A compilation of data on biomass and growth allowed an examination of the intraspecific plasticity in Tha/assia hemprichii which played key roles to develop site-specific growth strategies for this species in Xincun B...A compilation of data on biomass and growth allowed an examination of the intraspecific plasticity in Tha/assia hemprichii which played key roles to develop site-specific growth strategies for this species in Xincun Bay. The results showed the difference in rhizome elongation rates which explained most of the variation of biomass and growth within species. The seagrass T. hempdchii in Xincun Bay adjusted its vertical and horizontal rhizome elongation rates alternatively in response to light level and temperature changes, resulting in the variation of shoot densities and above biomass in return. The vertical and horizontal rhizomes elongated at rates of 2.38 and 24.4 cm yr1 in summer while 1.87 and 29.2 cm yr^-1 in winter respectively. The shoot density ranged from 822 to 941 shoots m^2 with a peak in summer and a trough in winter which was similar to that of biomass. The growth strategy enabled T. hempdchii to minimize the negative effects of desiccation in summer as well as light reduction in winter.展开更多
A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensi...A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensile strength on the micro parameters of the composite. These parameters contain fiber packing pattern, fiber volume fraction, and the modulus ratio of the fiber to the matrix. The investigation reveals that though the high fiber vo lume fraction, the high fiber′s modulus and the square fiber packing can supply strong reinforcement to the composite, the interface damage is susceptible in these cases. The tensile strength of the composite is dominated by the interface strength when the interface debonding occurs.展开更多
A 53-year-old male patient with a large hydatid cyst of the left hemidiaphragm and smaller secondary cysts located in the left thoracic cavity and upper left abdominal quadrant presented with two progressively enlargi...A 53-year-old male patient with a large hydatid cyst of the left hemidiaphragm and smaller secondary cysts located in the left thoracic cavity and upper left abdominal quadrant presented with two progressively enlarging lipoma-like masses in the left hypochondrium and under the left scapulae respectively. Total excision of all the cysts was performed through a bilateral subcostal incision, with the left hemidiaphragm near totally excised and replaced by a synthetic bilayer mesh.展开更多
Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoA...Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoAreductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues,respectively. Quantatitive RT-PCR analysis showed that both these genes were highly preferentially expressed duringthe cotton fiber elongation period with much lower levels recovered from roots, stems and leaves. GhKCR1 and 2showed 30%-32% identity to Saccharomyces cerevisiae Ybr159p at the deduced amino acid level. These cotton cDNAswere cloned and expressed in yeast haploid ybr159w? mutant that was deficient in 3-ketoacyl-CoA reductase activity.Wild-type growth rate was restored in ybr159w? cells that expressed either GhKCR1 or 2. Further analysis showed thatGhKCR1 and 2 were co-sedimented within the membranous pellet fraction after high-speed centrifugation, similar to theyeast endoplasmic reticulum marker ScKar2p. Both GhKCR(s) showed NADPH-dependent 3-ketoacyl-CoA reductaseactivity in an in vitro assay system using palmitoyl-CoA and malonyl-CoA as substrates. Our results suggest thatGhKCR1 and 2 are functional orthologues of ScYbr159p.展开更多
Rubber elasticity theory is of fundamental importance in polymer science. The traditional theory is athermal, describing rubber deformation behavior as entropy elasticity without an internal energy contribution. It ha...Rubber elasticity theory is of fundamental importance in polymer science. The traditional theory is athermal, describing rubber deformation behavior as entropy elasticity without an internal energy contribution. It has been found experimentally, however, that the internal energy contribution is not zero. In the present study we have used conformational elasticity theory to calculate the internal energy contribution of polydimethylsiloxane (PDMS) and results obtained are consistent with a number of experimental observations.展开更多
基金supported by UNEP and Global Environment Foundation (No. UNEP/GEF/SCS/Chi/MoU2c)the Key Innovation Project of Chinese Academy of Science ((No. KSCZ2-SW-132)the National Natural Science Foundation of China (No. 40576052 and No. U0633007)
文摘A compilation of data on biomass and growth allowed an examination of the intraspecific plasticity in Tha/assia hemprichii which played key roles to develop site-specific growth strategies for this species in Xincun Bay. The results showed the difference in rhizome elongation rates which explained most of the variation of biomass and growth within species. The seagrass T. hempdchii in Xincun Bay adjusted its vertical and horizontal rhizome elongation rates alternatively in response to light level and temperature changes, resulting in the variation of shoot densities and above biomass in return. The vertical and horizontal rhizomes elongated at rates of 2.38 and 24.4 cm yr1 in summer while 1.87 and 29.2 cm yr^-1 in winter respectively. The shoot density ranged from 822 to 941 shoots m^2 with a peak in summer and a trough in winter which was similar to that of biomass. The growth strategy enabled T. hempdchii to minimize the negative effects of desiccation in summer as well as light reduction in winter.
