物质安全评价学的构建研究

为完善安全物质学学科体系,有效利用物质本质安全特性,预防和控制物因事故发生,提出物质安全评价学定义,并从研究目的及研究对象等方面解析其内涵。根据其学科性质,从理论和应用两个方面建立包括物质风险评价理论、物质风险控制理论、物质健康风险评价、物质生态风险评价、物质事故风险评价5个分支的物质安全评价学研究内容体系。在此基础上,概述物质危害性辨识-物质风险分析-物质风险评估-物质风险控制四步骤的研究程序,并给出各程序的具体内容及研究方法。所做研究明确了物质安全评价学的基本学科体系,系统化了物质安全评价学的研究方法。     

生物多样性学发展中几个基本问题的探讨

近10年来,生物多样性科学的理论和方法取得了显著进展,高度交叉学科-“生物多样性学”孕育而生。但是,诸如生物多样性的生态系统功能、生物多样性与生态系统过程、生物多样性的测度、生物多样性的维持格局与丧失机制等一直是研究的热点和难点,仍在讨论和争论中发展。本文从生物多样性学的理念出发,对生物多样性研究中几个基本问题进行探讨,分析了生物多样性学框架的科学范畴。指出构建以生物多样性保育为核心目标的生物多样性学科体系和框架是生物多样性研究发展的必要。生物多样性学应始终重视实验研究和理论演绎,并不断重视哲学和思维过程。     

法国数学家塞尔荣获首届阿贝尔数学奖

挪威科学院日前在挪威首都奥斯陆宣布 ,把首届阿贝尔奖授予法国数学家让 -皮埃尔·塞尔 ,以表彰他在数学领域所作出的杰出贡献。在授奖决定中 ,挪威科学院称赞塞尔通过努力赋予了拓扑学、代数几何学和数字学等许多数学领域以“现代的形式” ,成为“当代最杰出的数学家之一”。今年 76岁的塞尔现为法国法兰西学院荣誉教授 ,并被许多国家的大学授予名誉博士头衔。阿贝尔奖是挪威政府 2 0 0 2年为纪念挪威天才数学家尼尔斯·亨利克·阿贝尔出资设立的一项数学大奖。阿贝尔在 5次方程和椭圆函数研究方面远远地走在了当时研究水平的前面 ,但因学…     

基于政府投入的美国再生医学研究态势分析

为掌握美国再生医学研究态势,本文对美国联邦政府资助的再生医学项目金额、数量、资助机制、资助对象、研究方向等内容进行统计与聚类分析,发现近年来资助项目的数量和金额整体呈上升趋势,类型以竞争性定向研究为主,兼顾人才培养、培训和基础设施建设,资助对象以高校为主。资助的再生医学研究可被划分为以干细胞、生物技术、神经科学、遗传学以及消化系统疾病为代表的5大研究领域,具体来看,干细胞研究、生物技术、遗传学受到持续关注,神经科学、罕见病、损伤、儿科等方向研究热度上升,相比之下,癌症、心脏病和脑病方向的研究热度降低。干细胞研究中,基于人类的干细胞研究资助增长趋势高于非人类干细胞研究。     

高纯球形纳米SiO2的制备、改性与应用研究

高纯球形纳米SiO_2是一种具有诸多优越性能的新型材料,对于诸多行业产品的提档升级具有极其重要的意义。本文综述了纳米SiO_2的制备及改性方法,对各种方法进行了归纳和评价,并对其应用领域作了简要概括。通过研究表明,以粉石英为基本原料,采用溶胶-凝胶法制备的纳米SiO_2具有纯度高、球形度高、成本低等特点。     

