全文获取类型
收费全文 | 543篇 |
免费 | 80篇 |
出版年
2021年 | 10篇 |
2018年 | 5篇 |
2017年 | 7篇 |
2016年 | 9篇 |
2015年 | 19篇 |
2014年 | 17篇 |
2013年 | 14篇 |
2012年 | 17篇 |
2011年 | 9篇 |
2010年 | 13篇 |
2009年 | 6篇 |
2008年 | 19篇 |
2007年 | 18篇 |
2006年 | 18篇 |
2005年 | 17篇 |
2004年 | 20篇 |
2003年 | 11篇 |
2002年 | 18篇 |
2001年 | 22篇 |
2000年 | 22篇 |
1999年 | 12篇 |
1998年 | 18篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 8篇 |
1988年 | 6篇 |
1987年 | 9篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 14篇 |
1982年 | 13篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 5篇 |
1976年 | 12篇 |
1975年 | 5篇 |
1974年 | 10篇 |
1973年 | 9篇 |
1971年 | 8篇 |
1969年 | 8篇 |
1963年 | 4篇 |
排序方式: 共有623条查询结果,搜索用时 15 毫秒
41.
The uptake, by oysters, of glucose is approximately 10–15 ng/hr/g wet weight, when glucose concentration in the saline was at 50 μg/ml. The removal of inorganic orthophosphate was approximately at a rate of 0.36 ng/hr/g wet weight. Radioactive studies indicate that these substrates are metabolized by oysters. The technique developed can be used to study oyster metabolism in the laboratory. 相似文献
42.
43.
44.
John L. Darcy Sean O. I. Swift Gerald M. Cobian Geoffrey L. Zahn Brian A. Perry Anthony S. Amend 《Molecular ecology》2020,29(16):3102-3115
A phylogenetically diverse array of fungi live within healthy leaf tissue of dicotyledonous plants. Many studies have examined these endophytes within a single plant species and/or at small spatial scales, but landscape‐scale variables that determine their community composition are not well understood, either across geographic space, across climatic conditions, or in the context of host plant phylogeny. Here, we evaluate the contributions of these variables to endophyte beta diversity using a survey of foliar endophytic fungi in native Hawaiian dicots sampled across the Hawaiian archipelago. We used Illumina technology to sequence fungal ITS1 amplicons to characterize foliar endophyte communities across five islands and 80 host plant genera. We found that communities of foliar endophytic fungi showed strong geographic structuring between distances of 7 and 36 km. Endophyte community structure was most strongly associated with host plant phylogeny and evapotranspiration, and was also significantly associated with NDVI, elevation and solar radiation. Additionally, our bipartite network analysis revealed that the five islands we sampled each harboured significantly specialized endophyte communities. These results demonstrate how the interaction of factors at large and small spatial and phylogenetic scales shapes fungal symbiont communities. 相似文献
45.
Androgens are thought to mediate sexual differentiation of spinal nucleus of the bulbocavernosus (SNB) motoneurons via actions on androgen receptors (ARs) within their target muscles bulbocavernosus and levator ani (LA). However, the cells within these muscles which mediate masculinization of the SNB remain undefined. Until recently, myocytes were thought to be the most likely candidate cell type. However, genetic tests of AR function in myocytes have failed to support a sufficient role for these cells in producing masculine SNB morphology, suggesting the involvement of other cell types. To identify other candidate cell types in the LA, we evaluated whether satellite cells or fibroblasts express AR. Fluorescent immunohistochemistry and confocal microscopy were used to evaluate whether satellite cells and fibroblasts express AR in neonatal male and female rats in the LA and an adjacent sexually monomorphic control muscle (CM). We found that a small proportion of satellite cells in the LA express AR and that this proportion is significantly greater in the LA compared to the CM. No sex differences were found between the proportions of satellite cells expressing AR in either muscle. Less colocalization of satellite cells and AR was seen in postnatal day 3 muscle than in postnatal day 1 muscle. In contrast, only negligible amounts of fibroblasts labeled with S100A4 express AR in either the LA or the CM. Together, findings support satellite cells, but not fibroblasts, as a candidate cell type involved in the sexual differentiation of the SNB neuromuscular system. © 2012 Wiley Periodicals, Inc. Develop Neurobiol 73: 448–454, 2013. 相似文献
46.
