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81.
Twenty-eight men were given morning and afternoon oral glucose tolerance tests in 1969 and again in 1975. According to British Diabetic Association criteria all 28 had normal morning values in 1969 but seven had "afternoon diabetes". Four men had diabetic values in the morning in 1975 but only two of these had had afternoon diabetes in 1969. Better prediction of subsequent diabetes was obtained by calculating the area under the morning glucose tolerance curve in 1969. All four men who progressed to diabetes had areas exceeding 1000 units, which distinguished them absolutely from the other 24. They also tended to be more obese, but this was less predictive of subsequent diabetes.  相似文献   
82.
Fourteen patients with longstanding lipodermatosclerosis of their lower legs, secondary to venous disease in 11, were treated for three months with stanozolol, a drug that enhances fibrinolytic activity. No other treatment was given and no change made in existing treatment. All the patients improved. Two were cured in three months, three were able to stop treatment in the next three to 11 months, and the other nine continued to improve. Fibrinolytic enhancement, with stanozolol, seems to be a worthwhile addition to the treatment of venous liposclerosis and deserves further study.  相似文献   
83.
The activator of the Ca2+-stimulated ATPase of erythrocyte membranes was purified 13,000-fold to homogeneity from human erythrocytes. The protein gave a single band upon electrophoresis both with and without detergent, and upon isoelectric focusing. This protein was compared with Ca2+-binding modulator proteins from bovine brain and rat testis. All three proteins were homogeneous and co-migrated on electrophoresis both in the presence of detergent and without detergent at pH values on both sides of the isoelectric point of the protein. The amino acid compositions of the three proteins were nearly indistinguishable, and all three proteins contained 1 residue of the unusual amino acid, trimethyllysine. All three were also indistinguishable as measured by their ability to further stimulate the Ca2+-stimulated ATPase of human erythrocyte membranes. Thus, we conclude that they represent functionally the same protein. Upon storage of all three proteins, a second band was detectable by detergent gel electrophoresis; the biochemical activity and the behavior on nondetergent gels were not changed. The presence of this second band is probably responsible for previous reports of differences between the rat testis and bovine brain modulator protein. The possibility is discussed that this protein is a general intracellular Ca2+ receptor, which mediates the activities of Ca2+ as an intracellular messenger.  相似文献   
84.
Plant and fungal calmodulin: Ca2+-dependent regulation of plant NAD kinase   总被引:3,自引:0,他引:3  
Although little is known about the role(s) of second messengers, including free Ca2+, in plant cells there has been increasing evidence for a role for Ca2+ in metabolic regulation in plants. The recent demonstration that the Ca2+-binding protein, calmodulin exists in extracts of higher plants and basidiomycete fungi provides a basis for understanding Ca2+-dependent metabolic regulation in plant cells. In this review we summarize the similarities and differences of plant, fungal and mammalian calmodulin. We also discuss the known in vitro functions of calmodulin in higher plants. A Ca2+-calmodulin-dependent NAD kinase has been purified to homogeneity from extracts of pea seedlings and shown to be absolutely dependent upon calmodulin and microM levels of free Ca2+ for activity. The available evidence suggest that this Ca2+-calmodulin-dependent NAD kinase is the major form of plant NAD kinase and that this regulatory enzyme is localized in the chloroplast. A model is presented which predicts that the rate of photosynthesis is regulated by a receptor-mediated change in the level of chloroplastic free Ca2+ upon illumination. Free Ca2+, acting as a second messenger, forms a Ca2+-calmodulin complex thus converting calmodulin to its active conformation. This Ca2+-calmodulin complex then activates chloroplastic NAD kinase resulting in an increased NADP/NAD ratio.  相似文献   
85.
In 76 members of 13 large families, we investigated whether association exists between specific familialHLA haplotypes and immune responsiveness to four different highly purified pollen antigens (ragweed antigens E, Ra3, and Ra5 and rye grass Group I). Specific immune response was studied quantitatively by measurement of IgE-mediated skin sensitivity, serum IgG antibody, and antigen-induced lymphocyte proliferationin vitro. We found no evidence for association between specificHLA haplotype and specific response measured by any one or more of our indices of immune function. In several families we found evidence of specific response in one generation but not in another. We found a number of instances of individuals exhibiting lymphocyte responsiveness to an antigen, but no detectable specific IgE or IgG antibody. Surprisingly, we also found a few cases of individuals with marked IgE and/or IgG responses to a given antigen who showed no measurable lymphocyte responsiveness to that antigen, despite lymphocyte responsiveness to other nonimmunologically crossreacting antigens. In several cases, we also observed lymphocyte stimulation and serum IgG antibody, but no detectable IgE response. Our results conflict with previous investigators' reports of linkage betweenHLA haplotype and specific IgE-mediated skin sensitivity in families.HLA- linked immune response (Ir) loci may exist in humans, but genetic complexity and the limits of current technology preclude our ability to demonstrate their existence.  相似文献   
86.
Ten-year mortality rates in men aged 40-64 years in the Whitehall Study were analysed in relation to weight and height at the initial examination. At ages 40-49 "all-causes" mortality increased with increasing body mass index; but this simple relation disappeared at older ages, where there was an increased mortality in the lowest quintile of body mass index. The "all-ages" relation was "J"-shaped, and this could not be explained by the confounding effects of blood pressure, cholesterol values, and cigarette smoking. Some, but not all, of the J shape was due to a high short-term mortality in thin men from cancers (presumably already present at examination). At younger ages mortality from coronary heart disease was positively related to body mass index, but this depended on its association with other risk factors. Mortality from causes other than cancers or coronary heart disease was highest in the lowest quintile of body mass index.  相似文献   
87.
