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21.
R.L. Horst B.C. Pramanik T.A. Reinhardt S.-J. Shiuey J.J. Partridge M.R. Uskokovic J.L. Napoli 《Biochemical and biophysical research communications》1982,106(3):1006-1011
23,25-Dihydroxyvitamin D3 was isolated from the plasma of vitamin D3-toxic pigs. An ultraviolet absorbance spectrum confirmed its purity. The configuration of the 23-hydroxyl group was determined to be S by comparison of the natural product with synthetic 23,25- and 23,25-dihydroxyvitamin D3 by high-pressure liquid chromatography. The affinity of both 23,25- and 23,25-dihydroxyvitamin D3 for the plasma vitamin D binding protein was similar to vitamin D3. Thus, with respect to the plasma vitamin D binding protein, 23,25-dihydroxyvitamin D3 is the least potent, naturally-occurring, dihydroxylated vitamin D3 metabolite known. 相似文献
22.
Timothy A. Reinhardt Ronald L. Horst E.Travis Littledike Donald C. Beitz 《Biochemical and biophysical research communications》1982,106(3):1012-1018
1,25-Dihydroxyvitamin D3 [1,25-(OH)2D3] receptor was characterized after partial purification of thymus cytosol by ammonium sulfate fractionation. The 1,25-(OH)2D3 receptor sediments at 3.7S in 5–20% sucrose gradients. The binding of 1,25-(OH)2D3 in thymic cytosol was a saturable process with high affinity (Kd = 0.12?0.48 nM) at 4°C. Competition for 1,25-(OH)2[3H]D3 receptor by nonradioactive analogs demonstrated the affinities of these analogs to be in order; 1,25-(OH)2D3 = 1,24R,25-(OH)3D3 = 1,25S,26-(OH)3D3 = 1,25R,26-(OH)3D3 > 1,25-(OH)2D3-26,23 lactone > 25-OHD3 > 23R,25-(OH)2D3 > 24R,25-(OH)2D3 > 23S,25-(OH)2D3 ? 25-OHD3-26,23 lactone. The receptor bound to DNA cellulose columns in low salt buffer and eluted as a single peak at 0.21 M KCl. These findings provide evidence that the thymus possesses a 1,25-(OH)2D3 receptor with properties indistinguishable from 1,25-(OH)2D3 receptors in other tissues. 相似文献
23.
Jill E. Maddison Wendy E. J. Watson Peter R. Dodd Graham A. R. Johnston 《Journal of neurochemistry》1991,56(6):1881-1888
Excitatory amino acid receptor binding parameters were investigated in a spontaneous dog model of chronic hepatic encephalopathy. L-[3H]Glutamate, (+)-[3H]-5-methyl-10,11-dihydro-5H-dibenzo[a,d]cyclohepten-5,10-im ine maleate ([3H]MK-801), [3H]kainate, and alpha-[3H]-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid ([3H]AMPA) binding experiments were performed using crude cerebrocortical synaptosomal membrane preparations from dogs with congenital portosystemic encephalopathy (PSE) and control dogs. There was no change in the affinity or density of L-[3H]-glutamate or [3H]MK-801 binding sites in dogs with congenital PSE compared with control dogs. However, in the PSE dogs there was a significant reduction in the density of [3H]kainate binding sites compared with control dogs and abolition of the low-affinity [3H]AMPA binding site. The relative binding capacity of PSE synaptosomal membranes for [3H]kainate and [3H]AMPA was expressed as the ratio Bmax/KD. There was a significant inverse correlation between the Bmax/KD ratio for [3H]AMPA binding and the worst grade of encephalopathy experienced by each dog. These results suggest that there is a significant perturbation of cerebrocortical non-N-methyl-D-aspartate receptor binding in dogs with congenital PSE which may have relevance to the pathogenesis of hepatic encephalopathy. 相似文献
24.
