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1.
A series of measurements of blood pressure in normotensive and hypertensive subjects showed that measurements made with a sphygmomanometer with the arm dependent by the side were consistently higher than those made with the arm horizontal at heart level. The mean difference in a group of 90 hypertensive outpatients was 11/12 mm Hg. Failure to appreciate the importance of arm position may lead to erroneous measurements of blood pressure. This has important implications for clinical practice and research. 相似文献
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Methyl 5-acetamido-3,5-dideoxy-2-O-methyl-D-glycero-D-galacto-2-nonulopyrano sate was converted into the 9-O-trityl derivative and the remaining hydroxyl groups were protected as benzyl ethers. Removal of the trityl group, followed by treatment with diethylaminosulfur trifluoride gave the 9-deoxy-9-fluoro derivative, and deprotection N-acetyl-9-deoxy-9-fluoroneuraminic acid (8). In another procedure, coupling of 2-acetamido-2,6-dideoxy-6-fluoro-D-glucopyranose with potassium di(tert-butyl) oxaloacetate, followed by hydrolysis and decarboxylation gave 8. Some of the derivatives were active as inhibitors of growth of mouse mammary adenocarcinoma (TA3) and L1210 cells in culture. 相似文献
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Characterization of temperature-sensitive mutants of simian rotavirus SA11: protein synthesis and morphogenesis. 总被引:8,自引:7,他引:1
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The synthesis of viral polypeptides, distribution of viral antigens, and morphogenesis of viral structures have been examined in cells infected with temperature-sensitive (ts) mutants of SA11 representing 10 recombination groups. At the permissive temperature (31 degrees C) the synthesis of viral polypeptides and the distribution of viral antigens did not differ significantly from those of the wild type. At the nonpermissive temperature (39 degrees C) some mutants (tsB, -C, -E, -F, and -G) synthesized significantly smaller amounts of viral polypeptides and had a very diffuse distribution of viral antigen. Several of the mutants synthesized one or more electrophoretically aberrant polypeptide species at both 31 and 39 degrees C. All of the mutants, except tsF, assembled morphogenetic intermediates at 39 degrees C. Aberrant intermediates were assembled in all mutants at 31 and 39 degrees C. No specific morphogenic defect could be associated with any of the ts mutants. 相似文献
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The phylogeny of Greya Busck (Lepidoptera: Prodoxidae) was inferred from
nucleotide sequence variation across a 765-bp region in the cytochrome
oxidase I and II genes of the mitochondrial genome. Most parsimonious
relationships of 25 haplotypes from 16 Greya species and two outgroup
genera (Tetragma and Prodoxus) showed substantial congruence with the
species relationships indicated by morphological variation. Differences
between mitochondrial and morphological trees were found primarily in the
positions of two species, G. variabilis and G. pectinifera, and in the
branching order of the three major species groups in the genus. Conflicts
between the data sets were examined by comparing levels of homoplasy in
characters supporting alternative hypotheses. The phylogeny of Greya
species suggests that host-plant association at the family level and larval
feeding mode are conservative characters. Transition/transversion ratios
estimated by reconstruction of nucleotide substitutions on the phylogeny
had a range of 2.0-9.3, when different subsets of the phylogeny were used.
The decline of this ratio with the increase in maximum sequence divergence
among taxa indicates that transitions are masked by transversions along
deeper internodes or long branches of the phylogeny. Among transitions,
substitutions of A-->G and T-->C outnumbered their reciprocal
substitutions by 2-6 times, presumably because of the approximately 4:1
(77%) A+T-bias in nucleotide base composition. Of all transversions,
73%-80% were A<-->T substitutions, 85% of which occurred at third
positions of codons; these estimates did not decrease with an increase in
maximum sequence divergence of taxa included in the analysis. The high
frequency of A<-->T substitutions is either a reflection or an
explanation of the 92% A+T bias at third codon positions.
相似文献
10.
Anita Shepherd Danny Awty-Carroll Jason Kam Chris Ashman Elena Magenau Enrico Martani Mislav Kontek Andrea Ferrarini Stefano Amaducci Chris Davey Vanja Jurišić Gert-Jan Petrie Mohamad Al Hassan Isabelle Lamy Iris Lewandowski Emmanuel de Maupeou Jon McCalmont Luisa Trindade Kasper van der Cruijsen Philip van der Pluijm Rebecca Rowe Andrew Lovett Iain Donnison Andreas Kiesel John Clifton-Brown Astley Hastings 《Global Change Biology Bioenergy》2023,15(4):444-461
New biomass crop hybrids for bioeconomic expansion require yield projections to determine their potential for strategic land use planning in the face of global challenges. Our biomass growth simulation incorporates radiation interception and conversion efficiency. Models often use leaf area to predict interception which is demanding to determine accurately, so instead we use low-cost rapid light interception measurements using a simple laboratory-made line ceptometer and relate the dynamics of canopy closure to thermal time, and to measurements of biomass. We apply the model to project the European biomass potentials of new market-ready hybrids for 2020–2030. Field measurements are easier to collect, the calibration is seasonally dynamic and reduces influence of weather variation between field sites. The model obtained is conservative, being calibrated by crops of varying establishment and varying maturity on less productive (marginal) land. This results in conservative projections of miscanthus hybrids for 2020–2030 based on 10% land use conversion of the least (productive) grassland and arable for farm diversification, which show a European potential of 80.7–89.7 Mt year−1 biomass, with potential for 1.2–1.3 EJ year−1 energy and 36.3–40.3 Mt year−1 carbon capture, with seeded Miscanthus sacchariflorus × sinensis displaying highest yield potential. Simulated biomass projections must be viewed in light of the field measurements on less productive land with high soil water deficits. We are attempting to model the results from an ambitious and novel project combining new hybrids across Europe with agronomy which has not been perfected on less productive sites. Nevertheless, at the time of energy sourcing issues, seed-propagated miscanthus hybrids for the upscaled provision of bioenergy offer an alternative source of renewable energy. If European countries provide incentives for growers to invest, seeded hybrids can improve product availability and biomass yields over the current commercial miscanthus variety. 相似文献