全文获取类型
收费全文 | 4303篇 |
免费 | 212篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 102篇 |
妇产科学 | 32篇 |
基础医学 | 546篇 |
口腔科学 | 148篇 |
临床医学 | 356篇 |
内科学 | 1276篇 |
皮肤病学 | 67篇 |
神经病学 | 279篇 |
特种医学 | 257篇 |
外科学 | 526篇 |
综合类 | 26篇 |
预防医学 | 187篇 |
眼科学 | 29篇 |
药学 | 328篇 |
中国医学 | 7篇 |
肿瘤学 | 355篇 |
出版年
2023年 | 24篇 |
2022年 | 43篇 |
2021年 | 86篇 |
2020年 | 47篇 |
2019年 | 66篇 |
2018年 | 81篇 |
2017年 | 69篇 |
2016年 | 61篇 |
2015年 | 79篇 |
2014年 | 86篇 |
2013年 | 113篇 |
2012年 | 199篇 |
2011年 | 197篇 |
2010年 | 147篇 |
2009年 | 124篇 |
2008年 | 191篇 |
2007年 | 201篇 |
2006年 | 173篇 |
2005年 | 182篇 |
2004年 | 187篇 |
2003年 | 190篇 |
2002年 | 167篇 |
2001年 | 142篇 |
2000年 | 148篇 |
1999年 | 133篇 |
1998年 | 89篇 |
1997年 | 88篇 |
1996年 | 76篇 |
1995年 | 63篇 |
1994年 | 50篇 |
1993年 | 40篇 |
1992年 | 96篇 |
1991年 | 81篇 |
1990年 | 85篇 |
1989年 | 88篇 |
1988年 | 73篇 |
1987年 | 49篇 |
1986年 | 82篇 |
1985年 | 58篇 |
1984年 | 43篇 |
1983年 | 50篇 |
1982年 | 30篇 |
1981年 | 20篇 |
1980年 | 23篇 |
1979年 | 43篇 |
1978年 | 37篇 |
1977年 | 21篇 |
1976年 | 15篇 |
1975年 | 15篇 |
1973年 | 19篇 |
排序方式: 共有4538条查询结果,搜索用时 15 毫秒
61.
62.
63.
The radiologic features of ureteral and bladder hernias are poorly known. These hernias can be located in 5 compartments, being extremely rare in 2 of them--the chest and lumbar sectors, where only 2 cases are reported in literature. In the other 3 compartments--i.e., ischiatic, crural and inguinal sectors--bladder and ureteral hernias are less uncommon findings. Over a relatively short period of time, 5 bladder hernias were observed--3 ischiatic, 1 inguino-scrotal and 1 crural cases--and 1 double ureteral hernia, which was inguinal on the right-hand side and ischiatic on the left-hand side. Thus, we reviewed the main urographic and cystographic signs on the basis of a previous report by one of us. In discussing the new cases, we emphasize the importance of a few typical diagnostic signs, which follow: asymmetry and anomalous location of herniated organs, ureter protrusion beyond the pelvic bones outline, the presence of ureteral spiral ("curlicue sign"), and bladder walls indentation. 相似文献
64.
The surgical approach to minimal breast cancer is still under discussion. In fact by the term "minimal" three lesions are meant, namely "lobular carcinoma in situ", "intraductal carcinoma" and invasive "microcarcinoma". It is really difficult to indicate appropriate treatment for these tumors, also because the series reported in the literature are few and represented by a small number of cases. The present paper is a critical review of the literature on the subject. According to the most recent view lobular carcinoma in situ and intraductal carcinoma demand for radical surgery (total mastectomy) due to the high percentage of multicentricity and bilaterality of these lesions. More particularly with regard to lobular carcinoma in situ recent reports claim for a "wait and see" policy which is gaining favour, on the ground that the risk of developing invasive cancer in women with lobular carcinoma in situ is not so high and that the period of time between diagnosis of the lobular carcinoma and the development of the invasive cancer is usually very long. On the other side, for intraductal carcinoma, axillary dissection seems to be pleonastic due to the low percentage of secondary deposits in axillary lymph-nodes (1-3%) in women operated on for intraductal carcinoma. Invasive microcardinomas, less than 5 mm in diameter, should be considered as T1N0 tumors; actually there is no reason to treat them by a more conservative surgery than is done for T1N0 cancers, as they present the same involvement of the axillary lymph nodes. In a small series of 38 microcarcinoma observed at the Milan Cancer Institut N+ cases were 27%. 相似文献
65.
66.
67.
68.
NIV indications and application in critically ill patients have considerably expanded in the last few years: the aim of this paper is to shortly review NIV main indications, on the basis of data from the current scientific literature. 相似文献
69.
Gas conditioning in artificial respiration 总被引:1,自引:0,他引:1
The authors review the main systems used in the clinical setting to condition inspiratory gases during mechanical ventilation. More in details, the functional principles of hot water humidifiers and heat and moisture exchangers are described. 相似文献
70.
Thomas Armstrong Graham Packham Lindsay B Murphy Adrian C Bateman John A Conti David R Fine Colin D Johnson R Christopher Benyon John P Iredale 《Clinical cancer research》2004,10(21):7427-7437
PURPOSE: The purpose of this study was to determine the role of functional interactions between pancreatic cancer cells and pancreatic stellate cells (PSCs) in the formation of the desmoplastic reaction (DR) in pancreatic cancer and to characterize the effect of type I collagen (the predominant component of the DR) on pancreatic cancer cell phenotype. EXPERIMENTAL DESIGN: PSCs and type I collagen were identified in sections of pancreatic cancer using immunohistochemistry, and their anatomic relationship was studied. Interactions among pancreatic cancer cell lines (MIA PaCa-2, Panc-1, and AsPC-1), primary cultures of human PSCs, and type I collagen were investigated in a series of tissue culture models. RESULTS: In vivo, the DR causes gross distortion of normal pancreas, bringing cancer cells into close contact with numerous PSCs and abundant type I collagen. In tissue culture models of pancreatic cancer, conditioned media from each cell line increased PSC [3H]thymidine incorporation up to 6.3-fold that of controls, and AsPC-1 cells also increased PSC collagen synthesis 1.3-fold. Type I collagen was observed to increase long-term survival of pancreatic cancer cells treated with 5-fluorouracil, by up to 62% in clonogenic assays. This was because type I collagen increased the proliferation of cancer cells ([3H]thymidine incorporation was up to 2.8-fold that of cells cultured on tissue culture plastic) and reduced apoptosis of AsPC-1 cells in response to 5-fluorouracil (by regulating mcl-1). CONCLUSIONS: These experiments elucidate a mechanism by which the DR in pancreatic cancer may form and, via the collagen within it, promote the malignant phenotype of pancreatic cancer cells, suggesting significant detriment to the host. 相似文献