Objective This study assesses the impact of smoke-free legislation on the incidence rate for acute myocardial infarction(AMI)and stroke in Shenzhen.Methods Data on ischemic(n=72,945)and hemorrhagic(n=18,659)stroke and...Objective This study assesses the impact of smoke-free legislation on the incidence rate for acute myocardial infarction(AMI)and stroke in Shenzhen.Methods Data on ischemic(n=72,945)and hemorrhagic(n=18,659)stroke and AMI(n=17,431)incidence covering about 12 million people in Shenzhen from 2012 to 2016 were used.Immediate and gradual changes in incidence rates were analyzed using segmented Poisson regression.Results Following the smoke-free legislation,a 9%(95%CI:3%-15%)immediate reduction was observed in AMI incidence,especially in men(8%,95%CI:1%-14%)and in those aged 65 years and older(17%,95%CI:9%-25%).The gradual annual benefits were observed only in hemorrhagic and ischemic stroke incidence,with a 7%(95%CI:2%-11%)and 6%(95%CI:4%-8%)decrease per year,respectively.This health effect extended gradually to the 50-64 age group.In addition,neither the immediate nor gradual decrease in stroke and AMI incidence rates did not show statistical significance among the 35-49 age group(P>0.05).Conclusion Smoke-free legislation was enforced well in Shenzhen,which would generate good experiences for other cities to enact and enforce smoke-free laws.This study also provided more evidence of the health benefits of smoke-free laws on stroke and AMI.展开更多
Objective To analyze the association between exposure to second-hand smoke(SHS) and 23 diseases,categorized into four classifications, among the Chinese population.Methods We searched the literature up to June 30, 202...Objective To analyze the association between exposure to second-hand smoke(SHS) and 23 diseases,categorized into four classifications, among the Chinese population.Methods We searched the literature up to June 30, 2021, and eligible studies were identified according to the PECOS format: Participants and Competitors(Chinese population), Exposure(SHS),Outcomes(Disease or Death), and Study design(Case-control or Cohort).Results In total, 53 studies were selected. The odds ratio(OR) for all types of cancer was 1.79(1.56–2.05), and for individual cancers was 1.92(1.42–2.59) for lung cancer, 1.57(1.40–1.76) for breast cancer, 1.52(1.12–2.05) for bladder cancer, and 1.37(1.08–1.73) for liver cancer. The OR for circulatory system diseases was 1.92(1.29–2.85), with a value of 2.29(1.26–4.159) for stroke. The OR of respiratory system diseases was 1.76(1.13–2.74), with a value of 1.82(1.07–3.11) for childhood asthma. The original ORs were also shown for other diseases. Subgroup analyses were performed for lung and breast cancer. The ORs varied according to time period and were significant during exposure in the household;For lung cancer, the OR was significant in women.Conclusion The effect of SHS exposure in China was similar to that in Western countries, but its definition and characterization require further clarification. Studies on the association between SHS exposure and certain diseases with high incidence rates are insufficient.展开更多
Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the vi...Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the visualization of data based on FDS (Fire Dynamics Simulator) and FED fire dynamic data and volume rendering is further optimized, which can be effectively and quickly applied to virtual fire protection. In addition, a comprehensive smoke hazard assessment model based on FED and FED is established to assess the IHD value of different paths, which represents the safety of different paths, and can be used for evacuation or rescue in virtual training. Taking the case of campus fire drill as an experiment, the research shows the accuracy and effectiveness of smoke assessment based on FDS and FED model. The road force with the highest safety can be selected through the comprehensive model. So the assessment model is proved to be valuable.展开更多
Introduction: The use of biomass for cooking is a very common practice in Africa and Benin, and is associated with exposure to organic pollutants. The aim of this study was to assess carbon monoxide exposure and respi...Introduction: The use of biomass for cooking is a very common practice in Africa and Benin, and is associated with exposure to organic pollutants. The aim of this study was to assess carbon monoxide exposure and respiratory disorders in women at artisanal fish-smoking sites. Methods: This was a cross-sectional study of women fish smokers at two artisanal fish-smoking sites in Benin. Recruitment was exhaustive. An interview using a respiratory questionnaire inspired by the Union questionnaire, spirometry and carbon monoxide (CO) measurement were carried out. Descriptive analysis and comparison of means using Student’s t-test with a threshold of p = 0.05 were performed. Results: The median age of the 81 people surveyed was 40, with an interquartile range (IQT) of [25 to 75]. The median duration of daily exposure to smoke was 6 h IQT [4, 7]. Of those surveyed, 64 (79.01%) were illiterate and 39 (48.24%) had been working for 20 years. CO levels at the start of activity varied from 89 to 145 ppm in one case and from 40 to 89 ppm in the other. Respiratory symptoms were present in 19 (23.46%);18 (22.22%) had mild airway impairment on spirometry. There was a statistically significant decrease between the mean values of peak expiratory flow (PEF), mean expiratory volume in seconds (FEV1) and forced vital capacity (FVC) before and after exposure to smoke. Conclusion: CO levels are high on fish smoking sites and respiratory problems are common. Improved working conditions are important for these women.展开更多
