目的探讨耳蜗电图对噪声导致的隐性听力损失的早期诊断价值。方法选取36例18～40岁的常频听阈正常受试者,其中18例有噪声暴露史的工人作为噪声暴露组,18例无噪声暴露史的正常受试者作为对照组,分别行纯音听阈测试(常频+高频)、噪声下言...目的探讨耳蜗电图对噪声导致的隐性听力损失的早期诊断价值。方法选取36例18～40岁的常频听阈正常受试者,其中18例有噪声暴露史的工人作为噪声暴露组,18例无噪声暴露史的正常受试者作为对照组,分别行纯音听阈测试(常频+高频)、噪声下言语测试以及耳蜗电图测试,比较各组检查结果。结果噪声暴露组和对照组18、20 kHz听阈检出率分别为55.6%、33.3%和88.9%、88.3%,噪声暴露组低于对照组,差异有统计学意义(P<0.05);10、12.5 kHz平均听阈分别为11.94±15.16、16.39±20.87 dB HL和3.89±15.20、6.94±20.87 dB HL,噪声暴露组高于对照组(P<0.05);言语测试结果示噪声暴露组和对照组信噪比损失平均值分别为4.62±2.52 dB和1.44±2.90 dB,噪声暴露组高于对照组(P<0.01)。耳蜗电图测试结果示,噪声暴露组SP/AP振幅比在96和90 dB nHL刺激强度下高于对照组,差异有统计学意义(P<0.05),SP/AP面积比在96 dB nHL刺激强度下高于对照组,差异有统计学意义(P<0.05)。结论高强度刺激下(96 dB nHL)耳蜗电图SP/AP振幅比和面积比对噪声导致的隐性听力损失检测有一定的参考价值。展开更多
Background:Complex noise and its relation to hearing loss are difficult to measure and evaluate.In complex noise measurement,individual exposure results may not accurately represent lifetime noise exposure.Thus,the me...Background:Complex noise and its relation to hearing loss are difficult to measure and evaluate.In complex noise measurement,individual exposure results may not accurately represent lifetime noise exposure.Thus,the mean LAeq,8 h values of individuals in the same workgroup were also used to represent LAeq,8h in our study.Our study aimed to explore whether the mean exposure levels of workers in the same workgroup represented real noise exposure better than individual exposure levels did.Methods:A cross-sectional study was conducted to establish a model for cumulative noise exposure (CNE) and hearing loss in 205 occupational noise-exposed workers who were recruited from two large automobile manufacturers in China.We used a personal noise dosimeter and a questionnaire to determine the workers' occupational noise exposure levels and exposure times,respectively.A qualified audiologist used standardized audiometric procedures to assess hearing acuity after at least 16 h of noise avoidance.Results:We observed that 88.3％ of workers were exposed to more than 85 dB(A) of occupational noise (mean:89.3 ± 4.2 dB(A)).The personal CNE (CNEp) and workgroup CNE (CNEg) were 100.5 ± 4.7 dB(A) and 100.5 ± 2.9 dB(A),respectively.In the binary logistic regression analysis,we established a regression model with high-frequency hearing loss as the dependent variable and CNE as the independent variable.The Wald value was 5.014 with CNEp as the independent variable and 8.653 with CNEg as the independent variable.Furthermore,we found that the figure for CNEg was more similar to the stationary noise reference than CNEp was.The CNEg model was better than the CNEp model.In this circumstance,we can measure some subjects instead of the whole workgroup and save manpower.Conclusions:In a complex noise environment,the measurements of average noise exposure level of the workgroup can improve the accuracy and save manpower.展开更多
Summary What is already known about this topic?Occupational noise-induced hearing loss(NIHL)has been the second most common occupational disease in China.Noise energy is the main risk factor for occupational NIHL.Evid...Summary What is already known about this topic?Occupational noise-induced hearing loss(NIHL)has been the second most common occupational disease in China.Noise energy is the main risk factor for occupational NIHL.Evidence shows the temporal structure of noise(as indicated by kurtosis metric)contribute to the development of NIHL.However,the role of the kurtosis metric in evaluating the risk of occupational NIHL associated with complex noise has been rarely reported.展开更多
It is well known that high-level noise exposure can lead to hearing loss.Noise-induced hearing loss(NIHL)continues to be one of the major occupational health hazards.An underlying assumption in current noise standards...It is well known that high-level noise exposure can lead to hearing loss.Noise-induced hearing loss(NIHL)continues to be one of the major occupational health hazards.An underlying assumption in current noise standards,e.g.,ISO 1999:2013(1),is that hearing loss is related to the total energy of the exposure.Thus,the risk of NIHL can be predicted according to the ISO 1999 prediction model.Unfortunately,the validity of the prediction model to correctly predict the NIHL for all types of noise exposure is still under question,especially for complex noise of impulsive character.展开更多
