全文获取类型
收费全文 | 340975篇 |
免费 | 29418篇 |
国内免费 | 20690篇 |
专业分类
耳鼻咽喉 | 2988篇 |
儿科学 | 4256篇 |
妇产科学 | 6626篇 |
基础医学 | 40183篇 |
口腔科学 | 5905篇 |
临床医学 | 43988篇 |
内科学 | 54848篇 |
皮肤病学 | 3948篇 |
神经病学 | 19009篇 |
特种医学 | 11970篇 |
外国民族医学 | 155篇 |
外科学 | 36640篇 |
综合类 | 49868篇 |
现状与发展 | 65篇 |
一般理论 | 50篇 |
预防医学 | 21157篇 |
眼科学 | 9626篇 |
药学 | 34688篇 |
256篇 | |
中国医学 | 16057篇 |
肿瘤学 | 28800篇 |
出版年
2024年 | 762篇 |
2023年 | 4266篇 |
2022年 | 10300篇 |
2021年 | 15633篇 |
2020年 | 11501篇 |
2019年 | 10585篇 |
2018年 | 11103篇 |
2017年 | 9848篇 |
2016年 | 9345篇 |
2015年 | 14040篇 |
2014年 | 17813篇 |
2013年 | 16720篇 |
2012年 | 24456篇 |
2011年 | 26938篇 |
2010年 | 16500篇 |
2009年 | 13239篇 |
2008年 | 18000篇 |
2007年 | 18118篇 |
2006年 | 17796篇 |
2005年 | 17852篇 |
2004年 | 12277篇 |
2003年 | 11175篇 |
2002年 | 9585篇 |
2001年 | 8784篇 |
2000年 | 8968篇 |
1999年 | 9374篇 |
1998年 | 5563篇 |
1997年 | 5578篇 |
1996年 | 4201篇 |
1995年 | 3879篇 |
1994年 | 3348篇 |
1993年 | 2217篇 |
1992年 | 3390篇 |
1991年 | 2935篇 |
1990年 | 2476篇 |
1989年 | 2183篇 |
1988年 | 1913篇 |
1987年 | 1746篇 |
1986年 | 1377篇 |
1985年 | 1160篇 |
1984年 | 719篇 |
1983年 | 546篇 |
1982年 | 333篇 |
1981年 | 309篇 |
1980年 | 260篇 |
1979年 | 359篇 |
1978年 | 198篇 |
1977年 | 152篇 |
1976年 | 149篇 |
1974年 | 181篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Hepatitis E virus (HEV) is the most common cause of acute liver failure (LF) and one of the most common factors causing acute injury in acute-on-chronic LF (ACLF). When HEV-related LF occurs, a series of changes take place in both the intrahepatic environment and extrahepatic microenvironment. The changed types and distribution of immune cells (infiltrating macrophages and increased lymphocytes) in liver tissue, as well the increased proinflammatory cytokines and chemokines in the blood, indicate that the occurrence and progression of HEV-related LF are closely related to immune imbalance. The clinical features and immune reaction in the body during HEV-related acute LF (ALF) and ACLF are complicated. This review highlights recent progress in elucidating the clinical manifestations of HEV-associated ALF and ACLF and discusses the corresponding systemic immune changes and possible regulatory mechanisms. 相似文献
102.
