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   7066篇
  免费   332篇
  国内免费   74篇
耳鼻咽喉   111篇
儿科学   136篇
妇产科学   266篇
基础医学   524篇
口腔科学   131篇
临床医学   603篇
内科学   1940篇
皮肤病学   88篇
神经病学   368篇
特种医学   289篇
外科学   1380篇
综合类   29篇
预防医学   381篇
眼科学   157篇
药学   312篇
中国医学   3篇
肿瘤学   754篇
  2023年   43篇
  2022年   114篇
  2021年   239篇
  2020年   130篇
  2019年   195篇
  2018年   206篇
  2017年   146篇
  2016年   164篇
  2015年   169篇
  2014年   299篇
  2013年   334篇
  2012年   590篇
  2011年   608篇
  2010年   365篇
  2009年   333篇
  2008年   578篇
  2007年   588篇
  2006年   491篇
  2005年   412篇
  2004年   358篇
  2003年   321篇
  2002年   276篇
  2001年   57篇
  2000年   38篇
  1999年   51篇
  1998年   57篇
  1997年   28篇
  1996年   35篇
  1995年   27篇
  1994年   21篇
  1993年   13篇
  1992年   23篇
  1991年   17篇
  1990年   19篇
  1989年   8篇
  1988年   9篇
  1987年   9篇
  1986年   13篇
  1985年   6篇
  1984年   10篇
  1983年   6篇
  1982年   12篇
  1981年   5篇
  1980年   6篇
  1978年   3篇
  1976年   7篇
  1975年   4篇
  1974年   9篇
  1973年   3篇
  1972年   4篇
排序方式: 共有7472条查询结果,搜索用时 15 毫秒
61.
In Huntington disease (HD), immune cells are activated before symptoms arise; however, it is unclear how the expression of mutant huntingtin (htt) compromises the normal functions of immune cells. Here we report that primary microglia from early postnatal HD mice were profoundly impaired in their migration to chemotactic stimuli, and expression of a mutant htt fragment in microglial cell lines was sufficient to reproduce these deficits. Microglia expressing mutant htt had a retarded response to a laser-induced brain injury in vivo. Leukocyte recruitment was defective upon induction of peritonitis in HD mice at early disease stages and was normalized upon genetic deletion of mutant htt in immune cells. Migration was also strongly impaired in peripheral immune cells from pre-manifest human HD patients. Defective actin remodeling in immune cells expressing mutant htt likely contributed to their migration deficit. Our results suggest that these functional changes may contribute to immune dysfunction and neurodegeneration in HD, and may have implications for other polyglutamine expansion diseases in which mutant proteins are ubiquitously expressed.  相似文献   
62.
A 42-year-old woman undertook a chest radiograph for a routine evaluation prior to surgery for pelvic endometrioma, which revealed a right paratracheal mass slightly displacing the trachea to the left. CT of the thorax disclosed a well demarcated, heterogeneous, lobular, right paratracheal mass, bearing punctate, coarse, and curvilinear calcifications. MRI further revealed two components within the lesion: a larger, cystic, exhibiting thin septations, and a solid component at the lower part exhibiting strong enhancement. No continuity of the mass with the thyroid gland was demonstrated, which had normal size and no focal lesion. Histological examination of the resected mass disclosed lymph node tissue infiltrated by papillary thyroid carcinoma; subsequent total thyroidectomy revealed small foci of papillary carcinoma within both lobes of the thyroid gland. Ablative dose I-131 was administered and the patient was put on daily thyroid supplements.  相似文献   
63.
Esophageal intramural pseudodiverticulosis (EIP) is a rare disorder of unknown etiology. On histopathology, it is characterized by dilation of the submucosal esophageal glands. The main presenting symptom is dysphagia to solid foods. Most patients diagnosed with EIP also have a history of diabetes mellitus, gastroesophageal reflux disease, esophageal candidiasis, or chronic alcohol and nicotine abuse. Yet, the exact pathophysiologic mechanism still remains unclear. The most frequent complication, occurring in 80 % of the patients, is esophageal stricture. The mainstay of therapy is directed towards symptom relief with administration of proton pump inhibitors (PPIs) combined with antifungals and/or endoscopic dilations, if necessary. We report a case of a 69-year-old man who presented with a 9-month history of progressive dysphagia and a 25 kg-weight loss, with typical endoscopic findings of EIP and successful response to medical therapy with oral antifungals alone.  相似文献   
64.
65.
Purpose: To evaluate macular thickness (MT) changes, using spectral domain optical coherence tomography (SD-OCT) in patients with optic disc pit (ODP) maculopathy after pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) peeling. Procedures: Our retrospective study included nine patients with ODP maculopathy, treated with either PPV (n?=?5) or PPV with ILM peeling (n?=?4). All participants, who had a mean long-term follow-up of 33.4?±?7.0 months, underwent a complete ophthalmological examination and SD-OCT. Due to the preoperative macular elevation, the postoperative MT in the operated patients was compared with that of fellow eyes and with normative data. Results: A significant reduction in MT was noticed in all macular sectors of the operated cases at the last examination. The reduction was more evident in the group of PPV with ILM peeling. At the last examination of the follow-up, there was a statistically significant improvement regarding BCVA in both groups in comparison with baseline, while the two groups did not differ significantly in between (p?=?0.245). Conclusions: In the long-term follow-up period, our study demonstrated a significant reduction in MT in patients with ODP maculopathy treated with PPV, which was more profound in those cases where PPV included ILM peeling.  相似文献   
66.
The “exposome” is a term recently used to describe all environmental factors, both exogenous and endogenous, which we are exposed to in a lifetime. It represents an important tool in the study of autoimmunity, complementing classical immunological research tools and cutting-edge genome wide association studies (GWAS). Recently, environmental wide association studies (EWAS) investigated the effect of environment in the development of diseases. Environmental triggers are largely subdivided into infectious and non-infectious agents. In this review, we introduce the concept of the “infectome”, which is the part of the exposome referring to the collection of an individual's exposures to infectious agents. The infectome directly relates to geoepidemiological, serological and molecular evidence of the co-occurrence of several infectious agents associated with autoimmune diseases that may provide hints for the triggering factors responsible for the pathogenesis of autoimmunity. We discuss the implications that the investigation of the infectome may have for the understanding of microbial/host interactions in autoimmune diseases with long, pre-clinical phases. It may also contribute to the concept of the human body as a superorganism where the microbiome is part of the whole organism, as can be seen with mitochondria which existed as microbes prior to becoming organelles in eukaryotic cells of multicellular organisms over time. A similar argument can now be made in regard to normal intestinal flora, living in symbiosis within the host. We also provide practical examples as to how we can characterise and measure the totality of a disease-specific infectome, based on the experimental approaches employed from the “immunome” and “microbiome” projects.  相似文献   
67.
68.
69.

Purpose  

Prevention of perioperative activation of intestinal muscularis macrophages is a promising intervention to avoid post-traumatic gastrointestinal tract dysfunction. However, impaired macrophage function could have deleterious consequences on anastomotic healing, especially in complications aggravating the healing process itself, such as infectious problems either as preexisting local inflammation or infection (e.g., complicated diverticulitis) or endotoxemia due to early postoperative infections (e.g., pneumonia). Aim of this study was to investigate colonic anastomotic healing in macrophage-depleted mice in the presence of endotoxemia.  相似文献   
70.
Several lines of evidence from basic research indicate that B cells may contribute to the pathogenesis of systemic sclerosis. Clinical studies as well have provided preliminary data pointing to the direction that B-cell depletion with rituximab might be a therapeutic option for patients with this debilitating disease.  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