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   174篇
  免费   5篇
耳鼻咽喉   3篇
妇产科学   2篇
基础医学   30篇
临床医学   14篇
内科学   27篇
皮肤病学   1篇
神经病学   24篇
特种医学   4篇
外科学   5篇
预防医学   24篇
药学   21篇
中国医学   1篇
肿瘤学   23篇
  2022年   2篇
  2020年   2篇
  2019年   5篇
  2018年   2篇
  2017年   1篇
  2016年   4篇
  2015年   6篇
  2014年   6篇
  2013年   10篇
  2012年   12篇
  2011年   12篇
  2010年   6篇
  2009年   8篇
  2008年   6篇
  2007年   6篇
  2006年   7篇
  2005年   10篇
  2004年   5篇
  2003年   10篇
  2002年   6篇
  2001年   3篇
  2000年   6篇
  1999年   7篇
  1998年   1篇
  1997年   1篇
  1996年   4篇
  1994年   1篇
  1993年   3篇
  1992年   2篇
  1990年   3篇
  1989年   3篇
  1988年   3篇
  1987年   5篇
  1986年   3篇
  1985年   3篇
  1983年   2篇
  1981年   1篇
  1980年   1篇
  1975年   1篇
排序方式: 共有179条查询结果,搜索用时 46 毫秒
171.
Introduction Advances in diagnosis and treatment in oncology combined with technical advances in radiotherapy have resulted in qualitative and quantitative changes in the use of radiation to treat breast cancer. Objective The objective was to analyse changes in radiation indications from 1990 to the present time and their consequences in the use of treatments units. Methods and material From January 1990 to December 2005, 4545 radiation treatments for breast cancer were performed, classified as radical after conservative surgery, radical after mastectomy or palliative. Data are presented as relative frequencies and as 3-year period groups. Results An increase in the proportion of treatments for breast cancer and in treatment unit use distribution is observed. Radical treatments have increased over time, ranging from 55% in the first 3-year period group to 82% in the last one. Unit treatment distribution analysis is similar, but with a less important increase, rising from 85% to 95%. A rise in conservative treatment is also observed, from 43% to 75%. Conclusions An increase in breast cancer incidence is observed and there was also an increase in irradiation after conservative treatment. On the contrary, probably due to the rise in the use of systemic treatments, a decrease in post-mastectomy irradiation and palliative treatments is shown.  相似文献   
172.
173.
174.
1. Angiotensin converting enzyme (ACE) inhibitors are under study in ischaemic heart diseases, their mechanism of action being still unknown. 2. The anti-ischaemic effect of trandolapril and the possible involvement of a bradykinin-modulation on endothelial constitutive nitric oxide synthase (eNOS) in exerting this effect, were investigated. 3. Three doses of trandolapril, chronically administered in vivo, were studied in isolated perfused rat hearts subjected to global ischaemia followed by reperfusion. 4. Trandolapril has an anti-ischaemic effect. The dose of 0.3 mg kg(-1) exerted the best effect reducing diastolic pressure increase during ischaemia (from 33.0+/-4.5 to 14.0+/-5.2 mmHg; P<0.05 vs control) and reperfusion (from 86.1+/-9.4 to 22.2+/-4.1 mmHg; P<0.01 vs control), improving functional recovery, counteracting creatine phosphokinase release and ameliorating energy metabolism after reperfusion. 5. Trandolapril down-regulated the baseline developed pressure. 6. Trandolapril increased myocardial bradykinin content (from 31.8+/-6.1 to 54.8+/-7.5 fmol/gww; P<0.05, at baseline) and eNOS expression and activity in aortic endothelium (both P<0.01 vs control) and in cardiac myocytes (from 11.3+/-1.5 to 17.0+/-2.0 mUOD microg protein(-1) and from 0.62+/-0.05 to 0.80+/-0.06 pmol mg prot(-1) min(-1); both P<0.05 vs control). 7. HOE 140 (a bradykinin B(2) receptor antagonist) and NOS inhibitors counteracted the above-reported effects. 8. There was a negative correlation between myocyte's eNOS up-regulation and myocardial contraction down-regulation. 9. Our findings suggest that the down-regulation exerted by trandolapril on baseline cardiac contractility, through a bradykinin-mediated increase in NO production, plays a crucial role in the anti-ischaemic effect of trandolapril by reducing energy breakdown during ischaemia.  相似文献   
175.
The β-adrenergic pathway may have a role in the pathophysiology of ischemic syndromes characterised by reversible left ventricular dysfunction, such as myocardial stunning and other clinical conditions of unstable angina or coronary spasms, or chronic reversible left ventricular dysfunction, which might be a consequence of repeated events of short-term ischemia (“repetitive stunning”). A partial-to-total occlusion of the left anterior descending coronary artery in pigs was used to induce short periods of ischemia (total ischemic time 12 ± 2 min). Hypokinesis and dyskinesis of the myocardium were considered signs of myocardial dysfunction. We found a maintained function of the β-adrenergic signalling system. Density and affinity of β-adrenergic receptors were not different in stunned and non-ischemic regions, nor were cyclic AMP and cyclic GMP intracellular contents and ratio, nor well as the ratio of stimulatory/inhibitory G protein a subunits. Our findings are in agreement with a maintained β-adrenergic signalling system in the pathophysiology of chronic reversible left ventricular dysfunction. Received: 25 September 2000 / Returned for 1. revision: 9 October 2000 / 1. Revision received: 22 November 2000 / Returned for 2. revision: 7 December 2000 / 2. Revision received: 8 January 2001 / Accepted: 11 January 2001  相似文献   
176.
OBJECTIVE: to investigate the changes of pyridine nucleotides and thiol redox state in cardiac tissue following ischemia and reperfusion. NADH/NAD and NADPH/NADP redox couples were specifically studied and the influence of NADPH availability on cellular thiol redox was also investigated. METHODS: isolated rabbit hearts were Langendorff perfused and subjected to a protocol of ischemia and reperfusion. An improved technique for extraction and selective quantitation of pyridine nucleotides was applied. RESULTS: ischemia and reperfusion induced an increase in diastolic pressure, limited recovery in developed pressure and loss of creatine phosphokinase. Creatine phosphate and ATP were decreased by ischemia and only partially recovered during reperfusion. NADH was increased (from 0. 36+/-0.04 to 1.96+/-0.15 micromol/g dry wt. in ischemia, P<0.001), whereas NADPH decreased during ischemia (from 0.78+/-0.04 to 0. 50+/-0.06 micromol/g dry wt., P<0.01) and reperfusion (0.45+/-0.03 micromol/g dry wt.). Furthermore, we observed: (a) release of reduced (GSH) and oxidised glutathione (GSSG) during reperfusion; (b) decreased content of reduced sulfhydryl groups during ischemia and reperfusion (GSH: from 10.02+/-0.76 to 7.11+/-0.81 nmol/mg protein, P<0.05, and to 5.48+/-0.57 nmol/mg protein; protein-SH: from 280.42+/-12.16 to 135.11+/-17.00 nmol/mg protein, P<0.001, and to 190.21+/-11.98 nmol/mg protein); (c) increased content in GSSG during reperfusion (from 0.17+/-0.02 to 0.36+/-0.02 nmol/mg protein, P<0.001); (d) increased content in mixed disulphides during ischemia (from 6.14+/-0.13 to 8.31+/-0.44 nmol/mg protein, P<0.01) and reperfusion (to 9.87+/-0.82 nmol/mg protein, P<0.01). CONCLUSIONS: under severe low-flow ischemia, myocardial NADPH levels can decrease despite the accumulation of NADH. The reduced myocardial capacity to maintain NADPH/NADP redox potential can result in thiol redox state changes. These abnormalities may have important consequences on cellular function and viability.  相似文献   
177.
OBJECTIVES: To differentiate the impact of the beta-blocking and the anti-oxidant activity of carvedilol in maintaining myocardium viability. METHODS: Isolated rabbit hearts, subjected to aerobic perfusion, or low-flow ischaemia followed by reperfusion, were treated with two doses of carvedilol, one dose (2.0 microM) with marked negative inotropic effect due to beta-blockage and the other (0.1 microM) with no beta-blockage nor negative inotropism. Carvedilol was compared with two doses of propranolol, 1.0 - without - and 5.0 microM - with negative inotropic effect. Anti-oxidant activity was measured as the capacity to counteract the occurrence of oxidative stress and myocardium viability as recovery of left ventricular function on reperfusion, membrane damage and energetic status. RESULTS: Carvedilol counteracted the ischemia and reperfusion induced oxidative stress: myocardial content of reduced glutathione, protein and non-protein sulfhydryl groups after ischaemia and particularly after reperfusion, was higher in hearts treated with carvedilol, while the myocardial content of oxidised glutathione was significantly reduced (0.30+/-0.03 and 0.21+/-0.02 vs. 0.39+/-0.03 nmol/mg prot, both P<0.01, in 0.1 and 2.0 microM). At the same time, carvedilol improved myocardium viability independently from its beta-blocking effect. On the contrary, propranolol maintained viability only at the higher dose, although to a lesser extent than carvedilol. This suggests that the effects of propranolol are dependent on energy saving due to negative inotropism. The extra-protection observed with carvedilol at both doses is likely due to its anti-oxidant effect. CONCLUSIONS: Our data show that the anti-oxidant activity of carvedilol is relevant for the maintenance of myocardium viability.  相似文献   
178.
179.
Objective: To evaluate the feasibility and safety of home rehabilitation of the hand using a robotic glove, and, in addition, its effectiveness, in hemiplegic patients after stroke.

