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631.
G J Escobar P Todd R F Sattilaro 《The journal of histochemistry and cytochemistry》1977,25(7):513-524
An investigation of nonenzymatic chemical solutions for the dispersal of gynecologic cells in suspension was undertaken using known general information on the composition of cell surfaces and cell adhesive properties. Studies on human cells cultured in vitro showed that thiol reducing agents release microextension-mediated contacts. Dispersing solutions containing lithium diiodosalicylate separated cells, presumably by extracting glycoproteins. Solutions without this agent but containing tetramethylurea and mixed sugars similar to those found on the cell surface separated cells by interacting with hydrogen bonds and other noncovalent polysaccharide interactions thought to hold cells together. Solutions containing ethylenediaminetetraacetate, dithiothreitol, tetramethylurea, mixed sugars, mixed amines and inorganic ions are suggested as mildly-acting dispersal solutions on the basis of evaluationtions by phase contrast microscopy, Papanicolaou staining and particle volume analysis. 相似文献
632.
Abstract Predicting the population dynamics of insects in natural conditions is essential for their management or preservation, and temperature‐dependent development models contribute to achieving this. In this research the effects of temperature and soil moisture content on egg development and hatching of Clavipalpus ursinus (Blanchard) were evaluated. The eggs were exposed to seven temperature treatments with averages of 7.2, 13.0, 15.5, 19.7, 20.6, 22.0 and 25.3°C, in combination with three soil moisture contents of 40%, 60% and 80%. A linear and two non‐linear (Lactin and Briere) models were evaluated in order to determine the thermal requirements of this developmental stage. Temperature affected significantly the time of development and egg hatching, while no significant effect was observed for moisture content. Thermal requirements were set as: 7.2°C for lower developmental threshold, 20.6°C for optimum developmental threshold, 25.3°C for maximum temperature and 344.83 degree‐days for the thermal constant. The linear model described satisfactorily egg development at intermediate temperatures; nevertheless, a slightly better fit of the observed data was obtained with the Lactin model. Egg development took place inside a narrow range of temperatures. Consequently, an increment of soil temperature could generate a negative impact on the population size of this species or changes in its biological parameters. 相似文献
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The butyrophilin and butyrophilin-like superfamily of molecules has garnered attention in the immunology world in the past few years as a result of the observation that the butyrophilin-like 2 molecule, BTNL2, can alter T cell responsiveness. Additional interest in this superfamily solidified following the discovery that genetic polymorphisms in BTNL2 are associated with predisposition to many human diseases. In this review, we will provide an overview of the members comprising the butyrophilin superfamily of molecules. We will then discuss BTNL2 immunomodulatory function, and BTNL2 structural associations with other costimulatory molecules. We will then draw your attention to some of the lesser-known butyrophilin superfamily members by describing the expression patterns of these molecules in human tissues and cells. And we will finish by hypothesizing on the potential influence on general immune homeostasis that might be mediated by this, thus-far little-studied, family of molecules. 相似文献
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Andrew P. Stubblefield Marisa I. Escobar Eric W. Larsen 《Wetlands Ecology and Management》2006,14(4):287-302
The Upper Truckee River and Trout Creek, two major tributaries inflowing to Lake Tahoe, join to form what was historically
the largest wetland in the Sierra Nevada mountain range that separates California and Nevada (USA). In the 1950s the delta
floodplain of the Upper Truckee River was greatly reduced in area (38%) by urban development and the diversion of the river
into a single excavated channel. Conversely, Trout Creek still flows through a wide marsh system with significant overbank
flooding before entering Lake Tahoe. This study hypothesized that river channel reaches that are not incised within the delta
floodplain retain more sediment and nutrients as a result of greater floodplain connectivity, compared to more incised and
excavated reaches. Suspended sediment (SS) and total phosphorus (TP) load data from the delta formed by the Upper Truckee
River and Trout Creek were collected using flow stage sensors, turbidometers and depth-integrated samples. During the spring
snowmelt flow events monitored in 2003, SS load was reduced by 13–41% for the Upper Truckee River and by 68–90% for Trout
Creek. Similar reductions in TP load were observed: 13–32% for the Upper Truckee River and 61–84% for Trout Creek. Monitoring
of Trout Creek indicated a reduction in load per unit volume of 20–34% in a moderately incised reach versus a reduction of
51–77% in a non-incised marsh reach containing lagoons, braided channels and backwater areas created by a beaver dam. Smaller
particle sizes, <10 μm, were retained in the lower marsh reach with similar efficiencies as larger particle sizes. If retention
rates from the Trout Creek portion of the marsh are applied to the Upper Truckee River, sediment loading to Lake Tahoe for
2003 would have been reduced by 917 tons of SS. 相似文献