石墨烯及其衍生物在肿瘤诊疗方面的应用

功能化石墨烯及其衍生物具有独特的物理化学性质,在很多领域备受关注。其中,在生物医学领域已成为研究热点,尤其在恶性肿瘤的早期诊断与治疗方面具有独特的优越性。本研究就近几年来石墨烯及其衍生物在肿瘤诊断及其在抗肿瘤作用中的相关研究作一简要综述,为恶性肿瘤的诊断与治疗提供新的视角,为石墨烯临床应用提供一定的理论依据。     

石墨烯及其衍生物氧化石墨烯作为新型药物载体材料在肿瘤治疗领域的应用研究

石墨烯及其衍生物氧化石墨烯因具有水溶性好、比表面积大、载药量高以及易于修饰等优势,近年来在生物医药领域尤其在肿瘤治 疗领域的应用研究发展迅速。综述石墨烯及氧化石墨烯作为新型药物载体材料所具有的特性和生物安全性、表面修饰方式以及在肿瘤靶向 递药系统中的应用,为其在生物医药领域的应用研究提供新方法和新思路。     

基于石墨烯及其相关材料高分析性能传感器研究进展

基于石墨烯优异的导电性能、大的比表面积、良好的生物相容性,在传感器的构建方面,表现出比其他材料更加优良的性能。石墨烯在传感领域中的应用一般通过功能化来实现,石墨烯与聚合物或纳米粒子的结合可以显著增强传感器的响应,提高检测的灵敏性。综述了近年来石墨烯及其相关材料在临床分析、环境监测和食品安全控制等传感领域中的应用研究进展,通过灵敏度、检测限等分析数据对具有良好水分散性和生物相容性,比表面大,表面修饰灵活以及制备简单的氧化石墨烯及其衍生物(含氧基团)为基础的传感器的分析性能进行了综合评价。同时对石墨烯及其衍生物这一新型传感材料在未来的研究趋势进行了展望:精确控制石墨烯单分散片的尺寸、形状;研究催化作用下的石墨烯与分析物分子电极反应间的传感机制;减少石墨烯片的聚集,精确控制石墨烯基传感系统微结构。未来可望发展具有更加强大特性的便携式、芯片化传感器,实现更短时间内复杂环境样品的多重分析,进一步提高检测灵敏性和选择性,增强传感器的稳定性和重复使用性,克服毒性和生物不容性。     

氧化石墨烯荧光性能在生物医学领域的应用

石墨烯(graphene)作为一种新兴产物在生物医学领域的应用越来越广泛,氧化石墨烯(graphene oxide,GO)作为石墨烯的重要衍生物之一,得益于其异源的电学结构,因而在一定波长范围内可以产生荧光。正是这一性能使得GO在生物医学领域有着巨大的潜力,主要介绍了近年来GO的荧光性能在分子检测、疾病诊断、细胞成像等方面的应用,并展望了其发展前景。     

石墨烯的环境行为及其对环境中污染物迁移归趋的影响

石墨烯是当前研究最热的碳纳米材料,具有独特的理化特性,在各领域具有广阔的应用前景.随着其生产和使用量的不断增大,石墨烯不可避免地会进入到环境中,从而给生态环境和人类健康带来风险.深入理解石墨烯在环境中的行为和归趋,探讨石墨烯对污染物环境行为的影响,对于科学客观评价石墨烯的环境风险具有十分重要的意义.本文对石墨烯的环境行为及其对污染物迁移归趋的影响进行了综述,主要介绍了石墨烯在水环境中的胶体特性和稳定性,以及在多孔介质中的迁移,重点探讨了石墨烯与重金属和有机物之间的相互作用,并从吸附机理、石墨烯与土壤组分之间的相互作用、石墨烯对污染物在环境中迁移及生物有效性的影响、石墨烯的定量方法等方面对该研究领域的前景和重点进行了展望,以期为该领域的深入研究提供借鉴并拓展新的思路.     

木质素及其衍生物在提取冶金中的研究进展

在介绍木质素的结构、来源、提取方法及其改性的基础上,对木质素及其衍生物在提取冶金中的应用进行综述。总结了木质素及其衍生物在去除废水中一些重金属离子(Pb~(2+)、Cu~(2+)和Cr~(3+)等)、回收溶液中有价金属离子及选择性分离特定金属离子的应用效果,并指出现阶段木质素及其衍生物在提取冶金中存在的问题,特别是对吸附机理、解吸机理及解吸行为的研究不够系统深入,最后展望了木质素及其衍生物在提取冶金中的应用。     

美国NOVA出版社最新书刊介绍华南师范大学郭周义教授研究成果

石墨烯（Graphene）是已知的世上最薄、最坚硬的纳米材料，它是一种由碳原子构成的单层片状结构的新材料。2004年，英国曼彻斯特大学物理学家安德烈·海姆（AndreGeim）和康斯坦丁·诺沃肖洛夫（Konstantin Novoselov）成功地在实验中从石墨巾分离出石墨烯，而证实它可以单独存在，两人也因“在二维石墨烯材料的开创性实验”，共同获得2010年度诺贝尔物理学奖。近期，美国NOVA出版社出版了关于石墨烯的最新专著：《Graphene Oxide：Synthesis，Mechanical Properties and Applications》。该书介绍了氧化石墨烯及其衍生物在合成、物理化学性质，以及在生物医学、电磁屏蔽材料利能源、环保等研究领域中的最近进展。     

