全文获取类型
收费全文 | 543088篇 |
免费 | 43674篇 |
国内免费 | 11261篇 |
专业分类
耳鼻咽喉 | 6962篇 |
儿科学 | 14220篇 |
妇产科学 | 9521篇 |
基础医学 | 44792篇 |
口腔科学 | 14382篇 |
临床医学 | 59711篇 |
内科学 | 58567篇 |
皮肤病学 | 6607篇 |
神经病学 | 31948篇 |
特种医学 | 12951篇 |
外国民族医学 | 41篇 |
外科学 | 54471篇 |
综合类 | 82980篇 |
现状与发展 | 25篇 |
一般理论 | 77篇 |
预防医学 | 64589篇 |
眼科学 | 7102篇 |
药学 | 50189篇 |
702篇 | |
中国医学 | 56450篇 |
肿瘤学 | 21736篇 |
出版年
2023年 | 9250篇 |
2022年 | 13683篇 |
2021年 | 22034篇 |
2020年 | 22651篇 |
2019年 | 26504篇 |
2018年 | 23882篇 |
2017年 | 21156篇 |
2016年 | 18700篇 |
2015年 | 17522篇 |
2014年 | 35057篇 |
2013年 | 37361篇 |
2012年 | 31675篇 |
2011年 | 34062篇 |
2010年 | 27521篇 |
2009年 | 24563篇 |
2008年 | 23691篇 |
2007年 | 23994篇 |
2006年 | 20895篇 |
2005年 | 17925篇 |
2004年 | 14727篇 |
2003年 | 12975篇 |
2002年 | 10135篇 |
2001年 | 8887篇 |
2000年 | 7556篇 |
1999年 | 6261篇 |
1998年 | 4891篇 |
1997年 | 4531篇 |
1996年 | 3871篇 |
1995年 | 4026篇 |
1994年 | 3777篇 |
1993年 | 3131篇 |
1992年 | 3032篇 |
1991年 | 2641篇 |
1990年 | 2369篇 |
1989年 | 2122篇 |
1988年 | 2000篇 |
1987年 | 1743篇 |
1986年 | 1649篇 |
1985年 | 4895篇 |
1984年 | 5913篇 |
1983年 | 4166篇 |
1982年 | 4848篇 |
1981年 | 4246篇 |
1980年 | 3770篇 |
1979年 | 3425篇 |
1978年 | 2938篇 |
1977年 | 2215篇 |
1976年 | 2522篇 |
1975年 | 1855篇 |
1974年 | 1626篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
72.
目的 对中医药治疗特发性肺纤维化(idiopathic pulmonary fibrosis, IPF)的系统评价(SRs)进行再评价。方法 检索知网、中国生物医学数据库、维普、万方、The Cochrane Library、Web of Science、PubMed和EMbase数据库,纳入中医药治疗IPF的SRs,截止2021年5月。使用AMSTAR 2量表进行方法学质量评价,GRADE系统工具进行结局指标证据质量分级。结果 共纳入28篇文献,试验组除辨证论治外,治疗方法集中在活血化瘀、补肺益气等方面,基本符合治疗法则。结果显示中医药治疗IPF可以提高有效率、增加肺功能、提高PaO2、增加6WMD、缓解临床症状、提高患者的生活质量等。AMSTAR 2量表评价,所纳入SRs均有多项关键条目不达标,整体方法学质量等级不高。采用GRADE工具进行质量分级,一共234个结局指标,无高等证据质量,整体证据等级不高。结论 中医药对比西医治疗IPF有效且不良反应不明显,但RCT研究和系统评价研究方法质量尚有缺陷,完全按照西医评价指标可能会低估真实结果,未来需要更规范的研究及适合中医的评价指标,对中医药研究的安全性方面关注还有待提高。 相似文献
73.
74.
Arterial spin labeling (ASL) imaging is a powerful magnetic resonance imaging technique that allows to quantitatively measure blood perfusion non-invasively, which has great potential for assessing tissue viability in various clinical settings. However, the clinical applications of ASL are currently limited by its low signal-to-noise ratio (SNR), limited spatial resolution, and long imaging time. In this work, we propose an unsupervised deep learning-based image denoising and reconstruction framework to improve the SNR and accelerate the imaging speed of high resolution ASL imaging. The unique feature of the proposed framework is that it does not require any prior training pairs but only the subject's own anatomical prior, such as T1-weighted images, as network input. The neural network was trained from scratch in the denoising or reconstruction process, with noisy images or sparely sampled k-space data as training labels. Performance of the proposed method was evaluated using in vivo experiment data obtained from 3 healthy subjects on a 3T MR scanner, using ASL images acquired with 44-min acquisition time as the ground truth. Both qualitative and quantitative analyses demonstrate the superior performance of the proposed txtc framework over the reference methods. In summary, our proposed unsupervised deep learning-based denoising and reconstruction framework can improve the image quality and accelerate the imaging speed of ASL imaging. 相似文献
75.
