首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   21204篇
  免费   1415篇
  国内免费   236篇
耳鼻咽喉   354篇
儿科学   354篇
妇产科学   410篇
基础医学   2813篇
口腔科学   512篇
临床医学   1951篇
内科学   4408篇
皮肤病学   590篇
神经病学   1351篇
特种医学   1141篇
外科学   2776篇
综合类   799篇
现状与发展   1篇
一般理论   14篇
预防医学   1087篇
眼科学   731篇
药学   1681篇
中国医学   172篇
肿瘤学   1710篇
  2023年   206篇
  2022年   434篇
  2021年   774篇
  2020年   443篇
  2019年   550篇
  2018年   707篇
  2017年   514篇
  2016年   624篇
  2015年   820篇
  2014年   1010篇
  2013年   1082篇
  2012年   1709篇
  2011年   1662篇
  2010年   936篇
  2009年   836篇
  2008年   1176篇
  2007年   1198篇
  2006年   1136篇
  2005年   1079篇
  2004年   842篇
  2003年   692篇
  2002年   568篇
  2001年   533篇
  2000年   514篇
  1999年   410篇
  1998年   135篇
  1997年   123篇
  1996年   86篇
  1995年   94篇
  1994年   87篇
  1993年   71篇
  1992年   159篇
  1991年   172篇
  1990年   142篇
  1989年   133篇
  1988年   121篇
  1987年   133篇
  1986年   106篇
  1985年   95篇
  1984年   73篇
  1983年   69篇
  1982年   36篇
  1979年   60篇
  1977年   39篇
  1975年   38篇
  1974年   39篇
  1973年   36篇
  1972年   37篇
  1970年   35篇
  1969年   40篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
To determine relatively useful diagnostic procedures of carbon disulfide (CS2) poisoning in terms of validity and cost-effectiveness, several diagnostic tests are evaluated on 1,552 people by prevalence ratio (exposed/nonexposed), dose-response relationship, sensitivity and specificity, and the cost of the tests. Several symptoms with high kappa indices are found to be useful in various combinations, showing a consistent dose-response relationship and high exposed-nonexposed ratio. In clinicopathologic tests on functions of the kidney, liver and hematopoietic systems, eight items out of 22 have been shown to have significant dose-response relationship, mostly in liver function tests. A thorough dental examination failed to identify any useful indicator peculiar to the CS2 poisoning. Unlike Western people, the prevalence of coronary heart disease among Koreans was too low to be useful in the diagnosis of CS2 poisoning. Among four elective tests, i.e., Minnesota Multiphasic Personality Inventory (MMPI), Brain magnetic resonance imaging (MRI), nerve conduction velocity (NCV), and fluorescent angiography (FAG), the NCV appeared to be a more sensitive and specific test than the others are. Combinations of the tests improved the probability of diagnosing CS2 poisoning cases when any one test out of four was positive. Addition of other valid tests increased the probability of excluding non-cases. It was concluded that diagnosis of CS2 poisoning could be made validly and inexpensively if the diagnostic tests were carefully chosen step by step.  相似文献   
132.
(-)-Hydroxycitrate (HCA) is an active ingredient that is extracted from the rind of the Indian fruit, Garcinia cambogia, which is available as an herbal supplement and is used to lose weight. In this study, the acute and chronic effects of HCA on energy metabolism were examined in male Std ddY mice. Mice were placed into metabolic chambers and administered 10 mg HCA or water (control) orally. Serum free fatty acid levels were significantly higher 100 min after administration in the HCA group, but the respiratory exchange ratio was not different from that in the control group. The concentration of glycogen in the gastrocnemius muscle was higher in the HCA group 16 h after administration, and in a separate study, the maximum swimming time until fatigue was slightly longer (P: = 0. 21) than that in the control group on d 1. The difference was significant on d 3 after 3 d of HCA or water administration. Other mice were administered 10 mg HCA or water orally twice a day for 25 d. On d 26, they were placed into metabolic chambers after administration and allowed to rest for 1 h, followed by 1 h of running at 15 m/min. Respiratory gas was monitored. The respiratory exchange ratio was significantly lower in the HCA group during both resting and exercising conditions. These results suggest that chronic administration of HCA promotes lipid oxidation and spares carbohydrate utilization in mice at rest and during running.  相似文献   
133.
