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   432篇
  免费   30篇
  国内免费   11篇
耳鼻咽喉   3篇
儿科学   7篇
妇产科学   2篇
基础医学   94篇
口腔科学   5篇
临床医学   41篇
内科学   54篇
皮肤病学   6篇
神经病学   11篇
特种医学   22篇
外科学   39篇
综合类   49篇
预防医学   28篇
眼科学   8篇
药学   58篇
中国医学   11篇
肿瘤学   35篇
  2024年   1篇
  2023年   6篇
  2022年   11篇
  2021年   24篇
  2020年   18篇
  2019年   12篇
  2018年   15篇
  2017年   11篇
  2016年   21篇
  2015年   13篇
  2014年   28篇
  2013年   48篇
  2012年   30篇
  2011年   32篇
  2010年   25篇
  2009年   22篇
  2008年   21篇
  2007年   22篇
  2006年   16篇
  2005年   19篇
  2004年   15篇
  2003年   5篇
  2002年   8篇
  2001年   8篇
  2000年   5篇
  1999年   4篇
  1998年   3篇
  1997年   4篇
  1996年   3篇
  1995年   2篇
  1994年   3篇
  1993年   2篇
  1992年   3篇
  1991年   1篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1986年   1篇
  1985年   2篇
  1982年   1篇
  1978年   2篇
  1977年   1篇
排序方式: 共有473条查询结果,搜索用时 46 毫秒
51.
目的研究褐藻胶对小鼠脾淋巴细胞Th1/Th2细胞因子谱的影响。方法体内实验:分别设阴性对照组和两个褐藻胶组(0.50g/kgbw和1.50g/kgbw),每组各5只C57BL/6小鼠,分别经口给予纯净水和褐藻胶,30天后分离脾淋巴细胞,培养48h后取上清采用流式微球分析术(CBA)方法分析白细胞介素(IL-2、IL-4、IL-5)、肿瘤坏死因子(TNF)和干扰素-γ(IFN-γ)水平。体外实验:分离C57BL/6种小鼠脾淋巴细胞,与褐藻胶(25mg/ml和50mg/ml)培养48h后取上清采用CBA方法分析IL-2、IL-4、IL-5、TNF和IFN-γ水平。结果体内实验:0.5g/kgbw和1.5g/kgbw褐藻胶组IFN-γ表达水平明显高于阴性对照组(P<0.01),而IL-2和IL-4表达水平下降(P<0.01,P<0.05)。体外实验:25mg/ml和50mg/ml褐藻胶组TNF、IL-2和IL-4表达均明显高于阴性对照组(P<0.05,P<0.01),50mg/ml褐藻胶组IL-5表达水平明显高于阴性对照组(P<0.01)。结论无论是在体内还是体外实验条件下,褐藻胶对小鼠脾淋巴细胞分泌的Th1/Th2细胞因子谱均有影响。  相似文献   
52.
53.
Chemical closure of chronic tympanic membrane perforations   总被引:1,自引:0,他引:1  
BACKGROUND: The purposes of closing chronic dry perforations of the tympanic membrane are to improve hearing and prevent middle ear infections. Before the use of the operating microscope and improved instrumentation, tympanic membrane perforations were closed by application of chemicals or with a temporary patch. Today, although surgery is the treatment of choice, small dry perforations may be successfully closed by chemical means in an office setting. METHODS: Twenty-eight of the 69 patients with chronic dry tympanic membrane perforations on the surgical waiting list at Hawke's Bay Regional Hospital, Hastings, New Zealand, underwent attempts at chemical myringoplasty. Two techniques were used: (i) cautery of the rim of the perforation with a silver nitrate bead on a metal probe and (ii) application of a urea ointment patch covering and overlapping the perforation. RESULTS: Eighteen of the 28 patients (64%) treated by chemical means experienced closure of their tympanic membrane perforations. Successful closure was achieved in 26% of the patients on the waiting list during the 6-month period. CONCLUSION: Chemical myringoplasty is not only of historical interest. It is an effective means of tympanic membrane closure in selected patients, thereby reducing the surgical waiting list and saving time and money for the patient, surgeon and hospital.  相似文献   
54.
