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91.
92.
Functional atlas of the integrin adhesome 总被引:12,自引:0,他引:12
A detailed depiction of the 'integrin adhesome', consisting of a complex network of 156 components linked together and modified by 690 interactions is presented. Different views of the network reveal several functional 'subnets' that are involved in switching on or off many of the molecular interactions within the network, consequently affecting cell adhesion, migration and cytoskeletal organization. Examination of the adhesome network motifs reveals a relatively small number of key motifs, dominated by three-component complexes in which a scaffolding molecule recruits both a signalling molecule and its downstream target. We discuss the role of the different network modules in regulating the structural and signalling functions of cell-matrix adhesions. 相似文献
93.
94.
Tomio Umemoto Savitha Subramanian Yilei Ding Leela Goodspeed Shari Wang Chang Yeop Han Antonio Sta. Teresa Jinkyu Kim Kevin D. O'Brien Alan Chait 《Journal of lipid research》2012,53(11):2380-2389
Adipose tissue inflammation is associated with insulin resistance and increased cardiovascular disease risk in obesity. We previously showed that addition of cholesterol to a diet rich in saturated fat and refined carbohydrate significantly worsens dyslipidemia, insulin resistance, adipose tissue macrophage accumulation, systemic inflammation, and atherosclerosis in LDL receptor-deficient (Ldlr−/−) mice. To test whether inhibition of intestinal cholesterol absorption would improve metabolic abnormalities and adipose tissue inflammation in obesity, we administered ezetimibe, a dietary and endogenous cholesterol absorption inhibitor, to Ldlr−/− mice fed chow or high-fat, high-sucrose (HFHS) diets without or with 0.15% cholesterol (HFHS+C). Ezetimibe blunted weight gain and markedly reduced plasma lipids in the HFHS+C group. Ezetimibe had no effect on glucose homeostasis or visceral adipose tissue macrophage gene expression in the HFHS+C fed mice, although circulating inflammatory markers serum amyloid A (SSA) and serum amyloid P (SSP) levels decreased. Nevertheless, ezetimibe treatment led to a striking (>85%) reduction in atherosclerotic lesion area with reduced lesion lipid and macrophage content in the HFHS+C group. Thus, in the presence of dietary cholesterol, ezetimibe did not improve adipose tissue inflammation in obese Ldlr−/− mice, but it led to a major reduction in atherosclerotic lesions associated with improved plasma lipids and lipoproteins. 相似文献
95.
Zhao M Batista A Cunningham JP Chestek C Rivera-Alvidrez Z Kalmar R Ryu S Shenoy K Iyengar S 《Journal of computational neuroscience》2012,32(3):479-497
Interactions among neurons are a key component of neural signal processing. Rich neural data sets potentially containing evidence
of interactions can now be collected readily in the laboratory, but existing analysis methods are often not sufficiently sensitive
and specific to reveal these interactions. Generalized linear models offer a platform for analyzing multi-electrode recordings
of neuronal spike train data. Here we suggest an L
1-regularized logistic regression model (L
1
L method) to detect short-term (order of 3 ms) neuronal interactions. We estimate the parameters in this model using a coordinate
descent algorithm, and determine the optimal tuning parameter using a Bayesian Information Criterion. Simulation studies show
that in general the L
1
L method has better sensitivities and specificities than those of the traditional shuffle-corrected cross-correlogram (covariogram)
method. The L
1
L method is able to detect excitatory interactions with both high sensitivity and specificity with reasonably large recordings,
even when the magnitude of the interactions is small; similar results hold for inhibition given sufficiently high baseline
firing rates. Our study also suggests that the false positives can be further removed by thresholding, because their magnitudes
are typically smaller than true interactions. Simulations also show that the L
1
L method is somewhat robust to partially observed networks. We apply the method to multi-electrode recordings collected in
the monkey dorsal premotor cortex (PMd) while the animal prepares to make reaching arm movements. The results show that some
neurons interact differently depending on task conditions. The stronger interactions detected with our L
1
L method were also visible using the covariogram method. 相似文献
96.
Several proteins with limited cell type distribution have been shown to bind lactoferrin. However, except in the case of hepatic and intestinal cells, these have not been definitively identified and characterized. Here we report that the multifunctional glycolytic protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH) functions as a novel receptor for lactoferrin (Lf) in macrophages. GAPDH is a well-known moonlighting protein, and previous work from our laboratory has indicated its localization on macrophage cell surfaces, wherein it functions as a transferrin (Tf) receptor. The K(D) value for GAPDH-lactoferrin interaction was determined to be 43.8 nmol/L. Utilizing co-immunoprecipitation, immunoflorescence, and immunogold labelling electron microscopy we could demonstrate the trafficking of lactoferrin to the endosomal compartment along with GAPDH. We also found that upon iron depletion the binding of lactoferrin to macrophage cell surface is enhanced. This correlated with an increased expression of surface GAPDH, while other known lactoferrin receptors CD14 and lipoprotein receptor-related protein (LRP) were found to remain unaltered in expression levels. This suggests that upon iron depletion, cells prefer to use GAPDH to acquire lactoferrin. As GAPDH is an ubiquitously expressed molecule, its function as a receptor for lactoferrin may not be limited to macrophages. 相似文献
97.
