The protective effects of grape seed procyanidin B2 against asporin mediates glycated low‐density lipoprotein induced‐cardiomyocyte apoptosis and fibrosis

The progression of diabetic cardiomyopathy is related to cardiomyocyte dysfunction and apoptosis. Our previous studies showed that asporin (ASPN) was significantly increased in the myocardium of db/db mice through proteomics, and grape seed procyanidin B2 (GSPB2) significantly inhibited the expression of ASPN in the heart of db/db mice. We report here that ASPN played a critical role in glycated low‐density lipoproteins (gly‐LDL) induced‐cardiomyocyte apoptosis. We found that gly‐LDL upregulated ASPN expression. ASPN increased H9C2 cardiomyocyte apoptosis with down‐regulation of Bcl‐2, upregulation of transforming growth factor‐β1, Bax, collagen III, fibronectin, and phosphorylation of smad2 and smad3. However, GSPB2 treatment reversed ASPN‐induced impairments in H9C2 cardiomyocytes. These results provide evidence for the cardioprotective action of GSPB2 against ASPN injury, and thus suggest a new target for fighting against diabetic cardiomyopathy.     

MALDI-TOF-MS and 16S rRNA characterization of lead tolerant metallophile bacteria isolated from saffron soils of Kashmir for their sequestration potential

Toxic metal contamination in soils due industrialization is nowadays a concern to the scientists worldwide. The current study deals with the evaluation of response and tolerance by isolated metallophilic bacteria in different lead concentrations (100 ppm to 1000 ppm). By taking optical densities of the isolates, the minimum inhibitory concentration (MIC) of Pb²⁺ were determined.16S rRNA and MALDI-TOF MS were used for the identification of the bacteria. Total of 37 isolates were observed, among them 04 (Staphylococcus equorum, Staphylococcus warneri, Bacillus safensis and Bacillus thuringiensis), isolated were detected having efficacy of Pb²⁺tolerance and sequestration at varying MIC. Furthermore, B. thuringiensis was observed to have highest (900 ppm) tolerance for lead and lowest (500 ppm) for Staphylococcus warneri. Moreover, the highest (65.3%) sequestration potential has been observed for B. thuringiensis and least (52.8%) for S. warneri. The tolerance and sequestration potential properties of these isolated species can be utilised to exterminate heavy metals and reduce their toxicity from the contaminated environment.     

X‐ray crystallographic structure of BshB,the zinc‐dependent deacetylase involved in bacillithiol biosynthesis

Many gram‐positive bacteria produce bacillithiol to aid in the maintenance of redox homeostasis and degradation of toxic compounds, including the antibiotic fosfomycin. Bacillithiol is produced via a three‐enzyme pathway that includes the action of the zinc‐dependent deacetylase BshB. Previous studies identified conserved aspartate and histidine residues within the active site that are involved in metal binding and catalysis, but the enzymatic mechanism is not fully understood. Here we report two X‐ray crystallographic structures of BshB from Bacillus subtilis that provide insight into the BshB catalytic mechanism.     

GA3处理对低温胁迫条件下玉米种子呼吸代谢的影响

以低温敏感型的"丰禾1号"和耐低温型的"郑单958"两个玉米品种为实验材料,采用GA3浸种的处理方式("丰禾1号"为20 mg·L-1、"郑单958"为5 mg·L-1),探究了GA3对低温胁迫条件下玉米种子萌发过程中种胚中可溶性糖和可溶性蛋白含量及淀粉酶活性和呼吸途径关键酶活性的影响。结果表明:低温胁迫条件下,GA3浸种处理显著提升了玉米种胚中可溶性糖含量及可溶性蛋白的积累,增强了低温胁迫下细胞的渗透势;α-淀粉酶、β-淀粉酶和总淀粉酶活性显著提高;提高了苹果酸脱氢酶(MDH)、丙酮酸激酶(PK)、联合酶(G-6-PDH和6-PGDH)的活性,提高了糖酵解(EMP)、三羧酸循环(TCA)、磷酸戊糖途径(PPP)途径的运转效率,保证了细胞的物质代谢和能量供应;GA3浸种处理可以显著提高种子对低温的抵抗能力,从而在低温胁迫条件下促进其萌发。     

