全文获取类型
收费全文 | 15105篇 |
免费 | 1532篇 |
国内免费 | 108篇 |
专业分类
耳鼻咽喉 | 216篇 |
儿科学 | 229篇 |
妇产科学 | 402篇 |
基础医学 | 952篇 |
口腔科学 | 6737篇 |
临床医学 | 1131篇 |
内科学 | 1807篇 |
皮肤病学 | 142篇 |
神经病学 | 752篇 |
特种医学 | 289篇 |
外科学 | 1550篇 |
综合类 | 226篇 |
一般理论 | 4篇 |
预防医学 | 534篇 |
眼科学 | 181篇 |
药学 | 704篇 |
中国医学 | 83篇 |
肿瘤学 | 806篇 |
出版年
2023年 | 384篇 |
2022年 | 111篇 |
2021年 | 199篇 |
2020年 | 206篇 |
2019年 | 194篇 |
2018年 | 425篇 |
2017年 | 494篇 |
2016年 | 528篇 |
2015年 | 671篇 |
2014年 | 726篇 |
2013年 | 806篇 |
2012年 | 764篇 |
2011年 | 838篇 |
2010年 | 744篇 |
2009年 | 871篇 |
2008年 | 723篇 |
2007年 | 679篇 |
2006年 | 694篇 |
2005年 | 594篇 |
2004年 | 530篇 |
2003年 | 516篇 |
2002年 | 433篇 |
2001年 | 451篇 |
2000年 | 383篇 |
1999年 | 361篇 |
1998年 | 303篇 |
1997年 | 272篇 |
1996年 | 262篇 |
1995年 | 225篇 |
1994年 | 205篇 |
1993年 | 165篇 |
1992年 | 251篇 |
1991年 | 202篇 |
1990年 | 188篇 |
1989年 | 127篇 |
1988年 | 155篇 |
1987年 | 151篇 |
1986年 | 84篇 |
1985年 | 101篇 |
1984年 | 92篇 |
1983年 | 92篇 |
1982年 | 68篇 |
1981年 | 56篇 |
1979年 | 34篇 |
1978年 | 44篇 |
1977年 | 28篇 |
1976年 | 28篇 |
1975年 | 33篇 |
1974年 | 38篇 |
1972年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Shuei-Tu Chen Ko-Hsiu Lu Hai-Lun Sun Wen-Tung Chang Ko-Huang Lue Ming-Chih Chou 《Pediatric allergy and immunology》2006,17(1):49-54
Leukotriene receptor antagonists (LTRAs) were recently added to the method of treating allergic rhinitis (AR). However, in children under 6 yr old, there has been no study about its efficacy in treating AR. We aim to compare the clinical efficacy of montelukast, cetirizine and placebo in the treatment of children from 2 to 6 yr old with perennial allergic rhinitis (PAR), to see if there are any significant differences. Sixty children were selected and treated with montelukast, or cetirizine, or placebo once daily. The efficacy of the three agents was compared with the Pediatric Rhinoconjunctivitis Quality of Life Questionnaire (PRQLQ) and Total Symptom Score (TSS) by diary. In addition, we also examined serum IgE, serum eosinophil cationic protein (ECP), blood eosinophil counts, nasal airway resistance (NAR) and eosinophil percentage in nasal smears. The results revealed that both montelukast and cetirizine were significantly efficacious compared with placebo in NAR, eosinophil percentage in nasal smears, PRQLQ, TSS and all symptom items except nasal itching, throat itching and tearing. For nasal itching, only cetirizine was significantly efficacious. On the other hand, for night sleep quality, montelukast was significantly superior to cetirizine. 相似文献
72.
73.
Denise K Chou Yinzhi Zhao Song Gao Iih-Nan Chou Paul Toselli Phillip Stone Wande Li 《Toxicological sciences》2007,99(1):267-276
To probe mechanisms of cadmium (Cd) damage to the lung extracellular matrix (ECM), we developed Cd-resistant (CdR) rat lung fibroblasts (RFL6) by incubation with graded concentrations of Cd. CdR cells downregulated lysyl oxidase (LO), a copper (Cu)-dependent enzyme essential for crosslinking of collagen and elastin in the ECM, in conjunction with upregulation of other Cu-binding proteins including Cu,Zn-superoxide dismutase (SOD1), copper chaperone for SOD1 (CCS1), metallothionein (MT), and Menkes P-type ATPase (ATP7A), a Cu transporter in the membrane of the Golgi apparatus, as well as gamma-glutamylcysteine synthetase (gamma-GCS), an enzyme for glutathione biosynthesis. Reduction and loss of cytoplasmic distribution of LO in CdR cells were accompanied by its dislocation with the Menkes P-type ATPase and the endoplasmic reticulum marker. CdR cells displayed a defect in LO catalytic activity but an enhancement in Cu,Zn-SOD catalytic activity consistent with the protein expression levels of these enzymes. Although long-term Cd exposure of cells enhanced the Menkes P-type ATPase protein expression, actually, it reduced Cu-dependent catalytic activity of this enzyme in parallel with the deficiency of LO. The low level of 64Cu bound to the LO fraction and the high level of 64Cu bound to the MT fraction provide direct evidence for limitation of Cu bioavailability for LO existing in the CdR cells. These results suggest that downregulation of LO is linked with upregulation of other Cu-binding proteins and with alteration in Cu homeostasis in the CdR phenotype. 相似文献
74.
75.
76.
77.
78.
79.
80.