ObjectiveTo explore the mechanism by which modified Shaofu Zhuyutang inhibits angiogenesis in endometriosis via the vascular endothelial growth factor （VEGF）/phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/endothelial nitric oxide synthase （eNOS）-nitric oxide （NO） signaling pathway. MethodsEighty-four female SD rats were randomly assigned into blank， sham operation， model， positive control （gestrinone， 0.25 mg·kg^-1）， high-， medium-， and low-dose （30， 15， 7.5 g·kg^-1， respectively） traditional Chinese medicine （TCM， modified Shaofu Zhuyutang） groups. A rat model of endometriosis was established by the autotransplantation method. After successful modeling， rats in the drug intervention groups were administrated with corresponding agents by gavage， and those in the blank， sham operation， and model groups received an equal volume of distilled water. After 28 days of gavage， rats were administrated with oxytocin， and the number and latency period of writhing responses were observed. Serum samples from each group， ectopic lesions from modeling groups， and uteri from blank and sham operation groups were collected. Hematoxylin-eosin staining was used to observe the pathological morphology of endometriotic lesions. Immunohistochemistry was employed to observe the expression of angiogenesis-specific markers cluster of differentiation 34 antigen （CD34） and friend leukemia virus integration-1 （FLI-1）. Enzyme-linked immunosorbent assay and the nitrate reductase method were employed to determine the serum levels of VEGF and NO， respectively. Western blot was employed to measure the protein levels of VEGF， PI3K， phosphorylated PI3K （p-PI3K）， Akt， phosphorylated Akt （p-Akt）， eNOS， and phosphorylated eNOS （p-eNOS）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was conducted to determine the mRNA levels of VEGF， PI3K， Akt， and eNOS. ResultsThe blank group and the sham operation group had no significant changes in the number and latency period of writhing responses， serum VEGF and NO levels， protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS， and mRNA levels of VEGF， PI3K， Akt， and eNOS. The model group showed an increase in the number and a reduction in the latency period of writhing responses， enlargement of ectopic endometrial tissue in the abdominal wall， with stromal hyperplasia， glandular dilation， and increased vasculature. In addition， the modeling led to increased positive expression of CD34 and FLI-1， elevated serum VEGF and NO levels， and up-regulated protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS and mRNA levels of VEGF， PI3K， Akt， and eNOS （P<0.01）. Compared with the model group， the gestrinone and high-， medium-， and low-dose TCM groups showed a significant reduction in the number of writhing responses， a significant prolongation of the latency period， reduced ectopic endometrial tissue in the abdominal wall， alleviated pathological damage， and reduced positive expression of CD34 and FLI-1. The gestrinone group and the high- and medium-dose TCM groups showed lowered serum VEGF and NO levels as well as down-regulated protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS and mRNA levels of VEGF， PI3K， Akt， and eNOS. Moreover， the low-dose TCM group showed reductions in the serum VEGF level， the protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS， and the mRNA levels of VEGF and eNOS （P<0.05， P<0.01）. ConclusionModified SShaofu Zhuyutang can inhibit angiogenesis in endometriosis by antagonizing the abnormal activation of the VEGF/PI3K/Akt/eNOS-NO signaling pathway， thereby preventing the occurrence， development， and deterioration of endometriosis.

