Genotoxicity and Reduced Heat Shock Protein 70 in Human Airway Smooth Muscle Cells Exposed to Cigarette Smoke Extract

Cigarette smoke is associated with the development of several diseases, such as chronic ob- structive pulmonary disease （COPD）. The purpose of this study was to investigate genotoxicity and heat shock protein 70 （Hsp70） in human airway smooth muscle cells （HASMCs） exposed to cigarette smoke extract （CSE）. HASMCs was exposed to CSE with different doses for 24 h. The level of 8-hydroxydeoxyguanosine （8-OHdG） was determined by using HPLC-ECD, the DNA damage was ana- lyzed by using comet assay, and apoptosis was examined by using Annexin-FITC/PI staining. The pro- duction of Hsp70 after CSE stimulation was tested. Results indicated that CSE significantly increased the level of 8-OHdG, DNA damage and cell apoptosis, and reduced the production of Hsp70. In par- ticular, levels of Hsp70 were inversely correlated with 8-OHdG, DNA damage and cell apoptosis. It was concluded that cigarette smoke induced genotoxicity and decreased the production of cell protective protein Hsp70, which may contribute to the development of some airway diseases.

Assessment of tobacco heating system 2.4 on osteogenic differentiation of mesenchymal stem cells and primary human osteoblasts compared to conventional cigarettes

BACKGROUND Cigarette smoking(CS)is the most common method of consuming tobacco.Deleterious effects on bone integrity,increased incidence of fractures,and delayed fracture healing are all associated with CS.Over 150 of the 6500 molecular species contained in cigarette smoke and identified as toxic compounds are inhaled by CS and,via the bloodstream,reach the skeletal system.New technologies designed to develop a reduced-risk alternative for smokers are based on electronic nicotine delivery systems,such as e-cigarettes and tobacco heating systems(THS).THS are designed to heat tobacco instead of burning it,thereby reducing the levels of harmful toxic compounds released.AIM To examine the effects of THS on osteoprogenitor cell viability and function compared to conventional CS.METHODS Human immortalized mesenchymal stem cells(n=3)and primary human preosteoblasts isolated from cancellous bone samples from BG Unfall Klinik Tübingen(n=5)were osteogenically differentiated in vitro with aqueous extracts generated from either the THS 2.4“IQOS”or conventional“Marlboro”cigarettes for up to 21 d.Cell viability was analyzed using resazurin conversion assay(mitochondrial activity)and calcein-AM staining(esterase activity).Osteogenic differentiation and bone cell function were evaluated using alkaline phosphatase(AP)activity,while matrix formation was analyzed through alizarin red staining.Primary cilia structure was examined by acetylatedα-tubulin immunofluorescent staining.Free radical production was evaluated with 2’,7’-dichlorofluoresceindiacetate assay.RESULTS Our data clearly show that THS is significantly less toxic to bone cells than CS when analyzed by mitochondrial and esterase activity(P<0.001).No significant differences in cytotoxicity between the diverse flavors of THS were observed.Harmful effects from THS on bone cell function were observed only at very high,non-physiological concentrations.In contrast,extracts from conventional cigarettes significantly reduced the AP activity(by two-fold)and matrix mineralization(four-fold)at low concentrations.Additionally,morphologic analysis of primary cilia revealed no significant changes in the length of the organelle involved in osteogenesis of osteoprogenitor cells,nor in the number of ciliated cells following THS treatment.Assessment of free radical production demonstrated that THS induced significantly less oxidative stress than conventional CS in osteoprogenitor cells.CONCLUSIONTHS was significantly less harmful to osteoprogenitor cells during osteogenesisthan conventional CS. Additional studies are required to confirm whether THS isa better alternative for smokers to improve delays in bone healing followingfracture.

Effects of Different Ceilings in a Burning Compartment on Smoke Hazard with Single Heat Action Analysis Added

One quarter scale experiment device of a typical L-shape architecture structure including a burning room and an adjacent hallway is established to carry out the research.The smoke characteristics at the sampling points below the ceiling of the burning compartment and the roof of the hallway are studied systematically to find out the effects of different ceilings on the local fire origin compartment and the smoke transportation to a remote area.A series of tests is reported and the smoke residence time,the concentration peak and the concentration build up rate are investigated as functions of the type of the ceiling.The smoke residence time,the most important factor concerning smoke toxicity,is described by a novel concept,wavelength,in this study.Furthermore,it is worth emphasizing that the PVC ceiling exhibits a phenomenon of frequent collapse during the fire developing period.The single heat action is conducted to judge the smoke and the heat effect on the fire risk.

