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   5856篇
  免费   453篇
  国内免费   10篇
耳鼻咽喉   60篇
儿科学   170篇
妇产科学   215篇
基础医学   752篇
口腔科学   297篇
临床医学   611篇
内科学   1014篇
皮肤病学   91篇
神经病学   514篇
特种医学   277篇
外科学   620篇
综合类   64篇
一般理论   1篇
预防医学   543篇
眼科学   120篇
药学   540篇
中国医学   3篇
肿瘤学   427篇
  2022年   47篇
  2021年   79篇
  2020年   51篇
  2019年   84篇
  2018年   87篇
  2017年   90篇
  2016年   86篇
  2015年   104篇
  2014年   132篇
  2013年   188篇
  2012年   260篇
  2011年   287篇
  2010年   176篇
  2009年   133篇
  2008年   276篇
  2007年   285篇
  2006年   267篇
  2005年   267篇
  2004年   226篇
  2003年   269篇
  2002年   244篇
  2001年   180篇
  2000年   161篇
  1999年   189篇
  1998年   61篇
  1997年   40篇
  1996年   50篇
  1995年   42篇
  1994年   57篇
  1992年   105篇
  1991年   110篇
  1990年   99篇
  1989年   113篇
  1988年   103篇
  1987年   109篇
  1986年   106篇
  1985年   105篇
  1984年   63篇
  1983年   66篇
  1982年   59篇
  1979年   66篇
  1978年   62篇
  1977年   49篇
  1976年   55篇
  1975年   52篇
  1974年   48篇
  1973年   43篇
  1972年   43篇
  1971年   42篇
  1970年   40篇
排序方式: 共有6319条查询结果,搜索用时 10 毫秒
61.
Under Medicare's Part B program, wide variations are found in average reimbursements for physicians' services by demographic and geographic characteristics of the beneficiaries. Average reimbursements per beneficiary enrolled in the program depend upon the percentage of enrolled persons who exceed the deductible and receive reimbursements, the average allowed charge per service, and the number of services used. This study analyzes differences in average reimbursements per beneficiary for physicians' services in 1975 and discusses allowed charges and use factors that affect average reimbursements. Differences in the level of allowed charges and their impact on meeting the annual deductible are also discussed. The study indicates that average reimbursements per beneficiary are likely to continue to vary significantly year after year under the present Part B cost-sharing and reimbursement mechanisms.  相似文献   
62.
A Vincent  J Newsom-Davis  P Newton  N Beck 《Neurology》1983,33(10):1276-1282
We studied serum anti-acetylcholine receptor (AChR) antibody and clinical response to thymectomy in myasthenia gravis for 1 to 3 1/2 years postoperatively in 25 patients who did not receive immunosuppressive drugs. Clinical grade was assessed "blind." Mean final anti-AChR values were significantly reduced compared with thymectomy values (69.6 +/- 7.5% SEM; p less than 0.05). Anti-AChR fell steadily to 42-15% in the six patients who developed remission. Overall, there was a significant correlation between changes in anti-AChR and in clinical grade at 1 year (p less than 0.01) and at final assessment (p less than 0.001). An association between fall in anti-AChR and clinical improvement was absent in five individuals and not accounted for by change in antibody characteristics.  相似文献   
63.
It seems timely and pertinent to review the long-term follow-up of four patients who were deliberately exposed before transplant to donor antigens in an "enhancement" protocol. Not only were there no adverse effects observed, but three of the four patients never had an identifiable rejection episode. One of the successful allograft recipients had cytotoxic antibodies to his donor's cells. These appear to have been cold, T- and B-cell-reactive antibodies of doubtful significance. Both long-term surviving recipients showed weakness in degree of mitogenesis in mixed culture of donor and recipient peripheral blood mononuclear cells, which does not appear to be related to a macrophage defect but may be related to a lack of active rosette-forming T cells.  相似文献   
64.
The first step in the investigation of infertile men is to obtain 2 seminal analyses 3 days after the previous ejaculation. Clinical assessment of testicular size is an unreliable means of assessing spermatogenesis and is best done by performing bilateral testicular biopsies. Azoospermic men with grossly elevated FSH levels should be advised to consider AID or adoption. Those with normal or mildly elevated FSH levels should undergo testicular exploration in an attempt to correct an obstructive lesion. Azoospermic men with subnormal FSH levels may have an isolated hormone defect which will respond to treatment with Pergonal. Different treatment programmes for oligozoospermic men depending on the results of the FSH and LH assays may lead to a more rational approach to therapy. Infertility associated with varicocele may possibly be associated with a local disturbance of "inhibin" and FSH concentrations.  相似文献   
65.
