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51.
任杰 《科普研究》2012,7(6):77-84
本文遴选2006-2010年中英两国主流报纸对麻疹疫苗和MMR的新闻报道样本,采用内容分析方法以“科学的确定性与不确定”和“政府政策意见趋向”为主线分析了不同媒体环境下针对防治麻疹病疫苗的科学报道模式。通过比较研究中西方不同国家的政府、媒体以及科学家如何针对麻疹疫苗争议对公众进行正确健康疏导以及危机处理方式,拓展了科学普及的研究视野并试图从中总结出更加合理的科技报道模式。科学争议以及危机处理需要科学界与媒体正确的引导,随着网络科技报道数量的增加,传统媒体需要重视其他渠道的科技信息,尤其是来自于科学界的信息,从而对原有科技报道模式做出调整和改善。  相似文献   
52.
光动力法制备抗小鼠H22肝癌的肿瘤疫苗   总被引:1,自引:3,他引:1  
研究了光动力疗法(PDT)制备的抗小鼠H22肝癌肿瘤疫苗的抗瘤效应.将昆明鼠60只,随机分为2组,每组30只.实验组取6~12周龄的昆明鼠背部皮下接种光动力疗法产生的疫苗,每3天注射一次,每次注射50μL(相当于3×105个细胞),连续两周.隔一周于第22天注射H22肿瘤细胞悬液0.1 mL(1×106个细胞);对照组:每周每次注射50μL生理盐水,连续两周.隔一周于第22天注射H22肿瘤细胞悬液0.1 mL(1×106个细胞).比较两组的抑瘤率、生存率以及两组之间免疫学的相关指标.结果表明,实验组小鼠具有显著的抑瘤效果,抑瘤率、生存率较对照组有显著提高.实验组肿瘤抑瘤率最高可达60%且长期有效,100天生存率达56%.说明光动力疗法产生的抗小鼠H22肝癌疫苗可以有效地抑制肿瘤生长,提高荷瘤小鼠的生存率,具有明显的抗瘤效应.该方法可能成为一种辅助性治疗肿瘤的手段而应用于临床.  相似文献   
53.
本文基于生物免疫系统防御机制,探讨了将人工免疫原理应用于垃圾邮件过滤系统(IDSFS),通过动态生成垃圾邮件疫苗,提高系统的检出率.另外,针对传统邮件过滤系统存在的错误肯定率、错误否定率等不足及用户对邮件个性化处理的要求,引入用户反馈机制,使得系统精确率、正确率进一步提高.实验结果表明,该系统具有较强的自学习、自适应能力.  相似文献   
54.
Densely packed dry‐coated microprojections are shown to deliver vaccines to targeted locations within the skin that are rich in immune cells, thus inducing protective immune responses against a lethal virus challenge. Selectively limiting the antigen coating to the tips of the projections, which penetrate the skin, would significantly reduce the amount of vaccine required in immunization. In this paper a simple technique, dip‐coating the microprojections, is introduced to meet this goal. By increasing the coating solution viscosity, an otherwise strong capillary action is mitigated and the desired controlled coating length on projections is achieved. Following application to the skin, most of the coated vaccine material is rapidly released from the projections (82.6% in mass within 2 min) to the target locations within the skin strata and a potent immune response is induced when a conventional influenza vaccine (Fluvax) is tested in a mouse model. The utility of this coating approach to a variety of molecules representative of vaccines (e.g., chicken egg ovalbumin (OVA) protein, DNA, and fluorescent dyes) is demonstrated. These collective attributes, together with the simplicity of the approach, position the dip‐coating method for practical utility in large vaccination campaigns.  相似文献   
55.
随着各运营商之间竞争日趋激烈。为大客户提供方便、快捷.经济的服务是各运营商的首要目标。立即计费(IB)技术的实现.一方面使集团用户能够自主快捷地进行话费核算.电话权限控制.达到内部成本控制目的:另一方面.集团用户能在几乎没有投资成本的情况下实现PBX的功能,同时克服了PBX由于受到中继的约束.通话数量受限的瓶颈。  相似文献   
56.
