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91.
92.
Interinstitutional variations of sensitometric curves of radiographic dosimetric films 总被引:1,自引:0,他引:1
Bos LJ Danciu C Cheng CW Brugmans MJ van der Horst A Minken A Mijnheer BJ 《Medical physics》2002,29(8):1772-1780
Depth and field size dependence of the sensitometric curves of radiographic films have been studied by various groups. Limited information is, however, available on the magnitude of the variations in sensitometric curves applied in clinical practice in different institutions. In this study we assessed in a systematic way the effect of the various parameters influencing the shape of the sensitometric curve: batch composition, irradiation conditions, film processing, and film scanning. Two types of film, Kodak X-Omat V and CEA TVS, were irradiated, processed, and analyzed in three different institutions. The interinstitutional variation of the sensitometric curves, expressed as the OD variation at 50 cGy, can be up to 32% and is mainly caused by differences in film processing and to a lesser degree to differences in batch composition, film scanning, and irradiation conditions. For the Kodak films, the average OD difference at 50 cGy between the three institutions is 17% as a result of differences in batch composition and 25% due to differences in processing conditions. For the CEA films these data are 6% and 24%, respectively. The long-term variation of the sensitometric curves of KODAK films in one institution was smaller than the differences in batch composition between the three institutions. The sensitometric curves of CEA films showed in one institution a large variation with time; the shape gradually varied from sigmoidal to quasilinear. By using relative OD values rather than absolute OD values, variations in sensitometric curves of KODAK films can be reduced to 2%. Consequently, one sensitometric curve is sufficient to derive relative dose values. If processing conditions are well controlled, it might therefore be advantageous to determine the absolute OD only at one or two dose values, in combination with a "universal" relative sensitometric curve. 相似文献
93.
Tlili A Charfedine I Lahmar I Benzina Z Mohamed BA Weil D Idriss N Drira M Masmoudi S Ayadi H 《Human mutation》2005,25(5):503
Approximately 80% of hereditary hearing loss is non-syndromic. Non-syndromic deafness is the most genetically heterogeneous trait. The most common and severe form of hereditary hearing impairment is autosomal recessive non-syndromic hearing loss (ARNSHL), accounting for approximately 80% of cases of genetic deafness. To date, 22 genes implicated in ARNSHL have been identified. Recently a gene, DFNB31/WHRN, which encodes a putative PDZ scaffold protein called whirlin, was found to be responsible for the ARNSHL DFNB31. We found evidence for linkage to the DFNB31locus in a consanguineous Tunisian family segregating congenital profound ARNSHL. Mutation screening of DFNB31/WHRNrevealed four nonpathogenic sequence variants and a novel frameshift mutation [c.2423delG] + [c.2423delG] that changed the reading frame and induced a novel stop codon at amino acid 818 ([p.Gly808AspfsX11] + [p.Gly808AspfsX11]). To determine the contribution of the DFNB31locus in the childhood deafness, we performed linkage analysis in 62 unrelated informative families affected with ARNSHL. No linkage was found to this locus. From this study, we concluded that DFNB31/WHRN is most likely to be a rare cause of ARNSHL in the Tunisian population. 相似文献
94.
Goldberg I Gilburd B Kravitz MS Kivity S Chaim BB Klein T Schiffenbauer Y Trubniykovr E Brenner S Shoenfeld Y 《Clinical & developmental immunology》2005,12(1):85-90
Background: There are several mechanisms to describe allergic drug
reactions yet the methods to diagnose them are limited.
Objective: To compare several conventional clinical and laboratory
methods to diagnose skin reactions to drugs
to a new method of diagnosing drug reactions by the CellScan system.
Methods: The study entailed 21 patients who were diagnosed as
suffering from drug eruptions, and 105 healthy controls with no history of drug
allergy. The drugs were classified into two groups according to suspicion of
causing drug allergy: high and low. Most of the patients were on more than
one drug, leading to 41 patient-drug interactions (assays). Histamine
releasing test (HRT), interferon (INF)-γ releasing test and CellScan
examination were performed on lymphocytes of the patients and controls.
