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71.
Chronic hepatitis C virus (HCV) infection is one of the major causes for development of liver cirrhosis and end-stage liver disease. This article reviews two contrasting models of HCV pathogenesis, discusses the merits of each, and presents a rationale for combining the two models into one. Any successful model of HCV pathogenesis must explain how the characteristic features of cirrhosis and end-stage liver disease arise. These features include the loss of hepatocyte function (low serum albumin and reduced clotting ability); the presence of regenerative nodules; and the deposition of excessive extracellular matrix material, especially collagen (fibrosis), which is associated with the transformation of the liver sinusoids to capillary-like structures leading to portal hypertension. A successful model should explain several observations about the rate of disease progression. HCV is characterized by slow progression of fibrogenesis and, importantly, cirrhosis seems to develop only after a long latency (and only in a subset of patients). Among the prognostic factors of disease progression, the age at infection with the HCV virus and the presence of fibrosis appear to be highly relevant in predicting the development of progressive fibrosis. Traditional models of HCV pathogenesis propose that fibrogenesis is the predominant process. Fibrogenesis is induced by activation of fibrogenic cells, such as stellate cells, which results in excessive collagen deposition. By altering the normal architecture and vasculature, the collagen bands finally lead to cirrhosis and loss of organ function. Activation of stellate cells is induced by inflammation, cytokine signaling, and possibly by hepatocyte apoptosis. The telomere model of HCV pathogenesis suggests that hepatocyte damage plays an essential role in the development of cirrhosis. According to this model, hepatocyte damage leads to increased cell turnover, and to the accelerated shortening of hepatocyte telomeres. Critical telomere shortening leads to hepatocyte senescence, loss of hepatocyte function, exhaustion of hepatocellular regeneration, and to a greatly enhanced fibrotic response to injury. This review summarizes both models and presents evidence that these models are not mutually exclusive but rather can be merged into a comprehensive pathogenesis model that outlines the pathway of HCV-induced cirrhosis.  相似文献   
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Peptide-mediated broad-spectrum plant resistance to tospoviruses   总被引:6,自引:0,他引:6       下载免费PDF全文
Plant viruses have a significant impact on agronomic losses worldwide. A new strategy for engineering virus-resistant plants by transgenic expression of a dominant interfering peptide is presented here. This peptide of 29 aa strongly interacts with the nucleocapsid proteins (N) of different tospoviruses. Transgenic Nicotiana benthamiana lines expressing the peptide fused to a carrier protein were challenged with five different tospoviruses that have a nucleocapsid protein interacting with the peptide. In the transgenic plants, strong resistance to tomato spotted wilt virus, tomato chlorotic spot virus, groundnut ring spot virus, and chrysanthemum stem necrosis virus was observed. This therefore demonstrates the feasibility of using peptide "aptamers" as an in vivo tool to control viral infection in higher plants.  相似文献   
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Ohne ZusammenfassungAuszugsweise vorgetragen auf der 44. Tagung der Deutschen Gesellschaft für Pathologie in Münster, Mai 1961 und auf der International Conference on Morphological Precursors of Cancer in Perugia, Juni 1961.  相似文献   
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Results of a high-resolution genome screen of 437 Alzheimer's disease families   总被引:13,自引:0,他引:13  
