Background: Neonatal morbidity and mortality is one of the most public health problems in the world. A lot of neonatal deaths occur in foetus with low birth weight (LBW). Several risk factors of LBW have been describe...Background: Neonatal morbidity and mortality is one of the most public health problems in the world. A lot of neonatal deaths occur in foetus with low birth weight (LBW). Several risk factors of LBW have been described in the literature such as maternal age, chronic and gestational hypertension infection and anémia. Smoking is one of the most important preventable risk factor of LBW in developed and developing countries. Aims: In this study, we evaluated the incidence and the impact of passive smoking and some other principle risk factors of LBW. Material & Methods: This case control study was conducted in the department of obstetrics and gynecology of Marrakesh university hospital in Morocco. During a period of 3 years, all LBW babies were included in the study. Data analysis was performed by SPSS software. The association between LBW and each variable was studied by the chi square test comparing cases and controls groups. Logistic regression analysis was performed after including all variables found to have significant differences on univariate analysis. Results: 288 cases of LBW have been identified representing 2.19% of all births. The study of the categories showed that 84.3% of babies were moderate LBW (1500 - 2500 g), including 49 babies from twin pregnancies. 15.7% were very LBW (<1500 g). Several risk factors have been identified in LBW. Passive smoking was significantly associated with LBW [(OR 1.77;CI: 1.22 - 2.25)]. Conclusion: A number of risk factors are related to low birth weight, which is one of the main predictors of infant mortality. This study shows that passive smoking is one of those risk factors and it is a preventable one.展开更多
To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a nov...To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an adhesive.This porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke suppression.The specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at 624.The FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire resistance.Mechanism analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of FRS-EPS.This novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.展开更多
该文采用动态低频振幅(dynamic amplitude of low frequency fluctuation,dALFF)方法探究青少年吸烟成瘾者脑功能网络的异常,为理解青少年吸烟成瘾的机制提供新视角。通过独立成分分析、滑动窗口法、K-means聚类方法分析青少年吸烟成瘾...该文采用动态低频振幅(dynamic amplitude of low frequency fluctuation,dALFF)方法探究青少年吸烟成瘾者脑功能网络的异常,为理解青少年吸烟成瘾的机制提供新视角。通过独立成分分析、滑动窗口法、K-means聚类方法分析青少年吸烟成瘾者在默认模式网络(default mode network,DMN)、左侧执行控制网络(left executive control network,LECN)、右侧执行控制网络(right executive control network,RECN)和突显网络(salience network,SAN)的动态低频振幅(dALFF)异常。同时,使用皮尔逊相关性分析评估动态指标(时间分数和平均停留时间)与吸烟统计学数据(FTND,烟龄,包年)的关系。相较于青少年健康非吸烟者,青少年吸烟成瘾者在默认模式网络(DMN)、左侧执行控制网络(LECN)、右侧执行控制网络(RECN)和突显网络(SAN)的激活程度降低,皮尔逊相关性分析表明dALFF在状态2时的平均停留时间和包年呈显著正相关。吸烟成瘾会导致青少年的部分脑功能网络异常,其激活程度会降低,同时这些脑区的功能异常与吸烟者的包年存在关联。展开更多
文摘Background: Neonatal morbidity and mortality is one of the most public health problems in the world. A lot of neonatal deaths occur in foetus with low birth weight (LBW). Several risk factors of LBW have been described in the literature such as maternal age, chronic and gestational hypertension infection and anémia. Smoking is one of the most important preventable risk factor of LBW in developed and developing countries. Aims: In this study, we evaluated the incidence and the impact of passive smoking and some other principle risk factors of LBW. Material & Methods: This case control study was conducted in the department of obstetrics and gynecology of Marrakesh university hospital in Morocco. During a period of 3 years, all LBW babies were included in the study. Data analysis was performed by SPSS software. The association between LBW and each variable was studied by the chi square test comparing cases and controls groups. Logistic regression analysis was performed after including all variables found to have significant differences on univariate analysis. Results: 288 cases of LBW have been identified representing 2.19% of all births. The study of the categories showed that 84.3% of babies were moderate LBW (1500 - 2500 g), including 49 babies from twin pregnancies. 15.7% were very LBW (<1500 g). Several risk factors have been identified in LBW. Passive smoking was significantly associated with LBW [(OR 1.77;CI: 1.22 - 2.25)]. Conclusion: A number of risk factors are related to low birth weight, which is one of the main predictors of infant mortality. This study shows that passive smoking is one of those risk factors and it is a preventable one.
基金financially supported by the National Natural Science Foundation of China(51827803,51320105011,51790504,and 51721091)the Young Elite Scientists Sponsorship Program by CASTFundamental Research Funds for the Central Universities。
文摘To develop an efficient way to overcome the contradiction among flame retardancy,smoke suppression,and thermal insulation in expanded polystyrene(EPS)foams,which are widely used insulation materials in buildings,a novel"green"porous bio-based flame-retard ant starch(FRS)coating was designed from starch modified with phytic acid(PA)that simultaneously acts as both a flame retardant and an adhesive.This porous FRS coating has open pores,which,in combination with the closed cells formed by EPS beads,create a hierarchically porous structure in FRS-EPS that results in superior thermal insulation with a lower thermal conductivity of 27.0 mW·(m·K)^(-1).The resultant FRS-EPS foam showed extremely low heat-release rates and smoke-production release,indicating excellent fire retardancy and smoke suppression.The specific optical density was as low as 121,which was 80.6%lower than that of neat EPS,at 624.The FRS-EPS also exhibited self-extinguishing behavior in vertical burning tests and had a high limiting oxygen index(LOI)value of 35.5%.More interestingly,after being burnt with an alcohol lamp for 30 min,the top side temperature of the FRS-EPS remained at only 140℃with ignition,thereby exhibiting excellent fire resistance.Mechanism analysis confirmed the intumescent action of FRS,which forms a compact phosphorus-rich hybrid barrier,and the phosphorus-containing compounds that formed in the gas phase contributed to the excellent flame retardancy and smoke suppression of FRS-EPS.This novel porous biomass-based FRS system provides a promising strategy for fabricating polymer foams with excellent flame retardancy,smoke suppression,and thermal insulation.
文摘该文采用动态低频振幅(dynamic amplitude of low frequency fluctuation,dALFF)方法探究青少年吸烟成瘾者脑功能网络的异常,为理解青少年吸烟成瘾的机制提供新视角。通过独立成分分析、滑动窗口法、K-means聚类方法分析青少年吸烟成瘾者在默认模式网络(default mode network,DMN)、左侧执行控制网络(left executive control network,LECN)、右侧执行控制网络(right executive control network,RECN)和突显网络(salience network,SAN)的动态低频振幅(dALFF)异常。同时,使用皮尔逊相关性分析评估动态指标(时间分数和平均停留时间)与吸烟统计学数据(FTND,烟龄,包年)的关系。相较于青少年健康非吸烟者,青少年吸烟成瘾者在默认模式网络(DMN)、左侧执行控制网络(LECN)、右侧执行控制网络(RECN)和突显网络(SAN)的激活程度降低,皮尔逊相关性分析表明dALFF在状态2时的平均停留时间和包年呈显著正相关。吸烟成瘾会导致青少年的部分脑功能网络异常,其激活程度会降低,同时这些脑区的功能异常与吸烟者的包年存在关联。