Results: The HRT was interpreted as positive in 9 out of 18 (50%)
patients and in 13 out of 35 (37%) assays. Based on the INF-γ releasing test,
positive results were observed in 16 out of 21 (76%) patients and in 24 out of 41
(59%) assays. In the CellScan test (CST), positive results were observed in 17
out of 21 (81%) patients and in 29 out of 41 (71%) assays. The rate of identifying
the drug for eruption in the high suspicion level drugs was 9 out of 22 (41%)
assays in the HRT, 20 out of 24 (83%) assays in the INF-γ releasing test, and 21
out of 24 (87%) studies with the CellScan method. The rate of determining of
the drug that caused the eruption in the low suspicion level drugs was 4 out of
13 (31%) in the HRT, 4 out of 17 (24%) assays in the INF-γ releasing test, and 8
out of 17 (47%) analyses in the CST. When examined
in the CellScan, 99 out of 105 (94%) controls were interpreted as negative.
Conclusion: This preliminary study indicates that the CellScan seems to
be an easy and promising method for the detection of drugs responsible for
adverse skin reactions. In contrast to the HRT and to the Interferon-γ secretion
test, the CellScan method is characterized by its ability to track and monitor
the reaction of individual cells. By measuring the kinetic parameters of selected
cells before and after adding the suspected drug, we were able to identify
the culprit drug. The CellScan method had the highest sensitivity, and the
interferon-γ secretion test had the highest specificity for detection of the culprit
drug. In contrast, the analysis of 105
normal control sera disclosed a high specificity of 94% for the CellScan method. 相似文献
95.
96.
Weimin Sun Ben Anderson Joy Redman Aubrey Milunsky Arlene Buller Matthew J McGinniss Franklin Quan Arturo Anguiano Stephen Huang Feras Hantash Charles Strom 《Genetics in medicine》2006,8(6):339-345
PURPOSE: The study's purpose was to understand the molecular basis for different clinical phenotypes of the 5T variant, a tract of 5 thymidines in intron 8 of the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which disrupts processing of CFTR mRNA and reduces synthesis from the corresponding CFTR alleles. METHOD: We analyzed the polymorphic TG dinucleotide repeat adjacent to the 5T variant in intron 8 and the codon 470 in exon 10. Patients selected for this study were positive for both the 5T variant and the major cystic fibrosis mutation, Delta F508. Almost all Delta F508 mutation alleles occur in a 10TG-9T-470M haplotype. Therefore, it is possible to determine the haplotype of the 5T variant in trans. RESULTS: Of the 74 samples analyzed, 41 (55%) were 11TG-5T-470M, 31 (42%) were 12TG-5T-470V, and 2 (3%) were 13TG-5T-470M. Of the 49 cases for which we had clinical information, 17.6% of females (6/34) and 66.7% of males (10/15) showed symptoms resembling atypical cystic fibrosis. The haplotype with the highest penetrance in females (42% or 5/12) and more than 80% (5/6) in males is 12TG-5T-470V. We also evaluated 12 males affected with congenital bilateral absence of vas deferens and positive for the 5T variant; 10 of 12 had the 12TG-5T-470V haplotype. CONCLUSION: Overall, the 5T variant has a milder clinical consequence than previously estimated in females. The clinical presentations of the 5T variant are associated with the 5T-12TG-470M haplotype. 相似文献
97.
Illigens BM Yamada A Fedoseyeva EV Anosova N Boisgerault F Valujskikh A Heeger PS Sayegh MH Boehm B Benichou G 《Human immunology》2002,63(10):912-925
In this study, we measured direct and indirect T-cell alloresponses mediated by CD4(+) and CD8(+) T cells in three mouse transplantation models: skin, cornea, and retina. We show that the contribution of direct and indirect antigen recognition pathways to the alloresponse to fully allogeneic grafts varies depending upon the nature of the tissue/organ transplanted. The implications of this finding for understanding the cellular mechanisms by which rejection is mediated in different transplant models are discussed. 相似文献
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