全文获取类型
收费全文 | 30945篇 |
免费 | 1978篇 |
国内免费 | 1193篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 738篇 |
妇产科学 | 230篇 |
基础医学 | 2223篇 |
口腔科学 | 146篇 |
临床医学 | 3804篇 |
内科学 | 6926篇 |
皮肤病学 | 85篇 |
神经病学 | 702篇 |
特种医学 | 2266篇 |
外国民族医学 | 12篇 |
外科学 | 4793篇 |
综合类 | 5110篇 |
现状与发展 | 4篇 |
预防医学 | 954篇 |
眼科学 | 1064篇 |
药学 | 2468篇 |
11篇 | |
中国医学 | 1211篇 |
肿瘤学 | 1283篇 |
出版年
2024年 | 52篇 |
2023年 | 465篇 |
2022年 | 726篇 |
2021年 | 1047篇 |
2020年 | 954篇 |
2019年 | 958篇 |
2018年 | 864篇 |
2017年 | 1022篇 |
2016年 | 1000篇 |
2015年 | 1055篇 |
2014年 | 1819篇 |
2013年 | 1879篇 |
2012年 | 1752篇 |
2011年 | 1901篇 |
2010年 | 1586篇 |
2009年 | 1649篇 |
2008年 | 1687篇 |
2007年 | 1745篇 |
2006年 | 1579篇 |
2005年 | 1382篇 |
2004年 | 1118篇 |
2003年 | 982篇 |
2002年 | 802篇 |
2001年 | 719篇 |
2000年 | 621篇 |
1999年 | 505篇 |
1998年 | 494篇 |
1997年 | 484篇 |
1996年 | 385篇 |
1995年 | 355篇 |
1994年 | 344篇 |
1993年 | 251篇 |
1992年 | 238篇 |
1991年 | 229篇 |
1990年 | 151篇 |
1989年 | 151篇 |
1988年 | 156篇 |
1987年 | 113篇 |
1986年 | 113篇 |
1985年 | 122篇 |
1984年 | 103篇 |
1983年 | 63篇 |
1982年 | 87篇 |
1981年 | 81篇 |
1980年 | 75篇 |
1979年 | 61篇 |
1978年 | 42篇 |
1977年 | 47篇 |
1976年 | 30篇 |
1975年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Zongzhang Huang Qigu Yao Jianping Zhu Ying He Yanghao Chen Feng Wu Teng Hua 《Diagnostic and interventional imaging》2021,102(5):279-285
PurposeThe purpose of this study was to make a systematic review and meta-analysis to determine the stent diameter (8 mm vs. 10 mm) that conveys better safety and clinical efficacy for transjugular intrahepatic portosystemic shunt (TIPS).Materials and methodsFour databases were used to identify clinical trials published from inception until March 2020. Data were extracted to estimate and compare one-year and three-year overall survivals, hepatic encephalopathy, variceal rebleeding, and shunt dysfunction rates between patients with 8 mm covered stents and those with 10 mm covered stents.ResultsFive eligible studies were selected, which included 489 patients (316 men, 173 women). The 8 mm covered stent group had higher efficacy regarding one-year or three-year overall survival (odds ratio [OR], 2.88; P = 0.003) and (OR, 1.81; P = 0.04) and lower hepatic encephalopathy (OR, 0.69; P = 0.04) compared with 10 mm covered stent group. There were no significant differences in variceal rebleeding rate (OR 0.80; P = 0.67). However, shunt dysfunction was lower in 10 mm covered stent group (OR, 2.26; P = 0.003).ConclusionsOur results suggest that the use of 8 mm covered stents should be preferred to that of 10 mm covered stents for TIPS placement when portal pressure is frequently monitored. 相似文献
2.
