全文获取类型
收费全文 | 9982篇 |
免费 | 608篇 |
国内免费 | 235篇 |
专业分类
耳鼻咽喉 | 207篇 |
儿科学 | 99篇 |
妇产科学 | 50篇 |
基础医学 | 1823篇 |
口腔科学 | 178篇 |
临床医学 | 972篇 |
内科学 | 2464篇 |
皮肤病学 | 371篇 |
神经病学 | 733篇 |
特种医学 | 556篇 |
外科学 | 995篇 |
综合类 | 89篇 |
现状与发展 | 1篇 |
预防医学 | 365篇 |
眼科学 | 118篇 |
药学 | 963篇 |
中国医学 | 172篇 |
肿瘤学 | 669篇 |
出版年
2024年 | 7篇 |
2023年 | 88篇 |
2022年 | 309篇 |
2021年 | 494篇 |
2020年 | 213篇 |
2019年 | 272篇 |
2018年 | 320篇 |
2017年 | 233篇 |
2016年 | 358篇 |
2015年 | 471篇 |
2014年 | 576篇 |
2013年 | 622篇 |
2012年 | 1053篇 |
2011年 | 935篇 |
2010年 | 507篇 |
2009年 | 410篇 |
2008年 | 522篇 |
2007年 | 544篇 |
2006年 | 411篇 |
2005年 | 396篇 |
2004年 | 277篇 |
2003年 | 268篇 |
2002年 | 233篇 |
2001年 | 188篇 |
2000年 | 180篇 |
1999年 | 139篇 |
1998年 | 100篇 |
1997年 | 91篇 |
1996年 | 74篇 |
1995年 | 51篇 |
1994年 | 53篇 |
1993年 | 36篇 |
1992年 | 35篇 |
1991年 | 29篇 |
1990年 | 32篇 |
1989年 | 46篇 |
1988年 | 43篇 |
1987年 | 30篇 |
1986年 | 30篇 |
1985年 | 25篇 |
1984年 | 19篇 |
1983年 | 11篇 |
1982年 | 17篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 8篇 |
1978年 | 5篇 |
1977年 | 6篇 |
1976年 | 10篇 |
1975年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
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
52.
53.
54.
55.
Jun-Pil Jang Gil Soo Kim Tae Hoon Oh Beomcheol Park Minhee Kim Gwi Ja Hwang Hyeok-Won Lee Jin-Gyeom Lee Young-Soo Hong Jong Seog Ahn Sung-Kyun Ko Jae-Hyuk Jang 《RSC advances》2022,12(35):22360
Two new polyketide glycosides jejuketomycins A (1) and B (2), were isolated from a culture of Streptomyces sp. KCB15JA151. Their chemical structures including the absolute configurations were determined by detailed analyses of the NMR and HRMS data and ECD calculations and spectral data. Compounds 1 and 2 possess an unusual 6/6/8 tricyclic ring system. Biological evaluation with the wound healing assay and time-lapse cell tracking analysis revealed that compounds 1 and 2 have significant inhibitory activities against cancer cell migration with low cytotoxicity.Two new polyketide glycosides jejuketomycins A (1) and B (2), were isolated from a culture of Streptomyces sp. KCB15JA151. 相似文献
56.
Jong-Wook Yoo Yoon-Jung Shin Xiaoyang Ma Young-Hoo Son Hyo-Min Jang Chang Kyun Lee Dong-Hyun Kim 《Nutrients》2022,14(10)
Gut microbiota dysbiosis is strongly associated with psychiatric disorders and inflammatory bowel disease (IBD). Herein, we examined whether the fecal microbiota of IBD patients with depression (IBDD) and their gut microbiota culture (iGm) could cause depression and colitis in mice and anti-inflammatory probiotics could mitigate depression in iGm-transplanted or immobilization stress (IS)-exposed mice. Fecal microbiota transplantation (FMT) from IBDD patients, which exhibited Enterobacteriaceae-rich gut microbiota, and its gut microbiota culture (iGm) increased depression-like behaviors in mice. Their treatments heightened the blood lipopolysaccharide (LPS) level and colonic IL-1β and IL-6 expression. However, FMT from healthy volunteers or sulfasalazine treatment alleviated cGm-induced depressive-like behaviors and hippocampal and colonic inflammation in mice. Moreover, oral administration of Lactobacillus plantarum NK151, Bifidobacterium longum NK173, and Bifidobacterium bifidum NK175, which inhibited LPS-induced IL-6 expression in macrophages, alleviated cGm-induced depression-like behaviors, hippocampal NF-κB+Iba1+ cell numbers and IL-1β and IL-6 expression, blood LPS, IL-6, and creatinine levels, and colonic NF-κB+CD11c+ number and IL-1β and IL-6 expression in mice. Treatment with NK151, NK173, or NK175 mitigated immobilization stress (IS)-induced depressive-like behaviors, neuroinflammation, and gut inflammation in mice. NK151, NK173, or NK175 also decreased IS-induced blood LPS, IL-6, and creatinine levels. The transplantation of Enterobacteriaceae-rich gut microbiota can cause depression and colitis, as IS exposure, and anti-inflammatory NK151, NK173, and NK175, may alleviate stress-induced fatigue, depression, and colitis by regulating the expression of proinflammatory and anti-inflammatory cytokines through the suppression of gut bacterial LPS. 相似文献
57.
