Background Kurtosis reflecting noise's temporal structure is an effective metric for evaluating noise-induced hearing loss (NIHL), and its threshold is still unclear. Objective To explore the energy range of kurtosis and the threshold of NIHL induced by kurtosis in this energy rangeMethods Using cross-sectional design, 4631 noise-exposed workers in manufacturing industry were selected. The hearing loss and noise exposure data of each worker were collected. Logistic regression model was used to establish the dose-response relationship between noise exposure and hearing loss and estimate the range of energy effects. Restricted cubic spline model was utilized to analyze the dose-response relationship curves of kurtosis to noise-induced hearing loss (NIHI) and high-frequency noise-induced hearing loss (HFNIHL) under different 8 h equivalent sound levels (L_{EX,8 h}), as well as to estimate the kurtosis effect threshold. Results The logistic regression model analysis showed that the prevalence of NIHI and HFNIHL increased significantly with increase of L_{EX,8 h} for steady noise; when L_{EX,8 h} of non-steady noise was 80-100 dB(A), the risk of hearing loss increased with an increase in kurtosis (P<0.05). The restricted cubic spline model showed that when L_{EX,8 h} of non-steady noise was 0-80 dB(A) or >100 dB(A), there was no significant relationship between kurtosis and NIHI or HFNIHL. When L_{EX,8 h} was 80-100 dB(A), there was a significant nonlinear dose-response relationship between kurtosis and NIHL or HFNIHL (P <0.001), and kurtosis > 28.08 exerted effect in elevating NIHI or HFNIHL. Conclusion The effect threshold of kurtosis on NIHL is 28.08 when non-steady noise levels are in the range of 80-100 dB(A). The effect threshold of kurtosis needs further verification.

Background Temporal kurtosis (without frequency weighting, i.e., Z-weighted kurtosis) can evaluate noise-induced hearing loss (NIHL). However, few studies have considered the function of frequency weighting (A- or C-weighted) kurtosis on NIHL. Objective To study the significance of A- and C-weighted kurtosis adjustment for equivalent sound level (L'_{EX,8 h}) in evaluating occupational hearing loss. Methods A cross-sectional survey was used to select 973 noise-exposed workers in seven industries as the subjects. The noise exposure of all workers was assessed by distributions of A-, C-, and Z-weighted kurtosis (e.g., K_A, K_C, and K_Z) and respective adjusted equivalent sound level (e.g., L'_{EX,8 h}-K_A, L'_{EX,8 h}-K_C, and L'_{EX,8 h}-K_Z). The significance of A- and C-weighted kurtosis in evaluating NIHL was evaluated by correlations between three types of L'_{EX,8 h} and NIHL, and improvement of noise-induced permanent threshold shift (NIPTS) underestimation predicted by the ISO prediction model (Acoustics—Estimation of noise-induced hearing loss, ISO 1999-2013). Results The median K_A, K_C, and K_Z were 68.33, 28.22, and 19.82, respectively. The binary logistic regression showed that L_{EX, 8 h}-K_A, L_{EX, 8 h}-K_C, and L'_{EX, 8 h}-K_Z were risk factors for NIHL (OR>1, P<0.001). The receiver operating characteristic (ROC) curve showed that when the outcome variable was noise-induced hearing impairment (NIHI), the areas under the curves corresponding to L'_{EX,8 h}-K_A, L'_{EX,8 h}-K_C, and L'_{EX,8 h}-K_Z were 0.625, 0.628, and 0.625, respectively. When the outcome variable was high-frequency noise-induced hearing loss (HFNIHL), the areas under the curves corresponding to L'_{EX,8 h}-K_A, L'_{EX, 8 h}-K_C, and L'_{EX,8 h}-K_Z were 0.624, 0.623, and 0.622, respectively (P<0.05). The order of underestimation improvement values predicted by L'_{EX,8 h} for NIPTS₁₂₃₄ was: L'_{EX,8 h}-K_A (4.68 dB HL)>L'_{EX,8 h}-K_C (4.38 dB HL)>L'_{EX,8 h}-K_Z (4.28 dB HL) (P<0.001). The order of underestimation improvement values predicted by L'_{EX,8 h}-K for NIPTS₃₄₆ was: L'_{EX,8 h}-K_A (7.20 dB HL)>L'_{EX,8 h}-K_C (6.83 dB HL)>L'_{EX,8 h}-K_Z (6.71 dB HL) (P<0.001). Conclusion The adjustment of A- and C-weighted kurtosis to equivalent sound level L_{EX,8 h} can effectively improve the accuracy of the ISO 1999 prediction model in NIPTS prediction, and compared with the C-weighted, the A-weighted kurtosis can improve the result of the ISO 1999 prediction model in terms of underestimating NIPTS.