In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investi...In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investigates an experimental laboratory smoke environment using an ammonium chloride smoke agent.The particle size distribution,composition,and mass flow distribution of the smoke were studied.Based on a discrete phase model and a kεturbulence model,a numerical simulation was developed to model the smoke generation and diffusion processes of the smoke agent in a confined space.The temporal and spatial distribution characteristics of the smoke mass concentration,velocity,and temperature in the space after smoke generation were analyzed,and the motion law governing the smoke diffusion throughout the entire space was summarized.Combined with the experimental verification of the smoke environment laboratory,the results showed that the smoke plume changed from fan-shaped to umbrella-shaped during smoke generation,and then continued to spread around.Meanwhile,the mass concentration of smoke in the space decreased from the middle outward;the changes in temperature and velocity were small and stable.In the diffusion stage(after 900 s),the mass concentration of smoke above 0.8 m was relatively uniform across an area of smoke that was 12 m thick.The concentration decreased over time,following a consistent decreasing trend,and the attenuation was negligible in a very short time.Therefore,this system was suitable for conducting experimental research on laser fuzes in a smoke environment.Owing to the stability of the equipment and facilities,the setup could reproduce the same experimental smoke environment by artificially controlling the smoke emission of the smoke agent.Overall,this work provides a theoretical reference for subsequent research efforts regarding the construction of uniform smoke environments and evaluating laser transmission characteristics in smoky environments.展开更多
AIM: To quantify smoking/lung cancer relationships accurately using parametric modelling. METHODS: Using the International Epidemiological Studies on Smoking and Lung Cancer database of all epidemiological studies of ...AIM: To quantify smoking/lung cancer relationships accurately using parametric modelling. METHODS: Using the International Epidemiological Studies on Smoking and Lung Cancer database of all epidemiological studies of 100+ lung cancer cases published before 2000, we analyzed 97 blocks of data for amount smoked, 35 for duration of smoking, and 27 for age started. Pseudo-numbers of cases and controls(or at risk) estimated from RRs by dose level formed the data modelled. We fitted various models relating loge RR to dose(d), including βd, βdY and βloge(1 + Wd),and investigated goodness-of-fit and heterogeneity between studies. RESULTS: The best-fitting models for loge RR were0.833 loge [1 +(8.1c/10)] for cigarettes/d(c), 0.792(y/10)0.74 for years smoked(y) and 0.176 [(70- a)/10]1.44 for age of start(a). Each model fitted well overall, though some blocks misfitted. RRs rose from 3.86 to 22.31 between c = 10 and 50, from 2.21 to 13.54 between y = 10 and 50, and from 3.66 to 8.94 between a = 30 and 12.5. Heterogeneity(P < 0.001) existed by continent for amount, RRs for 50 cigarettes/d being 7.23(Asia), 26.36(North America) and 22.16(Europe). Little heterogeneity was seen for duration of smoking or age started. CONCLUSION: The models describe the dose-relationships well, though may be biased by factors including misclassification of smoking status and dose.展开更多
About millions of people die yearly due to tobacco use.A number that has been estimated byWorld Health Organization will be double in next 15 years.Over the past decade significant progress has been made around thewor...About millions of people die yearly due to tobacco use.A number that has been estimated byWorld Health Organization will be double in next 15 years.Over the past decade significant progress has been made around theworld in controlling involuntary exposure of nonsmokers to the Secondhand smoke(SHS).In some country expanding workplace restriction now protect a majority of working adults,but the home remains the most important exposure setting for children.The BIDI is often called the poor man’s cigarette and is perhaps the cheapest tobacco smoking product in the world.Most often found in India,it is more harmful than cigarette and is one of the major sources for Secondhand smoke.展开更多
