全文获取类型
收费全文 | 246362篇 |
免费 | 21059篇 |
国内免费 | 14207篇 |
专业分类
耳鼻咽喉 | 2204篇 |
儿科学 | 3050篇 |
妇产科学 | 4902篇 |
基础医学 | 28724篇 |
口腔科学 | 4265篇 |
临床医学 | 31469篇 |
内科学 | 40436篇 |
皮肤病学 | 2840篇 |
神经病学 | 13825篇 |
特种医学 | 8585篇 |
外国民族医学 | 96篇 |
外科学 | 27231篇 |
综合类 | 34475篇 |
现状与发展 | 48篇 |
一般理论 | 45篇 |
预防医学 | 15265篇 |
眼科学 | 6777篇 |
药学 | 24376篇 |
240篇 | |
中国医学 | 11246篇 |
肿瘤学 | 21529篇 |
出版年
2024年 | 2680篇 |
2023年 | 4622篇 |
2022年 | 8988篇 |
2021年 | 11676篇 |
2020年 | 8920篇 |
2019年 | 7652篇 |
2018年 | 8041篇 |
2017年 | 7053篇 |
2016年 | 6763篇 |
2015年 | 10132篇 |
2014年 | 12745篇 |
2013年 | 11910篇 |
2012年 | 17578篇 |
2011年 | 19223篇 |
2010年 | 11726篇 |
2009年 | 9381篇 |
2008年 | 12763篇 |
2007年 | 12808篇 |
2006年 | 12363篇 |
2005年 | 12444篇 |
2004年 | 8605篇 |
2003年 | 7636篇 |
2002年 | 6609篇 |
2001年 | 5987篇 |
2000年 | 6105篇 |
1999年 | 6402篇 |
1998年 | 3650篇 |
1997年 | 3670篇 |
1996年 | 2791篇 |
1995年 | 2581篇 |
1994年 | 2230篇 |
1993年 | 1496篇 |
1992年 | 2289篇 |
1991年 | 1995篇 |
1990年 | 1664篇 |
1989年 | 1454篇 |
1988年 | 1264篇 |
1987年 | 1176篇 |
1986年 | 941篇 |
1985年 | 748篇 |
1984年 | 491篇 |
1983年 | 381篇 |
1982年 | 225篇 |
1981年 | 201篇 |
1980年 | 191篇 |
1979年 | 244篇 |
1978年 | 141篇 |
1977年 | 112篇 |
1976年 | 97篇 |
1974年 | 116篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
962.
Jie Tian Xiao-Long Wang Long-Cheng Wang Fei Chen Yun Tian Li Ma Chao-Yun Pan Yan-Ping Wang 《Pharmaceutical biology》2022,60(1):1331
ContextQiangli Wuhu (QLWH) mixture is a concoction approved and registered by Ningxia Medical Products Administration. It has therapeutic effects on various types of pneumonia.ObjectiveTo clarify the mechanisms of QLWH in treating pneumonia.Materials and methodsThe potential targets of QLWH in the treatment of pneumonia were predicted by network pharmacology. Male, Institute of Cancer Research (ICR) mice were randomly divided into five groups of 12 mice, control, vehicle, QLWH (10 and 20 mg/kg) and dexamethasone (DXM), and orally treated twice daily with normal saline, QLWH or DXM. The pneumonia model was established by tracheal instillation of lipopolysaccharide (LPS). After treatment five days, ELISA, H&E staining and Western blot were used to investigate protective effects of QLWH.ResultsNine hundred and ninety-four active ingredients were found through network pharmacology, corresponding to 135 targets for the treatment of pneumonia; compared to the vehicle group, QLWH (10 and 20 mg/kg) significantly decreased the levels of TNF-α (14.3% and 28.8%), IL-1β (23.9% and 42.8%) and IL-6 (13.2% and 16.1%), increased the levels of IL-10 (134.3% and 172.9%); in terms of mechanism, QLWH down-regulated TLR4/NF-κB/NLRP3 axis related proteins in lung tissue of pneumonia model mice (p < 0.05).Discussion and conclusionsThis study combined network pharmacology and animal experiments, providing effective evidence for the clinical promotion of QLWH. Meanwhile, it is of significance for further development. 相似文献
963.
