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991.
In this paper, an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo bilobaL. leaves from different ages and sources, including six flavonol glycosides, five terpene lactones and nine organic acids. Using statistics method and establishing relevant mathematics models, the measured data has proceeded correlation analysis, principal component analysis, and regression statistics and the results showed generalityand specific characteristics. We defined p-hydroxybenzoicacid, catechinic, KRcG and ginkgolide A as characteristic indexes representing commonnessand specialityof Ginkgo biloba L. leaf. The four characteristic indexes can reflect the quality of Ginkgo biloba L. leaf, and the internal relations between them are significant.The contents of other compounds could define the quantity relation with characteristic markers. It simplified the approach of quality control, and provided a basis for quality control of Ginkgo biloba L. 相似文献
992.
Jingwei Wei Hanyu Jiang Dongsheng Gu Meng Niu Fangfang Fu Yuqi Han Bin Song Jie Tian 《Liver international》2020,40(9):2050-2063
Liver diseases, a wide spectrum of pathologies from inflammation to neoplasm, have become an increasingly significant health problem worldwide. Noninvasive imaging plays a critical role in the clinical workflow of liver diseases, but conventional imaging assessment may provide limited information. Accurate detection, characterization and monitoring remain challenging. With progress in quantitative imaging analysis techniques, radiomics emerged as an efficient tool that shows promise to aid in personalized diagnosis and treatment decision‐making. Radiomics could reflect the heterogeneity of liver lesions via extracting high‐throughput and high‐dimensional features from multi‐modality imaging. Machine learning algorithms are then used to construct clinical target‐oriented imaging biomarkers to assist disease management. Here, we review the methodological process in liver disease radiomics studies in a stepwise fashion from data acquisition and curation, region of interest segmentation, liver‐specific feature extraction, to task‐oriented modelling. Furthermore, the applications of radiomics in liver diseases are outlined in aspects of diagnosis and staging, evaluation of liver tumour biological behaviours, and prognosis according to different disease type. Finally, we discuss the current limitations of radiomics in liver disease studies and explore its future opportunities. 相似文献
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Fu‐Chun Zhou MD PhD Yu‐Tao Xiang MD PhD Chuan‐Yue Wang MD PhD Faith Dickerson PhD Julie Kreyenbuhl PharmD PhD Gabor S. Ungvari MD PhD Raymond W. C. Au PhD Jing‐Jing Zhou MPhil Yan Zhou BA David Shum PhD David Man PhD Kelly Y. C. Lai MRCPsy Wai‐Kwong Tang MRCPsy Xin Yu MD Helen F. K. Chiu FRCPsy 《Perspectives in psychiatric care》2014,50(2):102-110
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998.
Marcos Fu HC Powers TR Stocker R 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(13):4780-4785
The motility of organisms is often directed in response to environmental stimuli. Rheotaxis is the directed movement resulting from fluid velocity gradients, long studied in fish, aquatic invertebrates, and spermatozoa. Using carefully controlled microfluidic flows, we show that rheotaxis also occurs in bacteria. Excellent quantitative agreement between experiments with Bacillus subtilis and a mathematical model reveals that bacterial rheotaxis is a purely physical phenomenon, in contrast to fish rheotaxis but in the same way as sperm rheotaxis. This previously unrecognized bacterial taxis results from a subtle interplay between velocity gradients and the helical shape of flagella, which together generate a torque that alters a bacterium's swimming direction. Because this torque is independent of the presence of a nearby surface, bacterial rheotaxis is not limited to the immediate neighborhood of liquid-solid interfaces, but also takes place in the bulk fluid. We predict that rheotaxis occurs in a wide range of bacterial habitats, from the natural environment to the human body, and can interfere with chemotaxis, suggesting that the fitness benefit conferred by bacterial motility may be sharply reduced in some hydrodynamic conditions. 相似文献
999.
Harman MW Dunham-Ems SM Caimano MJ Belperron AA Bockenstedt LK Fu HC Radolf JD Wolgemuth CW 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(8):3059-3064
The Lyme disease spirochete Borrelia burgdorferi exists in nature in an enzootic cycle that involves the arthropod vector Ixodes scapularis and mammalian reservoirs. To disseminate within and between these hosts, spirochetes must migrate through complex, polymeric environments such as the basement membrane of the tick midgut and the dermis of the mammal. To date, most research on the motility of B. burgdorferi has been done in media that do not resemble the tissue milieus that B. burgdorferi encounter in vivo. Here we show that the motility of Borrelia in gelatin matrices in vitro resembles the pathogen's movements in the chronically infected mouse dermis imaged by intravital microscopy. More specifically, B. burgdorferi motility in mouse dermis and gelatin is heterogeneous, with the bacteria transitioning between at least three different motility states that depend on transient adhesions to the matrix. We also show that B. burgdorferi is able to penetrate matrices with pore sizes much smaller than the diameter of the bacterium. We find a complex relationship between the swimming behavior of B. burgdorferi and the rheological properties of the gelatin, which cannot be accounted for by recent theoretical predictions for microorganism swimming in gels. Our results also emphasize the importance of considering borrelial adhesion as a dynamic rather than a static process. 相似文献
1000.
Agirrezabala X Liao HY Schreiner E Fu J Ortiz-Meoz RF Schulten K Green R Frank J 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(16):6094-6099
Cryo-EM analysis of a wild-type Escherichia coli pretranslocational sample has revealed the presence of previously unseen intermediate substates of the bacterial ribosome during the first phase of translocation, characterized by intermediate intersubunit rotations, L1 stalk positions, and tRNA configurations. Furthermore, we describe the domain rearrangements in quantitative terms, which has allowed us to characterize the processivity and coordination of the conformational reorganization of the ribosome, along with the associated changes in tRNA ribosome-binding configuration. The results are consistent with the view of the ribosome as a molecular machine employing Brownian motion to reach a functionally productive state via a series of substates with incremental changes in conformation. 相似文献