金属氧化物/石墨烯复合材料在气体传感领域的研究进展

作为一类重要的传感材料,半导体金属氧化物已被广泛应用于气体传感领域,其优异的电化学特性、催化特性以及阻抗变化特性使其适用于各种氧化-还原类的气体传感.同时,作为一种具有独特单原子层厚度的sp2碳原子杂化二维材料,石墨烯表现出独特的物理-化学特性,因此,基于石墨烯的复合材料成为近年来的研究热点.利用金属氧化物优异的气敏传感特性及石墨烯独特的电学、力学和热力学特性,将石墨烯/金属氧化物复合材料应用于气体传感领域已引起人们的极大兴趣.本文系统总结了近年来不同形貌、不同结构的金属氧化物/石墨烯复合材料在气体传感中的应用,列举了在检测同一种目标气体时不同金属氧化物/石墨烯复合材料传感性能的异同,归纳了金属氧化物修饰的石墨烯复合材料最新研究进展,并对金属氧化物/石墨烯复合材料在气体传感领域的研究趋势进行了展望.     

Garden:一种面向领域语言的集成开发环境

随着计算机技术的发展,通用语言已经不能满足各种领域应用程序开发的需要.由于领域语言提供领域专用术语和符号的概念,支持该领域中的各种处理,能够简洁、有效地构造该领域应用程序,因此,领域语言成为当前计算机语言研究中的热点.文中在面向模型的变换型软件开发方法和语言的抽象与封装机制研究的基础上,设计与实现了一种面向语言的领域语言的集成开发环境Garden,它包括软件开发环境和程序开发环境.软件开发环境以GarAda解释器为核心,用于支持领域语言开发的各过程;程序开发环境以领域语言编译器为核心,用于支持领域用户程序开发的各过程.Garden的研制成功,为领域语言的自动生成探索了一条切实可行的途径.     

安全民俗文化学的创立研究

为促进安全文化学研究的发展,开拓安全文化学研究新领域,基于民俗、民俗学、安全文化及安全文化学的定义,从民俗学和安全文化学角度,提出安全民俗文化与安全民俗文化学的定义,并分析安全民俗文化学的研究对象、研究目的、研究内容和研究方法等学科基本问题。基于此,剖析安全民俗文化学在安全文化学研究与安全宣教、安全管理3方面的广泛应用前景。结果表明,安全民俗文化学是安全文化学研究的一个新视角,其作为安全文化学的一个主要分支学科,研究内容丰富,研究方法独特,研究价值巨大。     

海洋沉积动力学研究与应用前景展望

海洋沉积动力学正在打破传统，走向海洋工程学、物理海洋学和地质学的联合，共同建立一门综合性的、统一的沉积动力学。其技术手段包括：悬沙输运的动力学模型方法、以力学为基础的半经验公式、经验公式、人工和天然示踪沉积物技术、地貌学信息方法、沉积学信息方法、以及现场直接观测。国际国内的研究动态均表明，这些方法的建立和完善将为海洋沉积动力学在海底地貌演化、生态系统的维护和改造、人类活动对环境影响的评估、海洋资源开发和持续发展战略制定等方面的应用 提供广阔的前景。     

城市轨道交通危险因素分析与评价

针对城市轨道交通影响安全因素众多的特点,本文从人-机-环-管理四方面出发,分析了城市轨道交通在建设及运营过程中存在的各种危险因素,并用层次分析法对各种危险因素进行了权重计算,得出了各种危险因素的排序。针对排序结果提出合理的预防和控制对策,从而为改善城市轨道交通安全状况,减少事故发生提供科学依据。     

Towards progress on DNA vaccines for cancer

Cancer immunotherapy faces many obstacles that include eliciting immune reactions to self antigens as well as overcoming tumor-derived immunosuppressive networks and evasion tactics. Within the vaccine arsenal for inhibiting cancer proliferation, plasmid DNA represents a novel immunization strategy that is capable of eliciting both humoral and cellular arms of the immune response in addition to being safely administered and easily engineered and manufactured. Unfortunately, while DNA vaccines have performed well in preventing and treating malignancies in animal models, their overall application in human clinical trials has not impacted cancer regression to date. Since the establishment of these early trials, progress has been made in terms of increasing DNA vaccine immunogenicity and subverting the suppressive properties of tumor cells. Therefore, the success of future plasmid DNA use in cancer patients will depend on combinatorial strategies that enhance and direct the DNA vaccine immune response while also targeting tumor evasion mechanisms. Received 2 April 2007; received after revision 14 May 2007; accepted 21 May 2007     

