全文获取类型
收费全文 | 3581270篇 |
免费 | 264011篇 |
国内免费 | 8746篇 |
专业分类
耳鼻咽喉 | 48915篇 |
儿科学 | 118622篇 |
妇产科学 | 99817篇 |
基础医学 | 503581篇 |
口腔科学 | 102173篇 |
临床医学 | 325207篇 |
内科学 | 697452篇 |
皮肤病学 | 82651篇 |
神经病学 | 293761篇 |
特种医学 | 139397篇 |
外国民族医学 | 1129篇 |
外科学 | 536060篇 |
综合类 | 79316篇 |
现状与发展 | 6篇 |
一般理论 | 1399篇 |
预防医学 | 278679篇 |
眼科学 | 81778篇 |
药学 | 265112篇 |
11篇 | |
中国医学 | 6974篇 |
肿瘤学 | 191987篇 |
出版年
2018年 | 37621篇 |
2017年 | 29141篇 |
2016年 | 33505篇 |
2015年 | 38112篇 |
2014年 | 52425篇 |
2013年 | 79482篇 |
2012年 | 105702篇 |
2011年 | 111683篇 |
2010年 | 67179篇 |
2009年 | 64382篇 |
2008年 | 105111篇 |
2007年 | 111423篇 |
2006年 | 113286篇 |
2005年 | 109102篇 |
2004年 | 105932篇 |
2003年 | 102008篇 |
2002年 | 98870篇 |
2001年 | 167388篇 |
2000年 | 172027篇 |
1999年 | 145572篇 |
1998年 | 42008篇 |
1997年 | 37546篇 |
1996年 | 37574篇 |
1995年 | 36487篇 |
1994年 | 33780篇 |
1993年 | 31729篇 |
1992年 | 116020篇 |
1991年 | 112587篇 |
1990年 | 109326篇 |
1989年 | 105899篇 |
1988年 | 97660篇 |
1987年 | 95943篇 |
1986年 | 90741篇 |
1985年 | 86985篇 |
1984年 | 65120篇 |
1983年 | 55664篇 |
1982年 | 32969篇 |
1981年 | 29628篇 |
1979年 | 59674篇 |
1978年 | 41850篇 |
1977年 | 35550篇 |
1976年 | 33154篇 |
1975年 | 35344篇 |
1974年 | 42329篇 |
1973年 | 40368篇 |
1972年 | 37727篇 |
1971年 | 35249篇 |
1970年 | 32468篇 |
1969年 | 31056篇 |
1968年 | 28385篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
In cystic fibrosis (CF), perturbations of total daily energy expenditure (TDEE) may be a major determinant of altered nutrition and growth. Measurement of TDEE is problematic, though the flex-heart rate method (FHRM) provides a close estimation of TDEE, as compared to the cost-prohibitive, gold standard, the double-labeled water method, and permits estimates of the energy cost of daily activities (ECA) above resting energy expenditure (REE). We hypothesize that alterations in ECA affects TDEE in CF. PURPOSE: To measure components of TDEE in adolescents with CF and normal lung function compared with controls, and to determine whether ECA can be improved by diet and exercise. METHODS: Clinically stable CF subjects (aged 9-13, n=12) and age- and gender-matched controls (n=13) had repeated measurements of TDEE by FHRM, REE, and maximal cardiopulmonary exercise testing (CPET) during a 6-week exercise and diet program. RESULTS: While the mean REE was similar in both groups, ECA was significantly lower in CF adolescents as compared to controls (p=0.02). During CPET, maximal exercise in CF was characterized by hyperventilation, which was unrelated to ventilation-perfusion mismatching. There were no changes in REE after dietary intervention. CONCLUSION: ECA in CF adolescents with normal lung function is lower when compared to healthy controls. These findings support the hypothesis that clinically stable patients with CF have inefficient energy metabolism or alternatively conserve energy during activities of daily living. 相似文献
52.
53.
54.
55.
