Green and efficient biosynthesis of indigo from indole by engineered myoglobins

With the demand nowadays for blue dyes, it is of practical importance to develop a green and efficient biocatalyst for the production of indigo. The design of artificial enzymes has been shown to be attractive in recent years. In a previous study, we engineered a single mutant of sperm whale myoglobin, F43Y Mb, with a novel Tyr-heme cross-link. In this study, we found that it can efficiently catalyze the oxidation of indole to indigo, with a yield as high as 54% compared to the highest yield (∼20%) reported to date in the literature. By further modifying the heme active site, we engineered a double mutant of F43Y/H64D Mb, which exhibited the highest catalytic efficiency (198 M⁻¹ s⁻¹) among the artificial enzymes designed in Mb. Moreover, both F43Y Mb and F43Y/H64D Mb were found to produce the indigo product with a chemoselectivity as high as ∼80%. Based on the reaction system, we also established a convenient and green dyeing method by dyeing a cotton textile during the biosynthesis of indigo, followed by further spraying the concentrated indigo, without the need of strong acids/bases or any reducing agents. The successful application of dyeing a white cotton textile with a blue color further indicates that the designed enzyme and the dyeing method have practical applications in the future.

Myoglobin (Mb) was redesigned to a green and efficient biocatalysts for the biosynthesis of indigo from indole, exhibiting improved yield, catalytic efficiency and chemoselectivity (as high as ∼80%).     

Brain Natriuretic Peptide for Prevention of Contrast-Induced Nephropathy After Percutaneous Coronary Intervention or Coronary Angiography

BackgroundMany methods reportedly prevent contrast-induced nephropathy (CIN), but the effect of brain natriuretic peptide (BNP) on CIN is unknown. In this study we investigated recombinant BNP use before coronary angiography (CA) or nonemergent percutaneous coronary intervention (PCI) in patients with unstable angina.MethodsOne thousand patients with unstable angina were prospectively evaluated. The patients were randomly assigned to: group A, isotonic normal saline (NaCl 0.9%, 1 mL/kg/h) for 24 hours before CA or PCI; and group B, human recombinant BNP (rhBNP; 0.005 μg/kg/min). Serum creatinine (Scr) levels and estimated glomerular filtration rate were measured before and 24, 48, and 72 hours, and 7 days after the procedure. The primary outcome was CIN incidence defined according to a relative (≥ 25%) or absolute (≥ 0.5 mg/dL and 44 μmol/L, respectively) increase in Scr from baseline within 48 hours. The secondary end points were the changes in the Scr and estimated glomerular filtration rate, before and after the procedure.ResultsContrast volume, a history of diabetes mellitus, and BNP administration independently predicted CIN. The incidence of CIN was significantly greater in group A than in group B (14.8% vs 5.6%; P < 0.01). Renal function was less compromised in patients who received rhBNP. The Scr of all patients with CIN remained increased for 24 hours, but it was lower and recovered faster in patients who received rhBNP.ConclusionsrhBNP administration before CA or PCI protects renal function and can significantly decrease CIN incidence.     

半夏基因组DNA的提取及鉴定

目的探讨不同DNA提取方法对半夏DNA质量及RAPD-PCR标记结果的影响。方法对用不同方法提取的DNA进行电泳、紫外吸收A260/A280和RAPD-PCR分析。结果不同方法提取的DNA质量和产率差异不显著,对RAPD结果无影响。结论半夏在DNA提取前加入氯仿对材料预处理,可获得较高质量的DNA进行PCR扩增。     

A nano-sized Cu-MOF with high peroxidase-like activity and its potential application in colorimetric detection of H2O2 and glucose

Peroxidase widely exists in nature and can be applied for the diagnosis and detection of H₂O₂, glucose, ascorbic acid and other aspects. However, the natural peroxidase has low stability and its catalytic efficiency is easily affected by external conditions. In this work, a copper-based metal–organic framework (Cu-MOF) was prepared by hydrothermal method, and characterized by means of XRD, SEM, FT-IR and EDS. The synthesized Cu-MOF material showed high peroxidase-like activity and could be utilized to catalyze the oxidation of o-phenylenediamine (OPDA) and 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H₂O₂. The steady-state kinetics experiments of the oxidation of OPDA and TMB catalyzed by Cu-MOF were performed, and the kinetic parameters were obtained by linear least-squares fitting to Lineweaver–Burk plot. The results indicated that the affinity of Cu-MOF towards TMB and OPDA was close to that of the natural horseradish peroxidase (HRP). The as-prepared Cu-MOF can be applied for colorimetric detection of H₂O₂ and glucose with wide linear ranges of 5 to 300 μM and 50 to 500 μM for H₂O₂ and glucose, respectively. Furthermore, the specificity of detection of glucose was compared with other sugar species interference such as sucrose, lactose and maltose. In addition, the detection of ascorbic acid and sodium thiosulfate was also performed upon the inhibition of TMB oxidation. Based on the high catalytic activity, affinity and wide linear range, the as-prepared Cu-MOF may be used for artificial enzyme mimics in the fields of catalysis, biosensors, medicines and food industry.

