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   2712篇
  免费   113篇
  国内免费   7篇
耳鼻咽喉   24篇
儿科学   64篇
妇产科学   93篇
基础医学   314篇
口腔科学   44篇
临床医学   233篇
内科学   476篇
皮肤病学   27篇
神经病学   309篇
特种医学   107篇
外科学   390篇
综合类   19篇
一般理论   1篇
预防医学   213篇
眼科学   21篇
药学   261篇
中国医学   4篇
肿瘤学   232篇
  2021年   31篇
  2020年   27篇
  2019年   38篇
  2018年   29篇
  2017年   31篇
  2016年   37篇
  2015年   39篇
  2014年   66篇
  2013年   116篇
  2012年   146篇
  2011年   147篇
  2010年   110篇
  2009年   83篇
  2008年   129篇
  2007年   171篇
  2006年   134篇
  2005年   152篇
  2004年   164篇
  2003年   127篇
  2002年   145篇
  2001年   38篇
  2000年   30篇
  1999年   46篇
  1998年   33篇
  1997年   29篇
  1996年   30篇
  1995年   28篇
  1994年   34篇
  1993年   26篇
  1992年   29篇
  1991年   28篇
  1990年   38篇
  1989年   29篇
  1988年   37篇
  1987年   26篇
  1986年   33篇
  1985年   29篇
  1984年   33篇
  1983年   17篇
  1982年   22篇
  1981年   27篇
  1980年   18篇
  1979年   25篇
  1978年   19篇
  1977年   17篇
  1975年   21篇
  1974年   23篇
  1973年   19篇
  1972年   22篇
  1971年   12篇
排序方式: 共有2832条查询结果,搜索用时 15 毫秒
1.
OBJECTIVE: Analysis of the effects of a comprehensive focal spasticity program in adult patients. DESIGN: Retrospective study of an out-patient cohort. PATIENTS: One hundred patients were enrolled in the study (54 men and 46 women, mean age 41 years (SD 14). Cerebral palsy and stroke were equally common (80% in total). The remaining patients had miscellaneous diagnoses, including traumatic brain injury. METHODS: On average 230 units (SD 101) of botulinum toxin A Botox was given for 227 principal therapy targets chosen by the patient or the caregiver. One patient could have several targets for therapy. Administration of botulinum toxin was combined with 260 additional therapeutic interventions, most of which were forms of physical therapy. The effects were assessed after 6 weeks and compared with baseline functional abilities 1-2 weeks prior to therapy. RESULTS: Improvement was observed for 211 (93%) therapy targets, no change in 15 (7%), and impairment in 1, corresponding to an overall improvement in 90 patients (90%), 9 unchanged (9%) and worsening in 1. Spasticity assessment (Ashworth scale 0-4; 30 patients) showed a statistically significant improvement (median at baseline was 3 vs 2 after therapy, mean difference 1.2, p<0.001). CONCLUSION: Improvement was observed in >or=90% of patients and in their principal therapeutic targets in a cohort receiving their first focal spasticity treatment with botulinum toxin A and additional therapy. A strict strategy for patient selection and comprehensive management was followed.  相似文献   
2.
Background and Purpose . Patients with multiple sclerosis (MS) tend to have movement difficulties, and the effect of physiotherapy for this group of patients has been subjected to limited systematic research. In the present study physiotherapy based on the Bobath concept, applied to MS patients with balance and gait problems, was evaluated. The ability of different functional tests to demonstrate change was evaluated. Method . A single‐subject experimental study design with ABAA phases was used, and two patients with relapsing–remitting MS in stable phase were treated. Tests were performed 12 times, three at each phase: A (at baseline); B (during treatment); A (immediately after treatment); and A (after two months). The key feature of treatment was facilitation of postural activity and selective control of movement. Several performance and self‐report measures and interviews were used. Results . After intervention, improved balance was shown by the Berg Balance Scale (BBS) in both patients, and improved quality of gait was indicated by the Rivermead Visual Gait Assessment (RVGA). The patients also reported improved balance and gait function in the interviews and scored their condition as ‘much improved’. Gait parameters, recorded by an electronic walkway, changed, but differently in the two patients. Among the physical performance tests the BBS and the RVGA demonstrated the highest change, while no or minimal change was demonstrated by the Rivermead Mobility Index (RMI) and Ratings of Perceived Exertion (RPE). Conclusion . The findings indicate that balance and gait can be improved after physiotherapy based on the Bobath concept, but this should be further evaluated in larger controlled trials of patients with MS. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   
3.
4.
The hypothesis of genetic defects in glycosaminoglycan (GAG) regulation among patients with insulin-dependent diabetes mellitus (IDDM) and nephropathy was assessed by studies in tissue cultures of fibroblasts obtained from 7 patients with normal urinary albumin excretion, 11 patients with diabetic nephropathy, and 6 nondiabetic control subjects. The incorporation of [2H] glucosamine and [35S] sulfate into hyaluronic acid (HA), chondroitin sulfate and dermatan sulfate (CS + DS), and heparan sulfate (HS) was measured in cells, matrix, and medium and related to micrograms of tissue protein. Large interindividual variations were seen in all three groups, and the incorporation of [3H] glucosamine into HA, CS + DS, and HS and [35S] sulfate into CS + DS and HS were not significantly different between the three groups. However, the fractional incorporation of [3H]glucosamine into HS was significantly reduced in diabetic patients with nephropathy compared with control subjects. This was the case not only when related to the total amount of GAGs (P = 0.014) but also when related to HA (P = 0.014). No significant difference was seen between control subjects and normoalbuminuric diabetic patients. The degree of N-sulfation of HS was not significantly different between the experimental groups. The results suggest that patients with diabetic nephropathy may suffer from deficiencies of coordinate regulation in the biosynthesis of GAG in fibroblasts, which may lead to a reduced density of HS in the extracellular matrix. If these changes reflect alterations in the biosynthesis of GAG from endothelial, myomedial, and mesangial cells, this observation may be relevant for the pathogenesis of severe diabetic complications.  相似文献   
5.
