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   1990篇
  免费   186篇
  国内免费   8篇
耳鼻咽喉   4篇
儿科学   86篇
妇产科学   42篇
基础医学   403篇
口腔科学   14篇
临床医学   138篇
内科学   382篇
皮肤病学   21篇
神经病学   90篇
特种医学   199篇
外科学   280篇
综合类   28篇
预防医学   218篇
眼科学   19篇
药学   110篇
肿瘤学   150篇
  2021年   22篇
  2020年   14篇
  2019年   31篇
  2018年   34篇
  2017年   20篇
  2016年   26篇
  2015年   38篇
  2014年   38篇
  2013年   81篇
  2012年   91篇
  2011年   99篇
  2010年   60篇
  2009年   49篇
  2008年   84篇
  2007年   81篇
  2006年   75篇
  2005年   82篇
  2004年   85篇
  2003年   72篇
  2002年   82篇
  2001年   67篇
  2000年   55篇
  1999年   50篇
  1998年   48篇
  1997年   42篇
  1996年   31篇
  1995年   37篇
  1994年   38篇
  1993年   28篇
  1992年   34篇
  1991年   31篇
  1990年   38篇
  1989年   43篇
  1988年   43篇
  1987年   35篇
  1986年   37篇
  1985年   56篇
  1984年   30篇
  1983年   25篇
  1982年   30篇
  1981年   21篇
  1980年   27篇
  1979年   12篇
  1978年   13篇
  1977年   18篇
  1976年   16篇
  1975年   10篇
  1974年   11篇
  1972年   9篇
  1970年   9篇
排序方式: 共有2184条查询结果,搜索用时 15 毫秒
1.
2.
BACKGROUND: Toxic epidermal necrolysis (TEN) is a severe and potentially fatal drug reaction characterized by an extensive skin rash with blisters and exfoliation, frequently accompanied by mucositis. The wounds caused by TEN are similar to second-degree burns and severe cases may involve large areas of skin loss. OBJECTIVES: Analysis of our results in patients with TEN and evaluation of the variety of therapeutic interventions that has been studied and suggested in TEN. PATIENTS/METHODS: Retrospective analysis of 19 consecutive patients with TEN treated in our burns centre between 1989 and 2004. RESULTS: Immediate withdrawal of any potentially fatal drug, maximum supportive care, and a restricted and tailored antibiotic, medical and surgical treatment regimen confined mortality to 21%, whereas prognosis scores like APACHE II and SCORTEN predicted mortality of 22 and 30%, respectively. A positive contribution of selective digestive decontamination is suggested but has yet to be established. CONCLUSIONS: Because of a potentially fatal outcome, fast referral of a patient suspected of TEN to a specialized centre (mostly a burns unit or specialized dermatology centre) for expert wound management and tailored comprehensive care is strongly advised and contributes to survival.  相似文献   
3.
4.
1背景 育龄妇女常见慢性下腹痛,可造成身体损害、情绪忧伤及导致巨大的健康服务费用。美国在这方面的花费超过8亿8千万美元(Mathias 1996)。英国全国数据库的一般性诊治资料显示,慢性下腹痛发病率及流行率与偏头痛、背部痛、哮喘发病率相似(Zondervan 1999)。  相似文献   
5.
The increasing application of Ac-225 for cancer therapy indicates the potential need for its increased production and availability. The production of Ac-225 has been achieved using bremsstrahlung photons from an 18 MV medical linear accelerator (linac) to bombard a Ra-226 target. A linac dose of 2800 Gy produced about 64 microCi of Ra-225, which decays to Ac-225. This result, while consistent with the theoretical calculations, is far too low to be of practical use. A more powerful linac is required that runs at a higher current, longer pulse length and higher frequency for practical production. This process could also lead to the reduction of the nuclear waste product Ra-226.  相似文献   
6.
7.
8.
OBJECTIVE Smoking is a risk factor for the development of thyroid-associated ophthalmopathy, an inflammatory process primarily affecting the fibroblasts in extraocular muscles. We wished to determine whether the extraocular muscle fibroblasts are more sensitive than dermal fibroblasts to T-cell derived cytokines, as a reason for this anatomical localization, and whether hypoxia alters fibroblast function, as one explanation for the susceptibility conferred by smoking. DESIGN Fibroblasts derived from the skin or extraocular muscles of healthy subjects were cultured with cytokines under normal (5% CO2:95% air) and hypoxic (5% C02:95% N2) conditions. MEASUREMENTS Glycosaminoglycan, protein and DNA synthesis were measured by assessing incorporation of d -6-3H-glucosamine, 3H-amino acids, and 3H-thymidine respectively. RESULTS α-lnterferon and interleukin-6 had no effect on fibroblasts, γ-Interferon, tumour necrosis factor and inter-leukin-1 stimulated glycosaminoglycan synthesis; this effect was greater in orbital than in dermal fibroblasts with γ-interferon and interleukin-1 (P<0.05). The same cytokines stimulated total protein with a greater response in orbital fibroblasts with γ-interferon. Interleukin-1 inhibited DNA synthesis in orbital fibroblasts but stimulated DNA synthesis in dermal fibroblasts (P< 0.01); tumour necrosis factor also displayed a differential effect (P<0.01). Hypoxia caused a significant increase in glycosaminoglycan, protein and DNA synthesis in both types of fibroblasts, under both basal and cytokine-treated conditions (P < 0.05). CONCLUSIONS Extraocular muscle fibroblasts respond differently from dermal fibroblasts following cytokine stimulation, which may explain in part the anatomical localization of ophthalmopathy. Hypoxia stimulates fibroblasts and this could contribute, as an enhancing factor, to the adverse effects of smoking on thyroid eye disease.  相似文献   
9.
In this study we test the theory that the presence of the conserved vertebrate telomeric sequence (T(2)AG(3))(n) at the centromeres of Australian marsupial 2n = 14 complements is evidence that these karyotypes are recently derived, which is contrary to the generally held view that the 2n = 14 karyotype is ancestral for Australasian and American marsupials. Here we compare the distribution of the (T(2)AG(3))( n ) sequence and constitutive heterochromatin in the presumed ancestral 2n = 14 complement and in complements with known rearrangements. We found that where there were moderate to large amounts of constitutive heterochromatin, the distribution of the (T(2)AG(3))(n) sequence reflected its presence as a native component of satellite DNA rather than its involvement in past rearrangements. The presence of centromeric heterochromatin in all Australian 2n = 14 complements therefore suggests that centromeric sites of the (T(2)AG(3))(n) sequence do not represent evidence for recent rearrangements.  相似文献   
10.
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