AIM:To determine the levels of salivary immunoglobulin classes in Nigerian smokers and non-smokers with periodontitis.METHODS:Sixty-nine individuals were recruited into this study after obtaining informed consent.They...AIM:To determine the levels of salivary immunoglobulin classes in Nigerian smokers and non-smokers with periodontitis.METHODS:Sixty-nine individuals were recruited into this study after obtaining informed consent.They were subdivided into three groups that consisted of 20(aged 46 ± 11 years) cigarette smokers with periodontitis(S+P);24(40 ± 12 years) smokers without periodontitis(S-P);and 25(53 ± 11 years) non-smokers with periodontitis(NS+P).An oral and maxillofacial surgeon used radiographs for periodontal probing for the diagnosis of periodontitis.The smokers included subjects who smoked at least six cigarettes per day and all the periodontitis patients were newly diagnosed.About 5 mL of unstimulated saliva was expectorated by each subject into plain sample bottles.Salivary immunoglobulin levels were estimated using enzyme linked immunosorbent assay.Student's t test was used to deter-mine significant differences between the means.Values of P < 0.05 were regarded as significant.RESULTS:No significant differences were observed in the mean salivary levels of the immunoglobulin classes(IgG,IgA,IgM and IgE) when S+P was compared with S-P.Mean salivary levels of IgA(520.0 ± 155.1 ng/mL vs 670.0 ± 110 ng/mL,P = 0.000) and IgM(644.5 ± 160.0 ng/mL vs 791.4 ± 43.7 ng/mL,P = 0.000) were significantly lower in the S+P compared with NS+P group.Salivary IgA(570.4 ± 145.6 ng/mL vs 670.0 ± 110 ng/mL,P = 0.008) and IgM(703.1 ± 169.3 ng/mL vs 791.4 ± 43.7 ng/mL,P = 0.012) levels were significantly lower in the S-P compared with NS+P group.Only one(5%) periodontal patient had detectable levels of salivary IgE(0.20 IU/mL).Similarly,only one smoker(4.17%) had detectable levels of salivary IgE(0.04 IU/mL) and two non-smokers(9.52%) had detectable levels of IgE(0.24 IU/mL).CONCLUSION:Our study suggests that reduced salivary IgA and IgM levels in smokers with periodontitis could enhance increased susceptibility to periodontitis.展开更多
Objective To determine the extent of secondhand smoke exposure in China, and to explore the potential associated factors. Methods This study was a nationally representative household survey examining secondhand smoke ...Objective To determine the extent of secondhand smoke exposure in China, and to explore the potential associated factors. Methods This study was a nationally representative household survey examining secondhand smoke exposure of non-institutionalized men and women aged 15 and older using a global standardized geographically clustered sample design. A total of 13 354 people completed the individual questionnaire with questions on gender, age, educational level, residence, profession, potential factors associated with secondhand smoke exposure, and workplace smoking policy. The data were used to determine whole population estimates of secondhand smoke exposure. Results Among non-smokers aged 15 years and older, it was estimated that 72.4% (556 million) were exposed to secondhand smoke, with 52.5% (292 million) exposed to secondhand smoke daily. The prevalence of secondhand smoke exposure was 74.1% for men, 71.6% for women, 70.5% for urban populations, and 74.2% for rural populations. The rates were 67.3%, 63.3%, and 72.7% respectively, within the household, indoor workplaces and public places. Secondhand smoke exposure was significantly reduced in workplaces with a smoking ban but not in workplaces with a partial smoking ban. Conclusion Although China has made some progress toward a smoke-free environment there remains a high degree of exposure to secondhand smoke.展开更多
Although several studies confirmed that berberine may attenuate airway inflammation in mice with chronic obstructive pulmonary disease(COPD),its underlying mechanisms were not clear until now.We aimed to establish an ...Although several studies confirmed that berberine may attenuate airway inflammation in mice with chronic obstructive pulmonary disease(COPD),its underlying mechanisms were not clear until now.We aimed to establish an experiment mouse model for COPD and to investigate the effects of berberine on airway inflammation and its possible mechanism in COPD model mice induced by cigarette smoke extract(CSE).Twenty SPF C57BL/6 mice were randomly divided into PBS control group,COPD model group,low-dose berberine group and high-dose berberine group,5 mice in each group.The neutrophils and macrophages were examined by Wright's staining.The levels of inflammatory cytokines TNF-α and IL-6 in bronchoalveolar lavage fluid(BALF)were detennined by enzyme-linked immunosorbent assay.The expression levels of TGF-β1,Smad2 and Smad3 mRNA and proteins in lung tissues were respectively detected by quantitative real-time polymerase chain reaction and Western blotting.It was found that CSE increased the number of inflammation cells in BALF,elevated lung inflammation scores,and enhanced the TGF-β1/Smads signaling activity in mice.High-dose berberine restrained the alterations in the COPD mice induced by CSE.It was concluded that high-dose berberine ameliorated CSE-induced airway inflammation in COPD mice.TGF-β1/Smads signaling pathway might be involved in the mechanism.These findings suggested a therapeutic potential of high-dose berberine on the CSE-induced airway inflammation.展开更多
