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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.
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
3.
A. C. Andrello C. R. Appoloni E. A. Cassol F. L. Melquiades 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(3):761-765
Summary Cesium-137 methodology has been successfully used to assess soil erosion. Seven erosion plots were sampled to determine the
137Cs profile and to assess the erosion rates. Cesium-137 profile for native pasture plot showed an exponential decline below
5 cm depth, with little 137Cs activity in the superficial layer (0-5 cm). Cesium-137 profile for wheat-soybean rotation plot in conventional tillage
showed a uniform distribution with depth. For this plot, the soil loss occurs more in middle than upper and lower level. Cesium-137
profile for wheat-soybean rotation and wheat-maize rotation plots in no-tillage showed a similar result to the native pasture,
with a minimum soil loss in the superficial layer. Cesium-137 profile for bare soil and cultivated pasture plots are similar,
with a soil erosion rate of 229 t ha-1 year -1 . In the plots with a conventional tillage a greater soil loss occur in middle than upper and lower level. In no-tillage
cultivation plots occurs soil loss in lower level, but no sign of soil loss neither gain in the upper level is observed. Cesium-137
methodology is a good tool to assess soil erosion and the 137Cs profile gives possibility to understand the soil erosion behavior in erosion plots. 相似文献
4.
Prof. Francesco Sannicolò Prof. Patrizia R. Mussini Prof. Tiziana Benincori Prof. Rocco Martinazzo Dr. Serena Arnaboldi Giulio Appoloni Dr. Monica Panigati Dr. Elsa Quartapelle Procopio Valentina Marino Dr. Roberto Cirilli Dr. Simone Casolo Prof. Wlodzimierz Kutner Dr. Krzysztof Noworyta Dr. Agnieszka Pietrzyk‐Le Zofia Iskierko Katarzyna Bartold 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(31):10839-10847
The racemate of an inherently chiral “spider‐like” octathiophene monomer T83 , in which chirality is generated by torsion in its backbone, was synthesized. The racemate was resolved into configurationally stable antipodes by HPLC on a chiral stationary phase. Electrooxidation of the enantiomers resulted in materials displaying high enantiorecognition ability towards the antipodes of some chiral probes. Moreover, the T83 racemate demonstrated great aptitude to stimulate formation of 3D rigid architectures if used as a cross‐linking monomer for molecular imprinting. This feature was exploited to devise a molecularly imprinted polymer‐based chemosensor selective for a thymine–adenine oligonucleotide. 相似文献
5.
Factorial design for Fe, Cu, Zn, Se and Pb preconcentration optimization with APDC and analysis with a portable X-ray fluorescence system 总被引:1,自引:0,他引:1
Preconcentration of heavy metals in water with ammonium pyrrolydine dithiocarbamate (APDC) is a common practice in analytical chemistry. A literature review on this topic showed that several authors use this precipitation agent, but in different preconcentration conditions, conducting to divergent results. The objective of this work is to use factorial design to optimize the factors involved in the preconcentration process of heavy metals using APDC. Five factors were studied: sample volume, solution pH, APDC concentration, APDC volume and stirring time. The assays were performed by energy dispersive X-ray fluorescence (EDXRF). The values for detection limits within 95% confidence level, in μg L−1, were: Fe (6.0 ± 0.1), Cu (4.0 ± 0.1), Zn (2.0 ± 0.1), Se (4.0 ± 0.1) and Pb (5.0 ± 0.1). The value for quantification limit for the five elements was 20 μg L−1, with 3% deviation. Multi-element standard solutions were prepared. Precipitation procedure was applied in the spiked solutions and the samples were filtered in cellulose ester membrane for quantification measurements. The optimum values obtained were 300 mL of sample solution, pH 4, 1 mL of 2% APDC and 10 min of stirring time. The concentration results obtained for the validation measurements were satisfactory for in situ survey employing a portable instrument. 相似文献
6.
M. S. Blonski C. R. Appoloni P. S. Parreira P. H. A. Arag?o V. F. Nascimento Filho 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(1):197-201
Summary Energy dispersion X-ray fluorescence technique (EDXRF) was employed to study the effects of the fumagina disease through the
elementary chemical composition of leaves. The experimental setup consisted of a Mo X-ray tube (Kμ=17.44 keV) with Zr filter and a Si(Li) detector. The measurements were performed with infected and healthy leaves of citric
plants. The elements Ti, Mn, Fe, Cu and Zn were quantified. For all the elements of interest the measured detection limit
was at the order of mg . g-1. 相似文献
7.
F. Lopes C. R. Appoloni V. F. Nascimento F. L. Melquiades L. C. Almeida 《Journal of Radioanalytical and Nuclear Chemistry》2006,270(1):43-46
Summary This paper presents the first measurement of the elemental composition of the suspended particulate matter in the atmosphere
of Londrina city (Paraná State, Brazil). The sampling was accomplished in the summer of 2003 and in the winter of 2002, with
a stacker filter holder, collecting simultaneously the fine particulates (PM2.5) and the coarse particulates (PM10). The concentration of K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br and Pb associated with particulate matter was determined
by energy dispersive X-ray fluorescence. The results of the grouping analysis suggested that the elements in the aerosol particles
came from two sources: soil re-suspension and industrial or anthropogenic activities. 相似文献
8.
Angular distributions and excitation functions of the elastic and inelastic scattering of 3He and α-particles by 122,124Te, 124Sn and 114Cd at incident energies around the Coulomb barrier were measured. The experimental results were analyzed in the framework of the optical model and DWBA taking into account the interference between nuclear and Coulomb excitation. Nuclear and charge deformation parameters were deduced. 相似文献
9.
M. C. da Rocha L. M. da Silva C. R. Appoloni O. Portezan Filho F. Lopes F. L. Melquíades E. A. dos Santos A. O. dos Santos A. C. Moreira W. E. Ptker E. de Almeida C. Q. Tannous R. Kuramoto F. H. de M. Cavalcante P. F. Barbieri A. F. Caleffi B. T. Carbonari G. Carbonari 《Radiation Physics and Chemistry》2001,61(3-6):567-569
Samples of concrete for popular habitation (0.1×0.03×0.1 m) and cellular concrete (0.1×0.05×0.1 m) were submitted to water vertical ascending infiltration. The moisture content spatial and temporal evolution of each sample it was monitored in three halfway positions in a same horizontal line, applying the gamma rays transmission method. The data were taken with a 137Cs (3.7×1010 Bq, 0662 MeV) source, Nal (Tl) of 2×2″ detector coupled to gamma ray spectrometry standard electronic with multichannel analyzer and a micrometric table. For the popular habitation concrete, there was a clear correlation between wetting profiles and concrete strength. The cellular concrete showed a wetting profile compatible to its greater porosity. 相似文献
10.