Hyohun Choi Jang Hoon Lee Hyuk Kyoon Park Eunkyu Lee Myeong Seop Kim Hyeon Jeong Kim Bo Eun Park Hong Nyun Kim Namkyun Kim Se Yong Jang Myung Hwan Bae Dong Heon Yang Hun Sik Park Yongkeun Cho 《Journal of Korean medical science》2022,37(21)
BackgroundIt has been known that the fear of contagion during the coronavirus disease 2019 (COVID-19) creates time delays with subsequent impact on mortality in patients with acute myocardial infarction (AMI). However, difference of time delay and clinical outcome in patients with ST-segment elevation myocardial infarction (STEMI) or non-STEMI between the COVID-19 pandemic and pre-pandemic era has not been fully investigated yet in Korea. The aim of this study was to investigate the impact of COVID-19 pandemic on time delays and clinical outcome in patients with STEMI or non-STEMI compared to the same period years prior.MethodsA total of 598 patients with STEMI (n = 195) or non-STEMI (n = 403) who underwent coronary angiography during the COVID-19 pandemic (February 1 to April 30, 2020) and pre-pandemic era (February 1 to April 30, 2017, 2018, and 2019) were analyzed in this study. Main outcomes were the incidence of time delay, cardiac arrest, and in-hospital death.ResultsThere was 13.5% reduction in the number of patients hospitalized with AMI during the pandemic compared to pre-pandemic era. In patients with STEMI, door to balloon time tended to be longer during the pandemic compared to pre-pandemic era (55.7 ± 12.6 minutes vs. 60.8 ± 13.0 minutes, P = 0.08). There were no significant differences in cardiac arrest (15.6% vs. 10.4%, P = 0.397) and in-hospital mortality (15.6% vs. 10.4%, P = 0.397) between pre-pandemic and the pandemic era. In patients with non-STEMI, symptom to door time was significantly longer (310.0 ± 346.2 minutes vs. 511.5 ± 635.7 minutes, P = 0.038) and the incidence of cardiac arrest (0.9% vs. 3.5%, P = 0.017) and in-hospital mortality (0.3% vs. 2.3%, P = 0.045) was significantly greater during the pandemic compared to pre-pandemic era. Among medications, angiotensin converting enzyme inhibitors/angiotensin type 2 receptor blockers (ACE-I/ARBs) were underused in STEMI (64.6% vs. 45.8%, P = 0.021) and non-STEMI (67.8% vs. 57.0%, P = 0.061) during the pandemic.ConclusionDuring the COVID-19 pandemic, there has been a considerable reduction in hospital admissions for AMI, time delay, and underuse of ACE-I/ARBs for the management of AMI, and this might be closely associated with the excess death in Korea. 相似文献
58.
Comparative toxicity of silicon dioxide,silver and iron oxide nanoparticles after repeated oral administration to rats 下载免费PDF全文
Jun‐Won Yun Seung‐Hyun Kim Ji‐Ran You Woo Ho Kim Ja‐June Jang Seung‐Kee Min Hee Chan Kim Doo Hyun Chung Jayoung Jeong Byeong‐Cheol Kang Jeong‐Hwan Che 《Journal of applied toxicology : JAT》2015,35(6):681-693
Although silicon dioxide (SiO2), silver (Ag) and iron oxide (Fe2O3) nanoparticles are widely used in diverse applications from food to biomedicine, in vivo toxicities of these nanoparticles exposed via the oral route remain highly controversial. To examine the systemic toxicity of these nanoparticles, well‐dispersed nanoparticles were orally administered to Sprague–Dawley rats daily over a 13‐week period. Based on the results of an acute toxicity and a 14‐day repeated toxicity study, 975.9, 1030.5 and 1000 mg kg–1 were selected as the highest dose of the SiO2, Ag and Fe2O3 nanoparticles, respectively, for the 13‐week repeated oral toxicity study. The SiO2 and Fe2O3 nanoparticles did not induce dose‐related changes in a number of parameters associated with the systemic toxicity up to 975.9 and 1000 mg kg–1, respectively, whereas the Ag nanoparticles resulted in increases in serum alkaline phosphatase and calcium as well as lymphocyte infiltration in liver and kidney, raising the possibility of liver and kidney toxicity induced by the Ag nanoparticles. Compared with the SiO2 and Fe2O3 nanoparticles showing no systemic distribution in all tissues tested, the Ag concentration in sampled blood and organs in the Ag nanoparticle‐treated group significantly increased with a positive and/or dose‐related trend, meaning that the systemic toxicity of the Ag nanoparticles, including liver and kidney toxicity, might be explained by extensive systemic distribution of Ag originating from the Ag nanoparticles. Our current results suggest that further study is required to identify that Ag detected outside the gastrointestinal tract were indeed a nanoparticle form or ionized form. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
59.
60.