Formation of Bromate Ion Through a Radical Pathway in a Continuous Flow Reactor

The contribution of ozone and hydroxyl radical to the formation of bromate ion was investigated in a continuous flow reactor. Experiments were conducted under a wide range of ozone dose (0.7 ～ 3.8 mgL), pH (6.5 ～ 8.5), and t-butanol concentration (0 ～ 0.5 mM). The formation of bromate ion was found to depend on radical reaction pathway, because the amount of bromate ion formed increased with pH and decreased with t-butanol, a radical scavenger, even when dissolved ozone concentrations were almost the same. In fact, the amount of bromate ion formed was reduced by 90% in the presence of t-butanol. Furthermore, the formation of bromate ion occurred even when dissolved ozone was not significantly detected in the presence of organic matter (TOC of 1 mgCL). The second-order reaction rate constant of hydroxyl radical with bromide ion, k _HO,Br^? of 1.7 × 10⁹ (M^?1s^?1), was obtained on the assumption that the reactions of bromide ion and t-butanol with hydroxyl radical were competitive with each other in the presence of t-butanol and that the formation of bromate ion depended on the reaction of bromide ion with hydroxyl radical. Therefore, it is concluded that the reaction of bromide ion with hydroxyl radical dominated in the overall reaction from bromide ion to bromate ion in the continuous flow reactor.     

Ascorbate enhances iron uptake into intestinal cells through formation of a FeCl3–ascorbate complex

It has been well documented that ascorbate enhances iron uptake, with a proposed mechanism based on reduction to the more absorbable ferrous form. We have performed a study on the effects of ascorbate on ferric iron uptake in the human epithelial Caco-2 cell-line. Ascorbate increased uptake in a concentration-dependent manner with a significant difference between iron uptake and reduction. Uptake kinetics are characteristic of a non-essential activator and the formation of an Fe³⁺–ascorbate complex. This investigation provides evidence that ascorbate enhances the apical uptake of ferric iron into Caco-2 cells through the formation of a Fe³⁺–ascorbate complex.     

海洋生物通过海水途径对铯,钴,锌的浓集与排出研究

本文报道了海洋生物通过海水途径对铯，钴，锌的浓集与排出研究的实验结果。实验生物为珍珠贝，梭子蟹，黑鲷和扇贝，均取自广东大亚湾海域，在分别含一定浓度的Ｃｓ，Ｃｏ或Ｚｎ的海水中培养７ｄ。进行浓集实验，然后以浅海挂养或清洁海水池养的方式进行排出实验，用原子吸收分光光度计测定生物不同组织或器官中元素的含量。     

Nuclear regulation of mitochondrial functions during oocyte development

Mitochondria are important in eukaryotic cells due to their functions in energy production and regulation over other cellular activities. Oocytes are produced by a long and precisely controlled process, the dysfunction of which leads to impaired female fertility. As oocytes mature, mitochondria are constantly under the regulation of nuclear genes, the process of which can be modulated by extracellular signals. Understanding how nuclear genes regulate mitochondrial functions is important for studying animal reproduction and human fertility. As more and more genes regulating mitochondrial functions in oocytes are being revealed, new approaches for improving female fertility in both human and animals through mitochondria can be developed.     

Meta-Analysis of Methamphetamine Modulation on Amyloid Precursor Protein through HMGB1 in Alzheimer’s Disease

The deposition of amyloid-beta (Aβ) through the cleavage of amyloid-beta precursor protein (APP) is a biomarker of Alzheimer’s disease (AD). This study used QIAGEN Ingenuity Pathway Analysis (IPA) to conduct meta-analysis on the molecular mechanisms by which methamphetamine (METH) impacts AD through modulating the expression of APP. All the molecules affected by METH and APP were collected from the QIAGEN Knowledge Base (QKB); 78 overlapping molecules were identified. Upon simulation of METH exposure using the “Molecule Activity Predictor” feature, eight molecules were found to be affected by METH and exhibited activation relationships on APP expression at a confidence of p = 0.000453 (Z-score = 3.51, two-tailed). Core Analysis of these eight molecules identified High Mobility Group Box protein 1 (HMGB1) signaling pathway among the top 5 canonical pathways with most overlap with the 8-molecule dataset. Simulated METH exposure increased APP expression through HMGB1 at a confidence of p < 0.00001 (Z-score = 7.64, two-tailed). HMGB1 is a pathogenic hallmark in AD progression. It not only increases the production of inflammatory mediators, but also mediates the disruption of the blood-brain barrier. Our analyses suggest the involvement of HMGB1 signaling pathway in METH-induced modulation of APP as a potential casual factor of AD.     

