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   20494篇
  免费   1674篇
  国内免费   534篇
耳鼻咽喉   161篇
儿科学   198篇
妇产科学   610篇
基础医学   1399篇
口腔科学   716篇
临床医学   2512篇
内科学   1321篇
皮肤病学   118篇
神经病学   531篇
特种医学   905篇
外国民族医学   1篇
外科学   2507篇
综合类   3868篇
一般理论   5篇
预防医学   2610篇
眼科学   466篇
药学   2446篇
  68篇
中国医学   1899篇
肿瘤学   361篇
  2024年   58篇
  2023年   470篇
  2022年   679篇
  2021年   1038篇
  2020年   985篇
  2019年   763篇
  2018年   764篇
  2017年   858篇
  2016年   860篇
  2015年   835篇
  2014年   1734篇
  2013年   1966篇
  2012年   1505篇
  2011年   1587篇
  2010年   1177篇
  2009年   1022篇
  2008年   992篇
  2007年   921篇
  2006年   789篇
  2005年   624篇
  2004年   500篇
  2003年   421篇
  2002年   313篇
  2001年   263篇
  2000年   226篇
  1999年   183篇
  1998年   147篇
  1997年   140篇
  1996年   108篇
  1995年   107篇
  1994年   85篇
  1993年   64篇
  1992年   81篇
  1991年   55篇
  1990年   56篇
  1989年   34篇
  1988年   44篇
  1987年   46篇
  1986年   36篇
  1985年   29篇
  1984年   22篇
  1983年   19篇
  1982年   20篇
  1981年   17篇
  1980年   15篇
  1979年   9篇
  1978年   5篇
  1977年   9篇
  1976年   8篇
  1974年   5篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
1.
目的 研究凉血通瘀方对高血压大鼠急性脑出血模型脑组织miRNA表达的影响,对差异表达的miRNA靶基因进行分析,探索凉血通瘀方可能的药效机制。方法 将自发性高血压大鼠随机分成对照组(B)和实验组(C)。适应性饲养一周后,C组灌胃凉血通瘀方,B组灌胃等体积生理盐水,连续5天,每天1次。构建脑出血模型后收集脑组织,借助全转录组测序技术获得miRNA表达量,与miRBase数据库比对获取已知miRNA,使用miRDeep2预测新miRNA。差异分析软件为DESeq2,筛选阈值为|log2FC| ≥1 并且P <0.05。对显著差异表达的miRNA进行靶基因预测,对靶基因进行GO功能、KEGG通路富集和PPI网络分析。结果 实验组和对照组对比,共发现21个显著差异表达的miRNA,上调有9个,下调有12个,共预测得到1243个有统计学意义的靶基因。GO富集分析发现,生物过程中突触囊泡分泌的调节、神经递质分泌的调节和神经递质运输的调节占前三位,神经元投射终点、全膜、质膜区域和细胞投射则是主要的细胞成分。分子功能分别为小GTPase绑定、底物特异性跨膜转运蛋白活性和离子跨膜转运体活性。通路分析结果显示,靶基因在癌证通路、pI3K-Akt信号通路、人类乳头瘤病毒感染、神经活性配体-受体相互作用和MAPK通路等分布广泛。采用STRING网站和Cytoscape软件,根据MCC算法筛选出ADRA2C、CASR、CCL28、CCR1、DRD2、GNAT3、GRM2、DYNC1LI1、GABBR1、GNAI1等核心靶基因。结论 凉血通瘀方对脑出血急性期鼠脑组织内miRNA的表达有重要影响;显著差异表达miRNAs可能通过靶向核心基因调控凉血通瘀方干预急性脑出血的病理过程及预后。  相似文献   
2.
前列腺癌(prostate cancer, PCa)是中老年男性常见恶性肿瘤之一,目前尚缺乏有效的晚期癌症治疗方法,因此早期诊断对于降低PCa死亡率至关重要。近年来,较多研究开发出多种新型诊断方法以改善对PCa诊断的准确性,同时避免过度诊疗,但其有效性及实用性尚需进一步验证。本文对目前新型生物标志物、联合成像技术及风险预测模型等的早期诊断技术进行总结,以期为临床研究提供指导作用。  相似文献   
3.