Study of the Influence of the Distance between Smoke Outlets and Fire Source on Smoke Flow Characteristics in Tunnel Fires

This paper explores the smoke flow characteristics in tunnel fires,giving a particular emphasis on the effects of different distances between the smoke outlets and the fire source.It examines the smoke behavior under different conditions,including variations in heat release rates,exhaust volumetric flow rates,spacing between smoke outlets,and the longitudinal fire source positions.Results indicate that altering the fire source positions and the smoke outlets in the tunnel leads to variations in the properties of smoke flow both the fire source upstream and downstream;the distance between fire source and smoke outlet increases gradually,airflow rate decreases initially and eventually reaches a stable state.Similarly,smoke mass flow rate exhibits an increasing trend that eventually reaches a stable state.Moreover,the heat exchange between the tunnel walls and hot smoke increases as the smoke outlet moves further away from the fire source.This interaction leads to a reduction in the heat exhaust coefficient and a decrease in the distance the smoke spreads.This study investigates the impact of altering the relative longitudinal fire source positions and smoke outlet on smoke flow characteristics by numerical simulation.A theoretical analytical method is used to give a predictive model for the heat exhaust coefficient and the smoke spreading distance.This research can support the theory and technical process of tunnel smoke exhaust prevention and control.

Heat Shock Protein 70 Gene Polymorphisms in Han Nationality of China with Chronic Obstructive Pulmonary Diseases

In order to investigate whether polymorphism in gene for heat shock protein 70 (HSP70) has any bearing on individual susceptibility to the development of chronic obstructive pulmonary disease(COPD), the geotypes of 88 patients with COPD and 87 healthy smoking control subjects were tested by polymerase chain reaction followed by restriction fragment polymorphism analysis for HSP70 gene. In COPD group, HSP70 1 genotype A/A, A/B and B/B was 59.1 %, 35.2 % and 5.7 %, HSP70 2 genotype A/A, A/B and B/B was 26.1 %, 54.6 % and 19.3 %, and HSP70 hom genotype A/A, A/B and B/B was 70.4 %, 27.3 % and 2.3 % respectively. In the control group, it was 60.9 %, 27.5 % and 3.5 %, 20.7 %, 56.3 % and 23.0 %, and 54.0 %, 42.5 % and 3.5 %, respectively. The frequency of polymorphic genetypes showed no difference between the COPD group and the control group ( P >0.05). It was suggested that geneic polymorphism in HSP70 is not associated with development of COPD in Han nationality of China.

Expression of Heat Stress Protein 70 mRNA in Patients with Chronic Obstructive Pulmonary Disease and Its Significance

The effects of cigarette smoke extract (CSE) on the expression of heat stress protein 70 (Hsp70) in human bronchi smooth muscle cells were investigated in vitro, and the changes in Hsp70 mRNA in the patients with chronic obstructive pulmonary disease and their significance were explored. Human bronchi smooth muscle cells were cultured with CSE at the different concentrations. The expression of Hsp70 mRNA and Hsp70 was detected by reverse translation-polymerase chain reaction (RT-PCR) and Western blotting respectively. Levels of Hsp70 mRNA and Hsp70 in lymphocytes from 20 patients with COPD and 20 healthy smoking control subjects were measured by RT-PCR and Western blotting. The results showed the expression of both Hsp70 mRNA and Hsp70 was decreased conformably in human bronchi smooth muscle cells treated with CSE at certain concentration in vitro. The A values of the Hsp70 mRNA expression were 0.24±0.11 and 0.42±0.13 respectively in COPD patients and healthy smoking controls with the difference being significant (P<0.01). There was also significant difference in the A values of the Hsp70 expression between COPD patients and healthy smoking controls (20.9±9.9 vs 44.8±15.3, P<0.01). The levels of Hsp70 mRNA had strongly positive correlation with Hsp70 protein (r = 0.85, P<0 01). It was suggested that the expression of Hsp70 mRNA was in concordance with the expression of Hsp70, which could provide a basis on the study of Hsp70 gene regulation and Hsp70 gene in the development of COPD.

基于WRF-SMOKE-CMAQ模型的济南市清洁取暖改造环境效益评估

为评估济南市清洁取暖改造后的环境效益,以2018年为基准年,采用WRF-SMOKE-CMAQ模型模拟计算了2019—2021年济南市冬季清洁取暖改造后各项污染物改善率,并分析了不同污染时段和不同气象条件下污染物的改善率。结果表明:济南市清洁取暖改造后各污染物浓度均有不同程度的改善,其中CO、SO_(2)和细颗粒物(PM_(2.5))基准年改善率(模拟的污染物浓度相对于基准年同时段的改善率)较大,主要与散煤燃烧CO、SO_(2)和PM_(2.5)的排放因子较大有关,2020年年均改善率(模拟的污染物浓度相对于去年同时段的改善率)最大,主要与污染物的减排量最多有关;各污染物改善呈现出明显的区域差异,清洁取暖改造户数较多的区县污染物年均改善率较高;各污染物在空气严重污染时段基准年改善率均最大,重度污染时段次之,并且在不利气象条件时基准年改善率也最大,说明清洁取暖改造对冬季不利气象条件造成的高污染物浓度起到明显的削峰作用,可为济南市空气质量持续改善提供有力保障。