Inducible nitric oxide synthase (iNOS) plays an important role in the inflammatory process of certain major cardiac disorders including myocardial infarction and allograft rejection. However, the role of iNOS in acute myocardial ischemia has not been well defined. We determined the effects of genetically disruption of the intact iNOS system on cardiac tolerance to ischemia/reperfusion injury. Adult male wild-type (WT) and iNOS knockout (KO) B6,129 mice were subjected to 20 min global ischemia and 30 min reperfusion in a Langendorff isolated perfused heart model (37 degrees C, n = 10/each group). Ventricular contractile function, heart rate, coronary flow, and leakage of intracellular enzymes (CK and LDH) were not significantly different between the groups during pre-ischemia as well as reperfusion period (P > 0.05). Myocardial infarct size was also not significantly different between WT (20.2+/-2.0% of risk area) and KO mice (23.5+/-3.8%; Mean+/-SEM, P > 0.05). However, the post-ischemic heart rate was significantly preserved in KO as compared to WT (P < 0.05). We conclude that disruption of iNOS gene does not exacerbate ischemia/ reperfusion injury in the heart.  相似文献   
88.
A Ca(2+)-calmodulin dependent protein kinase activity (DGC-PK) was previously shown to associate with skeletal muscle dystrophin glycoprotein complex (DGC) preparations, and phosphorylate dystrophin and a protein with the same electrophoretic mobility as alpha-syntrophin (R. Madhavan, H.W. Jarrett, Biochemistry 33 (1994) 5797-5804). Here, we show that DGC-PK and Ca(2+)-calmodulin dependent protein kinase II (CaM kinase II) phosphorylate a common site (RSDS(3616)) within the dystrophin C terminal domain that fits the consensus CaM kinase II phosphorylation motif (R/KXXS/T). Furthermore, both kinase activities phosphorylate exactly the same three fusion proteins (dystrophin fusions DysS7 and DysS9, and the syntrophin fusion) out of a panel of eight fusion proteins (representing nearly 100% of syntrophin and 80% of dystrophin protein sequences), demonstrating that DGC-PK and CaM kinase II have the same substrate specificity. Complementing these results, anti-CaM kinase II antibodies specifically stained purified DGC immobilized on nitrocellulose membranes. Renaturation of electrophoretically resolved DGC proteins revealed a single protein kinase band (M(r) approximately 60,000) that, like CaM kinase II, underwent Ca(2+)-calmodulin dependent autophosphorylation. Based on these observations, we conclude DGC-PK represents a dystrophin-/syntrophin-phosphorylating skeletal muscle isoform of CaM kinase II. We also show that phosphorylation of the dystrophin C terminal domain sequences inhibits their syntrophin binding in vitro, suggesting a regulatory role for phosphorylation.  相似文献   
89.
The expectation that cell-mediated immunity is important in the control of feline leukemia virus (FeLV) infection led us to test a DNA vaccine administered alone or with cytokines that favored the development of a Th1 immune response. The vaccine consisted of two plasmids, one expressing the gag/pol genes and the other expressing the env gene of FeLV-A/Glasgow-1. The genetic adjuvants were plasmids encoding the feline cytokines interleukin-12 (IL-12), IL-18, or gamma interferon (IFN-gamma). Kittens were immunized by three intramuscular inoculations of the FeLV DNA vaccine alone or in combination with plasmids expressing IFN-gamma, IL-12, or both IL-12 and IL-18. Control kittens were inoculated with empty plasmid. Following immunization, anti-FeLV antibodies were not detected in any kitten. Three weeks after the final immunization, the kittens were challenged by the intraperitoneal inoculation of FeLV-A/Glasgow-1 and were then monitored for a further 15 weeks for the presence of virus in plasma and, at the end of the trial, for latent virus in bone marrow. The vaccine consisting of FeLV DNA with the IL-12 and IL-18 genes conferred significant immunity, protecting completely against transient and persistent viremia, and in five of six kittens protecting against latent infection. None of the other vaccines provided significant protection.  相似文献   
90.
Feline leukemia virus (FeLV) is a common naturally occurring gammaretrovirus of domestic cats that is associated with degenerative diseases of the hematopoietic system, immunodeficiency, and neoplasia. Although the majority of cats exposed to FeLV develop a transient infection and recover, a proportion of cats become persistently viremic and many subsequently develop fatal diseases. To define the dominant host immune effector mechanisms responsible for the outcome of infection, we studied the longitudinal changes in FeLV-specific cytotoxic T lymphocytes (CTLs) in a group of na?ve cats following oronasal exposure to FeLV. Using (51)Cr release assays to measure ex vivo virus-specific cytotoxicity, the emerging virus-specific CTL response was correlated with modulations in viral burden as assessed by detection of infectious virus, FeLV p27 capsid antigen, and proviral DNA in the blood. High levels of circulating FeLV-specific effector CTLs appeared before virus neutralizing antibodies in cats that recovered from exposure to FeLV. In contrast, persistent viremia was associated with a silencing of virus-specific humoral and cell-mediated host immune effector mechanisms. A single transfer of between 2 x 10(7) and 1 x 10(8) autologous, antigen-activated lymphoblasts was associated with a downmodulation in viral burden in vivo. The results suggest an important role for FeLV-specific CTLs in retroviral immunity and demonstrate the potential to modulate disease outcome by the adoptive transfer of antigen-specific T cells in vivo.  相似文献   
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