Okazaki T Pendleton CD Sarobe P Thomas EK Iyengar S Harro C Schwartz D Berzofsky JA 《Journal of immunology (Baltimore, Md. : 1950)》2006,176(6):3753-3759
Virus-specific CD4+ T cell help and CD8+ cytotoxic T cell responses are critical for maintenance of effective immunity in chronic viral infections. The importance of CD4+ T cells has been documented in HIV infection. To investigate whether a stronger CD4+ T cell response can be induced by modifications to enhance the T1 epitope, the first CD4+ T cell epitope discovered in HIV-1-gp120, we developed a T1-specific CD4+ T cell line from a healthy volunteer immunized with a canarypox vector expressing gp120 and boosted with recombinant gp120. This T1-specific CD4+ T cell line was restricted to DR13, which is common in U.S. Caucasians and African-Americans and very frequent in Africans. Peptides with certain amino acid substitutions in key positions induced enhanced specific CD4+ T cell proliferative responses at lower peptide concentration than the original epitope. This relatively conserved CD4 epitope improved by the epitope enhancement strategy could be a component of a more effective second generation vaccine construct for HIV infection. 相似文献
98.
Many reactions within the cell occur only in specific intracellular regions. Such local reaction networks give rise to microdomains of activated signaling components. The dynamics of microdomains can be visualized by live cell imaging. Computational models using partial differential equations provide mechanistic insights into the interacting factors that control microdomain dynamics. The mathematical models show that, for membrane-initiated signaling, the ratio of the surface area of the plasma membrane to the volume of the cytoplasm, the topology of the signaling network, the negative regulators, and kinetic properties of key components together define microdomain dynamics. Thus, patterns of locally restricted signaling reaction systems can be considered an emergent property of the cell. 相似文献
99.
John Paul SanGiovanni Dan E. Arking Sudha K. Iyengar Michael Elashoff Traci E. Clemons George F. Reed Alice K. Henning Theru A. Sivakumaran Xuming Xu Andrew DeWan Elvira Agrón Elena Rochtchina Carolyn M. Sue Jie Jin Wang Paul Mitchell Josephine Hoh Peter J. Francis Michael L. Klein Emily Y. Chew Aravinda Chakravarti 《PloS one》2009,4(5)
Background
Age-related macular degeneration (AMD), a chronic neurodegenerative and neovascular retinal disease, is the leading cause of blindness in elderly people of western European origin. While structural and functional alterations in mitochondria (mt) and their metabolites have been implicated in the pathogenesis of chronic neurodegenerative and vascular diseases, the relationship of inherited variants in the mitochondrial genome and mt haplogroup subtypes with advanced AMD has not been reported in large prospective cohorts.Methodology/Prinicipal Findings
We examined the relationship of inherited mtDNA variants with advanced AMD in 1168 people using a three-stage design on samples from 12-year and 10-year prospective studies on the natural history of age-related eye disease. In Stage I we resequenced the entire genome in 99 elderly AMD-free controls and 215 people with advanced AMD from the 12-year study. A consistent association with AMD in 14 of 17 SNPs characterizing the mtDNA T haplogroup emerged. Further analysis revealed these associations were driven entirely by the T2 haplogroup, and characterized by two variants in Complex I genes (A11812G of MT-ND4 and A14233G of MT-ND6). We genotyped T haplogroups in an independent sample of 490 cases and 61 controls from the same study (Stage II) and in 56 cases and 246 controls from the 10-year study (Stage III). People in the T2 haplogroup were approximately 2.5 times more likely to have advanced AMD than their peers (odds ratio [OR] = 2.54, 95%CI 1.36–4.80, P≤0.004) after considering the totality of evidence. Findings persisted after considering the impact of AMD-associated variants A69S and Y402H (OR = 5.19, 95%CI 1.19–22.69, P≤0.029).Conclusion
Loci defining the mtDNA T2 haplogroup and Complex I are reasonable targets for novel functional analyses and therapeutic research in AMD. 相似文献100.
Wing Leung Geoffrey Neale Fred Behm Rekha Iyengar David Finkelstein Michael B. Kastan Ching-Hon Pui 《Cancer epidemiology》2010,34(3):303-308
Background: Survivors of childhood acute lymphoblastic leukemia (ALL) are at an increased risk of developing secondary malignant neoplasms. Radiation and chemotherapy can cause mutations and cytogenetic abnormalities and induce genomic instability. Host immunity and appropriate DNA damage responses are critical inhibitors of carcinogenesis. Therefore, we sought to determine the long-term effects of ALL treatment on immune function and response to DNA damage. Methods: Comparative studies on 14 survivors in first complete remission and 16 siblings were conducted. Results: In comparison to siblings on the cells that were involved in adaptive immunity, the patients had either higher numbers (CD19+ B cells and CD4+CD25+ T regulatory cells) or similar numbers (αβT cells and CD45RO+/RA? memory T cells) in the blood. In contrast, patients had lower numbers of all lymphocyte subsets involved in innate immunity (γδT cells and all NK subsets, including KIR2DL1+ cells, KIR2DL2/L3+ cells, and CD16+ cells), and lower natural cytotoxicity against K562 leukemia cells. Thymopoiesis was lower in patients, as demonstrated by less CD45RO?/RA+ naïve T cell and less SjTREC levels in the blood, whereas the Vβ spectratype complexity score was similar. Array of gene expression response to low-dose radiation showed that about 70% of the probesets had a reduced response in patients. One of these genes, SCHIP-1, was also among the top-ranked single nucleotide polymorphisms (SNPs) during the whole-genome scanning by SNP microarray analysis. Conclusion: ALL survivors were deficient in innate immunity, thymopoiesis, and DNA damage responses to radiation. These defects may contribute to their increased likelihood of second malignancy. 相似文献