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991.
The global distribution of the reddish egret is characterized by disjunct colonies occurring from the Pacific side of Northwest
Mexico to the Caribbean. We examined distantly isolated colonies of reddish egret to determine global population genetic structure.
We used seven polymorphic microsatellites to accomplish five goals: (1) to assess range wide population differentiation among
reddish egret (Egretta rufescens) populations, (2) identify extent of gene flow, (3) determine any historical occurrence of bottlenecks, (4) assess genetic
differentiation between color morphs, (5) clarify subspecies status of E.
r. dickeyi, a completely dark morph population located in and around the Baja California peninsula, Mexico. Genetic differentiation was
dramatic (global Fst = 0.161) throughout the reddish egrets range extending from Baja California, Mexico to Great Inagua,
Bahamas. Differentiation occurred among three distinct regions (Fst = 0.238) but not among colonies/islands within regions
suggesting regional philopatry. Genetic diversity (alleles per locus, and heterozygosity) in Baja California Sur, Mexico and
Great Inagua, Bahamas populations is lower than in the Texas/Mexico population due to minimal dispersal between regions and
smaller population sizes. Dark and white color morphs when present within the same region showed no differentiation. Patterns
of recent population bottlenecks are not evident in each of the three regional populations. With evidence of limited gene
flow in addition to low genetic diversity and prospects of habitat loss we recommend that reddish egrets be managed as three
distinct or evolutionary significant units. 相似文献
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993.
Prema Robinson Armandina Garza Joel Weinstock Jose A. Serpa Jerry Clay Goodman Kristian T. Eckols Bahrom Firozgary David J. Tweardy 《PLoS pathogens》2012,8(2)
Neurocysticercosis (NCC), a helminth infection of the brain, is a major cause of seizures. The mediators responsible for seizures in NCC are unknown, and their management remains controversial. Substance P (SP) is a neuropeptide produced by neurons, endothelial cells and immunocytes. The current studies examined the hypothesis that SP mediates seizures in NCC. We demonstrated by immunostaining that 5 of 5 brain biopsies from NCC patients contained substance P (SP)-positive (+) cells adjacent to but not distant from degenerating worms; no SP+ cells were detected in uninfected brains. In a rodent model of NCC, seizures were induced after intrahippocampal injection of SP alone or after injection of extracts of cysticercosis granuloma obtained from infected wild type (WT), but not from infected SP precursor-deficient mice. Seizure activity correlated with SP levels within WT granuloma extracts and was prevented by intrahippocampal pre-injection of SP receptor antagonist. Furthermore, extracts of granulomas from WT mice caused seizures when injected into the hippocampus of WT mice, but not when injected into SP receptor (NK1R) deficient mice. These findings indicate that SP causes seizures in NCC, and, suggests that seizures in NCC in humans may be prevented and/or treated with SP-receptor antagonists. 相似文献
994.
Virginia A Folcik Gordon Broderick Shunmugam Mohan Brian Block Chirantan Ekbote John Doolittle Marc Khoury Luke Davis Clay B Marsh 《Theoretical biology & medical modelling》2011,8(1):1
Background
The immune system behaves like a complex, dynamic network with interacting elements including leukocytes, cytokines, and chemokines. While the immune system is broadly distributed, leukocytes must communicate effectively to respond to a pathological challenge. The Basic Immune Simulator 2010 contains agents representing leukocytes and tissue cells, signals representing cytokines, chemokines, and pathogens, and virtual spaces representing organ tissue, lymphoid tissue, and blood. Agents interact dynamically in the compartments in response to infection of the virtual tissue. Agent behavior is imposed by logical rules derived from the scientific literature. The model captured the agent-to-agent contact history, and from this the network topology and the interactions resulting in successful versus failed viral clearance were identified. This model served to integrate existing knowledge and allowed us to examine the immune response from a novel perspective directed at exploiting complex dynamics, ultimately for the design of therapeutic interventions. 相似文献995.
996.
The effects of potassium hydroxide and soidum methoxide treatments upon the Alcian blue staining and neuraminidase lability of certain neuraminidase resistant epithelial mucins have been studied. The results were interpreted as indicating that while the mucins of rat colon and rabbit Brunner's gland contain only 4-0-acetyl sialic acid, human colonic epithelial mucins may contain some sialic acid with esters at the C1 carboxyl group. 相似文献
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Clay M. Armstrong 《The Journal of general physiology》1997,109(5):523-524