Traditional fire smoke detection methods mostly rely on manual algorithm extraction and sensor detection;however,these methods are slow and expensive to achieve discrimination.We proposed an improved convolutional neu...Traditional fire smoke detection methods mostly rely on manual algorithm extraction and sensor detection;however,these methods are slow and expensive to achieve discrimination.We proposed an improved convolutional neural network(CNN)to achieve fast analysis.The improved CNN can be used to liberate manpower.The network does not require complicated manual feature extraction to identify forest fire smoke.First,to alleviate the computational pressure and speed up the discrimination efficiency,kernel principal component analysis was performed on the experimental data set.To improve the robustness of the CNN and to avoid overfitting,optimization strategies were applied in multi-convolution kernels and batch normalization to improve loss functions.The experimental analysis shows that the CNN proposed in this study can learn the feature information automatically for smoke images in the early stages of fire automatically with a high recognition rate.As a result,the improved CNN enriches the theory of smoke discrimination in the early stages of a forest fire.展开更多
Smoking is a major risk factor for chronic diseases,it has been estimated that 300 million adults currently smoke in China,and the smoking prevalence in males is as high as 52.9%,with 1million smoking-related deaths y...Smoking is a major risk factor for chronic diseases,it has been estimated that 300 million adults currently smoke in China,and the smoking prevalence in males is as high as 52.9%,with 1million smoking-related deaths yearly.Therefore,smoking is also a huge health burden in China[1].Researchers have suggested an association between diet and smoking status with respect to both food and nutrient intakes.According to such studies,smokers tended to have a poor diet.展开更多
In this study,we prepared a series of tung oil phenolic foams(TPF)by a one-pot method.The FT-IR and 1H NMR spectra confirm the successful Friedel-Crafts grafting of phenol to the long-chain alkyl group in tung oil.Mod...In this study,we prepared a series of tung oil phenolic foams(TPF)by a one-pot method.The FT-IR and 1H NMR spectra confirm the successful Friedel-Crafts grafting of phenol to the long-chain alkyl group in tung oil.Modified TPFs exhibit enhanced mechanical properties,including compressive and flexural strengths of up to 0.278±0.036 MPa and 0.450±0.017 MPa,respectively,which represent increases of 68.75%and 86.72%over those of pure phenolic foam(PF).SEM spectra reveal the TPF microstructure to have uniform hexagonal cell morphology,narrower cell size distribution,and smaller mean cell size,suggesting enhanced mechanical properties.The TPF total smoke release decreased by 74.23%,indicating that the long alkyl chain significantly improves smoke suppression of the combusting foam.However,due to the flammability of the alkyl chains,the TPF limiting oxygen index decreases with increasing tung oil content.Moreover,TPF exhibits reduced thermal stability and high-temperature charring rate,elevated peak and mean heat release rates,and higher total heat release compared with pure PF.Therefore,future research will focus on the use of tung oil modified flame retardant to provide more robust phenolic foams.展开更多
Urban tunnels are generally narrow and fire smoke can hardly diffuse.In the present study,numerical simulation is used to analyze the diffusion of high temperature smoke produced by fire inside a specific tunnel(the K...Urban tunnels are generally narrow and fire smoke can hardly diffuse.In the present study,numerical simulation is used to analyze the diffusion of high temperature smoke produced by fire inside a specific tunnel(the Kaiyuan tunnel).The results are compared with similar data relating to other tests to determine the validity of the numerical method.Moreover,the critical velocity obtained by numerical simulation of 5 MW,20 MW,and 50 MW fires in curved and linear sections of the considered tunnel is compared with the values obtained using empirical formulas.The results show that,for the tunnel ventilation design,it is necessary to consider the fan pressurization at different sections and the fan pressurization should be higher at curved sections than that at linear sections.The safety of personnel escaping under different critical velocity values in the linear section has also been considered.On the basis of our findings,if only relying on natural ventilation,people can escape safely for the case of small fires,whereas for medium and large fires,it is necessary to turn on mechanical ventilation in time(and in order to avoid the danger caused by rapid diffusion of smoke,the timing of mechanical ventilation should be carefully tuned).展开更多
Objective: To evaluate the changes of human heart rate (HR) and heart rate variability (HRV) during and after moxa smoke inhalation and to investigate the effects of moxa smoke on human autonomic nervous system. Metho...Objective: To evaluate the changes of human heart rate (HR) and heart rate variability (HRV) during and after moxa smoke inhalation and to investigate the effects of moxa smoke on human autonomic nervous system. Methods: 24 healthy volunteers were exposed to moxa smoke with their HRV parameters measured before, during and after the moxa smoke inhalation. Results: The healthy volunteers exposed to moxa smoke had significant reductions in HR and also significant changes in HRV parameters. Conclusions: Moxa smoke can improve the autonomic nervous system activity. The inhalation of moxa smoke will induce a depressant effect on human body.展开更多
