Proteomic analysis of latex from Jatropha curcas L. stems and comparison of two classic proteomic sample isolation methods: The phenol extraction and the TCA/acetone extraction

BackgroundJatropha curcas is a wide-spreading latex-rich biodiesel plant with high oil content in seeds that have always been under intense studies. However, studies are lacking on the latex component that is considered rich in proteins with potentially important physiological functions and secondary metabolites that are a promising source for new drugs. The proteomic analysis, which would be the first step to study these substances, was hampered by the presence of interfering components. Phenol extraction and Trichloroacetic acid (TCA)/acetone extraction, two major plant proteomic isolation methods, were used and compared in this study.ResultsWe identified 459 proteins from the J. curcas latex proteome using the combination of the two extraction techniques. Although more number of latex proteins were identified by the phenol extraction (401 proteins vs. 123 proteins by the TCA/acetone extraction), only 65 proteins were commonly isolated by both methods. Analysis of the biochemical properties revealed that relatively more number of lower isoelectric point (pI) proteins were isolated by the TCA/acetone method (pI mode: 4.79, 6.51 for phenol). Moreover, GO, COG, and KEGG analyses showed that certain classes/categories/pathways annotated more number of proteins than others, and most of them had proportionally comparable protein counts by both the methods, however, with exemplified exceptions.ConclusionsA large number of proteins were found and exclusively identified by either method, indicating that a better proteome coverage of plant samples in a similar context needs the combined use of multiple isolation methods. In addition, the core biological function of the latex may be uncovered by certain GO, COG, and KEGG classes/categories/pathways that annotate more proteins.     

Identification and characterization of a novel 2R,3R-Butanediol dehydrogenase from Bacillus sp. DL01

Background2R,3R-butanediol dehydrogenase (R-BDH) and other BDHs contribute to metabolism of 3R/3S-Acetoin (3R/3S-AC) and 2,3-butanediol (2,3-BD), which are important bulk chemicals used in different industries. R-BDH is responsible for oxidizing the hydroxyl group at their (R) configuration. Bacillus species is a promising producer of 3R/3S-AC and 2,3-BD. In this study, R-bdh gene encoding R-BDH from Bacillus sp. DL01 was isolated, expressed and identified.ResultsR-BDH exerted reducing activities towards Diacetyl (DA) and 3R/3S-AC using NADH, and oxidizing activities towards 2R,3R-BD and Meso-BD using NAD⁺, while no activity was detected with 2S,3S-BD. The R-BDH showed its activity at a wide range of temperature (25°C to 65°C) and pH (5.0–8.0). The R-BDH activity was increased significantly by Cd²⁺ when DA, 3R/3S-AC, and Meso-BD were used as substrates, while Fe²⁺ enhanced the activity remarkably at 2R,3R-BD oxidation. Kinetic parameters of the R-BDH from Bacillus sp. DL01 showed the lowest K_m, the highest V_max, and the highest K_cat towards the racemic 3R/3S-AC substrate, also displayed low K_m towards 2R,3R-BD and Meso-BD when compared with other reported R-BDHs.ConclusionsThe R-BDH from Bacillus sp. DL01 was characterized as a novel R-BDH with high enantioselectivity for R-configuration. It considered NAD⁺ and Zn²⁺ dependant enzyme, with a significant affinity towards 3R/3S-AC, 2R,3R-BD, and Meso-BD substrates. Thus, R-BDH is providing an approach to regulate the production of 3R/3S-AC or 2,3-BD from Bacillus sp. DL01.How to cite: Elmahmoudy M, Elfeky N, Zhongji P, et al. Identification and characterization of a novel 2R,3R-Butanediol Dehydrogenase from Bacillus sp. DL01. Electron J Biotechnol 2021;49. https://doi.org/10.1016/j.ejbt.2020.11.002     

Interleukin-1 receptor antagonist gene polymorphism and obesity: A pilot study from north India

The main adverse consequences of excess bodyweight are cardiovascular disease, type II diabetes, and several cancers, IL-1Ra serum concentration has been reported earlier to increase in human obesity and it is therefore assumed that the polymorphism of IL-1Ra may influence cytokine production. We designed this study to investigate whether the IL-1Ra polymorphism was associated with obesity. A total number of 103 individuals; 19 lean (BMI<25 Kg/m²), 51 overweight (BMI 25–29.9 Kg/m²) and 33 obese (BMI≥30.0 Kg/m²) were enrolled in this study. Genotyping was performed using a polymerase chain reaction PCR amplification of the intron-2 fragment harboring a variable number of tandem repeat (VNTR) nucleotide sequences 86 pb of tandem repeat. The PCR products were separated on 2% agarose gel. Statistical analysis was performed using SPSS software (version 11.5). We found no significant difference in genotype and allele frequencies between the three groups; lean vs. overweight and lean vs. obese (p=0.323; 0.202; 0.123 and 0.068 resp). However, an increased risk for obesity had a propensity to be higher in those having genotype II/II. This genotype has been reported to be a ‘high producer’ of IL-1Ra. Although no statistically significant relationship between IL-1Ra polymorphism and BMI was observed, however, a trend towards an increase of allele^*II in overweight and obese group was observed. This may suggest that IL-1Ra appears to be induced by inflammatory stimuli as well as obesity-associated factors. This is relatively a pilot study: but nevertheless, may assist in identifying the pathophysiological cause for obesity.     

