全文获取类型
收费全文 | 2721篇 |
免费 | 389篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 104篇 |
妇产科学 | 36篇 |
基础医学 | 88篇 |
口腔科学 | 66篇 |
临床医学 | 130篇 |
内科学 | 360篇 |
皮肤病学 | 15篇 |
神经病学 | 46篇 |
特种医学 | 146篇 |
外科学 | 116篇 |
综合类 | 13篇 |
预防医学 | 1875篇 |
眼科学 | 8篇 |
药学 | 25篇 |
肿瘤学 | 83篇 |
出版年
2023年 | 32篇 |
2022年 | 51篇 |
2021年 | 33篇 |
2020年 | 96篇 |
2019年 | 29篇 |
2018年 | 99篇 |
2017年 | 102篇 |
2016年 | 104篇 |
2015年 | 90篇 |
2014年 | 94篇 |
2013年 | 166篇 |
2012年 | 40篇 |
2011年 | 37篇 |
2010年 | 114篇 |
2009年 | 132篇 |
2008年 | 66篇 |
2007年 | 60篇 |
2006年 | 74篇 |
2005年 | 55篇 |
2004年 | 46篇 |
2003年 | 28篇 |
2002年 | 87篇 |
2001年 | 91篇 |
2000年 | 57篇 |
1999年 | 135篇 |
1998年 | 157篇 |
1997年 | 194篇 |
1996年 | 206篇 |
1995年 | 130篇 |
1994年 | 55篇 |
1993年 | 121篇 |
1992年 | 18篇 |
1991年 | 11篇 |
1990年 | 15篇 |
1989年 | 31篇 |
1988年 | 31篇 |
1987年 | 23篇 |
1986年 | 29篇 |
1985年 | 21篇 |
1984年 | 11篇 |
1983年 | 16篇 |
1982年 | 15篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 9篇 |
1978年 | 8篇 |
1977年 | 9篇 |
1976年 | 17篇 |
1975年 | 7篇 |
1974年 | 5篇 |
排序方式: 共有3114条查询结果,搜索用时 15 毫秒
81.
82.
Increased Sensitivity of Lymphocytes from Atopic Individuals to Histamine-Induced Suppression 总被引:4,自引:0,他引:4
Histamine depressed lymphocyte reactivity to phytohemagglutinin and, to a lesser degree, concanavalin A, when administered simultaneously with mitogen to lymphocyte cultures. Addition of histamine at later times to the cultures appeared to have a slightly enhancing effect on the lymphocyte response. Stimulation of lymphocytes with pokeweed mitogen was in some cases enhanced, even by high concentrations of histamine. Lymphocytes from atopic individuals were more sensitive to the inhibitory effect of histamine than lymphocytes from nonatopic individuals. The sensitivity appeared age-dependent, but within each age group histamine evoked significantly more suppression on lymphocytes from atopic than from nonatopic individuals. The possibility that the altered reactivity of lymphocytes to histamine, which appears to be associated with atopic allergy, is of pathogenic importance, is discussed, and a hypothesis for the development of atopic disease is proposed. 相似文献
83.
Predominance of null mutations in ataxia-telangiectasia 总被引:15,自引:4,他引:15
Gilad S; Khosravi R; Shkedy D; Uziel T; Ziv Y; Savitsky K; Rotman G; Smith S; Chessa L; Jorgensen TJ; Harnik R; Frydman M; Sanal O; Portnoi S; Goldwicz Z; Jaspers NG; Gatti RA; Lenoir G; Lavin MF; Tatsumi K; Wegner RD; Shiloh Y; Bar-Shira A 《Human molecular genetics》1996,5(4):433-439
Ataxia-telangiectasia (A-T) is an autosomal recessive disorder involving
cerebellar degeneration, immunodeficiency, chromosomal instability,
radiosensitivity and cancer predisposition. The responsible gene, ATM, was
recently identified by positional cloning and found to encode a putative
350 kDa protein with a Pl 3-kinase-like domain, presumably involved in
mediating cell cycle arrest in response to radiation-induced DNA damage.