Immunoglobulin-binding proteins in ticks: new target for vaccine development against a blood-feeding parasite

Humans have a long history of trying to control ticks. At first, attempts focused on modifying the habitat, whereas later efforts relied heavily on the use of chemicals. Current research is directed at finding a vaccine against ticks. A strategy of targeting 'concealed antigens' succeeded with the first commercialised vaccine against the cattle tick Boophilus microplus. However, vaccine development against other tick species appears unsatisfactory to date. Vaccination depends on a specific antibody-mediated immunoreaction that damages the parasite. Immunoglobulin molecules of vertebrate hosts can pass through gut barriers into the haemolymph of ectoparasites while retaining antibody activity. Research on the ixodid tick Rhipicephalus appendiculatus revealed that host immunoglobulin-G in the parasite was excreted via salivation, during feeding. Immunoglobulin-binding proteins in tick haemolymph and salivary glands are thought to be responsible for such excretion. The discovery of an immunoglobulin excretion system in ticks indicates that they have a highly developed mechanism to protect themselves from their host's antibody attack. Such a mechanism questions whether immunization strategies will be effective against ticks, unless they circumvent or disable the ticks' immunoglobulin excretion system.     

Evaluation of oral vaccination against mouse-typhoid in a new animal model

Summary In a simple, new animal model the spread of mouse-typhoid within a mouse-colony was studied and oral vaccination against this disease was evaluated. Live vaccine was superior to inactivated vaccine.     

Retention of<Emphasis Type="Italic">B. burgdorferi</Emphasis> pathogenicity and infectivity after multiple passages in a co-culture system

In vitro cultivation ofB. burgdorferi in BSK medium results in the loss of infectivity and pathogenicity after repeated passages. To prevent this loss, a feeder layer of tibio-tarsal joint tissue derived from newborn LEW/N rats was grown on Cytodex 3 microcarriers in ESG (formerly BSKE), a novel medium developed to support the growth of both the feeder layer andB. burgdorferi. A new pathogenic isolate (FNJ) and a high passage, non-pathogenic strain (TNJ) grew well in this co-culture system with high yields of viable organism. FNJ caused no growth inhibition or visible damage to the cells in the feeder layer. FNJ remained arthritogenic for newborn LEW/N rats after 22 passages in the co-culture system, but lost its arthritogenicity after 7 passages when cultured in BSK medium. This borrelia-mammalian tissue co-culture technique presents an experimental system to study the long term interactions ofB. burgdorferi with the infected host tissues in vitro, as well as facilitate diagnostic tests and vaccine development.     

Display of proteins on Bacillus subtilis endospores

The targeting and anchoring of heterologous proteins and peptides to the outer surface of bacteriophages and cells is becoming increasingly important, and has been employed as a tool for fundamental and applied research in microbiology, molecular biology, vaccinology, and biotechnology. Less known are endospores or spores produced by some Gram-positive species. Spores of Bacillus subtilis are surrounded by a spore coat on their outside, and a few proteins have been identified being located on the outside layer and have been successfully used to immobilize antigens and some other proteins and enzymes. The major advantage of spores over the other published systems is their synthesis within the cytoplasm of the bacterial cell. Therefore, any heterologous protein to be anchored on the outside does not have to cross any membrane. Furthermore, spores are extremely resistant against high temperature, irradiation and many chemicals, and can be stored for many years at room temperature.     

