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排序方式: 共有620条查询结果,搜索用时 15 毫秒
1.
Ann McElroy 《Medical anthropology quarterly》1998,12(4):512-515
Evolution of Sickness and Healing. Horacio Fábrega Jr. Berkeley: University of California Press, 1997 (cloth), xv. 364pp. 相似文献
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Bioluminescence of Marine Dinoflagellates : I. An underwater photometer for day and night measurements 下载免费PDF全文
H. H. Seliger W. G. Fastie W. R. Taylor W. D. McElroy 《The Journal of general physiology》1962,45(5):1003-1017
Portable light-baffled underwater photometers have been designed for the measurement of dinoflagellate bioluminescence by day and night. Maximal light emission is obtained by mechanical stimulation in a defined volume. The pump which stimulates the dinoflagellates also constantly replenishes the sample volume so that continuous measurements are possible. Evidence for both diurnal variation and vertical migration is presented. Using luminous bacteria for calibration a single dinoflagellate has been found to emit of the order of 1010 light quanta per flash. The technique suggests that large scale mapping of bioluminescence is feasible. 相似文献
4.
David McElroy Douglas A. Chamberlain Eunpyo Moon Kate J. Wilson 《Molecular breeding : new strategies in plant improvement》1995,1(1):27-37
The use of reporter genes to characterise sequence elements that act to regulate gene expression in transgenic plants has been vital to the development of foreign gene expression strategies for use in cereal transformation. ThegusA locus ofEscherichia coli, which encodes the enzyme-glucuronidase (GUS), is by far the most popular reporter gene used in plant transformation. In this paper we extend the utility of the GUS reporter gene system in cereal transformation by describing and evaluating a number of novel constructs suitable for use in direct gene transfer experiments. These plasmids are all available from the Molecular Genetic Resource Service of the Center for the Application of Molecular Biology to International Agriculture. 相似文献
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Light-regulated and cell-specific expression of tomato rbcS-gusA and rice rbcS-gusA fusion genes in transgenic rice. 总被引:11,自引:4,他引:7 下载免费PDF全文
A previously isolated rice (Oryza sativa) rbcS gene was further characterized. This analysis revealed specific sequences in the 5' regulatory region of the rice rbcS gene that are conserved in rbcS genes of other monocotyledonous species. In transgenic rice plants, we examined the expression of the beta-glucuronidase (gusA) reporter gene directed by the 2.8-kb promoter region of the rice rbcS gene. To examine differences in the regulation of monocotyledonous and dicotyledonous rbcS promoters, the activity of a tomato rbcS promoter was also investigated in transgenic rice plants. Our results indicated that both rice and tomato rbcS promoters confer mesophyll-specific expression of the gusA reporter gene in transgenic rice plants and that this expression is induced by light. However, the expression level of the rice rbcS-gusA gene was higher than that of the tomato rbcS-gusA gene, suggesting the presence of quantitative differences in the activity of these particular monocotyledonous and dicotyledonous rbcS promoters in transgenic rice. Histochemical analysis of rbcS-gusA gene expression showed that the observed light induction was only found in mesophyll cells. Furthermore, it was demonstrated that the light regulation of rice rbcS-gusA gene expression was primarily at the level of mRNA accumulation. We show that the rice rbcS gene promoter should be useful for expression of agronomically important genes for genetic engineering of monocotyledonous species. 相似文献
6.
Jude M. Mathooko 《Hydrobiologia》1995,308(3):229-234
An investigation on the colonization of artificial substrate baskets by benthos was carried out in the Naro Moru River, a second-order high altitude river in Kenya, from November, 1986 to October, 1987. Simuliidae dominated the colonizing benthos. The mean (±95% CL) maximum colonization time was achieved after 9.63±1.57 days. The highest mean diversity (H) occurred after 6 days of exposure whilst the highest mean Hmaximum, evenness (J) and species richness (s) were achieved after 10, 8 and 10 days respectively.The benthos arrival rate (AR) declined exponentially with time. The changes in benthos departure rate (DR) with time was insignificant. Equilibrial state (AR:DR=1.0) was not achieved in the present study. 相似文献
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RAPD分析─鉴定柑桔体细胞杂种的快速方法 总被引:64,自引:3,他引:61
肖顺元 Frederick G.Gmitter Jude W.Grosser 黄舒XIAO Shun-Yuan Frederick G.Gmitter Jude W.Grosser HUANG Shu 《遗传》1995,17(4):40-42
本文利用改进的DNA提取方法,从Volkamer柠檬(Citrus volkameriana Ten. and Pasq.)和酸橙(C. aurantium L.)及其原生质体杂种植株的叶片中抽提总DNA,进行RAPD(Random Amplified Polymorphic DNA)分析。结果表明: 在随机选取的15种引物中,有10种可单独或与其它引物一道鉴定这一组合的体细胞杂种。与形态学性状观察、同工酶及ONA杂交分析等方法比较,RAPD分析是一种可在试管苗期即可直接、准确、快速鉴定柑桔体细胞杂种的方法。 相似文献
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Agrobacterium tumefaciens-mediated barley transformation 总被引:26,自引:2,他引:24
Sonia Tingay David McElroy Roger Kalla Sarah Fieg Mingbo Wang Sarah Thornton Richard Brettell 《The Plant journal : for cell and molecular biology》1997,11(6):1369-1376
Genetically transformed barley was produced by eco-cultivating immature embryo explants with Agrobacterium tumefaciens carrying a binary vector coding for chimaeric bacterial genes, bar and gus , and selecting for bialaphos-resistant cultures from which plants were regenerated. Integration of both genes was confirmed by gel blot hybridization analysis of DNA from the transformed plants and their progenies. From 1282 embryos, plants were recovered for 54 independently transformed lines, giving a transformation efficiency of 4.2%. Transgene numbers in the different lines ranged from single copy insertion to at least ten copies. Sixteen out of 18 plants grown to maturity were fully fertile. Both marker genes, bar and gus , were expressed and co-segregated in the T1 progeny plants. In the majority of cases, the genes showed Mendelian segregation predicted for transgene insertion at a single locus. In one family with multiple transgene insertions, molecular analysis of T1 and T2 plants suggested that the T-DNA had inserted at two unlinked loci. 相似文献
9.
There is growing evidence to support some form of light-activated phosphoinositide signal transduction pathway in the mammalian retina. Although this pathway plays no obvious role in mammalian phototransduction, mutations in this pathway cause retinal degenerations in Drosophila. These include the retinal degeneration A mutant, which is caused by an alteration in an eye-specific diacylglycerol kinase (DAGK) gene. In our efforts to consider genes mutated in Drosophila as candidates for mammalian eye disease, we have initially determined the map position of three DAGK genes in the mouse. 相似文献
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