首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   178596篇
  免费   13866篇
  国内免费   4165篇
耳鼻咽喉   1371篇
儿科学   2518篇
妇产科学   3064篇
基础医学   24081篇
口腔科学   3689篇
临床医学   12160篇
内科学   22113篇
皮肤病学   2211篇
神经病学   12174篇
特种医学   6399篇
外国民族医学   1篇
外科学   14412篇
综合类   24186篇
现状与发展   22篇
一般理论   8篇
预防医学   14572篇
眼科学   2231篇
药学   25848篇
  53篇
中国医学   12750篇
肿瘤学   12764篇
  2023年   2163篇
  2022年   3060篇
  2021年   6847篇
  2020年   6111篇
  2019年   6109篇
  2018年   6140篇
  2017年   6805篇
  2016年   6839篇
  2015年   6401篇
  2014年   7154篇
  2013年   11195篇
  2012年   9051篇
  2011年   11009篇
  2010年   6874篇
  2009年   6968篇
  2008年   8544篇
  2007年   9516篇
  2006年   9033篇
  2005年   8366篇
  2004年   7201篇
  2003年   6479篇
  2002年   5028篇
  2001年   4534篇
  2000年   3791篇
  1999年   3178篇
  1998年   2363篇
  1997年   2436篇
  1996年   2241篇
  1995年   2085篇
  1994年   2025篇
  1993年   1695篇
  1992年   1570篇
  1991年   1476篇
  1990年   1272篇
  1989年   1036篇
  1988年   993篇
  1987年   903篇
  1986年   832篇
  1985年   1230篇
  1984年   987篇
  1983年   744篇
  1982年   770篇
  1981年   629篇
  1980年   604篇
  1979年   480篇
  1978年   300篇
  1977年   259篇
  1976年   243篇
  1975年   186篇
  1974年   143篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
Major depressive disorder and other neuropsychiatric disorders are often managed with long-term use of antidepressant medication. Fluoxetine, an SSRI antidepressant, is widely used as a first-line treatment for neuropsychiatric disorders. However, fluoxetine has also been shown to increase the risk of metabolic diseases such as non-alcoholic fatty liver disease. Fluoxetine has been shown to increase hepatic lipid accumulation in vivo and in vitro. In addition, fluoxetine has been shown to alter the production of prostaglandins which have also been implicated in the development of non-alcoholic fatty liver disease. The goal of this study was to assess the effect of fluoxetine exposure on the prostaglandin biosynthetic pathway and lipid accumulation in a hepatic cell line (H4-II-E-C3 cells). Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes (Ptgs1, Ptgs2, and Ptgds), PPAR gamma (Pparg), and PPAR gamma downstream targets involved in fatty acid uptake (Cd36, Fatp2, and Fatp5) as well as production of 15-deoxy-Δ12,14PGJ2 a PPAR gamma ligand. The effects of fluoxetine to induce lipid accumulation were attenuated with a PTGS1 specific inhibitor (SC-560), whereas inhibition of PTGS2 had no effect. Moreover, SC-560 attenuated 15-deoxy-Δ12,14PGJ2 production and expression of PPAR gamma downstream target genes. Taken together these results suggest that fluoxetine-induced lipid abnormalities appear to be mediated via PTGS1 and its downstream product 15d-PGJ2 and suggest a novel therapeutic target to prevent some of the adverse effects of fluoxetine treatment.  相似文献   
32.