964.
Yuehan Chen Xu Zhang Xiansheng Zeng Tingting Xu Wei Xiao Xuejiao Yang Wenzhi Zhan Chen Zhan Kefang Lai 《Journal of thoracic disease》2022,14(6):2079
BackgroundCough is one of the most common symptoms of coronavirus disease 2019 (COVID-19). However, the prevalence of persistent cough in recovered patients with COVID-19 during a longer follow-up remained unknown. This study aims to investigate the prevalence, and risk factors for postinfectious cough in COVID-19 patients after discharge.MethodsWe conducted a follow-up study for 129 discharged patients with laboratory-confirmed COVID-19 in two large hospitals located in Hubei Province, China from January 2020 to December 2020. Baseline demographics, comorbidities and smoking history were extracted from the medical record. Current symptoms and severity were recorded by a uniform questionnaire. Spirometry, diffuse function and chest computed tomography (CT) were performed on part of patients who were able to return to the outpatient department at follow-up.ResultsThe median (interquartile range) follow-up time was 8.1 (7.9–8.5) months after discharge. The mean (standard deviation) age was 51.5 (14.9) years and 57 (44.2%) were male. A total of 27 (20.9%) patients had postinfectious cough (>3 weeks), 6 patients (4.7%) had persistent cough by the end of follow-up, including 3 patients with previous chronic respiratory diseases or current smoking. Other symptoms included dyspnea (6, 4.7%), sputum (4, 3.1%), fatigue (4, 3.1%), and anorexia (4, 3.1%) by the end of follow-up. Thirty-six of 41 (87.8%) patients showed impaired lung function or diffuse function, and 39 of 50 (78.0%) patients showed abnormal CT imaging. Patients with postinfectious cough demonstrated more severe and more frequent cough during hospitalization (P<0.001), and more chronic respiratory diseases (P=0.01). In multivariate logistic regression analysis, digestive symptoms during hospitalization [odds ratio (OR) 2.95, 95% confidence interval (CI): 1.10–7.92] and current smoking (OR 6.95, 95% CI: 1.46–33.14) were significantly associated with postinfectious cough of COVID-19.ConclusionsA small part of patients developed postinfectious cough after recovery from COVID-19, few patients developed chronic cough in spite of a higher proportion of impaired lung function and abnormal lung CT image. Current smoking and digestive symptoms during hospitalization were risk factors for postinfectious cough in COVID-19. 相似文献
965.
Yang Liu Hongyan Wang Sen Yang Yuanyuan Yang Yufeng Wu Zhen He Shuxiang Ma Yuqing Mo Haiyang Chen Qiming Wang Hong Ge 《Journal of thoracic disease》2022,14(6):2254
BackgroundEpidermal growth factor receptor tyrosine kinases inhibitors (EGFR-TKIs) are currently recognized as the standard treatment for advanced non-small cell lung cancer (NSCLC) patients with EGFR mutations. Clinically found patients with different EGFR mutational status have different prognosis.MethodsA retrospective cohort study was performed to explore the relationship between EGFR mutations and abundance with patient survival by using patient data from the Affiliated Cancer Hospital of Zhengzhou University between January 2013 and November 2016. All patients involved in the present study had sensitive EGFR mutations [either exon 19 deletion (DEL) or exon 21 L858R] and treated by EGFR-TKIs. They were followed up every three months until lost or dead. Mutation abundance was calculated as the copies of EGFR mutation divided by copies of EGFR locus, and the cut-off values for 19DEL and L858R were 4.9% and 9.5%, respectively.ResultsTotal of 236 patients were included, comprising 116 (49.2%) patients with 19DEL mutation and 120 (50.8%) patients with L858R mutation. The median follow-up duration was 23.2 months (95% CI: 14.9–26.7 months). Overall survival (OS) was significantly longer in patients with 19DEL mutation (20.9 months, 95% CI: 17.7–24.1 months versus 17.0 months, 95% CI: 14.4–19.6 months in patients with L858R; P=0.008) and in patients with high mutation abundance (20.9 months, 95% CI: 18.3–23.5 months versus 13.0 months, 95% CI: 10.3–15.7 months in patients with low mutation abundance; P<0.001). Multivariate Cox regression including age, performance status and tumor stage revealed that longer OS was independently associated with 19DEL mutation (HR: 0.48, 95% CI: 0.39–0.67, P=0.033) and high mutation abundance (HR: 0.62, 95% CI: 0.50–0.79, P=0.027).ConclusionsEGFR mutation types and abundance was associated with the patients’ survival which might be used to predict the efficacy of targeted therapy by EGFR-TKIs. 相似文献
966.
