PM2.5 in China： Measurements,sources, visibility and health effects,and mitigation

Concern over the health effects of fine particles in the ambient environment led the U.S. Environmental Protection Agency to develop the first standard for PM2.5 （particulate matter less than 2.5 μm） in 1997. The Particle Technology Laboratory at the University of Minnesota has helped to establish the PM2.5 standard by developing many instruments and samplers to perform atmospheric measurements. In this paper, we review various aspects of PM2.5, including its measurement, source apportionment, visibility and health effects, and mitigation. We focus on PM2.s studies in China and where appropriate, compare them with those obtained in the U.S. Based on accurate PM2.5 sampling, chemical analysis, and source apportionment models, the major PM2.5 sources in China have been identified to be coal combustion, motor vehicle emissions, and industrial sources. Atmospheric visibility has been found to correlate well with PM2.s concentration. Sulfate, ammonium, and nitrate carried by PM2.s, commonly found in coal burning and vehicle emissions, are the dominant contributors to regional haze in China. Short-term exposure to PM2.s is strongly associated with the increased risk of morbidity and mortality from cardiovascular and respiratory diseases in China. The strategy for PMzs mitigation must be based on reducing the pollutants from the two primary sources of coal-fired power plants and vehicle emissions. Although conventional Particulate Emission Control Devices （PECD） such as electrostatic precipitators in Chinese coal-fired power plants are generally effective for large particles, most of them may not have high collection efficiency of PM2.5. Baghouse filtration is gradually incorporated into the PECD to increase the PM2.5 collection efficiency. By adopting stringent vehicle emissions standard such as Euro 5 and 6, the emissions from vehicles can be gradually reduced over the years. An integrative approach, from collaboration among academia, government, and industries, can effectively manage and mitigate the PM2.s p     

α-取代丙酸酯化合物在全甲基环糊精固定相上的手性拆分

在全甲基β-环糊精(PMBCD)手性固定相上,测定了20对α-取代丙酸酯类化合物对映体的手性分离行为,计算出18对对映体的热力学参数,并利用超热力学方法证明了其中17对对映异构体在PMBCD上的拆分存在焓熵补偿现象,即存在相同或基本一致的拆分机制。结合热力学参数,讨论了衍生基团、取代基团等因素对对映体分离的影响,论述了PMBCD固定相对这20对对映体的分子识别特性和保留机理。     

气相中苯二聚体离子结构的串联质谱研究

应用碰撞诱导解离技术研究了苯自身化学电离条件下和苯化学电离（甲苯为反应气）条件下离子－分子反应产物ｍ／ｚ１５５和１５６离子的碰撞诱导解离（ＣＩＤ）破裂特性，并与化学电离条件下质子化联苯生成ｍ／ｚ１５５离子的ＣＩＤ碎裂反应相比较，获得了苯离子１－分子反应产物ｍ／ｚ１５５和１５６离子的结构信息。     

Strategy and Chromatographic Technology of Quality Control for Traditional Chinese Medicines

The application of chromatography, a modern technology, for highly efficient separation and analysis in the research of therapeutic basis matter and quality control of traditional Chinese medicines (TCM), is summarized. A new strategy with metabonomics is put forth to achieve integral study on the therapeutic basis matter and the action mechanism of TCM and to reveal and control the comprehensive quality of TCM. The result shows that modern chromatography and hyphenated techniques are one of the important technique platforms in the quality control of TCM.     

Preparation of bipolar membranes via radiation peroxidation grafting

Single-sheet bipolar membranes have been prepared by grafting of styrene into radiation peroxidized LDPE films, which were then chlorosulfonated from one side, chloromethylated and quaternized from the other side. Various monomer systems were investigated and optimized. Obtained bipolar membranes were characterized by their specific electrical resistance, static potentials, rectification properties and water splitting capabilities.     

LC Determination of Malondialdehyde Concentrations in the Human Umbilical Vein Endothelial Cell Culture Medium: Application to the Antioxidant Effect of Vitexin-2″-O-rhamnoside

