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   3695802篇
  免费   293520篇
  国内免费   17057篇
耳鼻咽喉   51872篇
儿科学   111506篇
妇产科学   97186篇
基础医学   574204篇
口腔科学   103421篇
临床医学   326471篇
内科学   659179篇
皮肤病学   96549篇
神经病学   312157篇
特种医学   145736篇
外国民族医学   535篇
外科学   573895篇
综合类   114881篇
现状与发展   24篇
一般理论   2305篇
预防医学   294224篇
眼科学   86001篇
药学   260675篇
  32篇
中国医学   12213篇
肿瘤学   183313篇
  2021年   55700篇
  2020年   35632篇
  2019年   58593篇
  2018年   71825篇
  2017年   54936篇
  2016年   60806篇
  2015年   75049篇
  2014年   109397篇
  2013年   174496篇
  2012年   96004篇
  2011年   95825篇
  2010年   117474篇
  2009年   122157篇
  2008年   83114篇
  2007年   87632篇
  2006年   97846篇
  2005年   92777篇
  2004年   94526篇
  2003年   85714篇
  2002年   75974篇
  2001年   124959篇
  2000年   118470篇
  1999年   114491篇
  1998年   67398篇
  1997年   64599篇
  1996年   61754篇
  1995年   57134篇
  1994年   51329篇
  1993年   47885篇
  1992年   81083篇
  1991年   76525篇
  1990年   73266篇
  1989年   72456篇
  1988年   67538篇
  1987年   65962篇
  1986年   62831篇
  1985年   62165篇
  1984年   54545篇
  1983年   49112篇
  1982年   43620篇
  1981年   40816篇
  1980年   38584篇
  1979年   46489篇
  1978年   39440篇
  1977年   36147篇
  1976年   32499篇
  1975年   32503篇
  1974年   34508篇
  1973年   33113篇
  1972年   31471篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Introduction Recent reviews found problem gamblers are heterogeneous and recommended subtyping gamblers in treatment studies. Objective Review factors (stage of change, preferred gambling activity, co-occurring disorder, and temporal instability of symptoms) for subtyping by evaluating the evidence for their effects on gambling treatment. Methods Literature review, evidence grading. Results Evidence is limited that any of the reviewed factors affects gambling treatment. Substantial evidence from prospective studies and other evidence from cross-sectional studies and the strong placebo response among pathological gamblers support the temporal instability of gambling symptoms. Conclusions Multiple studies are needed to develop the evidence base needed to subtype gamblers in treatment. Changes in the diagnostic criteria of pathological gambling may be necessary, especially to specify the persistence of gambling-related symptoms.  相似文献   
992.
993.
Abstract The pain of cluster headache attacks is severe, excruciating and selectively responsive to subcutaneous sumatriptan. Serious cardiovascular events attributed to sumatriptan are extremely rare and have most often been reported in patients at significant cardiovascular risk, or in overt cardiovascular disease. They also have occurred, however, in patients without evidence of cardiovascular disease. We describe a 42-year-old man with episodic cluster headache without history of coronary artery disease who was admitted to our coronary care unit for acute myocardial infarction after 3 h of subcutaneous injection of sumatriptan. During hospitalisation cluster headache attacks were successfully treated with e.v. indomethacin.  相似文献   
994.
Over 100 mutations in the presenilin‐1 gene (PSEN1) have been shown to result in familial early onset Alzheimer disease (EOAD), but only a relatively few give rise to plaques with an appearance like cotton wool (CWP) and/or spastic paraparesis (SP). A family with EOAD, seizures and CWP was investigated by neuropathological study and DNA sequencing of the PSEN1 gene. Aβ was identified in leptomeningeal vessels and in cerebral plaques. A single point mutation, p.L420R (g.1508T > G) that gives rise to a missense mutation in the eighth transmembrane (TM8) domain of PS1 was identified in two affected members of the family. p.L420R (g.1508T > G) is the mutation responsible for EOAD, seizures and CWP without SP in this family.  相似文献   
995.
Clinical decisions are often made with incomplete information, yet patient care decisions are made every day. Patients vary clinically, uncertainty exists in diagnostic and prognostic information, and many preventive and treatment alternatives have not been formally assessed for their effectiveness. Because scientific information will never answer all clinical questions, clinical decisions are partially based on probabilistic information.
This paper describes how to apply clinical decision making to diagnosing and managing dental caries and periodontal diseases. By using explicit information to quantify probabilities and outcomes, clinical decision making analyzes decisions made under uncertain conditions and the uncertain impact of clinical information.
Clinical decision making incorporates concepts for preventing, diagnosing and treating dental caries and periodontal diseases: risk assessment, evidence-based dentistry, and multiple oral health outcomes. This information can serve as a tool for clinicians to augment clinical judgment and expertise.  相似文献   
996.
997.
Long-term daily use of gamma-hydroxybutyrate (GHB) and related compounds has recently been associated with a withdrawal syndrome. To the best of the authors' knowledge, there are currently no animal models of GHB withdrawal. OBJECTIVES: The authors studied and described the effect of chronic dosing of GHB (3-6 days) on tolerance and withdrawal in a rat model. METHODS: Rats were administered GHB every three hours via intraperitoneal catheter. Groups of rats (2 per group) were dosed with GHB for either 3 (24 doses), 4 (32 doses), 5 (40 doses), or 6 (48 doses) days. The GHB dose was 0.25 g/kg for doses 1-8, 0.75 g/kg for doses 9-12, 1 g/kg for doses 13-16, 1.25 g/kg for doses 17-24, 1.5 g/kg for doses 25-32, 1.75 g/kg for doses 33-40, and 2 g/kg for doses 41-48. Following the last dose of GHB, the rats were scored using a 16-point ethanol intoxication-withdrawal scale rating spontaneous behaviors, response to handling, grooming, and neurological signs. Lower scores indicate intoxication, while higher scores indicate withdrawal. Scores were recorded at hours 0, 1, 2, 3, 4, 5, 6, 9, 12, and 24. RESULTS: Tolerance: Rats dosed with GHB for more days were less intoxicated one hour after their last GHB dose despite receiving higher doses. WITHDRAWAL: The scores for all rats dosed with GHB increased at hours 4 (p = 0.028), 5 (p = 0.037), 6 (p = 0.007), and 9 (p = 0.024) after the last dose, indicating withdrawal. The scores demonstrated a linear increase dependent upon the number of days of GHB dosing at hours 3 (p < 0.000), 4 (p = 0.004), 5 (p = 0.002), and 12 (p = 0.039) as well as prior to the last dose at hour 0 (p = 0.000). No rats developed seizures. CONCLUSIONS: Tolerance and mild withdrawal in rats can be induced by administering intraperitoneal GHB every three hours for 3-6 days. More prolonged dosing and higher doses of GHB may be necessary to induce severe withdrawal.  相似文献   
998.
999.
1000.
Adamantinoma of long bones is one of the rarest of malignant bone tumors; it is commonly located in the middle or lower third of the diaphysis of the tibia. A case with multiple occurrences affecting both the tibia and fibula is presented. En bloc resection with wide operative margins was performed, and a large tibial defect of 23 cm was effectively bridged by a revascularized free fibular flap. At 13 months follow-up, there was no sign of local recurrence or metastasis, and the patient was mobile.  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