Summary: To investigate whether the change of E-cadherin (ECD) expression plays a role in the injury and repair of airway epithelial cells (AEC) caused by smoking, porcine AECs were cultured by using an enzyme-dispers...Summary: To investigate whether the change of E-cadherin (ECD) expression plays a role in the injury and repair of airway epithelial cells (AEC) caused by smoking, porcine AECs were cultured by using an enzyme-dispersed method. After exposure of the AECs to cigarette smoke extract (CSE), the ECD expression in the cells was detected by using immunocytochemistry and in situ hybridization. The results showed that ECD was distributed on the plasma membrane at the cell junctions of AECs. After exposure to 20 % CSE, the membranous ECD expression was decreased, the cytoplasmic ECD expression was increased (P<0.01) as the exposure time went on. But the content of ECD mRNA in the AECs did not chang. It suggests that the change of ECD ex- pression is regulated at the posttranslational level and plays a role in the injury and repair of AEC caused by smoking.展开更多
基金supported by the CAMS Innovation Fund for Medical Sciences[CIFMS2016-12M-3-001]the China Medical Board Strengthen Capacity of Study and Application on Burden of Disease in Health Care System of China-Establishment and Development of Chinese Burden of Disease Research and Dissemination Center[15-208]。
文摘Objective This study assesses the impact of smoke-free legislation on the incidence rate for acute myocardial infarction(AMI)and stroke in Shenzhen.Methods Data on ischemic(n=72,945)and hemorrhagic(n=18,659)stroke and AMI(n=17,431)incidence covering about 12 million people in Shenzhen from 2012 to 2016 were used.Immediate and gradual changes in incidence rates were analyzed using segmented Poisson regression.Results Following the smoke-free legislation,a 9%(95%CI:3%-15%)immediate reduction was observed in AMI incidence,especially in men(8%,95%CI:1%-14%)and in those aged 65 years and older(17%,95%CI:9%-25%).The gradual annual benefits were observed only in hemorrhagic and ischemic stroke incidence,with a 7%(95%CI:2%-11%)and 6%(95%CI:4%-8%)decrease per year,respectively.This health effect extended gradually to the 50-64 age group.In addition,neither the immediate nor gradual decrease in stroke and AMI incidence rates did not show statistical significance among the 35-49 age group(P>0.05).Conclusion Smoke-free legislation was enforced well in Shenzhen,which would generate good experiences for other cities to enact and enforce smoke-free laws.This study also provided more evidence of the health benefits of smoke-free laws on stroke and AMI.
基金supported by the Chinese Academy of Medical Sciences(CAMS)Innovation Fund for Medical Sciences(CIFM)[NO.2016-12M-3-001]the China Medical Board“Strengthen Capacity of Study and Application on Burden of Disease in Health Care System of China-Establishment and Development of Chinese Burden of Disease Research and Dissemination Center”[NO.15-208]。
文摘Objective To analyze the association between exposure to second-hand smoke(SHS) and 23 diseases,categorized into four classifications, among the Chinese population.Methods We searched the literature up to June 30, 2021, and eligible studies were identified according to the PECOS format: Participants and Competitors(Chinese population), Exposure(SHS),Outcomes(Disease or Death), and Study design(Case-control or Cohort).Results In total, 53 studies were selected. The odds ratio(OR) for all types of cancer was 1.79(1.56–2.05), and for individual cancers was 1.92(1.42–2.59) for lung cancer, 1.57(1.40–1.76) for breast cancer, 1.52(1.12–2.05) for bladder cancer, and 1.37(1.08–1.73) for liver cancer. The OR for circulatory system diseases was 1.92(1.29–2.85), with a value of 2.29(1.26–4.159) for stroke. The OR of respiratory system diseases was 1.76(1.13–2.74), with a value of 1.82(1.07–3.11) for childhood asthma. The original ORs were also shown for other diseases. Subgroup analyses were performed for lung and breast cancer. The ORs varied according to time period and were significant during exposure in the household;For lung cancer, the OR was significant in women.Conclusion The effect of SHS exposure in China was similar to that in Western countries, but its definition and characterization require further clarification. Studies on the association between SHS exposure and certain diseases with high incidence rates are insufficient.
文摘Smoke is the main cause of fire death. In order to minimize the potential danger of smoke hazard, a rational VR based fire training simulator should fully consider all aspects of smoke hazard. In the simulator, the visualization of data based on FDS (Fire Dynamics Simulator) and FED fire dynamic data and volume rendering is further optimized, which can be effectively and quickly applied to virtual fire protection. In addition, a comprehensive smoke hazard assessment model based on FED and FED is established to assess the IHD value of different paths, which represents the safety of different paths, and can be used for evacuation or rescue in virtual training. Taking the case of campus fire drill as an experiment, the research shows the accuracy and effectiveness of smoke assessment based on FDS and FED model. The road force with the highest safety can be selected through the comprehensive model. So the assessment model is proved to be valuable.
