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排序方式: 共有94条查询结果,搜索用时 15 毫秒
31.
Mame T. Bakhoum Moussa Fall Assane G. Fall Glenn A. Bellis Yuval Gottlieb Karien Labuschagne Gert J. Venter Mariame Diop Iba Mall Momar T. Seck Xavier Allène Maryam Diarra La?titia Gardès Jérémy Bouyer Jean-Claude Delécolle Thomas Balenghien Claire Garros 《PloS one》2013,8(12)
The Schultzei group of Culicoides Latreille (Diptera: Ceratopogonidae) is distributed throughout Africa to northern Asia and Australasia and includes several potential vector species of livestock pathogens. The taxonomy of the species belonging to this species group is confounded by the wide geographical distribution and morphological variation exhibited by many species. In this work, morphological and molecular approaches were combined to assess the taxonomic validity of the species and morphological variants of the Schultzei group found in Senegal by comparing their genetic diversity with that of specimens from other geographical regions. The species list for Senegal was updated with four species: Culicoides kingi, C. oxystoma, C. enderleini and C. nevilli being recorded. This is the first record of C. oxystoma from Africa south of Sahara, and its genetic relationship with samples from Israel, Japan and Australia is presented. This work provides a basis for ecological studies of the seasonal and spatial dynamics of species of this species group that will contribute to better understanding of the epidemiology of the viruses they transmit. 相似文献
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Warrington CV Zhu S Parrott WA All JN Boerma HR 《Journal of economic entomology》2008,101(4):1471-1477
The development of superior soybean, Glycine max (L.) Merr., cultivars exhibiting resistance to insects has been hindered due to linkage drag, a common phenomenon when introgressing alleles from exotic germplasm. Simple-sequence repeat (SSR) markers were used previously to map soybean insect resistance (SIR) quantitative trait loci (QTLs) in a'Cobb' X PI 229358 population, and subsequently used to create near-isogenic lines (NILs) with SIR QTL i n a 'Benning' genetic background. SIR QTLs were mapped on linkage groups (LGs) M (SIRQTL-M), G (SIRQTL-G), and H (SIRQTL-H). The objectives of this study were to 1) evaluate linkage drag for seed yield by using Benning-derived NILs selected for SIRQTL-M, SIRQTL-H, and SIRQTL-G; 2) assess the amount of PI 229358 genome surrounding the SIR QTL in each Benning NIL; and 3) evaluate the individual effects these three QTLs on antibiosis and antixenosis to corn earworm, Helicoverpa zea (Boddie), and soybean looper, Pseudoplusia includens (Walker). Yield data collected in five environments indicated that a significant yield reduction is associated with SIRQTL-G compared with NILs without SIR QTL. Overall, there was no yield reduction associated with SIRQTL-M or SIRQTL-H. A significant antixenosis and antibiosis effect was detected for SIRQTL-M in insect feeding assays, with no effect detected in antixenosis or antibiosis assays for SIRQTL-G or SIRQTL-H without the presence of PI 229358 alleles at SIRQTL-M. These results support recent findings concerning these loci. 相似文献
34.
Trouvelot S Varnier AL Allègre M Mercier L Baillieul F Arnould C Gianinazzi-Pearson V Klarzynski O Joubert JM Pugin A Daire X 《Molecular plant-microbe interactions : MPMI》2008,21(2):232-243
Sulfated laminarin (PS3) has been shown previously to be an elicitor of plant defense reactions in tobacco and Arabidopsis and to induce protection against tobacco mosaic virus. Here, we have demonstrated the efficiency of PS3 in protecting a susceptible grapevine cultivar (Vitis vinifera cv. Marselan) against downy mildew (Plasmopara viticola) under glasshouse conditions. This induced resistance was associated with potentiated H2O2 production at the infection sites, upregulation of defense-related genes, callose and phenol depositions, and hypersensitive response-like cell death. Interestingly, similar responses were observed following P. viticola inoculation in a tolerant grapevine hybrid cultivar (Solaris). A pharmacological approach led us to conclude that both callose synthesis and jasmonic acid pathway contribute to PS3-induced resistance. 相似文献
35.