There are no accepted methods to predict the development of platelet transfusion refractoriness (PTR) due to human leucocyte antigen (HLA)‐alloimmunization. Hence, matched platelets are usually given only to patients demonstrating PTR, necessarily resulting in some ineffective random donor platelets (RDPLT) transfusions. To assess its utility in predicting PTR, we retrospectively tested samples from 387 patients receiving chemotherapy for acute leukaemia or autologous transplantation using a micro‐bead flow cytometry assay. The average of the mean fluorescence intensities (avgMFI) of the class I beads in the screening assay was correlated with outcomes of RDPLT transfusions during a 2 week period. Antibodies were detected in 57 patients; 66 developed PTR, of whom 28 were alloimmunized. avgMFI usefully predicted the development of PTR (area under the receiver operating curve 0·87, 95% confidence interval: 0·77–0·96). A logistic regression model estimated the probability of PTR to be >90% when avgMFI >5440. These results indicate that micro‐bead flow cytometry assays could inform a risk‐adapted strategy for managing thrombocytopaenic HLA allo‐immunized patients.  相似文献   
55.
目的通过对霉素引起腹泻认识,指导临床合理用药。方法用便常规显微镜直接镜检:便少许加一滴等渗氯化钠液覆盖上玻片,置于显微镜下观察。芽管实验:于0.5ml人血清中加入便少许混匀37℃水浴2-3小时,直接涂片镜检。结果检验出大小不等卵圆形念珠菌,假菌丝,霉菌孢子;水浴2-3小时后,直接涂片镜检有芽管产生。结论合理应用抗生素以减少条件致病菌带来的二重感染,应引起人们重视  相似文献   
56.
应用材料科学和免疫学的新技术,我们在国内首次研制成功免疫磁性微珠(IMB)。在对一些临床常用血清指标以及两种激素标准品的免疫学定量检测中,自制IMB与瑞士Serono公司同类产品所获的结果十分接近(P<0.01),而且与放射免疫法的结果也有可比性(P<O.01)。自制IMB在用于免疫学检测时的特异性、精密度、重复性、准确性均符合质量控制要求。  相似文献   
57.
Purpose: To compare cytokines in undiluted vitreous of treatment‐naïve patients with macular oedema without vitreomacular traction secondary to branch (BRVO), central (CRVO) and hemi‐central (H‐CRVO) retinal vein occlusion. Methods: Ninety‐four patients (median age 72 years, 42 men) underwent an intravitreal combination therapy, including a single‐site 23‐gauge core vitrectomy and the application of bevacizumab and dexamethasone due to vision‐decreasing macular oedema. Among these were 43 patients with BRVO, 35 with CRVO and 16 patients with hemi‐CRVO, which were distributed in a fresh or old retinal vein occlusion type (seven or more months after onset). Undiluted vitreous samples were analysed for interleukin 6 (IL‐6), monocyte chemoattractant protein‐1 (MCP‐1) and vascular endothelial growth factor (VEGF‐A) with cytometric BEAD assay. Vitreous samples from patients with idiopathic epiretinal membrane served as controls (n = 14). Results: The mean cytokine values were highest in the CRVO group with IL‐6 = 64.7 pg/ml (SD ± 115.8), MCP‐1 = 1015.8 pg/ml (±970.1) and VEGF‐A = 278.4 pg/ml (±512.8), followed by the H‐CRVO group with IL‐6 = 59.9 pg/ml (SD ± 97.5), MCP‐1 = 938.8 pg/ml (±561.1) and VEGF‐A = 211.5 pg/ml (±232.4). The BRVO group had IL‐6 = 23.2 pg/ml (SD ± 48.8), MCP‐1 = 602.6 pg/ml (±490.3) and VEGF‐A = 161.8 pg/ml (±314.4). The values of MCP‐1 and VEGF‐A were significantly different for CRVO or H‐CRVO versus BRVO. All values were significantly higher than in the control samples, which had 6.2 ± 3.4 pg/ml (IL‐6), 253 ± 74 pg/ml (MCP‐1) and 7 ± 4.9 pg/ml (VEGF‐A). Within the old RVO type, only MCP‐1 was significantly different for CRVO or H‐CRVO versus BRVO. Conclusions: Both inflammatory markers and VEGF‐A were higher in CRVO and H‐CRVO than in BRVO undiluted vitreous samples. It seems that monocyte recruitment to the vessel wall, which might underlie the importance of eosinophils in tissue remodelling after RVO, is of special interest owing to the significant difference in MCP‐1 in the older RVO types.  相似文献   
58.
