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91.
G. J. Gram A. Hemming A. Bolmstedt B. Jansson S. Olofsson L. Åkerblom J. O. Nielsen J. E. S. Hansen 《Archives of virology》1994,139(3-4):253-261
Summary Glycosylation is necessary for HIV-1 gp120 to attain a functional conformation, and individual N-linked glycans of gp120 are important, but not essential, for replication of HIV-1 in cell culture. We have constructed a mutant HIV-1 infectious clone lacking a signal for N-linked glycosylation in the V1-loop of HIV-1 gp120. Lack of an N-linked glycan was verified by a mobility enhancement of mutant gp120 in SDS-gel electrophoresis. The mutated virus showed no differences in either gp120 content per infectious unit or infectivity, indicating that the N-linked glycan was neither essential nor affecting viral infectivity in cell culture. We found that the mutated virus lacking an N-linked glycan in the V1-loop of gp120 was more resistant to neutralization by monoclonal antibodies to the V3-loop and neutralization by soluble recombinant CD4 (sCD4). Both viruses were equally well neutralized by ConA and a conformation dependent human antibody IAM-2G12. This suggests that the N-linked glycan in the V1-loop modulates the three-dimensional conformation of gp120, without changing the overall functional integrity of the molecule. 相似文献
92.
M Tomioka R H Stead L Nielsen M D Coughlin J Bienenstock 《The Journal of allergy and clinical immunology》1988,82(4):599-607
The effects of 2.5S nerve growth factor (NGF) and epidermal growth factor (EGF), isolated from mouse submaxillary glands, on histamine release from rat peritoneal mast cells (PMCs) were studied. In the absence of phosphatidylserine, NGF (1 ng/ml to 1 microgram/ml) did not cause histamine release from PMCs isolated from normal rats and those infected with the nematode Nippostrongylus brasiliensis. However, when PMCs (greater than 97% pure) were preincubated with NGF and then challenged with worm antigen (Ag), there was a marked enhancement of histamine release (approximately twofold with a maximum effect at 10 ng/ml of NGF [3.8 X 10(-10) mol/L]) compared with the release induced by Ag alone. EGF (1 ng/ml to 1 microgram/ml) neither produced histamine release from PMCs in the presence of phosphatidylserine nor enhanced Ag-induced histamine release. This suggests that NGF acts directly on PMCs by activation of cell-surface receptors. The early kinetics of Ag-induced histamine release were altered by NGF that increased the initial rate at 15 seconds but did not prolong the overall duration of histamine release. Simultaneous addition of Ag and NGF did not cause enhanced histamine release; thus, some preincubation time with NGF (5 minutes or less) was required for the activation of PMCs. Moreover, after PMCs were activated by NGF, that state persisted for 1 hour, even when unbound NGF was removed by washing, and thereafter subsided gradually. Further studies revealed that NGF enhanced histamine release induced by concanavalin A, compound 48/80, and ionophore A23187. These results suggest that NGF might be an important molecule in inflammatory responses through the regulation of mediator release from mast cells. 相似文献
93.
94.
A method of wide applicability is described for the study of serological changes in response to particulate antigens. The practical and theoretical aspects of the method have been explored in estimation of antibody to Micropolyspora faeni in human cases of farmer's lung syndrome. This method, using a radiolabelled antiglobulin to detect cell-bound antibody, was found to be of high sensitivity and reproducibility. Antibody has been estimated in micrograms per millilitre of serum by correlation with the results of quantitative agglutination test. 相似文献
95.
96.
Jacobsen HP Herskind AM Nielsen BW Husby S 《The Journal of allergy and clinical immunology》2001,107(4):659-663
BACKGROUND: IgE is a major determinant of allergic disease. Twin analysis of serum levels of IgE has been carried out previously in children and adults with heritability estimates of 30% to 70% on the basis of ANOVA. OBJECTIVE: This study included the analysis of serum IgE in a population of 126 twins, 27 monozygotic pairs and 36 dizygotic pairs, studied at birth (cord blood [CB] IgE) and consecutively at the age of 6 to 9 years of age (serum IgE). METHODS: IgE was determined by means of RIA. ANOVA, correlation analysis, and structural equation modeling by maximal likelihood analysis was used for genetic analysis. RESULTS: Structural equation modeling by maximal likelihood analysis showed the best-fitting model to be the AE model (A for additive genetic variance and E for environmental variance) both at birth and later in childhood. The estimated heritability was 0.92 (95% CI, 0.84-0.95) for CB IgE and 0.78 (95% CI, 0.60-0.87) for serum IgE. The correlation between CB IgE and serum IgE was 0.04. CONCLUSIONS: The study demonstrated a higher genetic dependency of serum IgE than previously recognized. The low correlation between the IgE levels at birth and later in childhood suggested that different effector mechanisms may be operating at different ages. 相似文献
97.