BACKGROUND:Previous studies have reported inconsistent results with positive,negative,and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection(AAD).This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD. METHODS:The UK Biobank study is a population-based cohort study.Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score(GRS).Cox proportional hazards models were used to estimate hazard ratios(HRs)with 95%confidence intervals(CIs)for the associations between alcohol consumption and AAD.Several sensitivity analyses were performed to assess the robustness of the results. RESULTS:Among the 388,955 participants(mean age:57.1 years,47.4%male),2,895 incident AAD cases were documented during a median follow-up of 12.5 years.Compared with never-drinkers,moderate drinkers(adjusted HR:0.797,95%CI:0.646-0.984,P<0.05)and moderate-heavy drinkers(adjusted HR:0.794,95%CI:0.635-0.992,P<0.05)were significantly associated with a decreased risk of incident AAD.Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women. CONCLUSION:Our findings support a protective effect of moderate alcohol consumption on AAD,but are limited to participants younger than 65 years and women.

BACKGROUND:Previous studies have reported inconsistent results with positive,negative,and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection(AAD).This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD. METHODS:The UK Biobank study is a population-based cohort study.Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score(GRS).Cox proportional hazards models were used to estimate hazard ratios(HRs)with 95%confidence intervals(CIs)for the associations between alcohol consumption and AAD.Several sensitivity analyses were performed to assess the robustness of the results. RESULTS:Among the 388,955 participants(mean age:57.1 years,47.4%male),2,895 incident AAD cases were documented during a median follow-up of 12.5 years.Compared with never-drinkers,moderate drinkers(adjusted HR:0.797,95%CI:0.646-0.984,P<0.05)and moderate-heavy drinkers(adjusted HR:0.794,95%CI:0.635-0.992,P<0.05)were significantly associated with a decreased risk of incident AAD.Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women. CONCLUSION:Our findings support a protective effect of moderate alcohol consumption on AAD,but are limited to participants younger than 65 years and women.

BACKGROUND:Previous studies have reported inconsistent results with positive,negative,and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection(AAD).This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD. METHODS:The UK Biobank study is a population-based cohort study.Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score(GRS).Cox proportional hazards models were used to estimate hazard ratios(HRs)with 95%confidence intervals(CIs)for the associations between alcohol consumption and AAD.Several sensitivity analyses were performed to assess the robustness of the results. RESULTS:Among the 388,955 participants(mean age:57.1 years,47.4%male),2,895 incident AAD cases were documented during a median follow-up of 12.5 years.Compared with never-drinkers,moderate drinkers(adjusted HR:0.797,95%CI:0.646-0.984,P<0.05)and moderate-heavy drinkers(adjusted HR:0.794,95%CI:0.635-0.992,P<0.05)were significantly associated with a decreased risk of incident AAD.Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women. CONCLUSION:Our findings support a protective effect of moderate alcohol consumption on AAD,but are limited to participants younger than 65 years and women.

BACKGROUND:Previous studies have reported inconsistent results with positive,negative,and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection(AAD).This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD. METHODS:The UK Biobank study is a population-based cohort study.Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score(GRS).Cox proportional hazards models were used to estimate hazard ratios(HRs)with 95%confidence intervals(CIs)for the associations between alcohol consumption and AAD.Several sensitivity analyses were performed to assess the robustness of the results. RESULTS:Among the 388,955 participants(mean age:57.1 years,47.4%male),2,895 incident AAD cases were documented during a median follow-up of 12.5 years.Compared with never-drinkers,moderate drinkers(adjusted HR:0.797,95%CI:0.646-0.984,P<0.05)and moderate-heavy drinkers(adjusted HR:0.794,95%CI:0.635-0.992,P<0.05)were significantly associated with a decreased risk of incident AAD.Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women. CONCLUSION:Our findings support a protective effect of moderate alcohol consumption on AAD,but are limited to participants younger than 65 years and women.

BACKGROUND:Previous studies have reported inconsistent results with positive,negative,and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection(AAD).This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD. METHODS:The UK Biobank study is a population-based cohort study.Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score(GRS).Cox proportional hazards models were used to estimate hazard ratios(HRs)with 95%confidence intervals(CIs)for the associations between alcohol consumption and AAD.Several sensitivity analyses were performed to assess the robustness of the results. RESULTS:Among the 388,955 participants(mean age:57.1 years,47.4%male),2,895 incident AAD cases were documented during a median follow-up of 12.5 years.Compared with never-drinkers,moderate drinkers(adjusted HR:0.797,95%CI:0.646-0.984,P<0.05)and moderate-heavy drinkers(adjusted HR:0.794,95%CI:0.635-0.992,P<0.05)were significantly associated with a decreased risk of incident AAD.Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women. CONCLUSION:Our findings support a protective effect of moderate alcohol consumption on AAD,but are limited to participants younger than 65 years and women.

