全文获取类型
收费全文 | 2648篇 |
免费 | 204篇 |
国内免费 | 1篇 |
出版年
2022年 | 20篇 |
2021年 | 46篇 |
2020年 | 24篇 |
2019年 | 34篇 |
2018年 | 43篇 |
2017年 | 33篇 |
2016年 | 65篇 |
2015年 | 152篇 |
2014年 | 121篇 |
2013年 | 215篇 |
2012年 | 217篇 |
2011年 | 218篇 |
2010年 | 119篇 |
2009年 | 120篇 |
2008年 | 150篇 |
2007年 | 201篇 |
2006年 | 160篇 |
2005年 | 138篇 |
2004年 | 130篇 |
2003年 | 127篇 |
2002年 | 117篇 |
2001年 | 26篇 |
2000年 | 16篇 |
1999年 | 27篇 |
1998年 | 36篇 |
1997年 | 26篇 |
1996年 | 22篇 |
1995年 | 16篇 |
1994年 | 23篇 |
1993年 | 19篇 |
1992年 | 9篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1982年 | 6篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 5篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 4篇 |
1973年 | 7篇 |
1943年 | 3篇 |
1937年 | 3篇 |
排序方式: 共有2853条查询结果,搜索用时 15 毫秒
31.
32.
M Alvinerie A E Tufenkji G Houin P L Toutain P Galtier 《Comp. Biochem. Physiol. C, Comp. Pharmacol. Toxicol.》1989,94(1):81-86
1. The kinetics of intravenously administered prednisone (0.5 mg/kg) and methylprednisolone hemisuccinate (4 mg/kg) were compared in two groups of four young male sheep before and regularly after experimental infestation with 150 metacercariae of Fasciola hepatica and 5 or 7 weeks following a flukicidal treatment administered post-infection at week 25. 2. Parasitic pathology was ascertained by clinical observation and by the increase in plasma antibodies directed against liver flukes. 3. The disposition of prednisone was altered with a significant decrease of plasma clearance occurring from eleven weeks after infection onwards. This change was parallel to an increase in the mean residence time of prednisone and of its major metabolite (prednisolone). 4. The same parasitic burden provoked only a slight decrease in the elimination half-life of methylprednisolone alcohol when its hemisuccinate ester was administered. 相似文献
33.
34.
35.
Romain Benoist Claire Capdevielle‐Dulac Clina Chantre Rmi Jeannette Paul‐Andr Calatayud Jean‐Michel Drezen Stphane Dupas Arnaud Le Rouzic Bruno Le Ru Laurence Moreau Erwin Van Dijk Laure Kaiser Florence Mougel 《Molecular ecology》2020,29(18):3476-3493
Dissecting the genetic basis of intraspecific variations in life history traits is essential to understand their evolution, notably for potential biocontrol agents. Such variations are observed in the endoparasitoid Cotesia typhae (Hymenoptera: Braconidae), specialized on the pest Sesamia nonagrioides (Lepidoptera: Noctuidae). Previously, we identified two strains of C. typhae that differed significantly for life history traits on an allopatric host population. To investigate the genetic basis underlying these phenotypic differences, we used a quantitative trait locus (QTL) approach based on restriction site‐associated DNA markers. The characteristic of C. typhae reproduction allowed us generating sisters sharing almost the same genetic content, named clonal sibship. Crosses between individuals from the two strains were performed to generate F2 and F8 recombinant CSS. The genotypes of 181 clonal sibships were determined as well as the phenotypes of the corresponding 4,000 females. Informative markers were then used to build a high‐quality genetic map. These 465 markers spanned a total length of 1,300 cM and were organized in 10 linkage groups which corresponded to the number of C. typhae chromosomes. Three QTLs were detected for parasitism success and two for offspring number, while none were identified for sex ratio. The QTLs explained, respectively, 27.7% and 24.5% of the phenotypic variation observed. The gene content of the genomic intervals was investigated based on the genome of C. congregata and revealed 67 interesting candidates, as potentially involved in the studied traits, including components of the venom and of the symbiotic virus (bracovirus) shown to be necessary for parasitism success in related wasps. 相似文献
36.
Engelhardt Ilonka C. Niklaus Pascal A. Bizouard Florian Breuil Marie-Christine Rouard Nadine Deau Florence Philippot Laurent Barnard Romain L. 《Plant and Soil》2021,461(1-2):151-162
Plant and Soil - Contrasting nutrient-acquisition strategies would explain why species differ in their distribution in relation to soil phosphorus (P) availability, promoting diversity. However,... 相似文献
37.
38.
39.
Alexis Samba Mialoundama Nurul Jadid Julien Brunel Thomas Di Pascoli Dimitri Heintz Mathieu Erhardt Jér?me Mutterer Marc Bergdoll Daniel Ayoub Alain Van Dorsselaer Alain Rahier Paul Nkeng Philippe Geoffroy Michel Miesch Bilal Camara Florence Bouvier 《The Plant cell》2013,25(12):4879-4893
Sterols are vital for cellular functions and eukaryotic development because of their essential role as membrane constituents. Sterol biosynthetic intermediates (SBIs) represent a potential reservoir of signaling molecules in mammals and fungi, but little is known about their functions in plants. SBIs are derived from the sterol C4-demethylation enzyme complex that is tethered to the membrane by Ergosterol biosynthetic protein28 (ERG28). Here, using nonlethal loss-of-function strategies focused on Arabidopsis thaliana ERG28, we found that the previously undetected SBI 4-carboxy-4-methyl-24-methylenecycloartanol (CMMC) inhibits polar auxin transport (PAT), a key mechanism by which the phytohormone auxin regulates several aspects of plant growth, including development and responses to environmental factors. The induced accumulation of CMMC in Arabidopsis erg28 plants was associated with diagnostic hallmarks of altered PAT, including the differentiation of pin-like inflorescence, loss of apical dominance, leaf fusion, and reduced root growth. PAT inhibition by CMMC occurs in a brassinosteroid-independent manner. The data presented show that ERG28 is required for PAT in plants. Furthermore, it is accumulation of an atypical SBI that may act to negatively regulate PAT in plants. Hence, the sterol pathway offers further prospects for mining new target molecules that could regulate plant development. 相似文献
40.
Kristyn Echterling-Savage Florence D. DiGennaro Reed L. Keith Miller Sean Savage 《Journal of applied animal welfare science : JAAWS》2013,16(2):181-197
Problem behavior of companion animals poses a threat to caregivers, other targets of problem behavior (e.g., strangers, other nonhuman animals), and those animals engaging in problem behavior. This study examined the effects of an aggression reduction procedure (ARP) on dog problem behavior. After a baseline condition showing caregivers were unsuccessful in reducing dog aggression and the behaviors preceding aggression, caregivers were trained to implement a procedure to address dog problem behavior in relatively simple contexts. Generalization programming then was used to target caregiver plan implementation and dog problem behavior in more complex contexts. The ARP effectively reduced dog aggression for all dogs. A slight reduction and increased variability in dog precursor behavior was observed when the ARP was implemented. In addition, caregivers and experts rated the goals, procedures, and effects as acceptable. Implications of these findings are discussed. 相似文献