目的 观察张氏头针治疗儿童多发性抽动症的临床疗效。方法 2019年3月至2020年12月共招募多发性抽动症儿童60例,随机分为头针组和硫必利组,每组各30例。头针组采用毫针针刺双侧运动区、舞蹈震颤控制区及百会、印堂,每周治疗3次,1个月为1个疗程,共治疗4个疗程;硫必利组给予盐酸硫必利片50-100 mg/次,2次/天,1个月为1个疗程,共治疗4个疗程。比较两组患者治疗前后耶鲁综合抽动严重程度量表(Yale global Tic severity scale,YGTSS)、中医证候积分、SF-36健康调查简表(the MOS item short from health survey,SF-36)及临床疗效评价结果。结果 头针组合硫必利组组内比较:二组的YGTSS评分、中医证候积分与治疗前相比具有显著统计学差异(P<0.05),SF-36评分中头针组在生理功能、生理职能、总体健康、情感职能、心理健康等5个维度的评分高于治疗前,差异有统计学意义(P<0.05);硫必利组在生理功能、生理职能、总体健康、心理健康等5个维度的评分高于治疗前,差异有统计学意义(P<0.05);头针组合硫必利组组间比较:头针组治疗后YGTSS评分、中医证候积分均低于硫必利组,差异有统计学意义(P<0.05),头针组在SF-36量表中总体健康和心理健康2个维度照优于硫必利组,差异有统计学意义(P<0.05);治疗结束3个月随访,头针组YGTSS评分、中医证候积分均低于硫必利组,差异有统计学意义(P<0.05)。结论 张氏头针能够很好的改善多发性抽动症的临床症状,提高其生活质量。  相似文献   
33.
目的 运用科学知识图谱的手段,分析中医药治疗癫痫的研究进程并提炼重点。方法 设置检索时间为1990年至2020年,检索对象为中国知网(CNKI)该领域的相关文献,运用CiteSpace软件科学、准确地分析这些文献的作者信息、研究(发文)机构、关键词情况。结果 共计纳入文献793篇,马融-张喜莲、刘金民、谢炜、王洪图-张丽萍等领导核心作者团队,北京、广州以及广西中医药大学、天津中医药大学第一附属医院、南方医科大学等单位为主要进行相关研究的机构,高频关键词包括大鼠、难治性癫痫、小儿癫痫、海马、脑电图等,作用机制、网络药理学、肠道菌群、氧化应激、分子生物学等为近年来的热点与前沿。结论 通过借用知识图谱的分析能帮助提炼国内中医药治疗癫痫研究领域的重点,全面分析并科学判断近年来该领域的热点及前沿,为未来的研究夯实基础并把握方向。  相似文献   
34.
甲状腺癌是内分泌系统常见的恶性肿瘤之一,其发病率呈逐年上升趋势。甲状腺癌以分化型甲状腺癌(differentiated thyroid carcinoma, DTC)为主,尽管多数DTC患者经规范化治疗后预后良好,但由于部分肿瘤的病理类型侵袭性较高或肿瘤组织分化程度较低,病情进展迅速导致患者总生存时间显著缩短。近年来,有关炎症与肿瘤之间相关性的研究越来越多,炎性微环境的改变在肿瘤发病机制中的作用逐渐被证实,更多的证据表明细胞因子可作为肿瘤的良恶性鉴别、预后判断提示及诊疗方案选择等的重要参考依据。本文就部分细胞因子在DTC诊疗中的应用进展进行论述,旨在为DTC的诊疗与预后判断等提供参考依据。  相似文献   
35.
36.
《Vaccine》2022,40(31):4135-4141
Vaccination, health psychology and mental health make for three well-established and prestigious topoi in medical history. An in-depth look at their historical intersections remains forthcoming, however. Vaccinology’s psychological turns merit historians’ attention, all the more in the light of more recent, post-psychological and infodemiological, perspectives in vaccine acceptance research. Historiography at this point may help appreciating the present, and future, standing of psychological profiling in terms of its explanatory merits and policy uses. Of specific, critical interest is the motif of mental illness historically shared by vaccine advocates and contrarians. Mock-psychiatric nosology was a favored framing device for vaccination polemicists early on, indeed before vaccines were called vaccines and before psychiatry came to be called psychiatry. Though long anticipated, substantive historical-sociological and empirical approaches to vaccine non-acceptance were seen only from the 1920s and 1930s, respectively. Today, spirited animosity over vaccination continues to invite both professional and public debate about the founding concepts, the basic tenets, and the defining boundaries, of the mental health sciences.  相似文献   
37.