Dual therapy has been reported to produce H.pylori eradication rate of 75-80%. This study is designed to determine the efficacy of omeprazole 20 mg bd in combination with amoxycillin 500 mg tid (Group A), amoxycillin 750 mg tds (Group B) and clarithromycin 500 mg tid (Group C) in Singapore. One hundred and forty-eight patients with H. pylori positive duodenal ulcers between ages of 22 and 69 were enrolled from two centres. There were 48 patients in Group A, 50 patients in Group B and 50 patients in Group C. The medication was given for 14 days. The patients were re-evaluated with an upper GI endoscope 4 weeks after cessation of treatment Successful eradication was defined as H.pylori negative on histology and culture. Based on intention to treat analysis, the eradication rate was 47.8% in Group A, 68% in Group B and 66% in Group C. The difference between GroupA and B were statistically significant (p = 0.04). Based on all patient treated analysis, the eradication rate was 57.5% in Group A, 70.7% in Group B and 75% in Group C. The difference in eradication rates was not statistically significant. Adverse events were reported in 21% of all patients with no difference in the adverse event rate between all groups. The eradication rate achieved with dual therapy in this study was similar to that attained in Western population. Higher dose amoxycillin regime gives a significantly higher eradication than a lower dose amoxycillin.  相似文献   
134.
Giant cell arteritis is a chronic granulomatous inflammation of unknown aetiology involving large and medium size arteries in the elderly. It causes acute visual loss from ischaemia to the optic nerves or central retinal artery occlusion. This is a rare cause of anterior ischaemic optic neuropathy in our local population. We present a patient who had bilateral loss of vision from sequential arteritic ischaemic optic neuropathy. She was treated with intravenous steroids immediately. Diagnosis was based on histopathological studies of temporal artery biopsies.  相似文献   
135.
A retrospective review of rubella serological results carried out in the Virus Diagnostic Unit, University Hospital Kuala Lumpur (UHKL) from January 1993 to September 1999 showed the presence of rubella infection annually which appeared to increase periodically every two to three years. There was no statistical significant difference in the rubella positive rate between male and female population aged 14 to 48 years. Congenital rubella infections (CRI) occurred in babies delivered in UHKL yearly from 1993 to 1998 with an average incidence rate of 48 per 100,000 deliveries. Peaks of rubella cases appeared to be followed by an increase in incidence of CRI cases 6 to 9 months later. The study showed that only 50.8% clinically diagnosed rubella was confirmed by laboratory finding. This study also showed an increase of rubella activity for the months of July, August and September 1999 and this may herald an increase of CRI cases in the coming millennium.  相似文献   
136.
Forty patients were treated with ofloxacin for community acquired lower respiratory tract infections. Eighteen pathogens were isolated in sputum; Streptococcus pneumoniae (4) and Haemophilus influenzae (4) were the most common, followed by Klebsiella pneumoniae (3), Klebsiella spp. (2), Staphylococcus anreus (2), Pseudomonas spp. (2), and Pseudomonas aeruginosa (1). Ofloxacin 200 mg every 12 hours was administered for an average of 3.7 days intravenously followed by 5.4 days orally. Response to therapy was judged to be cure in 38 (95%; 95% C.I., 85%-95%) patients, failure in one (2.5%) and "indeterminate" in one (2.5%).  相似文献   
137.