文摘Introduction: The use of biomass for cooking is a very common practice in Africa and Benin, and is associated with exposure to organic pollutants. The aim of this study was to assess carbon monoxide exposure and respiratory disorders in women at artisanal fish-smoking sites. Methods: This was a cross-sectional study of women fish smokers at two artisanal fish-smoking sites in Benin. Recruitment was exhaustive. An interview using a respiratory questionnaire inspired by the Union questionnaire, spirometry and carbon monoxide (CO) measurement were carried out. Descriptive analysis and comparison of means using Student’s t-test with a threshold of p = 0.05 were performed. Results: The median age of the 81 people surveyed was 40, with an interquartile range (IQT) of [25 to 75]. The median duration of daily exposure to smoke was 6 h IQT [4, 7]. Of those surveyed, 64 (79.01%) were illiterate and 39 (48.24%) had been working for 20 years. CO levels at the start of activity varied from 89 to 145 ppm in one case and from 40 to 89 ppm in the other. Respiratory symptoms were present in 19 (23.46%);18 (22.22%) had mild airway impairment on spirometry. There was a statistically significant decrease between the mean values of peak expiratory flow (PEF), mean expiratory volume in seconds (FEV1) and forced vital capacity (FVC) before and after exposure to smoke. Conclusion: CO levels are high on fish smoking sites and respiratory problems are common. Improved working conditions are important for these women.
基金the Central University Special Funding for Basic Scientific Research(Grant No.30918012201)the Foundation of JWKJW Field(Grant 2020-JCJQ-JJ-392)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX20_0315).
文摘In response to the demand for short-range detection of anti-smoke environment interference by laser fuzes,this study proposes a smoke environment simulation of non-uniform continuous point source diffusion and investigates an experimental laboratory smoke environment using an ammonium chloride smoke agent.The particle size distribution,composition,and mass flow distribution of the smoke were studied.Based on a discrete phase model and a kεturbulence model,a numerical simulation was developed to model the smoke generation and diffusion processes of the smoke agent in a confined space.The temporal and spatial distribution characteristics of the smoke mass concentration,velocity,and temperature in the space after smoke generation were analyzed,and the motion law governing the smoke diffusion throughout the entire space was summarized.Combined with the experimental verification of the smoke environment laboratory,the results showed that the smoke plume changed from fan-shaped to umbrella-shaped during smoke generation,and then continued to spread around.Meanwhile,the mass concentration of smoke in the space decreased from the middle outward;the changes in temperature and velocity were small and stable.In the diffusion stage(after 900 s),the mass concentration of smoke above 0.8 m was relatively uniform across an area of smoke that was 12 m thick.The concentration decreased over time,following a consistent decreasing trend,and the attenuation was negligible in a very short time.Therefore,this system was suitable for conducting experimental research on laser fuzes in a smoke environment.Owing to the stability of the equipment and facilities,the setup could reproduce the same experimental smoke environment by artificially controlling the smoke emission of the smoke agent.Overall,this work provides a theoretical reference for subsequent research efforts regarding the construction of uniform smoke environments and evaluating laser transmission characteristics in smoky environments.
文摘AIM: To quantify smoking/lung cancer relationships accurately using parametric modelling. METHODS: Using the International Epidemiological Studies on Smoking and Lung Cancer database of all epidemiological studies of 100+ lung cancer cases published before 2000, we analyzed 97 blocks of data for amount smoked, 35 for duration of smoking, and 27 for age started. Pseudo-numbers of cases and controls(or at risk) estimated from RRs by dose level formed the data modelled. We fitted various models relating loge RR to dose(d), including βd, βdY and βloge(1 + Wd),and investigated goodness-of-fit and heterogeneity between studies. RESULTS: The best-fitting models for loge RR were0.833 loge [1 +(8.1c/10)] for cigarettes/d(c), 0.792(y/10)0.74 for years smoked(y) and 0.176 [(70- a)/10]1.44 for age of start(a). Each model fitted well overall, though some blocks misfitted. RRs rose from 3.86 to 22.31 between c = 10 and 50, from 2.21 to 13.54 between y = 10 and 50, and from 3.66 to 8.94 between a = 30 and 12.5. Heterogeneity(P < 0.001) existed by continent for amount, RRs for 50 cigarettes/d being 7.23(Asia), 26.36(North America) and 22.16(Europe). Little heterogeneity was seen for duration of smoking or age started. CONCLUSION: The models describe the dose-relationships well, though may be biased by factors including misclassification of smoking status and dose.
文摘About millions of people die yearly due to tobacco use.A number that has been estimated byWorld Health Organization will be double in next 15 years.Over the past decade significant progress has been made around theworld in controlling involuntary exposure of nonsmokers to the Secondhand smoke(SHS).In some country expanding workplace restriction now protect a majority of working adults,but the home remains the most important exposure setting for children.The BIDI is often called the poor man’s cigarette and is perhaps the cheapest tobacco smoking product in the world.Most often found in India,it is more harmful than cigarette and is one of the major sources for Secondhand smoke.