基于大鼠血清差异蛋白质组学小白杏杏仁油免疫调节作用研究

采用i TRAQ标记及高效液相色谱-电喷雾串联质谱(LC-ESI-MS/MS)技术对小白杏杏仁油干预试验大鼠血清差异表达蛋白进行定量鉴定,并通过表达模式及代谢通路聚类对鉴定获得的差异蛋白进行生化代谢途径和信号转导途径分析。结果表明,小白杏杏仁油可能通过调节血清中结合珠蛋白(HP)、角蛋白(KRT10、KRT42)、微管蛋白α-8链(TUBA8)、免疫球蛋白重(k)链VⅢ区(VH26、MOPC63)、α-1-抗蛋白酶(SERPINA1)及T-激肽原(KNG1)等蛋白的表达水平,作用于金黄色葡萄球菌感染、吞噬体、致病性大肠杆菌感染、原发性免疫缺陷、补体和凝血级联5条先天性免疫通路而展现其免疫调节作用。     

低剂量γ射线辐照对人淋巴母细胞基因表达转录谱的影响

为探讨低剂量电离辐射生物效应作用机制,本文研究了不同剂量单次辐照后,人淋巴母细胞基因表达转录谱的变化。采用0．1Gy、0．5Gy和1．0Gy剂量的γ射线照射人淋巴母细胞,未照射细胞为对照组。照射后4h提取细胞总RNA,用含有45033个基因的人类全基因组表达谱芯片检测分析。对差异表达基因进行层次聚类分析、基因本体论分析和通路分析,并用实时荧光定量PCR验证。结果表明,3个剂量组均上调表达的基因1330个,下调表达的基因1002个。基因表达量与吸收剂量相关的基因共18个,其中与剂量正相关的基因16个,负相关的基因2个。层次聚类分析结果表明,4个实验组中,0．1Gy和1．0Gy照射组差异表达基因相似程度最高。这些差异表达的基因涉及到多条通路,如细胞周期、p53信号通路、碱基切除修复、RNA转运和内质网蛋白加工等。实时荧光定量PCR检测结果表明,CASP9（caspase9）mRNA在照射后4h随吸收剂量表达变化与基因芯片检测结果一致。基因芯片筛选出的差异表达基因有助于阐明低剂量辐射生物效应作用机理,与辐射剂量相关的差异表达基因有可能成为低剂量辐射暴露的生物剂量计。     

The influences of multi-walled carbon nanotube addition to the anode on the performance of direct methanol fuel cells

Different amounts of multi-walled carbon nanotubes (MWCNTs) are added to anode catalyst layer in the membrane electrode assemblies (MEAs) of direct methanol fuel cells (DMFCs). The MEA with 0.5 wt.% carbon nanotubes (CNTs) shows the best performance in DMFC. In the protonic conductivity tests, a 0.5 wt.% amount of MWCNTs results in the highest protonic conductivity. SEM and TEM observations show that a continuous and uniform distribution of Nafion ionomer layer is formed on the MWCNT surface. Therefore, the dispersed MWCNTs in the catalyst layer are considered to be helpful for developing the pathways of protons transport.     

A Simple Model to Predict Formation of Bromate Ion and Hypobromous Acid/Hypobromite Ion through Hydroxyl Radical Pathway during Ozonation

A simple model is developed to predict the formation of bromate ion as well as hypobromous acid/hypobromite ion through the hydroxyl radical pathway. For simplicity of the model, hydroxyl radical concentrations are represented by the concentration ratio of hydroxyl radical to dissolved ozone under the different pH conditions. A kinetic analysis is conducted to evaluate the ratio under the different pH conditions based on the experimental data. The different extent of the ratio by one pH unit is found to be 3–4 times. This model can favorably simulate the formations of bromate ion as well as hypobromous acid/hypobromite ion in spite of the simplicity of the model. So it is likely that this model will be applicable to the prediction of bromate ion formation in water purification process such as drinking water treatment by introducing the concentration ratio of hydroxyl radical to dissolved ozone.     

Successful pathway for locally driven fuel cell electric vehicle adoption: Early evidence from South Korea

South Korea is an outstanding pioneer of fuel cell electric vehicle (FCEV) technology, an industry that is fundamental to the hydrogen ecosystem. This study aims to explore possible pathways for the successful adoption of FCEV in the local region. By using the fuzzy-set quality comparative analysis (fs/QCA) method, we identify three auspicious pathways based on the 16 regional cases in Korea. We find that, first, a large number of hydrogen (H₂) stations will lead to successful FCEV adoption (H₂ STATION→FCEV). Second, the combination of high levels of greenhouse gases(GHGs) and the local government-driven future construction plans of H₂ stations can also be a remarkable pathway (GHGs1 PLAN→FCEV). Lastly, a combination of high levels of GHGs and subsidies can be another compelling pathway (GHGs1 SUBSIDIES→FCEV). This study provides early evidence of FCEVs adoption and can be of use to latecomer countries to the hydrogen economy.