《Patient education and counseling》2022,105(6):1470-1487
ObjectiveTo identify health professionals' (HPs) perspectives on the role of hope and the main challenges faced when communicating with patients in palliative care (PC).MethodsSearch on PubMed, Scopus, SocIndex, Cochrane, and Web of Science using: palliat*, palliative care, palliative medicine, hospice care, terminal care, long term care, supportive care, end of life (EOL) care and hope*, followed by a thematic narrative analysis.ResultsThirty-five studies were included. HPs' views were grouped in: Bringing out hope and Taking down hope. HPs believe that hope is elicited through a personal patient-provider bond and exhibited through medical treatment delivery. HPs face difficulties when delivering prognosis, referring to hospice, and providing palliation.ConclusionHope is conveyed through verbal and non-verbal communication. HPs struggle to account for hope's shifting character, challenging the engagement in EOL discussions.Practical implicationsFindings show a patient-provider clash of perspectives, suggesting a gap in acknowledging the shifting nature of hope. An important question emerges: Are the existing theories of hope that are solely explained from a patient experience relevant for HPs' own interpretation? Investigating the HPs' attitudes gathered in collective experiences in PC, might contribute to answering the question in the context of building more constructive communication approaches. 相似文献
76.
Sibylle M. Winter Katja Dittrich Peggy Dörr Judith Overfeld Imke Moebus Elena Murray Gergana Karaboycheva Christian Zimmermann Andrea Knop Manuel Voelkle Sonja Entringer Claudia Buss John-Dylan Haynes Elisabeth B. Binder Christine Heim 《Journal of child psychology and psychiatry, and allied disciplines》2022,63(9):1027-1045
77.
78.
Pharmaceutical compounds (PCs) have globally emerged as a significant group of environmental contaminants due to the constant detection of their residues in the environment. The main scope of this review is to fill the void of information on the knowledge on the African occurrence of selected PCs in environmental matrices in comparison with those outside Africa and their respective toxic actions on both aquatic and non-aquatic biota through ecotoxicity bioassays. To achieve this objective, the study focused on commonly used and detected pharmaceutical drugs (residues). Based on the conducted literature survey, Africa has the highest levels of ciprofloxacin, sulfamethoxazole, lamivudine, acetaminophen, and diclofenac while Europe has the lowest of all these PC residues in her physical environments. For ecotoxicity bioassays, the few data available are mostly on individual groups of pharmaceuticals whereas there is sparsely available data on their combined forms. 相似文献
79.
目的探究合并滑动性食管裂孔疝的Barrett食管患者经腹腔镜下治疗后生活质量和食管黏膜病变的改善情况。 方法回顾性收集首都医科大学宣武医院胃食管反流中心2016年1月至2020年12月诊断为Barrett食管伴滑动性食管裂孔疝患者23例,接受腹腔镜食管裂孔疝修补+胃底折叠术,于术前和术后12周时行胃镜、胃食管反流病自测量表(Gerd Q)评分、反流症状指数(RSI)评分、健康调查量表36(SF-36)调查问卷,评估患者术后生活质量和食管黏膜改善情况。 结果23例伴滑动性食管裂孔疝的Barrett患者术后12周随访显示3例患者黏膜病变部分消退。患者术后GerdQ、RSI相较术前均有明显改善(GerdQ:5.78±1.54 vs 11.65±1.50,P=0.00;RSI:9.70±1.92 vs 18.57±3.01,P=0.00),SF-36量表仅在生理功能方面改善不明显(85.87±4.16 vs 86.43±3.12,P=0.31),生理职能、情感职能、活力、精神健康、社会功能、躯体疼痛和总体健康方面均明显改善(生理职能:66.43±6.13 vs 35.48±2.86,P=0.00;情感职能:73.74±4.91 vs 65.22±2.58,P=0.00;活力:56.96±3.80 vs 50.30±4.56,P=0.00;精神健康:62.09±4.89 vs 53.26±2.07,P=0.00;社会功能:81.39±4.42 vs 74.00±3.59,P=0.00;躯体疼痛:80.00±6.84 vs 75.30±10.27,P=0.00;总体健康:69.17±5.68 vs 60.17±4.61,P=0.00)。 结论腹腔镜食管裂孔疝修补+胃底折叠术对伴滑动性食管裂孔疝的Barrett食管患者生活质量和黏膜病变均有一定改善。 相似文献
80.