J.C. Travis J.R. Devoe John P. Walters 《Spectrochimica Acta Part B: Atomic Spectroscopy》1981,36(4):373-383
Light scattering was used to demonstrate the presence of small (?1 μm) particles in the immediate surroundings of a stable spark discharge. Several parameters, including electrode composition and surface condition, which are of importance in emission spectrochemical analysis, were found to be of importance in affecting the scattering signal. Electron micrographs of the heaviest particles revealed two distinct types of particles. Analytical implications are discussed. 相似文献
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KM Varier AM Vinodkumar NVSV Prasad PV Madhusudhana Rao DL Sastry Lagy T Baby MC Radhakrishna NG Puttaswamy JJ Das P Sugathan N Madhavan AK Sinha DO Kataria 《Pramana》1999,53(3):529-533
Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies.
Coupled channel calculations incorporating couplings to 2+ and 3− states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements
had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer
were carried out for 46,48Ti+61Ni systems. The present paper gives the results of these studies. 相似文献
4.
WYETH Paul 《中国科学:化学》2010,(3)
Silks represent some of the most precious ancient and historic textile artefacts in collections worldwide.Their optimum preservation demands an appreciation of their characteristics.One important concern,especially with regard to ancient Chinese silks,is whether the fabrics have been degummed.Silks with remnant sericin gum coating the fibroin fibres would require different conservation protocol.In previous research on aged silks,the presence of sericin has been inferred from amino acid analysis of hydrolysa... 相似文献
5.
Radioisotope dilution principles are applied to controlled-potential electrolysis and solvent extraction with dithizone for the determination of trace amounts of cadmium. A method was developed to verify whether or not the substoichiometric principle was obeyed. If the substoichiometric principle was not obeyed, analysis was still possible by means of calibration curves. In order to obtain independent verification of the series controlled-potential method and to establish a means of comparison with the radioisotope dilution technique a current integration procedure was also employed. A microtechnique was used to extend the sensitivity of the solvent extraction system for cadmium. Standard zinc spelter and high-purity zinc were analyzed for cadmium after separation by a method of standard addition. 相似文献
6.
[formula: see text] Iron salts efficiently catalyze the Doyle-Kirmse reaction of allyl sulfides with (trimethylsilyl)diazomethane and ethyl diazoacetate in dichloroethane at 83 degrees C. Competitive dimerization is less of a problem with (trimethylsilyl)diazomethane than with ethyl diazoacetate. Good results are obtained using only 1.5 equiv of (trimethylsilyl)diazomethane, even without slow addition. Phosphine ligands affect the kinetics, but not the diastereoselectivity. Dppe and BINAP lead to higher yields than dppp, but no enantioselection was detected with R-(+)-BINAP. 相似文献
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Studies of lipid rafts, ordered microdomains of sphingolipids and cholesterol within cell membranes, are essential in probing the relationships between membrane organization and cellular function. While in vitro studies of lipid phase separation are commonly performed using spherical vesicles as model membranes, the utility of these models is limited by a number of factors. Here we present a microfluidic device that supports simultaneous electrical measurements and confocal imaging of on-chip bilayer lipid membranes (BLMs), enabling real-time multi-domain imaging of membrane organization. The chips further support closed microfluidic access to both sides of the membrane, allowing the membrane boundary conditions to be rapidly changed and providing a mechanism for dynamically adjusting membrane curvature through application of a transmembrane pressure gradient. Here we demonstrate the platform through the study of dynamic generation and dissolution of ordered lipid domains as membrane components are transported to and from the supporting annulus containing solvated lipids and cholesterol. 相似文献
10.
M Auger DJ Auty PS Barbeau E Beauchamp V Belov C Benitez-Medina M Breidenbach T Brunner A Burenkov B Cleveland S Cook T Daniels M Danilov CG Davis S Delaquis R Devoe A Dobi MJ Dolinski A Dolgolenko M Dunford W Fairbank J Farine W Feldmeier P Fierlinger D Franco G Giroux R Gornea K Graham G Gratta C Hall K Hall C Hargrove S Herrin M Hughes A Johnson TN Johnson A Karelin LJ Kaufman A Kuchenkov KS Kumar DS Leonard F Leonard D Mackay R Maclellan M Marino B Mong M Montero Díez AR Müller R Neilson 《Physical review letters》2012,109(3):032505
We report on a search for neutrinoless double-beta decay of ^{136}Xe with EXO-200. No signal is observed for an exposure of 32.5?kg?yr, with a background of ~1.5×10^{-3} kg^{-1}?yr^{-1}?keV^{-1} in the ±1σ region of interest. This sets a lower limit on the half-life of the neutrinoless double-beta decay T_{1/2}^{0νββ}(^{136}Xe)>1.6×10^{25} yr (90% C.L.), corresponding to effective Majorana masses of less than 140-380?meV, depending on the matrix element calculation. 相似文献