A human embryonic stem cell-based in vitro model revealed that ultrafine carbon particles may cause skin inflammation and psoriasis

Air pollution has been linked to many health issues,including skin conditions,especially in children.Among all the atmospheric pollutants,ultrafine particles have been deemed very dangerous since they can readily penetrate the lungs and skin,and be absorbed into the bloodstream.Here,we employed a human embryonic stem cell(h ESC)-based differentiation system towards keratinocytes,to test the effects of ultrafine carbon particles,which mimic ambient ultrafine particles,at environment related concentrations.We found that10 ng/mL to 10 μg/mL ultrafine carbon particles down-regulated the expression of the pluripotency marker SOX2 in h ESCs.Moreover,1 μg/mL to 10 μg/mL carbon particle treatments disrupted the keratinocyte differentiation,and up-regulated inflammationand psoriasis-related genes,such as IL-1β,IL-6,CXCL1,CXCL2,CXCL3,CCL20,CXCL8,and S100 A7 and S100 A9,respectively.Overall,our results provide a new insight into the potential developmental toxicity of atmospheric ultrafine particles.     

广州市实施I/M简易瞬态工况检测方法的环境效果分析

采用简易瞬态工况法对在用车进行检测,能够更为有效地筛选高排放车辆.2007—2009年广州市轻型汽油车的简易瞬态工况法的初检数据表明,国Ⅰ排放标准实施以前(简称"国Ⅰ前")车辆和国Ⅰ及以后排放标准车辆排放超限值比例分别为20.1%和17.6%.简易瞬态工况法复检数据得到的国Ⅰ前和国Ⅰ及以后车辆经维护后能够达标的比例分别为76.0%和64.7%,且经过有效维护后超标车辆的平均排放水平有较大比例的削减.同时,采用修正的MOBILE5模型对广州市轻型汽油车排放进行模拟.结果发现,广州市2009年轻型汽油车的CO、HC和NO_x排放量分别为24.4×10⁴、3.8×10⁴和1.8×10⁴ t.如果考虑I/M制度实施及实际执行率,复检不达标车辆在全部淘汰情景下,2009年广州市轻型汽油车排放的CO、HC和NO_x分别能削减4.20×10⁴、0.58×10⁴和0.15×10⁴ t,占全部轻型汽油车的削减比例分别为17.2%、15.3%和8.2%;而在全部置换为国Ⅳ新车情景下,3种污染物分别能削减4.12×10⁴、0.57×10⁴和0.14×10⁴ t,削减比例分别为16.9%、15.0%和8.0%.国Ⅰ前及国Ⅰ车辆对CO和HC削减量的贡献达到90%左右,对NO_x削减量的贡献也在85%左右.     

Characterization of personal exposure concentration of fine particles for adults and children exposed to high ambient concentrations in Beijing, China

In China, the health risk from overexposure to particles is becoming an important public health concern. To investigate daily exposure characteristics to PM 2.5 with high ambient concentration in urban area, a personal exposure study was conducted for school children, and office workers in Beijing, China. For all participants (N = 114), the mean personal 24-hr exposure concentration was 102.5, 14.7, 0.093, 0.528, 0.934, 0.174 and 0.703 μg/m 3 for PM 2.5 , black carbon, Mn, Al, Ca, Pb, and Fe. Children's exposure concentrations of PM 2.5 were 4-5 times higher than those in related studies. The ambient concentration of PM 2.5 (128.5 μg/m 3 ) was significantly higher than the personal exposure concentration (P 0.05), and exceed the reference concentration (25 μg/m 3 ) of WHO air quality guideline. Good correlation relationships and significant differences were identified between ambient concentration and personal exposure concentration. The relationships indicate that the ambient concentration is the main factor influencing personal exposure concentration, but is not a good indicator of personal exposure concentration. Outdoor activities (commute mode, exposure to heating, workday or weekend travel) influenced personal exposure concentrations significantly, but the magnitude of the influence from indoor activities (exposure to cooking) was masked by the high ambient concentrations.     

长江三角洲平原南部上新世以来古环境演变及多重地层划分

对长江三角洲平原BZK01钻孔进行沉积物¹⁴C测年、粒度、磁学、孢粉和微体古生物分析,结合伽玛测井、岩性地层讨论了上新世以来钻孔揭示的孢粉组合、沉积环境演化、沉积相和古气候特征,建立了钻孔的第四纪多重地层划分对比框架。结果表明,受原始地形地貌、海平面变化、海陆变迁、古气候冷暖更替及新构造运动的影响,研究区上新世以来经历了多次环境变化。钻孔自下而上揭示岩性地层依次为基岩长河组、新近纪-第四纪沉积的嘉兴组、前港组、东浦组、宁波组、镇海组,孢粉组合可划分出16个孢粉带,按暖期温暖潮湿-冷期寒冷干燥古气候旋回变化的周期律,BZK01钻孔反映该区域共存在7个古气候旋回。建立的钻孔多重地层划分对比揭示151.9～278.0 m为河流相和河湖相交替沉积的上新世-早更新世时期,存在两个气候旋回过程;83.5～151.9 m为河流相-河湖相-浅湖相沉积环境的中更新世,包含两个气候旋回过程;15.4～83.5 m为晚更新世,沉积环境自下而上为河口相-河湖相-潮坪相-滨海相-河湖相,与王店海侵-杭州海侵时期对应,包括两个气候旋回;0～15.4 m为河口相-河湖相-泻湖相沉积环境的全新世,对应富阳海侵,包括一个气候旋回。     