The nature and location of A-T mutations should provide insight into the
function of the ATM protein and the molecular basis of this pleiotropic
disease. Of 44 A-T mutations identified by us to date, 39 (89%) are
expected to inactivate the ATM protein by truncating it, by abolishing
correct initiation or termination of translation, or by deleting large
segments. Additional mutations are four smaller in-frame deletions and
insertions, and one substitution of a highly conserved amino acid at the Pl
3-kinase domain. The emerging profile of mutations causing A-T is thus
dominated by those expected to completely inactivate the ATM protein. ATM
mutations with milder effects may result in phenotypes related, but not
identical, to A-T.
相似文献
84.
85.
86.
Breast cancer detection: one versus two views 总被引:2,自引:0,他引:2
Mammographic examinations of 169 patients with 172 biopsy-proved carcinomas, and of 194 healthy subjects, were interpreted independently and retrospectively by three experienced mammographers, initially as single-view oblique examinations and 6 months later as two-view oblique-cephalocaudal examinations. For the single-view examinations of the cancer patients, 67% of the cancers were correctly recommended for biopsy, additional views were requested for 23%, and a "negative" interpretation was made for 10%. For the single-view examinations of healthy subjects, biopsy was recommended for 7% and additional views were recommended for 32%. For the two-view examinations of women with cancer, 80% of the cancers were correctly recommended for biopsy, additional views were requested for 4%, and a "negative" interpretation was made for 16%. For two-view examinations of healthy subjects, biopsy was recommended for 7% and additional views were requested for only 5%. The authors conclude that single-view screening should not be performed, because it would lead to an excessive number of "call-back" examinations of healthy patients, producing additional cost and anxiety that would outweigh any theoretical benefit. 相似文献
87.
S. -E. RICKSTEN A. MEDEGÅRD I. CURELARU B. GUSTAVSSON L. E. LINDER 《Acta anaesthesiologica Scandinavica》1986,30(1):13-17
The pressure in the proximal axillary vein (AVP) was compared with central venous pressure (CVP) in eight patients during and after elective abdominal surgery. Both pressures were recorded from soft, elastic, polyurethane catheters inserted in the basilic or cephalic veins ("half-way" catheters), punctured at the fossa cubiti (AVP), and via the right jugular vein (CVP). The AVP and CVP were recorded simultaneously using hydrostatic, conventional disposable venous pressure measurement sets. The measurements were performed during intermittent positive pressure ventilation with positive end-expiratory pressure from 0 to 7.5 cmH2O (0-0.74 kPa), as well as during spontaneous breathing. During both controlled and spontaneous respiration, small mean differences (0.2-1.0 cmH2O) (0.02-0.1 kPa), and a highly significant (P less than 0.001) positive correlation between CVP- and AVP-values were found. An increase of 1 cmH2O (0.10 kPa) in the CVP was associated with an increment of practically identical order (0.99-1.04 cmH2O) (0.10-0.11 kPa) in the AVP. The results suggest that monitoring of the AVP by a basilic "half-way" catheter produces diagnostic information similar to that from the measurement of the CVP from subclavian, external or internal jugular, as well as "long-way" brachial catheter, with no risk of the major mechanical complications which accompany the use of the latter catheters. 相似文献
88.
89.
Diana Cardenas MD PhD Gustavo Díaz RD MSc Jessika Cadavid ND MSC Fernando Lipovestky MD Marisa Canicoba RD Paola Sánchez MD Ludwig Álvarez ND Yan Duarte MD José Guillermo Gutiérrez Reyes MD Gilda Miranda de Noyola RD Claudia Maza RD Sergio Santana Porbén MD Charles Elleri Bermúdez MD Yawelida García RN Isabel Calvo RD Humberto Arenas MD 《JPEN. Journal of parenteral and enteral nutrition》2022,46(1):229-237