Nanako Shigesada 《Journal of mathematical biology》1980,9(1):85-96
Summary A mathematical model for the dispersal of an animal population is presented for a system in which animals are initially released in the central region of a uniform field and migrate randomly, exerting mutually repulsive influences (population pressure) until they eventually become sedentary. The effect of the population pressure, which acts to enhance the dispersal of animals as their density becomes high, is modeled in terms of a nonlinear-diffusion equation. From this model, the density distribution of animals is obtained as a function of time and the initial number of released animals. The analysis of this function shows that the population ultimately reaches a nonzero stationary distribution which is confined to a finite region if both the sedentary effect and the population pressure are present. Our results are in good agreement with the experimental data on ant lions reported by Morisita, and we can also interpret some general features known for the spatial distribution of dispersing insects. 相似文献
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A S Hall 《Journal of medical primatology》1983,12(3):155-159
Managers of primate colonies seek to record colony data in a systematic way which will be helpful in daily management. Each colony develops individual record systems, tailored to its specific operations and budget. These diversified systems provide the base for a set of uniform record items, which enables information to be shared among institutions, and used for the overall management of a self-sustaining captive primate population, as well as for national planning of primate resources. The present report identifies basic information needed for local colony management and data items that require standard nomenclature. Such data will provide the basic demographic profiles unavailable at most primate colonies today. 相似文献
27.
《Saudi Journal of Biological Sciences》2022,29(6):103307
Malathion (MAL) is an organophosphate insecticide that disrupts the body's antioxidant system; it is one of the earliest organophosphate insecticides extensively used as dust, emulsion, and vapor control a wide variety of insect pests under different conditions. This experimentation aims to evaluate the influence of Arabica coffee oil and olive oil on MAL-induced nephrotoxicity in male rat. 6 sets bearing the same number of animals were applied to this experiment. Each set comprised 10 rats. The first set of rats was used as the control group; rats in the second set were exposed to MAL measured at 100 mg/kg body weight for 7 weeks. Animals in the third and fourth set were treated with 400 mg/kg body weight of Arabica coffee oil and olive oil, and 100 mg/kg body weight of MAL. The fifth, together with the sixth set, were fed with a similar proportion of Arabica coffee oil and olive oil as administered to the third set of rats. After the experimental duration, rats of group 2 showed severe biochemical alterations, including significant increases of creatinine, uric acids, and urea nitrogen (BUN), resulting in marked decreases in serum albumin values and total protein (TP). Severe histopathological and immunohistochemical alterations of kidney tissues were observed in exposed MAL-intoxicated rats. Administration of these oils reduced the detected biochemical, histopathological modifications caused by MAL intoxication. Two active ingredients in Arabica coffee oil (oleic acid) and olive oil (hydroxytyrosol) showed good cyclooxygenase-2 (COX 2) interaction. Moreover, oleic acid from coffee oil and olive oil exhibited impressive association with xanthine oxidase (XO). The current finding showed that coffee oil and olive oil could be appraised as possible and a likely deterrence component against nephrotoxicity brought about by MAL. 相似文献
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Singh Ashutosh Singh Rahul Soloman Sarma Phulen Batra Gitika Joshi Rupa Kaur Hardeep Sharma Amit Raj Prakash Ajay Medhi Bikash 《中国病毒学》2020,35(3):290-304
The recent outbreak of coronavirus disease(COVID-19) caused by the novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) has already affected a large population of the world. SARS-CoV-2 belongs to the same family of severe acute respiratory syndrome coronavirus(SARS-CoV) and Middle East respiratory syndrome coronavirus(MERSCoV). COVID-19 has a complex pathology involving severe acute respiratory infection, hyper-immune response, and coagulopathy. At present, there is no therapeutic drug or vaccine approved for the disease. There is an urgent need for an ideal animal model that can reflect clinical symptoms and underlying etiopathogenesis similar to COVID-19 patients which can be further used for evaluation of underlying mechanisms, potential vaccines, and therapeutic strategies. The current review provides a paramount insight into the available animal models of SARS-CoV-2, SARS-CoV, and MERS-CoV for the management of the diseases. 相似文献