大同市空气中NOx的污染分析及治理

通过对大同市近3年的氮氧化物数据监测，分析了氮氧化物的组成，来源及对人体的危害，并根据大同市的实际情况提出了氮氧化物污染的治理技术。     

B改性钒钛催化剂低温NH3-SCR还原NOx

选择性催化还原(SCR)技术是降低柴油机NOx排放的常用技术,其核心部件为催化剂.目前最广泛使用的催化剂为V2O5/TiO2催化剂,但其存在一些缺点,如低温活性不佳、活性温度窗口较窄等.为了解决该催化剂存在的上述一系列问题,我们对V2O5/TiO2催化剂进行改性处理.采用溶胶-凝胶法和浸渍法制备了 B改性的V2O5/T...     

国内外目前具有研究价值的烟气脱硝技术

随着氮氧化物污染越来越严重,研究并发展更有效、更实用的的烟气脱氮技术越来越迫切。本文主要介绍几种当前多种脱氮技术中比较具有研究价值烟气脱氮技术。这些技术大都是目前已经投入生产使用的技术,但在不同的方面存在很多的不足,若通过进一步的研究与实践,拟补这些不足,将会使目前的烟气脱硝技术进入一个崭新的阶段。     

慢病毒介导的HTRA1突变基因感染对人脑血管平滑肌细胞内氧化应激反应的影响

检测HTRA1及HTRA1-Mut基因慢病毒载体转染HBVSMC后,HBVSMC内氧化应激水平的变化。以HTRA1及HTRA1-Mut基因慢病毒载体转染HBVSMC后,在特定的时间点收集NC、OE-WT HTRA1及OE-MU HTRA1三组细胞的总RNA及总蛋白,分别用RT-PCR和Western Blot的方法检测三组细胞的NOX4 mRNA及蛋白水平的表达情况;用DCFH-DA法检测三组细胞内的活性氧水平。从定量PCR结果可以看出,人脑血管平滑肌细胞中,OE-MU组NOX4基因表达丰度是NC组的2.015倍。从Western blot结果可以看出,在正常的人脑血管平滑肌细胞中NOX4蛋白水平表达较低,而在慢病毒LV-HRTA1及LV-HRTA1-MUT感染后NOX4蛋白表达水平增高。在正常的人脑血管平滑肌细胞中ROS水平表达较低,而在慢病毒LVHRTA1及LV-HRTA1-MUT感染后ROS蛋白表达水平增高,在突变型病毒感染细胞组表现更为明显。说明:1HTRA1突变型基因感染人脑血管平滑肌细胞后,细胞内活性氧产量增加,NOX4 mRNA水平的表达正常细胞升高,但较HTRA1野生型基因无明显差别;NOX4在蛋白水平表达较其他两组均升高;2HTRA1突变型基因感染的人脑血管平滑肌细胞出现增殖减少、迁移活力降低以及凋亡增加可能与细胞内的氧化应激有关,为进一步研究CARASIL发病机制奠定基础。     

Direct meso‐Alkynylation of Metalloporphyrins Through Gold Catalysis for Hemoprotein Engineering

A method was developed for the direct functionalization of metalloporphyrins at the methine protons (meso positions) to yield asymmetric alkynylated derivatives by using gold catalysis and hypervalent iodine reagents. This single‐step procedure was applied to b‐type heme and the product was incorporated into a gas‐sensor heme protein. The terminal alkyne allows fluorophore labeling through copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC). Hemoproteins with this type of engineered cofactor have several potential applications in labeling and imaging technologies. Additionally, the alkyne provides a handle for modulating porphyrin electron density, which affects cofactor redox potential and ligand affinity. This method will be helpful for investigating the chemistry of natural heme proteins and for designing artificial variants with altered properties and reactivities.     

Formation of sulfur surface species on a commercial NO<Subscript>x</Subscript>-storage reduction catalyst

The influence of SO₂ exposure under lean (oxidizing) and rich (reducing) reaction conditions on the storage and oxidation/reduction function of a commercial NO_x storage-reduction catalyst was investigated by temperature-programmed uptake experiments and high temperature XRD. Both the storage capacity and the oxidation/reduction function of the catalyst were deactivated by SO₂ exposure under lean and rich reaction conditions. The deactivation of the storage component, i.e. the loss of the NO_x storage capacity, resulted mainly from the formation of Ba-sulfates accumulating in the bulk phase, which have a high thermal stability (>800°C) and, therefore, cannot be removed under the typical operation conditions of a NSR catalyst. For the oxidation function only a temporarily deactivation during lean reaction conditions was observed. Besides the formation of SO^2- ₄ species on the storage component at the beginning of the SO₂ exposure under rich conditions, an adsorption of SO₂ on the noble metal component was observed resulting in the formation of sulfur deposits. The oxidation of these sulfur species with a subsequent spillover of SO^2- ₄ species to the storage component during lean conditions could accelerate the deactivation of the storage capacity.     