ObjectiveTo investigate the feasibility of transnasal heated humidified high flow nasal cannula oxygen therapy (HFNC) in the treatment of acute exacerbation of chronic obstructive pulmonary disease (AECOPD) with respiratory failure in elderly patients. MethodsA total of 176 elderly patients with AECOPD complicated with respiratory failure who were hospitalized at Peking University Shougang Hospital from December 2016 to January 2022 were enrolled, including 82 patients in an HFNC group and 94 patients in an NPPV group. After treatment, pulse oxygen saturation (SPO2), arterial partial pressure of carbon dioxide (PaCO2), oxygenation index (OI), respiratory rate (RR), heart rate (HR), mean arterial pressure (MAP), comfort score, discharge rate, rate of endotracheal intubation, rate of transfer to intensive care unit (ICU), and mortality were compared between the two groups. The independent sample t-test was used for comparison between the two groups. Statistical data are expressed in percentage or number of cases and the χ2 test was used for their comparisons. ResultsThe SPO2 values at 30 min, 1 h, and 6 h were significantly higher in the HFNC group than in the NPPV group (t=-2.049,-2.618, and -3.314, P=0.043, 0.010, and 0.001, respectively). SPO2 before discharge was significantly lower than that of the NPPV group (t=2.162, P=0.033), but OI at each time point and before discharge had no statistical significance (P>0.05). MAP at 6 h was significantly higher in the HFNC group than in the NPPV group (t=-2.209, P=0.029), but within the normal range. HRs at 2 h and 3 h in the HFNC group were significantly higher than those of the NPPV group (t=-2.199 and -2.336, P=0.030 and 0.021, respectively). There were no significant differences in RR, HR, or MAP between the two groups at other time points and before discharge (P>0.05). There was no significant difference in PaCO2 between the two groups (P>0.05). Comfort score in the HFNC group was significantly higher than that of the NPPV group (t=-46.807, P<0.001). There were no significant differences in discharge rate, ICU transfer rate, endotracheal intubation rate, and mortality between the two groups (P>0.05). ConclusionHFNC is as effective as NPPV in treating elderly patients with AECOPD complicated with type Ⅰ or mild type Ⅱ respiratory failure, and HFNC is more comfortable than NPPV. 相似文献
103.
知识点模块网格化模型在肾内科实习生带教中的应用 《医学教育管理》2019,5(1):34-37
目的 运用知识点模块网格化构建带教模型,观察其在肾内科实习生中的应用效果。方法 根据《内科学》(第八版)肾内科教学大纲要求,结合肾内科病房常见病、多发病的临床特点,精心挑选相关知识点,以理论为支撑点,以服务于实习带教工作为靶目标,各个知识点之间有临床的关联性,最终形成网格化的诊治分
析模型。将血尿、蛋白尿、高血压、水肿、肾小球滤过率为切入点,设定肾病综合征、系统性红斑狼疮、糖尿病肾病和急、慢性肾功能衰竭为临床知识必须掌握点,从病史、症状、体征和实验室检查几方面来培养实习生的诊疗思维,并通过知识点来关联疾病的诊治,从而帮助他们在有限的肾内科实习期间尽可能掌握肾内科临床知识。结果 本研究开展一年以来,对于来肾内科轮转的51 名实习生进行了模块网格化模型训练,实习生普遍反映该模型有很好的学习效果,让他们了解了肾内科临床重点,并能和理论学习的知识点有机融合在一起,开阔了实习生的诊疗视野,也便于对其他科知识点的学习。结论 基于知识点模块网格化,构建模型在肾内科实习生中有很好的带教作用,学生接受肾内科知识点的记忆增强,并能进一步推广到内科其他内容的实习带教中。 相似文献
104.
105.
Michael W. Manning Yi-Ju Li Dean Linder John C. Haney Yi-Hung Wu Mihai V. Podgoreanu Madhav Swaminathan Jacob N. Schroder Carmelo A. Milano Ian J. Welsby Mark Stafford-Smith Kamrouz Ghadimi 《Journal of cardiothoracic and vascular anesthesia》2021,35(5):1310-1318
- Download : Download high-res image (215KB)
- Download : Download full-size image
106.
