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Hughes LA Khalid-de Bakker CA Smits KM van den Brandt PA Jonkers D Ahuja N Herman JG Weijenberg MP van Engeland M 《Biochimica et biophysica acta》2012,1825(1):77-85
In recent years, attention has focused on the biology and potential clinical importance of the CpG island methylator phenotype (CIMP) in colorectal cancer (CRC). While it is generally well accepted that etiologically and clinically distinct subgroups exist in this disease, a precise definition of CIMP remains to be established. Here, we summarize existing literature that documents the prevalence of CIMP in CRC, with particular attention to the various methods and definitions used to classify a tumor as CIMP positive. Through a systematic review on both case-series and population based studies, we examined only original research articles reporting on sporadic CRC and/or adenomas in unselected cases. Forty-eight papers published between January 1999 and August 2011 met the inclusion criteria. We describe the use of multiple gene panels, marker threshold values, and laboratory techniques which results in a wide range in the prevalence of CIMP. Because there is no universal standard or consensus on quantifying the phenotype, establishing its true prevalence is a challenge. This bottleneck is becoming increasingly evident as molecular pathological epidemiology continues to offer possibilities for clear answers regarding environmental risk factors and disease trends. For the first time, large, unselected series of cases are available for analysis, but comparing populations and pooling data will remain a challenge unless a universal definition of CIMP and a consensus on analysis can be reached, and the primary cause of CIMP identified. 相似文献
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Christopher M. Barker Bethany G. Bolling William C. Black IV Chester G. Moore Lars Eisen 《Journal of vector ecology》2009,34(2):276-293
We conducted studies on mosquitoes and West Nile virus (WNV) along a riparian corridor following the South Platte River and Big Thompson River in northeastern Colorado and extending from an elevation of 1,215 m in the prairie landscape of the eastern Colorado plains to 1,840 m in low montane areas at the eastern edge of the Rocky Mountains in the central part of the state. Mosquito collection during June‐September 2007 in 20 sites along this riparian corridor yielded a total of 199,833 identifiable mosquitoes of 17 species. The most commonly collected mosquitoes were, in descending order: Aedes vexans, Culex tarsalis, Ae. dorsalis, Ae. trivittatus, Ae. melanimon, Cx. pipiens, and Culiseta inornata. Species richness was higher in the plains than in foothills‐montane areas, and abundances of several individual species, including the WNV vectors Cx. tarsalis and Cx. pipiens and the nuisance‐biter and potential secondary WNV vector Ae. vexans, decreased dramatically from the plains (1,215‐1,487 m) to foothills‐montane areas (1,524‐1,840 m). Ae. vexans and Cx. tarsalis had a striking pattern of uniformly high abundances between 1,200‐1,450 m followed by a gradual decrease in abundance above 1,450 m to reach very low numbers above 1,550 m. Culex species were commonly infected with WNV in the plains portion of the riparian corridor in 2007, with 14 of 16 sites yielding WNV‐infected Cx. tarsalis and infection rates for Cx. tarsalis females exceeding 2.0 per 1,000 individuals in ten of the sites. The Vector Index for abundance of WNV‐infected Cx. tarsalis females during June‐September exceeded 0.5 in six plains sites along the South Platte River but was uniformly low (0–0.1) in plains, foothills and montane sites above 1,500 m along the Big Thompson River. A population genetic analysis of Cx. tarsalis revealed that all collections from the ≈190 km riparian transect in northeastern Colorado were genetically uniform but that these collections were genetically distinct from collections from Delta County on the western slope of the Continental Divide. This suggests that major waterways in the Great Plains serve as important dispersal corridors for Cx. tarsalis but that the Continental Divide is a formidable barrier to this WNV vector. 相似文献
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A. Justin Nowakowski James I. Watling Michelle E. Thompson George A. Brusch IV Alessandro Catenazzi Steven M. Whitfield David J. Kurz Ángela Suárez‐Mayorga Andrés Aponte‐Gutiérrez Maureen A. Donnelly Brian D. Todd 《Ecology letters》2018,21(3):345-355
Human activities often replace native forests with warmer, modified habitats that represent novel thermal environments for biodiversity. Reducing biodiversity loss hinges upon identifying which species are most sensitive to the environmental conditions that result from habitat modification. Drawing on case studies and a meta‐analysis, we examined whether observed and modelled thermal traits, including heat tolerances, variation in body temperatures, and evaporative water loss, explained variation in sensitivity of ectotherms to habitat modification. Low heat tolerances of lizards and amphibians and high evaporative water loss of amphibians were associated with increased sensitivity to habitat modification, often explaining more variation than non‐thermal traits. Heat tolerances alone explained 24–66% (mean = 38%) of the variation in species responses, and these trends were largely consistent across geographic locations and spatial scales. As habitat modification alters local microclimates, the thermal biology of species will likely play a key role in the reassembly of terrestrial communities. 相似文献
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This study explored consumer liking and perception of pork patties with an added functional health ingredient: shiitake (Lentinus edodes P.) mushroom powder. In addition, patties with and without sodium tripolyphosphate were tested. Both native Korean and U.S. consumers evaluated the products. Pork patties made with both phosphate and mushroom powder were found to be acceptable by Korean consumers, but increases in mushroom powder in patties with phosphate decreased acceptability for U.S. consumers. However, addition of mushroom powder to patties without phosphate increased acceptability for U.S. consumers, perhaps because it tended to increase texture acceptance and juiciness. Thus, addition of mushroom powder as a functional ingredient in pork patties, while possible, would require different formula modifications to appeal to consumers of differing nationalities. 相似文献
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Michael G. Hanna IV Ioanna Mela Lei Wang Robert M. Henderson Edwin R. Chapman J. Michael Edwardson Anjon Audhya 《The Journal of biological chemistry》2016,291(3):1014-1027
The majority of biosynthetic secretory proteins initiate their journey through the endomembrane system from specific subdomains of the endoplasmic reticulum. At these locations, coated transport carriers are generated, with the Sar1 GTPase playing a critical role in membrane bending, recruitment of coat components, and nascent vesicle formation. How these events are appropriately coordinated remains poorly understood. Here, we demonstrate that Sar1 acts as the curvature-sensing component of the COPII coat complex and highlight the ability of Sar1 to bind more avidly to membranes of high curvature. Additionally, using an atomic force microscopy-based approach, we further show that the intrinsic GTPase activity of Sar1 is necessary for remodeling lipid bilayers. Consistent with this idea, Sar1-mediated membrane remodeling is dramatically accelerated in the presence of its guanine nucleotide-activating protein (GAP), Sec23-Sec24, and blocked upon addition of guanosine-5′-[(β,γ)-imido]triphosphate, a poorly hydrolysable analog of GTP. Our results also indicate that Sar1 GTPase activity is stimulated by membranes that exhibit elevated curvature, potentially enabling Sar1 membrane scission activity to be spatially restricted to highly bent membranes that are characteristic of a bud neck. Taken together, our data support a stepwise model in which the amino-terminal amphipathic helix of GTP-bound Sar1 stably penetrates the endoplasmic reticulum membrane, promoting local membrane deformation. As membrane bending increases, Sar1 membrane binding is elevated, ultimately culminating in GTP hydrolysis, which may destabilize the bilayer sufficiently to facilitate membrane fission. 相似文献