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   67898篇
  免费   4687篇
  国内免费   1343篇
耳鼻咽喉   1044篇
儿科学   2277篇
妇产科学   1066篇
基础医学   7844篇
口腔科学   1252篇
临床医学   5209篇
内科学   11826篇
皮肤病学   1102篇
神经病学   15162篇
特种医学   1663篇
外国民族医学   10篇
外科学   5917篇
综合类   3943篇
现状与发展   3篇
一般理论   7篇
预防医学   4380篇
眼科学   1345篇
药学   5102篇
  21篇
中国医学   2242篇
肿瘤学   2513篇
  2024年   135篇
  2023年   1326篇
  2022年   2345篇
  2021年   3722篇
  2020年   3269篇
  2019年   4187篇
  2018年   3973篇
  2017年   3143篇
  2016年   2440篇
  2015年   2369篇
  2014年   5094篇
  2013年   6499篇
  2012年   4139篇
  2011年   3977篇
  2010年   3075篇
  2009年   2806篇
  2008年   2638篇
  2007年   2118篇
  2006年   1691篇
  2005年   1390篇
  2004年   1406篇
  2003年   1231篇
  2002年   931篇
  2001年   765篇
  2000年   742篇
  1999年   605篇
  1998年   534篇
  1997年   555篇
  1996年   384篇
  1995年   300篇
  1994年   293篇
  1993年   255篇
  1992年   194篇
  1991年   190篇
  1990年   162篇
  1989年   132篇
  1988年   115篇
  1985年   618篇
  1984年   653篇
  1983年   421篇
  1982年   501篇
  1981年   436篇
  1980年   352篇
  1979年   338篇
  1978年   282篇
  1977年   219篇
  1976年   212篇
  1975年   233篇
  1974年   170篇
  1973年   180篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
《Clinical neurophysiology》2021,132(10):2357-2364
ObjectivesTo investigate the subcortical somatosensory evoked potentials (SEPs) to electrical stimulation of either muscle or cutaneous afferents.MethodsSEPs were recorded in 6 patients suffering from Parkinson’s disease (PD) who underwent electrode implantation in the pedunculopontine (PPTg) nucleus area. We compared SEPs recorded from the scalp and from the intracranial electrode contacts to electrical stimuli applied to: 1) median nerve at the wrist, 2) abductor pollicis brevis motor point, and 3) distal phalanx of the thumb. Also the high-frequency oscillations (HFOs) were analysed.ResultsAfter median nerve and pure cutaneous (distant phalanx of the thumb) stimulation, a P1-N1 complex was recorded by the intracranial lead, while the scalp electrodes recorded the short-latency far-field responses (P14 and N18). On the contrary, motor point stimulation did not evoke any low-frequency component in the PPTg traces, nor the N18 potential on the scalp. HFOs were recorded to stimulation of all modalities by the PPTg electrode contacts.ConclusionsStimulus processing within the cuneate nucleus depends on modality, since only the cutaneous input activates the complex intranuclear network possibly generating the scalp N18 potential.SignificanceOur results shed light on the subcortical processing of the somatosensory input of different modalities.  相似文献   
3.
4.
AimThe aim of the study was to describe the characteristics of the Bachelor’s thesis of fourth-year nursing students at a Spanish public university, the criteria that students used to choose a topic and students’ degree of satisfaction after completing the Bachelor’s thesis.DesignQuantitative study.MethodsWe examined 420 Bachelor’s theses carried out from 2013 to 2018 and conducted an online survey among fourth-year students in the 2017–18 and 2018–19 academic years (81 completed questionnaires).ResultsThe Bachelor’s thesis took the form of a research proposal. The most frequent proposal type was a qualitative hospital-based study whose objective was to understand the experiences of adult or adolescent patients, close family members, or nurses. Students chose topics for personal reasons. Most participants reported feeling satisfied with the knowledge and skills acquired.ConclusionsStudents completing a Bachelor’s thesis in the form of a research proposal have the potential to transfer their research skills to their nursing practice.  相似文献   
5.
6.
7.
Inflammatory bowel disease (IBD) is a chronic disease that requires chronic treatment throughout the evolution of the disease, with a complex physiopathology that entails great challenges for the development of new and specific treatments for ulcerative colitis and Crohn´s disease. The anti-tumor necrosis factor alpha therapy has impacted the clinical course of IBD in those patients who do not respond to conventional treatment, so there is a need to develop new therapies and markers of treatment response. Various pathways involved in the development of the disease are known and the new therapies have focused on blocking the inflammatory process at the gastrointestinal level by oral, intravenous, subcutaneous, and topical route. All these new therapies can lead to more personalized treatments with higher success rates and fewer relapses. These treatments have not only focused on clinical remission, but also on achieving macroscopic changes at the endoscopic level and microscopic changes by achieving mucosal healing. These treatments are mainly based on modifying signaling pathways, by blocking receptors or ligands, reducing cell migration and maintaining the integrity of the epithelial barrier. Therefore, this review presents the efficacy and safety of the new treatments that are currently under study and the advances that have been made in this area in recent years.  相似文献   
8.
Barrett's esophagus (BE) is the precursor to esophageal adenocarcinoma (EAC). Progression to cancer typically occurs in a stepwise fashion through worsening dysplasia and ultimately, invasive neoplasia. Established EAC with deep involvement of the esophageal wall and/or metastatic disease is invariably associated with poor long-term survival rates. This guides the rationale of surveillance of Barrett’s in an attempt to treat lesions at an earlier, and potentially curative stage. The last two decades have seen a paradigm shift in management of Barrett’s with rapid expansion in the role of endoscopic eradication therapy (EET) for management of dysplastic and early neoplastic BE, and there have been substantial changes to international consensus guidelines for management of early BE based on evolving evidence. This review aims to assist the physician in the therapeutic decision-making process with patients by comprehensive review and summary of literature surrounding natural history of Barrett’s by histological stage, and the effectiveness of interventions in attenuating the risk posed by its natural history. Key findings were as follows. Non-dysplastic Barrett’s is associated with extremely low risk of progression, and interventions cannot be justified. The annual risk of cancer progression in low grade dysplasia is between 1%-3%; EET can be offered though evidence for its benefit remains confined to highly select settings. High-grade dysplasia progresses to cancer in 5%-10% per year; EET is similarly effective to and less morbid than surgery and should be routinely performed for this indication. Risk of nodal metastases in intramucosal cancer is 2%-4%, which is comparable to operative mortality rate, so EET is usually preferred. Submucosal cancer is associated with nodal metastases in 14%-41% hence surgery remains standard of care, except for select situations.  相似文献   
9.
10.
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