负载Pt对锐钛矿-板钛矿双相TiO_2光催化性能的影响

采用水热法合成了板钛矿-锐钛矿双相TiO_2,通过浸渍和氢还原法将贵金属Pt负载在双相TiO_2表面制成Pt/双相TiO_2催化剂。TEM表征结果显示:Pt/双相TiO_2催化剂中Pt的晶粒尺寸很小,晶粒尺寸分布较窄;低负载量(质量分数0.2%和2.0%)时,Pt晶粒在TiO_2表面分布非常均匀,Pt负载量达到4.0%时,Pt晶粒在TiO_2表面的分散性变差。光催化活性实验结果表明:负载Pt能显著提高双相TiO_2催化剂的甲基橙降解率;2.0%Pt/双相TiO_2催化剂的光降解性能最佳。光催化活性提高的主要原因是由于Pt颗粒的电子贮存能力促进了光生电子-空穴对的分离。     

冬季燃油节能降耗设备的研制与应用

新疆等西北地区冬季时间长,温度低,由于--35#柴油的价格比0#柴油高,但其燃烧值低于0#柴油,因此考虑用0#柴油代替--35#柴油,以降低钻井成本。回收350℃高温尾气中的热量,进行水罐加热,使水温达到60℃;然后用60℃热水对0#柴油罐进行加热和保温,使油温达到30℃。达到在冬季用0#柴油代替--35#柴油的目的,使尾气回收利用设备不需要另外的能量补给。     

Aqueous photolysis of tetracycline and toxicity of photolytic products to luminescent bacteria

The extensive utilization of antibiotics in the pharmaceutical therapies and agricultural husbandry has led to the worldwide pollution in environments. In this study the photolysis behaviors of tetracycline (TC) and toxicity of its degradation products were investigated. The results showed that TC photolysis followed first-order kinetics. The photolysis rate was found to be dependent on the initial TC concentration and increasing TC concentration from 10 to 40mgl(-1) led to the decrease of the photolysis rate constant from 0.0045min(-1) to 0.0014min(-1). TC photolysis was highly pH-dependent and strongly enhanced at high pH value. Markedly elevated TC photolysis was also observed in the presence of nitrate and dissolved organic matter. Upon irradiation for 300min, only 15% reduction of total organic carbon (TOC) occurred in spite of quick conversion of 73% of TC, suggesting that a majority of TC transformed into intermediate products without complete mineralization. The intermediate products from TC photolysis were analyzed using high-performance liquid chromatography-electrospray ionisation-mass spectrometry (HPLC-ESI-MS) and the main photolysis products of TC were proposed. The toxicity of the photolysis compounds was evaluated using luminescent bacterium, and the results revealed that the toxicity increased with irradiation, indicative of a higher adversity risk of the degradation products of TC on bacteria upon photolysis.     

铝合金偏压构件高温下整体弯扭承载力研究∗

为研究铝合金偏压构件在高温下的整体弯扭稳定承载性能,完成了12根铝合金H型截面构件偏心受压稳定承载力试验,所有试件均发生弯扭失稳。采用ANSYS对试件进行数值模拟,有限元与试验结果在破坏形态和荷载-位移曲线上吻合良好。基于所建立的数值模型,对不同铝合金牌号、截面类型、截面规格和长细比的国产铝合金偏压构件进行了大规模参数分析,共得到532条相关曲线。根据试验和有限元结果,提出铝合金偏压构件高温下的弯扭稳定承载力计算公式,为铝合金偏压构件的抗火设计提供了依据。     

基于FLUENT的废线路板元器件脱焊数值模拟

带元器件的废线路板的手工拆解劳动繁重,在拆解中产生的有害气体损害工人的健康,拆解后的残留物污染环境,因此,废线路板的自动拆解就显得十分必要.针对废线路板上电子元器件自动拆解中焊点的熔焊问题,采用FLUENT计算机软件进行模拟研究,分析了导热介质、初始温度、流体速度对焊点加热熔化效率的影响.结果表明,焊点在初始温度为47...     

铁路货车制造企业焊接烟尘治理探讨

为改善焊接作业环境、保护职工健康,基于某铁路货车企业的生产工艺和焊接烟尘治理难点,从完善焊接烟尘治理技术方案、优化焊接方法和焊接结构、改造厂房加强换气通风等方面总结治理措施,提出了焊接烟尘综合治理的新方向,即融入绿色设计思维、提高工艺制造水平、结合智能制造和采取综合治理方案.