氨基酸schiff碱及其金属配合物的性能研究进展

氨基酸Sch iff碱及其金属配合物具有良好的抗炎、抗菌、抗癌等生物活性而有望成为高效、低毒、可供临床使用的新药物而引起人们的极大关注。本文综述了氨基酸sch iff碱及其金属配合物的生物活性、测定金属含量、催化、载氧等性能的研究情况(特别是在生物活性方面),并分析总结了其在研究方面存在的问题。     

Mutagenicity of the carcinogen 7-bromomethylbenz (a)-anthracene: a quantitative study in repair-deficient strains of Escherichia coli

The mutagenicity of 7-bromomethylbenz[a]anthracene, a reactive arylalkylating carcinogen, was investigated in several strains of E. coli WP2, using reversion from tryptophan auxotrophy (ochre trpE locus) as a measure of induced mutation.WP2, the wild-type with respect to DNA repair, was more resistant to the cytotoxic effects of 7-bromomethylbenz[a]anthracene than WP2uvrA, WP2exrA, or WP2uvrAexrA, the D₃₇ doses of carcinogen being 22, 5, 8, and 1 μg/ml respectively. Mutagenesis in WP2 was observed only at doses in excess of the D_Q, whereas in WP2uvrA mutation was linearly related to dose throughout the range studies. No mutation was detectable in WP2exrA or WP2uvrAexrA even at doses which resulted in 95% and 99.9% lethality respectively. It was concluded that an intact Exr function was an absolute requirement for the induction of mutation by 7-bromomethylbenz[a]anthracene and that excision-repair was very efficient in removing premutational lesios.The use of $\text{[}{}^3\text{H}\text{]7-}\text{bromomethylbenz}\text{[a]}\text{anthracene}$ at high specific radioactivity enabled the quantitation of mutation as a function of the extent of reaction of the mutagen with cellular macromolecules. Extent of reaction with DNA, RNA and protein was linearly related to dose, binding to DNA being 3 times that to RNA and 20 times that to protein. There was a linear relationship between binding and mutation in WP2uvrA and the effective target size for Exr-mediated mutation in this system was of the order of 0.04 nucleotides. Having established that the n umber of 7-bromomethylbenz[a]anthracene-induced mutants increased linearly with successive cell generations and, by use of T4 ochre427, that about 30% of the mutants scored were true revertants, it was estimated that the Exr pathway incorporates productive errors into the bacterial genome with a frequency of the order of 2.10^?3.     

Sustainable development at the village level in Bali,Indonesia

Using a stress-capability framework, the problems and opportunities for sustainable development at the village level in Bali are examined. Balinese culture incorporates a traditional form of local government which emphasizes cooperation, consensus building, and balance. These aspects provide a strong foundation for sustainable development initiatives. At the same time, many decisions are being taken external to the villages, and even to Bali, which may lead to problems for development initiatives.     

STANDARD CIRCUMSTANCES AND VITAL GOALS: COMMENTS ON VENKATAPURAM'S CRITIQUE

This article is a reply to Venkatapuram's critique in his article Health, Vital Goals, Capabilities, this volume. I take issue mainly with three critical points put forward by Venkatapuram with regard to my theory of health. (1) I deny that the contents of my vital goals are relative to each community or context, as Venkatapuram claims. There is no conceptual connection at all between standard circumstances and vital goals, as I understand these concepts. (2) Venkatapuram notes that I stop short of filling the framework of vital goals with any content and thereby make my concept of health less concrete. I reply that some vital goals are indeed universal, viz. the ones which are necessary conditions for survival. Many other vital goals are individual and cannot therefore be included in a universal list. (3) Venkatapuram claims that my definition of vital goals is too broad, since it entails that some persons without any disease can be regarded as ill. However, in my understanding health is a relational concept from a state of complete health to a state of maximal illness. In this framework, a minor reduction of a state of complete health does not entail illness. This article also contains a comparison between my theory of health and Martha Nussbaum's theory of capabilities for dignity.     

