全文获取类型
收费全文 | 108286篇 |
免费 | 11318篇 |
国内免费 | 3446篇 |
专业分类
耳鼻咽喉 | 900篇 |
儿科学 | 1287篇 |
妇产科学 | 1019篇 |
基础医学 | 12247篇 |
口腔科学 | 4378篇 |
临床医学 | 10939篇 |
内科学 | 10370篇 |
皮肤病学 | 1321篇 |
神经病学 | 7123篇 |
特种医学 | 3545篇 |
外国民族医学 | 11篇 |
外科学 | 7978篇 |
综合类 | 16359篇 |
现状与发展 | 10篇 |
一般理论 | 3篇 |
预防医学 | 16585篇 |
眼科学 | 1263篇 |
药学 | 15321篇 |
115篇 | |
中国医学 | 7524篇 |
肿瘤学 | 4752篇 |
出版年
2024年 | 172篇 |
2023年 | 1882篇 |
2022年 | 2839篇 |
2021年 | 4872篇 |
2020年 | 5005篇 |
2019年 | 4396篇 |
2018年 | 4008篇 |
2017年 | 4333篇 |
2016年 | 4382篇 |
2015年 | 4314篇 |
2014年 | 7650篇 |
2013年 | 8345篇 |
2012年 | 7547篇 |
2011年 | 7890篇 |
2010年 | 5902篇 |
2009年 | 5451篇 |
2008年 | 5175篇 |
2007年 | 5166篇 |
2006年 | 4453篇 |
2005年 | 3905篇 |
2004年 | 3201篇 |
2003年 | 2928篇 |
2002年 | 2301篇 |
2001年 | 2151篇 |
2000年 | 1684篇 |
1999年 | 1415篇 |
1998年 | 1249篇 |
1997年 | 1134篇 |
1996年 | 963篇 |
1995年 | 1003篇 |
1994年 | 962篇 |
1993年 | 748篇 |
1992年 | 714篇 |
1991年 | 619篇 |
1990年 | 518篇 |
1989年 | 541篇 |
1988年 | 468篇 |
1987年 | 396篇 |
1986年 | 324篇 |
1985年 | 403篇 |
1984年 | 338篇 |
1983年 | 198篇 |
1982年 | 229篇 |
1981年 | 186篇 |
1980年 | 169篇 |
1979年 | 138篇 |
1978年 | 97篇 |
1977年 | 67篇 |
1976年 | 81篇 |
1974年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
近年来凭借大数据及深度学习使得以纹理分析(Texture Analysis)为代表的影像组学迅猛发展。随着纹理分析方法及影像新技术的不断研发应用,近年来纹理分析被越来越多的应用于临床研究,为疾病、尤其是肿瘤的诊断、分级与疗效预测评估提供有价值的医学影像依据。本文总结了纹理分析的常用方法、流程,并对软组织肿瘤的研究现况进行调查,作一综述。 相似文献
33.
《Clinical genitourinary cancer》2022,20(6):594-602
The management of patients with metastatic hormone-sensitive prostate cancer (mHSPC) has been significantly modified by the availability of innovative but expensive treatments, increasing the economic burden of prostate cancer. Here, we aimed to systematically identify and review published economic evaluations (EEs) related to the treatment of mHSPC and assess their quality. A systematic search was performed of the PubMed and Cochrane databases. Three reviewers independently selected EEs by defined inclusion and exclusion criteria. They extracted all data from each EE (general information, study population, data about the EE, interventions and comparators, and outcomes). They also assessed the quality of the selected EEs according to Drummond's checklist. Fourteen EEs published between 2016 and 2021 were eligible for the systematic review. The EEs found ADT + docetaxel to be the most cost-effective of all available treatments as a first-line strategy for mHSPC (abiraterone acetate plus prednisone, enzalutamide, and apalutamide). Five EEs showed that a simple price reduction of abiraterone acetate of 50% to 75% could change the results to render this treatment also cost-effective relative to that with docetaxel. Twelve EEs were of high quality, with a Drummond score ≥ 7. Analysis of the 14 EEs identified by our systematic review, amongst which 78.6% met high quality standards, showed that ADT + docetaxel tends to be the most cost-effective alternative for mHSPC. These results were assessed by sensitivity analysis. The data provided by this systematic review help to provide a better understanding of these treatments and the better use of healthcare resources. 相似文献
34.
35.
Ochratoxin A (OTA) is a mycotoxin that mainly causes nephrotoxicity. The single nephrotoxicity of OTA exposure on glomeruli or renal tubule had been well documented, however, the comparison toxicity between it is still unclear. Here, C57BL/6 mice and two types of nephrocyte were treated with concentration-gradient OTA to explore its differentiation nephrotoxicity. Results showed that OTA induced nephrotoxicity in vivo and in vitro, manifested as the deteriorative kidney function in mice and the cut-down cell viability in nephrocyte. Besides, results of murine kidney pathological section and IC50 of two types nephrocyte indicated that OTA-induced toxicity in renal tubule was higher than its in glomeruli. In addition, OTA exposure induced autophagy signaling differentiation expression. It revealed that autophagy was implicated in OTA-induced differential nephrotoxicity in glomeruli and renal tubule. Altogether, we proved that OTA induces a differentiation nephrotoxicity in glomeruli and renal tubule, and it is related to autophagy differential regulation. 相似文献
36.