文摘AIM:To determine the levels of salivary immunoglobulin classes in Nigerian smokers and non-smokers with periodontitis.METHODS:Sixty-nine individuals were recruited into this study after obtaining informed consent.They were subdivided into three groups that consisted of 20(aged 46 ± 11 years) cigarette smokers with periodontitis(S+P);24(40 ± 12 years) smokers without periodontitis(S-P);and 25(53 ± 11 years) non-smokers with periodontitis(NS+P).An oral and maxillofacial surgeon used radiographs for periodontal probing for the diagnosis of periodontitis.The smokers included subjects who smoked at least six cigarettes per day and all the periodontitis patients were newly diagnosed.About 5 mL of unstimulated saliva was expectorated by each subject into plain sample bottles.Salivary immunoglobulin levels were estimated using enzyme linked immunosorbent assay.Student's t test was used to deter-mine significant differences between the means.Values of P < 0.05 were regarded as significant.RESULTS:No significant differences were observed in the mean salivary levels of the immunoglobulin classes(IgG,IgA,IgM and IgE) when S+P was compared with S-P.Mean salivary levels of IgA(520.0 ± 155.1 ng/mL vs 670.0 ± 110 ng/mL,P = 0.000) and IgM(644.5 ± 160.0 ng/mL vs 791.4 ± 43.7 ng/mL,P = 0.000) were significantly lower in the S+P compared with NS+P group.Salivary IgA(570.4 ± 145.6 ng/mL vs 670.0 ± 110 ng/mL,P = 0.008) and IgM(703.1 ± 169.3 ng/mL vs 791.4 ± 43.7 ng/mL,P = 0.012) levels were significantly lower in the S-P compared with NS+P group.Only one(5%) periodontal patient had detectable levels of salivary IgE(0.20 IU/mL).Similarly,only one smoker(4.17%) had detectable levels of salivary IgE(0.04 IU/mL) and two non-smokers(9.52%) had detectable levels of IgE(0.24 IU/mL).CONCLUSION:Our study suggests that reduced salivary IgA and IgM levels in smokers with periodontitis could enhance increased susceptibility to periodontitis.
基金supported by Bloomberg Initiative to Reduce Tobacco Use, the Bill and Melinda Gates Foundation the Centers for Disease Control Foundation and World Health Organization (WHO).Project No:HQTFI081955
文摘Objective To determine the extent of secondhand smoke exposure in China, and to explore the potential associated factors. Methods This study was a nationally representative household survey examining secondhand smoke exposure of non-institutionalized men and women aged 15 and older using a global standardized geographically clustered sample design. A total of 13 354 people completed the individual questionnaire with questions on gender, age, educational level, residence, profession, potential factors associated with secondhand smoke exposure, and workplace smoking policy. The data were used to determine whole population estimates of secondhand smoke exposure. Results Among non-smokers aged 15 years and older, it was estimated that 72.4% (556 million) were exposed to secondhand smoke, with 52.5% (292 million) exposed to secondhand smoke daily. The prevalence of secondhand smoke exposure was 74.1% for men, 71.6% for women, 70.5% for urban populations, and 74.2% for rural populations. The rates were 67.3%, 63.3%, and 72.7% respectively, within the household, indoor workplaces and public places. Secondhand smoke exposure was significantly reduced in workplaces with a smoking ban but not in workplaces with a partial smoking ban. Conclusion Although China has made some progress toward a smoke-free environment there remains a high degree of exposure to secondhand smoke.
基金This work was supported by the National Natural Science Foundation of China(No.81400008).
文摘Although several studies confirmed that berberine may attenuate airway inflammation in mice with chronic obstructive pulmonary disease(COPD),its underlying mechanisms were not clear until now.We aimed to establish an experiment mouse model for COPD and to investigate the effects of berberine on airway inflammation and its possible mechanism in COPD model mice induced by cigarette smoke extract(CSE).Twenty SPF C57BL/6 mice were randomly divided into PBS control group,COPD model group,low-dose berberine group and high-dose berberine group,5 mice in each group.The neutrophils and macrophages were examined by Wright's staining.The levels of inflammatory cytokines TNF-α and IL-6 in bronchoalveolar lavage fluid(BALF)were detennined by enzyme-linked immunosorbent assay.The expression levels of TGF-β1,Smad2 and Smad3 mRNA and proteins in lung tissues were respectively detected by quantitative real-time polymerase chain reaction and Western blotting.It was found that CSE increased the number of inflammation cells in BALF,elevated lung inflammation scores,and enhanced the TGF-β1/Smads signaling activity in mice.High-dose berberine restrained the alterations in the COPD mice induced by CSE.It was concluded that high-dose berberine ameliorated CSE-induced airway inflammation in COPD mice.TGF-β1/Smads signaling pathway might be involved in the mechanism.These findings suggested a therapeutic potential of high-dose berberine on the CSE-induced airway inflammation.