In a recent update of the Dutch contingency plan for controlling outbreaks of classical swine fever (CSF), emergency vaccination is preferred to large-scale pre-emptive culling. This policy change raised two questions: can emergency vaccination be as effective as pre-emptive culling, and what are the implications for showing freedom of infection? Here, we integrate quantitative information available on CSF virus transmission and vaccination effects into a stochastic mathematical model that describes the transmission dynamics at the level of animals, farms and livestock areas. This multilevel approach connects individual-level interventions to large-scale effects. Using this model, we compare the performance of five different control strategies applied to hypothetical CSF epidemics in The Netherlands and, for each of these strategies, we study the properties of three different screening scenarios to show freedom of infection. We find that vaccination in a ring of 2 km radius around a detected infection source is as effective as ring culling in a 1 km radius. Feasible screening scenarios, adapted to the use of emergency vaccination, can reduce the enhanced risks of (initially) undetected farm outbreaks by targeting vaccinated farms. Altogether, our results suggest that emergency vaccination against CSF can be equally effective and safe as pre-emptive culling.  相似文献   
57.
本文论述了基于电话交换技术和智能网技术的虚拟专用电话网的构建,同时提出了基于IP技术和MPLS技术的虚拟专用数据网的构建方案。  相似文献   
58.
Human disease elicits a complex array of biological processes that results in long‐term protective immunological memory to infectious agents. Chronic kidney disease is known to impair induction of sustained immunological memory to hepatitis B vaccine (HBVax) antigens. We asked the question: Does end‐stage renal disease promote changes in subtypes of regulatory T (Treg) cells that correlate with diminished amnestic response to HBVax antigen compared to healthy controls? The study design and setting was a prospective observational cohort at a veterans affairs medical center. End‐stage renal disease patients on hemodialysis (HD) were compared with individuals with self‐reported normal kidney function. All subjects received HBVax. Peripheral blood was sampled for assessment for Treg cells pre and post vaccination. CD4+ FOXP3 Treg numbers were similar between HD and healthy subjects during a 14‐day time period post vaccination. HD subjcts had lower anti‐HBSag antibody than CON (control) subjects (330 ± 108.7 vs. 663.1 ± 129.7 IU/mL; P = 0.063). Hemodialysis subjects with resting Tregs higher than the median value in our cohort demonstrated a significantly lower change in HBsAB at 30 days post booster vaccination (P = 0.030). No such relationship was found for the activated Treg subset among HD subjects, or either subset among CON subsets. In our limited comparison study of 11 HD and 8 CON subjects, Treg subsets did not differ between the two groups; but differences in the suppressive Treg numbers in the HD group could explain the altered antibody response to HBVax and is worthy of further study.  相似文献   
59.
治疗性疫苗不仅具有预防性疫苗的间接靶向特异性和长效性等特点,而且还具有治疗性药物的疗效,尤其对一些目前尚无特效治疗药物的传染性疾病及肿瘤等可以起到治疗作用。近年来,治疗性疫苗的研究已取得了全面的进展。本文就治疗性疫苗的意义、作用机理及研究进展作一综述。  相似文献   
60.
目的探讨乙肝疫苗苦参素拉米夫定联合治疗慢性乙型肝炎的临床疗效。方法随机选择62例慢性乙型肝炎患者分为治疗组31例,苦参素0.2tidpo。疗程7~9个月,乙肝疫苗60ug,每15天1次,皮下注射,疗程12个月,拉米夫定0.1qdpo.疗程12个月。对照组31例单用拉米夫定0.1qdpo。疗程12个月。疗程中定期检测血常规、谷丙转氨酶(ALT)、HBeAg、抗-HBe、HBV、DNA。结果全部患者完成1年治疗。治疗组ALT复常率,HBeAg/抗-HBe血清转换率、HBVDNA阴转率明显高于对照组(分别为80.6%和51.6%,P<0.05;45.2%和19.4%,P<0.05;77.4%和51.6%,P<0.05)。结论乙肝疫苗、苦参素、拉米夫定联合治疗慢性乙型肝炎疗效优于单用拉米夫定。  相似文献   
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