A Cu-MOF with high peroxidase-like activity was prepared and could be used for colorimetric detection of H₂O₂ and glucose with high selectivity and good linear range (50–500 μM).     

大熊猫核糖体蛋白L10亚基基因的cDNA克隆及序列分析

目的 了解大熊猫(ailuropoda melanoleuca) 核糖体蛋白L10亚基基因(RPL10)的结构特点及其与已报道的人和其他哺乳动物核糖体蛋白亚基RPL10基因的异同. 方法根据已报道的部分哺乳动物RPL10基因的相关信息设计引物,运用RT-PCR技术,从大熊猫的肌肉组织总RNA 中对核糖体蛋白亚基RPL10 基因的进行克隆、测序;采用Genescan 软件,对所克隆的基因序列进行氨基酸序列推定;采用ORF finder软件进行DNA 序列的开放阅读框查找;采用DNAMAN Version 6软件,对基因序列和氨基酸序列进行同源性比较;采用Ex2PASy Proteomics Server 软件,进行蛋白质功能位点和生化特性预测分析;采用http://www.imtech.res.in/raghava/apssp2/对蛋白质二级结构进行模拟分析.结果 大熊猫RPL10基因的表达序列长为685 bp,开放阅读框(ORF)为645 bp,编码214个氨基酸的蛋白质,该蛋白的相对分子质量为24.599 7×103,等电点为10.74,含有4个功能位点,分别为:2个蛋白激酶C磷酸化位点,2个N化位点,2个酰胺化位点,1个核糖体蛋白L10e信号位点.进一步分析发现,该基因的表达序列及其编码的氨基酸序列与已报道的人、牛、家犬、褐家鼠、小家鼠有很高的相似性,其表达序列同源性分别为92.4%、92.4%、97.21%、88.84%与89.61%;其编码的氨基酸序列除与牛的同源性为99.07%外,与其他哺乳动物同源性为100%.而且,其蛋白质的高级结构除牛外其他物种也具有一致性.结论 无论是从RPL10基因的序列、结构、功能位点,还是从其编码的氨基酸的序列和二级结构进行分析,都表明大熊猫的RPL10基因和已报道的哺乳动物的RPL10基因具有高度的遗传稳定性和功能一致性.     

父母教养方式对中专生身心健康的影响

目的探讨父母教养方式对中专生身心的影响，为中专生的健康促进提供依据。方法采用父母教养方式评价量表（EMBU）和症状自评量表（SCL-90），对南充市两所中专学校190名一年级新生进行测查。结果症状自评量表筛查出有心理问题者19人，占10.50%。父亲惩罚严厉、偏爱被试与SCL-90躯体化和敌对因子呈显著正相关；母亲情感温暖、理解与躯体化呈显著负相关，过干涉和过保护与总分、躯体化、敌对和恐怖因子呈显著正相关，而母亲惩罚严厉与SCL-90总分及各因子呈显著正相关。结论父母教养方式与中专生身心健康密切相关。     

谈PBL的理论与实践

PBL是一种让学生在真实情境中思考、学习和行动的实验教学法,是建构主义理论指导下的一种新的教学模式.目前,PBL已从当初的医学教育领域走向其它学科教育领域.文章以PBL在<教育传播科学研究方法>中的应用为例,阐述了PBL的教学流程.     

头脑风暴法在Webquest教学模式中的应用

介绍了头脑风暴法在Webquest教学模式中的融合流程,通过对Webquest教学流程的分析,在参照头脑风暴法与Wequest应用原则的基础上,总结出融入头脑风暴思想后Webquest的教学设计流程.调查发现,在课堂教学过程中应用头脑风暴法,不仅可以提高学生的学习兴趣,而且可以高效提高学生的创造性思维能力,为教学效果的改善以及创新型人才的培养提供有力保障.     

数据挖掘在教学管理中的应用研究

数据挖掘是一种新的信息处理技术.文章在对数据挖掘进行概述的基础上,以某高校教务管理系统应用为例,说明在学校教学管理中,数据挖掘能从海量数据中找出有价值、有意义的数据,为教学管理的科学决策提供参考,既提高了教学管理工作的效率和质量,又减少了工作人员的工作量.