基金National Natural Science Foundation of China(31670717)Natural Science Foundation of Heilongjiang Province(LH2020C051)。
文摘Traditional fire smoke detection methods mostly rely on manual algorithm extraction and sensor detection;however,these methods are slow and expensive to achieve discrimination.We proposed an improved convolutional neural network(CNN)to achieve fast analysis.The improved CNN can be used to liberate manpower.The network does not require complicated manual feature extraction to identify forest fire smoke.First,to alleviate the computational pressure and speed up the discrimination efficiency,kernel principal component analysis was performed on the experimental data set.To improve the robustness of the CNN and to avoid overfitting,optimization strategies were applied in multi-convolution kernels and batch normalization to improve loss functions.The experimental analysis shows that the CNN proposed in this study can learn the feature information automatically for smoke images in the early stages of fire automatically with a high recognition rate.As a result,the improved CNN enriches the theory of smoke discrimination in the early stages of a forest fire.
基金supported by the National Nature Science Foundation of China [No.81602851]Excellent Young Talents of Health System in Shanghai [No.2017YQ043]
文摘Smoking is a major risk factor for chronic diseases,it has been estimated that 300 million adults currently smoke in China,and the smoking prevalence in males is as high as 52.9%,with 1million smoking-related deaths yearly.Therefore,smoking is also a huge health burden in China[1].Researchers have suggested an association between diet and smoking status with respect to both food and nutrient intakes.According to such studies,smokers tended to have a poor diet.
基金the financial support from the Fundamental Research Funds for the Central Non-profit Research Institution of CAF(No.CAFYBB2018MA001)the National Natural Science Foundation of China(Grant No.31700499).
文摘In this study,we prepared a series of tung oil phenolic foams(TPF)by a one-pot method.The FT-IR and 1H NMR spectra confirm the successful Friedel-Crafts grafting of phenol to the long-chain alkyl group in tung oil.Modified TPFs exhibit enhanced mechanical properties,including compressive and flexural strengths of up to 0.278±0.036 MPa and 0.450±0.017 MPa,respectively,which represent increases of 68.75%and 86.72%over those of pure phenolic foam(PF).SEM spectra reveal the TPF microstructure to have uniform hexagonal cell morphology,narrower cell size distribution,and smaller mean cell size,suggesting enhanced mechanical properties.The TPF total smoke release decreased by 74.23%,indicating that the long alkyl chain significantly improves smoke suppression of the combusting foam.However,due to the flammability of the alkyl chains,the TPF limiting oxygen index decreases with increasing tung oil content.Moreover,TPF exhibits reduced thermal stability and high-temperature charring rate,elevated peak and mean heat release rates,and higher total heat release compared with pure PF.Therefore,future research will focus on the use of tung oil modified flame retardant to provide more robust phenolic foams.
基金supported by the National Natural Science Foundation of China(Grant No.11372166).
文摘Urban tunnels are generally narrow and fire smoke can hardly diffuse.In the present study,numerical simulation is used to analyze the diffusion of high temperature smoke produced by fire inside a specific tunnel(the Kaiyuan tunnel).The results are compared with similar data relating to other tests to determine the validity of the numerical method.Moreover,the critical velocity obtained by numerical simulation of 5 MW,20 MW,and 50 MW fires in curved and linear sections of the considered tunnel is compared with the values obtained using empirical formulas.The results show that,for the tunnel ventilation design,it is necessary to consider the fan pressurization at different sections and the fan pressurization should be higher at curved sections than that at linear sections.The safety of personnel escaping under different critical velocity values in the linear section has also been considered.On the basis of our findings,if only relying on natural ventilation,people can escape safely for the case of small fires,whereas for medium and large fires,it is necessary to turn on mechanical ventilation in time(and in order to avoid the danger caused by rapid diffusion of smoke,the timing of mechanical ventilation should be carefully tuned).
文摘Objective: To evaluate the changes of human heart rate (HR) and heart rate variability (HRV) during and after moxa smoke inhalation and to investigate the effects of moxa smoke on human autonomic nervous system. Methods: 24 healthy volunteers were exposed to moxa smoke with their HRV parameters measured before, during and after the moxa smoke inhalation. Results: The healthy volunteers exposed to moxa smoke had significant reductions in HR and also significant changes in HRV parameters. Conclusions: Moxa smoke can improve the autonomic nervous system activity. The inhalation of moxa smoke will induce a depressant effect on human body.
基金This project was supported by a grant from National Natural Science Foundation of China !(39570288).
文摘Summary: To investigate whether the change of E-cadherin (ECD) expression plays a role in the injury and repair of airway epithelial cells (AEC) caused by smoking, porcine AECs were cultured by using an enzyme-dispersed method. After exposure of the AECs to cigarette smoke extract (CSE), the ECD expression in the cells was detected by using immunocytochemistry and in situ hybridization. The results showed that ECD was distributed on the plasma membrane at the cell junctions of AECs. After exposure to 20 % CSE, the membranous ECD expression was decreased, the cytoplasmic ECD expression was increased (P<0.01) as the exposure time went on. But the content of ECD mRNA in the AECs did not chang. It suggests that the change of ECD ex- pression is regulated at the posttranslational level and plays a role in the injury and repair of AEC caused by smoking.