967.
Yang Liu Xin Zhang Shuo Chen Jiazhong Wang Shuo Yu Yiming Li Meng Xu Harouna Aboubacar Junhui Li Tao Shan Jixin Wang Gang Cao 《Clinical and molecular hepatology》2022,28(3):522
Background/AimsBinge drinking leads to many disorders, including alcoholic hepatosteatosis, which is characterized by intrahepatic neutrophil infiltration and increases the risk of hepatocellular carcinoma (HCC). Molecular mechanisms may involve the migration of bacterial metabolites from the gut to the liver and the activation of neutrophil extracellular traps (NETs).MethodsSerum samples from both binge drinking and alcohol-avoiding patients were analyzed. Mouse models of chronic plus binge alcohol-induced hepatosteatosis and HCC models were used.ResultsA marker of NETs formation, lipopolysaccharide (LPS), was significantly higher in alcoholic hepatosteatosis and HCC patients and mice than in controls. Intrahepatic inflammation markers and HCC-related cytokines were decreased in mice with reduced NET formation due to neutrophil elastase (NE) deletion, and liver-related symptoms of alcohol were also alleviated in NE knockout mice. Removal of intestinal bacteria with antibiotics led to decreases in markers of NETs formation and inflammatory cytokines upon chronic alcohol consumption, and development of alcoholic hepatosteatosis and HCC was also attenuated. These functions were restored upon supplementation with the bacterial product LPS. When mice lacking toll-like receptor 4 (TLR4) received chronic alcohol feeding, intrahepatic markers of NETs formation decreased, and hepatosteatosis and HCC were alleviated.ConclusionsFormation of NETs following LPS stimulation of TLR4 upon chronic alcohol use leads to increased alcoholic steatosis and subsequent HCC. 相似文献
968.
Mengdi Zhang Jianhua Liu Chen Li Jianwei Gao Chuanhui Xu Xiaoyu Wu Tiesheng Xu Chenbin Cui Hongkui Wei Jian Peng Rong Zheng 《Nutrients》2022,14(13)
Obesity may cause metabolic syndrome and has become a global public health problem, and dietary fibers (DF) could alleviate obesity and metabolic syndrome by regulating intestinal microbiota. We developed a functional fiber (FF) with a synthetic mixture of polysaccharides, high viscosity, water-binding capacity, swelling capacity, and fermentability. This study aimed to investigate the effect of FF on obesity and to determine its prevention of obesity by modulating the gut microbiota. Physiological, histological, and biochemical parameters, and gut microbiota composition were investigated in the following six groups: control group (Con), high-fat diet group (HFD), low-fat diet group (LFD, conversion of HFD to LFD), high-fat +8% FF group (8% FF), high-fat +12% FF group (12% FF), and high-fat +12% FF + antibiotic group (12% FF + AB). The results demonstrated that 12% FF could promote a reduction in body weight and epididymal adipocyte area, augment insulin sensitivity, and stimulate heat production from brown adipose tissue (BAT) (p < 0.05). Compared with the HFD, 12% FF could also significantly improve the intestinal morphological integrity, attenuate systemic inflammation, promote intestinal microbiota homeostasis, and stabilize the production of short-chain fatty acids (SCFAs) (p < 0.05). Consistent with the results of 12% FF, the LFD could significantly reduce the body weight and epididymal adipocyte area relative to the HFD (p < 0.05), but the LFD and HFD showed no significant difference (p > 0.05) in the level of inflammation and SCFAs. Meanwhile, 12% FF supplementation showed an increase (p < 0.05) in the abundance of the Bifidobacterium, Lactococcus, and Coprococcus genus in the intestine, which had a negative correlation with obesity and insulin resistance. Additionally, the treatment with antibiotics (12% FF + AB) could inhibit the effect of FF in the HFD. The Kyoto Encyclopedia of Genes and Genomes (KEGG) function prediction revealed that 12% FF could significantly inhibit the cyanogenic amino acid metabolic pathway and decrease the serum succinate concentration relative to the HFD group. The overall results indicate that 12% FF has the potential to reduce obesity through the beneficial regulation of the gut microbiota and metabolites. 相似文献
969.
