全文获取类型
收费全文 | 8975篇 |
免费 | 555篇 |
国内免费 | 157篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 152篇 |
妇产科学 | 104篇 |
基础医学 | 1316篇 |
口腔科学 | 181篇 |
临床医学 | 761篇 |
内科学 | 1867篇 |
皮肤病学 | 192篇 |
神经病学 | 583篇 |
特种医学 | 611篇 |
外国民族医学 | 2篇 |
外科学 | 1291篇 |
综合类 | 170篇 |
预防医学 | 591篇 |
眼科学 | 232篇 |
药学 | 756篇 |
1篇 | |
中国医学 | 151篇 |
肿瘤学 | 606篇 |
出版年
2023年 | 79篇 |
2022年 | 278篇 |
2021年 | 376篇 |
2020年 | 181篇 |
2019年 | 256篇 |
2018年 | 271篇 |
2017年 | 200篇 |
2016年 | 315篇 |
2015年 | 402篇 |
2014年 | 485篇 |
2013年 | 545篇 |
2012年 | 871篇 |
2011年 | 759篇 |
2010年 | 381篇 |
2009年 | 359篇 |
2008年 | 542篇 |
2007年 | 446篇 |
2006年 | 436篇 |
2005年 | 361篇 |
2004年 | 336篇 |
2003年 | 335篇 |
2002年 | 269篇 |
2001年 | 180篇 |
2000年 | 167篇 |
1999年 | 149篇 |
1998年 | 77篇 |
1997年 | 50篇 |
1996年 | 46篇 |
1995年 | 38篇 |
1994年 | 24篇 |
1993年 | 25篇 |
1992年 | 32篇 |
1991年 | 42篇 |
1990年 | 25篇 |
1989年 | 28篇 |
1988年 | 30篇 |
1987年 | 25篇 |
1986年 | 26篇 |
1985年 | 26篇 |
1984年 | 17篇 |
1983年 | 21篇 |
1982年 | 15篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 17篇 |
1978年 | 11篇 |
1976年 | 10篇 |
1974年 | 9篇 |
1970年 | 12篇 |
1968年 | 9篇 |
排序方式: 共有9687条查询结果,搜索用时 0 毫秒
21.
E. Imhof S. Elsasser B. Rosmus H. R. Ha F. Follath A. P. Perruchoud 《European journal of clinical pharmacology》1991,41(4):317-319
Summary A single oral dose of verapamil 80 mg was shown significantly to inhibit histamine-induced bronchoconstriction in 8 out of 16 asthmatic subjects (maximum increase in PD20FEVHi 416%). There was still significant protection ( PD20FEV1Hi>100%) in the responders 5 h after the oral dose. The relationship of the bronchoprotective effect to the plasma level of verapamil was also examined. Responders and non-responders did not differ significantly in the peak plasma level or the time course of the plasma verapamil concentration.The protective effect was not correlated with the peak plasma level of verapamil or with the baseline bronchial hyperreactivity. 相似文献
23.
Lung involvement in Langerhans' cell histiocytosis: prevalence, clinical features, and outcome. 总被引:1,自引:0,他引:1
In Langerhans' cell histiocytosis, the prognostic significance of pulmonary disease is controversial. The clinical and radiological features and lung function tests of Langerhans' cell histiocytosis patients presenting to a single tertiary referral center between 1981 and 1987 were reviewed. Age at diagnosis ranged from 2 weeks to 16 years (median 1.7 years) and the male-female ratio was 2.4:1. No child presented with lung involvement alone. In 18 (40%) of 45 patients with multisystem disease there was clinical and/or radiological evidence of lung pathology. Another 6 children (13%) with normal chest roentgenograms had abnormal lung function tests, suggesting subclinical ("occult") involvement. Those with overt lung disease tended to present at a younger than average age (median 0.6 years). The most common functional disturbance was reduced lung or respiratory compliance with reduced lung volumes. Patients with and without lung involvement showed a similar pattern of involvement of other organs, with skin and bone most commonly affected. Of the 45 children with multisystem disease, 38 (84%) survived 2 to 7 years after diagnosis; there was a similar proportion of deaths in children with and without lung involvement. It is concluded that lung involvement occurs in nearly half of young children with multisystem Langerhans' cell histiocytosis but does not adversely affect outcome. 相似文献
24.
