未来10大高风险高回报的新技术

世界经济论坛全球事务理事会发布了一份关于信息技术的新报告,其中提到了10项有可能对全社会造成重大影响的新技术。这10项新技术涵盖了科学、医学、能源、制造、交通和电子等众多领域,理事会的报告简要说明了那些新技术将如何影响和改变我们的生活。     

碳酸钙中的碳能被微藻利用吗

碳酸钙中的碳能否被微藻利用这一问题一直处于争论中。本文在开放与隔离空气CO2环境下用含有碳酸钙粉末和不同浓度乙酰唑胺的培养液培养衣藻和小球藻。通过双向同位素示踪技术,定量描述出不同条件下微藻对碳酸钙碳源的利用份额。在隔离空气CO2的环境下,微藻对碳酸钙碳源的利用份额明显大于开放环境下。在开放环境下,随着培养液中乙酰唑胺浓度增加,生物量减少,微藻对固有无机碳源的利用份额减少,对碳酸钙碳源的利用份额增加。在隔离空气CO2的环境下,随着培养液中乙酰唑胺浓度增加,微藻生物量增加,衣藻对固有无机碳源的利用份额增加,对碳酸钙碳源的利用份额减少,而小球藻反之。微藻主要是通过利用碳酸钙溶蚀的可溶性无机碳(DIC)这种间接方式来利用碳酸钙碳源。而外界大气CO2浓度和胞外碳酸酐酶是影响碳酸钙溶解的重要因素,因此其也明显的影响着微藻对碳酸钙碳源的利用。     

胞外碳酸酐酶对湖泊微藻稳定碳同位素组成的影响

本文以红枫湖、百花湖和阿哈水库中的微藻为研究对象,通过测定湖水中的DIC含量,微藻胞外碳酸酐酶活力和藻体的稳定碳同位素组成等信息,来研究湖泊微藻的碳同位素组成对全球气候变化的响应。结果发现:水体无机碳和微藻胞外碳酸酐酶活力是影响湖泊微藻稳定碳同位素组成变化的决定性因素。本研究所获得的认识将在全球气候变化方面具有重要意义。     

一株苯酚降解菌的分离鉴定及响应面法优化其固定化

从太原市焦化厂废水活性污泥中分离、筛选出一株苯酚降解细菌,经生理生化反应和16S rRNA鉴定,该菌株为Diaphorobacter属细菌,命名为PD-07.代谢机制研究表明,苯酚可诱导该菌合成邻苯二酚2,3-加氧酶降解苯酚.为了提高该菌株对苯酚的降解率,以海藻酸钙为材料,对该菌株进行包埋固定化研究.首先采用Plackett–Burman实验设计筛选出影响固定化菌株苯酚降解率的关键因素,然后采用最陡爬坡实验逼近最大苯酚降解率响应区域.最后用Box–Behnken实验设计及响应面回归分析,应用二次方程对实验数据进行拟合得,拟合曲线与实验实测值相关性良好,最佳条件为海藻酸钠浓度3.83%(m/V)、CaCl20.3mol/L、菌胶比1:26.73、固定化时间2h、摇床转速180r/min、培养温度30℃、初始pH值7.2、液固比4.86:1,在此条件下苯酚降解率可达96.89%.     

Mutagenic and cytotoxic potential of Endosulfan and Lambda-cyhalothrin - In vitro study describing individual and combined effects of pesticides

Excessive use of pesticides poses increased risks to non target species including humans. In the developing countries, lack of proper awareness about the toxic potential of pesticides makes the farmer more vulnerable to pesticide linked toxicities, which could lead to diverse pathological conditions. The toxic potential of a pesticide could be determined by their ability to induce genetic mutations and cytotoxicity. Hence, determination of genetic mutation and cytotoxicity of each pesticide is unavoidable to legislate health and safety appraisal about pesticides. The objective of current investigation was to determine the genotoxic and cytotoxic potential of Endosulfan（EN） and Lambda-cyhalothrin（LC）; individually and in combination. 3-（4,5-Dimethylthiazol-2-yl）-2,5-Diphenyltetrazolium Bromide（MTT） assay was utilized to determine cytotoxicity, while two mutant histidine dependent Salmonella strains（TA98, TA100） were used to determine the mutagenicity of EN and LC.Moreover, mutagenicity assay was conducted with and without S9 to evaluate the effects of metabolic activation on mutagenicity. Even though a dose dependent increase in the number of revertant colonies was detected with EN against both bacterial strains, a highly significant（p 〈 0.05） increase in the mutagenicity was detected in TA98 with S9. In comparison, data obtained from LC revealed less mutagenic potential than EN. Surprisingly,the non-mutagenic individual-concentrations of EN and LC showed dose dependent mutagenicity when combined. Combination of EN and LC synergistically induced mutagenicity both in TA98 and TA100. MTT assay spotlighted comparable dose dependent cytotoxicity effects of both pesticides. Interestingly, the combination of EN and LC produced increased reversion and cytotoxicity at lower doses as compared to each pesticide, concluding that pesticide exposure even at sub-lethal doses can produce cytotoxicity and genetic mutations, which could lead to carcinogenicity.     

