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Les N. Harris Kimberly L. Howland Matthew W. Kowalchuk Robert Bajno Melissa M. Lindsay Eric B. Taylor 《Ecology and evolution》2013,3(1):145-161
Resolving the genetic population structure of species inhabiting pristine, high latitude ecosystems can provide novel insights into the post‐glacial, evolutionary processes shaping the distribution of contemporary genetic variation. In this study, we assayed genetic variation in lake trout (Salvelinus namaycush) from Great Bear Lake (GBL), NT and one population outside of this lake (Sandy Lake, NT) at 11 microsatellite loci and the mtDNA control region (d‐loop). Overall, population subdivision was low, but significant (global FST θ = 0.025), and pairwise comparisons indicated that significance was heavily influenced by comparisons between GBL localities and Sandy Lake. Our data indicate that there is no obvious genetic structure among the various basins within GBL (global FST = 0.002) despite the large geographic distances between sampling areas. We found evidence of low levels of contemporary gene flow among arms within GBL, but not between Sandy Lake and GBL. Coalescent analyses suggested that some historical gene flow occurred among arms within GBL and between GBL and Sandy Lake. It appears, therefore, that contemporary (ongoing dispersal and gene flow) and historical (historical gene flow and large founding and present‐day effective population sizes) factors contribute to the lack of neutral genetic structure in GBL. Overall, our results illustrate the importance of history (e.g., post‐glacial colonization) and contemporary dispersal ecology in shaping genetic population structure of Arctic faunas and provide a better understanding of the evolutionary ecology of long‐lived salmonids in pristine, interconnected habitats. 相似文献
83.
Mark P. Peterson Kimberly A. Rosvall Jeong-Hyeon Choi Charles Ziegenfus Haixu Tang John K. Colbourne Ellen D. Ketterson 《PloS one》2013,8(4)
Despite sharing much of their genomes, males and females are often highly dimorphic, reflecting at least in part the resolution of sexual conflict in response to sexually antagonistic selection. Sexual dimorphism arises owing to sex differences in gene expression, and steroid hormones are often invoked as a proximate cause of sexual dimorphism. Experimental elevation of androgens can modify behavior, physiology, and gene expression, but knowledge of the role of hormones remains incomplete, including how the sexes differ in gene expression in response to hormones. We addressed these questions in a bird species with a long history of behavioral endocrinological and ecological study, the dark-eyed junco (Junco hyemalis), using a custom microarray. Focusing on two brain regions involved in sexually dimorphic behavior and regulation of hormone secretion, we identified 651 genes that differed in expression by sex in medial amygdala and 611 in hypothalamus. Additionally, we treated individuals of each sex with testosterone implants and identified many genes that may be related to previously identified phenotypic effects of testosterone treatment. Some of these genes relate to previously identified effects of testosterone-treatment and suggest that the multiple effects of testosterone may be mediated by modifying the expression of a small number of genes. Notably, testosterone-treatment tended to alter expression of different genes in each sex: only 4 of the 527 genes identified as significant in one sex or the other were significantly differentially expressed in both sexes. Hormonally regulated gene expression is a key mechanism underlying sexual dimorphism, and our study identifies specific genes that may mediate some of these processes. 相似文献
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Andrew C. Huang John E. Elliott Kimberly M. Cheng Kermit Ritland Carol E. Ritland Sarah K. Thomsen Sofi Hindmarch Kathy Martin 《Conservation Genetics》2016,17(2):357-367