《Journal of the American Medical Directors Association》2022,23(7):1185-1190
ObjectivesWith the increase in older adults receiving long-term care in facilities, the level of social engagement within nursing homes is a growing concern for improving the quality of life of residents. This study seeks to assess the level of social engagement and identify the factors associated with high and low engagement among older adults in Korean nursing homes.DesignCross-sectional study.Setting and ParticipantsData were obtained from a nationally representative sample of 1453 older residents in 92 long-term care facilities across Korea.MethodsMultilevel-multivariate analyses were carried out to identify individual- and institution-level risk factors of social engagement, as measured by the Revised Index of Social Engagement (RISE).ResultsThree-fourths of older residents had a low level of social engagement, whereas only about one tenth showed a high level of social engagement. Being male, having severe functional impairments, having depression, and having no supportive family relationships were risk factors for low social engagement. Conversely, a high level of social engagement was significantly associated with being female, having no impairments, and a longer length of stay. Meeting staffing requirements for personal care assistants, an institution-level factor, was negatively associated with low social engagement and positively associated with high social engagement.Conclusions and ImplicationsLow social engagement is very common in Korean nursing homes and is concentrated among those with poor functional and social outcomes. Future efforts to improve long-term care will need to address the various factors associated with social engagement in designing social care for nursing home residents. 相似文献
37.
《Journal of Cardiovascular Computed Tomography》2022,16(5):397-403
BackgroundPretest probability (PTP) calculators utilize epidemiological-level findings to provide patient-level risk assessment of obstructive coronary artery disease (CAD). However, their limited accuracies question whether dissimilarities in risk factors necessarily result in differences in CAD. Using patient similarity network (PSN) analyses, we wished to assess the accuracy of risk factors and imaging markers to identify ≥50% luminal narrowing on coronary CT angiography (CCTA) in stable chest-pain patients.MethodsWe created four PSNs representing: patient characteristics, risk factors, non-coronary imaging markers and calcium score. We used spectral clustering to group individuals with similar risk profiles. We compared PSNs to a contemporary PTP score incorporating calcium score and risk factors to identify ≥50% luminal narrowing on CCTA in the CT-arm of the PROMISE trial. We also conducted subanalyses in different age and sex groups.ResultsIn 3556 individuals, the calcium score PSN significantly outperformed patient characteristic, risk factor, and non-coronary imaging marker PSNs (AUC: 0.81 vs. 0.57, 0.55, 0.54; respectively, p ?< ?0.001 for all). The calcium score PSN significantly outperformed the contemporary PTP score (AUC: 0.81 vs. 0.78, p ?< ?0.001), and using 0, 1–100 and ?> ?100 cut-offs provided comparable results (AUC: 0.81 vs. 0.81, p ?= ?0.06). Similar results were found in all subanalyses.ConclusionCalcium score on its own provides better individualized obstructive CAD prediction than contemporary PTP scores incorporating calcium score and risk factors. Risk factors may not be able to improve the diagnostic accuracy of calcium score to predict ≥50% luminal narrowing on CCTA. 相似文献
38.
目的 应用可视化方法分析代谢组学在中医药领域的现状及趋势。方法 检索中国知网数据库(CNKI)和Web of Science 核心合集数据库2021年3月15日之前收录的中医药领域代谢组学研究的相关文献,应用CiteSpace软件对纳入的文献进行关键词、作者、研究机构等内容进行可视化分析。结果 共纳入中文文献247篇,英文文献350篇。文献数量在波动中迅速上升。中、英文文献作者合作网络显示,张爱华是中医药领域代谢组学研究发文量最多的作者,并形成了核心研究团队。发文机构显示,中国医学科学院是该领域的重要研究机构,机构间合作紧密。中、英文文献关键词分析显示,研究内容主要集中在核磁共振、代谢标记物、冠心病、质谱技术、代谢通路等相关领域。结论 中医药领域代谢组学研究的热点主要为中医药治疗代谢性疾病的机制研究。研究趋势为卵泡代谢组学研究及中药有效成分的研究。 相似文献
39.
Georg Prokop Benedikt Wiestler Daniel Hieber Fynn Withake Karoline Mayer Jens Gempt Claire Delbridge Friederike Schmidt-Graf Nicole Pfarr Bruno Märkl Jürgen Schlegel Friederike Liesche-Starnecker 《International journal of cancer. Journal international du cancer》2023,153(9):1658-1670
Intratumor heterogeneity is a main cause of the dismal prognosis of glioblastoma (GBM). Yet, there remains a lack of a uniform assessment of the degree of heterogeneity. With a multiscale approach, we addressed the hypothesis that intratumor heterogeneity exists on different levels comprising traditional regional analyses, but also innovative methods including computer-assisted analysis of tumor morphology combined with epigenomic data. With this aim, 157 biopsies of 37 patients with therapy-naive IDH-wildtype GBM were analyzed regarding the intratumor variance of protein expression of glial marker GFAP, microglia marker Iba1 and proliferation marker Mib1. Hematoxylin and eosin stained slides were evaluated for tumor vascularization. For the estimation of pixel intensity and nuclear profiling, automated analysis was used. Additionally, DNA methylation profiling was conducted separately for the single biopsies. Scoring systems were established to integrate several parameters into one score for the four examined modalities of heterogeneity (regional, cellular, pixel-level and epigenomic). As a result, we could show that heterogeneity was detected in all four modalities. Furthermore, for the regional, cellular and epigenomic level, we confirmed the results of earlier studies stating that a higher degree of heterogeneity is associated with poorer overall survival. To integrate all modalities into one score, we designed a predictor of longer survival, which showed a highly significant separation regarding the OS. In conclusion, multiscale intratumor heterogeneity exists in glioblastoma and its degree has an impact on overall survival. In future studies, the implementation of a broadly feasible heterogeneity index should be considered. 相似文献