ObjectiveTo explore the mechanism by which modified Shaofu Zhuyutang inhibits angiogenesis in endometriosis via the vascular endothelial growth factor （VEGF）/phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/endothelial nitric oxide synthase （eNOS）-nitric oxide （NO） signaling pathway. MethodsEighty-four female SD rats were randomly assigned into blank， sham operation， model， positive control （gestrinone， 0.25 mg·kg^-1）， high-， medium-， and low-dose （30， 15， 7.5 g·kg^-1， respectively） traditional Chinese medicine （TCM， modified Shaofu Zhuyutang） groups. A rat model of endometriosis was established by the autotransplantation method. After successful modeling， rats in the drug intervention groups were administrated with corresponding agents by gavage， and those in the blank， sham operation， and model groups received an equal volume of distilled water. After 28 days of gavage， rats were administrated with oxytocin， and the number and latency period of writhing responses were observed. Serum samples from each group， ectopic lesions from modeling groups， and uteri from blank and sham operation groups were collected. Hematoxylin-eosin staining was used to observe the pathological morphology of endometriotic lesions. Immunohistochemistry was employed to observe the expression of angiogenesis-specific markers cluster of differentiation 34 antigen （CD34） and friend leukemia virus integration-1 （FLI-1）. Enzyme-linked immunosorbent assay and the nitrate reductase method were employed to determine the serum levels of VEGF and NO， respectively. Western blot was employed to measure the protein levels of VEGF， PI3K， phosphorylated PI3K （p-PI3K）， Akt， phosphorylated Akt （p-Akt）， eNOS， and phosphorylated eNOS （p-eNOS）. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was conducted to determine the mRNA levels of VEGF， PI3K， Akt， and eNOS. ResultsThe blank group and the sham operation group had no significant changes in the number and latency period of writhing responses， serum VEGF and NO levels， protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS， and mRNA levels of VEGF， PI3K， Akt， and eNOS. The model group showed an increase in the number and a reduction in the latency period of writhing responses， enlargement of ectopic endometrial tissue in the abdominal wall， with stromal hyperplasia， glandular dilation， and increased vasculature. In addition， the modeling led to increased positive expression of CD34 and FLI-1， elevated serum VEGF and NO levels， and up-regulated protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS and mRNA levels of VEGF， PI3K， Akt， and eNOS （P<0.01）. Compared with the model group， the gestrinone and high-， medium-， and low-dose TCM groups showed a significant reduction in the number of writhing responses， a significant prolongation of the latency period， reduced ectopic endometrial tissue in the abdominal wall， alleviated pathological damage， and reduced positive expression of CD34 and FLI-1. The gestrinone group and the high- and medium-dose TCM groups showed lowered serum VEGF and NO levels as well as down-regulated protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS and mRNA levels of VEGF， PI3K， Akt， and eNOS. Moreover， the low-dose TCM group showed reductions in the serum VEGF level， the protein levels of VEGF， p-PI3K/PI3K， p-Akt/Akt， and p-eNOS/eNOS， and the mRNA levels of VEGF and eNOS （P<0.05， P<0.01）. ConclusionModified SShaofu Zhuyutang can inhibit angiogenesis in endometriosis by antagonizing the abnormal activation of the VEGF/PI3K/Akt/eNOS-NO signaling pathway， thereby preventing the occurrence， development， and deterioration of endometriosis.

ObjectiveTo investigate the mechanism of action of modified Shaofu Zhuyutang in antagonizing cellular pyroptosis and fibrosis in ectopic endometrial tissues of endometriosis through the Toll-like receptor 4/nuclear factor-κB/NOD-like receptor protein 3 （TRL4/NF-κB/NLPR3） signaling pathway. MethodsSeventy-two SPF-grade female SD rats were randomly divided into a sham-operated group （n = 12） and a modeling group （n = 60）. The rats in the sham-operated group underwent a caesarean section， while the rats in the modeling group were used to establish an endometriosis model through the auto-transplantation method. After successful modeling， the animals were randomly divided into the model group， progesterone group （0.25 mg·kg^-1）， and modified Shaofu Zhuyutang low-， medium-， and high-dose groups （7.5， 15， 30 g·kg^-1）， with 12 animals in each group. After 4 weeks of drug administration， voluntary activity and heat pain latency were observed. The rats were sacrificed for tissue collection， and Masson staining were used to observe histopathological changes in the endometrial tissues. Enzyme-linked immunosorbent assay （ELISA） was used to measure serum levels of interleukin-18 （IL-18）， interleukin-1β （IL-1β）， tumor necrosis factor-α （TNF-α）， and transforming growth factor-β （TGF-β）. Immunohistochemistry （IHC） was used to detect the protein expression area of tumor necrosis factor-related factor 6 （TRAF6） and NLPR3 in the endometrial tissues. Immunofluorescence （IF） was used to detect the relative fluorescence intensity of Caspase-1 and gasdermin D （GSDMD） in the endometrial tissues. Western blot was employed to measure the relative expression of TRL4， myeloid differentiation factor 88 （MyD88）， TRAF6， NF-κB p65， phosphorylated NF-κB p65 （p-NF-κB p65）， and NLPR3 proteins in endometrial tissues. