A review on the synthesis of transition metal nitride nanostructures and their energy related applications

Transition metal nitrides(TMN)have recently grabbed immensely appealing as ideal active materials in energy storage and catalysis fields on account of their remarkable electrical conductivity,excellent chemical stability,wide band gap and tunable morphology.Both pure TMN and TMN-based materials have been extensively studied concerned with their preparation approaches,nanostructures,and favored performance in various applications.However,the processes towards synthesis of TMN are numerous and complex.Choosing appropriate method to obtain target TMN with desired structure is crucial,which further affects its practical application performance.Herein,this review offers a timely and comprehensive summary of the synthetic ways to TMN and their application in energy related domains.The synthesis section is categorized into in-situ and ex-situ based on where the N element in TMN origins from.Then,overviews on the energy related applications including energy storage,electrocatalysis and photocatalysis are discussed.In the end,the problems to be solved and the development trend of the synthesis and application of transition metal nitrides are prospected.

Investigation of transcriptional gene silencing and mechanism induced by shRNAs targeted to RUNX3 in vitro

AIM:To investigate transcriptional gene silencing induced by short hairpin RNAs (shRNAs) that target gene prompter regions of RUNX3 gene, and whether shRNAs homologous to DNA sequences may serve as initiators for methylation. METHODS:According to the principle of RNAi design, pSilencer3.1-H1-shRNA/RUNX3 expression vector was constructed, The recombinant plasmid shRNA was transfected into human stomach carcinoma cell line SGC7901 with Lipofectamine 2000. Then, the positive cell clones were screened by G418. The mRNA and protein expression level of RUNX3 in the stable transfected cell line SGC7901 were determined by RT-PCR, Western blotting and immunocytochemistry. Characteristics of the cell lines including SGC7901, pSilencer3.1-H1/SGC7901 and pSilencer3.1-H1-shRNA/RUNX3/SGC7901 were analyzed with growth curves, clone formation rate and cell-cycle distribution. The activated level of RUNX3 was examined after treatment with the different density of 5’-aza-2’-deoxycytidine (5-Aza-CdR) by using semi- quantitative RT-PCR and Western blotting. RESULTS:In the cell line SGC7901 transfected with pSilencer3.1-H1-shRNA/RUNX3, mRNA and proteinexpression of the RUNX3 gene was lost identified by RT- PCR, Western blotting and immunocytochemistry assay. The growth of pSilencer3.1-H1-shRNA/ RUNX3/SGC7901 cells without expression of RUNX3 was the fastest (P < 0.05), its rate of clone formation was the highest (P < 0.01), and the cell distribution in G0/G1 and S/M phases was lowest and highest, respectively (P < 0.05), compared with that of the transfected pSilencer3.1-H1 and non-transfected cells. Through RT-PCR and Western blot assay, inactivated RUNX3 could not be reactivated by 5-Aza-CdR. CONCLUSION:We found that, although shRNAs targeted to gene prompter regions of RUNX3 could effectively induce transcriptional repression with chromatic changes characteristic of inaction promoters, this was independent of DNA methylation, and the presence of RNA-dependent transcriptional silencing showed that RNA-directed DNA methylation might be an existing gene regulatory mechanism relative to the methylated in humans.

浅谈客滚船简化撤离分析

简要描述了客滚船简化撤离分析的计算流程与步骤。

Spatio-Temporal Variability of Shallow Groundwater Quality in a Hilly Red-Soil Agricultural Catchment in Subtropical Central China

Groundwater quality varies not only in space but also in time. In order to analyze the spatiotemporal variety of ground water quality, the concentration of ammonium nitrogen (NH4N), nitrate nitrogen (NO3N), total nitrogen (TN) and total phosphorus (TP) in very shallow groundwater were investigated in a red-soil catchment in subtropical central China, based on a three-dimensional kriging method. The spatio-temporal analysis demonstrated that NH4N, NO3N and TP presented strong spatio-temporal autocorrelation (with a nugget-to-sill ratio of <25%) and that TN presented a moderate spatio-temporal autocorrelation (with a nugget-to-sill ratio between 25% and 75%). According to the Chinese Groundwater Quality Standards, the ratio of areas contaminated by NH4N, NO3N, TN and TP to the whole catchment was 20.05%, 1.46%, 5.07%, 5.98%, respectively. The 3D delineation of continuously dynamic variation of contaminated area indicated that the catchment’s very shallow groundwater had a moderate contamination by NH4N, slight by TN and TP, and almost non by NO3N. Although the contaminated area was very small, only occurring in small dispersed patches, a close attention should be paid to the shallow groundwater quality because local farmers obtain their domestic drinking water directly from this shallow groundwater without any treatment prior to consuming and the potential health hazard is considerable. The findings from this study highlight the importance of surveillance of the contaminated area over time for decision making to protect public health and maintain sustainable development of the catchment.

