氯氰碘柳胺钠通过抑制蛋白酪氨酸磷酸酶SHP2诱导RAS突变型肺癌细胞衰老和死亡

含Src同源2结构域蛋白酪氨酸磷酸酶2(Src homology region 2-containing protein tyrosine phosphatase 2,SHP2)具有调控细胞增殖分化、维持周期、调节免疫等功能,与众多肿瘤的发生发展密切相关. SHP2是RAS蛋白(ratsarcoma protein,RAS)信号通路的重要调控蛋白,研究表明抑制SHP2活性能减缓RAS突变肺癌的进展. 因此筛选特异性的SHP2抑制剂,有助于为肺癌的治疗提供新的手段. 通过建立不同蛋白酪氨酸磷酸酶(protein tyrosine phosphatase,PTP)体外筛选体系,从化合物文库中筛得SHP2特异性抑制剂氯氰碘柳胺钠(closantel sodium,CS),其IC₅₀值为84.83 μmol/L. 采用Western Blot检测CS对SHP2磷酸化的抑制作用;采用细胞热转移试验(cellular thermal shift assay,CETSA)检测在不同温度及浓度下CS对SHP2的热稳定性的影响;采用CCK8检测CS对人肺癌细胞A549、NCI...     

Catalytic reductive dechlorination of p–chlorophenol in water using Ni/Fe nanoscale particles

Nanoscale bimetallic Ni/Fe particles were synthesized from the reaction of sodium borohydride （NaBH4） with reduction of Ni^2＋ and Fe^2＋ in aqueous solution. The obtained Ni/Fe particles were characterized by TEM （transmission electron microscope）, XRD （X-ray diffractometer）, and N2-BET. The dechlorination activity of the Ni/Fe was investigated using p-chlorophenol （p-CP） as a probe agent. Results demonstrated that the nanoscale Ni/Fe could effectively dechlorinate p-CP at relatively low metal to solution ratio of 0.4 g/L （Ni 5 wt%）. The target with initial concentration ofp-CP 0.625 mmol/L was dechlorinted completely in 60 rain under ambient temperature and pressure. Factors affecting dechlorination efficiency, including reaction temperature, pH, Ni loading percentage over Fe, and metal to solution ratio, were investigated. The possible mechanism of dechlorination ofp-CP was proposed and discussed. The pseudo-first- order reaction took place on the surface of the Ni/Fe bimetallic particles, and the activation energy of the dechlorination reaction was determined to be 21.2 kJ/mol at the temperature rang of 287-313 K.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

印刷线路板含氰废水处理工艺实例

氰化物属于剧毒物,含氰废水若不经处理直接排放会严重污染环境.印刷线路板镀金工序会产生含氰废水,对于含氰废水可以根据总氰化物浓度分质处理,也可以采用组合工艺处理.江苏省某印刷线路板生产企业采用"电解+离子交换+纤维吸附"工艺处理含氰废水,处理后,企业委托监测公司对废水水质进行了监测,根据监测结果,废水中总氰化物浓度能够达...     

饮用水中氯消毒的应用及存在的主要问题

氯消毒在饮用水净化过程中被广泛采用,我国99.5%以上的水厂用氯消毒,在美国也有94.5%的自来水厂用氯消毒。氯消毒一般采用预加氯和后加氯两种方式。氯在消毒的同时会产生三卤甲烷、二氯乙酸等消毒副产物。这些消毒副产物有致癌、致畸、致突变性和遗传毒性,对人体的健康存在一定的危害性。在氯消毒过程中,余氯量越多产生的消毒副产物就越多,而余氯量过少对病毒的灭活性较差,同时在输水管中细菌就会大量繁殖,加快管道的腐蚀。不同浓度的余氯排入水体还会对鱼类和水生生物造成不同程度的毒性影响。     

水中典型含氮有机物氯化生成消毒副产物的潜能研究

选取了受污染原水中广泛存在的12种含氮有机物（除草剂、杀虫剂、氨基酸、工业品等）,开展了氯化和氯胺化培养生成典型消毒副产物的实验,目的是通过对水中脲类除草剂、嗪类除草剂和其他含氮化合物培养生成不同消毒副产物的生成量,讨论不同种类含氮化合物生成含碳和含氮消毒副产物规律以及考察不同消毒副产物的可能前体物.研究发现,脲类除草...     

Pd/TiO2对水体中2,4-二氯酚的催化加氢脱氯研究

分别采用沉淀-沉积法和浸渍法合成了Pd/TiO2催化剂,采用透射电镜(TEM)、X射线衍射(XRD)和电感耦合等离子体发射光谱(ICP-AES)对材料进行了表征,并对2,4-二氯酚的催化加氢脱氯反应进行了研究.结果表明,2种方法制备的催化剂在加氢脱氯反应中均具有较好的效果,沉淀-沉积法制备的催化剂活性更高,当反应物初始浓度为3.11 mmol.L-1,pH为12,催化剂用量为50 mg时,45 min内2,4-二氯酚可以完成脱氯过程.酸性条件有利于反应的进行.当催化剂用量在15～80 mg时,反应初活性没有明显变化,因此催化反应过程不受传质阻力的影响.当反应物初始浓度在0.62～3.11 mmol.L-1时反应初活性随浓度的提高显著增加,但进一步增加反应物的浓度时初活性没有明显提高,因此2,4-二氯酚在催化剂上的加氢脱氯行为符合Langmuir-Hinshelwood模型,表明2,4-二氯酚的加氢脱氯受表面吸附所控制.     

自制固氯剂对垃圾衍生燃料(RDF)的固氯效果分析

在粉碎后的垃圾中分别添加5%的CaO、Ca(OH)2、ZYgl作为固氯剂,研究了RDF成型率、落下强度、热值、着火性能及固氯效果。研究表明:三种添加剂均有利于RDF成型,成型率和落下强度均以ZYgl最高,分别为90%和81.8%;三种RDF热值均在14229kJ/kg左右,高于原垃圾的10881kJ/kg,燃料的着火性能降低了25%。添加5%CaO、Ca(OH)2、ZYgl制备成的RDF在800℃下焚烧2h后,N元素100%挥发,但S、Cl元素的挥发率大幅度降低,尤其以添加5%的ZYgl效果显著,S、Cl元素在800℃下的挥发率分别降为53.33%和15.91%。     

三种氯代酚的水生态毒理和水质基准

氯酚化合物主要包括2,4-二氯酚、2,4,6-三氯酚和五氯酚等, 是一类重要的化工产品, 在环境中分布广泛. 氯酚在水体中的生态毒理行为一直是人们关注的焦点. 本文概述了2,4-二氯酚、2,4,6-三氯酚和五氯酚在水环境中的迁移归趋, 在水生生物体内的吸收代谢及其生态毒性和毒理特性. 在此基础上, 对3种氯代酚的水生态基准进行推导讨论, 以期为氯酚类污染物的环境管理、安全评价和污染防治提供基础资料.     

测定水中氰化物影响条件的实验研究

异烟酸—吡唑啉酮分光光度法在实际应用中稳定性较差,通过对显色反应条件的试验,以及对其他影响因素的分析,探索测定了反应的最佳条件。