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   180292篇
  免费   12284篇
  国内免费   3771篇
耳鼻咽喉   2692篇
儿科学   2709篇
妇产科学   2867篇
基础医学   26721篇
口腔科学   3930篇
临床医学   18199篇
内科学   31469篇
皮肤病学   5173篇
神经病学   13482篇
特种医学   9173篇
外国民族医学   21篇
外科学   22398篇
综合类   7245篇
现状与发展   14篇
一般理论   33篇
预防医学   10296篇
眼科学   4587篇
药学   16857篇
  38篇
中国医学   3910篇
肿瘤学   14533篇
  2024年   213篇
  2023年   1670篇
  2022年   4522篇
  2021年   6788篇
  2020年   3797篇
  2019年   4651篇
  2018年   5543篇
  2017年   4568篇
  2016年   5463篇
  2015年   7688篇
  2014年   9201篇
  2013年   10362篇
  2012年   15202篇
  2011年   15019篇
  2010年   8867篇
  2009年   7382篇
  2008年   10443篇
  2007年   10020篇
  2006年   9226篇
  2005年   8737篇
  2004年   7275篇
  2003年   6449篇
  2002年   5545篇
  2001年   4391篇
  2000年   4107篇
  1999年   3314篇
  1998年   1575篇
  1997年   1253篇
  1996年   989篇
  1995年   899篇
  1994年   784篇
  1993年   614篇
  1992年   1217篇
  1991年   1137篇
  1990年   987篇
  1989年   820篇
  1988年   738篇
  1987年   696篇
  1986年   523篇
  1985年   532篇
  1984年   378篇
  1983年   271篇
  1982年   184篇
  1981年   223篇
  1980年   168篇
  1979年   284篇
  1978年   202篇
  1976年   161篇
  1974年   169篇
  1973年   155篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Objective: To study the biomechanical mechanism of head injuries beaten with sticks, which is common in the battery or assaultive cases. Methods: In this study, the Hybrid-III anthropomorphic test device and finite element model (FEM) of the total human model for safety (THUMS) head were used to determine the biomechanical response of head while being beaten with different sticks. Total eight Hybrid-III tests and four finite element simulations were conducted. The contact force, resultant acceleration of head center of gravity, intracranial pressure and von Mises stress were calculated to determine the different biomechanical behavior of head with beaten by different sticks. Results: In Hybrid-III tests, the stick in each group demonstrated the similar kinematic behavior under the same loading condition. The peak values of the resultant acceleration for thick iron stick group, thin iron stick group, thick wooden stick group and thin wooden stick group were 203.4 g, 221.1 g, 170.5 g and 122.2 g respectively. In finite element simulations, positive intracranial pressure was initially observed in the frontal comparing with negative intracranial pressure in the contra-coup site. Subsequently the intracranial pressure in the coup site was decreasing toward negative value while the contra-coup intracranial pressure increasing toward positive values. Conclusions: The results illustrated that the stiffer and larger the stick was, the higher the von Mises stress, contact force and intracranial pressure were. We believed that the results in the Hybrid-III tests and THUMS head simulations for brain injury beaten with sticks could be reliable and useful for better understanding the injury mechanism.  相似文献   
62.
63.
64.
65.
66.
Sometimes the clinical differentiation between verruca plana (VP) and VP‐like seborrheic keratosis (SK) could be challenged. However, there have been no studies on this issue to date. The aim of this study was to elucidate clinical and dermoscopic differences between these two diseases, and also to suggest a diagnostic algorithm of VP and VP‐like SK without skin biopsy. The patients who had lesions clinically considered as VP or VP‐like SK were the target of our study. We took clinical and dermoscopic photos with informed consent and conducted a questionnaire. All patients had their diagnoses confirmed by biopsy. Thirty‐three patients were enrolled in our study. Seventeen patients were finally diagnosed with VP (51.5%) and 16 patients with VP‐like SK (48.5%). In clinical findings, VP‐like SK showed significantly more scattered distribution than VP (P = 0.039), which exhibited more clustered or grouped distribution (P = 0.039). In dermoscopic findings, brain‐like appearance was more commonly observed in VP‐like SK (P = 0.003) whereas VP showed more red dots or globular vessels (P = 0.017) and even‐colored light brown to yellow patch (P < 0.001). Sex, onset age, the size of each lesion, location, color and shape showed no significant differences between them (P > 0.05). Based on our results, we suggest a diagnostic algorithm using Koebner's phenomenon, dermoscopic findings, distribution of each lesion and biopsy for multiple VP‐like lesions in adults, and we think it will be a very useful diagnostic tool in daily clinical dermatological practice.  相似文献   
67.
68.
Russell-Silver syndrome (RSS) is a congenital disease characterized by short stature due to growth hormone deficiency, physical asymmetry, inverted triangular face, micrognathia, prominent forehead, and hypodontia. This case report presents a prosthetic management of a 6-year-old patient with Russell-Silver syndrome treated with overdentures on the maxilla and the mandible using the remaining primary teeth. Subsequent and comprehensive dental management considering the growth and development of a young patient will be necessary.  相似文献   
69.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery.  相似文献   
70.
The growth of online support groups has led to an expression effects paradigm within the health communication literature. Although religious support expression is characterized as a typical subdimension of emotional support, we argue that in the context of a life-threatening illness, the inclusion of a religious component creates a unique communication process. Using data from an online group for women with breast cancer, we test a theoretical expression effects model. Results demonstrate that for breast cancer patients, religious support expression has distinct effects from general emotional support messages, which highlights the need to further theorize expression effects along these lines.  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