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141.
D L Garland 《Archives of biochemistry and biophysics》1979,198(1):335-337
A new method for assaying microtubule assembly is described. The method utilizes the colchicine binding property of tubulin. This technique was used to study the effect of cyclic AMP on tubulin assembly using 100,000g supernatant and cycle-purified tubulin prepared from porcine brain. Cyclic AMP, in the presence of NaF, inhibited tubulin assembly from 100,000g supernatant but had no effect on cycle-purified tubulin. 相似文献
142.
143.
144.
F. Rubio B.J. Miwa W.A. Garland 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1982,233(1):167-173
A method is described for measuring imidazobenzodiazepine-3-car☐yamide, a new anxiolytic agent, in human plasma. A tetradeuterated analogue of the analyte is used as the internal standard. The drug and its internal standard are (1) extracted from plasma at pH 9 with benzene containing 20% 1, 2-dichloroethane, (2) derivatized with pentafluoropropionic anhydride in the presence of triethylamine and (3) the nitrile derivative of the analyte and internal standard are analyzed by gas chromatography (GC)—negative chemical-ionization mass spectrometry (CIMS) using methane as both GC carrier gas and CI reagent gas. The mass spectrometer is set to monitor the intense (M-HCl)−- ions of imidazobenzodiazepine-3-nitrile and its tetradeuterated analogue atm/z 316 andm/z 320, respectively. Quantitation of an experimental plasma sample is based on the comparison of them/z 316 tom/z 320 ion ratio in each sample to that obtained from the analyses of control plasma spiked with various amounts of the drug and a fixed amount of internal standard. The limit of quantitation of the method is approximately 100 pg ml−1 of plasma and the precision (relative standard deviation) at a plasma concentration of 1 ng ml−1 is 4%. 相似文献
145.
Hugh G. Garland 《BMJ (Clinical research ed.)》1934,2(3842):346-348
146.
L. H. Garland 《The Western journal of medicine》1962,97(2):124-125
147.
ABSTRACTSleep deprivation impairs performance on cognitive tasks, but it is unclear which cognitive processes it degrades. We administered a semantic matching task with variable stimulus onset asynchrony (SOA) and both speeded and self-paced trial blocks. The task was administered at the baseline and 24 hours later after 30.8 hours of total sleep deprivation (TSD) or matching well-rested control. After sleep deprivation, the 20% slowest response times (RTs) were significantly increased. However, the semantic encoding time component of the RTs remained at baseline level. Thus, the performance impairment induced by sleep deprivation on this task occurred in cognitive processes downstream of semantic encoding. 相似文献
148.
Temperature is one of the main factors that determine sexual reproduction in terrestrial and emergent aquatic plant species. The effect of temperature on sexual reproduction and seed production of Glyceria maxima (Hartm.) Holmb. in the southern hemisphere is unknown. Glyceria maxima collections in February 2010 at three isolated infestations in KwaZulu-Natal failed to yield a single seed, only empty panicles. Laboratory experiments showed that vernalisation had no consistent effect on seed production. Field- and laboratory-grown plants produced seeds in the 2010/2011 season, because of having sufficient time at optimum temperatures required for seed production (1 491 and 1 585 hours, respectively), compared to a shorter period (1 352 hours) of suitable temperatures during the 2009/2010 growing season. An inadequate period of optimum temperatures (15–25°C) during seed production resulted in the lack of seeds in the field in the 2009/2010 growing season. This study showed that temperature and duration of exposure thereto during the seed-production period play vital roles in G. maxima sexual reproduction. 相似文献
149.
The partitioning of limited resources commonly explains how different species can coexist within the same ecological community. In this 2010 study, the diets of three coexisting freshwater fishes (Cape galaxias Galaxias zebratus, n = 27; Cape kurper Sandelia capensis, n = 60; Breede River redfin Pseudobarbus burchelli, n = 77) were characterised and compared in three headwater streams in South Africa's Cape Fold Ecoregion using gut contents and stable isotope analyses. These data were analysed to ascertain whether the three species exploit distinct trophic niches. Both approaches provided evidence that these species occupy different trophic niches, though with some overlap. However, dietary differences among sites were not consistent and were probably influenced by site-specific factors like resource availability. Pseudobarbus burchelli had a broader niche breadth at Tierkloof Stream than the other two species, but not at Waaihoek or Tierstel Streams. Our results also suggest that P. burchelli consumed a more omnivorous diet than do the other two species, whereas S. capensis occupied a higher trophic position than the other two species and consumed vertebrates. Our findings suggest that these species occupy non-equivalent feeding niches in Cape Fold Ecoregion headwater streams, and that diet partitioning might facilitate their coexistence in these systems. 相似文献
150.
L-Lactate dehydrogenase (L-LDH, E.C. 1.1.1.27) is encoded by two or three
loci in all vertebrates examined, with the exception of lampreys, which
have a single LDH locus. Biochemical characterizations of LDH proteins have
suggested that a gene duplication early in vertebrate evolution gave rise
to Ldh-A and Ldh-B and that an additional locus, Ldh-C arose in a number of
lineages more recently. Although some phylogenetic studies of LDH protein
sequences have supported this pattern of gene duplication, others have
contradicted it. In particular, a number of studies have suggested that
Ldh-C represents the earliest divergence among vertebrate LDHs and that it
may have diverged from the other loci well before the origin of
vertebrates. Such hypotheses make explicit statements about the
relationship of vertebrate and invertebrate LDHs, but to date, no closely
related invertebrate LDH sequences have been available for comparison. We
have attempted to provide further data on the timing of gene duplications
leading to multiple vertebrate LDHs by determining the cDNA sequence of the
LDH of the tunicate Styela plicata. Phylogenetic analyses of this and other
LDH sequences provide strong support for the duplications giving rise to
multiple vertebrate LDHs having occurred after vertebrates diverged from
tunicates. The timing of these LDH duplications is consistent with data
from a number of other gene families suggesting widespread gene duplication
near the origin of vertebrates. With respect to the relationships among
vertebrate LDHs, our data are not consistent with previous claims that
Ldh-C represented the earliest divergence. However, the precise
relationships among some of the main lineages of vertebrate LDHs were not
resolved in our analyses.
相似文献