Background:Ebola virus disease has reemerged as a major public health crisis in Africa,with isolated cases also observed globally,during the current outbreak.Methods:To estimate the basic reproductive ratio R0,which i...Background:Ebola virus disease has reemerged as a major public health crisis in Africa,with isolated cases also observed globally,during the current outbreak.Methods:To estimate the basic reproductive ratio R0,which is a measure of the severity of the outbreak,we developed a SEIR(susceptible-exposed-infected-recovered)type deterministic model,and used data from the Centers for Disease Control and Prevention(CDC),for the Ebola outbreak in Liberia and Sierra Leone.Two different data sets are available:one with raw reported data and one with corrected data(as the CDC suspects under-reporting).Results:Using a deterministic ordinary differential equation transmission model for Ebola epidemic,the basic reproductive ratio R0 for Liberia resulted to be 1.757 and 1.9 for corrected and uncorrected case data,respectively.For Sierra Leone,R0 resulted to be 1.492 and 1.362 for corrected and uncorrected case data,respectively.In each of the two cases we considered,the estimate for the basic reproductive ratio was initially greater than unity leading to an epidemic outbreak.Conclusion:We obtained robust estimates for the value of R0 associated with the 2014 Ebola outbreak,and showed that there is close agreement between our estimates of R0.Analysis of our model also showed that effective isolation is required,with the contact rate in isolation less than one quarter of that for the infected non-isolated population,and that the fraction of high-risk individuals must be brought to less than 10%of the overall susceptible population,in order to bring the value of R0 to less than 1,and hence control the outbreak.展开更多
Dear Editor,Gut microorganisms process food in animal guts and release many metabolic by-products,which are predicted to influence host physiological processes such as energy and lipid metabolism.Here,we investigate h...Dear Editor,Gut microorganisms process food in animal guts and release many metabolic by-products,which are predicted to influence host physiological processes such as energy and lipid metabolism.Here,we investigate how succi-nate,a TCA cycle intermediate that is a major predicted release product of gut bacteria in Drosophila,influences the nutritional physiology of its Drosophila host.We ad-ministered succinate as a dietary supplement to microbe-free Drosophila,and quantified key nutritional indices.Dietary succinate significantly reduced fly lipid levels by up to~50%.This response was not replicated in paral-lel experiments conducted with dietary fumarate supple-ment,indicating that it could not be attributed to a gen-eral effect of TCA intermediates.We hypothesize that microbe-derived succinate may contribute to the reduced lipid content of Drosophila bearing gut bacteria,relative to axenic Drosophila.More generally,this study high-lights the importance of microbial-derived metabolites as regulators of host metabolism.展开更多
文摘目的探讨耳蜗电图对噪声导致的隐性听力损失的早期诊断价值。方法选取36例18～40岁的常频听阈正常受试者,其中18例有噪声暴露史的工人作为噪声暴露组,18例无噪声暴露史的正常受试者作为对照组,分别行纯音听阈测试(常频+高频)、噪声下言语测试以及耳蜗电图测试,比较各组检查结果。结果噪声暴露组和对照组18、20 kHz听阈检出率分别为55.6%、33.3%和88.9%、88.3%,噪声暴露组低于对照组,差异有统计学意义(P<0.05);10、12.5 kHz平均听阈分别为11.94±15.16、16.39±20.87 dB HL和3.89±15.20、6.94±20.87 dB HL,噪声暴露组高于对照组(P<0.05);言语测试结果示噪声暴露组和对照组信噪比损失平均值分别为4.62±2.52 dB和1.44±2.90 dB,噪声暴露组高于对照组(P<0.01)。耳蜗电图测试结果示,噪声暴露组SP/AP振幅比在96和90 dB nHL刺激强度下高于对照组,差异有统计学意义(P<0.05),SP/AP面积比在96 dB nHL刺激强度下高于对照组,差异有统计学意义(P<0.05)。结论高强度刺激下(96 dB nHL)耳蜗电图SP/AP振幅比和面积比对噪声导致的隐性听力损失检测有一定的参考价值。
文摘Background:Complex noise and its relation to hearing loss are difficult to measure and evaluate.In complex noise measurement,individual exposure results may not accurately represent lifetime noise exposure.Thus,the mean LAeq,8 h values of individuals in the same workgroup were also used to represent LAeq,8h in our study.Our study aimed to explore whether the mean exposure levels of workers in the same workgroup represented real noise exposure better than individual exposure levels did.Methods:A cross-sectional study was conducted to establish a model for cumulative noise exposure (CNE) and hearing loss in 205 occupational noise-exposed workers who were recruited from two large automobile manufacturers in China.We used a personal noise dosimeter and a questionnaire to determine the workers' occupational noise exposure levels and exposure times,respectively.A qualified audiologist used standardized audiometric procedures to assess hearing acuity after at least 16 h of noise avoidance.Results:We observed that 88.3％ of workers were exposed to more than 85 dB(A) of occupational noise (mean:89.3 ± 4.2 dB(A)).The personal CNE (CNEp) and workgroup CNE (CNEg) were 100.5 ± 4.7 dB(A) and 100.5 ± 2.9 dB(A),respectively.In the binary logistic regression analysis,we established a regression model with high-frequency hearing loss as the dependent variable and CNE as the independent variable.The Wald value was 5.014 with CNEp as the independent variable and 8.653 with CNEg as the independent variable.Furthermore,we found that the figure for CNEg was more similar to the stationary noise reference than CNEp was.The CNEg model was better than the CNEp model.In this circumstance,we can measure some subjects instead of the whole workgroup and save manpower.Conclusions:In a complex noise environment,the measurements of average noise exposure level of the workgroup can improve the accuracy and save manpower.