Vitexin-2″-O-rhamnoside (VOR) presents the leaves of Crataegus pinnatifida Bge. var. major which plays a role in preventing human pathologies related to oxidative stress, but as the principal component in the leaves, little attention has been devoted to its study of antioxidation of VOR. A simple, rapid and sensitive high-performance liquid chromatography method was developed to determine malondialdehyde (MDA) in ECV304 cell culture medium induced by tert-butyl-hydroperoxide (TBHP). The preparation of analyzed samples involved a one-step derivatization with thiobarbituric acid (TBA). The separation was achieved using the Synergi Hydro-RP, a polar endcapped C₁₈ column (250 × 4.6 mm, 4 μm pore size) with a linear gradient elution of acetonitrile and 10 mmol L^?1 of ammonium acetate aqueous solution (pH 6.8). The calibration curve was linear over the ranges 0.0125–1.25 μmol L^?1 MDA (r = 0.9962). The lower limit of quantification of MDA was 0.0125 μmol L^?1. Relative standard deviations of intra-day and inter-day precision were less than 5.2 and 4.4%. The method with high recovery (95.4 ± 1.3%) was successfully applied to the investigation of antioxidation of VOR by determining MDA in ECV304 cell culture medium.     

同位素稀释-气相色谱-质谱法检测大鼠血浆中的内源性胍丁胺

建立了大鼠血浆中内源性胍丁胺的同位素稀释-气相色谱-负化学电离质谱定量分析方法。大鼠血浆样品经蛋白沉淀并蒸干后,用六氟乙酰丙酮衍生化,采用Florisil固相萃取柱净化,以稳定同位素标记的d₈-胍丁胺为内标,在气相色谱-质谱仪上采用负化学电离方式电离,选择离子模式检测。胍丁胺标准溶液的检出限为0.0057 ng/mL。血浆中添加的胍丁胺在1.14~57.0 ng/mL范围内呈良好的线性关系（r=0.997）,方法回收率介于92.3%~109.8%之间,日内和日间精密度均小于15%。大鼠血浆中胍丁胺平均含量水平为（22±9）ng/mL,雌、雄大鼠血浆中的胍丁胺水平未见显著性差异（p>0.05）。该方法特异性好、灵敏度高,为生物体内胍丁胺的生理功能研究提供了高灵敏的分析方法。     

A Novel Synthetic Precursor of Styryl Sulfone Neuroprotective Agents Inhibits Neuroinflammatory Responses and Oxidative Stress Damage through the P38 Signaling Pathway in the Cell and Animal Model of Parkinson’s Disease

A novel class of styryl sulfones were designed and synthesized as CAPE derivatives by our work team, which showed a multi-target neuroprotective effect, including antioxidative and anti-neuroinflammatory properties. However, the underlying mechanisms remain unclear. In the present study, the anti-Parkinson’s disease (PD) activity of 10 novel styryl sulfone compounds was screened by the cell viability test and the NO inhibition test in vitro. It was found that 4d exhibited the highest activity against PD among them. In a MPTP-induced mouse model of PD, the biological activity of 4d was validated through suppressing dopamine neurotoxicity, microglial activation, and astrocytes activation. With compound 4d, we conducted the mechanistic studies about anti-inflammatory responses through inhibition of p38 phosphorylation to protect dopaminergic neurons, and antioxidant effects through promoting nuclear factor erythroid 2-related factor 2 (Nrf2). The results revealed that 4d could significantly inhibit 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine/1-methyl-4-phenylpyridinium (MPTP/MPP⁺)-induced p38 mitogen-activated protein kinase (MAPK) activation in both in vitro and in vivo PD models, thus inhibiting the NF-κB-mediated neuroinflammation-related apoptosis pathway. Simultaneously, it could promote Nrf2 nuclear transfer, and upregulate the expression of antioxidant phase II detoxification enzymes HO-1 and GCLC, and then reduce oxidative damage.     

基于主成分分析的骨碎补药材乙醇和环己烷提取物的高效液相色谱指纹图谱及指标成分的定量分析

建立了骨碎补药材乙醇和环己烷提取物的高效液相色谱(HPLC)指纹图谱,并利用主成分分析法(PCA)对指纹图谱进行统计分析,以各主要色谱峰的保留时间和峰面积为变量得到score图和loading图。在score图和loading图中,骨碎补的正品和非正品可明显区分,且揭示出对此区分贡献最大的4个潜在指标成分,其中已知成分为柚皮苷、新北美圣草苷和E-4-O-β-D-葡萄糖酰咖啡酸。同时测定了这3种成分在19批正品和非正品骨碎补药材中的含量,其中10批骨碎补药材正品中3种成分的含量为: 柚皮苷6.36～10.1 mg/g,新北美圣草苷5.14～9.21 mg/g,E-4-O-β-D-葡萄糖酰咖啡酸1.87～3.19 mg/g。该方法更全面地反映了药材的化学成分信息,并能从定性和定量两方面控制骨碎补药材的内在质量。