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11.
Jacob D. Hennig J. D. Scasta Aaron C. Pratt Caitlyn P. Wanner Jeffrey L. Beck 《The Journal of wildlife management》2023,87(1):e22329
Populations of feral horses (Equus ferus caballus) in the western United States have increased during the past decade, consequently affecting co-occurring wildlife habitat. Feral horses may influence 2 native wildlife species, greater sage-grouse (Centrocercus urophasianus; sage-grouse) and pronghorn (Antilocapra americana) through mechanisms of habitat alteration and competition. Wyoming, USA, contains the largest populations of pronghorn and sage-grouse of any state and also has the highest degree of range overlap between feral horses and these species. Consequently, the effects that horses may have on pronghorn and sage-grouse populations in Wyoming have implications at local, state, and population-wide levels. Managers need information concerning habitat selection and space use overlap among these species to develop appropriate management strategies; yet this information is absent for most feral horse management areas. To address this knowledge need, we attached global positioning system (GPS) transmitters to horses, pronghorn, and sage-grouse within the greater Bureau of Land Management–Adobe Town Herd Management Area in southern Wyoming and northern Colorado, USA, between 2017 and 2021 to evaluate habitat selection and space use of all species during 3 biologically relevant seasons: spring (Apr–Jun; sage-grouse breeding, nesting, and early-brood rearing; pronghorn late gestation and early parturition), summer (Jul–Oct; sage-grouse summer and late-brood rearing; pronghorn late parturition and breeding), and winter (Nov–Mar; non-breeding season). Feral horses selected flatter slopes and shorter mean shrub height across all seasons and were closer to water in spring and summer. Pronghorn habitat selection was similar to horses, but they also avoided oil and gas well pads year-round. During spring, sage-grouse selected greater herbaceous cover, flatter slopes, and areas farther from well pads. In summer, sage-grouse selected greater mean shrub height, flatter slopes, and were closer to water. In winter, sage-grouse selected flatter slopes and areas with greater vegetation production during the preceding summer. Our results indicate strong year-round overlap in space use between horses and pronghorn, whereas overlap between horses and sage-grouse is greatest during the summer in this region. Consequently, managers should recognize the potential for horses to influence habitat quality of pronghorn and sage-grouse in the region. 相似文献
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Temperature-Dependent Induction of Salicylic Acid and Its Conjugates during the Resistance Response to Tobacco Mosaic Virus Infection 总被引:19,自引:0,他引:19 下载免费PDF全文
Increases in endogenous salicylic acid (SA) levels and induction of several families of pathogenesis-related genes (PR-1 through PR-5) occur during the resistance response of tobacco to tobacco mosaic virus infection. We found that at temperatures that prevent the induction of PR genes and resistance, the increases in SA levels were eliminated. The addition of exogenous SA to infected plants at these temperatures was sufficient to induce the PR genes but not the hypersensitive response. However, when the resistance response was restored by shifting infected plants to permissive temperatures, SA levels increased dramatically and preceded PR-1 gene expression and necrotic lesion formation associated with resistance. SA was also found in a conjugated form whose levels increased in parallel with the free SA levels. The majority of the conjugates appeared to be SA glucosides. The same glucoside was formed when plants were supplied with exogenous SA. These results provide further evidence that endogenous SA signals the induction of certain defense responses and suggests additional complexity in the modulation of this signal. 相似文献
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Santhini Ramasamy Gilbert A. Boissonneault Eric A. Decker Bernhard Hennig 《Journal of biochemical and molecular toxicology》1991,6(1):29-35