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression of TRL4， MyD88， TRAF6， NF-κB， and NLPR3 in the endometrial tissues. ResultsCompared with the sham-operated group， rats in the model group showed reduced voluntary activity and shorter heat pain latency. Serum levels of IL-18， IL-1β， TNF-α， and TGF-β were elevated. The relative expression areas of TRAF6 and NLPR3 proteins were increased， and the relative fluorescence intensity of Caspase-1 and GSDMD was enhanced. The relative expression of TRL4， MyD88， TRAF6， NF-κB p65， p-NF-κB p65， and NLPR3 proteins， along with the expression of TRL4， MyD88， TRAF6， NF-κB， and NLPR3 mRNA， were significantly increased （P<0.01）. Compared with the model group， rats in the progesterone group and the modified Shaofu Zhuyutang medium- and high-dose groups exhibited improved voluntary activity， longer heat pain latency， the fibrosis of endometrial tissue is alleviated. Serum levels of IL-18， IL-1β， TNF-α， and TGF-β were decreased. The relative expression areas of TRAF6 and NLPR3 proteins decreased， and the relative fluorescence intensity of Caspase-1 and GSDMD weakened. The relative expression of TRL4， MyD88， TRAF6， p-NF-κB p65， NLPR3 proteins， and TRL4， MyD88， TRAF6， NF-κB， and NLPR3 mRNA expression were reduced （P<0.05， P<0.01）. ConclusionModified Shaofu Zhuyutang may play a therapeutic role in endometriosis by interfering with key proteins in the TRL4/NF-κB/NLPR3 signaling pathway， reducing NLRP3 inflammasome-induced cellular pyroptosis， antagonizing the fibrosis process in ectopic endometrial tissues， improving the inflammatory microenvironment in the pelvic cavity， and alleviating pain.

ObjectiveTo observe the effects of modified Shaofu Zhuyutang on key proteins of the epidermal growth factor receptor （EGFR）/phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt） signaling pathway in SD rats with endometriosis. MethodsAfter successful establishment of an endometriosis model in 60 female SD rats of SPF grade via the auto-transplantation method， the rats were randomly divided into a model group， modified Shaofu Zhuyutang high-， medium-， and low-dose groups， and a gestrinone group， with another 12 rats serving as a blank group. The blank and model groups were administered 10 mL·kg^-1 normal saline， while the high-， medium-， and low-dose groups received 30， 15， and 7.5 g·kg^-1 modified Shaofu Zhuyutang， respectively. The gestrinone group was administered 0.25 mg·kg^-1 gestrinone suspension. After four weeks of treatment， uterine contractions were induced with 2 U of oxytocin， and the writhing response of rats was observed. After 24 h， the rats were euthanized， and the weight and volume of ectopic endometrial tissue were recorded. Hematoxylin-eosin （HE） staining was used to observe pathological changes in endometrial tissues， while the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling （TUNEL） assay was used to evaluate the apoptosis rate of endometrial tissues. Immunofluorescence was used to detect the relative expression areas of the B-cell lymphoma-2 gene-associated promoter （Bad） and B-cell lymphoma-2 （Bcl-2） proteins in endometrial tissues. Serum levels of interleukin-1β （IL-1β）， interleukin-6 （IL-6）， tumor necrosis factor-α （TNF-α）， epidermal growth factor （EGF）， and EGFR were measured by enzyme-linked immunosorbent assay （ELISA）. The relative protein expression levels of EGFR， PI3K， phosphorylated PI3K （p-PI3K）， Akt， and phosphorylated Akt （p-Akt） in endometrial tissues were analyzed by Western blot. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to detect the mRNA expression levels of EGFR， PI3K， and Akt. ResultsCompared with the blank group， the model group showed endometrial thickening， glandular and mesenchymal hyperplasia， a significant decrease in the relative expression area of Bad in ectopic endometrial tissues， a significant increase in the relative expression area of Bcl-2， and a significant reduction in the apoptosis rate as indicated by TUNEL staining. Serum levels of IL-1β， IL-6， TNF-α， EGF， and EGFR were significantly elevated （P<0.01）. The relative protein expression levels of EGFR， PI3K， p-PI3K， Akt， and p-Akt， as well as the mRNA expression levels of EGFR， PI3K， and Akt， were also significantly increased （P<0.01）. Compared with the model group， the high- and medium-dose groups of modified Shaofu Zhuyutang and the gestrinone group exhibited reduced glandular and mesenchymal hyperplasia to varying degrees， with dilated glandular lumens. The number of writhing responses was significantly reduced， the latency to writhing response was significantly prolonged， and the weight and volume of ectopic endometrial tissue were significantly decreased. The relative expression area of Bad in ectopic endometrial tissue was significantly increased， the relative expression area of Bcl-2 was significantly decreased， and the apoptosis rate was significantly elevated as shown by TUNEL staining. Serum levels of IL-1β， IL-6， TNF-α， EGF， and EGFR were significantly reduced， and the relative protein expression levels of EGFR， PI3K， p-PI3K， Akt， and p-Akt， as well as the mRNA expression levels of EGFR， PI3K， and Akt， were significantly decreased （P<0.05，P<0.01）. ConclusionModified Shaofu Zhuyutang may exert therapeutic effects on endometriosis by interfering with key proteins of the EGFR/PI3K/Akt signaling pathway and inducing apoptosis in ectopic endometrial tissue.

