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41.
Distribution, movements, and habitat use of 10 wild adult razorback suckers ( Xyrauchen texanus ) were examined in Lake Mohave, Arizona-Nevada, from November 1994 through July 1997. Movement rates (0.00-17.35 km d -1 ) and ranges ( x = 39 km) were similar to those for riverine populations. All study fish returned to spawning sites used in previous years, but they also visited other spawning areas. Spawning females were significantly ( P = 0.031) more active than males (480 vs. 87 m d -1 ) and moved substantial distances between spawning sites during peak reproduction (1-28 February). Fish became most active (m d -1 , km month -1 ) after spawning and moved to areas known to support higher algal production. Fish were typically within 50 m ( P 30.0 m). Adults were detected throughout the available thermal gradient (12°-30°C), but during summer typically had body temperatures between 18° and 22°C. Vertical movements within the water column showed no correlation with depth or time of day, but seasonal shifts suggest fish may regulate body temperature by seeking specific temperatures during reservoir stratification. 相似文献
42.
Pattern recognition receptors are somatically encoded and participate in the innate immune responses of a host to microbes.
It is increasingly acknowledged that these receptors play a central role both in beneficial and pathogenic interactions with
microbes. In particular, these receptors participate actively in shaping the gut environment to establish a fruitful life-long
relationship between a host and its microbiota. Commensal bacteria engage Toll-like receptors (TLRs) and nucleotide oligomerization
domain (NOD)-like receptors (NLRs) to induce specific responses by intestinal epithelial cells such as production of antimicrobial
products or of a functional mucus layer. Furthermore, a complex crosstalk between intestinal epithelial cells and the immune
system is initiated leading to a mature gut-associated lymphoid tissue to secrete IgA. Impairment in NLR and TLR functionality
in epithelial cells is strongly associated with chronic inflammatory diseases such as Crohn’s disease, cancer, and with control
of the commensal microbiota creating a more favorable environment for the emergence of new infections. 相似文献
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G. P. Mueller 《Cellular and molecular life sciences : CMLS》1962,18(6):253-254
Zusammenfassung Die Beweggründe für den Gebrauch derD- undL-Konvention in der Nomenklatur der Steroid-Sapogenine sowie ihre Anwendung auf die Konfigurationsanalyse und Formelaufstellung werden diskutiert. 相似文献
45.
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Zusammenfassung Es werden Einzelheiten für den Gebrauch von Spirostan und Furostan, wenn nötig durch die Präfixe 5, 5, 25R und 25S modifiziert, für die Benennung der Steroid-Sapogenine bekanntgegeben. Diese Vorschläge sollen als formale Grundlage zur Nomenklatur gelten.
A summary of the personal views of the authors, Presented by the authors to anad hoc Committee on Steroid Nomenclature (sponsored by the National Academy of Sciences and the National Research Council, and supported by a grant from the U.S. Air Force Office of Scientific Research) that met in Columbus, Ohio, October 13–15, (1961), under the chairmanship ofR. C. Elderfield. 相似文献
A summary of the personal views of the authors, Presented by the authors to anad hoc Committee on Steroid Nomenclature (sponsored by the National Academy of Sciences and the National Research Council, and supported by a grant from the U.S. Air Force Office of Scientific Research) that met in Columbus, Ohio, October 13–15, (1961), under the chairmanship ofR. C. Elderfield. 相似文献
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A key event in the response of cells to proliferative signals is the rapid, transient induction of the c-fos proto-oncogene, which is mediated through the serum response element (SRE) in the fos promoter. Genomic footprinting and transfection experiments suggest that this activation occurs through a ternary complex that includes the serum response factor (SRF) and the ternary complex factor p62. Interaction of p62TCF with the SRF-SRE binary complex requires a CAGGA tract immediately upstream of the SRE. Proteins of the ets proto-oncogene family bind to similar sequences and we have found that a member of this family, Elk-1, forms SRF-dependent ternary complexes with the SRE. Elk-1 and p62TCF have the same DNA sequence requirements and antibodies against Elk-1 block the binding of both proteins. Furthermore, we show that like p62TCF, Elk-1 forms complexes with the yeast SRF-homologue MCM1 but not with yeast ARG80. But ARG80 mutants that convey interaction with p62TCF can also form complexes with Elk-1. The similarity, or even identity, between Elk-1 and p62TCF suggests a novel regulatory role for Ets proteins that is effected through interaction with other proteins, such as SRF. Furthermore, the possible involvement of an Ets protein in the control of c-fos has interesting implications for proto-oncogene cooperation in cellular growth control. 相似文献
49.
Gebhardt T Whitney PG Zaid A Mackay LK Brooks AG Heath WR Carbone FR Mueller SN 《Nature》2011,477(7363):216-219
Infections localized to peripheral tissues such as the skin result in the priming of T-cell responses that act to control pathogens. Activated T cells undergo migrational imprinting within the draining lymph nodes, resulting in memory T cells that provide local and systemic protection. Combinations of migrating and resident memory T cells have been implicated in long-term peripheral immunity, especially at the surfaces that form pathogen entry points into the body. However, T-cell immunity consists of separate CD4(+) helper T cells and CD8(+) killer T cells, with distinct effector and memory programming requirements. Whether these subsets also differ in their ability to form a migrating pool involved in peripheral immunosurveillance or a separate resident population responsible for local infection control has not been explored. Here, using mice, we show key differences in the migration and tissue localization of memory CD4(+) and CD8(+) T cells following infection of the skin by herpes simplex virus. On resolution of infection, the skin contained two distinct virus-specific memory subsets; a slow-moving population of sequestered CD8(+) T cells that were resident in the epidermis and confined largely to the original site of infection, and a dynamic population of CD4(+) T cells that trafficked rapidly through the dermis as part of a wider recirculation pattern. Unique homing-molecule expression by recirculating CD4(+) T effector-memory cells mirrored their preferential skin-migratory capacity. Overall, these results identify a complexity in memory T-cell migration, illuminating previously unappreciated differences between the CD4(+) and CD8(+) subsets. 相似文献
50.