电感耦合等离子体原子发射光谱(ICP-AES)法测定车用尿素水溶液中的8种杂质元素含量

将1g尿素水溶液样品置于烘箱105℃下浓缩,在1 100℃马弗炉中加热灰化;取出冷却,使用盐酸(1+1)溶解灰分。采用Al 237.312nm、Ca 393.366nm、Cr 267.716nm、Cu 324.754nm、Fe 238.204nm、Mg 279.553nm、Ni 231.604nm、Zn 213.856nm作为分析线,建立了使用电感耦合等离子体原子发射光谱(ICP-AES)法测定尿素水溶液中铝、钙、铬、铜、铁、镁、镍和锌8种杂质元素的方法。结果表明,铝、钙、铬、铜、铁、镁、镍和锌的线性范围在0.02~2μg/mL时,校准曲线的线性相关系数均不小于0.999 5;方法中各元素的检出限为0.001~0.010μg/mL。将方法应用于尿素水溶液样品中8种杂质元素的测定,结果的相对标准偏差(RSD,n=7)均小于5.0%,加标回收率为91%~108%。方法可一次性完成对多种元素的测定,准确度、精密度较高,方法简便快速,适用于各级检验机构进行多批次、多项目产品的元素检测。     

可同化有机碳测定方法探讨

研究了以３种不同接种方法测定水中可同化有机碳（ＡＯＣ）,结果显示,混合接种法所测结果较接近实际值,分别接种法结果明显高于实际值,依次接种法可能存在Ｐ１７（荧光假单胞菌,Ｐｓｅｕｄｏｍｏｎａｓ ｆｌｔｏｒｅｓｃｅｎｓ）溶解、释放细胞中有机物所至的ＡＯＣ偏高问题。依次接种法有时存在巴氏消毒不能完全杀灭Ｐ１７,从而干扰ＡＯＣ－ＮＯＸ的测定;混合接种法缩短了实验时间,简化了操作步骤,当１个平皿中Ｐ１７和Ｎ     

In Vivo Investigation of the Ameliorating Effect of Tempol against MIA-Induced Knee Osteoarthritis in Rats: Involvement of TGF-β1/SMAD3/NOX4 Cue

Osteoarthritis (OA) is a complex disease characterized by structural, functional, and metabolic deteriorations of the whole joint and periarticular tissues. In the current study, we aimed to investigate the possible effects of tempol on knee OA induced by the chemical chondrotoxic monosodium iodoacetate (MIA) which closely mimics both the pain and structural changes associated with human OA. Rats were administrated oral tempol (100 mg/kg) one week post-MIA injection (3 mg/50 μL saline) at the right knee joints for 21 consecutive days. Tempol improved motor performance and debilitated the MIA-related radiological and histological alterations. Moreover, it subsided the knee joint swelling. Tempol decreased the cartilage degradation-related biomarkers as matrix metalloproteinase-13, bone alkaline phosphatase (bone ALP), and fibulin-3. The superoxide dismutase mimetic effect of tempol was accompanied by decreased NADPH oxidase 4 (NOX4), inflammatory mediators, nuclear factor-kappa B (NF-κB), over-released transforming growth factor-β1 (TGF-β1). Tempol decreased the expression of chemokine (C-C motif) ligand 2 (CCL2). On the molecular level, tempol reduced the phosphorylated protein levels of p38 mitogen-activated protein kinase (MAPK), and small mother against decapentaplegic 3 homologs (SMAD3). These findings suggest the promising role of tempol in ameliorating MIA-induced knee OA in rats via collateral suppression of the catabolic signaling cascades including TGF-β1/SMAD3/NOX4, and NOX4/p38MAPK/NF-κB and therefore modulation of oxidative stress, catabolic inflammatory cascades, chondrocyte metabolic homeostasis.