用于加热卷烟的石蜡改性二醋酸纤维素降温滤嘴的制备与表征

以二醋酸纤维素滤棒为载体,以食品级石蜡为相变吸热材料,采用浸渍法制备了石蜡/醋纤降温滤棒,研究了石蜡熔点和负载量对加热卷烟主流烟气温度的影响,并采用热重/差热分析仪(TG/DTA)、傅里叶变换红外光谱仪(FT-IR)、差示扫描量热仪(DSC)和场发射扫描电子显微镜(SEM)等技术对石蜡/醋纤滤棒进行了表征。石蜡/醋纤滤棒是通过醋纤滤棒的吸附作用完成复合,在抽吸过程中具有良好的热稳定性,当52~#石蜡乳化液质量分数为60%时,即石蜡负载量为35 mg时,由石蜡/醋纤滤棒组成的三段式降温滤嘴对主流烟气具有显著的降温效果,可将主流烟气温度从68℃降低到42℃。

某核电厂电气仪控房间火灾排烟温度分析

对某核电厂电气厂房的2个电气仪控房间进行了火灾排烟温度模拟分析。模拟计算了排烟系统不同时刻启动时,这2个防火空间室内空气温度的变化情况。结果表明:排烟系统启动后房间空气温度迅速降低,然后逐渐升高,最后随着火灾热释放速率的降低而逐渐降低;对于手动启动的排烟系统,需及时启动才能有效排除火灾中的烟气;需合理设置排烟防火阀,以保护排烟风机等。

侧部双点排烟模式排热效率研究

为探究隧道火灾侧部排烟口排热效率的表达公式,采用理论分析推导出排热效率与火灾热释放速率、排烟风速、排烟口距地面高度、排烟口间距4个影响参数的量纲一关系式,通过FDS数值模拟研究不同因素影响下的烟流特征并对数据进行拟合,确定了排热效率与这4个影响参数的关系。结果表明,在侧部双点排烟模式下,排热效率随火灾热释放速率增大呈-0.33次方减小关系,与排烟口排烟风速呈0.23次方增长关系,与排烟口距地面高度呈1.25次方增长关系,与排烟口间距呈-0.57次方减小关系,最终通过线性拟合建立了考虑吸穿影响的侧部双点排烟模式下排烟口处排热效率的模型。研究结果可为隧道侧部排烟系统的设计提供参考。

典型电加热卷烟与传统卷烟烟气粒相成分比较研究

【背景和目的】加热卷烟具有烟草的感官特征,但由于受热方式不同,香气风格特征与传统卷烟存在较大区别。为明确加热卷烟烟气组成特征,开展代表性产品烟气成分对比研究。【方法】通过在线液相色谱-气相色谱/质谱联用系统对代表性的传统卷烟及加热卷烟产品进行烟气成分分析。【结果】(1)4种加热卷烟烟气成分种类和含量均低于传统卷烟。(2)4种不同类型加热卷烟产品烟气组成差异不大,但HTP-1烟气组分特征接近于混合型卷烟。(3)加热卷烟烟气特征香气成分包括大马酮、羟基丙酮、糠醇、γ-丁内酯、β-石竹烯、植醇、芳樟醇等,体现了加热卷烟烟草本香、烘焙、烤甜香的典型风格特征。【结论】4种代表性的加热卷烟烟气组成总体上属于传统卷烟烟气组成的子集,同时具有自身的特征。烟气组成是影响加热卷烟和传统卷烟烟气风格特征差异的主要原因。

隧道流淌火发展蔓延规律的研究现状及未来展望

在隧道环境中,流淌火的火焰分叉融合、振荡和倾斜等燃烧行为,扩散油层的流动及其与隧道底壁面、火焰烟气的热传递过程具有复杂性和非稳定性。这会加剧引燃周围其他可燃物的危险性,给人们的生命财产安全带来严重威胁。通过对开放空间与隧道环境中溢油流淌火的扩散与燃烧行为、火焰高度、火焰振荡、火焰热辐射模型、热传递机制、烟气蔓延过程以及顶棚温升模型等的对比分析,指出未来应该进一步深入研究流淌火火焰振荡以及火焰热辐射模型等火焰行为,揭示流淌火蔓延的热传递机制、非稳态燃烧和烟气蔓延动力学规律,为隧道流淌火的防治和应急救援提供理论和技术支持。