文摘A cohesive zone model is employed to simulate the fiber/matrix interface damage of composites with ductile matrix. The study is carried out to investigate the dependence of the interface damage and the composite tensile strength on the micro parameters of the composite. These parameters contain fiber packing pattern, fiber volume fraction, and the modulus ratio of the fiber to the matrix. The investigation reveals that though the high fiber vo lume fraction, the high fiber′s modulus and the square fiber packing can supply strong reinforcement to the composite, the interface damage is susceptible in these cases. The tensile strength of the composite is dominated by the interface strength when the interface debonding occurs.
文摘A 53-year-old male patient with a large hydatid cyst of the left hemidiaphragm and smaller secondary cysts located in the left thoracic cavity and upper left abdominal quadrant presented with two progressively enlarging lipoma-like masses in the left hypochondrium and under the left scapulae respectively. Total excision of all the cysts was performed through a bilateral subcostal incision, with the left hemidiaphragm near totally excised and replaced by a synthetic bilayer mesh.
基金supported by grants from China Na-tional Basic Research Program (NO. 2004CB117302)National Natural Science Foundation of China (No.30470171)the Sigrid Jusélius Foundation Finland and the Academy of Finland
文摘Genes encoding enzymes involved in biosynthesis of very long chain fatty acids were significantly up-regulatedduring early cotton fiber development. Two cDNAs, GhKCR1 and GhKCR2 encoding putative cotton 3-ketoacyl-CoAreductases that catalyze the second step in fatty acid elongation, were isolated from developing cotton fibers. GhKCR1and 2 contain open reading frames of 963 bp and 924 bp encoding proteins of 320 and 307 amino acid residues,respectively. Quantatitive RT-PCR analysis showed that both these genes were highly preferentially expressed duringthe cotton fiber elongation period with much lower levels recovered from roots, stems and leaves. GhKCR1 and 2showed 30%-32% identity to Saccharomyces cerevisiae Ybr159p at the deduced amino acid level. These cotton cDNAswere cloned and expressed in yeast haploid ybr159w? mutant that was deficient in 3-ketoacyl-CoA reductase activity.Wild-type growth rate was restored in ybr159w? cells that expressed either GhKCR1 or 2. Further analysis showed thatGhKCR1 and 2 were co-sedimented within the membranous pellet fraction after high-speed centrifugation, similar to theyeast endoplasmic reticulum marker ScKar2p. Both GhKCR(s) showed NADPH-dependent 3-ketoacyl-CoA reductaseactivity in an in vitro assay system using palmitoyl-CoA and malonyl-CoA as substrates. Our results suggest thatGhKCR1 and 2 are functional orthologues of ScYbr159p.
基金supported by the National Natural Science Foundation of China (29874035)
文摘Rubber elasticity theory is of fundamental importance in polymer science. The traditional theory is athermal, describing rubber deformation behavior as entropy elasticity without an internal energy contribution. It has been found experimentally, however, that the internal energy contribution is not zero. In the present study we have used conformational elasticity theory to calculate the internal energy contribution of polydimethylsiloxane (PDMS) and results obtained are consistent with a number of experimental observations.