基金Zhejiang Province Key Research and Development Project,China(Grant No.2015C03039)Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents,China(Grant No.2016-63-07)+2 种基金Health Commission of Zhejiang Province(Grant No.2019KY057)the Program of Occupational Health Risk Assessment of China NIOHP(Grant No.131031109000160004)and the National Institute for Occupational Safety and Health,USA(Grant No.200-2015-M-63857,Grant No.200-2016-M-91922).
文摘Summary What is already known about this topic?Occupational noise-induced hearing loss(NIHL)has been the second most common occupational disease in China.Noise energy is the main risk factor for occupational NIHL.Evidence shows the temporal structure of noise(as indicated by kurtosis metric)contribute to the development of NIHL.However,the role of the kurtosis metric in evaluating the risk of occupational NIHL associated with complex noise has been rarely reported.
基金National Institute for Occupational Safety and Health,USA(Grant No.200-2015-M-63857,200-2016-M-91922)Zhejiang Province Key Research and Development Project,China(Grant No.2015C03039)+2 种基金Zhejiang Provincial Program for the Cultivation of High-level Innovative Health Talents,China(Grant No,2016-63-07)Program of Occupational Health Risk Assessment of China NIOHP(Grant No.131031109000160004)and Occupational Health Standards Preliminary Research Project of China NIOHP(Grant No.20210102).
文摘It is well known that high-level noise exposure can lead to hearing loss.Noise-induced hearing loss(NIHL)continues to be one of the major occupational health hazards.An underlying assumption in current noise standards,e.g.,ISO 1999:2013(1),is that hearing loss is related to the total energy of the exposure.Thus,the risk of NIHL can be predicted according to the ISO 1999 prediction model.Unfortunately,the validity of the prediction model to correctly predict the NIHL for all types of noise exposure is still under question,especially for complex noise of impulsive character.
文摘Background:Ebola virus disease has reemerged as a major public health crisis in Africa,with isolated cases also observed globally,during the current outbreak.Methods:To estimate the basic reproductive ratio R0,which is a measure of the severity of the outbreak,we developed a SEIR(susceptible-exposed-infected-recovered)type deterministic model,and used data from the Centers for Disease Control and Prevention(CDC),for the Ebola outbreak in Liberia and Sierra Leone.Two different data sets are available:one with raw reported data and one with corrected data(as the CDC suspects under-reporting).Results:Using a deterministic ordinary differential equation transmission model for Ebola epidemic,the basic reproductive ratio R0 for Liberia resulted to be 1.757 and 1.9 for corrected and uncorrected case data,respectively.For Sierra Leone,R0 resulted to be 1.492 and 1.362 for corrected and uncorrected case data,respectively.In each of the two cases we considered,the estimate for the basic reproductive ratio was initially greater than unity leading to an epidemic outbreak.Conclusion:We obtained robust estimates for the value of R0 associated with the 2014 Ebola outbreak,and showed that there is close agreement between our estimates of R0.Analysis of our model also showed that effective isolation is required,with the contact rate in isolation less than one quarter of that for the infected non-isolated population,and that the fraction of high-risk individuals must be brought to less than 10%of the overall susceptible population,in order to bring the value of R0 to less than 1,and hence control the outbreak.
文摘Dear Editor,Gut microorganisms process food in animal guts and release many metabolic by-products,which are predicted to influence host physiological processes such as energy and lipid metabolism.Here,we investigate how succi-nate,a TCA cycle intermediate that is a major predicted release product of gut bacteria in Drosophila,influences the nutritional physiology of its Drosophila host.We ad-ministered succinate as a dietary supplement to microbe-free Drosophila,and quantified key nutritional indices.Dietary succinate significantly reduced fly lipid levels by up to~50%.This response was not replicated in paral-lel experiments conducted with dietary fumarate supple-ment,indicating that it could not be attributed to a gen-eral effect of TCA intermediates.We hypothesize that microbe-derived succinate may contribute to the reduced lipid content of Drosophila bearing gut bacteria,relative to axenic Drosophila.More generally,this study high-lights the importance of microbial-derived metabolites as regulators of host metabolism.