Putting endotoxin to work for us: Monophosphoryl lipid A as a safe and effective vaccine adjuvant

The development of non-infectious subunit vaccines greatly increases the safety of prophylactic immunization, but also reinforces the need for a new generation of immunostimulatory adjuvants. Because adverse effects are a paramount concern in prophylactic immunization, few new adjuvants have received approval for use anywhere in the developed world. The vaccine adjuvant monophosphoryl lipid A is a detoxified form of the endotoxin lipopolysaccharide, and is among the first of a new generation of Toll-like receptor agonists likely to be used as vaccine adjuvants on a mass scale in human populations. Much remains to be learned about this compound’s mechanism of action, but recent developments have made clear that it is unlikely to be simply a weak version of lipopolysaccharide. Instead, monophosphoryl lipid A’s structure seems to have fortuitously retained several functions needed for stimulation of adaptive immune responses, while shedding those associated with pro-inflammatory side effects. Received 25 April 2008; received after revision 05 June 2008; accepted 10 June 2008     

Major contribution of codominant CD8 and CD4 T cell epitopes to the human cytomegalovirus-specific T cell repertoire

Human cytomegalovirus (HCMV) infection or reactivation is a cause of morbidity and mortality in immunocompromised individuals. In immunocompetent individuals, in contrast, HCMV is successfully controlled by specific CD8 and CD4 T cells. Knowledge of CD8 and CD4 T cell epitopes from HCMV and their immunodominant features is crucial for the generation of epitope-specific T cells for adoptive immunotherapy and for the development of a peptide-based HCMV vaccine. Therefore, we investigated the natural frequencies of a large number of CD8 and CD4 T cell epitopes, including 10 novel ones. We determined several epitopes as immunodominant. Surprisingly, no clear hierarchies were found for CD8 T cell epitopes, indicating codominance. These results will be valuable for adoptive transfer strategies and support initiatives towards development of a peptide-based HCMV vaccine.Received 12 August 2004; received after revision 24 September 2004; accepted 29 October 2004 These authors contributed equally to this work.     

Synthesis ofO 1.5-(β-D-galactopyranosyl) [DMet2, Hyp5] enkephalin amide,a new highly potent analgesic enkephalin-related glycosyl peptide

Summary A new series of O-glycosyl enkephalins has been prepared, following a convergent strategy, with high chemical yields. The galactosyl analogue,O ^1.5-(-D-galactopyranosyl) [DMet², Hyp⁵] enkephalin amide proved to be one of the most potent in vivo opioid agonists synthesized up to now.     

Malaria vaccine

Summary Among infectious diseases caused by protozoa, malaria is still the greatest killer of children. Mortality in adults living in endemic areas is significantly lower because they frequently acquire partial or complete immunity to the major pathogen,Plasmodium falciparum. This natural protection indicates that vaccination may be possible, and the first candidate antigens were cloned with the use of human immune sera as probes. Genetic and biochemical analysis of the parasite proteins revealed that they are polymorphic, and frequently gene sequences were discovered which were specific for a particular parasite isolate, which eliminated most antigens for purposes of vaccine development. The most promising candidate antigens today are the major surface proteins of sporozoites and blood stage parasites. However, the immune response against those is not sufficient for complete protection, and additional, intensive research is necessary to identify new molecules to be included in a vaccine cocktail against malaria. The current spread of the disease due to increasing drug resistance of parasites and mosquito vectors emphasizes the urgent need for a vaccine.     

Malaria vaccine

Among infectious diseases caused by protozoa, malaria is still the greatest killer of children. Mortality in adults living in endemic areas is significantly lower because they frequently acquire partial or complete immunity to the major pathogen, Plasmodium falciparum. This natural protection indicates that vaccination may be possible, and the first candidate antigens were cloned with the use of human immune sera as probes. Genetic and biochemical analysis of the parasite proteins revealed that they are polymorphic, and frequently gene sequences were discovered which were specific for a particular parasite isolate, which eliminated most antigens for purposes of vaccine development. The most promising candidate antigens today are the major surface proteins of sporozoites and blood stage parasites. However, the immune response against those is not sufficient for complete protection, and additional, intensive research is necessary to identify new molecules to be included in a vaccine cocktail against malaria. The current spread of the disease due to increasing drug resistance of parasites and mosquito vectors emphasizes the urgent need for a vaccine.