全文获取类型
收费全文 | 749篇 |
免费 | 40篇 |
国内免费 | 59篇 |
专业分类
儿科学 | 43篇 |
妇产科学 | 6篇 |
基础医学 | 37篇 |
口腔科学 | 13篇 |
临床医学 | 130篇 |
内科学 | 219篇 |
皮肤病学 | 17篇 |
神经病学 | 12篇 |
特种医学 | 229篇 |
外科学 | 32篇 |
综合类 | 27篇 |
预防医学 | 24篇 |
眼科学 | 8篇 |
药学 | 29篇 |
中国医学 | 2篇 |
肿瘤学 | 20篇 |
出版年
2022年 | 3篇 |
2021年 | 9篇 |
2020年 | 3篇 |
2019年 | 3篇 |
2018年 | 12篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 13篇 |
2014年 | 13篇 |
2013年 | 23篇 |
2012年 | 9篇 |
2011年 | 8篇 |
2010年 | 20篇 |
2009年 | 20篇 |
2008年 | 11篇 |
2007年 | 44篇 |
2006年 | 5篇 |
2005年 | 12篇 |
2004年 | 10篇 |
2003年 | 7篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 5篇 |
1999年 | 11篇 |
1998年 | 51篇 |
1997年 | 35篇 |
1996年 | 59篇 |
1995年 | 44篇 |
1994年 | 40篇 |
1993年 | 49篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 18篇 |
1989年 | 27篇 |
1988年 | 33篇 |
1987年 | 34篇 |
1986年 | 25篇 |
1985年 | 29篇 |
1984年 | 16篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 15篇 |
1976年 | 7篇 |
1975年 | 9篇 |
1970年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有848条查询结果,搜索用时 12 毫秒
11.
In order to study the pattern of B cell involvement in acute nonlymphocytic leukemia (ANLL), multiple B lymphoid cell lines were established by Epstein-Barr virus transformation of peripheral blood mononuclear cells from two patients with the disease who were heterozygous for the X chromosome-linked glucose-6-phosphate dehydrogenase (G6PD). In one patient, the progenitor cells involved by the leukemia exhibited multipotent differentiative expression, whereas in the other patient the cells showed differentiative expression restricted to the granulocytic pathway. In the patient whose abnormal clone showed multipotent expression, the ratio of B-A G6PD in B lymphoid cell lines was skewed in the direction of type B (the enzyme characteristic of the leukemia clone) and significantly different from the 1:1 ratio expected. It is, therefore, likely that the neoplastic event occurred in a stem cell common to the lymphoid series as well as to the myeloid series. In contrast, evidence for B cell involvement was not detected in the patient whose ANLL progenitor cells exhibited restricted differentiative expression. These findings underscore the heterogeneity of ANLL. Clinically and morphologically similar malignancies in these two patients originated in progenitors with different patterns of stem cell differentiative expression. This difference may reflect differences in cause and pathogenesis. 相似文献
12.
CGA-7 and HHF, two monoclonal antibodies that recognize muscle actin and react with adherent cells in human long-term bone marrow cultures 总被引:4,自引:0,他引:4
The CGA-7, a monoclonal antibody that reacts with smooth muscle cell actin but not with endothelial cell or fibroblast actin, and HHF, a monoclonal antibody that reacts with smooth muscle, skeletal muscle, and cardiac muscle actin, both recognize microfilaments present within adherent cells from actively hematopoietic human long-term marrow cultures. Macrophages, monocytes, and cultured marrow fibroblasts do not react with either antibody. These data suggest that the anti-actin antibodies may serve as useful markers for in vitro microenvironmental cells and lend support to the hypothesis that stromal cells from long- term marrow cultures are different from marrow fibroblasts and may constitute a unique cell lineage. 相似文献
13.
14.
15.
16.
17.
18.
Sixteen cases of histopathologically proved solitary rectal ulcer syndrome were encountered. Fifteen patients underwent barium enema study; in nine cases the findings--including rectal stricture, granularity of the mucosa, and thickened rectal folds-were nonspecific. In six cases the study was normal. All patients had a long history of defecation disorders, and defecography was performed in all. In seven cases, intussusception of the rectal wall was seen; in another case the intussusception was accompanied by a rectocele. One case showed rectal prolapse. In four cases, failed relaxation of the puborectalis occurred and prevented the passage of the bolus; in another case there was abnormal perineal descent. In two patients studies were normal. In patients with defecation disorders, the possibility of this syndrome should be considered. Defecography is the method of choice for establishing the diagnosis. 相似文献
19.
Modern population based oral health management requires a complete understanding of the impact of disease in order to provide efficient and effective oral health care and guidance. Periodontitis is an important cause of tooth loss and has been shown to be associated with a number of systemic conditions. The impact of oral conditions and disorders on quality of life has been extensively studied. However, the impact of periodontitis on quality of life has received less attention. This review summarizes the literature on the impact of periodontitis on oral health‐related quality of life (OHRQoL). Relevant publications were identified after searching the MEDLINE and EMBASE electronic databases. Screening of titles and abstracts and data extraction was conducted. Only observational studies were included in this review. Most of the reviewed studies reported a negative impact of periodontitis on OHRQoL. However, the reporting standards varied across studies. Moreover, most of the studies were conducted in developed countries. 相似文献
20.