Lim VK 《The Medical journal of Malaysia》2000,55(3):389-97; quiz 398
Over the past two decades there has been numerous new associations between chronic diseases traditionally considered non-infectious with infectious agents. This list of diseases include peptic ulcer, coronary heart disease, neuropsychiatric disorders, haematological disorders and malignancies. These associations have been made possible through improvements in diagnostic tests based on molecular biology techniques. The discovery of these associations is important as it opens up exciting opportunities for the prevention and treatment of many diseases hitherto considered incurable.  相似文献   
138.
OBJECTIVES: To examine the variation in stated management of acute myocardial infarction (AMI) among clinicians of different specialties, and to compare stated with actual practice. DESIGN: Mail survey using a hypothetical case history, and review of medical records. SETTING: 47 public hospitals in New South Wales. SUBJECTS: 224 cardiologists, general/other physicians and general practitioners (GPs) who manage patients with AMI; 390 patients admitted for AMI between February and June 1996. OUTCOME MEASURES: Stated and actual use of treatments and investigations for AMI. RESULTS: Stated use of aspirin, thrombolysis and beta-blockers (95%-100%, 95%-100% and 80%-86%, respectively) was high in all three specialties. Cardiologists were significantly more likely than GPs to state use of heparin (87% v 57%; P < 0.001), ACE inhibitors (84% v 49%; P < 0.001) and echocardiography or gated pool heart scan (79% v 26%; P < 0.001). Stated use of nitrates by cardiologists was significantly lower compared with the other specialties (29% v 50% and 44%; P = 0.027). Actual use of aspirin was high (> 80%) in all specialties. Actual use of thrombolysis was similar to stated use after adjusting for factors such as time to hospital arrival and ST-segment elevation. There were substantial differences between stated and actual use. CONCLUSIONS: There were differences in practice patterns between and among clinicians of different specialties in NSW, consistent with findings from other countries. The high stated and actual use of aspirin and thrombolysis is encouraging.  相似文献   
139.
OBJECTIVE. We describe the CT and pathologic features of malignant papillary neoplasms of the intrahepatic bile ducts in 15 patients. CONCLUSION. CT is a useful technique for revealing intraductal lesions, although the findings are nonspecific and variable. When intraductal masses or nodules are seen with localized dilatation of the intrahepatic bile ducts on CT scans, malignant papillary neoplasms of the intrahepatic bile ducts should be included in the differential diagnosis.  相似文献   
140.
This study was carried out to investigate the modulation of detoxicant enzyme activity and plasma lipidemic levels by 150 kDa glycoprotein isolated from Solanum nigrum Linne (SNL), which has been used as a hepatoprotective and anticancer agent in folk medicine. Our results in this study showed that SNL glycoprotein has a band with 150 kDa on the 10% sodium dodecyl sulfate polyacrylamide gel, and that it has a strong scavenging activity against lipid peroxyl radicals. We also evaluated the lipidemic levels of SNL glycoprotein, based on lipoproteins and activities of detoxicant enzymes in treatment with Triton WR-1339 or corn oil in vivo. When mice were treated with either Triton WR-1339 or corn oil in the absence of SNL glycoprotein, the number of plasma lipoproteins [triglyceride (TG), total cholesterol (TC) and low density lipoprotein (LDL)] increased. However, when the mice were treated with either Triton WR-1339 or corn oil in the presence of SNL glycoprotein, the plasma lipoprotein levels (TG, TC and LDL) were significantly reduced. Similar results of SNL glycoprotein treatment were also produced in the activities of detoxicant enzymes. Namely, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were remarkably increased after treatment with SNL glycoprotein. In addition, the activity of hepatic 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase was reduced by SNL glycoprotein in cholestyramine-treated mice. For example, we found that it inhibits the activity of cholestyramine-induced hepatic HMG-CoA reductase at 40 microg head body weight g(-1) SNL glycoprotein. Collectively, these results pointed out that SNL glycoprotein can enhance the activities of detoxicant enzymes and bring about the inhibition of HMG-CoA reductase activity in vivo. Therefore, we speculate that SNL glycoprotein can be used as a cholesterol-lowering agent even at low concentrations.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号