Discoid lupus erythematosus (DLE) is the most common skin manifestation of lupus; however, the molecular mechanisms underlying DLE remain unknown. Therefore, we aimed to identify key differentially expressed genes (DEGs) in discoid lupus skin and investigate their potential pathways.To identify candidate genes involved in the occurrence and development of the disease, we downloaded the microarray datasets and GSE52471 from the Gene Expression Database (GEO). DEGs between discoid lupus skin and normal controls were selected using the GEO2R tool and Venn diagram software ( GSE72535http://bioinformatics.psb.ugent.be/webtools/Venn/). The Database for Annotation, Visualization, and Integrated Discovery (DAVID), Enrichr, and Cytoscape ClueGo were used to analyze the Kyoto Encyclopedia of Gene and Genome pathways and gene ontology. Protein-protein interactions (PPIs) of these DEGs were further assessed using the Search Tool for the Retrieval Interacting Genes version 10.0.Seventy three DEGs were co-expressed in both datasets. DEGs were predominantly upregulated in receptor signaling pathways of the immune response. In the PPI network, 69 upregulated genes were selected. Furthermore, 4 genes (CXCL10, ISG15, IFIH1, and IRF7) were found to be significantly upregulated in the RIG-I-like receptor signaling pathway, from analysis of Enrichr and Cytoscape ClueGo.The results of this study may provide new insights into the potential molecular mechanisms of DLE. However, further experimentation is required to confirm these findings. 相似文献
107.
Xiaojie Wu Leyan Zhang Jiadi Zhou Luying Liu Qiang Fu Aili Fu Xiaoying Feng Rui Xin Hongrui Liu Yong Gao Jiangnan Xue 《Current problems in cancer》2019,43(1):18-26
Aim
Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an immune inhibitory receptor which is expressed within most types of hematopoietic cells and negatively regulates immune responses. Recently, we found LAIR-1 expression to be present within tumors of nonhematopoietic lineages. However, the roles of LAIR-1 in hepatocellular carcinoma (HCC) have yet to be examined. The purpose of this study was to investigate the expression of LAIR-1 in HCC tissue and assess its clinical significance at this site.Materials and methods
Expression levels of LAIR-1 within HCC samples collected from 90 patients and compared with that of slides of normal liver tissue collected from 9 non-HCC patients were measured by immunohistochemistry using tissue microarrays. A semiquantitative score was assigned, as was based on staining intensity and percent of positive cells and a Spearman Rank correlation test was used to assess any potential significant correlations between LAIR-1 expression and clinicopathological factors. Overall survival analysis was performed using the Kaplan-Meier and Log Rank statistical test.Results
LAIR-1 expression was detected in cancer tissue and adjacent tumor tissue, but not in normal liver tissue. The percent of LAIR-1-positive expression in cancer tissue of HCC samples was 97.78% (88/90) while that in adjacent tumor tissue was 96.67% (87/90). Significantly greater expression levels of LAIR-1 were obtained from cancer tissue (Mean?±?SD?=?5.722?±?2.145) than that in adjacent tumor tissue (4.141?±?1.486). In addition, LAIR-1 expression was found to be significantly correlated with pathological grade of HCC, T stage, and age. Expression levels of LAIR-1 were related with worse overall survival rates of HCC patients, especially in HCC patients with hepatic cirrhosis.Conclusion
Results of this study show that LAIR-1 is expressed in HCC tissues and that high levels of LAIR-1 expression are associated with the poor cancer differentiation. In addition, overexpression of LAIR-1 was significantly associated with worse overall survival in the patients with HCC. These data suggest that LAIR-1 may be an independent predictor for clinical outcomes in patients with HCC. 相似文献108.
109.
110.
Jin Wu Hao Wang Qing Li Qian-Ying Guo Si-Qi Tao Yu-Xian Shen Zheng-Sheng Wu 《Pathology, research and practice》2019,215(9):152523
Mammary carcinoma (MC) is one of most common malignancy in women, and ring finger protein 2 (RNF2) possesses various roles in vast human tumors. In MC tissues as well as in cell lines RNF2 exhibited high expression, had significant association with tumor size, lymph node status, TNM stage, patients’ poor survival, and promoted cell proliferation, colony formation, cell migration and invasion of MC cell lines which was mediated by downregulation of E-cadherin protein. These data reveal that RNF2 protein plays a vital role in the development of MC and may be a potential therapy target of MC. 相似文献