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   22488篇
  免费   2134篇
  国内免费   45篇
耳鼻咽喉   194篇
儿科学   859篇
妇产科学   494篇
基础医学   2918篇
口腔科学   458篇
临床医学   2477篇
内科学   4619篇
皮肤病学   174篇
神经病学   2125篇
特种医学   839篇
外科学   3144篇
综合类   509篇
一般理论   12篇
预防医学   2447篇
眼科学   460篇
药学   1519篇
中国医学   26篇
肿瘤学   1393篇
  2022年   142篇
  2021年   365篇
  2020年   203篇
  2019年   399篇
  2018年   392篇
  2017年   262篇
  2016年   321篇
  2015年   349篇
  2014年   582篇
  2013年   875篇
  2012年   1213篇
  2011年   1228篇
  2010年   698篇
  2009年   621篇
  2008年   1145篇
  2007年   1233篇
  2006年   1162篇
  2005年   1126篇
  2004年   1105篇
  2003年   1078篇
  2002年   1067篇
  2001年   494篇
  2000年   512篇
  1999年   461篇
  1998年   295篇
  1997年   244篇
  1996年   259篇
  1995年   244篇
  1994年   251篇
  1993年   224篇
  1992年   373篇
  1991年   304篇
  1990年   340篇
  1989年   350篇
  1988年   289篇
  1987年   301篇
  1986年   321篇
  1985年   289篇
  1984年   261篇
  1983年   246篇
  1982年   191篇
  1981年   205篇
  1980年   161篇
  1979年   219篇
  1978年   188篇
  1977年   130篇
  1976年   151篇
  1975年   144篇
  1974年   148篇
  1973年   146篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
111.
Flexor digitorum profundus avulsions, are well-documented injuries occasionally associated with a distal phalanx fragment. While the injury may involve primarily either tendon or bone, a rarely observed variant combines both tendon and bone avulsions. A type IV variant seen after two sequential injuries is described.  相似文献   
112.
Twelve patients with metastatic colon cancer were treated with 131I-chimeric B72.3 (IgG-4) at total doses of 28 or 36 mCi/m2 in two or three weekly fractions. Bone marrow suppression was the only significant side effect. The degree of bone marrow suppression adjusted for whole-body dose was modestly but statistically significantly (p = 0.04) less than that seen with identical doses given as a single infusion for the total dose of 36 mCi/m2. Nine of twelve patients developed an antibody response to ch B72.3, which altered the kinetics of radiolabeled antibody in four patients given a second course of therapy. One patient had a minor response that lasted 4 mo. Fractionation of this particular radiolabeled antibody at the dose schedule used produced a modest increase in the therapeutic window in regard to administered dose.  相似文献   
113.
Monocular oscillatory-motion visual evoked potentials (VEPs) were measured in prospective and retrospective groups of infantile esotropia patients who had been aligned surgically at different ages. A nasalward-temporal response bias that is present prior to surgery was reduced below pre-surgery levels in the prospective group. Patients in the retrospective group who had been aligned before 2 yr of age showed lower levels of response asymmetry than those who were aligned after age 2. The data imply that binocular motion processing mechanisms in infantile esotropia patients are capable of some degree of recovery, and that this plasticity is restricted to a critical period of visual development.  相似文献   
114.
A 71-year-old man presented with left hydronephrosis 1 year after aortofemoral bypass. Hydronephrosis was due to extrinsic compression of the ureter between the graft anteriorly and the native iliac artery. Treatment by endoscopic transluminal balloon dilation resulted in complete resolution of the hydronephrosis.  相似文献   
115.
A captopril renal study performed with both radiohippuran and 99mTc-MAG3 demonstrated the typical changes of a hemodynamically significant renal artery stenosis in a hypertensive renal allograft recipient. Arteriography demonstrated high grade stenosis not of the renal artery but of the iliac artery. After successful angioplasty, the patient's hypertension resolved.  相似文献   
116.
Periosteal bone turnover is poorly understood. We documented intramembranous periosteal bone turnover in the femoral neck in intact nonhuman primates and an increase in osteoclast numbers at the periosteal surface in sex steroid-deficient animals. Our studies are the first to systematically document periosteal turnover at the femoral neck. INTRODUCTION: Bone size is an important determinant of bone strength, and cellular events at the periosteal surface could alter bone dimensions. We characterized periosteal cellular activity with dynamic histomorphometric studies of nonhuman primate femoral neck and shaft. MATERIALS AND METHODS: Femur specimens from 16 intact adult male and female nonhuman primates (Rhesus [Macaca mulatta, n = 9] and Japanese Macaque [Macaca fuscata, n = 7]) were analyzed. Animals were double-labeled with tetracycline, and necropsy was performed 2-7 days after the last dose. We characterized periosteal resorptive activity in an additional group of five intact and four castrate female animals. Multiple group comparisons in intact animals were performed by one-way ANOVA followed by a Fisher PLSD posthoc test. In gonadectomized animals, Fisher's exact test was used for dichotomous and Mann-Whitney U-test for continuous variables. RESULTS: Bone turnover in the periosteum of the femoral neck in intact animals was more rapid than at the femoral shaft but slower than in femoral neck cancellous bone. Similarly, in these intact animals, the eroded surface of cortical bone at the femoral neck periosteal surface was significantly greater than in the cancellous bone compartment (p < 0.0001) or on the femoral shaft (p < 0.0001). Gonadectomized female animals showed an increase in osteoclast number on the periosteal surface compared with intact controls (p < 0.01). CONCLUSIONS: We documented intramembranous periosteal bone turnover in the femoral neck by histomorphometric analyses. The tissue level bone formation rate was sufficient to add substantively to femoral neck size over time. Periosteal osteoclastic activity was not the result of the emergence of intracortical tunneling at the bone surface. Sex steroid deficiency produced an increase in osteoclast numbers at the periosteal surface. This is the first systematic documentation of periosteal turnover at the femoral neck.  相似文献   
117.
Summary:  Naturally occurring mutants and genetically manipulated strains of mice are widely used to model a variety of human diseases. Atlases are an invaluable aid in understanding the impact of such manipulations by providing a standard for comparison and to facilitate the integration of anatomic, genetic, and physiologic observations from multiple subjects and experiments. We have developed digital atlases of the C57BL/6J mouse brain (adult and neonate) as comprehensive frameworks for storing and accessing the myriad types of information about the mouse brain. Along with raw and annotated images, these contain database management systems and a set of tools for comparing information from different techniques and different animals. Each atlas establishes a canonical representation of the mouse brain and provides the tools for the manipulation and analysis of new data. We describe both these atlases and discuss how they may be put to use in organizing and analyzing data from mouse models of epilepsy.  相似文献   
118.
119.
This investigation has been conducted as two separate studies. Part I consisted of the determination of the prothrombin activity in normal newborn infants together with observations on the alterations in this activity which result from the administration of vitamin K to the mother. Part II was concerned with the practical application of the knowledge gained from the first study. It aimed to show the value of intra-partum vitamin K administration in reducing the incidence of hemorrhage in newborn infants.  相似文献   
120.

Background  

This study explored the feasibility of using an Internet survey of people with fibromyalgia (FM), with a view to providing information on demographics, sources of information, symptoms, functionality, perceived aggravating factors, perceived triggering events, health care utilization, management strategies, and medication use.  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