BACKGROUND:Previous studies have reported inconsistent results with positive,negative,and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection(AAD).This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD. METHODS:The UK Biobank study is a population-based cohort study.Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score(GRS).Cox proportional hazards models were used to estimate hazard ratios(HRs)with 95%confidence intervals(CIs)for the associations between alcohol consumption and AAD.Several sensitivity analyses were performed to assess the robustness of the results. RESULTS:Among the 388,955 participants(mean age:57.1 years,47.4%male),2,895 incident AAD cases were documented during a median follow-up of 12.5 years.Compared with never-drinkers,moderate drinkers(adjusted HR:0.797,95%CI:0.646-0.984,P<0.05)and moderate-heavy drinkers(adjusted HR:0.794,95%CI:0.635-0.992,P<0.05)were significantly associated with a decreased risk of incident AAD.Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women. CONCLUSION:Our findings support a protective effect of moderate alcohol consumption on AAD,but are limited to participants younger than 65 years and women.

BACKGROUND:Previous studies have reported inconsistent results with positive,negative,and J-shaped associations between alcohol consumption and the hazard of aortic aneurysm and dissection(AAD).This study aimed to examine the connections between weekly alcohol consumption and the subsequent risk of AAD. METHODS:The UK Biobank study is a population-based cohort study.Weekly alcohol consumption was assessed using self-reported questionnaires and the congenital risk of alcohol consumption was also evaluated using genetic risk score(GRS).Cox proportional hazards models were used to estimate hazard ratios(HRs)with 95%confidence intervals(CIs)for the associations between alcohol consumption and AAD.Several sensitivity analyses were performed to assess the robustness of the results. RESULTS:Among the 388,955 participants(mean age:57.1 years,47.4%male),2,895 incident AAD cases were documented during a median follow-up of 12.5 years.Compared with never-drinkers,moderate drinkers(adjusted HR:0.797,95%CI:0.646-0.984,P<0.05)and moderate-heavy drinkers(adjusted HR:0.794,95%CI:0.635-0.992,P<0.05)were significantly associated with a decreased risk of incident AAD.Interaction-based subgroup analysis revealed that the protective effect of moderate drinking was reflected mainly in participants younger than 65 years and women. CONCLUSION:Our findings support a protective effect of moderate alcohol consumption on AAD,but are limited to participants younger than 65 years and women.

Objective To investigate the effect of the 5-HT1A receptor antagonist on synaptic plasticity in flurane-induced cognitive dys-function in aged rats.Methods Thirty 18-month-old Sprague-Dawley rats were randomly divided into control,model,and drug groups.The model group inhaled a 50%oxygen gas mixture(2 L/min)and 2%sevoflurane and were then treated with 5μL 0.9%NaCl;the drug group inhaled a 50%oxygen mixture(2 L/min)and 2%sevoflurane for 4 h and then the 5-HT1A receptor antagonist(3μg)was injected into the left ventricles of the rats;and the control group inhaled a 50%oxygen mixture(2 L/min)for 4 h.The water maze method was used to assess the learning memory of the rats and histopathological changes in the rat hippocampus were examined by HE staining.Nissl and Golgi staining were used to identify any changes to the neurons and synapses in hippocampal tissue.The MeCP2,p250GAP,PSD-95,GAP-43,and Syn expression levels were determined by immunofluorescence assay and the PKA,CREB1,and BDNFmRNA levels were determined using real-time PCR.Western blotting was performed to determine the PKA,CREB1,p-CREB1,and BDNF expression levels.Results The water maze data showed that the escape latency was significantly prolonged in the model group compared to the control group and,after treatment with the 5-HT1A receptor antagonist,the escape latency significantly decreased in the drug group compared to that of the model group(P<0.05).Moreover,the number of platform crossings was significantly lower in the model group than in the control group,but the number of platform crossings in the drug group was significantly higher than that in the model group(P<0.05).Compared to the control group,the hippocampal neurons in the model group had irregular morphology,loosely arranged and enlarged sur-rounding tissue gaps,deeply stained nuclei,a reduced number of Nissl bodies in the neurons,and a significantly reduced dendritic spine density and number of branches.After treatment with the 5-HT1A receptor antagonist,the hippocampal neurons in the drug group had a regular morphology,relatively complete structure,uniform arrangement,increased numbers of Nissl bodies in the neurons,and a signifi-cantly increased dendritic spine density and number of dendritic branches.Compared to the control group,MeCP2,PSD-95,GAP-43,Syn,PKA,CREB1,p-CREB1,and BDNF expression levels significantly decreased and p250GAP expression significantly increased in the rat brain tissue from the model group(P<0.05),but the PKA,CREB1,and BDNF mRNA levels significantly decreased(P<0.05).Furthermore,compared to the model group,the MeCP2,PSD-95,GAP-43,Syn,PKA,CREB1,p-CREB1,and BDNF expres-sion levels significantly increased along with the PKA,CREB1,and BDNF mRNA levels(P<0.05)in the drug group.However,the p250GAP protein expression level significantly decreased(P<0.05).Conclusion The 5-HT1A receptor antagonist improves learning memory in rats with sevoflurane-induced cognitive dysfunction.Specifically,it enhances PSD-95,GAP-43,and Syn expression levels,pro-motes synaptic remodeling,and protects rat hippocampal neuronal cells by activating the CREB/BDNF pathway.