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   342篇
  免费   9篇
  国内免费   12篇
儿科学   13篇
妇产科学   4篇
基础医学   26篇
口腔科学   5篇
临床医学   31篇
内科学   77篇
皮肤病学   18篇
神经病学   1篇
特种医学   154篇
外科学   8篇
综合类   3篇
预防医学   7篇
药学   6篇
中国医学   1篇
肿瘤学   9篇
  2024年   1篇
  2023年   3篇
  2022年   1篇
  2021年   4篇
  2020年   3篇
  2019年   3篇
  2018年   3篇
  2017年   1篇
  2016年   5篇
  2015年   2篇
  2014年   5篇
  2013年   10篇
  2012年   8篇
  2011年   4篇
  2010年   9篇
  2009年   9篇
  2008年   4篇
  2007年   14篇
  2006年   5篇
  2005年   2篇
  2004年   4篇
  2003年   1篇
  2002年   1篇
  2001年   3篇
  2000年   3篇
  1999年   5篇
  1998年   13篇
  1997年   22篇
  1996年   24篇
  1995年   15篇
  1994年   17篇
  1993年   11篇
  1992年   3篇
  1991年   3篇
  1990年   5篇
  1989年   22篇
  1988年   13篇
  1987年   18篇
  1986年   17篇
  1985年   20篇
  1984年   13篇
  1983年   7篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1978年   1篇
  1977年   3篇
  1976年   3篇
  1975年   6篇
排序方式: 共有363条查询结果,搜索用时 15 毫秒
61.
62.
Recessive dystrophic epidermolysis bullosa (RDEB) is a rare form of epidermolysis bullosa (EB) that presents with generalized blistering since birth. Squamous cell carcinoma (SCC) is the most common cutaneous malignancy seen in RDEB, starting from second decade onwards. We report a case of SCC complicating RDEB in a 6-year-old girl.  相似文献   
63.
64.
Male genital tract obstructions may result from infections, previous inguinal and scrotal surgery (vasectomy) and congenital bilateral absence of the vas deferens (CBAVD). Microsurgery can sometimes be successful in treating the obstruction. In other cases and in cases of failed surgical intervention, the patient can be treated by microsurgical or percutaneous epididymal sperm aspiration (MESA, PESA) or testicular sperm extraction (TESE) and intracytoplasmic sperm injection (ICSI). We present the results of 39 ICSI procedures for obstructive azoospermia in 24 couples. The aetiology of the obstruction was failed microsurgery in 11 patients, CBAVD in nine and genital infections in four. Sperm retrieval was accomplished via MESA in four cases, PESA in 18 cases and via TESE in 11 cases. TESE was only applied when PESA failed to produce enough spermatozoa for simultaneous ICSI. In six patients, the ICSI procedure was performed with cryopreserved spermatozoa after an initial PESA procedure. Fertilization occurred in 47% of the metaphase II oocytes; embryo transfer was performed in 92% of procedures and resulted in a clinical pregnancy in 13/39 procedures. Ongoing pregnancy was achieved in 10/39 procedures. One pregnancy was terminated early after prenatal investigation showed a cytogenetic abnormality (47,XX+18, Edwards syndrome). The other nine pregnancies resulted in the live birth of 10 children, without any congenital abnormalities. Epididymal and testicular retrieved spermatozoa were successfully used for ICSI to treat obstructive azoospermia, and resulted in an ongoing pregnancy in 10 of 24 couples (41.6%) after 39 ICSI procedures, a success rate of 25.6% per treatment cycle and of 27.7% per embryo transfer.   相似文献   
65.
In a human in-vitro fertilization (IVF) programme, the effect of co- culture of embryos with human fibroblasts was evaluated with respect to pregnancy rate and embryo development. Patients were included in the study after giving informed written consent. The IVF treatments were randomly assigned by stratification of both age (<36 versus > or =36 years) and previous IVF attempts (yes versus no). After fertilization was established, the zygotes were transferred to a 4-well dish with or without fibroblasts and cultured for 2 days. On the third day after ovum pick-up (OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were scored and a maximum of three embryos was transferred. Supernumerary embryos of good quality were cryopreserved. The design of this study was a group sequential trial with the objective of detecting differences between pregnancy rates following IVF with conventional incubation or incubation in co-culture with fibroblasts. This design included one evaluation at half-way data collection. In the study, 148 patients had an OPU, of whom 77 were allocated to the co-culture group. There was no statistically significant difference in pregnancy rate, cell number and embryo quality between the two groups. The ongoing pregnancy rate per embryo transfer was 27% in co-culture and 30% in the conventional culture group. The implantation rates per transferred embryo were 17 and 18% respectively. Using a multivariate logistic regression model for the probability of ongoing pregnancies, the odds ratio of co-culture, adjusted for age and previous IVF attempts, was not statistically significant. In conclusion, co-culture with human fibroblasts does not contribute to an improvement of embryo quality nor to a higher pregnancy rate after IVF in an unselected group of patients.   相似文献   
66.
B7-1和IL-12基因转染对肝癌细胞免疫原性的影响   总被引:1,自引:1,他引:1  
目的 观察B7-1和IL-12基因表达对人肝癌细胞免疫原性原影响。方法 分别将B7-1和IL-12基因以逆转录病毒介导转染HepG2细胞。阳性克隆细胞与健康人外周血淋巴细胞(PBL)混合培养后,用流式细胞仪检测PBL表面Ⅰ类人白细胞抗原(HLA-Ⅰ)分子表达,以MTT法检测PBL的特异性杀伤活性K562细胞的活性。结果 混合HepG2/B7-1HepG2/IL-12细胞组PBL表面的HLA-Ⅰ分子  相似文献   
67.
68.
69.
70.
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