《Value in health》2022,25(12):1958-1966
ObjectivesNational health technology assessments (HTAs) across Europe show differences in evidentiary requirements from assessments by the European Medicines Agency (EMA), affecting time to patient access for drugs after marketing authorization. This article analyzes the differences between EMA and HTA bodies’ evidentiary requirements for oncology drugs and provides recommendations on potential further alignment to minimize and optimally manage the remaining differences.MethodsInterviews were performed with representatives and drug assessment experts from EMA and HTA bodies to identify evidentiary requirements for several subdomains and collect recommendations for potentially more efficiently addressing differences. A comparative analysis of acceptability of the evidence by EMA and the HTA bodies and for potential further alignment between both authorities was conducted.ResultsAcceptability of available evidence was higher for EMA than HTA bodies. HTA bodies and EMA were aligned on evidentiary requirements in most cases. The subdomains showing notable differences concerned the acceptance of limitation of the target population and extrapolation of target populations, progression-free survival and (other) surrogate endpoints as outcomes, cross-over designs, short trial duration, and clinical relevance of the effect size. Recommendations for reducing or optimally managing differences included joint early dialogues, joint relative effectiveness assessments, and the use of managed entry agreements.ConclusionsDifferences between assessments of EMA and HTA bodies were identified in important areas of evidentiary requirements. Increased alignment between EMA and HTA bodies is suggested and recommendations for realization are discussed.  相似文献   
4.
目的 比较改良眶隔法和传统睑板法切开重睑术中的应用效果及对术后重睑形态、瘢痕发生率、角膜暴露率的影响。方法 选取2020年3月-2021年3月首都医疗爱育华医院收治的80例单睑患者,采用随机数字表法将其分对照组和观察组,各40例。对照组接受传统睑板法切开重睑术,观察组接受改良眶隔法切开重睑术,比较两组术后重睑形态、瘢痕发生率、角膜暴露率、并发症发生率。结果 观察组总有效率高于对照组,差异有统计学意义(P<0.05);观察组GAIS评分高于对照组,VAS评分低于对照组,差异有统计学意义(P<0.05);观察组右侧角膜暴露率增加值、左侧角膜暴露率增加值高于对照组,差异有统计学意义(P<0.05);观察组并发症发生率为5.00%,低于对照组的22.50%,差异有统计学意义(P<0.05)。结论 相比于传统睑板法切开重睑术,改良眶隔法切开重睑术不会过度增加术后角膜暴露率,术后瘢痕发生率更低,重睑形态更理想,患者接受度更高。  相似文献   
5.
ObjectivesThis review analyzes the experiences of patients and clinicians with regards to international cross-border reproductive care (CBRC) for the purpose of conception.MethodsElectronic databases PubMed, Embase, Web of Science, and Scopus were searched using ‘medical tourism’ AND ‘assisted reproductive technology’ from 1978 to 2020.ResultsPredominant patient motivators for CBRC were cost and legality of assisted reproduction technology (ART) in one's home country, followed by cultural factors like shared language, religion, and cultural familiarity. Clinicians suggested global laws for CBRC would reduce the potential for exploitation of vulnerable populations but believed the enactment of international regulations unlikely and, even if enacted, difficult to enforce.ConclusionsWhile patient and clinician experiences with CBRC varied, patients frequently cited financial and legal reasons for pursuing CBRC, while many providers had concern for the patient’s safety.Clinical practice implicationsThis review recommends clinicians involved in family planning counsel patients seeking treatment abroad by: (i) informing patients of the risks and benefits of treatment abroad, (ii) establishing guidelines and standards for clinicians on resuming patient care post-CBRC, and (iii) creating a directory of reputable CBRC clinicians and experts.  相似文献   
6.
