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   181315篇
  免费   1380篇
  国内免费   25篇
耳鼻咽喉   1253篇
儿科学   6796篇
妇产科学   3166篇
基础医学   17292篇
口腔科学   1692篇
临床医学   12732篇
内科学   32317篇
皮肤病学   875篇
神经病学   16911篇
特种医学   9094篇
外科学   29744篇
综合类   2343篇
一般理论   1篇
预防医学   18603篇
眼科学   2833篇
药学   9732篇
中国医学   656篇
肿瘤学   16680篇
  2023年   42篇
  2022年   108篇
  2021年   192篇
  2020年   108篇
  2019年   210篇
  2018年   22126篇
  2017年   17511篇
  2016年   19656篇
  2015年   1065篇
  2014年   1042篇
  2013年   1085篇
  2012年   7328篇
  2011年   21387篇
  2010年   19061篇
  2009年   11759篇
  2008年   19813篇
  2007年   22019篇
  2006年   882篇
  2005年   2501篇
  2004年   3635篇
  2003年   4622篇
  2002年   2719篇
  2001年   402篇
  2000年   585篇
  1999年   323篇
  1998年   243篇
  1997年   251篇
  1996年   126篇
  1995年   128篇
  1994年   116篇
  1993年   86篇
  1992年   114篇
  1991年   142篇
  1990年   195篇
  1989年   128篇
  1988年   90篇
  1987年   82篇
  1986年   62篇
  1985年   67篇
  1984年   45篇
  1983年   39篇
  1982年   38篇
  1980年   48篇
  1974年   24篇
  1969年   23篇
  1938年   60篇
  1937年   25篇
  1934年   30篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Septic meningitis secondary to epidural anesthesia is a rare but serious complication that is usually related to exogenous contamination from inadequate aseptic techniques, so the most frequent microorganisms observed are S. aureus and S. salivarius. We describe the case of a woman who, after receiving epidural anesthesia for normal delivery, presented septic meningitis due to E. faecium with recurrence after antibiotic treatment, probably secondary to pyogenic ventriculitis undetected in the first episode.We highlight the rarity of the case, emphasizing the need for strict aseptic technique, and review the literature on the most appropriate treatment for this type of complication.  相似文献   
992.
Four years after the latest edition, the 2015 non-ST-segment elevation acute coronary syndromes guidelines of the European Society of Cardiology have been published. Novel aspects include a new diagnostic algorithm for non-ST-segment elevation myocardial infarction using high-sensitivity cardiac troponins as well as guidance on cardiac rhythm monitoring duration. A large section is dedicated to antiplatelet therapy including initiation and duration of dual-antiplatelet therapy as well as the management of patients requiring, at the same time, long-term oral anticoagulation. New sections include the management of antiplatelet agent in patients requiring coronary artery bypass surgery and of acute bleeding events related to antiplatelet agents, vitamin K antagonist (VKA), and non-VKA oral anticoagulant drugs. Current evidence supports the radial access over the femoral one for coronary angiography and percutaneous revascularization.  相似文献   
993.
Breast-conserving therapy, which includes wide local excision of the tumor followed by irradiation, has become a standard treatment option for women with early-stage invasive breast cancer. The potential advantages of conservative breast surgery include the minor outpatient nature of the procedures, lower incidence of post-operative pain and complications, preservation of the breast and nipple areolar complex, and shorter delay to adjuvant therapy. However, not all patients are optimal candidates for breast-conserving procedures. Oncoplastic techniques combine the removal of breast cancer tumors in combination with either local volume replacement techniques to correct small defects, or by immediate reconstruction of larger defects using techniques of plastic surgery with or without contralateral breast procedures for symmetry. Therefore, oncoplastic techniques offer the potential to perform a wider excision of the tumor with an improved cosmetic result, thus potentially increasing the eligible pool for breast conservation.  相似文献   
994.
995.
996.
