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   14675篇
  免费   877篇
  国内免费   71篇
耳鼻咽喉   73篇
儿科学   547篇
妇产科学   349篇
基础医学   2043篇
口腔科学   258篇
临床医学   1430篇
内科学   3123篇
皮肤病学   367篇
神经病学   1495篇
特种医学   314篇
外科学   1516篇
综合类   85篇
一般理论   16篇
预防医学   1206篇
眼科学   297篇
药学   974篇
中国医学   25篇
肿瘤学   1505篇
  2024年   19篇
  2023年   161篇
  2022年   278篇
  2021年   508篇
  2020年   308篇
  2019年   430篇
  2018年   473篇
  2017年   379篇
  2016年   380篇
  2015年   473篇
  2014年   618篇
  2013年   796篇
  2012年   1246篇
  2011年   1167篇
  2010年   693篇
  2009年   587篇
  2008年   993篇
  2007年   998篇
  2006年   950篇
  2005年   868篇
  2004年   831篇
  2003年   771篇
  2002年   617篇
  2001年   71篇
  2000年   64篇
  1999年   95篇
  1998年   110篇
  1997年   95篇
  1996年   85篇
  1995年   65篇
  1994年   52篇
  1993年   59篇
  1992年   49篇
  1991年   40篇
  1990年   20篇
  1989年   26篇
  1988年   22篇
  1987年   22篇
  1986年   17篇
  1985年   26篇
  1984年   23篇
  1983年   18篇
  1982年   17篇
  1981年   10篇
  1980年   15篇
  1979年   11篇
  1978年   9篇
  1977年   11篇
  1972年   7篇
  1971年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
A recent study put forward the hypothesis that microlithiasis may represent an early stage in the development of biliary calculi. It is an established fact that cholesterol crystals are the product of an inevitable stage in the sequence leading to gallstone formation. To test the hypothesis stated above ten patients affected by gallbladder cholesterol microlithiasis (CM) were examined in the lipid composition of the bile, the cholesterol saturation index and the presence of cholesterol crystals being calculated. The results were compared with those of 14 patients affected by pigment microliths, 24 with larger stones (LS) and ten control patients. The cholesterol saturation index was above one in all CM patients, whereas in some LS patients the gall-bladder bile was not supersaturated. Cholesterol crystals were observed in the gallbladders of all CM patients and seven LS patients. These results would seem to provide support for the hypothesis of microcalculi as being "young stones", with the bile of CM patients maintaining the conditions leading to gallstone formation.  相似文献   
42.

Background  

Osteoclasts (OCs) are involved in rheumatoid arthritis and in several pathologies associated with bone loss. Recent results support the concept that some medicinal plants and derived natural products are of great interest for developing therapeutic strategies against bone disorders, including rheumatoid arthritis and osteoporosis. In this study we determined whether extracts of Emblica officinalis fruits display activity of possible interest for the treatment of rheumatoid arthritis and osteoporosis by activating programmed cell death of human primary osteoclasts.  相似文献   
43.
44.
45.
During the last few years, studies have revealed that the need for psychosocial support and concrete social services are great in the early stages of the treatment of rheumatic diseases. The ability to keep a job, to do household chores, to participate in leisure activities and to maintain social relations is clearly impaired. Anxiety and depression are not unusual and often associated with weak support from relatives, loneliness and disturbed family relations. Nevertheless, the patients report resilience and determination to cope with the impacts of illness. Crisis intervention, vocational guidance and counselling about problems concerning the disease should be available and offered to the patients. As the patients seem to be unaccustomed to talking about their psychosocial problems, an empathetic and information-seeking attitude on the part of the health care staff is essential.  相似文献   
46.
Acrocentric interconnections and NOR (nucleolus organizer region) variants are frequently observed in silver-stained metaphase preparations from lymphocytes of phenotypically normal individuals. The types of interconnections and of NOR variants are outlined. It is speculated that the satellite acrocentrics (both normal and variant) are the consequence of breakage and recoiling of these interconnections. Awareness of these two features of the human genome may facilitate understanding of the NOR/nucleolus interaction(s) in such important processes as nucleolus formation and in development and/or diagnosis of disease states (i.e., malignancy).  相似文献   
47.
OBJECTIVE: To examine, using direct observation methodology, differences in family functioning at mealtime between families of school-age children with cystic fibrosis (CF) and families of school-age children without a chronic illness. METHOD: Family functioning was rated using the McMaster Mealtime Interaction Coding System (MICS) during a videotaped dinner among 28 families of children with CF and 27 families of non-ill, age-matched peers. Families were rated on overall family functioning and on six dimensions of the MICS: task accomplishment, communication, affect management, interpersonal involvement, behavior control, and role allocation. RESULTS: Ratings for families of a child with CF were significantly lower than they were for comparison families on overall family functioning and on four of the six MICS dimensions: communication, affect management, interpersonal involvement, and behavioral control. Moreover, a significantly greater percentage of families of children with CF were rated in the unhealthy range on overall family functioning and on five of six MICS dimensions. There was no relationship between family functioning and child weight status for children with CF. CONCLUSIONS: The current study suggests that for families of school-age children with CF, the family system is negatively affected during mealtime. Dietary interventions need to address family-centered, as well as child-centered, interventions to help families manage challenges presented during the family meal.  相似文献   
48.

Background  

We present our experience of therapeutic vaccination using dendritic cells (DC) pulsed with autologous tumor antigens in patients with advanced melanoma.  相似文献   
49.
Current digital information systems in radiology are insufficient to accommodate the retrieval needs of academicians. Significant efforts are required in retrieving clinical cases for teaching and research. We describe a prototype system that supports intelligent case retrieval based on a combined specification of patient demographics, radiologic findings, and pathologic diagnoses. The documents for these cases can be distributed among multiple heterogeneous data bases. The system features automatic indexing of radiology and pathology reports, a comprehensive lexicon for thoracic radiology, an interface to a hospital information system, radiology information system, and picture archiving and communication systems, and a graphical user interface for query formulation and results visualization. The prototype system was developed within the domain of thoracic radiology involving patients with lung cancer.  相似文献   
50.
Mutations of the LMNA gene encoding the lamin A and C nuclear envelope proteins cause an autosomal dominant form of dilated cardiomyopathy (DCM) with atrioventricular block (AVB). The aim of this study was to investigate ultrastructural nuclear membrane changes by conventional electron microscopy and protein expression by immuno-electron microscopy in the heart of patients with DCM and AVB due to LMNA gene mutations. Four immunohistochemical techniques were used: pre-embedding and post-embedding in Epon-Araldite resin and London Resin White (LRW), with and without silver enhancement. Parallel light microscopy immunohistochemistry studies were performed. Conventional electron microscopy showed a loss of integrity of the myocyte nuclei with blebs of the nuclear membrane, herniations and delamination of the nuclear lamina and nuclear pore clustering. Post-embedding LRW was the most informative technique for morphology and immuno-labelling. Immuno-labelling was almost absent in the nuclear envelope of patients with LMNA gene mutations, but intensely present in controls. The loss of labelling selectively affected myocyte nuclei; the endothelial cell nuclei were immunostained in patients and controls. Light immunohistochemistry confirmed the results. These findings confirm the hypothesis that LMNA gene defects are associated with a loss of protein expression in the selective compartment of non-cycling myocyte nuclei.  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