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   32264篇
  免费   1896篇
  国内免费   71篇
耳鼻咽喉   285篇
儿科学   733篇
妇产科学   599篇
基础医学   4354篇
口腔科学   698篇
临床医学   3078篇
内科学   6290篇
皮肤病学   513篇
神经病学   3442篇
特种医学   1252篇
外国民族医学   55篇
外科学   4711篇
综合类   441篇
一般理论   15篇
预防医学   2701篇
眼科学   872篇
药学   2094篇
  1篇
中国医学   33篇
肿瘤学   2064篇
  2022年   218篇
  2021年   439篇
  2020年   281篇
  2019年   449篇
  2018年   511篇
  2017年   387篇
  2016年   437篇
  2015年   585篇
  2014年   797篇
  2013年   1179篇
  2012年   1710篇
  2011年   1802篇
  2010年   981篇
  2009年   924篇
  2008年   1711篇
  2007年   1831篇
  2006年   1761篇
  2005年   1808篇
  2004年   1729篇
  2003年   1612篇
  2002年   1582篇
  2001年   575篇
  2000年   522篇
  1999年   489篇
  1998年   364篇
  1997年   335篇
  1996年   295篇
  1995年   288篇
  1994年   243篇
  1993年   255篇
  1992年   355篇
  1991年   328篇
  1990年   271篇
  1989年   286篇
  1988年   288篇
  1987年   289篇
  1986年   267篇
  1985年   249篇
  1984年   292篇
  1983年   232篇
  1982年   268篇
  1981年   239篇
  1980年   221篇
  1979年   210篇
  1978年   192篇
  1977年   148篇
  1976年   175篇
  1975年   167篇
  1974年   196篇
  1973年   151篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
Composite resin has proven to be a predictable and reliable restorative material for the treatment of traumatized dentin or dental caries in the anterior region. Ongoing material advancements continue to contribute to favorable results in the treatment of the contemporary patient. In using a resin material, it is important for the dental professional to establish an appropriate clinical approach that will protect healthy tissues, while meeting the patient's expectations. This article presents a series of cases that encompass the clinical and aesthetic possibilities provided by modern composites. LEARNING OBJECTIVES: This article depicts the potential clinical and aesthetic results that can be achieved using contemporary composite resins. Upon reading this article, the reader should: 1) Understand operative techniques for obtaining aesthetic results in the anterior maxilla. 2) Become familiar with the importance of formulating a treatment strategy that combines minimum chairtime with a high-quality, aesthetic result.  相似文献   
83.
84.
We report a case of refractory bladder fistula in a diabetic renal allograft recipient that recurred shortly after conventional operative repair without any detectable external cause. After reoperation and use of a vascularized rectus muscle flap the fistula closed and the patient has retained excellent graft function. It is suggested that this technique should be considered as the primary repair modality for bladder fistulas in diabetic recipients, when wound healing is impaired seriously as a consequence of the combined effects of diabetic microangiopathy and steroid therapy.  相似文献   
85.
86.
Neurotrophic factors have been demonstrated to prevent the development of peripheral neuropathy in animal models, but the therapeutic use of these factors in human disease has been limited by the short serum half-life and dose-limiting side effects of these potent peptides. We used peripheral subcutaneous inoculation with a replication-incompetent, genomic herpes simplex virus-based vector containing the coding sequence for neurotrophin-3 to transduce sensory neurons of the rat dorsal root ganglion in vivo, and found that expression of neurotrophin-3 from the vector protected peripheral sensory axons from neuropathy induced by intoxication with pyridoxine assessed by electrophysiological (foot sensory response amplitude, and conduction velocity, and H-wave), histological (nerve morphology and morphometry), and behavioral measures of proprioceptive function. In vivo gene transfer using herpes simplex virus vectors provides a unique option for treatment of diseases of the sensory peripheral nervous system.  相似文献   
87.
Intracranial self-stimulation (ICSS) was assessed from the prefrontal cortex in CD-1 mice immediately (0 h), 24 h and 168 h following exposure to uncontrollable footshock. Marked reductions in ICSS rates were observed in all mice immediately following the stressor. Although the ICSS alterations were transient in some animals, ICSS rates were reduced in the majority of animals 24-h and 168-h poststressor. Mice of either the shock or no shock treatment groups were administered either saline or desmethylimipramine (DMI, 5 mg/kg x 2) for 20 consecutive days. Chronic DMI ameliorated the stressor-induced ICSS deficits from the prefrontal cortex. Potential explanations for the stressor-provoked variations in ICSS and the effects of DMI are discussed.  相似文献   
88.
As clinical experience with patients with ZES has grown, increasing recognition has been made of the broad spectrum of symptoms associated with gastrinomas. Diarrhea and acid-induced esophageal injury have taken their place alongside chronic peptic ulcer disease as indications for screening for gastrinoma. Diagnostic testing should begin with fasting serum gastrin levels and should include intravenous secretin infusion if fasting serum levels of gastrin are nondiagnostic and the patient is not found to be hypochlorhydric. Tumor localization is critical to aid in the identification of patients with potentially curable localized disease. Preoperative evaluation utilizing CT scanning with intravenous contrast should be done early and should be supplemented by other imaging modalities as necessary. Exploratory laparotomy, including a thorough examination of the duodenum and perhaps intraoperative ultrasound, should be performed in all patients with sporadic gastrinoma who lack evidence of extensive metastatic disease on preoperative evaluation. By utilizing this approach, it is likely that at least 20% of patients with ZES can be cured. With the availability of the highly effective H(+)-K(+)-ATPase inhibitor omeprazole, excellent control of symptoms related to gastric acid hypersecretion can be expected. Patients with unresectable gastrinoma may thus avoid potentially morbid antisecretory surgery and be managed with a fairly simple medical regimen. Further developments in the chemotherapeutic management of these patients with unresectable disease should be forthcoming in the future.  相似文献   
89.
90.
The classification of breast parenchymal patterns (N1, P1, P2, DY) and the percentage of the breast containing radiographic densities are two highly correlated radiographic measures proposed as predictors of the risk of breast cancer. In this case-control study, 160 cases of breast cancer and 160 matched controls from a mammography referral practice were compared to determine the risk of breast cancer associated with each of these two radiographic measures. The mammographic densities were quantified on caudal projections by means of a compensating polar planimeter. A relative risk estimate of 3.3 (p less than .05) was associated with the P2 + DY patterns compared with the N1 + P1 patterns. Significantly elevated risks of 4.3 to 5.5 also were observed among women whose breasts contained at least 25% mammographic densities, compared with women with less than 25% involvement. These radiographic measures tended to be more predictive of the risk of breast cancer in black women than in white women. Although the precise clinical roles of breast parenchymal patterns and densities have not been defined fully, the results of this study suggest that they are useful in the recognition of women at high risk of breast cancer. We make no claims that the findings of this study are sufficiently developed to be used as a basis for screening strategies.  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