Cardiac hemangiomas are rare benign tumors. Here, we report the case of a man in his 30s who had a cardiac hemangioma with no symptoms. He was being treated with β-blockers for chronic heart failure with hypertensive heart disease at Osaka Minato Central Hospital. Routine echocardiography revealed a mobile spherical mass in the left ventricle that had not been detected on echocardiography performed 4 months previously. Subsequently, the tumor was excised to prevent potential embolic events and was pathologically diagnosed as a cardiac hemangioma. This case demonstrates the relatively rapid progress of a cardiac hemangioma regardless of β-blocker administration, which is occasionally used for the treatment of hemangiomas. The efficacy of β-blockers in treating cardiac hemangiomas may vary according to the type of β-blocker. Echocardiography is useful in screening and follow-up of cardiac hemangiomas; however, additional imaging modalities are needed for differential diagnosis.  相似文献   
997.
The current study shows an advanced synesthetic technique of a nitrate-fertilizer with a controlled release behavior into different soils (normal and acidic agriculture soils solutions) at different climate temperatures. The environmentally friendly and the biocompatible layered double hydroxide (LDH) clay material was used as a host to accommodate the nitrate anion into its interlayer gallery by applying a reconstruction-incorporation technique (the memory effect property of LDH that allows calcined LDH to memorize its original structure). The prepared materials were characterized by different spectroscopic techniques including; X-ray powder spectroscopy, IR, SEM, TEM, and TGA analyses. A remarkable loading ratio of the nitrate anion fertilizer was recorded into the LDH structure. Around 90 wt% of the intercalated nitrate anion was released in a sustained controlled behavior over around 24 days, while the same amount of nitrate was released over 10 days in the acidic soil. Accordingly, the present study offers a new passway for the formulation of controlled release fertilizers by using the hosting anionic clay LDH materials.  相似文献   
998.
999.
Real-time modelling of force interaction with soft tissues is of great importance for interactive surgical simulation. This paper presents a new ChainMail algorithm for real-time modelling of soft tissue deformation under force interaction. Unlike traditional ChainMails using a box-shaped bounding region, the proposed method defines an ellipsoid-shaped bounding region according to the concept of principal strains in continuum mechanics to control the movement of chain elements. Based on this ellipsoid-shaped bounding region, new position adjustment rules are developed and further integrated with temporal-domain model dynamics for dynamic simulation of soft tissue deformation. Haptic interaction with soft tissues is achieved via force input, soft tissue deformation, and force feedback. Experimental results demonstrate that the proposed ChainMail can simulate soft tissue mechanical behaviours, accommodate isotropic and homogeneous, anisotropic and heterogeneous materials, and handle large deformation. The proposed ChainMail also requires only small computational time, capable of achieving real-time computational performance.  相似文献   
1000.
The Subjective Visual Vertical (SVV) is a common test for evaluating the perception of verticality. Altered verticality has been connected with disorders in the otolithic, visual or proprioceptive systems, caused by stroke, Parkinson’s disease or multiple sclerosis, among others. Currently, this test is carried out using a variety of specific, mostly homemade apparatuses that include moving planes, buckets, hemispheric domes or a line projected in a screen. Our aim is to develop a flexible, inexpensive, user-friendly and easily extensible system based on virtual reality for the measurement of the SVV and several related visual diagnostic tests, and validate it through an experimental evaluation. Two different hardware configurations were tested with 50 healthy volunteers in a controlled environment; 28 of them were males and 22 females, with ages ranging from 18 to 49 years, being 23 the average age. The Intraclass Correlation Coefficient (ICC) was computed in each device. In addition, a usability survey was conducted. ICC?=?0.85 in the first configuration (CI?=?0.75–0.92), ICC?=?0.76 in the second configuration (CI?=?0.61–0.87), both with 95% of confidence, which means a substantial reliability. Moreover, 92.2% of subjects rated the usability of the system as “very good”. Our evaluation showed that the proposed system is suitable for the measurement of SVV in healthy subjects. The next step is to perform a more elaborated experimentation on patients and compare the results with the measurements obtained from traditional methods.  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