全文获取类型
收费全文 | 23476篇 |
免费 | 1835篇 |
国内免费 | 711篇 |
专业分类
耳鼻咽喉 | 60篇 |
儿科学 | 749篇 |
妇产科学 | 578篇 |
基础医学 | 1632篇 |
口腔科学 | 90篇 |
临床医学 | 2327篇 |
内科学 | 8228篇 |
皮肤病学 | 105篇 |
神经病学 | 665篇 |
特种医学 | 271篇 |
外国民族医学 | 1篇 |
外科学 | 1734篇 |
综合类 | 3382篇 |
现状与发展 | 4篇 |
预防医学 | 1343篇 |
眼科学 | 92篇 |
药学 | 3359篇 |
11篇 | |
中国医学 | 1060篇 |
肿瘤学 | 331篇 |
出版年
2023年 | 301篇 |
2022年 | 300篇 |
2021年 | 691篇 |
2020年 | 703篇 |
2019年 | 707篇 |
2018年 | 745篇 |
2017年 | 755篇 |
2016年 | 725篇 |
2015年 | 765篇 |
2014年 | 1305篇 |
2013年 | 1965篇 |
2012年 | 1395篇 |
2011年 | 1473篇 |
2010年 | 1178篇 |
2009年 | 1148篇 |
2008年 | 1173篇 |
2007年 | 1165篇 |
2006年 | 966篇 |
2005年 | 811篇 |
2004年 | 796篇 |
2003年 | 765篇 |
2002年 | 617篇 |
2001年 | 548篇 |
2000年 | 508篇 |
1999年 | 417篇 |
1998年 | 316篇 |
1997年 | 348篇 |
1996年 | 251篇 |
1995年 | 238篇 |
1994年 | 218篇 |
1993年 | 203篇 |
1992年 | 181篇 |
1991年 | 159篇 |
1990年 | 119篇 |
1989年 | 138篇 |
1988年 | 142篇 |
1987年 | 143篇 |
1986年 | 123篇 |
1985年 | 160篇 |
1984年 | 152篇 |
1983年 | 83篇 |
1982年 | 136篇 |
1981年 | 125篇 |
1980年 | 140篇 |
1979年 | 113篇 |
1978年 | 92篇 |
1977年 | 82篇 |
1976年 | 73篇 |
1973年 | 68篇 |
1970年 | 46篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Qiangsheng He Chongfei Huang Xiwen Qin Yuanyuan Yu Di Tang Junjie Huang Zi Chong Kuo Yuyao Ling Deli Mao Bin Xia Wenjing Li Kuiqing Lu Man Yang Yulong He Wenbo Meng Jinqiu Yuan Yihang Pan 《International journal of cancer. Journal international du cancer》2023,153(5):942-949
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes. 相似文献
12.
Omid Asbaghi Behzad Nazarian
eljko Reiner Elaheh Amirani Fariba Kolahdooz Maryam Chamani Zatollah Asemi 《Phytotherapy research : PTR》2020,34(2):239-253
The aim of this systematic review and meta‐analysis was to analyze the effects of grape seed extract (GSE) on glycemic control and serum lipoproteins, inflammation and body weight. Two independent authors systematically searched online databases including EMBASE, Scopus, PubMed, Cochrane Library, and Web of Science from inception until May 30, 2019. Cochrane Collaboration risk of bias tool was applied to assess the methodological quality of included trials. The heterogeneity among the included studies was assessed using Cochrane's Q test and I‐square (I2) statistic. Data were pooled using a random‐effects model and weighted mean difference (WMD) was considered as the overall effect size. Fifty trials were included in this meta‐analysis. Pooling effect sizes from studies demonstrated a significant decrease in fasting plasma glucose (FPG) (WMD): ?2.01; 95% confidence interval (CI): ?3.14, ?0.86), total cholesterol (TC; WMD: ?6.03; 95% CI: ?9.71, ?2.35), low‐density lipoprotein (LDL) cholesterol (WMD: ?4.97; 95% CI: ?8.37, ?1.57), triglycerides (WMD: ?6.55; 95% CI: ?9.28, ?3.83), and C‐reactive protein (CRP) concentrations (WMD: ?0.81; 95% CI: ?1.25, ?0.38) following GSE therapy. Grape seed did not influence HbA1c, HDL cholesterol levels, and anthropometric measurements. This meta‐analysis demonstrated that GSE intake significantly reduced FPG, TC, LDL cholesterol, triglycerides, and CRP levels. 相似文献
13.
目的以肠道微生态为切入点探讨补肾化浊方联合粪菌移植治疗多囊卵巢综合征(PCOS)潜在机制。方法将30只6周龄SD大鼠随机分为空白组、模型组、中药组、粪菌移植组、中药+粪菌移植组,每组6只。来曲唑1 mg/(kg d)灌胃51 d,第22日起,中药组加灌补肾化浊方21.7 g/(kg d),粪菌移植组加灌新鲜粪便2 g/(kg d),中药+粪菌移植组加灌补肾化浊方21.7 g/(kg d)和新鲜粪便2 g/(kg d),连续30 d,另设空白组。干预结束后,腹主动脉取血检测大鼠血清性激素、空腹胰岛素(FINS)、空腹血糖(FPG),ELISA检测大鼠血清白细胞介素(IL)-18、肿瘤坏死因子-α(TNF-α)水平,HE染色观察大鼠卵巢形态学变化。结果与空白组比较,模型组大鼠卵巢呈多囊样改变,体质量、睾酮、黄体生成素(LH)/促卵泡激素(FSH)、FPG、HOMA-IR、IL-18、TNF-α水平均明显升高(P<0.01,P<0.001);与模型组比较,中药+粪菌移植组可显著改善上述指标(P<0.05,P<0.01,P<0.001),中药组可显著改善除TNF-α外各项指标(P<0.05,P<0.01),粪菌移植组可显著降低PCOS大鼠LH/FSH、IL-18水平(P<0.01,P<0.001);在降低IL-18水平方面,中药+粪菌移植组作用显著优于中药组(P<0.01)。结论中药联合粪菌移植可显著改善PCOS大鼠生殖和代谢功能,改善慢性炎症状态。 相似文献
14.
15.
M. Batliner M. Weiss S. A. Dual B. Grass M. Meboldt M. Schmid Daners 《Anaesthesia》2019,74(11):1425-1431
Syringe infusion pumps are used for the administration of short-acting drugs in anaesthesia and critical care medicine, but are prone to flow irregularities at low flow rates. A flow-controlled syringe infusion pump using an integrated flow sensor for feedback control represents a new approach to overcoming these limitations. This study compares the performance of a prototype flow-controlled syringe pump both at start-up, and during vertical displacement manoeuvres, with that of a standard infusion syringe pump. The novel pump almost completely eliminated delays at start-up and flow irregularities during hydrostatic pressure changes. Related fluctuations in plasma drug concentration were minimised and the known disadvantages of standard syringe infusion pumps currently used in clinical practice were reduced. Besides providing fast start-up to steady-state flow and precise continuous drug delivery at low flow rates during hydrostatic pressure changes, the new pump offers the potential for the development of target-controlled infusion algorithms for short-acting cardiovascular and other drugs. 相似文献
16.
17.
18.
19.
20.