全文获取类型
收费全文 | 920篇 |
免费 | 71篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 49篇 |
妇产科学 | 13篇 |
基础医学 | 124篇 |
口腔科学 | 50篇 |
临床医学 | 116篇 |
内科学 | 221篇 |
皮肤病学 | 34篇 |
神经病学 | 29篇 |
特种医学 | 131篇 |
外科学 | 62篇 |
综合类 | 40篇 |
预防医学 | 43篇 |
眼科学 | 5篇 |
药学 | 41篇 |
中国医学 | 2篇 |
肿瘤学 | 40篇 |
出版年
2023年 | 5篇 |
2022年 | 4篇 |
2021年 | 18篇 |
2020年 | 12篇 |
2019年 | 19篇 |
2018年 | 13篇 |
2017年 | 20篇 |
2016年 | 22篇 |
2015年 | 24篇 |
2014年 | 30篇 |
2013年 | 39篇 |
2012年 | 28篇 |
2011年 | 23篇 |
2010年 | 48篇 |
2009年 | 38篇 |
2008年 | 29篇 |
2007年 | 39篇 |
2006年 | 24篇 |
2005年 | 31篇 |
2004年 | 19篇 |
2003年 | 20篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 13篇 |
1999年 | 14篇 |
1998年 | 44篇 |
1997年 | 38篇 |
1996年 | 37篇 |
1995年 | 23篇 |
1994年 | 33篇 |
1993年 | 31篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 7篇 |
1989年 | 22篇 |
1988年 | 18篇 |
1987年 | 18篇 |
1986年 | 12篇 |
1985年 | 8篇 |
1984年 | 7篇 |
1983年 | 15篇 |
1982年 | 17篇 |
1981年 | 10篇 |
1980年 | 15篇 |
1979年 | 4篇 |
1978年 | 7篇 |
1977年 | 14篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1956年 | 3篇 |
排序方式: 共有1006条查询结果,搜索用时 0 毫秒
41.
42.
43.
44.
The extent of length polymorphisms of the heterochromatic and euchromatic segment of the human Y chromosome were investigated in 15 boys with acute leukemia and were compared with 15 normal controls. A greater value of the Yh/F index in relation to controls was established (P < 0.05). The length of the euchromatic segment was also shorter in the patients than the controls (P < 0.05). 相似文献
45.
C. COSTALOS G. RUSSELL Q. AL RAHIM M. J. TARLOW D. J. LLOYD K. R. ROSS 《Acta paediatrica (Oslo, Norway : 1992)》1985,74(3):382-385
ABSTRACT. Serial plasma glucose estimations were performed in 44 light-for-date infants and 17 infants of diabetic mothers fed 2, 3 or 4-hourly with feeds containing 10 % additional carbohydrate in the form of a glucose polymer (Caloreen). In the infants fed 2 and 3-hourly, plasma glucose was higher following the high carbohydrate feeds, particularly immediately before the next feed was due. Given 4-hourly, the high carbohydrate feed had little effect in most light-for-date infants, and in one light-for-date infant and two infants of diabetic mothers the plasma glucose was lower at the end of 4 hours than following normal formula. It is concluded that the addition of glucose polymer to feeds given 2 and 3 hourly has a potentially useful effect in neonates at risk of developing hypoglycaemia, but it cannot be used to increase the feed interval to 4 hours. 相似文献
46.
A series of 73 hypopharyngeal (Zenker's) diverticula is reported and the choice of treatment and technique of excision are discussed. The problems of excision include operation on an infected site with limited access but few patients are unfit for the procedure. Preoperatively the sac should be packed and the oesophagus stented. The side of approach is unimportant as the condition is essentially midline. Cricopharyngeal myotomy appears to reduce the recurrence rate, possibly by improving coordination of pharyngeal contraction and upper oesophageal relaxation. The use of electrocoagulation is not recommended as 20% of patients require repeated general anaesthesia and the procedure fails in 13%. For all but the smallest pouches, excision is the treatment of choice. 相似文献
47.
Stem-cell "plasticity": befuddled by the muddle 总被引:11,自引:0,他引:11
Goodell MA 《Current opinion in hematology》2003,10(3):208-213
In the past 4 years, multiple reports have suggested that stem cells derived from adult tissues can differentiate outside their tissue of origin, challenging long-accepted tenets of developmental biology. This concept of stem-cell "plasticity" has helped to galvanize research on stem cells due to the myriad therapeutic possibilities. However, there are wide discrepancies in the reported frequencies of so-called transdifferentiation events, from recent reports of negative data to reports of the contribution in some tissues and systems reaching as much as 20%. The evidence for and against stem-cell plasticity is reviewed here as well as some of the possible sources of the experimental variation. 相似文献
48.
49.
Background
BCG vaccine is considered to have immunoprophylactic potential in leprosy. However controversy exists about the extent of prophylaxis it provides. In view of this, a study was undertaken to see the evolution of disease in established cases of leprosy who were already vaccinated with BCG and to compare it with the cases of leprosy who were not vaccinated with BCG.Methods
114 newly diagnosed cases of leprosy were studied. Patients were divided into two groups-BCG vaccinated and non-vaccinated. Clinical diagnosis of leprosy was confirmed by bacteriological and histopathological studies in each case. All patients were given standard anti leprosy treatment and were evaluated monthly for a minimum period of one year.Results
All the cases were males in the age group of 20 to 50 years. 25.4% of cases had received BCG vaccine and 74.6% were not vaccinated for the same. No significant difference was observed in the incidence of different types of leprosy in vaccinated and non-vaccinated groups. 25.9% cases in non-vaccinated group developed lepra reaction as compared to 13.8% in vaccinated group. The incidence of deformities and disabilities in vaccinated group was only 10.3% as against 18.8% in non-vaccinated group. The rate of bacillary clearance appeared faster in vaccinated group.Conclusions
Although there is no significant difference in the pattern of different types of leprosy in BCG vaccinated and non-vaccinated cases, there is reduction in the incidence of reactions as well as deformities and disabilities in BCG vaccinated cases as compared to non-vaccinated cases.Key Words: BCG Vaccine, Leprosy 相似文献50.
Background: The recent focus on quality of care and patient safety has been accompanied by increased interest in standardizing the training
for laparoscopic surgeons. Studies have shown that laparoscopic simulators can be used to train surgical skills. Therefore,
we designed an experiment to compare the effectiveness of two popular training systems. One system was based on a physical
model, whereas the other used a virtual reality model.
Methods: A total of 32 medical students and residents were tested on both simulators. Time required for task completion and number
of errors committed were recorded and compared.
Results: The physical training system differentiated among experience levels on three of the five tasks when time was used as a measure
and four of five tasks when score was used, whereas the virtual reality system yielded statistically significant results in
eight of 13 tasks for time and in five of 13 tasks for score.
Conclusion: The physical model is more sensitive than the virtual reality one in detecting differences in levels of laparoscopic surgical
experience. 相似文献