Jerome Irianto Joe Swift Rui?P. Martins Graham?D. McPhail Martin?M. Knight Dennis?E. Discher David?A. Lee 《Biophysical journal》2013,104(4):759-769
Changes in extracellular osmolality have been shown to alter gene expression patterns and metabolic activity of various cell types, including chondrocytes. However, mechanisms by which physiological or pathological changes in osmolality impact chondrocyte function remain unclear. Here we use quantitative image analysis, electron microscopy, and a DNase I assay to show that hyperosmotic conditions (>400 mOsm/kg) induce chromatin condensation, while hypoosmotic conditions (100 mOsm/kg) cause decondensation. Large density changes (p < 0.001) occur over a very narrow range of physiological osmolalities, which suggests that chondrocytes likely experience chromatin condensation and decondensation during a daily loading cycle. The effect of changes in osmolality on nuclear morphology (p < 0.01) and chromatin condensation (p < 0.001) also differed between chondrocytes in monolayer culture and three-dimensional agarose, suggesting a role for cell adhesion. The relationship between condensation and osmolality was accurately modeled by a polymer gel model which, along with the rapid nature of the chromatin condensation (<20 s), reveals the basic physicochemical nature of the process. Alterations in chromatin structure are expected to influence gene expression and thereby regulate chondrocyte activity in response to osmotic changes. 相似文献
47.
Varun C. Anipindi Puja Bagri Kristy Roth Sara E. Dizzell Philip V. Nguyen Christopher R. Shaler Derek K. Chu Rodrigo Jiménez-Saiz Hong Liang Stephanie L. Swift Aisha Nazli Jessica K. Kafka Jonathan Bramson Zhou Xing Manel Jordana Yonghong Wan Denis P. Snider Martin R. Stampfli Charu Kaushic 《PLoS pathogens》2016,12(6)
48.
Swift Candice L. Brown Jennifer L. Seppälä Susanna O’Malley Michelle A. 《Journal of industrial microbiology & biotechnology》2019,46(9-10):1427-1433
Journal of Industrial Microbiology & Biotechnology - Anaerobic gut fungi are biomass degraders that form syntrophic associations with other microbes in their native rumen environment. Here,... 相似文献
49.
Stephen B. Pyecroft Anne-Maree Pearse Richmond Loh Kate Swift Kathy Belov Nolan Fox Erin Noonan Dane Hayes Alex Hyatt Lingfa Wang David Boyle Jeff Church Debra Middleton Robert Moore 《EcoHealth》2007,4(3):346-351
In the mid 1990s an emerging disease characterised by the development of proliferative lesions around the face of Tasmanian
devils (Sarcophilus harrisii) was observed. A multi-disciplinary approach was adopted to define the condition. Histopathological and transmission electron
microscopic examination combined with immunohistochemistry help define Devil Facial Tumour Disease (DFTD) as a neoplastic
condition of cells of neuroendocrine origin. Cytogenetic analysis of neoplastic tissue revealed it to be markedly different
from normal devil tissue and having a consistent karyotype across all tumours examined. Combined with evidence for Major histocompatability
(MHC) gene analysis there is significant evidence to confirm the tumour is a transmissible neoplasm. 相似文献
50.
Hannah T Baddock Sanja Brolih Yuliana Yosaatmadja Malitha Ratnaweera Marcin Bielinski Lonnie
P Swift Abimael Cruz-Migoni Haitian Fan Jeremy R Keown Alexander P Walker Garrett
M Morris Jonathan
M Grimes Ervin Fodor Christopher
J Schofield Opher Gileadi Peter
J McHugh 《Nucleic acids research》2022,50(3):1484
The SARS-CoV-2 coronavirus is the causal agent of the current global pandemic. SARS-CoV-2 belongs to an order, Nidovirales, with very large RNA genomes. It is proposed that the fidelity of coronavirus (CoV) genome replication is aided by an RNA nuclease complex, comprising the non-structural proteins 14 and 10 (nsp14–nsp10), an attractive target for antiviral inhibition. Our results validate reports that the SARS-CoV-2 nsp14–nsp10 complex has RNase activity. Detailed functional characterization reveals nsp14–nsp10 is a versatile nuclease capable of digesting a wide variety of RNA structures, including those with a blocked 3′-terminus. Consistent with a role in maintaining viral genome integrity during replication, we find that nsp14–nsp10 activity is enhanced by the viral RNA-dependent RNA polymerase complex (RdRp) consisting of nsp12–nsp7–nsp8 (nsp12–7–8) and demonstrate that this stimulation is mediated by nsp8. We propose that the role of nsp14–nsp10 in maintaining replication fidelity goes beyond classical proofreading by purging the nascent replicating RNA strand of a range of potentially replication-terminating aberrations. Using our developed assays, we identify drug and drug-like molecules that inhibit nsp14–nsp10, including the known SARS-CoV-2 major protease (Mpro) inhibitor ebselen and the HIV integrase inhibitor raltegravir, revealing the potential for multifunctional inhibitors in COVID-19 treatment. 相似文献