We hypothesized that biodegradation of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX)—a widely used explosive contaminating
soil and groundwater—by Rhodococcus strain YH1 is controlled by the presence of external nitrogen sources. This strain is capable of degrading RDX while using
it as sole nitrogen source under aerobic conditions. Both inorganic and organic nitrogen sources were found to have a profound
impact on RDX-biodegradation activity. This effect was tested in growing and resting cells of strain YH1. Nitrate and nitrite
delayed the onset of RDX degradation by strain YH1, while ammonium inhibited it almost completely. In addition, 2,4,6-trinitrotoluene
(TNT) inhibited RDX degradation and growth of strain YH1. On the other hand, tetrahydrophthalamide did not influence biodegradation
or growth. Growth on RDX induced the expression of a cytochrome P-450 enzyme that is suggested to be involved in the first
step in the aerobic pathway of RDX degradation, as identified by SDS-PAGE analysis. Ammonium and nitrite strongly repressed
cytochrome P-450 expression. Our findings suggest that effective RDX bioremediation by strain YH1 requires the design of a
treatment scheme that includes initial removal of ammonium, nitrite, nitrate and TNT before RDX degradation can take place. 相似文献
36.
Ghrelin expression in fetal, infant, and adult human lung. 总被引:8,自引:0,他引:8
Marco Volante Ezio Fulcheri Elena Allìa Milena Cerrato Angela Pucci Mauro Papotti 《The journal of histochemistry and cytochemistry》2002,50(8):1013-1021
Ghrelin is a recently identified hormone with potent growth hormone (GH)-releasing activity. It is produced by rat and human gastric endocrine cells and by the pituitary, hypothalamus, placenta, and by gastroenteropancreatic tumors. No evidence of ghrelin production by foregut-derived organs other than stomach has been provided to date. The aim of the present study was to investigate ghrelin expression by human fetal (20 cases), infant (13 cases), and adult (seven cases) lungs by immunohistochemistry, in situ hybridization, and RT-PCR. Expression of the GH secretagogue receptor, the endogenous receptor for ghrelin, was also investigated by RT-PCR. Ghrelin protein was found in the endocrine cells of the fetal lung in decreasing amounts from embryonic to late fetal periods. Its expression was maintained in newborns and children under 2 years but was virtually absent in older individuals. Scattered positive cells were also found in the trachea and the esophagus. Ghrelin mRNA was detected in adult lung by the more sensitive RT-PCR technique. GHS receptor mRNA was detected in nine cases of infant and adult lungs, possibly indicating the existence of local autocrine circuits. We conclude that the fetal lung is an additional source of circulating ghrelin, whose functions at the respiratory tract level remain to be clarified. 相似文献
37.
Ramat Hovav is a major chemical industrial park manufacturing pharmaceuticals, pesticides, and various aliphatic and aromatic halogens. All wastewater streams are collected in large evaporation ponds. Salinity in the evaporation ponds fluctuates between 3% (w/v) and saturation and pH values range between 2.0 and 10.0. We looked for microorganisms surviving in these extreme environmental conditions and found that 2 yeast strains dominate this biotope. 18S rDNA sequence analysis identified the isolates as Pichia guilliermondii and Rhodotorula mucilaginosa. Both isolates grew in NaCl concentrations ranging up to 3.5 M and 2.5 M, respectively, and at a pH range of 2-10. There was a distinct difference between the Rhodotorula and Pichia strains and S. cerevisiae RS16 that served as a control strain with respect to accumulation of osmoregulators and internal ion concentrations when exposed to osmotic stress. The Pichia and Rhodotorula strains maintained high glycerol concentration also in media low in NaCl. Utilization of various carbon sources was examined. Using a tetrazolium-based assay we show that the Rhodotorula and Pichia strains are capable of utilizing a wide range of different carbon sources including anthracene, phenanthrene, and other cyclic aromatic hydrocarbons. 相似文献
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40.
Ali Nejidat 《Physiologia plantarum》1995,94(3):411-414
Calcium ions play an important role in the regulation of stomatal movement and the mechanism underlying this action is yet to be determined. It is suggested that guard cell plasma membrane ATPase is a target for calcium action and that this effect is mediated by calmodulin. In this study, the effects of calcium and two calmodulin antagonists on ATPase activity in a crude homogenate of Commelina communis L. guard cell protoplasts were examined. The homogenate contained Mg2+ -dependent, K+ -simulated ATPase activity, which was inhibited by CaCl2 while stimulated by the calmodulin antagonists, compound 48/80 and chlorpromazine. The calmodulin antagonists partially reversed the inhibitory effect of calcium ions. The results support the possibility of calmodulin involvement in the regulation of guard cell ATPase activity by calcium ions. 相似文献