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   6879篇
  免费   453篇
  国内免费   146篇
耳鼻咽喉   15篇
儿科学   168篇
妇产科学   111篇
基础医学   340篇
口腔科学   39篇
临床医学   1100篇
内科学   964篇
皮肤病学   33篇
神经病学   335篇
特种医学   268篇
外国民族医学   5篇
外科学   872篇
综合类   1015篇
现状与发展   2篇
预防医学   429篇
眼科学   36篇
药学   1004篇
  6篇
中国医学   140篇
肿瘤学   596篇
  2024年   11篇
  2023年   78篇
  2022年   113篇
  2021年   195篇
  2020年   180篇
  2019年   169篇
  2018年   157篇
  2017年   186篇
  2016年   184篇
  2015年   213篇
  2014年   423篇
  2013年   457篇
  2012年   429篇
  2011年   442篇
  2010年   389篇
  2009年   347篇
  2008年   330篇
  2007年   308篇
  2006年   314篇
  2005年   281篇
  2004年   233篇
  2003年   196篇
  2002年   172篇
  2001年   148篇
  2000年   150篇
  1999年   109篇
  1998年   94篇
  1997年   89篇
  1996年   82篇
  1995年   91篇
  1994年   69篇
  1993年   69篇
  1992年   73篇
  1991年   69篇
  1990年   50篇
  1989年   49篇
  1988年   52篇
  1987年   45篇
  1986年   47篇
  1985年   64篇
  1984年   55篇
  1983年   27篇
  1982年   44篇
  1981年   30篇
  1980年   29篇
  1979年   37篇
  1978年   25篇
  1977年   17篇
  1976年   15篇
  1975年   11篇
排序方式: 共有7478条查询结果,搜索用时 296 毫秒
121.
目的探讨百特泵持续静脉输注5-Fu联合化疗的近期疗效、不良反应和护理效果。方法将我院肿瘤科2011年3月至2013年11月接受百特泵持续静脉输注5-Fu和间歇静脉输注5-Fu两种联合化疗的病人分为治疗组和对照组,对比研究两组患者的满意度、疗效、体质状况、药物毒副反应间的差异。结果治疗组患者满意度、体质状况改善以及消化道反应和周围静脉炎的副作用较对照组减低,并有统计学意义(P<0.05);而在疗效、骨髓抑制和神经毒性方面无统计学差异(P>0.05)。结论百特泵持续静脉输注5-Fu联合化疗近期疗效满意,患者耐受性好,毒副反应减轻,化疗过程中须加强综合护理措施。  相似文献   
122.
123.
The interplay existing between immune reconstitution and patient outcome has been extensively demonstrated in allogeneic hematopoietic stem cell transplantation. One of the leading causes of infection-related mortality is the slow recovery of T-cell immunity due to the conditioning regimen and/or age-related thymus damage, poor naïve T-cell output, and restricted T-cell receptor (TCR) repertoires. With the aim of improving posttransplantation immune reconstitution, several immunotherapy approaches have been explored. Donor leukocyte infusions are widely used to accelerate immune recovery, but they carry the risk of provoking graft-versus-host disease. This review will focus on sophisticated strategies of thymus function-recovery, adoptive infusion of donor-derived, allodepleted T cells, T-cell lines/clones specific for life-threatening pathogens, regulatory T cells, and of T cells transduced with suicide genes.  相似文献   
124.
Allogeneic hematopoietic stem cell transplantation (alloHSCT) produces –similar to the long-established graft-versus-leukemia effect– graft-versus-solid-tumor effects. Clinical trials reported response rates of up to 53%, occurring mostly but not invariably in association with full donor chimerism and/or graft-versus-host disease. Although donor-derived T cells are considered the principal effectors of anti-tumor immunity after alloHSCT or donor leukocyte infusion (DLI), growing evidence indicate that recipient-derived immune cells may also contribute. Whereas the role of recipient-derived antigen-presenting cells in eliciting graft-versus-host reactions and priming donor T cells following DLI is well known, resulting inflammatory responses may also break tolerance of recipient effector cells towards the tumor. Additionally, mouse studies indicated that post-transplant recipient leukocyte infusion produces anti-leukemia and anti-solid-tumor effects that were exclusively mediated by recipient-type effector cells, without graft-versus-host disease. Here, we review current preclinical and clinical evidence on graft-versus-solid-tumor effects and growing evidence on the effector role of recipient-derived immune cells in the anti-tumor effect of alloHSCT.  相似文献   
125.
