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   295篇
  免费   21篇
  国内免费   24篇
儿科学   27篇
妇产科学   4篇
基础医学   18篇
口腔科学   8篇
临床医学   33篇
内科学   72篇
皮肤病学   5篇
神经病学   12篇
特种医学   44篇
外科学   22篇
综合类   40篇
预防医学   10篇
眼科学   5篇
药学   21篇
肿瘤学   19篇
  2022年   3篇
  2021年   2篇
  2020年   4篇
  2019年   4篇
  2018年   5篇
  2017年   5篇
  2016年   4篇
  2015年   7篇
  2014年   10篇
  2013年   13篇
  2012年   4篇
  2011年   5篇
  2010年   14篇
  2009年   14篇
  2008年   9篇
  2007年   19篇
  2006年   8篇
  2005年   3篇
  2004年   5篇
  2003年   5篇
  2002年   5篇
  2001年   9篇
  2000年   4篇
  1999年   4篇
  1998年   21篇
  1997年   19篇
  1996年   19篇
  1995年   9篇
  1994年   19篇
  1993年   11篇
  1992年   5篇
  1991年   6篇
  1989年   8篇
  1988年   14篇
  1987年   5篇
  1986年   7篇
  1985年   5篇
  1984年   5篇
  1983年   2篇
  1982年   5篇
  1981年   5篇
  1980年   5篇
  1978年   1篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
排序方式: 共有340条查询结果,搜索用时 12 毫秒
51.
52.
53.
54.
55.
We describe the development of a human bone marrow (BM) culture system which allows study of the interaction of stromal cell lines (SCL) and highly purified hematopoietic progenitor cells. Normal BM stromal cells were electroporated with a plasmid containing the simian virus 40 (SV40) large T antigen (SV40 T Ag) under the control of a synthetic metallothionein promoter (MT4); this construct is designated MT4 SV40 T Ag. SCL in which the rate of proliferation could be controlled by altering the zinc (Zn) concentration were characterized, demonstrating that the SCL were heterogeneous with respect to G-CSF and GM-CSF production. Suppression of SCL proliferation on removal of Zn made it possible to use these lines in coculture with purified CD34+ progenitor cells from umbilical cord blood. The ability to control proliferation of SCL has allowed us to maintain the survival and expansion of colony- forming cells in culture for up to 2 months. These lines have enabled us to test for stromal cell characteristics at a clonal level and provided us with a tool to analyze the events leading to lineage commitment and hematopoietic differentiation, as demonstrated by suppression of hematopoiesis by an antibody directed against the c-kit molecule.  相似文献   
56.
57.

Introduction

Rectal polypectomy causes thinning (or even perforation) of the rectal wall in addition to thermic injury at the polypectomy site.

Case report

We present a rare case of spontaneous rectal perforation after uncomplicated nerve sparing endoscopic extraperitoneal radical prostatectomy in a patient with a previous history of rectal polypectomy at the perforation site. The patient could be treated conservatively. There was complete healing of the fistula without any effect on functional results. This Conservative therapy for such rectal perforations is indicated if the patient''s general condition remains stable without any signs of infection.

Conclusions

Polypectomy is an important risk factor for rectal perforation during nsEERPE. Adequate time interval should be given to allow healing and avoid adding further thermal wall damage which may obscure healing leading to complications like fistula. Conservative therapy for small missed rectal perforations constitutes an attractive, feasible and non invasive treatment entity. Following this principle we have not faced this complication in following similar cases.  相似文献   
58.
A 28-year-old Chinese man presented with acute bleeding per rectum. Computed tomography showed a posterior outpouching arising from the distal ileum. The outpouching had hyperaemic walls, but no active contrast extravasation was detected. Technetium-99m pertechnetate scintigraphy showed focal areas of abnormal uptake in the right side of the pelvis, superior and posterior to the urinary bladder. These areas of uptake appeared simultaneously with the gastric uptake and demonstrated gradual increase in intensity on subsequent images. The diagnosis of Meckel’s diverticulum was confirmed on surgery and the lesion was resected. The clinical and imaging features of Meckel’s diverticulum are discussed.  相似文献   
59.
Male infertility is a clinical manifestation which concerns approximately 15 % of all couples in Europe. Male causes for infertility are found in 50% of involuntarily childless couples. For Germany this counts for a number of an equivalent of 50 000 men/year, No causal factor is found in 60%-75% of cases (idiopathic male infertility). Nevertheless, reduced male fertility can be the result of congenital and acquired urogenital abnormalities, increased scrotal temperature (varicocele), endocrine disturbances, genetic abnormalities and immunological factors. Furthermore, urogenital inflammations and infections play an important role. Indications for microbiological assessment include abnormal urine samples, urinary tract infections, prostatitis, epididymitis, orchitis, ejaculate infections and sexually transmitted diseases. In the following review, different infectious diseases of the male urogenital tract and their implications on fertility were reviewed.  相似文献   
60.
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