全文获取类型
收费全文 | 1759篇 |
免费 | 133篇 |
国内免费 | 25篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 62篇 |
妇产科学 | 26篇 |
基础医学 | 283篇 |
口腔科学 | 34篇 |
临床医学 | 172篇 |
内科学 | 344篇 |
皮肤病学 | 48篇 |
神经病学 | 211篇 |
特种医学 | 45篇 |
外科学 | 142篇 |
综合类 | 38篇 |
预防医学 | 96篇 |
眼科学 | 43篇 |
药学 | 160篇 |
中国医学 | 4篇 |
肿瘤学 | 202篇 |
出版年
2023年 | 12篇 |
2022年 | 29篇 |
2021年 | 48篇 |
2020年 | 22篇 |
2019年 | 37篇 |
2018年 | 50篇 |
2017年 | 30篇 |
2016年 | 33篇 |
2015年 | 37篇 |
2014年 | 43篇 |
2013年 | 71篇 |
2012年 | 126篇 |
2011年 | 126篇 |
2010年 | 67篇 |
2009年 | 51篇 |
2008年 | 79篇 |
2007年 | 106篇 |
2006年 | 53篇 |
2005年 | 63篇 |
2004年 | 75篇 |
2003年 | 67篇 |
2002年 | 56篇 |
2001年 | 45篇 |
2000年 | 34篇 |
1999年 | 43篇 |
1998年 | 25篇 |
1997年 | 18篇 |
1996年 | 22篇 |
1995年 | 19篇 |
1994年 | 19篇 |
1993年 | 15篇 |
1992年 | 34篇 |
1991年 | 21篇 |
1990年 | 21篇 |
1989年 | 22篇 |
1988年 | 19篇 |
1987年 | 23篇 |
1986年 | 23篇 |
1985年 | 21篇 |
1984年 | 26篇 |
1983年 | 22篇 |
1982年 | 17篇 |
1981年 | 17篇 |
1979年 | 25篇 |
1978年 | 10篇 |
1977年 | 8篇 |
1974年 | 7篇 |
1973年 | 9篇 |
1972年 | 8篇 |
1968年 | 7篇 |
排序方式: 共有1917条查询结果,搜索用时 0 毫秒
41.
42.
43.
DNA methylation patterns of the gamma delta beta-globin genes in human fetal and adult erythroid tissues. 总被引:1,自引:0,他引:1
An investigation of the correlation between the gamma----beta-globin switch and DNA methylation was carried out. The restriction patterns obtained with methylation-sensitive and -insensitive enzymes indicated hypomethylation in the promoter region of the gamma-globin genes in fetal liver DNA but high methylation of the same region in all other samples (except in the presence of an elevated erythroblast count or leukemia). All samples appeared to be partially hypomethylated at the 5' end of the delta-globin gene and hypomethylated at the 3' region of the beta-globin gene. Although consistent with a role for DNA methylation in globin gene regulation, the results also suggest that other factors besides methylation may be required for regulation of the level of expression, and switching of the globin genes. 相似文献
44.
S Kohl M S West C G Prober W M Sullender L S Loo A M Arvin 《The Journal of infectious diseases》1989,160(5):770-776
The role of antiviral antibodies in protection against neonatal herpes simplex virus (HSV) infection remains controversial. The relationship between neonatal and maternal anti-HSV antibodies and disease presentation was analyzed in 47 babies. Of the neonates, 77% had localized and 23% had disseminated HSV infection. Antibody-dependent cellular cytotoxic (ADCC) antibodies were evaluated in comparison with HSV neutralizing antibodies. High maternal (greater than 1:10(4)) or neonatal (greater than 1:10(3)) anti-HSV ADCC antibody levels or high neonatal antiviral neutralizing levels (greater than 1:20) were independently associated with an absence of disseminated HSV infection. Cochran-Mantel-Haenszel analysis demonstrated that ADCC levels were associated with disease status (P less than .02) while controlling for the level of neutralizing antibody. 相似文献
45.
