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   848篇
  免费   94篇
  国内免费   1篇
耳鼻咽喉   1篇
儿科学   30篇
妇产科学   33篇
基础医学   126篇
口腔科学   5篇
临床医学   94篇
内科学   206篇
皮肤病学   3篇
神经病学   39篇
特种医学   22篇
外科学   79篇
综合类   50篇
一般理论   1篇
预防医学   121篇
眼科学   40篇
药学   41篇
中国医学   2篇
肿瘤学   50篇
  2022年   9篇
  2021年   25篇
  2020年   13篇
  2019年   16篇
  2018年   8篇
  2017年   9篇
  2016年   9篇
  2015年   13篇
  2014年   19篇
  2013年   25篇
  2012年   27篇
  2011年   43篇
  2010年   15篇
  2009年   17篇
  2008年   22篇
  2007年   31篇
  2006年   33篇
  2005年   39篇
  2004年   36篇
  2003年   31篇
  2002年   30篇
  2001年   17篇
  2000年   20篇
  1999年   24篇
  1998年   12篇
  1997年   8篇
  1995年   9篇
  1992年   14篇
  1991年   22篇
  1990年   23篇
  1989年   21篇
  1988年   26篇
  1987年   23篇
  1986年   15篇
  1985年   23篇
  1984年   12篇
  1981年   8篇
  1980年   11篇
  1979年   15篇
  1978年   15篇
  1977年   10篇
  1976年   13篇
  1974年   7篇
  1973年   9篇
  1972年   14篇
  1970年   13篇
  1969年   9篇
  1968年   8篇
  1967年   8篇
  1965年   8篇
排序方式: 共有943条查询结果,搜索用时 31 毫秒
81.
82.
Forty-nine patients with active rheumatoid arthritis completed a 24-week, prospective, double-blind, randomized study of dietary supplementation with 2 different dosages of fish oil and 1 dosage of olive oil. Clinical evaluations were performed at baseline and every 6 weeks thereafter, and immunologic variables were measured at baseline and after 24 weeks of study. The 3 groups of patients were matched for age, sex, disease severity, and use of disease-modifying antirheumatic drugs (DMARDs). Subjects continued receiving DMARDs and other background medications without change during the study. Twenty patients consumed daily dietary supplements of n3 fatty acids containing 27 mg/kg eicosapentaenoic acid (EPA) and 18 mg/kg docosahexaenoic acid (DHA) (low dose), 17 patients ingested 54 mg/kg EPA and 36 mg/kg DHA (high dose), and 12 patients ingested olive oil capsules containing 6.8 gm of oleic acid. Significant improvements from baseline in the number of tender joints were noted in the low-dose group at week 24 (P = 0.05) and in the high-dose group at week 18 (P = 0.04) and 24 (P = 0.02). Significant decreases from baseline in the number of swollen joints were noted in the low-dose group at weeks 12 (P = 0.003), 18 (P = 0.002), and 24 (P = 0.001) and in the high-dose group at weeks 12 (P = 0.0001), 18 (P = 0.008), and 24 (P = 0.02). A total of 5 of 45 clinical measures were significantly changed from baseline in the olive oil group, 8 of 45 in the low-dose fish oil group, and 21 of 45 in the high-dose fish oil group during the study (P = 0.0002). Neutrophil leukotriene B4 production decreased by 19% from baseline in the low-dose fish oil group (P = 0.0003) and 20% in the high-dose group (P = 0.03), while macrophage interleukin-1 production decreased by 38.5% in the olive oil group (P not significant), 40.6% in the low-dose group (P = 0.06), and 54.7% in the high-dose group (P = 0.0005). Tritiated thymidine incorporation in peripheral blood mononuclear cells after stimulation with concanavalin A increased significantly in all 3 groups after 24 weeks, compared with baseline values. We conclude that the clinical benefits of dietary supplementation with omega-3 fatty acids are more commonly observed in patients consuming higher dosages of fish oil for time intervals that are longer than those previously studied. Dietary supplementation with olive oil is also associated with certain changes in immune function, which require further investigation.  相似文献   
83.
Human pancreas contains receptors for estrogens and androgens as well as aromatase activity. FAM chemotherapy was administered to 14 patients with pancreatic cancer (seven at Stage IV). The median survival of these patients was 24.4 +/- 4.8 weeks. FAM chemotherapy plus aminoglutethimide/hydrocortisone (AG/HC) (250 mg bid AG + 20 mg bid HC) was administered to 14 patients (seven at stage IV). The median survival of this group was 17.3 +/- 2.9 weeks (P = 0.74 vs FAM alone). We conclude that addition of AG/HC does not add to the survival of patients with carcinoma of the pancreas treated with chemotherapy.  相似文献   
84.