TG Berger F Kiesewetter C Maczek N Bauer M Lueftl G Schuler M Simon Jr 《Journal of the European Academy of Dermatology and Venereology》2006,20(2):178-183
Vitiligo and psoriasis are both common skin disorders. However, psoriasis strictly confined to pre-existing vitiligo areas is rare and suggests a causal relationship. We report here on two patients with a strict anatomical colocalization of vitiligo and psoriasis. The histopathological examinations showed typical changes for both diseases together with a dense infiltrate of CD4+ and CD8+ T cells. By immunohistochemistry, intracytoplasmatic granzyme B and tumour necrosis factor alpha (TNF-alpha) were detected within the T-cell population, suggesting the functional activity of these cells and the creation of a local T helper 1 (Th1)-cytokine milieu. Additionally, in one patient we could identify anti-melanocytic T cells by tetramer staining and enzyme-linked immunospot (ELISPOT) analysis. These skin-infiltrating lymphocytes might trigger, by the local production of Th-1 cytokines such as TNF-alpha and interferon-gamma (IFN-gamma), the eruption of psoriatic plaques in patients with a genetic predisposition for psoriasis. 相似文献
56.
57.
Effects of poor glucose handling on arterial stiffness and left ventricular mass in normal children.
AIM: Cardiovascular risk factors can be present in children and young adults. We previously found abnormal microvascular function in children who had glucose intolerance and insulin resistance. The aim of the present study was to investigate whether they also have abnormalities in left ventricular mass (LVM) and arterial stiffness. METHODS: We measured heart dimensions and LVM using echocardiography, and arterial stiffness using pulse wave analysis in 23 children with good glucose handling (postfeeding glucose: 3.9 to 5 mmol/L) and 21 with poor glucose handling (7.7 to 11.4 mmol/L). RESULTS: The time to pulse reflection was slightly shorter in the poorer glucose handlers (mean+/-SD: 143+/-10 vs 153+/-20 ms, P=0.04), suggestive of increased arterial stiffness. Also in this group, there were significant relationships between intraventricular septal thickness, blood pressure and body mass index, but not in the normal glucose handlers. CONCLUSIONS: We have found that normal children who are in the lowest quintile of glucose tolerance in comparison with their peers are exhibiting the first signs of arterial stiffening. In addition, we have seen the beginnings of a relationship between blood pressure, body mass index and left ventricular enlargement in this group. While these changes may not yet be clinically significant, their emergence might be further evidence of early predisposition to cardiovascular disease. 相似文献
58.
R C Pattinson L C Snyman A P Macdonald 《Suid-Afrikaanse tydskrif vir geneeskunde》2006,96(11):1191-1194
AIM: To evaluate whether the introduction of a strict protocol approach based on the systemic evaluation of critically ill pregnant women with complications of abortion affected outcome. SETTING: Indigent South Africans managed in the regional and tertiary hospitals of the Pretoria Academic Complex. METHOD: Since 1997 a standard definition of severe acute maternal morbidity (SAMM) has been used in the Pretoria Academic Complex. All cases of SAMM and maternal deaths were entered on the Maternal Morbidity and Mortality Audit System programme. A comparison of outcome of severely ill women who had complications of abortion was made between 1997-1998 (original protocol) and 2002-2004 (strict protocol). OUTCOME MEASURES: The mortality index and prevalence of organ system failure or dysfunction. RESULTS: In 1997-1998 there were 43 women with SAMM who survived and a further 10 maternal deaths due to complications of abortion, compared with 107 women with SAMM and 7 maternal deaths during 2002-2004. The mortality index declined from 18.9% in 1997-1998 to 6.1% in 2002-2004 (p = 0.02, odds ratio 0.28, 95% confidence limits 0.10 - 0.79). Significantly more women had hypovolaemic shock in 2002-2004 compared with 1997-1998 (54.4% v. 35.8%, p = 0.04), but fewer women had immune system failure including septic shock (18.4% v. 47.2%, p = 0.0002) and metabolic dysfunction (0 v. 5.7%, p = 0.03) and there was a trend to less renal failure (10.5% v. 22.6%, p = 0.06) and cardiac failure (4.4% v. 13.2%, p = 0.08). CONCLUSION: The strict protocol approach based on systemic evaluation in managing critically ill pregnant women with complications of abortion, coupled with an intensive, regular feedback mechanism, has been associated with a reduction in the mortality index. 相似文献
59.
60.
A M Carella 《Leukemia》2003,17(6):1199-1200