van den Berg WB Joosten LA Kollias G van De Loo FA 《Annals of the rheumatic diseases》1999,58(Z1):I40-I48
Chronic arthritis is characterised by persistent joint inflammation and concomitant joint destruction. Using murine arthritis models and neutralising antibodies as well as cytokine specific knockout conditions, it was found that tumour necrosis factor alpha (TNFalpha) is important in early joint swelling. Membrane bound TNFalpha is sufficient to drive this aspect of inflammation as well as the acute cellular infiltrate in the synovial tissue. Interleukin 1 (IL1) is not necessarily a dominant cytokine in early joint swelling, but has a pivotal role in sustained cellular infiltration and erosive cartilage damage. TNFalpha independent IL1 production is a prominent feature in murine arthritis models. These observations provide evidence for potential uncoupling of joint inflammation and erosive changes, implying that both cytokines need to be targeted to achieve optimal treatment. 相似文献
46.
D. Urbanitz Th. Büchner D. Kamanabroo W. Hiddemann H. Schulte J. van de Loo 《Annals of hematology》1981,43(2):129-133
Summary Sixty patients with ANLL were given intensified remission induction therapy consisting of thioguanine, cytosine arabinoside and daunorubicin (TAD). The mean age of patients was 47.6 years (range 18 to 74 years). Basing on leukemic cell kinetic data time sequencing of drugs was different from the original TAD protocol. Complete remission (CR) was achieved in 43/60 patients (72%) with 10 CR in 15 patients over 60 years of age. Seventy-nine percent of the CR were induced by one cycle vs. thirty percent reported from the original TAD regimen. The major cause of induction failure — in ten of the 60 patients — was thrombocytopenia refractory to platelet transfusions. Persisting leukemia after two induction cycles was documented in only two patients. Median remission duration by life table analysis is 10 months with 17 patients in continuous CR for 1+ to 22+ months.Supported by a grant (BU 210/7) of the Deutsche Forschungsgemeinschaft 相似文献
47.
Noor H. A. Suaini Evelyn Xiu-Ling Loo Rachel L. Peters Gaik Chin Yap Katrina J. Allen Hugo Van Bever David J. Martino Anne Eng Neo Goh Shyamali C. Dharmage Marjorelee T. Colega Mary Foong Fong Chong Anne-Louise Ponsonby Kok Hian Tan Mimi L. K. Tang Keith M. Godfrey Bee Wah Lee Lynette Pei-Chi Shek Jennifer J. Koplin Elizabeth Huiwen Tham 《Allergy》2021,76(10):3171-3182
48.
49.
The effect of a forced‐air warming blanket on patients' end‐tidal and transcutaneous carbon dioxide partial pressures during eye surgery under local anaesthesia: a single‐blind,randomised controlled trial 下载免费PDF全文
Surgical drapes used during eye surgery are impermeable to air and hence risk trapping air underneath them. We investigated the effect of a forced‐air warming blanket on carbon dioxide accumulation under the drapes in patients undergoing eye surgery under local anaesthesia without sedation. Forty patients of ASA physical status 1 and 2 were randomly assigned to either the forced‐air warmer (n = 20) or a control heated overblanket (n = 20). All patients were given 1 l.min?1 oxygen. We measured transcutaneous and end‐tidal carbon dioxide partial pressures, heart rate, arterial pressure, respiratory rate, temperature and oxygen saturation before and after draping, then every 5 min thereafter for 30 min. The mean (SD) transcutaneous carbon dioxide partial pressure in the forced‐air warming group stayed constant after draping at 5.7 (0.2) kPa but rose to a maximum of 6.4 (0.4) kPa in the heated overblanket group (p = 0.0001 for the difference at time points 15 min and later). We conclude that forced‐air warming reduces carbon dioxide accumulation under the drapes in patients undergoing eye surgery under local anaesthesia. 相似文献
50.
Meera Thalayasingam Evelyn Xiu Ling Loo Michelle Meiling Tan Hugo Van Bever Lynette Pei-Chi Shek 《Singapore medical journal》2015,56(11):622-625