目的 探讨糖尿病前期的中医证型及证素分布特点。方法 检索中国知网、万方及维普三大数据库中收录的自建库以来有关糖尿病前期证型的临床研究文献,对中医证型进行规范整理,建立数据库,提取证素,运用数据挖掘技术中的关联分析、聚类分析探究证素分布规律。结果 共纳入10篇文献,总有效病例1620例,证型经规范处理后整理为18个,主要证型为脾虚痰湿证。共提取证素13个,主要病位证素为脾,主要病性证素为气虚、湿和痰,关联分析显示脾—湿支持度和置信度最高,聚类分析结果可得到3个聚类组。结论 糖尿病前期病位在脾,气虚、脾、痰、湿是常见证素,临床诊治糖尿病前期应注重从脾论治,需辨证施治。  相似文献   
38.
The aim of the study was to compare automated and manually conducted (slice-by-slice) virtual orbital wall reconstruction in terms of PSI design, manufacture, and clinical application for orbital fracture management.Patients with orbital wall fractures were evaluated for the potential for treatment with PSI, based on automated virtual wall reconstruction; these formed the main group. The surgical outcomes of these main-group patients' treatments were compared with those of the control group, which comprised patients randomly selected for this study, each of whom had the same orbital trauma patterns and were also managed with PSI. However, the control group patients were treated using ‘slice-by-slice’ virtual orbital reconstruction.Mean volume differences between the intact and reconstructed orbit were 0.65 ± 0.26 cm3 in the main group (n = 23) and 0.57 ± 0.23 cm3 in the control (n = 27; p = 0.837). In both groups, no cases of implant malposition or enophthalmos were detected after surgery. Orbital shape difference was similar for the main group and the control, at ?3.3 ± 3.5% and 3.25 ± 2.5%, respectively (p = 0.929). Diplopia was diagnosed at the 3-month follow-up in 13.0% of the main group and in 11.1% of the control (p = 0.651). The average times spent on computer-aided design (CAD) procedures, including segmentation, virtual orbital reconstruction, and PSI design, were 36.7 ± 6.9 min in the main group and 72.9 ± 7.7 min in the control group (p < 0.001).Within the limitations of the study it seems that PSI based on automated virtual reconstruction is a relevant alternative treatment option for orbital fractures because of its clinical efficacy that is similar to PSI based on a ‘slice-by-slice’ CAD protocol.  相似文献   
39.
《Saudi Dental Journal》2022,34(7):596-603
ObjectiveStudies have shown that gingival crevices may be a significant route for SARS-CoV-2 entry. However, the role of oral health in the acquisition and severity of COVID-19 is not known.DesignA retrospective analysis was performed using electronic health record data from a large urban academic medical center between 12/1/2019 and 8/24/2020. A total of 387 COVID-19 positive cases were identified and matched 1:1 by age, sex, and race to 387 controls without COVID-19 diagnoses. Demographics, number of missing teeth and alveolar crestal height were determined from radiographs and medical/dental charts. In a subgroup of 107 cases and controls, we also examined the rate of change in alveolar crestal height. A conditional logistic regression model was utilized to assess association between alveolar crestal height and missing teeth with COVID-19 status and with hospitalization status among COVID-19 cases.ResultsIncreased alveolar bone loss, OR = 4.302 (2.510 – 7.376), fewer missing teeth, OR = 0.897 (0.835–0.965) and lack of smoking history distinguished COVID-19 cases from controls. After adjusting for time between examinations, cases with COVID-19 had greater alveolar bone loss compared to controls (0.641 ± 0.613 mm vs 0.260 ± 0.631 mm, p < 0.01.) Among cases with COVID-19, increased number of missing teeth OR = 2.1871 (1.146– 4.174) was significantly associated with hospitalization.ConclusionsAlveolar bone loss and missing teeth are positively associated with the acquisition and severity of COVID-19 disease, respectively.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号