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71.
本文根据大别山区霍山和金寨两县植物考察所积累的标本,提出一个包含近70种的常绿植物名录,其中有6种为华东或安徽新记录,9种为该区的新记录;这些植物中,约3/4—4/5均以该地为分布的北界。文中再次报道了以苦槠为优势的常绿阔叶林类型,证明该地区低海拔地带有耐寒性常绿阔叶林的分布。最后扼要讨论了华东区常绿植物和常绿阔叶林北部边缘的分布与当地气候条件的关系,除温度的主导作用外,还受水湿条件的制约,水湿条件起到补偿温度的作用。 相似文献
72.
汉滩病毒核壳蛋白(NP)在杆状病毒系统的表达及其免疫原性研究 总被引:11,自引:0,他引:11
应用杆状病毒表达载体成功地表达了汉滩病毒76-118株(HTNV)核壳蛋白,将HTNVS基因插入杆状病毒转染质粒pAcYMIB的多角体基因启动子下游附近,与经Bsu361酶切线性化的杆状病毒(AcVEPA)DNA共同转染S19细胞,经空斑筛选获得了高效表达NP的重组杆状病毒(AcVHanS)。经SDS-PAGE和Western blot证实,表达产物与HTNV毒粒NP分子量均为50KD左右,紫外扫 相似文献
73.
Cystine Deprivation Induces Oligodendroglial Death: Rescue by Free Radical Scavengers and by a Diffusible Glial Factor 总被引:4,自引:0,他引:4
Mihoko Yonezawa Stephen A. Back Xiaodong Gan Paul A. Rosenberg Joseph J. Volpe 《Journal of neurochemistry》1996,67(2):566-573
Abstract: In this study we examined the effect on oligodendroglial survival of exogenous cystine deprivation. Oligodendroglia isolated from mixed glial primary cultures derived from brains of 1-day-old rats, and then grown for 3 days, were markedly dependent on extracellular cystine for survival. The EC50 values for cystine for a 24-h exposure ranged from 2 to 65 µ M . After 6 h of cystine deprivation, the cellular glutathione level decreased to 21 ± 13% of the control. Free radical scavengers (α-tocopherol, ascorbate, idebenone, and N-tert -butyl-α-phenylnitrone) were protective against cystine deprivation but had no effect on the glutathione level. An iron chelator, desferrioxamine mesylate, also was protective. These findings suggest that intracellular hydroxyl radicals are important for this toxicity. In contrast to the observations in 3-day-old cultures, the dependence on exogenous cystine for cell viability was not observed consistently in oligodendroglia cultured for 6 days before the onset of cystine deprivation. Several observations suggested that this loss of cystine dependence was due to a diffusible factor. Sensitivity to the toxicity of cystine deprivation in day 6 cultures increased as the volume of medium was increased from 0.3 to 2 ml. Furthermore, preincubation of cystine-depleted medium with astrocyte cultures eliminated the toxicity of the cystine deprivation. HPLC assay of the conditioned cystine-depleted medium showed no significant change in cystine or cysteine concentration. We conclude that oligodendroglia are highly susceptible to cystine deprivation in day 3 cultures and that this susceptibility is due to the accumulation of intracellular free radicals in the setting of glutathione depletion. The resistance of day 6 oligodendroglial cultures is caused at least in part by a diffusible factor. 相似文献
74.
Longzhan Gan Shuai Zhang Yi Zhang Shuang He 《Preparative biochemistry & biotechnology》2013,43(7):582-588
AbstractWe have conducted a thorough study on extracellular biosynthesis of silver nanoparticles (AgNPs) by a halotolerant bacterium Bacillus endophyticus SCU-L, which was identified by 16S rRNA gene sequencing analysis. This strain was selected during an ongoing research programme aimed at finding a novel biological method for green nanosynthetic routes using the extremophiles in unexplored hypersaline habitats. The biosynthesized AgNPs were characterized and analyzed with UV–vis spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy and X-ray diffraction. Further, the AgNPs were found to be spherical in shape with an average particle size of about 5.1?nm, and it was stable in aqueous solution for three months period of storage at room temperature under dark condition. Also, the synthesized AgNPs significantly presented antimicrobial activity against Candida albicans, Escherichia coli, Salmonella typhi and Staphylococcus aureus. The above results suggested that the present work may provide a valuable reference and theoretical basis for further exploration on microbial biosynthesis of AgNPs by halotolerant bacteria. 相似文献
75.
76.
