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   53977篇
  免费   3986篇
  国内免费   213篇
耳鼻咽喉   520篇
儿科学   1737篇
妇产科学   1381篇
基础医学   7550篇
口腔科学   906篇
临床医学   5627篇
内科学   11335篇
皮肤病学   1103篇
神经病学   6167篇
特种医学   1270篇
外科学   5200篇
综合类   433篇
一般理论   59篇
预防医学   6308篇
眼科学   868篇
药学   3500篇
中国医学   125篇
肿瘤学   4087篇
  2024年   65篇
  2023年   693篇
  2022年   1194篇
  2021年   2402篇
  2020年   1449篇
  2019年   2002篇
  2018年   2307篇
  2017年   1544篇
  2016年   1688篇
  2015年   1859篇
  2014年   2282篇
  2013年   2982篇
  2012年   4693篇
  2011年   4650篇
  2010年   2413篇
  2009年   2086篇
  2008年   3315篇
  2007年   3326篇
  2006年   3115篇
  2005年   2907篇
  2004年   2571篇
  2003年   2310篇
  2002年   1951篇
  2001年   389篇
  2000年   372篇
  1999年   382篇
  1998年   404篇
  1997年   304篇
  1996年   234篇
  1995年   199篇
  1994年   159篇
  1993年   146篇
  1992年   196篇
  1991年   174篇
  1990年   153篇
  1989年   133篇
  1988年   121篇
  1987年   88篇
  1986年   103篇
  1985年   98篇
  1984年   84篇
  1983年   77篇
  1982年   59篇
  1981年   62篇
  1980年   45篇
  1979年   50篇
  1978年   47篇
  1977年   31篇
  1976年   26篇
  1974年   25篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Acute administration of neuroleptic drugs alters the extracellular level of ascorbate in the neostriatum, and increasing evidence suggests a role for this vitamin in the behavioral, and possibly therapeutic, effects of these drugs. To shed further light on this issue, extracellular ascorbate was recorded in the neostriatum and nucleus accumbens of awake, behaving rats following chronic treatment with either classical (haloperidol) or atypical (clozapine) neuroleptics or ascorbate itself. Electrochemically modified, carbon-fiber microelectrodes were lowered in place the day after the last of 21 daily injections of either haloperidol (0.5 mg/kg, SC), clozapine (20 mg/kg, IP), sodium ascorbate (500 mg/kg, IP) or vehicle. Voltammetric measurements were obtained during quiet rest and following administration ofd-amphetamine (2.5 mg/kg). Repeated treatment with either haloperidol or ascorbate elevated basal extracellular ascorbate and potentiated the amphetamine-induced increase in ascorbate release in neostriatum but not nucleus accumbens. Both treatment groups also showed a significant increase in amphetamine-induced sniffing and repetitive head movements compared to vehicle-treated animals. In contrast, repeated clozapine had no effect on extracellular ascorbate in either neostriatum or nucleus accumbens, but increased the locomotor response to an amphetamine challenge. Thus, to the extent that increases in neostriatal ascorbate exert neuroleptic-like effects, such effects are likely to parallel haloperidol rather than clozapine.  相似文献   
92.
93.
For the past 10 years the alfa-hydroxyacids and the bovine collagen injection have been used for peeling and the correction of multiple skin diseases. Until now, such progressive achievement has occurred in separate parallels just like the indications that have been held distinct. However, the studies carried out in order to clarify the mechanical action of the two substances have shown a common and fundamental denominator: the stimulation of synthesis of the new collagen in the patient's skin. On the basis of these results and the existence of common clinical indications of the use of glycolic acid and collagen, the authors have worked out a protocol involving a combined and contemporary application in progressive steps. They developed the rationales of such protocol and analyzed the results of its application on a number of carefully selected patients for a clinical comparison and on a sample of rats for a histological comparison. They have concluded that the contemporary use of glycolic acid and bovine collagen is a simple and safe method whose synergy action leads to more intense and long-lasting effects than the ones observed in the isolated application of the two substances. The authors have also obtained interesting and significant histological results.  相似文献   
94.
95.
96.
Objectives: The authors reviewed the evidence on performance improvement methods for increasing emergency department (ED) patient satisfaction to provide evidence-based suggestions for clinical practice.
Methods: Data sources consisted of searches through MEDLINE, CINAHL, PSYCHINFO, Cochrane Library, and Emergency Medicine Abstracts and a manual search of references. Articles were included if they reported a performance improvement intervention targeting patient satisfaction in the ED setting. Articles on studies not conducted in the United States or that failed to provide enough details to allow critical evaluation of the study were excluded. Two authors used structured evaluation criteria to independently review each retained study.
Results: Nineteen articles met all selection criteria. Three studies found varying levels of support for multicomponent interventions, predominantly focused on implementation of clinical practice guidelines for specific presenting complaints and process redesign. Sixteen studies evaluated single-component interventions, with the following having at least one supportive study: using alternating patient assignment to provider teams rather than "zone"-based assignment, enhancing provider communication and customer service skills, incorporating information delivery interventions (e.g., pamphlets, video) that target patient expectations, using preformatted charts, and establishing ED-based observation units for specific conditions such as asthma and chest pain.
Conclusions: There is modest evidence supporting a range of performance improvement interventions for improving ED patient satisfaction. Further work is needed before specific, evidence-based recommendations can be made regarding which process changes are most effective. Recommendations are made for improving the quality of performance improvement efforts in the ED setting.  相似文献   
97.
98.
99.
100.
Local treatment options for ductal carcinoma in situ (DCIS) are virtually identical to those for early invasive breast cancer, despite the fact that the survival from this condition is much higher. Our ability to more appropriately tailor therapy for DCIS is hampered by a lack of understanding of the natural history of DCIS, our limited ability to predict the rate of progression to invasive cancer and the response to therapy, and the absence of tools to follow patients who have not had invasive treatments. Neoadjuvant therapy, which has been proven to be both safe and effective in tailoring treatments for invasive cancer, could be ideally suited to DCIS. However, neoadjuvant therapy requires that doctors and patients delay surgical treatment that has known benefits. In order to successfully introduce this approach into clinical practice, risk assessment and decision support tools will be needed to help physicians and patients feel comfortable that they are not being exposed to unnecessary or excessive risk. In addition, we need better imaging to track extent and progression of disease. Among the possible benefits of the neoadjuvant approach, we may discover that many lesions are responsive and some even reversible, leaving us with treatments that might be tailored to biology and with important clues for breast cancer prevention in high-risk 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