6.
Heparin or heparan sulfate--what is the difference?   总被引:3,自引:0,他引:3  
  相似文献   
7.
Objective: The scientific quality of research is an important ethical issue. To clarify the quality of research projects in pharmacotherapy/pharmacology, 40 randomly selected research projects in pharmacotherapy/pharmacology submitted to a research ethics committee were reviewed. Results: Eight of the projects would not have contributed new knowledge nor were they necessary as controls for the results of previous research. Fifteen of the research protocols were of good quality, 15 could be used after revisions, and 10 were unfit for use. Eleven of the research projects were not finished 5 years after they were started. A written report was produced from 26 of the projects. Nine were of good quality and could be accepted for publication in a medical journal, 10 of the reports were in need of revision before publication, and 7 should not be accepted for publication. Conclusion: Research in this field ought to be improved, and ways to improve the standard of clinical trials in pharmacotherapy are dicussed. Received: 1 April 1996 / Accepted in revised form: 28 June 1996  相似文献   
8.
By means of positron emission tomography the uptake and kinetics of N-(methyl-11C)clozapine in different brain regions have been studied in Rhesus monkeys. 11C-clozapine rapidly entered the brain and maximum radioactive uptake was seen 5–12 min after administration. Highest uptake was measured in the striatum. Other regions with an uptake higher than in the cerebellum were thalamus and mesencephalon. The radioactivity from different brain regions decreased with an elimination half-life of about 5 h and parallelled the plasma kinetics of unlabelled clozapine. The striatum/cerebellum ratio of 11C-clozapine-derived radioactivity remained constant during the period studied and did not change after pretreatment with atropine. In contrast, the striatum/cerebellum ratio was somewhat lower after pretreatment with N-methylspiperone (NMSP), indicating competition for the same binding sites in the striatum. After pretreatment with increasing doses of clozapine, a dose-dependent protection of binding sites in the striatum for 11C-NMSP was seen. It is concluded that clozapine is more loosely bound to dopamine receptors in the striatum than N-methylspiperone and that the kinetics of clozapine in the brain parallel that in the plasma. The binding properties of clozapine within the brain may explain some of the clinical properties of the drug.  相似文献   
9.
Interactions between 5-hydroxytryptamine (5-HT) and substance P (SP) in the mouse spinal cord were investigated using the tail-flick test and the behavioral response evoked by intrathecal (i.th.) SP or i.th. 5-HT. I.th. injection of 5-HT (20 μg) or the 5-HT1 receptor agonists(+)-8-hydroxy-2-(di-n-propylamino)tetralin ((+)-8-OH-DPAT) (20 μg) or 5-methoxy-3(1,2,3,6-tetrahydropyridine-4-yl)-1H-indole (RU 24969) (20 μg) markedly inhibited the tail-flick reflex. The effect of these compounds was reduced when SP (5 μg) was given i.th. 55 min, or 55 and 45 min before the agonists. The tail-flick latencies recorded 5 min before injection of a 5-HT agonist were similar in animals treated with SP or vehicle. The changes in the tail-flick test were not due to changes in tail skin temperature since only minimal differences in the skin temperature were recorded between the groups injected with SP or vehicle. I.th. injection of SP (10 ng) or 5-HT (2 μg) produced a similar behavioral response consisting of biting, licking and scratching of the caudal part of the body, indicative of nociceptive stimulation. The responses both to i.th. SP and 5-HT were reduced after i.th. application of SP receptor antagonist [d-Arg1,d-Trp7,9,Leu11]-SP (Spantide) (5 μg), as well as 5 min after i.th. injection of the 5-HT receptor antagonist metergoline (4 μg). The data may indicate functional interactions between SP and 5-HT in the mouse spinal cord, which may take place in neurons involved in the processing of nociception.  相似文献   
10.
AIM: To determine whether axillary recurrence reflects inadequate axillary treatment or adverse pathological features. METHODS: The case-records were reviewed of 2122 women aged under 75 years, treated for invasive breast cancer during the time-period 1/1/86-31/12/91 in a geographically defined area. Data were abstracted on operations performed, pathological features, post-operative treatments and details of axillary recurrence. The risk of axillary recurrence was examined by pathological, treatment and patient factors. RESULTS: Axillary recurrence was more than twice as likely after inadequate compared to adequate treatment of the axilla (adequate staging or axillary radiotherapy or clearance). Delayed treatment of the axilla was not as successful as adequate primary treatment: multiple axillary recurrences were twice as common, one third of which were uncontrolled at time of death. Inadequate surgical treatment was associated with increased rates of recurrence despite endocrine therapy, chemotherapy or radiotherapy. Lymphoedema was twice as common if axillary radiotherapy was combined with any axillary surgical procedure. CONCLUSIONS: Axillary recurrence is more common in tumours with adverse pathology but may also result from inadequate axillary treatment. In order to minimise axillary recurrence, optimal treatment of the axilla entails adequate staging (sampling of four or more nodes) and treatment (axillary clearance or radiotherapy and endocrine therapy) in all women.  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