The barn owl (Tyto alba) is a non-migratory species widely distributed across much of North America in areas with extensive old-field and grassland habitat and without extensive winter snow cover. We investigated the genetic diversity and phylogeographic patterns of barn owl populations in western North America, ranging from British Columbia (BC) to southern California, and one eastern population from Pennsylvania. We also determined the genetic distinctiveness of a population off the coast of southern California, Santa Barbara Island, as management plans to control the local owl population are being considered to decrease predation rate on the now threatened Scripps’s Murrelet (Synthliboramphus scrippsi). Using 8 polymorphic microsatellite markers (N = 126) and ND2 mitochondrial sequences (N = 37), we found little to no genetic structure among all sampled regions, with the exception of Santa Barbara Island. The BC mainland population, despite its northwestern geographically peripheral location and ongoing habitat degradation, is not genetically depauperate. However, individuals from Vancouver Island, likewise a peripheral population in BC, exhibited the lowest genetic diversity of all sampled locations. The low global FST value (0.028) estimated from our study suggests that old-field agricultural habitats are well connected in North America. Since the BC population has declined by about 50 % within the last three decades, it is vital to focus on preserving the remaining barn owl habitats in BC to allow successful establishment from neighbouring populations. Additionally, our microsatellite data revealed that the population on Santa Barbara Island showed genetic divergence from its continental counterpart. Mitochondrial data, however, demonstrated that this island population is not a monophyletic lineage containing unique haplotypes, and hence cannot be designated as an Evolutionarily Significant Unit. 相似文献
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Kristin Clift Kimberly Guthrie Eric W. Klee Nicole Boczek Margot Cousin Patrick Blackburn 《朊病毒》2016,10(6):502-506
Here we present a case of an asymptomatic 53-year-old woman who sought genetic testing for Familial Creutzfeldt-Jakob Disease (fCJD) after learning that her mother had fCJD. The patient's mother had a sudden onset of memory problems and rapidly deteriorating mental faculties in her late 70s, which led to difficulties ambulating, progressive non-fluent aphasia, dysphagia and death within ~1 y of symptom onset. The cause of death was reported as “rapid onset dementia.” The patient's family, unhappy with the vague diagnosis, researched prion disorders online and aggressively pursued causation and submitted frozen brain tissue from the mother to the National Prion Disease Surveillance Center, where testing revealed a previously described 5-octapeptide repeat insertion (5-OPRI) in the prion protein gene (PRNP) that is known to cause fCJD. The family had additional questions about the implications of this result and thus independently sought out genetic counseling. ?While rare, fCJD is likely underdiagnosed due to clinical heterogeneity, rapid onset, early non-specific symptomatology, and overlap in the differential diagnosis of Alzheimer disease and Lewy body dementias. When fCJD is identified, a multidisciplinary approach to return of results that includes the affected patient's provider, genetics professionals, and mental health professionals is key to the care of the family. We present an example case which discusses the psychosocial issues encountered and the role of genetic counseling in presymptomatic testing for incurable neurodegenerative conditions. Ordering physicians should be aware of the basic issues surrounding presymptomatic genetic testing and identify local genetic counseling resources for their patients. 相似文献
88.
Li Peng Kimberly Cook Linda Xu Li Cheng Melissa Damschroder Changshou Gao 《MABS-AUSTIN》2016,8(8):1598-1605
Inhibitors of tumor necrosis factor-α converting enzyme (TACE) have potential as therapeutics for various diseases. Many small molecule inhibitors, however, exhibit poor specificity profiles because they target the highly conserved catalytic cleft of TACE. We report for the first time the molecular interaction of a highly specific anti-TACE antagonistic antibody (MEDI3622). We characterized the binding of MEDI3622 using mutagenesis, as well as structural modeling and docking approaches. We show that MEDI3622 recognizes a unique surface loop of sIVa-sIVb β-hairpin on TACE M-domain, but does not interact with the conserved catalytic cleft or its nearby regions. The exquisite specificity of MEDI3622 is mediated by this distinct structural feature on the TACE M-domain. These findings may aid the design of antibody therapies against TACE. 相似文献
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Robert E. Druzinsky James P. Balhoff Alfred W. Crompton James Done Rebecca Z. German Melissa A. Haendel Anthony Herrel Susan W. Herring Hilmar Lapp Paula M. Mabee Hans-Michael Muller Christopher J. Mungall Paul W. Sternberg Kimberly Van Auken Christopher J. Vinyard Susan H. Williams Christine E. Wall 《PloS one》2016,11(2)