全文获取类型
收费全文 | 2719篇 |
免费 | 240篇 |
出版年
2023年 | 14篇 |
2022年 | 53篇 |
2021年 | 95篇 |
2020年 | 51篇 |
2019年 | 70篇 |
2018年 | 83篇 |
2017年 | 51篇 |
2016年 | 111篇 |
2015年 | 161篇 |
2014年 | 179篇 |
2013年 | 199篇 |
2012年 | 270篇 |
2011年 | 243篇 |
2010年 | 136篇 |
2009年 | 116篇 |
2008年 | 136篇 |
2007年 | 141篇 |
2006年 | 99篇 |
2005年 | 113篇 |
2004年 | 107篇 |
2003年 | 70篇 |
2002年 | 59篇 |
2001年 | 25篇 |
2000年 | 21篇 |
1999年 | 17篇 |
1998年 | 16篇 |
1997年 | 10篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 12篇 |
1992年 | 17篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 13篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 14篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 11篇 |
1978年 | 16篇 |
1977年 | 12篇 |
1976年 | 7篇 |
1969年 | 7篇 |
1967年 | 10篇 |
1944年 | 6篇 |
1943年 | 6篇 |
排序方式: 共有2959条查询结果,搜索用时 312 毫秒
111.
112.
Iman Mehdizadeh Gohari Andrew M. Kropinski Scott J. Weese Valeria R. Parreira Ashley E. Whitehead Patrick Boerlin John F. Prescott 《PloS one》2016,11(2)
The recent discovery of a novel beta-pore-forming toxin, NetF, which is strongly associated with canine and foal necrotizing enteritis should improve our understanding of the role of type A Clostridium perfringens associated disease in these animals. The current study presents the complete genome sequence of two netF-positive strains, JFP55 and JFP838, which were recovered from cases of foal necrotizing enteritis and canine hemorrhagic gastroenteritis, respectively. Genome sequencing was done using Single Molecule, Real-Time (SMRT) technology-PacBio and Illumina Hiseq2000. The JFP55 and JFP838 genomes include a single 3.34 Mb and 3.53 Mb chromosome, respectively, and both genomes include five circular plasmids. Plasmid annotation revealed that three plasmids were shared by the two newly sequenced genomes, including a NetF/NetE toxins-encoding tcp-conjugative plasmid, a CPE/CPB2 toxins-encoding tcp-conjugative plasmid and a putative bacteriocin-encoding plasmid. The putative beta-pore-forming toxin genes, netF, netE and netG, were located in unique pathogenicity loci on tcp-conjugative plasmids. The C. perfringens JFP55 chromosome carries 2,825 protein-coding genes whereas the chromosome of JFP838 contains 3,014 protein-encoding genes. Comparison of these two chromosomes with three available reference C. perfringens chromosome sequences identified 48 (~247 kb) and 81 (~430 kb) regions unique to JFP55 and JFP838, respectively. Some of these divergent genomic regions in both chromosomes are phage- and plasmid-related segments. Sixteen of these unique chromosomal regions (~69 kb) were shared between the two isolates. Five of these shared regions formed a mosaic of plasmid-integrated segments, suggesting that these elements were acquired early in a clonal lineage of netF-positive C. perfringens strains. These results provide significant insight into the basis of canine and foal necrotizing enteritis and are the first to demonstrate that netF resides on a large and unique plasmid-encoded locus. 相似文献
113.
114.
Priscilla F. McAuliffe Kurt W. Evans Argun Akcakanat Ken Chen Xiaofeng Zheng Hao Zhao Agda Karina Eterovic Takafumi Sangai Ashley M. Holder Chandeshwar Sharma Huiqin Chen Kim-Anh Do Emily Tarco Mihai Gagea Katherine A. Naff Aysegul Sahin Asha S. Multani Dalliah M. Black Elizabeth A. Mittendorf Isabelle Bedrosian Gordon B. Mills Ana Maria Gonzalez-Angulo Funda Meric-Bernstam 《PloS one》2016,11(3)
115.
116.
117.
Ashley N. Edes Barbara A. Wolfe Douglas E. Crews 《International journal of primatology》2016,37(2):241-259
Stress contributes to the development of chronic degenerative diseases in primates. Allostatic load is an estimate of stress-induced physiological dysregulation based on an index of multiple biomarkers. It has been applied to humans to measure effects of stress and predict health outcomes. Assessing allostatic load in nonhuman primates may aid in understanding factors promoting compromised health and longevity in captive populations, as well as risk assessment among wild populations following human activities. We applied an allostatic load index to gorillas housed at the Columbus Zoo and Aquarium (N = 27, 1956–2014) using data from medical records and biomarkers from banked serum. We estimated allostatic load using seven biomarkers (albumin, cortisol, corticotropin-releasing hormone, dehydroepiandrosterone sulfate, glucose, interleukin-6, and tumor necrosis factor alpha) and then examined this index for associations with age, sex, number of stressful events, parturition, physiological health measures, and age at death. Stressful events were defined as agonistic interactions with wounding, translocations, and anesthetizations. Allostatic load positively associated with age and total number of lifetime stressful events. Allostatic load was significantly higher in females than in males. Allostatic load was not associated with number of pregnancies and was not different between nulliparous and parous females. Allostatic load associated positively with serum creatinine and triglyceride levels, showed a nonsignificant negative association with cholesterol, and did not associate significantly with age at death. These results demonstrate the potential utility of allostatic load for exploring long-term stress and health risks, as well as for evaluating environmental stressors for gorillas and other nonhuman primates in captivity and in the wild. 相似文献
118.
Towards an international expert consensus for defining treatment response,remission, recovery and relapse in obsessive‐compulsive disorder
下载免费PDF全文
![点击此处可从《World psychiatry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
119.
Vicuna Requesens Deborah Gonzalez Romero Maria Elena Devaiah Shivakumar P. Chang Yeun-Kyung Flory Ashley Streatfield Stephen Ring Rebecca Phillips Cassie Hood Nathan C. Marbaniang Cyrus Dean Howard John A. Hood Elizabeth E. 《Transgenic research》2019,28(5-6):537-547
Transgenic Research - Expression of recombinant proteins in plants is a technology for producing vaccines, pharmaceuticals and industrial enzymes. For the past several years, we have produced... 相似文献
120.
Yumin Dai Ashley N. Peralta Jessica E. Wynn Chringma Sherpa Hao Li Astha Verma Stuart F.J. Le Grice Webster L. Santos 《Bioorganic & medicinal chemistry》2019,27(8):1759-1765
Interaction of HIV-1 rev response element (RRE) RNA with its cognate protein, Rev, is critical for HIV-1 replication. Understanding the mode of interaction between RRE RNA and ligands at the binding site can facilitate RNA molecular recognition as well as provide a strategy for developing anti-HIV therapeutics. Our approach utilizes branched peptides as a scaffold for multivalent binding to RRE IIB (high affinity rev binding site) with incorporation of unnatural amino acids to increase affinity via non-canonical interactions with the RNA. Previous high throughput screening of a 46,656-member library revealed several hits that bound RRE IIB RNA in the sub-micromolar range. In particular, the lead compound, 4B3, displayed a Kd value of 410?nM and demonstrated selectivity towards RRE. A ribonuclease protection assay revealed that 4B3 binds to the stem-loop structure of RRE IIB RNA, which was confirmed by SHAPE analysis with 234 nt long NL4-3 RRE RNA. Our studies further indicated interaction of 4B3 with both primary and secondary Rev binding sites. 相似文献