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71.
The interpretation of chronic bioassay tests for carcinogenicity requires that the data be appropriately recorded. A "case history" for each animal links the pathology data for each organ of each animal to the length of its life. This information can be used in interpretation of the tumor incidences in light of the survival information. The role of historical controls was discussed, and the use of significance tests in a multidisciplinary approach to the assessment of the pattern of tumor response was suggested. Multiple comparison methods valid for the interpretation of continuous (or measurement) data do not apply to the discrete data analyses used in these studies. The ideas and methods of these studies were applied to an animal study of chloroform. 相似文献
72.
73.
74.
Endogenous sex hormones and prostate cancer risk: a case-control study nested within the Carotene and Retinol Efficacy Trial. 总被引:5,自引:0,他引:5
Chu Chen Noel S Weiss Frank Z Stanczyk S Kay Lewis Dante DiTommaso Ruth Etzioni Matt J Barnett Gary E Goodman 《Cancer epidemiology, biomarkers & prevention》2003,12(12):1410-1416
To examine whether endogenous androgens influence the occurrence of prostate cancer, we conducted a nested case-control study among participants enrolled in the Carotene and Retinol Efficacy Trial. We analyzed serum samples of 300 cases diagnosed between 1987 and 1998, and 300 matched controls. Higher concentrations of testosterone (T) were not associated with increased prostate cancer risk. Relative to men with levels in the lowest fourth of the distribution, men in the upper fourth of total T had a risk of 0.82 [95% confidence interval (CI), 0.52-1.29]. The corresponding relative risks for free T (0.72; 95% CI, 0.45-1.14), percentage of free T (0.74; 95% CI, 0.46-1.19), and total T:sex hormone binding globulin ratio (0.52; 95% CI, 0.32-0.83) similarly were not elevated. Higher concentrations of androstenedione, dehydroepiandrosterone sulfate, and 3 alpha-androstanediol glucuronide were weakly associated with risk. Relative risks associated with being in the highest fourth for androstenedione, dehydroepiandrosterone sulfate, and 3 alpha-androstanediol glucuronide were 1.20 (95% CI, 0.76-1.89), 1.38 (95% CI, 0.86-2.21), and 1.27 (95% CI, 0.80-2.00), respectively. Men in the upper fourth of total estradiol (E2), free E2 and percentage of free E2 had relative risks of 0.71 (95% CI, 0.42-1.13), 0.52 (95% CI, 0.33-0.82), and 0.65 (95% CI, 0.40-1.05), respectively. The inverse association between E2 and prostate cancer risk was largely restricted to men with blood collection within 3 years of diagnosis. Our results add to the evidence that serum testosterone is unrelated to prostate cancer incidence. The suggestions that intraprostatic androgen activity may increase risk and that serum estrogens may decrease risk, warrant additional study. 相似文献
75.
中药脑肺康对地鼠实验性肺气肿及肺动脉高压的防治作用 总被引:2,自引:0,他引:2
目的 观察中药肺康对缺氧性肺动脉高压和肺气肿的防治效果并探讨其作用机制。方法 以弹性蛋白酶溶液滴注入金黄地鼠气管内,正常饲养30d后,常压下缺氧15d,分别设立中药脑肺康预防组、治疗组、肺气肿+缺氧组及正常对照组。于处死动物前,测量平均肺动脉压,取静脉血进行循环内皮细胞计数;处死后测量右心肥大指数,光镜下计数左侧肺支气管肺泡灌洗液内细胞总数,对右侧肺进行光镜图像分析。结果 中药脑肺康预防组和治疗3 相似文献
76.
采用数字减影血管造影技术超选择性动脉栓塞治愈2例血管搏动怀耳鸣,并就发病原因、机理、治疗措施、临床特征进行讨论。 相似文献
77.
The effect of Rhodiola capsules on oxygen consumption of myocardium and coronary artery blood flow in dogs] 总被引:1,自引:0,他引:1
Z Zhang J Liu X Shang J Yang J Chu Z Wang Z Yao H Ma Q Li Y Wang 《中国中药杂志》1998,23(2):104-6, inside back cover
It has been proved that Rhodiola Capsules can obviously decrease the oxygen consumption of myocardium and oxygen consumption index in anesthetic dogs, decrease the coronary artery resistance, but have no marked effect on the coronary artery blood flow. The Capsules also have the function of decreasing blood presure and slowing heart rate. 相似文献
78.
Karalis T Gupta L Chu M Campbell BA Capra MF Maywood PA 《The Medical journal of Australia》2000,172(4):160-162
Between July 1997 and August 1998 we investigated three clusters (26 cases) of ciguatera poisoning in the inner Sydney area. Tropical reef fish were implicated in each cluster. Most of those affected had musculoskeletal, neurological and gastrointestinal symptoms. The clusters raise questions about the need for rapid diagnosis and enhanced surveillance mechanisms, the regulation of fish supply, and the lack of testing facilities for ciguatera toxin. 相似文献
79.
PURPOSE: To study the incidence of adverse events after i.v. injection of MR contrast agents in a Chinese population. A comparison was made between an ionic contrast agent (dimeglumine gadopentetate, Magnevist) and a non-ionic contrast agent (gadodiamide, Omniscan). MATERIAL AND METHODS: During a 24-month period, 2,049 Chinese patients who randomly received an i.v. bolus injection of either Magnevist or Omniscan were investigated. All patients were questioned for the presence of any generalized or localized adverse reaction on the following day after the MR examination according to a standardized questionnaire. RESULTS: Three hundred and nine out of 2,049 patients (15%) reported an adverse event. There was a higher incidence of adverse events in patients receiving Magnevist as compared to those receiving Omniscan injection. All reported adverse events were clinically mild and required neither treatment nor hospitalization. CONCLUSION: There was a higher incidence of adverse reaction in patients receiving Magnevist than in those receiving Omniscan. 相似文献
80.
In the neocortex, fast excitatory synaptic transmission can typically be blocked by using excitatory amino acid (EAA) receptor antagonists. In recordings from layer II/III neocortical pyramidal neurons, we observed an evoked excitatory postsynaptic potential (EPSP) or current (EPSC) in the presence of EAA receptor antagonists (40-100 microM D-APV+20 microM CNQX, or 5 mM kynurenic acid) plus the GABA(A)-receptor antagonist bicuculline (BIC, 20 microM). This EAA-antagonist resistant EPSC was observed in about 70% of neurons tested. It had a duration of approximately 20 ms and an amplitude of 61.5+/-6.8 pA at -70 mV (n=35). The EAA-antagonist resistant EPSC current-voltage relation was linear and reversed near 0 mV (n=23). The nonselective nicotinic acetylcholine receptor (nAChR) antagonists dihydro-beta-erythroidine (DH beta E, 100 microM) or mecamylamine (50 microM) reduced EPSC amplitudes by 42 (n=20) and 33% (n=9), respectively. EPSC kinetics were not significantly changed by either antagonist. Bath application of 10 microM neostigmine, a potent acetylcholinesterase inhibitor, prolonged the EPSC decay time. EAA-antagonist resistant EPSCs were observed in the presence of antagonists of metabotropic glutamate, serotonergic (5-HT(3)) and purinergic (P2) receptors. The EAA-antagonist resistant EPSC appears to be due in part to activation of postsynaptic nAChRs. These results suggest the existence of functional synaptic nAChRs on pyramidal neurons in rat neocortex. 相似文献