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111.
Plant leaf is a natural composite biomaterial, and its strength is closely related to the microstructure. In this paper, themechanical characteristics of eight species of plant leaves were investigated and analyzed. The ultimate strength of leaves andthe hardness of leaf surfaces were measured by using universal testing machine and nanoindenter tester, respectively. The tensilestrength of the parallel microstructure was investigated based on its cross-sectional mechanical model. The results of tensiontests indicate that the ultimate strength of a leaf is related to the material composition and structure. The coriaceous leavesusually exhibit higher tensile strength. For example, the Phyllostachys pubescens leaf can achieve the maximum ultimatestrength of 5.9091 N·mm-2. It is concluded from the results of hardness tests that material components of leaf surface caninfluence the surface hardness evidently. The leaf surface composed of more lignin and cellulose materials shows a highersurface hardness than that composed of more carbohydrates materials. 相似文献
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113.
Xiaolin Huang Dongming Qu Yue Liang Qinghua Huang Mengze Li Changchun Hou 《Journal of cellular biochemistry》2019,120(6):9667-9676
The elevated S100A4 level has been found in some inflammatory diseases. However, the expression and role of S100A4 in asthma is unknown. The expression of S100A4 in induced sputum and plasma from healthy control and asthmatics were assessed by ELISA. Then an allergen-induced asthma mouse model treatment with anti-S100A4 antibody was used to explore the role of S100A4 in the pathogenesis of asthma. The S100A4 levels in sputum not in plasma in asthmatics were significantly increased than those of healthy controls and were negatively correlated with some lung function parameters and were positively correlated with sputum eosinophilia and lymphocyte. The expression of S100A4 in the lung as well as in BALF were also significantly higher in the asthma mouse model and treatment with anti-S100A4 antibody exhibited reductions in inflammatory cell accumulation, inflammatory mediators, and airway hyper-responsiveness. We further showed that LY294002, a specific inhibitor of PI3K, markedly decreased S100A4 expression in lung and S100A4 secretion in BALF in asthmatic mice. In conclusion, these data demonstrated that S100A4 may be involved in the pathogenesis of airway inflammation in asthma. 相似文献
114.
大豆(Glycing soja)苗期光合呼吸和蒸腾作用中的能量代谢 总被引:1,自引:0,他引:1
本文研究了大豆(Glying soja)苗期在光合、呼吸和蒸腾作用中的能量代谢,结果表明,大豆苗期的能量输入为990Kcal.m~(-2)·h~(-1),能量吸收为40.42Kcal.m~(-2)·h~(-1),能量固定为14.71Kcal.m~(-2)·h~(-1),能量损耗为28.61Kcal.m~(-2)·h~(-1),能量积累为11.71Kcal。m~(-2)·h~(-1)。 由此可见,绝大多数的能量损耗于大豆苗期的能量代谢过程,其中,蒸腾作用中的能量损耗为25.71Kcal.m~(-2)·h~(-1),光呼吸和暗呼吸作用中的能量损耗为3.00Kcal.m~(-2)·h~(-1)。因此,大豆苗期能量利用效率仅为1.18%。 相似文献
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116.
