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   9860篇
  免费   777篇
  国内免费   118篇
耳鼻咽喉   204篇
儿科学   328篇
妇产科学   215篇
基础医学   1172篇
口腔科学   214篇
临床医学   930篇
内科学   1790篇
皮肤病学   208篇
神经病学   1046篇
特种医学   689篇
外科学   1295篇
综合类   217篇
一般理论   7篇
预防医学   927篇
眼科学   479篇
药学   526篇
中国医学   3篇
肿瘤学   505篇
  2021年   157篇
  2019年   106篇
  2018年   126篇
  2017年   84篇
  2016年   103篇
  2015年   129篇
  2014年   208篇
  2013年   295篇
  2012年   404篇
  2011年   409篇
  2010年   260篇
  2009年   260篇
  2008年   390篇
  2007年   432篇
  2006年   373篇
  2005年   414篇
  2004年   425篇
  2003年   367篇
  2002年   337篇
  2001年   322篇
  2000年   303篇
  1999年   322篇
  1998年   136篇
  1997年   129篇
  1996年   139篇
  1995年   137篇
  1994年   123篇
  1993年   126篇
  1992年   200篇
  1991年   205篇
  1990年   220篇
  1989年   188篇
  1988年   194篇
  1987年   221篇
  1986年   190篇
  1985年   226篇
  1984年   136篇
  1983年   109篇
  1982年   93篇
  1981年   102篇
  1980年   96篇
  1979年   119篇
  1978年   120篇
  1977年   97篇
  1976年   91篇
  1975年   89篇
  1974年   97篇
  1973年   96篇
  1972年   82篇
  1970年   87篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
22.
Nocturnal symptoms are common and often disabling in asthmatic subjects. Furthermore, they often persist, in spite of appropriate dosages of inhaled beta 2-agonists and topical steroids. In such a clinical situation, theophylline preparations may have a therapeutic role. This double-blind, placebo-controlled, cross-over trial was designed to evaluate the effectiveness of a twice-daily Bioavail slow-release theophylline capsule in a group of out-patient asthmatics, with a history of nocturnal and/or early morning wheeze or chest tightness. Theophylline was initially prescribed and monitored in an 'open' phase to obtain the drug dosage required to achieve a serum level in the therapeutic range of 10-20 mg/l. In the ten patients who completed the study, serum theophylline levels were stable throughout. During active treatment there was an improvement in morning peak expiratory flow rate (PEFR), and a reduction in measurements of diurnal variation. In addition, the bronchodilator response to an inhaled beta 2-agonist was preserved. Bioavail theophylline has thus been shown to be an effective agent in the management of adults with nocturnal asthma.  相似文献   
23.
A multivariate analysis of the relationships between service attributes and physician perceptions was conducted as an approach to marketing substance abuse treatment services. The results of this attribute-perceptive-preference study indicate: the physician(s) on staff attribute makes the greatest contribution to perceived quality and efficiency; easy referral admission makes the largest contribution to accessibility perceptions; and providing feedback produces the greatest contribution to perceived continuity. The JCAH attributes neither adds to nor subtracts from the perceptions of any of the four perceptual attributes. Other findings indicate that perceived efficiency produces the greatest contribution to overall consumer preference. Quality perceptions make the second largest contribution to overall preference, followed by continuity and accessibility perceptions.  相似文献   
24.
Several antimicrobial drugs have been shown to pharmacokinetically interact with cyclosporine. On two separate occasions, we observed increases in cyclosporine plasma concentrations during concomitant miconazole therapy in a heart transplant patient with an infection secondary to Pseudallescheria boydii. To our knowledge, no interaction between cyclosporine and miconazole has previously been reported. In addition, drug interactions were observed between cyclosporine and ketoconazole and possibly between cyclosporine and SCH 39304, an investigational azole-antifungal agent. No interaction was noted between cyclosporine and fluconazole. In general, clinicians should anticipate drug interactions between cyclosporine and azole-antimycotic agents.  相似文献   
25.
To clarify whether the impairment of right-brain-damaged (RBD) patients in face recognition is related to perceptual or mnestic processing stages, we tested unilaterally lesioned patients and controls in a Sternberg-type memory search task. Subjects had to memorize sets of 1, 2, or 3 faces (or, in a control condition, digits) and were then to recognize these memorized stimuli among new ones by speeded choice reactions. In this task, deficits in stimulus encoding and memory search should show up in increased intercepts and slopes, respectively, of the RT function over memory set size. A face-specific impairment of the RBD patient group, consisting in longer reaction times and higher error rates, was confirmed but could not be unequivocally attributed to either stimulus encoding or memory search. However, inspection of individual data suggested that (1) some RBD patients are virtually unimpaired in face recognition and (2) if impairment after right hemisphere damage is present, it may selectively affect either stimulus encoding or memory search.  相似文献   
26.
A retrospective review of 69 patients with testicular seminoma, stage I and II, treated by orchiectomy and adjuvant irradiation at McGill University Hospitals from 1972 to 1987 was performed. All patients underwent either lymphangiogram or computed axial tomography scan for evaluation of retroperitoneal disease. There were 52 stage I (75%), 13 stage IIA (11%), 2 stage IIB (3%), and 2 stage IIC (Royal Marsden Hospital staging criteria). Median follow-up time was 6.2 years. The 10-year actuarial survivals were 94% and 93% for stages I and II, respectively. Only two stage I patients failed treatment, and both died from metastatic disease. Interestingly, both developed biopsy-proven metastatic brain disease and had no evidence of intra-abdominal recurrence. In stage II disease, only one patient failed the treatment. There was no serious acute toxicity and no late complications have been encountered. Radiation therapy following orchiectomy is the treatment of choice for stage I and for most stage II patients with testicular seminoma. The controversial aspects of radiographic retroperitoneal staging, the use of prophylactic mediastinal irradiation for stage II patients, and the role of surveillance only for stage I patients are discussed.  相似文献   
27.
A controlled randomized clinical trial was undertaken to assess the ability of combined non-specific and specific immunotherapy to alter the disease-free interval and overall survival of patients with Stage B or C large bowel cancer. The immunotherapy consisted of a 2 year programme of vaccinations with BCG and neuraminidase-treated autologous tumour cells. Three hundred and one patients entered the trial. At 5 years of follow-up there is no evidence that this form of immunotherapy can alter either the disease-free interval or survival in this group of patients.  相似文献   
28.
When glaucoma medication fails to adequately control intraocular pressure (IOP), a second medication is frequently added. Before adding a second drug to patients whose IOP was no longer controlled by 0.5% timolol, we tested the effect of switching to another beta blocker, levobunolol (0.5 or 1%). We also evaluated the effect of study participation on compliance in the control group continuing to receive 0.5% timolol. In each treatment group, the IOP of approximately 30-40% of the patients was successfully controlled for the 3-month study period. The remaining patients did not exhibit significant pressure reductions and were dropped from the study within 2 weeks. We concluded that (1) the results of 'switch' studies without a control group must be interpreted carefully, and (2) the initiation of a 'new regimen' with an equieffective beta blocker may be sufficient to increase compliance and thereby control IOP.  相似文献   
29.
We report an analysis of the qualitative phase of a study of patients' and carers' views of primary care services, focusing on their experiences of access to face-to-face general practitioner (GP) consultations during the period when new access policies were being implemented. Practices interpreted the new policy in various ways; restricted interpretations, including restriction of access to telephone booking, could cause distress to patients. Patients and carers welcomed flexible interpretations of the policy that offered choice, such as a choice of GP, or of booking in advance.  相似文献   
30.
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