卷烟加热棒测温仪的设计和不确定度分析

针对烟草行业,目前尚未存在检测加热卷烟烟具加热温度及温度均匀性的检测装置和方法,为了解决在狭隘空间内对微型棒状加热片的测温需求,本文研制了一种卷烟加热棒测温仪,并设计了一种适用于卷烟加热棒测温的新型结构。为了验证卷烟加热棒测温仪测量结果的准确性与可靠性,对测温仪进行不确定度分析。分析结果依据《GB/T 13283-2008工业过程测量和控制用检测仪表和显示仪表精确度等级》标准,在量程为100℃~400℃,满足0.1级要求。最后实验验证可以有效测量不同烟支的加热温度场情况。

焦化厂烟气脱硫脱硝及余热利用方法研究

焦化厂生产中产生的烟气含有大量的污染物,一旦排放到大气中,会造成严重的环境污染。因此,需要结合实际情况,引进科学合理的烟气脱硫脱硝技术,减少硫化物、NOx污染排放问题,并优化余热回收利用效率,减少资源浪费,促进焦化厂经营效益的提升。基于此,主要对焦化厂烟气脱硫脱硝技术应用以及余热回收利用方法进行探究,旨在进一步提高焦化厂脱硫脱硝效果,减少污染排放,真正实现节能减排和环保目标,促进焦化厂环保技改工作的顺利进行。

熵权-优劣解距离法综合评价油田加热炉能耗方法研究

为了提高油田加热炉运行效果,实现节能减排的目标,采用熵权法结合优劣解距离法对能耗水平进行评价分析。对K油田35台加热炉的空气系数、排烟温度、炉体表面温差、热效率4项指标进行分析,评价加热炉与理想工况的相对接近度,得出加热炉运行的整体情况,并对低效加热炉采取措施。研究表明,3台加热炉的相对接近度明显较低,主要原因是4项指标的综合作用导致,因此对35台加热炉进行综合调整,调整后的加热炉平均热效率由84.22%上升到87.32%,提高了3.68%,累计节约天然气44.97×10^(4)m^(3),折合经济效益157.4万元。

地下电动汽车库的消防排烟设计探讨

目前国家、行业均未对电动汽车库火灾时的消防、排烟制定相关设计规范或技术措施,因而对于电动汽车库的消防排烟系统设计存在较多的争议。本文通过总结大量国家及地方标准,在前人研究的基础上,结合国内外实验数据,选取典型模型进行计算,提出了可供参考的地下电动汽车库的消防排烟设计方法,为地下电动汽车库的消防安全设计积累经验。

船舶机舱火灾热烟分布特性仿真及安全评估

机舱是船舶输出动力的关键舱室,同时也是火灾危险源集中分布的火灾事故高发区。为了评估某船机舱区域的火灾事故特性,针对该船发电机舱开展了油池火典型火灾场景的大涡模拟仿真,并使用烟气温度、辐射热通量两项指标对火灾发生后的机舱环境进行了安全评估。结果显示:火灾发生后机舱内平台甲板下方烟气温度可快速升至200℃以上;火灾发生后74 s,舱内部分电子设备出现永久性损伤;火灾发生后180 s左右,对于消防人员与机舱设备而言机舱处于危险状态,同时舱内绝大部分电子设备发生永久性损伤。本研究结果对船舶机舱设计与消防策略制定具有指导意义。

电动自行车库的排烟计算探讨

目前,我国没有关于电动自行车库排烟规定的国家标准,各地方标准仅作了定性的规定或部分定量的指标要求。通过对几种类型电动自行车进行火灾试验,确定了其火灾热释放速率,为电动自行车库性能化排烟计算提供了依据,并对某实际项目案例进行了分析计算。

一电厂消除脱硫系统白烟技术经济比较

为了消除燃煤电站烟囱的白烟现象,按照烟气直接加热和烟气先冷凝再加热两种方案针对一工程进行了烟囱消除白烟的初步工程方案设计,并进行了烟囱消除白烟的技术经济比较和分析。结果表明,烟气先冷凝再加热的消除烟囱白烟的方案具有明显的技术经济优势。

轧钢加热炉烟气循环超低氮排放改造应用实践

以新兴铸管轧钢加热炉低氮燃烧超低排放改造为例,介绍了轧钢加热炉“炉内烟气循环+分级燃烧+精细调试”低氮燃烧技术及其应用实践。生产实践表明,应用该技术后,从排放源头降低NO_(x)产生,实现了稳定满足国家和地方环保标准限值的目标,并取得良好的环保成效和经济效益,为钢铁行业超低排放提供一种可行可靠的技术参考和工艺借鉴。