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   284篇
  免费   17篇
  国内免费   6篇
耳鼻咽喉   1篇
儿科学   5篇
妇产科学   3篇
基础医学   36篇
口腔科学   11篇
临床医学   29篇
内科学   44篇
皮肤病学   9篇
神经病学   2篇
特种医学   45篇
外科学   25篇
综合类   66篇
预防医学   12篇
药学   3篇
中国医学   1篇
肿瘤学   15篇
  2023年   1篇
  2022年   1篇
  2021年   3篇
  2019年   4篇
  2018年   3篇
  2017年   3篇
  2016年   4篇
  2015年   7篇
  2014年   7篇
  2013年   10篇
  2012年   5篇
  2011年   2篇
  2010年   19篇
  2009年   17篇
  2008年   19篇
  2007年   24篇
  2006年   15篇
  2005年   7篇
  2004年   11篇
  2003年   7篇
  2002年   3篇
  2001年   3篇
  2000年   5篇
  1999年   13篇
  1998年   22篇
  1997年   15篇
  1996年   15篇
  1995年   5篇
  1994年   10篇
  1993年   8篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1989年   13篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   3篇
  1984年   1篇
  1983年   3篇
  1982年   1篇
  1981年   1篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
排序方式: 共有307条查询结果,搜索用时 15 毫秒
81.
The question of payment to egg donors has recently focused the attention of both the Human Fertilisation and Embryology Authority (HFEA) and licensed clinics. An acute shortage of egg donors and the rising costs of assisted conception treatment are matters of grave concern to many patients. To understand the emotional and social effects of egg sharing and egg donation, we conducted a survey of attitudes in a group of women who had some knowledge or experience of egg donation. A total of 750 questionnaires were sent out of which 217 were returned within the specified time limit. From these, 107 respondents had experience of egg donation and 110 had made enquiries about donation. The data from these questionnaires were collated and tabulated by the National Opinion Polls (NOP) Research Group. An analysis of the data produced the following key findings: (i) donating or sharing eggs is a social issue, 94% discuss it with partners/family/friends; (ii) altruistic motives are not the prerogative of non-patient volunteers-egg share donors felt that helping the childless was as important as having a chance of in-vitro fertilization (IVF) for themselves; (iii) the treatment procedure causes the most anxiety for egg donors. The recipients were most concerned about delays, donor characteristics and how the eggs were allocated; (iv) most respondents (65%) with prior experience of egg sharing would do it again - 63% of egg share donors, 72% of egg share recipients; (v) cash rewards to egg donors and outright advertising for donors were rejected by 64 and 62% of the sample respectively; and (vi) counselling was highly valued and there were no instances of 'shattered lives' after treatment. The findings do not support the recently announced intentions of the HFEA to disallow payment to gamete donors on the grounds of devalued consent. There is no precedent in modern medicine for egg sharing. The patients surveyed drew a clear distinction between egg sharing and financial rewards. As long as egg donation is not covered by the National Health Service, it is fairer to offer egg sharing than to refuse treatment to those unable to pay.   相似文献   
82.
This paper describes the first pregnancy in a childless widow after intracytoplasmic sperm injection (ICSI) treatment with her deceased husband's spermatozoa which had been stored for nearly 3 years before use. Before his death the husband had received treatment for testicular cancer and he had given the appropriate written consent for the future use of his spermatozoa. Of the 10 eggs injected, six resulted in normal embryos. Three embryos were transferred and the remaining three embryos are currently stored for possible future use. The treatment resulted in a continuing singleton pregnancy. The case demonstrated the suitability of ICSI in those difficult cases where the sperm quality is extremely poor. This success is also compared with a widely debated case of another widow who was refused permission to use her deceased husband's spermatozoa. It is concluded that in the case of posthumous use of frozen spermatozoa, the current laws are conveniently applicable in a chronic illness but not so in an acute illness leading to death. In the light of the wide public debate on the issues raised by this legal case, the UK Government has also decided to conduct a review of consent procedures involving the storage and use of genetic material.   相似文献   
83.
84.
The meiotic segregation of 24 spermatozoa obtained from a 47,XXY male is described. Three-colour fluorescence in-situ hybridization with probes for chromosomes X, Y and 18 was used. Five spermatozoa carried an X chromosome, seven carried a Y, six had an XY gonosomal complement, five were missing the sex chromosome and one spermatozoon was presumably diploid with an XX/1818 complement. Our results support the hypothesis that XXY cells are able to complete meiosis. In this patient, the percentage of spermatozoa with an abnormal number of sex chromosomes increased from 1/6 (17%) among spermatozoa with normal morphology to 11/18 (61%) in spermatozoa with abnormal morphology.   相似文献   
85.
We report the case of an 8 week old infant with fulminant autoimmune haemolytic anaemia refractory to conventional immunomodulating treatment. Massive haemolysis resulted in cardiac decompensation and acute renal failure which necessitated mechanical ventilation and peritoneal dialysis. Rituximab, a chimeric anti-CD20 monoclonal antibody, halted progression of the haemolytic process, but the patient died of acute viral pneumonia and disseminated fungal infection. Earlier introduction of rituximab might have prevented the renal complications. Paediatricians should be aware of this useful therapeutic tool for treatment of refractory autoimmune haemolytic anaemia and balance its use against the risk of potential life threatening infection.  相似文献   
86.
87.
自美国国家骨髓库(NMDP)开展第一例无关供者移植以来,至今已有20年.NMDP目前的库容量已逾700万,已为6大洲提供了30 000多份无关供者造血干细胞.这一辉煌成就是美国国家骨髓库600多名工作人员共同努力的结果,同时也得益于广泛的国际合作,包括171个移植中心,73个供者中心,24个脐血库,97个骨髓采集中心,91个血液净化中心,26个HLA分型实验室和26个合作供者登记处.本文回顾了美国国家骨髓库的历史,阐述了20年来移植病人、移植物来源和预处理方案几方面的主要变化趋势.  相似文献   
88.
自美国国家骨髓库(NMDP)开展第一例无关供者移植以来,至今已有20年.NMDP目前的库容量已逾700万,已为6大洲提供了30 000多份无关供者造血干细胞.这一辉煌成就是美国国家骨髓库600多名工作人员共同努力的结果,同时也得益于广泛的国际合作,包括171个移植中心,73个供者中心,24个脐血库,97个骨髓采集中心,91个血液净化中心,26个HLA分型实验室和26个合作供者登记处.本文回顾了美国国家骨髓库的历史,阐述了20年来移植病人、移植物来源和预处理方案几方面的主要变化趋势.  相似文献   
89.
90.
McMurdo  KK; de Geer  G; Webb  WR; Gamsu  G 《Radiology》1986,159(1):33-38
The potential of magnetic resonance (MR) imaging to demonstrate the mediastinal veins was evaluated retrospectively in 25 patients with no evidence of a venous abnormality, 28 patients who had narrowing or occlusion of a mediastinal vein, and two patients who had a venous anomaly. In patients with venous occlusion, the MR images graphically demonstrated the sites and extent. MR images also demonstrated slow flow within venous structures proximal to the obstruction. Generally, venous collaterals in the mediastinum and chest wall were better seen with contrast material-enhanced computed tomography scans. The marked contrast on MR images between the signal void of normal vascular structures, the moderate signal intensity of tumor, and the high signal intensity of a thrombus or slowly flowing blood allows ready detection of venous occlusion and may suggest the nature of the occlusion.  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