M Go?ebiowska I Ligenza I Kobierska E Zielińska J Wlaz?owski P Sikora K Ha?adaj 《Ginekologia polska》1992,63(5):221-226
1110 neonates, from 30 to 42 of estimated gestational age (EGA) were measured on the 1st day of life to estimate upper mid-arm circumference (MAC) and head circumference (HC). Individual MAC/HC ratio was calculated. MAC/HC ratio was used to estimate gestational age and nutritional status of the newborns. We proved that MAC/HC ratio increased linearly between 30 and 38 week of pregnancy and it stabilized between 38-42 week. We compared MAC/HC ratio with birth weight, skin fold score, and ponderal index. We concluded that this ratio may be very useful to estimate gestational age and to include the neonates to "the group of risk". 相似文献
25.
Poly(ADP-ribose) polymerase-1 (PARP-1) is a nuclear enzyme, activated by DNA strand breaks to participate in DNA repair. Overactivation of PARP by cellular insults depletes its substrate NAD(+) and then ATP, leading to a major energy deficit and cell death. This mechanism appears to be prominent in vascular stroke and other neurodegenerative processes in which PARP gene deletion and PARP-inhibiting drugs provide major protection. Cell death associated with PARP-1 overactivation appears to be predominantly necrotic while apoptosis is associated with PARP-1 cleavage, which may conserve energy needed for the apoptotic process. Novel forms of PARP derived from distinct genes and lacking classic DNA-binding domains may have nonnuclear functions, perhaps linked to cellular energy dynamics. 相似文献
26.
27.
28.
Vascular endothelial growth factor gene polymorphisms and risk of primary lung cancer. 总被引:17,自引:0,他引:17
Su Jeong Lee Sin Yeob Lee Hyo-Sung Jeon Sun Ha Park Jin Sung Jang Ga Young Lee Ji Woong Son Chang Ho Kim Won Kee Lee Sin Kam Rang Woon Park Tae-In Park Young Mo Kang In-San Kim Tae Hoon Jung Jae Yong Park 《Cancer epidemiology, biomarkers & prevention》2005,14(3):571-575
Angiogenesis is an essential process in the development, growth, and metastasis of malignant tumors including lung cancer. DNA sequence variations in the vascular endothelial growth factor (VEGF) gene may lead to altered VEGF production and/or activity, thereby causing interindividual differences in the susceptibility to lung cancer via their actions on the pathways of tumor angiogenesis. To test this hypothesis, we investigated the potential association between three VEGF polymorphisms (-460T > C, +405C > G, and 936C > T)/haplotypes and the risk of lung cancer in a Korean population. VEGF genotypes were determined in 432 lung cancer patients and 432 healthy controls that were frequency matched for age and sex. VEGF haplotypes were predicted using Bayesian algorithm in the phase program. Compared with the combined +405 CC and CG genotype, the +405 GG genotype found associated with a significantly decreased risk of small cell carcinoma [SCC; adjusted odds ratio (OR), 0.36; 95% confidence interval (95% CI), 0.17-0.78]. The 936 CT genotype and the combined 936 CT and TT genotype were also associated with a significantly decreased risk of SCC compared with the 936 CC genotype (adjusted OR, 0.47; 95% CI, 0.26-0.85 and adjusted OR, 0.44; 95% CI, 0.24-0.80, respectively). Haplotype CGT was associated with a significantly decreased risk of SCC (adjusted OR, 0.39; 95% CI, 0.18-0.87), whereas haplotype TCC conferred a significantly increased risk of SCC (adjusted OR, 1.63; 95% CI, 1.14-2.33). None of the VEGF polymorphisms studied significantly influenced the susceptibility to lung cancer except SCC. However, haplotypes TCT and TGT were significantly associated with the risk of overall lung cancer, respectively (adjusted OR, 0.38; 95% CI, 0.25-0.60 and adjusted OR, 3.94; 95% CI, 2.00-7.76, respectively). These effects of haplotypes TCT and TGT on lung cancer risk were observed in three major histologic types of lung cancer. These results suggest that the VEGF gene may be contribute to an inherited predisposition to lung cancer. 相似文献
29.