The Short‐Term Effect of Occupational Levels of 50 Hz Electromagnetic Field on Human Heart Rate Variability

Previous studies have indicated that there is no consensus on the effects of extremely low‐frequency electromagnetic (ELF‐EMF) exposure on the cardiovascular system. This study aimed to explore the short‐term effect of ELF‐EMF exposure on heart rate (HR) and HR variability (HRV). The sample consisted of 34 healthy males aged 18–27 years. The participants were randomly assigned to the EMF (n = 17) or the Sham group (n = 17). We employed a double‐blind repeated‐measures design consisting of three 5 min experimental periods. The chest region of each individual in the EMF group was exposed to 50 Hz, 28 μT, linear polarized, continuous EMF during the EMF exposure period. HR and HRV data were recorded continuously by using a photoplethysmography sensor. Within‐subject statistical analysis indicated a significant HR deceleration in both the EMF and Sham groups. However, the standard deviation of the NN intervals (SDNN), root mean square of successive differences (RMSSD), low‐frequency (LF), and high‐frequency (HF) powers increased only in the EMF group and remained stable in the Sham group. We also compared the same HRV indices measured during the EMF and Sham periods between the two experimental groups. The between‐subject analysis results demonstrated significantly higher SDNN, RMSSD, LF, and HF values in the EMF group than in the Sham group. The LF/HF ratio did not change significantly within and between groups. On the basis of these results, we concluded that short‐term exposure of the chest region to ELF‐EMF could potentially enhance parasympathetic predominance during the resting condition. Bioelectromagnetics. 2021;42:60–75. © 2020 Bioelectromagnetics Society.     

面向低碳城市建设的建筑运行能耗驱动机理研究进展

城市快速扩张的同时,不断增大的建筑存量、建筑运行能耗及相应的碳排放成为制约城市可持续发展的重要因素。为实现节能降耗,有必要对建筑能耗碳排放的驱动机理进行深入探究。已有研究从不同角度对建筑运行能耗碳排放的影响要素和驱动机理进行了分析论证,但仍缺乏系统综述从而难以为建筑节能降耗提供全面指导。本文基于“社会-经济-自然”复合生态系统理论,对驱动建筑能耗碳排放的复合机理进行综合论述;在此基础上,从社会经济、建筑体特征、区域气候/微气候等视角,整合并剖析了不同单源要素的建筑能耗碳排放驱动机理;最后,总结了当前城市建筑能耗驱动机理研究领域存在的不足,并对未来发展进行了展望。本文对建筑能耗碳排放驱动机理的系统梳理和总结,对相关研究具有重要的参考价值,对低碳城市建设亦具有重要的科技支撑作用。     

既主内政, 又辖外交——以PHR为中心的基因网络调控植物-菌根真菌的共生

磷是植物生长发育必需的大量矿质营养元素, 但自然界大部分土壤都存在严重缺磷的问题。为了适应这一营养逆境, 植物演化出一系列低磷胁迫应答反应。通过改变基因的转录水平调控低磷胁迫应答反应, 而转录因子PHR1在调控植物对低磷胁迫的转录响应中起关键作用。此外, 大部分陆生植物还能与丛枝菌根真菌建立共生关系, 通过丛枝菌根真菌更有效地从土壤中获取磷元素。最近, 中国科学院分子植物科学卓越创新中心王二涛研究组发现, 以PHR为中心的转录调控网络控制植物-丛枝菌根真菌共生的建立。因此, PHR不但在维持植物细胞自身的磷稳态中发挥作用, 而且参与植物与外界微生物的相互作用, 为植物有效地从环境中获得磷元素提供了另外一条途径。