《Nanotoxicology》2013,7(6):783-794
Abstract

Protein coronas on nanoparticles (NPs) affect their physicochemical properties, cellular uptake, and toxicity, and have been described extensively. To date, studies of the occurrence of small molecule (metabolite) coronas are limited. We sought to determine whether a metabolite corona forms on NPs, using high-sensitivity metabolomics combined with a model system for freshwater ecotoxicology (Daphnia magna feeding on Chlorella vulgaris). Using amino-functionalized polystyrene NPs (NH2-pNPs), we showed the impact of this material on Daphnia feeding to provide a rationale for the detailed molecular investigations. We then employed a targeted LC-MS/MS approach for sodium dodecyl sulfate (SDS) as an analog to signaling molecules known to occur in our freshwater model system and optimized a corona extraction method for this representative metabolite. Next, we performed an untargeted discovery-based metabolomics study – using high-sensitivity nanoelectrospray direct infusion mass spectrometry (DIMS) – to enable an unbiased assessment of the metabolite corona of NH2-pNPs in the freshwater model system. Our results demonstrate that SDS was successfully recovered from NH2-pNPs, confirming that the extraction protocol was fit-for-purpose. Untargeted DIMS metabolomics reproducibly detected 100?s of small molecule peaks extracted from NH2-pNPs exposed to conditioned media from the D. magna–C. vulgaris model system. Attempts to annotate these extracted metabolites, including by using van Krevelen and Kendrick Mass Defect plots, indicate a diverse range of metabolites that were not clustered into any particular class. Overall we demonstrate the existence of an ecologically relevant metabolite corona on the surface of NPs through application of a high-sensitivity, untargeted mass spectrometry metabolomics workflow.  相似文献   
126.
Intravenous infusion over long periods is an increasingly common method of administration for novel medicinal agents. This investigation was undertaken to evaluate the suitability of a new catheter implantation technique in the rat and to determine the effects of two different infusion fluids and volumes on litter parameters. Female Sprague-Dawley rats were anesthetized on day 1 of gestation and an indwelling catheter was implanted into the posterior vena cava by introduction into the femoral vein. A swivel joint in the roof of the cage allowed unrestricted movement of the animal. One group of rats was not treated further. Other groups were maintained on continuous infusion with physiological saline or isotonic glucose (dextrose) solution at various rates until day 15 of gestation (the test article would normally be dissolved in the infusion fluid starting from day 6 of gestation). Anesthesia and catheter implantation without infusion caused a slight transient reduction in maternal weight gain by comparison with historical data from untreated rats. This parameter then showed a clear inverse relationship to infusion volume in the infused groups. An infusion rate of 0.25 mL/h (i.e., 24 mL/kg day?1) did not adversely affect gestation. Infusion of 1.0 mL/h of saline caused an increase in early resorption incidence and retarded fetal development. The same volume of isotonic glucose solution caused only a minor increase in resorptions with no effects on surviving fetuses.  相似文献   
127.
128.
129.
130.
When we are interested in making decisions about best use, comparative therapeutic efficacy, or cost-effectiveness of diabetes technologies such as insulin pump therapy [continuous subcutaneous insulin infusion (CSII)] or continuous glucose monitoring, meta-analysis for the purpose of literature summary is inappropriate and may be misleading. Instead, “decision-making meta-analysis” is more appropriate and should involve either preselection of trials based on intended use [e.g., elevated baseline hemoglobin A1c or hypoglycemia rate for trials of multiple daily injections (MDI) versus CSII] or metaregression of summary effect sizes in different trials against potential effect-modifying covariates such as baseline risk, or models of the covariates that determine effect size using individual patient data. Appropriate meta-analysis should also only include trials that are of sufficient duration to accurately measure outcomes such as severe hypoglycemia, and they should not use obsolete technology that is of proven inferiority to current technology. The use of appropriate decision-making meta-analysis is illustrated by the change in the rate ratio for severe hypoglycemia in randomized controlled trials of MDI versus CSII in type 1 diabetes from 1.56 (95% confidence interval 0.96–2.55; p = .074) for literature-summary meta-analysis to 2.0 (1.08–3.69; p = .027) for decision-making meta-analysis of all patients and 3.91 (1.35–11.36; p = .01) for trials in children.  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