Methods: In this non-randomized pilot study, 21 hemiplegic stroke patients (Ashworth spasticity index ≤ 3) were prescribed, after in-hospital rehabilitation, a 2-month home-program of intensive hand training using the Gloreha Lite glove that provides computer-controlled passive mobilization of the fingers. Feasibility was measured by: number of patients who completed the home-program, minutes of exercise and number of sessions/patient performed. Safety was assessed by: hand pain with a visual analog scale (VAS), Ashworth spasticity index for finger flexors, opponents of the thumb and wrist flexors, and hand edema (circumference of forearm, wrist and fingers), measured at start (T0) and end (T1) of rehabilitation. Hand motor function (Motricity Index, MI), fine manual dexterity (Nine Hole Peg Test, NHPT) and strength (Grip test) were also measured at T0 and T1.

Results: Patients performed, over a mean period 56 (49–63) days, a total of 1699 (1353–2045) min/patient of exercise with Gloreha Lite, 5.1 (4.3–5.8) days/week. Seventeen patients (81%) completed the full program. The mean VAS score of hand pain, Ashworth spasticity index and hand edema did not change significantly at T1 compared to T0. The MI, NHPT and Grip test improved significantly (p = 0.0020, 0.0156 and 0.0024, respectively) compared to baseline.

Conclusion: Gloreha Lite is feasible and safe for use in home rehabilitation. The efficacy data show a therapeutic effect which need to be confirmed by a randomized controlled study.  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