Anthrax is a zoonotic infection caused by the gram-positive, aerobic, spore-forming bacterium Bacillus anthracis. Depending on the origin of the infection, serious health problems or mortality is possible. The virulence of B. anthracis is reliant on three pathogenic factors, which are secreted upon infection: protective antigen (PA), lethal factor (LF), and edema factor (EF). Systemic illness results from LF and EF entering cells through the formation of a complex with the heptameric form of PA, bound to the membrane of infected cells through its receptor. The currently available anthrax vaccines have multiple drawbacks, and recombinant PA is considered a promising second-generation vaccine candidate. However, the inherent chemical instability of PA through Asn deamidation at multiple sites prevents its use after long-term storage owing to loss of potency. Moreover, there is a distinct possibility of B. anthracis being used as a bioweapon; thus, the developed vaccine should remain efficacious and stable over the long-term. Second-generation anthrax vaccines with appropriate adjuvant formulations for enhanced immunogenicity and safety are desired. In this article, using protein engineering approaches, we have reviewed the stabilization of anthrax vaccine candidates that are currently licensed or under preclinical and clinical trials. We have also proposed a formulation to enhance recombinant PA vaccine potency via adjuvant formulation.  相似文献   
7.
 异质性耐药是一种特殊的细菌耐药类型,常表现为同一克隆来源的不同细菌亚群对某种抗菌药物表现出不一致的耐药特征,大多数亚群对某种抗菌药物敏感,而少部分亚群对其耐药或高度耐药。异质性耐药分离株常会导致特定抗菌药物抗感染治疗失败。针对异质性耐药菌较为深入的研究主要集中于革兰阴性菌,革兰阳性球菌的相关报道较少。近年有研究报道万古霉素、利奈唑胺、苯唑西林等多种类型抗菌药物异质性耐药金黄色葡萄球菌分离株出现,但其实际临床意义尚待进一步评估。此文对金黄色葡萄球菌异质性耐药机制和检测技术最新进展进行综述,为细菌异质性耐药机制研究和新型检测技术研发提供新的思路。  相似文献   
8.
《Value in health》2022,25(9):1480-1488
ObjectivesInvolvement of patients and medical professionals in assessment of relative effectiveness (relative effectiveness assessment) contributes to an efficient and effective health technology assessment (HTA) process and supports acceptance and implementation of the outcome. This study aimed to analyze stakeholder involvement in assessing relative effectiveness and how the parties involved value this collaboration.MethodsThis is a document analysis of all drug assessments completed in 2019 (20) by the public HTA agency of The Netherlands, enriched with semistructured interviews with employees of the HTA agency (18) and representatives of patient (5) and medical (11) associations involved in these assessments. Data were analyzed, coded, and categorized.ResultsIn almost half of the assessments, there was no coordination with the medical associations at the start of the relative effectiveness assessment and no patient associations involved in this phase. During the assessment procedure, patient and medical associations were always asked to comment on the draft report. Nevertheless, the strict 5-day deadline that the HTA agency uses as a response period often hampered a proper response and involvement. According to interviewees of the HTA agency, this leads to a great diversity in the substantive quality of their input. Patient and medical associations indicated that the HTA agency relies too much on “paper knowledge,” which leads to a (perceived) lack of alignment with clinical practice.ConclusionsThe limited involvement results in a lack of coordination and mutual trust. Optimizing involvement of patients and medical professionals in HTA practice requires effort from all parties involved. Procedural adjustments and better coordination, especially at the start of the assessment, would probably improve cooperation.  相似文献   
9.
在过去的近40年里,直肠癌的治疗方案逐渐标准化。大多数早期直肠癌患者仅通过手术即可得到充分的治疗。然而,相当比例的直肠癌患者处于局部进展期,此类患者需要行新辅助治疗。直肠癌的新辅助放射治疗已被证明能有效地降低患者术前肿瘤分期、改善患者生存以及降低直肠癌局部复发率等,随之而来的是患者放疗后出现的不同程度的放疗不良反应,但随着放射治疗规范化、放射治疗技术及设备的改进,放疗不良反应严重程度在逐渐降低。本文就新辅助放疗中的放疗方案的选择、放射治疗技术、放疗不良反应、放疗后的手术时间以及放疗后的观察与等待等问题的最新研究进展进行了系统性的综述,从而为临床直肠癌新辅助治疗提供有力依据。  相似文献   
10.
吴江  陈吉华 《口腔医学》2022,42(5):385-390
数字化技术的发展为可摘局部义齿/全口义齿的设计和制作提供了全新的选择,具有高精度、高质量和高效率的特点。其中,本文就数字化印模、数字化设计与数字化制作这三个关键因素进行了重点讨论。  相似文献   
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