Alzheimer's disease (AD) is a devastating neurodegenerative disorder of late life with complex inheritance. Mutations in three known genes lead to the rare early-onset autosomal dominant form of AD, while a common polymorphism (epsilon 4) in the gene encoding apolipoprotein E (APOE ) is a risk factor for more typical late-onset (>60 years) AD. A recent study concluded that there are up to four additional genes with an equal or greater contribution to the disease. We performed a 9 cM genome screen of 437 families with AD, the full National Institute of Mental Health (NIMH) sample, which has been carefully ascertained, evaluated and followed by our group over the last decade. Performing standard parametric and non-parametric linkage analyses, we observed a 'highly significant' linkage peak by Lander and Kruglyak criteria on chromosome 19q13, which probably represents APOE. Twelve additional locations-on 1q23, 3p26, 4q32, 5p14, 6p21, 6q27, 9q22, 10q24, 11q25, 14q22, 15q26 and 21q22-met criteria for 'suggestive' linkage [i.e. two-point lod score (TLS) >/=1.9 and/or multipoint lod score (MLS) >/=2.2] in at least one of our analyses. Although some of these will surely prove to be false positives, these linkage signals should provide a valuable framework for future studies aimed at identifying additional susceptibility genes for late-onset AD.  相似文献   
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Parkinson disease (PD) is the second most common neurodegenerative disorder. We studied 754 affected individuals, comprising 425 sibling pairs, to identify PD susceptibility genes. Screening of the parkin gene was performed in a subset of the sample having earlier age of PD onset or a positive LOD score with a marker in the parkin gene. All subjects were evaluated using a rigorous neurological assessment. Two diagnostic models were considered for genome-wide, non-parametric linkage analyses. Model I included only those individuals with a more stringent diagnosis of verified PD (216 sibling pairs) and resulted in a maximum LOD score of 3.4 on chromosome 2. Model II included all affected individuals (425 sibling pairs) and yielded a LOD score of 3.1 on the X chromosome. Our large sample was then employed to test for gene-by-gene (epistatic) interactions. A genome screen using the 23 families with PD patients having a mutation in only one allele of the parkin gene detected evidence of linkage to chromosome 10 (LOD=2.3). The 85 families with a very strong family history of PD were employed in a genome screen and, in addition to strong evidence of linkage to chromosome 2 (LOD=4.9), also produced a LOD of 2.4 on chromosome 14. A genome screen performed in the 277 families without a strong family history of PD detected linkage to chromosomes 10 (LOD=2.4) and X (LOD=3.2). These findings demonstrate consistent evidence of linkage to chromosomes 2 and X and also support the hypothesis that gene-by-gene interactions are important in PD susceptibility.  相似文献   
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Infiltrating lobular breast cancer (ILBC) is a clinically and biologically distinct tumour entity defined by a characteristic linear cord invasion pattern and inactivation of the CDH1 tumour suppressor gene encoding for E‐cadherin. ILBCs also lack β‐catenin expression and show aberrant cytoplasmic localization of the E‐cadherin binding protein p120‐catenin. The lack of a well‐characterized ILBC cell line has hampered the functional characterization of ILBC cells in vitro. We report the establishment of a permanent ILBC cell line, named IPH‐926, which was derived from a patient with metastatic ILBC. The DNA fingerprint of IPH‐926 verified genetic identity with the patient and had no match among the human cell line collections of several international biological resource banks. IPH‐926 expressed various epithelial cell markers but lacked expression of E‐cadherin due to a previously unreported, homozygous CDH1 241ins4 frameshift mutation. Detection of the same CDH1 241ins4 mutation in archival tumour tissue of the corresponding primary ILBC proved the clonal origin of IPH‐926 from this particular tumour. IPH‐926 also lacked β‐catenin expression and showed aberrant cytoplasmic localization of p120‐catenin. Array‐CGH analysis of IPH‐926 revealed a profile of genomic imbalances that included many distinct alterations previously observed in primary ILBCs. Spectral karyotyping of IPH‐926 showed a hyperdiploid chromosome complement and numerous clonal, structural aberrations. IPH‐926 cells were anti‐cancer drug‐resistant, clonogenic in soft agar, and tumourigenic in SCID mice. In xenograft tumours, IPH‐926 cells recapitulated the linear cord invasion pattern that defines ILBCs. In summary, IPH‐926 significantly extends the biological spectrum of the established breast cancer cell lines and will facilitate functional analyses of genuine human ILBC cells in vitro and in vivo. Copyright © 2008 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.  相似文献   
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