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   1893篇
  免费   107篇
  国内免费   23篇
耳鼻咽喉   10篇
儿科学   89篇
妇产科学   62篇
基础医学   204篇
口腔科学   30篇
临床医学   116篇
内科学   579篇
皮肤病学   17篇
神经病学   118篇
特种医学   131篇
外科学   294篇
综合类   10篇
预防医学   76篇
眼科学   6篇
药学   120篇
中国医学   6篇
肿瘤学   155篇
  2023年   4篇
  2022年   11篇
  2021年   24篇
  2020年   15篇
  2019年   29篇
  2018年   40篇
  2017年   29篇
  2016年   25篇
  2015年   41篇
  2014年   46篇
  2013年   78篇
  2012年   81篇
  2011年   70篇
  2010年   57篇
  2009年   68篇
  2008年   83篇
  2007年   98篇
  2006年   85篇
  2005年   90篇
  2004年   104篇
  2003年   78篇
  2002年   74篇
  2001年   82篇
  2000年   62篇
  1999年   68篇
  1998年   49篇
  1997年   47篇
  1996年   40篇
  1995年   42篇
  1994年   39篇
  1993年   24篇
  1992年   25篇
  1991年   23篇
  1990年   25篇
  1989年   30篇
  1988年   28篇
  1987年   21篇
  1986年   25篇
  1985年   27篇
  1984年   19篇
  1983年   12篇
  1982年   15篇
  1981年   12篇
  1980年   9篇
  1979年   16篇
  1978年   13篇
  1976年   4篇
  1975年   9篇
  1973年   4篇
  1969年   4篇
排序方式: 共有2023条查询结果,搜索用时 15 毫秒
1.
The concentrations of beta-endorphin and cholecystokinin were measured in fresh resting peripheral mononuclear cells obtained from rats and human subjects in basal conditions and after different pharmacological treatments. Both in the human and the rat, beta-endorphin concentrations in mononuclear cells, increased after treatment with serotoninergic agonists, decreased after dopaminergic or GABAergic drugs, while the respective antagonists exerted the opposite effect. In vitro, serotoninergic and GABAergic compounds confirmed their roles in the modulation of beta-endorphin in mononuclear cells. Cholecystokinin was never affected by the pharmacological treatments.  相似文献   
2.
BACKGROUND: Chronic kidney disease patients who are resistant to erythropoietin (EPO) treatment may suffer from malnutrition and/or inflammation. METHODS: In a cross-sectional study of haemodialysis patients, we investigated the relationship between the natural logarithm of the weekly EPO dose normalized for post-dialysis body weight and outcome measures of nutrition and/or inflammation [BMI, albumin and C reactive protein (CRP)] by means of multiple linear regression analysis. On the basis of the decile distribution of weekly EPO doses, we also evaluated four groups of patients: untreated, hyper-responders, normo-responders and hypo-responders. RESULTS: Six hundred and seventy-seven adult haemodialysis patients were recruited from five Italian centres. BMI and albumin were lower in the hypo-responders than in the other groups (21.3+/-3.8 vs 24.4+/-4.7 kg/m(2), P<0.001; and 3.8+/-0.6 vs 4.1+/-0.4 g/dl, P<0.001), whereas the median CRP level was higher (1.9 vs 0.8 mg/dl, P = 0.004). The median weekly EPO dose ranged from 30 IU/kg/week in the hyper-responsive group to 263 IU/kg/week in the hypo-responsive group. Transferrin saturation linearly decreased from the hyper- to hypo-responsive group (37+/-15 to 25+/-10%, P = 0.003), without any differences in transferrin levels. Ferritin levels were lower in the hypo-responsive than in the other patients (median 318 vs 445 ng/ml, P = 0.01). At multiple linear regression analysis, haemoglobin, BMI, albumin, CRP and serum iron levels were independently associated with the natural logarithm of the weekly EPO dose (R(2) = 0.22). CONCLUSIONS: Our findings support a clear association between EPO responsiveness and nutritional and inflammation variables in haemodialysis patients; iron deficiency is still a major cause of hypo-responsiveness.  相似文献   
3.
We have reviewed the incidence of cisplatin-induced anaemia in patients affected with solid tumours treated with at least three courses of first-line cisplatincontaining regimens. In our experience, a low percentage (5%) of patients required transfusions of red blood cells. We think it is of the utmost importance to adopt uniform criteria in monitoring and treatment of patients at risk of developing cisplatin anaemia and to identify subsets of patients to eventually treat with erythropoietin.  相似文献   
4.
The synthesis of phenothiazine and anthraquinone derivatives, bearing at least one fragment present in lotifazole, is reported. Some of the new compounds showed antitumor activity in vitro (P388 leukemia cells) and in vivo (Ehrlich ascites tumor cells in mice).  相似文献   
5.
6.
BACKGROUND: Sodium removal (NaR) may have a major impact on the survival of peritoneal dialysis patients. The dialysate/plasma sodium concentration ratio (D/P(Na)) is an indirect index of transcellular water transport by aquaporin channels, and thus of ultrafiltration. Sodium concentration can be assessed by means of flame photometry (F), and direct (D-ISE) or indirect ion-selective electrodes (I-ISE), but these methods have different properties. I-ISE is being used increasingly in clinical laboratories. The aim of this study was to evaluate NaR and D/P(Na) using the three different measurement methods. METHODS: We performed peritoneal equilibration tests (PETs) in 44 peritoneal dialysis patients and calculated the NaR. We also calculated D/P(Na) during the test; plasma and dialysate sodium concentrations were measured by F, D-ISE and I-ISE. RESULTS: NaR was lower (P<0.001) with D-ISE (69+/-29 mmol) than with F (81+/-29 mmol) or I-ISE (79+/-28 mmol). D/P(Na) was also lower at baseline (0.92+/-0.02 vs 0.95+/-0.02 and 0.95+/-0.02; P<0.001), after 60 min (0.87+/-0.03 vs 0.90+/-0.03 and 0.90+/-0.03; P<0.001) and at the end of PET (0.88+/-0.04 vs 0.92+/-0.04 and 0.92+/-0.04; P<0.001) when measured by D-ISE in comparison with F and I-ISE, respectively. CONCLUSIONS: NaR and D/P(Na) were lower when measured by the D-ISE method compared with the F and I-ISE methods. NaR and D/P(Na) were similar when measured by F or I-ISE. I-ISE can be used reliably in the evaluation of NaR and D/P(Na) in everyday clinical practice of peritoneal dialysis.  相似文献   
7.
A simple, rapid, and sensitive method for the determination of aspirin and salicylic acid in plasma of uremic patients is reported. After extraction with hexane, aspirin (ASA) and salicylic acid (SA) were quantified by high-performance liquid chromatography (HPLC) with ultraviolet detection at 229 nm. ASA and SA concentrations and peak-height ratios were linearly related up to 20 micrograms/ml. The lower limit of sensitivity was 0.1 microgram/ml for both compounds. The average recoveries of aspirin and salicylic acid were 27 and 54%, respectively. This procedure offers better performance than do previously described methods. The sample clean-up allows quantitation of a low concentration of aspirin in uremic patients' plasma, commonly rich in interfering endogenous substances.  相似文献   
8.
9.
10.
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