Coronary heart disease (CHD) is a multifactorial disease and CHD risk should be estimated by assessing all cardiovascular risk factors simultaneously. Simply adding up the number of factors with 'at risk' values fails to identify high-risk subjects with multiple risk factors at moderately elevated values. A more efficient approach is to use a quantitative multivariate risk score. A number of overseas studies have produced CHD risk scoring systems for men. There are few risk scores developed for women and no CHD risk scores have been developed from Australian data. This study used data on CHD risk factors and morbidity/mortality follow-up for the 1978 Busselton Health Survey participants to provide age-specific estimates of absolute risk of CHD hospitalisation or death, and to develop multivariate CHD risk scoring systems for men and women. The scores are based on age, blood pressure, anti-hypertensive medication, total and HDL cholesterol, smoking, diabetes, left ventricular hypertrophy and previous history of CHD. The generalisability and applicability of these risk estimation systems to Australian populations in the late 1990s is discussed.  相似文献   
85.
Application of bioluminescent urine screens in a tertiary care facility   总被引:1,自引:0,他引:1  
Two adenosine triphosphate (ATP)-detection systems for quantitating bacteriuria, the LUMAC (noncentrifugation method) and MONOLIGHT (centrifugation method) urine screens, were separately evaluated for their capacity to detect bacteriuria in specimens from patients at a tertiary care teaching hospital. Results of each study were compared with the findings of conventional culture. Indices of test efficacy, sensitivity/predictive value for a negative test, were as follows: at greater than or equal to 10(4) CFU/ml--LUMAC 88%/93% and MONOLIGHT 82%/88%; and at greater than or equal to 10(5) CFU/ml--LUMAC 99%/99% and MONOLIGHT 97%/99%. Both systems were satisfactory urine screens for catheterized and midstream urine specimens when used at the traditional level of significance (greater than or equal to 10(5) CFU/ml). An assessment of the MONOLIGHT noncentrifugation protocol demonstrated efficacy of the system to detect significant bacteriuria at greater than or equal to 10(5) CFU/ml. Decreased numbers of false-positive results compared to the centrifugation method were obtained with this assay. False-positive and false-negative results were attributable to threshold sensitivity of the instruments. The presence of somatic cells and yeasts were associated with false-positive results. False-positive results might stem from the inability of conventional culture to recover selected microorganisms. Time and cost analyses of the LUMAC system indicated that significant savings over conventional methodology were not effected.  相似文献   
86.
87.
Hypofibrinogenemia and disseminated intravascular coagulation are common events in patients with metastatic prostate carcinoma. This study tests the hypothesis that prostate tumor growth and metastasis is associated with sustained activation of fibrinolysis secondary to increased release of plasminogen activator. We implanted an androgen-insensitive prostate tumor into an inbred strain of rats and serially measured plasminogen, plasminogen activator, plasmin and fibrinogen. Control groups included animals without tumor and a group implanted with transitional cell bladder carcinoma, a locally infiltrating tumor not usually associated with hemostatic complications. Our results showed a significant and steady rise in plasma plasminogen activator, plasmin and fibrinogen levels in animals implanted with prostate cancer. This, however, is not specific for prostate tumor. Similar, perhaps more profound changes were noted in animals implanted with the transitional cell carcinoma.  相似文献   
88.
89.
90.
Improved treatments for chronic hepatitis C virus (HCV) infection are needed due to the suboptimal response rates and deleterious side effects associated with current treatment options. The triphosphates of 2'-C-methyl-adenosine and 2'-C-methyl-guanosine were previously shown to be potent inhibitors of the HCV RNA-dependent RNA polymerase (RdRp) that is responsible for the replication of viral RNA in cells. Here we demonstrate that the inclusion of a 7-deaza modification in a series of purine nucleoside triphosphates results in an increase in inhibitory potency against the HCV RdRp and improved pharmacokinetic properties. Notably, incorporation of the 7-deaza modification into 2'-C-methyl-adenosine results in an inhibitor with a 20-fold-increased potency as the 5'-triphosphate in HCV RdRp assays while maintaining the inhibitory potency of the nucleoside in the bicistronic HCV replicon and with reduced cellular toxicity. In contrast, while 7-deaza-2'-C-methyl-GTP also displays enhanced inhibitory potency in enzyme assays, due to poor cellular penetration and/or metabolism, the nucleoside does not inhibit replication of a bicistronic HCV replicon in cell culture. 7-Deaza-2'-C-methyl-adenosine displays promising in vivo pharmacokinetics in three animal species, as well as an acute oral lethal dose in excess of 2,000 mg/kg of body weight in mice. Taken together, these data demonstrate that 7-deaza-2'-C-methyl-adenosine is an attractive candidate for further investigation as a potential treatment for HCV infection.  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