High plasma levels of linoleic acid (18:2) may injure endothelial cells, resulting in decreased barrier function of the vascular endothelium. The effects of linoleic acid on endothelial barrier function (transendothelial movement of albumin), membrane-bound enzyme activities, and possible autooxidation of linoleic acid under experimental conditions were studied. The exposure of endothelial monolayers to 18:2 for 24 hr at 60, 90, and 120 μM. fatty acid concentrations caused a significant increase in transendothelial movement of albumin, with maximum albumin transfer at 90 μM. Fatty acid treatment resulted in the increased appearance of cytosolic lipid droplets. Activities of the membrane-bound enzymes, angiotensin-converting enzyme (ACE), and Ca2+-ATPase increased steadily with increasing time of cell exposure to 90 μM 18:2, reaching significance at 24 hr. Treatment of endothelial cultures with up to 120 μM 18:2 did not cause cytotoxicity, as evidenced by a nonsignificant change in cellular release of [3H]-adenine. Incubation of 18:2-supplemented serum-containing culture media with 1000 μM 18:2 at 37°C for up to 48 hr did not result in formation of autooxidation products. These results suggest that 18:2 itself, and not its oxidation products, plays a major role in disrupting endothelial barrier function. 相似文献
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A Hennig R Krueger D Mangoura N B Schwartz 《Cellular and molecular biology, including cyto-enzymology》1992,38(5-6):585-593
Proteoglycans of developing chick brain were distinguished on the basis of reactivity with four well characterized antibody reagents (S103L, to the CS-rich domain; HNK-1, to 6-sulfated glucuronic acid; 1-C-3, to the HABr region and 5-D-4, to KS chains). One chondroitin sulfate proteoglycan reacted exclusively with S103L and 1-C-3 and not with the other two antibodies, hence is designated the S103L reactive brain CSPG. The other proteoglycan reacted exclusively with HNK-1 and 5-D-4 and not with S103L and 1-C-3, hence it is designated the HNK-1 reactive brain CSPG. In addition to these immunological distinctions, the S103L and HNK-1 CSPGs exhibited significant biochemical differences at both the protein and carbohydrate levels. Most interestingly, both CSPGs were found in all regions of the brain, and were expressed in a developmentally regulated pattern. The S103L CSPG was not detectable prior to embryonic day 7, increased to a maximum at day 13-15 and declined by day 20 in most brain regions examined. In contrast, the HNK-1 CSPG was present as early as embryonic day 4 and remained constant through hatching. Neuronal cultures established from embryonic day 6 (E6) cerebral hemispheres represent an in vitro paradigm that mimics in vivo neuronal development and differentiation. In this culture system we found that the expression of the S103L and HNK-1 CSPG followed a pattern similar to that observed in developing brain and further, that neurons are probably the sole source of S103L CSPG in cerebral cortex during neuroembryogenesis. 相似文献
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K D?uzniewska D Tylek K Baranowska R Drozdz J Hennig B Ho?yńska B Ostachowicz M Zysiak A Potocki J Pu?ka 《Endokrynologia Polska》1991,42(2):241-251
Following the Czernobyl accident, an epidemiologic study was undertaken in which the daily iodine intake was estimated in 15% of the population studied. Iodine excretion was measured in single morning urine specimens. The iodine content was also assessed in the water form wells and in cow-milk at farms in randomly chosen villages in the region of Krynica and Nowy Sacz. On the basis of a 24-hour diet recall, the mass of each food product consumed daily was estimated for 483 persons in the Kraków voivodship (14.4% of the total population) and for 397 persons in the Nowy Sacz voivodship (15.8% of the total population). Using this data, the nutrient content of the daily diet was calculated for each studied individual. Measurements of iodine content in water and cow-milk show relatively lower iodine levels in the Nowy Sacz voivodship. The estimated value of the iodine content in milk (5.5 micrograms/100 g of milk) was considered in the estimates of the chemical composition of the daily diet of the inhabitants of this region. The mean values of the daily energy as well as the protein and calcium consumption in all subpopulations grouped with respect to domicile, age and sex, fell within the recommended daily allowances for these groups. The iodine content, while widely scattered, concentrated around low values. The median values of the iodine content in children of age 3-10 years, age 10-16 years and in adults, were 66%, 48% and 25-40% of the recommended daily allowances, respectively. No particular differences in the food intakes were observed between inhabitants of Kraków and Nowy Sacz voivodships. Nor were significant differences found in the urine iodine excretion in groups of these regions. The low iodine content in the daily food intake may be an essential factor in the ethiology of the increasing number of thyroid goiter. 相似文献
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