Shuting Qiu Jiajia Chen Yan Bai Jincan He Hua Cao Qishi Che Jiao Guo Zhengquan Su 《Nutrients》2022,14(13)
The treatment of nonalcoholic fatty liver disease (NAFLD) remains very challenging. This study investigated the therapeutic effect of galactose oligosaccharide (GOS), an important prebiotic, on NAFLD through in vivo and in vitro experiments and preliminarily explored the mechanism by which GOS improves liver lipid metabolism and inflammation through liver and intestinal microbiological analysis. The results of mouse liver lipidomics showed that GOS could promote body thermogenesis in mice with high-fat and high-sugar diet (HFHSD)-induced NAFLD, regulate lipolysis in liver fat cells, and accelerate glycine and cholesterol metabolism. GOS dose-dependently reduced the contents of total cholesterol (TC) and triglyceride (TG) in cells and reduced the accumulation of lipid droplets in cells. GOS also reduced the Firmicutes/Bacteroidetes ratio and altered the composition of the intestinal microbiota in mice fed a HFHSD. GOS can improve liver lipid metabolism and intestinal structure of NAFLD. These results provide a theoretical and experimental basis supporting the use of GOS as a health food with anti-NAFLD functions. 相似文献
970.
Zhijun Yu Zhuo Chen Dongdong Qu Shoujiang Qu Hao Wang Fu Zhao Chaoqun Zhang Aihan Feng Daolun Chen 《Materials》2022,15(13)
3D printing (or more formally called additive manufacturing) has the potential to revolutionize the way objects are manufactured, ranging from critical applications such as aerospace components to medical devices, making the materials stronger, lighter and more durable than those manufactured via conventional methods. While the mechanical properties of Ti-6Al-4V parts manufactured with two major 3D printing techniques: selective laser melting (SLM) and electron beam melting (EBM), have been reported, it is unknown if the corrosion resistance of the 3D-printed parts is comparable to that of the alloy made with isothermal forging (ISF). The aim of this study was to identify the corrosion resistance and mechanisms of Ti-6Al-4V alloy manufactured by SLM, EBM and ISF via electrochemical corrosion tests in 3.5% NaCl solution, focusing on the effect of microstructures. It was observed that the equiaxed α + β microstructure in the ISF-manufactured Ti-6Al-4V alloy had a superior corrosion resistance to the acicular martensitic α′ + β and lamellar α + β microstructures of the 3D-printed samples via SLM and EBM, respectively. This was mainly due to the fact that (1) a higher amount of β phase was present in the ISF-manufactured sample, and (2) the fraction of phase interfaces was lower in the equiaxed α + β microstructure than in the acicular α′ + β and lamellar α + β microstructures, leading to fewer microgalvanic cells. The lower corrosion resistance of SLM-manufactured sample was also related to the higher strain energy and lower electrochemical potential induced by the presence of martensitic twins, resulting in faster anodic dissolution and higher corrosion rate. 相似文献