搜索引擎偏见:合理性与不合理性——从百度竞价排名风波说起

百度竞价风波是搜索引擎偏见的典型体现。以竞价排名为特征的搜索引擎偏见与生俱来,具有一定的合理性,同时也具有严重的消极后果:伤害了新闻自由和个人自治,破坏了民主制度的基础和市场规则,违反了相关法律。如何减少和消除搜索引擎偏见,维护新闻自由,维持媒介市场秩序,促进个人和组织自治,推进民主进程,推动人类全面发展,值得深思。     

The Concept of Information Overload: A Review of Literature from Organization Science, Accounting, Marketing, MIS, and Related Disciplines

Based on literature from the domains of organization science, marketing, accounting, and management information systems, this review article examines the theoretical basis of the information overload discourse and presents an overview of the main definitions, situations, causes, effects, and countermeasures. It analyzes the contributions from the last 30 years to consolidate the existing research in a conceptual framework and to identify future research directions.     

The Concept of Information Overload: A Review of Literature from Organization Science,Accounting, Marketing,MIS, and Related Disciplines

Based on literature from the domains of organization science, marketing, accounting, and management information systems, this review article examines the theoretical basis of the information overload discourse and presents an overview of the main definitions, situations, causes, effects, and countermeasures. It analyzes the contributions from the last 30 years to consolidate the existing research in a conceptual framework and to identify future research directions.     

技术资本、高管团队异质性与企业成长——国有与民营企业的对比分析

选取国有与民营企业为样本,构建动态面板模型,实证分析了技术资本、高层管理团队(TMT)异质性与企业成长的内在关系。研究发现,国有、民营企业技术资本投入对成长能力具有明显的提升作用。所不同的是,国有样本TMT受教育水平、职业背景异质性对技术资本的调节及对成长能力的提升较显著,但TMT年龄与任期异质性的影响不明显。民营样本TMT职业背景、任期异质性对技术资本的调节及对成长能力的提升较显著,但TMT受教育水平与年龄异质性的影响不明显。     

互联网发展与技术创新：专利生产、更新与引用视角

本文在理论上分析互联网发展对技术创新的可能影响机制,利用2007—2014年我国230个地级市的面板数据,通过主成分分析法构建了互联网发展指数。并进一步应用工具变量法实证研究了互联网发展对技术创新产生的影响及其内在传导机制。本文采用1984年各城市每百人固定电话数量与电信投资量的交互项作为研究的工具变量。实证表明：（1）无论从专利数据还是城市创新指数来看,互联网发展都显著促进了技术创新;（2）互联网发展加速了专利的折旧速度,有利于提高创新知识的更新速度;（3）互联网发展加快信息的传播,提升了专利的国内外引用,显著增加了创新知识的溢出。本文为我国“互联网＋”行动计划、创新型国家建设奠定了理论与事实基础。     

Capturing information on technology convergence,international collaboration,and knowledge flow from patent documents: A case of information and communication technology

In addressing persistent gaps in existing theories, recent advances in data-driven research approaches offer novel perspectives and exciting insights across a spectrum of scientific fields concerned with technological change and the socio-economic impact thereof. The present investigation suggests a novel approach to identify and analyze the evolution of technology sectors, in this case, information and communications technology (ICT), considering international collaboration patterns and knowledge flows and spillovers via information inputs derived from patent documents.The objective is to utilize and explore information regarding inventors’ geo-location, technology sector classifications, and patent citation records to construct various types of networks. This, in turn, will open up avenues to discover the nature of evolutionary pathways in ICT trajectories and will also provide evidence of how the overall ICT knowledge space, as well as directional knowledge flows within the ICT space, have evolved differently. It is expected that this data-driven inquiry will deliver intuitive results for decision makers seeking evidence for future resource allocation and who are interested in identifying well-suited collaborators for the development of potential next-generation technologies. Further, it will equip researchers in technology management, economic geography, or similar fields with a systematic approach to analyze evolutionary pathways of technological advancements and further enable exploitation and development of new theories regarding technological change and its socio-economic consequences.     

钢城·诗城·英雄城——从马鞍山区划变更谈起

马鞍山地区历史悠久,山水文化之盛与交通便利造就了无数名人名篇。2011年,马鞍山行政区划调整之后,在扩大地域范围的同时,文化内涵也得到了极大的丰富。     

学术创业的边界、绩效与争议——基于1990-2014年文献的扎根分析

选取1990-2014年间国内外有关学术创业的102篇重要文献进行扎根分析,提炼出298个编码、8个概念和4个主范畴,将学术创业的边界扩展至社会创业,在此基础上,重新审视学术创业绩效并澄清研究争议,归纳出学术创业的研究逻辑,并提出未来研究的5个新的研究命题.     

盈利结构质量、核心盈利能力与盈利持续性——来自我国A股制造业上市公司的经验证据

盈利持续性是衡量盈利质量的重要手段,对投资者预测公司未来的发展前景具有重要意义.本文在我国新会计准则的财务信息披露模式下,对公司的盈利结构展开全面分析,构建出一套基于核心盈利能力的盈利结构质量评价指标体系,并以制造业A股上市公司2006-2008年的财务数据为基础采用因子分析法对该指标体系的有效性进行了实证检验.研究结果表明:公司的核心盈利能力越强,盈利结构质量越高,盈利的持续性就越好;而核心盈利能力较弱的公司,其盈利结构中非持续性的盈利项目往往占比过大,从而导致盈利的持续性较差.本文得出如下结论:核心盈利能力和盈利结构质量是影响盈利持续性的重要因素,文中提出的盈利结构质量评价指标体系对公司的盈利持续性具有较好的预测能力.