疫情下“基因工程”课程线上跨学科教学模式设计与实践

"新冠"疫情暴发凸显基因工程技术对社会经济的重大影响,基因工程离我们的生活越来越近。"新冠"疫情下,为了让学生更好地完成"基因工程"课程的居家学习,我们采用了基础知识微课自学(Small Private Online Course,SPOC)+案例应用课堂剖析(Tencent Instant Messenger,QQ)+管理拓展课后互助(QQ群)+疑难问题实时解答(QQ群)的跨学科教学模式开展在线教学,通过问题引入、真实情景剖析、跨学科拓展完成了课程基本原理和主要方法的教学,使学生掌握了基因研究的基本方法、基因表达流程、基因技术应用及安全管理相关的知识。通过思考新型冠状病毒肆虐情境下如何防控,帮助学生明晰了学习目的,提高了跨学科学习的兴趣;通过新型冠状病毒核酸检测的真实情景问题和组织实施由目标设计过程、确定方法、学习课程知识,进而掌握不同学科知识应用技能的跨学科教学活动,提高了学生将基因操作技能与专业技能融合解决实际问题的能力。教学实践证明,基础自学+案例剖析+互助拓展+实时答疑的跨学科在线教学模式,可以顺利完成课程教学任务并获得与传统课堂教学等同的效果;分析案例识别问题→设计方案解析...     

Flash Converted Graphene for Ultra‐High Power Supercapacitors

Supercapacitors are known for their rapid energy charge–discharge properties, often ten to a hundred times faster than batteries. However, there is still a demand for supercapacitors with even faster charge–discharge characteristics to fulfill the requirements of emerging technologies. The power and rate capabilities of supercapacitors are highly dependent on the morphology of their electrode materials. An electrically conductive 3D porous structure possessing a high surface area for ions to access is ideal. Using a flash of light, a method to produce highly interconnected 3D graphene architectures with high surface area and good conductivity is developed. The flash converted graphene is synthesized by reducing freeze‐dried graphene oxide using an ordinary camera flash as a photothermal source. The flash converted graphene is used in coin cell supercapacitors to investigate its electrode materials properties. The electrodes are fabricated using either a precoating flash conversion or a postcoating flash conversion of graphene oxide. Both techniques produce supercapacitors possessing ultra‐high power (5–7 × 10⁵ W kg^?1). Furthermore, optimized supercapacitors retain >50% of their capacitance when operated at an ultrahigh current density up to 220 A g^?1.     

Analysis of Amblyomma sculptum haplotypes in an area endemic for Brazilian spotted fever

Amblyomma sculptum (Ixodida: Ixodidae) Berlese, 1888, a member of the Amblyomma cajennense complex, is the major vector of Brazilian spotted fever (BSF) in southeastern Brazil. In this study, the genetic diversity of A. sculptum populations in the state of Rio de Janeiro (RJ), Brazil, was investigated because genetic variability in tick populations may be related to vector competence. Samples of A. sculptum from 19 municipalities in 7 regions of RJ were subjected to DNA extraction, amplification and sequencing of D‐loop, cytochrome oxidase II and 12S rDNA mitochondrial genes. These sequences were used to map the genetic diversity of this tick. Amblyomma sculptum populations are genetically diverse in RJ, especially in the South Centre and Highland regions. Few unique haplotypes were observed in all populations, and the majority of genetic variation found was among ticks within each population. Phylogenetic reconstruction reinforced the assumption that all the haplotypes identified in RJ belong to A. sculptum. However, some RJ haplotypes are closer to A. sculptum from Argentina than to A. sculptum from elsewhere in Brazil. In RJ, A. sculptum has high genetic diversity, although little genetic differentiation. Observations also indicated a high level of gene flow among the studied populations and no evidence of population structure according to region in RJ.