全文获取类型
收费全文 | 373篇 |
免费 | 34篇 |
出版年
2022年 | 3篇 |
2021年 | 8篇 |
2019年 | 10篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 6篇 |
2015年 | 12篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 33篇 |
2011年 | 25篇 |
2010年 | 17篇 |
2009年 | 15篇 |
2008年 | 19篇 |
2007年 | 22篇 |
2006年 | 12篇 |
2005年 | 13篇 |
2004年 | 13篇 |
2003年 | 15篇 |
2002年 | 16篇 |
2001年 | 7篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1997年 | 6篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1993年 | 2篇 |
1992年 | 5篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1979年 | 2篇 |
1977年 | 4篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1973年 | 2篇 |
1972年 | 4篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1968年 | 2篇 |
1959年 | 2篇 |
1957年 | 3篇 |
1941年 | 4篇 |
排序方式: 共有407条查询结果,搜索用时 171 毫秒
131.
In this paper, a two-phenotype, single-locus, n -allele matrix game diploid model incorporating interactions between full sibs influencing personal fitness is investigated. Necessary and sufficient conditions for an ESS are given. We show that if a strategy is an ESS for this model with the payoff matrix A, then it must be an ESS for the standard game formulation with payoff matrix A+(r/2) A(T) where r is the probability to interact with a sib, but it is also possible that no ESS exists. Moreover, under the assumption of weak selection, the partial change in phenotype frequencies brings the population closer to an ESS when it exists. 相似文献
132.
133.
134.
135.
136.
Lei Qian Zujin Huang Hui Liu Xiaowei Liu Yixuan Jin Sabin Saurav Pokharel Fajun Chen 《Journal of Applied Entomology》2021,145(8):777-788
Globally rising atmosphere CO2 has been predicted to affect the emission of plant volatile organic compounds (VOCs) and the interaction with insect herbivores. CO2-mediated plant VOCs change might contribute to develop effective management strategies for insect pests by using VOCs related biological control methods. In this study, we analysed the effect of elevated CO2 on the host-selection behaviour of western flower thrips (Frankliniella occidentalis) and studied how they were affected by the release of VOCs from kidney bean plants (Phaseolus vulgaris). A four-chamber olfactometer was used to quantify the host-selection of F. occidentalis for P. vulgaris. Elevated CO2 increased F. occidentalis' selection for P. vulgaris wounded by mechanical damage (MD) and thrips infestation (TI) that might via regulating the gene expression of CSP1, CSP1-q, OBP1 and OBP1-q in F. occidentalis. Besides, we cultivated kidney beans at ambient CO2 (400 ppm) and elevated CO2 (800 ppm), and quantified the emission of plant VOCs by using GC-MS. Thirty VOCs belonging to ten chemical groups were identified from P. vulgaris, including aromatic hydrocarbons, ethers, alkanes, cycloalkanes, alcohols, alkenes, aromatic derivatives, phenols, ketones and esters. Furthermore, six VOCs from P. vulgaris were significantly affected by CO2 level, wounding way and the interaction between them, including ethyl benzene, 1,3-dimethyl benzene, 1,3-dimethyl-4-ethyl benzene, (E,E,E,E)-squalene, 2,6-ditert-butyl-4-methyl phenol and dioctyl phthalate. Our study indicates that elevated CO2 might increase the host-selection of F. occidentalis for wounded P. vulgaris due to the changed plant VOCs. 相似文献
137.
Sabin MA Yau SW Russo VC Clarke IJ Dunshea FR Chau J Cox M Werther GA 《Obesity (Silver Spring, Md.)》2011,19(12):2374-2381
The aim of this study was to investigate effects of dietary supplementation with fat or sugar on body composition (BC) and insulin sensitivity (IS) in maturing pigs. Fifty newborn pigs randomized to a control diet or 18% saturated fat (SF), 18% monounsaturated fat (MUF), 18% mixed fat (MF), or 50% sucrose (SUC), from 1 to 16 weeks of age. Outcomes included weight gain, BC (dual energy X-ray absorptiometry, DXA), IS (fasting insulin and hyperinsulinaemic-euglycaemic clamps), fasting Non-Esterified Fatty Acid (NEFA) concentrations, and mRNA expression of genes involved in lipogenesis and IS in skeletal muscle (SM), subcutaneous (SAT), and visceral adipose tissue (VAT). In vitro studies examined direct effects of fatty acids on insulin-like growth factor-binding protein 2 (IGFBP2) mRNA in C2C12 myotubes. While SUC-fed pigs gained most weight (due to larger quantities consumed; P < 0.01), those fed fat-enriched diets exhibited more weight gain per unit energy intake (P < 0.001). Total (P = 0.03) and visceral (P = 0.04) adiposity were greatest in MUF-fed pigs. Whole-body IS was decreased in those fed fat (P = 0.04), with fasting insulin increased in MUF-fed pigs (P = 0.03). SM IGFBP2 mRNA was increased in MUF-fed pigs (P = 0.009) and, in all animals, SM IGFBP2 mRNA correlated with total (P = 0.007) and visceral (P = 0.001) fat, fasting insulin (r = 0.321; P = 0.03) and change in NEFA concentrations (r = 0.285; P = 0.047). Furthermore, exposure of in vitro cultured myotubes to MUF, but not SF, reduced IGFBP2 mRNA suggesting a converse direct effect. In conclusion, diets high in fat, but not sugar, promote visceral adiposity and insulin resistance in maturing pigs, with evidence that fatty acids have direct and indirect effects on IGFBP2 mRNA expression in muscle. 相似文献
138.
139.
RNA polymerase II translocates across much of the genome and since it can be blocked by many kinds of DNA lesions, detects DNA damage proficiently; it thereby contributes to DNA repair and to normal levels of DNA damage resistance. However, the components and mechanisms that respond to polymerase blockage are largely unknown, except in the case of UV-induced damage that is corrected by nucleotide excision repair. Because elongating RNAPII carries with it numerous proteins that bind to its hyperphosphorylated CTD, we tested for effects of interfering with this binding. We find that expressing a decoy CTD-carrying protein in the nucleus, but not in the cytoplasm, leads to reduced DNA damage resistance. Likewise, inducing aberrant phosphorylation of the CTD, by deleting CTK1, reduces damage resistance and also alters rates of homologous recombination-mediated repair. In line with these results, extant data sets reveal a remarkable, highly significant overlap between phosphoCTD-associating protein genes and DNA damage-resistance genes. For one well-known phosphoCTD-associating protein, the histone methyltransferase Set2, we demonstrate a role in DNA damage resistance, and we show that this role requires the phosphoCTD binding ability of Set2; surprisingly, Set2’s role in damage resistance does not depend on its catalytic activity. To explain all of these observations, we posit the existence of a CTD-Associated DNA damage Response (CAR) system, organized around the phosphoCTD of elongating RNAPII and comprising a subset of phosphoCTD-associating proteins. 相似文献
140.