Primary neuronal-astrocytic co-culture platform for neurotoxicity assessment of di-(2-ethylhexyl) phthalate

Plastics such as polyvinyl chlorides （PVC） are widely used in many indoor constructed environments; however, their unbound chemicals, such as di-（2-ethylhexyl） phthalates （DEHP）, can leach into the surrounding environment. This study focused on DEHP＇s effect on the central nervous system by determining the precise DEHP content in mice brain tissue after exposure to the chemical, to evaluate the specific exposure range. Primary neuronal-astrocyte co-culture systems were used as in vitro models for chemical hazard identification of DEHP. Oxidative stress was hypothesized as a probable mechanism involved, and therefore the total reactive oxygen species （ROS） concentration was determined as a biomarker of oxidative stress. In addition, NeuriteTracer, a neurite tracing plugin with ImageJ, was used to develop an assay for neurotoxicity to provide quantitative measurements of neurological parameters, such as neuronal number, neuron count and neurite length, all of which could indicate neurotoxic effects. The results showed that with 1 nmol/L DEHP exposure, there was a significant increase in ROS concentrations, indicating that the neuronal-astrocyte cultures were injured due to exposure to DEHP. In response, astrocyte proliferation （gliosis） was initiated, serving as a mechanism to maintain a homeostatic environment for neurons and protect neurons from toxic chemicals. There is a need to assess the cumulative effects of DEHP in animals to evaluate the possible uotake and effects on the human neuronal system from exoosure to DEHP in the indoor environment.     

Characterization of extracellular polymeric substances in the biofilms of typical bacteria by the sulfur K-edge XANES spectroscopy

A combined approach of physicochemical extraction and sulfur K-edge X-ray absorption near-edge structure（XANES） spectroscopy was applied to characterize the extracellular polymeric substances（EPS） of typical bacterial biofilms in this study. Physicochemical analysis showed variation of the contents of DNA,polysaccharide and protein in different fractions of EPS in different mediums. The sulfur K-edge XANES analysis yielded a variety of spectra.Spectral fitting of the XANES spectra utilizing a large set of model compounds showed that there was more reduced sulfur in both LB-EPS（loosely bound EPS） and TB-EPS（tightly bound EPS） of all the biofilms in LB medium than in R2 A medium. More oxidized sulfur was identified in LB-EPS than that in TB-EPS,suggesting different niches and physiological heterogeneity in the biofilms. Our results suggested that the sulfur K-edge XANES can be a useful tool to analyze the sulfur speciation in EPS of biofilms.     

检测细胞DNA断裂损伤效应的彗星实验法的改良

为了解决彗星实验过程中常出现的脱胶、细胞核分离操作繁琐、重复性低等问题,对彗星实验方法进行了改良,初步建立了彗星实验的快速操作流程。结果显示,通过对载玻片进行预处理,可确保凝胶悬挂均匀;采用改良机械法分离的细胞核浓度适中;以0.5%(w/v)涂层琼脂糖作为基层、以1.5%(w/v)低熔点包埋琼脂糖作为叠加层的"双层凝胶法",辅以"推片法"铺胶,操作便捷且不发生脱胶现象;细胞核膜经裂解处理后再进行电泳和荧光观察,彗星图像清晰,杂质少。应用改良后的彗星实验方法,操作简便,耗时更短,实验效果良好,可快速检测出细胞DNA损伤效应。     

蛋白质精氨酸甲基转移酶抑制剂DB75对人膀胱癌T24细胞的抑制作用

蛋白质精氨酸甲基转移酶1(PRMT1)是近年来新发现的一种表观遗传修饰酶,在膀胱癌等多种癌组织中过度表达,因此针对该靶点的新型表观抗肿瘤药物研究尤为重要.通过基于PRMT1药效团虚拟筛选模型筛查抑制PRMT1活性的小分子化合物,体外研究了靶向PRMT1的小分子化合物DB75对膀胱癌细胞的抗瘤活性及诱导细胞凋亡的分子机制.实验结果显示:通过筛选体系获得了能显著抑制PRMT1活性的小分子化合物DB75;MTT实验表明,DB75能够显著(P<0.05)地抑制膀胱癌T24细胞的增殖,且随着药物浓度的增加,抑制率呈明显的剂量效应,48 h半数抑制浓度IC50为2.2μmol/L;DAPI染色显示DB75能显著(P<0.05)诱导膀胱癌T24细胞凋亡;分子机制研究显示,DB75通过激活Caspase-3和PARP活性从而诱导T24细胞凋亡.以上结果初步表明DB75可作为一种新型的膀胱癌表观先导化合物.     

茚虫威对斑马鱼的急性毒性及遗传毒性

茚虫威属噁二嗪类新型广谱高效杀虫剂,在农业生产中有着重要作用,近年来随着用量的增加,由此产生的对水生生物的影响越来越受到重视。使用斑马鱼进行茚虫威的急性毒性作用实验,并采用微核试验、彗星试验、Annexin V-FITC/PI双染色检测观察染毒后的斑马鱼是否被诱导产生遗传毒性。结果表明:在24 h、48 h、72 h、96 h,茚虫威LC50值分别为2.263mg·L-1、2.184 mg·L-1、2.184 mg·L-1、2.133 mg·L-1。茚虫威对斑马鱼急性毒性属中等毒性。96 h茚虫威浓度为1.98 mg·L-1和2.16 mg·L-1时,斑马鱼的微核率与对照组相比达差异极显著水平(P0.01)。采用彗星试验检测斑马鱼肝脏DNA损伤,结果显示斑马鱼暴露于高浓度1.98 mg·L-1和2.16 mg·L-1茚虫威后,与对照组相比,斑马鱼的DNA损伤均表现为极显著差异(P0.01)。采用Annexin V-FITC/PI双染色流式细胞仪法检测,结果表明染毒后24 h斑马鱼肝细胞出现细胞凋亡现象。实验结果进一步表明,茚虫威对斑马鱼短期染毒后诱导细胞凋亡,表现出遗传毒性。