Immunopotentiation of NKT cells by low-protein diet and the suppressive effect on tumor metastasis 总被引:2,自引:0,他引:2
Li C Bai X Wang S Tomiyama-Miyaji C Nagura T Kawamura T Abo T 《Cellular immunology》2004,231(1-2):96-102
Mice were fed with a 5% low-protein diet for two weeks, at which point tumor inoculation was conducted. Following this inoculation, the 5% low-protein diet was continued. On the other hand, control mice were fed with a normal diet (25% protein) and such diet was continued after tumor inoculation. In comparison with control mice, mice fed with the 5% low-protein diet showed a prominent prolongation of survival rate when injected with both EL4 and 3LL tumors. Interestingly, CD1d(-/-) mice, which primarily lack natural killer T (NKT) cells, did not show the prolongation of survival rate even when they received a 5% low-protein diet. The most striking phenomenon seen in tumor-bearing mice fed with the 5% low-protein diet was the suppression of tumor metastasis to the liver and lung. Such suppression was not seen in CD1d(-/-) mice who were fed with a 5% low-protein diet. Phenotypic study revealed that the proportion of NKT cells after tumor inoculation decreased in the mice fed with a normal diet. However, such decrease did not occur in mice fed with the 5% low-protein diet. Reflecting the activation of NKT cells by feeding, tumor cytotoxicity and cytokine production were also augmented by the 5% low-protein diet. These results suggest that a low-protein diet has the potential to augment the innate immunity against tumors, especially mediated by the activation of NKT cells. 相似文献
117.
Yuet-Kin Leung Bin Ouyang Liang Niu Changchun Xie Jun Ying Mario Medvedovic 《Epigenetics》2018,13(3):290-300
Faroe islanders consume marine foods contaminated with methylmercury (MeHg), polychlorinated biphenyls (PCBs), and other toxicants associated with chronic disease risks. Differential DNA methylation at specific CpG sites in cord blood may serve as a surrogate biomarker of health impacts from chemical exposures. We aimed to identify key environmental chemicals in cord blood associated with DNA methylation changes in a population with elevated exposure to chemical mixtures. We studied 72 participants of a Faroese birth cohort recruited between 1986 and 1987 and followed until adulthood. The cord blood DNA methylome was profiled using Infinium HumanMethylation450 BeadChips. We determined the associations of CpG site changes with concentrations of MeHg, major PCBs, other organochlorine compounds [hexachlorobenzene (HCB), p,p’-dichlorodiphenyldichloroethylene (p,p’-DDE) and p,p’-dichlorodiphenyltrichloroethane], and perfluoroalkyl substances. In a combined sex analysis, among the 16 chemicals studied, PCB congener 105 (CB-105) exposure was associated with the majority of differentially methylated CpG sites (214 out of a total of 250). In female-only analysis, only 73 CB-105 associated CpG sites were detected, 44 of which were mapped to genes in the ELAV1-associated cancer network. In males-only, methylation changes were seen for perfluorooctane sulfonate, HCB, and p,p’-DDE in 10,598, 1,238, and 1,473 CpG sites, respectively, 15% of which were enriched in cytobands of the X-chromosome associated with neurological disorders. In this multiple-pollutant and genome-wide study, we identified key epigenetic toxicants. The significant enrichment of specific X-chromosome sites in males implies potential sex-specific epigenome responses to prenatal chemical exposures. 相似文献
118.
HAOSHUI 《Cell research》1992,2(2):153-163
In this study,freeze-fractured specimens of allium cepa root tip meristems were examined under the scanning electron microscope(SEM),This technique permitted the visualization of the outer membrane of the nuclear envelope with nuclear pore complexes and polyribosomes.Some of the cell nuclei prepared with this procedure had fissures of various widths on their nuclear envelopes through which the nuclear lamina-like filaments(LLF) undernearth the nucleoplasmic side of the envelopes were clearly visible.The diameters of these filaments veried between 25 and 125nm.Many of the LLFs showed granular thickenings at places,and were attached to the inner surface of nuclear envelope in some regions .Similar LLFs were also seen at the peripheries of the freeze-fractured faces of nuclei.Meanwhile,the spatial relation between the nuclear matrix filaments(NMF) and other nuclear structures(nucleoli,chromation and peripheral lamina-like filaments) was revealed in these fractured preparations.In addition,the methods and techniques in studying the nuclear lamina morphology and the roles played by NMFs in activities of various nuclear sturctures were discessed in brief. 相似文献
119.
120.
Lili Wang Changchun Yu Cong Chen Chunlan He Yingguo Zhu Wenchao Huang 《Plant cell reports》2014,33(12):2047-2062