基于蒽和三苯胺基D-π-A结构的蓝色荧光材料在有机发光和紫外探测集成器件中的应用

有机集成化光电子器件兼具了小型化和多功能性的优势,如集成了有机发光和紫外探测的有机发光紫外探测器件(OLED-UVOPDs).这种器件中的有机光电材料的设计仍然面临重大的挑战.在本文中,以蒽为π桥,腈基苯为受体,三苯胺(TPA)和二甲基三苯胺(2mTPA)分别为给体,设计并合成了两种可用于OLED-UVOPD器件的蓝色发光分子,TPA-AN和2mTPA-AN.它们的发光峰分别位于474和488 nm处,荧光量子产率为51.1%和46.6%.通过单载流子器件计算得到其电子迁移率分别为3.96×10^(-5)和6.63×10^(-7)cm^(2)V^(-1)s^(-1).基于TPA-AN的OLED器件表现出强的蓝光发射,最大亮度为43,110 cd m^(-2),最大外量子效率(EQE)为8.1%.它们在OLED-UVOPD集成器件中表现出优异的性能,紫外探测率分别为7.18×10^(11)和2.85×10^(12)Jones,最大EQE分别为8.7%和5.9%.

基于高通量测序技术分析四川两个奶牛场乳汁的菌群差异

【目的】本试验测定了两个奶牛场健康乳汁和乳房炎乳汁中微生物菌群的变化,以揭示不同奶牛场之乳汁菌群的异同,评估其对乳汁代谢的影响是否相同。【方法】采用16S rRNA高通量测序技术,分别测定两个奶牛场6头健康奶牛和6头乳房炎奶牛乳汁中微生物16S rRNA V4区序列,并对菌群群落结构和多样性进行比较,分析场内及场间的乳汁菌群差异。【结果】四组乳汁样本共获得4013234条原始序列,经过滤后获得2887024条优化序列。Alpha多样性Chao指数、Ace指数、Shannon指数、Simpson指数差异均不显著(P>0.05);Beta多样性四组样本均分别聚类;在场1和场2中,引起奶牛乳房炎的优势菌属分别是克雷伯氏菌属和埃希氏菌属;在2个奶牛场的健康乳汁中,场2的埃希氏菌属、葡萄球菌属的丰度显著高于场1;在2个奶牛场的乳房炎乳汁中,场2的埃希氏菌属、乳球菌属的丰度显著高于场1;2个奶牛场健康乳汁中的嗜冷菌总丰度分别为31.87%和38.72%;关联分析及功能预测分析表明,2个奶牛场健康乳汁与乳房炎乳汁优势物种之间的关系差异较大;场1无论是Level 1还是Level 2水平,均发现显著性差异的代谢通路,而场2均未发现显著性差异的代谢通路。【结论】本试验研究了两个奶牛场健康乳汁和乳房炎乳汁微生物菌群之间的异同,为两个奶牛场在乳房炎的预防工作以及原料奶在冷链运输过程中质量控制提供理论依据。

基于16S rDNA扩增子测序技术揭示真胃左方变位对奶牛粪便微生物的影响

【目的】本试验旨在测定产后健康奶牛和罹患真胃左方变位(left displacement of the abomasum,LDA)奶牛粪便中微生物菌群的变化,以期探讨LDA发生与菌群的关联性,评估其对机体代谢的潜在影响。【方法】采用16S rDNA高通量测序技术,测定10头健康奶牛(Health)、10头真胃左方变位奶牛(LDA)粪便中微生物16SrDNAV3–V4区序列,并对菌群群落结构和多样性进行比较,分析其与LDA发生的相关性。【结果】多样性分析表明,Health组与LDA组奶牛的粪便中微生物多样性和群落组成存在较大的差异,其中LDA奶牛粪便微生物具有较高的物种丰度和种群差异性。对门、科、属3个分类水平上最大丰度排名前10的物种进行分析发现,LDA奶牛疣微菌门、蓝菌门、变形菌门、梭杆菌门、拟杆菌科、p-2534-18B5菌科、艰难杆菌科、梭杆菌科、螺旋菌属、5-7N15菌属和梭杆菌属的丰度显著升高(P<0.05),而螺旋体门、TM7菌门、瘤胃球菌科、理研菌科、密螺旋体属的丰度显著下降(P<0.05)。功能预测分析表明,LDA奶牛碳水化合物代谢和脂质代谢通路相关功能基因显著上调,而遗传信息处理相关功能基因显著下调。【结论】本试验研究了健康奶牛和LDA奶牛粪便微生物的变化,为LDA的致病机理、早期诊断提供了理论依据与研究基础。