Gancho Slavov Paul Robson Elaine Jensen Edward Hodgson Kerrie Farrar Gordon Allison Sarah Hawkins Sian Thomas‐Jones Xue‐Feng Ma Lin Huang Timothy Swaller Richard Flavell John Clifton‐Brown Iain Donnison 《Global Change Biology Bioenergy》2013,5(5):562-571
Species and hybrids of Miscanthus are a promising energy crop, but their outcrossing mating systems and perennial life cycles are serious challenges for breeding programs. One approach to accelerating the domestication of Miscanthus is to harness the tremendous genetic variation that is present within this genus using phenotypic data from extensive field trials, high‐density genotyping and sequencing technologies, and rapidly developing statistical methods of relating phenotype to genotype. The success of this approach, however, hinges on detailed knowledge about the population genetic structure of the germplasm used in the breeding program. We therefore used data for 120 single‐nucleotide polymorphism and 52 simple sequence repeat markers to depict patterns of putatively neutral population structure among 244 Miscanthus genotypes grown in a field trial near Aberystwyth (UK) and delineate a population of 145 M . sinensis genotypes that will be used for association mapping and genomic selection. Comparative multivariate analyses of molecular marker and phenotypic data for 17 traits related to phenology, morphology/biomass, and cell wall composition revealed significant geographic patterns in this population. A longitudinal cline accounted for a substantial proportion of molecular marker variation (R2 = 0.60, P = 3.4 × 10?15). In contrast, genetic variation for phenotypic traits tended to follow latitudinal and altitudinal gradients, with several traits appearing to have been affected by divergent selection (i.e., QST >> FST). These contrasting geographic trends are unusual relative to other plants and provide opportunities for powerful studies of phenotype–genotype associations and the evolutionary history of M. sinensis. 相似文献
77.
Jinrui Gan Kun Qian Jingjing Wan Liang Qiao Weichao Guo Pengyuan Yang Hubert H. Girault Baohong Liu 《Proteomics》2013,13(21):3117-3123
Amino‐functionalized macroporous silica foam (NH2‐MOSF) has been developed as a host reactor to realize highly efficient proteolysis in acidic solutions where normal tryptic reactions cannot occur. The digestion protocol consists simply of adding the functionalized NH2‐MOSF into the protein and trypsin solutions without altering the bulk pH or preloading the enzymes on the materials. With this protocol, digestion of sample fractions from LC can be efficiently realized in the acidic solutions directly. Digestion of a protein fraction extracted from rat liver tissue after LC separation was performed to illustrate this principle, where 103 proteins were successfully identified at pH 3 after 1.5 h of tryptic digestion. 相似文献
78.
Sally Hamour Poh-Yi Gan Ruth Pepper Fernanda Florez Barros Hsu-Han Wang Kim O’Sullivan Yoichiro Iwakura Terence Cook Charles Pusey Stephen Holdsworth Alan Salama 《PloS one》2015,10(8)
IL-17 is a pro-inflammatory cytokine implicated in the pathogenesis of glomerulonephritis and IL-17 deficient mice are protected from nephrotoxic nephritis. However, a regulatory role for IL-17 has recently emerged. We describe a novel protective function for IL-17 in the kidney. Bone marrow chimeras were created using wild-type and IL-17 deficient mice and nephrotoxic nephritis was induced. IL-17 deficient hosts transplanted with wild-type bone marrow had worse disease by all indices compared to wild-type to wild-type bone marrow transplants (serum urea p<0.05; glomerular thrombosis p<0.05; tubular damage p<0.01), suggesting that in wild-type mice, IL-17 production by renal cells resistant to radiation is protective. IL-17 deficient mice transplanted with wild-type bone marrow also had a comparatively altered renal phenotype, with significant differences in renal cytokines (IL-10 p<0.01; IL-1β p<0.001; IL-23 p<0.01), and macrophage phenotype (expression of mannose receptor p<0.05; inducible nitric oxide synthase p<0.001). Finally we show that renal mast cells are resistant to radiation and produce IL-17, suggesting they are potential local mediators of disease protection. This is a novel role for intrinsic cells in the kidney that are radio-resistant and produce IL-17 to mediate protection in nephrotoxic nephritis. This has clinical significance as IL-17 blockade is being trialled as a therapeutic strategy in some autoimmune diseases. 相似文献
79.
Experiments have shown that the block of proventriculus develops in 1.1 to 1.5% of individuals of the flea Neopsylla abagaitui infected with plague microbe. These insects transmit the agent during bloodsucking to different plague carriers (Citellus dauricus, C. undulatus, Meriones unguiculatus, Microtus gregalis). The plague microbe is preserved in fleas for 65 days (the observation period). 相似文献
80.