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   12117篇
  免费   918篇
  国内免费   61篇
耳鼻咽喉   53篇
儿科学   305篇
妇产科学   251篇
基础医学   1355篇
口腔科学   309篇
临床医学   1465篇
内科学   2264篇
皮肤病学   102篇
神经病学   1286篇
特种医学   385篇
外科学   1181篇
综合类   292篇
一般理论   14篇
预防医学   1581篇
眼科学   194篇
药学   1214篇
中国医学   9篇
肿瘤学   836篇
  2023年   48篇
  2022年   49篇
  2021年   215篇
  2020年   140篇
  2019年   238篇
  2018年   255篇
  2017年   208篇
  2016年   249篇
  2015年   261篇
  2014年   352篇
  2013年   519篇
  2012年   815篇
  2011年   800篇
  2010年   431篇
  2009年   419篇
  2008年   713篇
  2007年   769篇
  2006年   731篇
  2005年   793篇
  2004年   716篇
  2003年   645篇
  2002年   651篇
  2001年   238篇
  2000年   235篇
  1999年   225篇
  1998年   131篇
  1997年   111篇
  1996年   109篇
  1995年   90篇
  1994年   71篇
  1993年   83篇
  1992年   141篇
  1991年   108篇
  1990年   124篇
  1989年   89篇
  1988年   101篇
  1987年   91篇
  1986年   115篇
  1985年   93篇
  1984年   77篇
  1983年   72篇
  1982年   59篇
  1981年   51篇
  1980年   41篇
  1979年   63篇
  1978年   52篇
  1977年   36篇
  1974年   43篇
  1970年   42篇
  1968年   41篇
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
1.
BackgroundThe American Radium Society (ARS) Appropriate Use Criteria brain malignancies panel systematically reviewed (PRISMA [Preferred Reporting Items for Systematic Reviews and Meta-Analyses]) published literature on neurocognitive outcomes after stereotactic radiosurgery (SRS) for patients with multiple brain metastases (BM) to generate consensus guidelines.MethodsThe panel developed 4 key questions (KQs) to guide systematic review. From 11 614 original articles, 12 were selected. The panel developed model cases addressing KQs and potentially controversial scenarios not addressed in the systematic review (which might inform future ARS projects). Based upon quality of evidence, the panel confidentially voted on treatment options using a 9-point scale of appropriateness.ResultsThe panel agreed that SRS alone is usually appropriate for those with good performance status and 2–10 asymptomatic BM, and usually not appropriate for >20 BM. For 11–15 and 16–20 BM there was (between 2 case variants) agreement that SRS alone may be appropriate or disagreement on the appropriateness of SRS alone. There was no scenario (among 6 case variants) in which conventional whole-brain radiotherapy (WBRT) was considered usually appropriate by most panelists. There were several areas of disagreement, including: hippocampal sparing WBRT for 2–4 asymptomatic BM; WBRT for resected BM amenable to SRS; fractionated versus single-fraction SRS for resected BM, larger targets, and/or brainstem metastases; optimal treatment (WBRT, hippocampal sparing WBRT, SRS alone to all or select lesions) for patients with progressive extracranial disease, poor performance status, and no systemic options.ConclusionsFor patients with 2–10 BM, SRS alone is an appropriate treatment option for well-selected patients with good performance status. Future study is needed for those scenarios in which there was disagreement among panelists.  相似文献   
2.
Now is an exciting era of development in immunotherapy checkpoint inhibitors and their effect on the treatment of NPC. While the general prognosis of R/M disease is poor, immunotherapy offers some promise in a malignancy associated with EBV and characterized by a peritumoural immune infiltrate. Our study aims to review past and on-going clinical trials of monoclonal antibody therapies against the checkpoint inhibitors (e.g. PD1 and CTLA-4), in R/M NPC. All randomized and nonrandomized controlled trials involving immune checkpoint inhibitor interventions for treatment of NPC were included in the study. We utilized a validated “risk of bias” tool to assess study quality. Four separate Phase I–II trials report the potential of PD1 inhibitor treatment for patients with NPC. Within the observed groups, camrelizumab combined with chemotherapy achieved an objective response in 91% of patients as first-line treatment for metastatic NPC (PFS 68% at 1-year) but this was associated with a high rate of grade >3 adverse events (87%; CTCAE version 4.03). The remaining three studies focused on recurrent NPC disease in patients who had received at least one line of prior chemotherapy. Within this group, camrelizumab monotherapy achieved an objective response in 34% of patients (PFS 27% at 1-year; range across all three studies 20.5–34%). No NPC trial has yet reported on specific outcomes for non-PD1 checkpoint inhibitors but 11 on-going studies include alternative targets (e.g. PD-L1/CTLA-4) as combination or monotherapy treatments. In considering checkpoint immunotherapies for NPC, initial results show promise for anti-PD1 interventions. Further phase I–III trials are in progress to clarify clinical outcomes, fully determine safety profiles, and optimize drug combinations and administration schedules.  相似文献   
3.
4.
Pericardial involvement of multiple myeloma is a rare and late‐stage complication, with only a few cases reported in the literature. PET/CT has demonstrated a growing role in the diagnosis and follow‐up of patients with multiple myeloma. We present a case of pericardial multiple myeloma in a patient with relapsed/refractory disease, showcasing previously unpublished FDG PET/CT findings.  相似文献   
5.
Abstract

Children are considered a vulnerable group and as such are granted additional protection as research subjects. Research projects using children as research subjects are justifiable if the answer to the scientific question of the study cannot be obtained by enrolling adult subjects (cf. scientific necessity). Thus, there is an ethical obligation to explore innovative analytical strategies that seek balance between the feasibility of conducting a trial and maximizing the utilization of data on efficacy and safety. On this note, there is enthusiasm for implementing some less popular but efficient alternative designs for confirmatory pediatric trials. Within the pediatric extrapolation paradigm, examples of such designs, other than purely based on pharmacokinetic/pharmacodynamic data, are described in this article along with their advantages and disadvantages. This article will also discuss how to incorporate alternative data sources in the analysis of pediatric clinical trials. A discussion of existing approaches and a road-map to their utilization will be provided. Real case examples on the use of the approaches are provided.  相似文献   
6.
7.
8.
9.
10.

Background

Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.

Objectives

To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.

Methods

Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.

Results

Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.

Conclusions

These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study.  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