Some new, simple and efficient stereological methods and their use in pathological research and diagnosis 总被引:44,自引:0,他引:44
H J Gundersen T F Bendtsen L Korbo N Marcussen A M?ller K Nielsen J R Nyengaard B Pakkenberg F B S?rensen A Vesterby 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》1988,96(5):379-394
Stereology is a set of simple and efficient methods for quantitation of three-dimensional microscopic structures which is specifically tuned to provide reliable data from sections. Within the last few years, a number of new methods has been developed which are of special interest to pathologists. Methods for estimating the volume, surface area and length of any structure are described in this review. The principles on which stereology is based and the necessary sampling procedures are described and illustrated with examples. The necessary equipment, the measurements, and the calculations are invariably simple and easy. 相似文献
98.
We have studied the reproducibility of a bronchial leukotriene (LT) provocation test in asthmatics, and the effect of prior treatment with an oral leukotriene D4/E4 antagonist (SR 2640) on LTD4-induced bronchoconstriction in nine asthmatics in a double-blind placebo-controlled randomized cross-over trial. The reproducibility of the bronchial leukotriene provocation test was high. For a specific patient, the replication variance is 0.2303, and the standard deviation is thus 0.4799, corresponding to 48%, i.e. one halving of the dose or half doubling of the dose. SR 2640 antagonised LTD4 induced bronchoconstriction causing a mean shift of 48% to the right of the dose-response curve as compared with placebo (95% confidence interval being 11-137%). This study demonstrates that bronchial LTD4 provocation test is a safe and reproducible method in asthmatics, and that the method can be used to detect LT-antagonism; furthermore that SR 2640 is a weak LTD4-antagonist in asthmatics. 相似文献
99.
Afzelius P Nielsen JO 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2000,108(1):74-78
HIV infection is characterized by the loss of CD4+ T cells as well as the loss of T-cell function, leading to severe immunodeficiency. The proliferative capacity of T cells measured in vitro as responses to antigens and mitogens is severely reduced during HIV infection. An increased level of the intracellular second messenger adenosine 3',5'-cyclic monophosphate (cAMP) has been shown to cause impaired proliferative capacity of peripheral blood mononuclear cells (PBMC) from HIV-infected individuals in vitro. Sumatriptan, a 5HT1d receptor agonist, inhibits the activity of adenylyl cyclases, the enzymes responsible for regulation of the intracellular levels of cAMP. In a preliminary study sumatriptan increased the proliferative responses of PBMC to a polyclonal activator in vitro in 9 of 10 HIV-seropositive individuals (p=0.007), and in 7 of 9 healthy blood donors (p=0.05). This was probably due to a decrease in the intracellular level of cyclic AMP. 相似文献
100.
C Nielsen C M Nielsen J L Petersen P C G?tzsche C Pedersen M Arendrup B F Vestergaard 《Journal of virological methods》1991,35(1):15-25
Isolation of HIV from cultures of CD4+ lymphocytes purified from peripheral blood by indirect panning was optimized and evaluated. Infectious HIV was isolated by single isolation attempts in 98% of 102 HIV-antibody-positive patients (55 had AIDS or ARC and 47 were clinically healthy). The average culture time required for positive cultures was largely independent of the CD4 count of the patients and 87% of the positive isolation cultures from both groups of patients became positive within 14 days of culture. An evaluation of the possible influence of media additives on propagation of HIV showed that: amphotericin-B had a suppressive effect on HIV replication at concentrations recommended for anti-fungal activity; recombinant and human interleukin-2 were equally suitable for both isolation cultures and for propagation of HIV, and polybrene, at a concentration of 2 micrograms/ml in the culture medium had a beneficial effect. 相似文献