OBJECTIVE: The closure of a long-stay psychiatric hospital in Sydney caused the transfer of an initial 40 very long-term patients to four community residences, each with 10 beds, for a continuing process of deinstitutionalisation. Community psychiatric service support and 24-h supervision were provided. This paper describes the residents' clinical progress which was assessed over a 2-year period. METHOD: This study employed a quasi-experimental longitudinal design. Evaluation commenced prior to discharge and continued for 2 years following community relocation using the Brief Psychiatric Rating Scale, Life Skills Profile, Social Behaviour Scale, Montgomery Asberg Depression Rating Scale and Quality Of Life measures. Readmission, demographic, case history and medication data were also collected. RESULTS: Of the 40 patients initially transferred to the community, seven required long-term readmission to hospital (either prior to or after amalgamation) and one patient died of medical causes. Additional patients transferred from the hospital to the community following the readmissions. Three of these additional patients had achieved a 2-year community tenure during the study period and were included in the clinical evaluation. The 35 residents in total who remained in the community for 2 years, demonstrated a significant improvement in psychotic symptoms, without significant change in the level of neuroleptic medication. Importantly, the 2 years of community living resulted in a significant increase in the residents' life satisfaction. There were no statistically significant changes in residents' living skills, depressive symptoms or social behaviour problems over the 2 years, indicative of the need for supervision and community service support following deinstitutionalisation. Over the 2-year period, some 37% of the residents required temporary readmission. CONCLUSION: This study demonstrates the clinical effectiveness of deinstitutionalisation, when planned within a mental health system with adequate community resources.  相似文献   
66.
Cerebral malaria may be the most common non-traumatic encephalopathy in the world. The pathogenesis is heterogeneous and the neurological complications are often part of a multisystem dysfunction. The clinical presentation and pathophysiology differs between adults and children. Recent studies have elucidated the molecular mechanisms of pathogenesis and raised possible interventions. Antimalarial drugs, however, remain the only intervention that unequivocally affects outcome, although increasing resistance to the established antimalarial drugs is of grave concern. Artemisinin derivatives have made an impact on treatment, but other drugs may be required. With appropriate antimalarial drugs, the prognosis of cerebral malaria often depends on the management of other complications-for example, renal failure and acidosis. Neurological sequelae are increasingly recognised, but further research on the pathogenesis of coma and neurological damage is required to develop other ancillary treatments.  相似文献   
67.
68.
OBJECTIVE: The Food and Drug Administration (USA) approved the transurethral administration of prostaglandin (alprostadil in January 1997), which had an efficacy of approximately 50% in clinical trials. We studied its effectiveness in clinical practice. METHODS: Patient and partner education was followed by an initial office trial of a medicated urethral system for erection (MUSE) after other medical risk factors were corrected during a 2- to 4-month period. The initial titration dose of alprostadil was usually 125 or 250 microg. Further titration, if needed, was instituted by the patient at home. Success was determined as the satisfactory completion of sexual intercourse in more than 66% of attempts, with a minimum of two being required. RESULTS: Two hundred and seventy patients entered the trials, and follow-up information was available in 229 (85%). The overall success rate was 56%. The dose required was 500 microg in 49.2% and 1,000 microg in 42.2%. Of the 44% in whom treatment failed, 61.4% did so because of lack of efficacy and 38.6% because of side effects (genital pain or urethral bleeding). Minor urogenital symptoms, which did not interfere with treatment, occurred in an additional 40% of patients. CONCLUSIONS: The efficacy of transurethral administration of alprostadil (56%) is higher than the initial published clinical trial data and higher than recent reported clinical experiences, although higher doses were required in our study. Men over 50 years of age, having an organic cause for erectile dysfunction, had better responses. Patient and partner education is important for successful treatment, and the in-office initial titration is an integral part of this success. Prior correction of medical risk factors may enhance the success rate.  相似文献   
69.
70.
Molecular mechanisms of glucocorticoid action: what is important?   总被引:23,自引:0,他引:23       下载免费PDF全文
Newton R 《Thorax》2000,55(7):603-613
  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