氨基酸环状衍生物的合成及抑菌活性

近年来,氨基酸及其衍生物在医药和农业上已显示有广阔的应用前景。现就近十余年来,国外文献报道的具有抗病原微生物活性的氨基酸环状衍生物作一简要概述。     

壳聚糖及其衍生物作为药物载体研究进展

壳聚糖是甲壳素脱乙酰化的衍生物,是自然界中唯一的碱性多糖.壳聚糖及其衍生物是一类资源丰富、可生物降解的天然聚合物,具有生物相容性、高电荷密度、无毒性和粘膜粘附性,广泛应用于生物医学和药物制剂领域.壳聚糖作为药物载体可以控制药物释放、提高药物疗效、降低药物毒副作用,可以提高疏水性药物对细胞膜的通透性和药物稳定性及改变给药途径,还可以加强制刑的靶向给药能力.本文分别从壳聚糖及其衍生物在大分子药物载体、缓控释系统及不同部位给药系统中的应用进行了综述,以说明壳聚糖及其衍生物是一种优良的药物传递载体和新型药用辅料.     

壳聚糖及其衍生物抗肿瘤作用研究进展

壳聚糖为天然多糖甲壳素脱除部分乙酰基的产物,是自然界存在的唯一碱性多糖,无毒,可生物降解,具有免疫功能和良好的生物相容性。近年发现,壳聚糖具有抗肿瘤作用,却因其难溶于水及中性溶剂而影响其应用,壳聚糖衍生物改善了壳聚糖的这个缺点,也具有更广泛的药理作用。本文对壳聚糖及其壳聚糖衍生物在抗肿瘤方面的研究情况做了综述。     

A Unique Protease Cleavage Site Predicted in the Spike Protein of the Novel Pneumonia Coronavirus (2019-nCoV) Potentially Related to Viral Transmissibility

正Dear Editor,In December 2019, a novel human coronavirus caused an epidemic of severe pneumonia(Coronavirus Disease 2019,COVID-19) in Wuhan, Hubei, China(Wu et al. 2020; Zhu et al. 2020). So far, this virus has spread to all areas of China and even to other countries. The epidemic has caused 67,102 confirmed infections with 1526 fatal cases     

Curcuminoids as inhibitors of thioredoxin reductase: A receptor based pharmacophore study with distance mapping of the active site

Curcumin is the yellow pigment of turmeric that interacts irreversibly forming an adduct with thioredoxin reductase (TrxR), an enzyme responsible for redox control of cell and defence against oxidative stress. Docking at both the active sites of TrxR was performed to compare the potency of three naturally occurring curcuminoids, namely curcumin, demethoxy curcumin and bis-demethoxy curcumin. Results show that active sites of TrxR occur at the junction of E and F chains. Volume and area of both cavities is predicted. It has been concluded by distance mapping of the most active conformations that Se atom of catalytic residue SeCYS498, is at a distance of 3.56 from C13 of demethoxy curcumin at the E chain active site, whereas C13 carbon atom forms adduct with Se atom of SeCys 498. We report that at least one methoxy group in curcuminoids is necessary for interation with catalytic residues of thioredoxin. Pharmacophore of both active sites of the TrxR receptor for curcumin and demethoxy curcumin molecules has been drawn and proposed for design and synthesis of most probable potent antiproliferative synthetic drugs.     

Comparative morphology of the carpel in the Liliaceae: Hewardieae, Petrosavieae, and Tricyrteae

The young pistils in the melanthioid tribes, Hewardieae, Petrosavieae and Tricyrteae, are uniformly tricarpellate and syncarpous. They lack raphide idioblasts. All are multiovulate, with bitegmic ovules. The Petrosavieae are marked by the presence of septal glands and incomplete syncarpy. Tepals and stamens adhere to the ovary in the Hewardieae and the Petrosavieae but not in the Tricyrteae. Two vascular bundles occur in the stamens of the Hewartlieae and Tricyrtis latifolia. Ventral bundles in the upper part of the ovary of the Hewardieae are continuous with compound septal bundles and placental bundles in the lower part. Putative ventral bundles occur in the alternate position in the Tricyrteae and putative placental bundles in the opposite. position in the Petrosavieae. The dichtomously branched stigma in each carpel of the Tricyrteae is supplied by a bifurcated dorsal bundle.     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.     

Perinatal Vertical Transmission of Chikungunya Virus in Ruili,a Town on the Border between China and Myanmar

正Dear Editor,Chikungunya virus (CHIKV), an arbovirus in the family of Togaviridae, genus Alphavirus, is transmitted by the A.aegyptii or A. albopictus mosquito, and causes disease in humans characterized by fever, rash, and arthralgia (Silva and Dermody 2017; Suhrbier 2019). It was first reported in 1953 in Tanzania, and caused only a few outbreaks and sporadic cases in Africa and Asia in last century. However, in the epidemic in 2004, CHIKV acquired mutations that conferred enhanced transmission by the A. albopictus mosquito(Schuffenecker et al. 2006). Since then, it has successively caused outbreaks in Africa, the Indian Ocean, South East Asia, the South America, and Europe (Zeller et al. 2016).