Gut bacteria and gut barrier plays important roles in body homeostasis. Ciprofloxacin (CPFX) is widely used to treat bacterial infections. However, whether high dosage of CPFX has side effects on gut barrier integrity is still unclear. Our results indicated that the High CPFX treatment (1 mg/ml) caused weight loss, nervousness, anorexia, and increased apoptosis cells in gut, but less influence was observed in the Low CPFX group (0.2 mg/ml). Meanwhile, the High CPFX treatment impaired tight junction molecules Ocln/ZO-1 level and down-regulated antibacterial genes expression (reg3γ, pla2g2α and defb1). Further, the High CPFX treatment increased pro-inflammatory cytokine IL-1β in intestinal tract, decreased IL-17A of duodenum but increased IL-17A of colon at day 37. In addition, the gut bacterial diversity and richness behaved significantly loss regarding CPFX treatment, especially in the High CPFX group during the experiment. Indole exhibited sharply decline in both Low and High CPFX groups at day 7, and the High CPFX mice needed longer time on restoring indole level. Meanwhile, CPFX treatment strongly decreased the concentrations of butyric acid and valeric acid at day 1. Correlation analysis indicated that the linked patterns between the key bacteria (families Bacteroidales_S247, Ruminococcaceae and Desulfovibrionaceae) and metabolites (indole and butyric acid) were disturbed via the CPFX treatment. In conclusion, the High CPFX treatment impaired the gut barrier with the evidence of reduced expression of tight junction proteins, increased apoptosis cells and inflammatory cells, decreased the bacterial diversity and composition, which suggesting a proper antibiotic-dosage use should be carefully considered in disease treatment. 相似文献
3.
4.
5.
6.
《The Journal of thoracic and cardiovascular surgery》2023,165(2):449-459.e4
ObjectiveThe objective of this study was to investigate the association between morphological variation and postsurgical pulmonary vein (PV) stenosis (PPVS) in patients with cardiac total anomalous pulmonary venous connection (TAPVC).MethodsThis single-center, retrospective study included 168 pediatric patients who underwent surgical repair of cardiac TAPVC from 2013 to 2019 (connection to the coronary sinus [CS], n = 136; connection directly to the right atrium [RA], n = 32). Three-dimensional computed tomography modeling and geometric analysis were performed to investigate the morphological features; their relevance to the PPVS was examined.ResultsThe connection type had no association with PPVS (CS type: 18% vs right atrial type: 19%; P = .89) but there was a higher incidence of PPVS in patients with a single PV orifice than > 1 orifice (P < .001). Confluence-to-total PV area ratio (hazard ratio, 4.78, 95% CI, 1.86-12.32; P = .001) and length of drainage route (hazard ratio, 1.22; 95% CI, 1.14-1.31; P < .001) had a 4- and 1-fold increase in the risk for PPVS in the CS type after adjustment for age and preoperative pulmonary venous obstruction. In the right atrial type, those with anomalous PV return to the RA roof were more likely to develop PPVS than to the posterior wall of the RA (P < .001).ConclusionsThe number of inter-junction PV orifice correlated with PPVS development in cardiac TAPVC. The confluence-to-total PV ratio, length of drainage route, and anomalous PV return to the RA roof are important predictors for PPVS. Morphological subcategorization in this clinical setting can potentially assist in surgical decision-making. 相似文献
7.
This study evaluated the genetic variation of 17 autosomal short tandem repeat (STR) loci included in the PowerPlex® 18D Kit. Samples of 562 unrelated healthy Lahu individuals living in Yunnan Province in southwestern China were investigated. The data were analyzed to provide information on allele frequencies and other statistical parameters relevant to the forensic population. Of the 17 loci, 16 reached the Hardy–Weinberg equilibrium after Bonferroni correction. A total of 176 alleles were identified in 17 STR loci, and allele frequencies ranged from 0.000 890 to 0.578 292. The combined discrimination power (CPD) and probability of excluding paternity (CPE) of the 17 STR loci were 0.999 999 999 999 999 999 489 and 0.999 998 301 753 122. The genetic relationships among 28 populations were also estimated. 相似文献
8.
9.
10.