BackgroundIn patients undergoing heart transplantation, significant allosensitization limits access to organs, resulting in longer wait times and high waitlist mortality. Current desensitization strategies are limited in enabling successful transplantation.ObjectivesThe purpose of this study was to describe the cumulative experience of combined heart-liver transplantation using a novel heart-after-liver transplant (HALT) protocol resulting in profound immunologic protection.MethodsReported are the results of a clinical protocol that was instituted to transplant highly sensitized patients requiring combined heart and liver transplantation at a single institution. Patients were dual-organ listed with perceived elevated risk of rejection or markedly prolonged waitlist time due to high levels of allo-antibodies. Detailed immunological data and long-term patient and graft outcomes were obtained.ResultsA total of 7 patients (age 43 ± 7 years, 86% women) with high allosensitization (median calculated panel reactive antibody = 77%) underwent HALT. All had significant, unacceptable donor specific antibodies (DSA) (>4,000 mean fluorescence antibody). Prospective pre-operative flow cytometric T-cell crossmatch was positive in all, and B-cell crossmatch was positive in 5 of 7. After HALT, retrospective crossmatch (B- and T-cell) became negative in all. DSA fell dramatically; at last follow-up, all pre-formed or de novo DSA levels were insignificant at <2,000 mean fluorescence antibody. No patients experienced >1R rejection over a median follow-up of 48 months (interquartile range: 25 to 68 months). There was 1 death due to metastatic cancer and no significant graft dysfunction.ConclusionsA heart-after-liver transplantation protocol enables successful transplantation via near-elimination of DSA and is effective in preventing adverse immunological outcomes in highly sensitized patients listed for combined heart-liver transplantation.  相似文献   
59.
工业生产中得到广泛应用的可燃气体探测器主要有两种不同检测原理,即低温催化无焰燃烧和非色散红外吸收原理。文章分析了催化燃烧原理适应性、温度补偿的实现、线性输出的机理以及它依赖氧气、某些气体使其丧失催化性能等应用局限性;同时,分析红外吸收原理中红外波长的选择,光路、光源和吸收器等对探测器性能的影响;并指出两种原理各有特点和优点,针对不同场合正确选型,使可燃气体探测器可靠运行,保障环境安全。  相似文献   
60.
动脉化疗栓塞术(TACE)是中期肝癌患者的主要治疗方法。但是,由于这种技术存在着种种缺陷,比如药物局部释放的不可控制性、全身不良反应等,限制了其临床应用。而新出现的药物缓释微球(drug-eluting beads,DEB)可以负载着阿霉素应用于TACE中,不仅可以长时间维持化疗药物的局部浓度,达到更高的客观反应率,并且降低了不良反应的发生率,从而使患者获益。目前,药物缓释微球动脉化疗栓塞术(DEB-TACE)在国外已经得到了广泛的应用和推广,更多的相关临床试验也正在进行中。本文针对DEB-TACE的特性及最新研究进展予以综述。  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