ObjectiveTo investigate the mechanism of modified Shaofu Zhuyutang in inducing ferroptosis in ectopic endometrial tissues of rats with endometriosis through the murine double minute 4 （MDM4）/tumor suppressor p53/glutathione peroxidase 4 （GPX4） signaling pathway. MethodsSeventy SPF-grade female SD rats were randomly divided into a blank group （n = 10）， a sham-operated group （n = 10）， and a modeling group （n = 50）. The sham-operated group underwent laparotomy， while the modeling group was subjected to the autotransplantation method to establish an endometriosis model. After successful modeling， the animals were randomly assigned to the model group， progesterone group （0.25 mg·kg^-1）， and modified Shaofu Zhuyutang high-， medium-， and low-dose groups （30， 15， and 7.5 g·kg^-1， respectively）， with 10 rats per group. After four weeks of drug administration， the rats were euthanized for sample collection. The weight and volume of ectopic endometrial tissues were recorded for each group. Transmission electron microscopy （TEM） was employed to observe ultrastructural changes in endometrial tissues， while Prussian blue staining was used to assess iron ion deposition. Serum levels of interleukin-6 （IL-6）， interleukin-1β （IL-1β）， and tumor necrosis factor-α （TNF-α） were measured by enzyme-linked immunosorbent assay （ELISA）. The relative levels of Fe²⁺， malondialdehyde （MDA）， and glutathione （GSH） in endometrial tissues were determined by colorimetric assay. Immunofluorescence （IF） was used to detect the relative fluorescence intensities of GSH and GPX4 in endometrial tissues. The relative expression levels of phosphatidylinositol 3-kinase （PI3K）， phosphorylated PI3K （p-PI3K）， protein kinase B （Akt）， phosphorylated Akt （p-Akt）， MDM4， p53， and GPX4 proteins were detected by Western blot. Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） was used to assess the mRNA expression of PI3K， Akt， MDM4， p53， and GPX4. ResultsCompared with the blank and sham-operated groups， the model group exhibited reduced ferroptotic damage in ultrastructural observations， decreased ferroptotic aggregates and positive iron ion expression area on Prussian blue staining， elevated serum IL-6， IL-1β， and TNF-α levels， reduced Fe²⁺ and MDA content， increased GSH content in endometrial tissues， and enhanced GSH and GPX4 fluorescence intensities （P<0.01）. The protein and mRNA expression levels of PI3K， p-PI3K， Akt， p-Akt， MDM4， and GPX4 were elevated， while those of p53 were decreased （P<0.01）. Compared with the model group， in the progesterone group and the modified Shaofu Zhuyutang high- and medium-dose groups， ferroptotic damage in ultrastructural observations was exacerbated to varying degrees by TEM， and ferroptotic aggregates and positive iron ion expression areas were increased on Prussian blue staining. Serum IL-6， IL-1β， and TNF-α levels decreased， Fe²⁺ and MDA content increased， and GSH content decreased in endometrial tissues. GSH and GPX4 fluorescence intensities weakened， while the protein and mRNA expression levels of PI3K， p-PI3K， Akt， p-Akt， MDM4， and GPX4 decreased， and those of p53 increased （P<0.05， P<0.01）. Conclusionmodified Shaofu Zhuyutang may exert therapeutic effects in endometriosis by inducing ferroptosis in ectopic endometrial tissues， alleviating inflammatory responses， and modulating key proteins in the MDM4/p53/GPX4 signaling pathway.

ObjectiveTo investigate the influenza vaccination coverage among kindergarten and primary school children in Zhejiang Province in 2023 and analyze the influencing factors, and to provide the basis for improving the effect of influenza vaccination in children. MethodsA multi-stage random cluster sampling method was used to select 3 681 parents of children from 10 primary schools and kindergartens based on economic level and geographical distribution in Zhejiang Province, who participated in an online questionnaire survey, including basic information about the children and their parents, parents’ knowledge about influenza, and their willingness to vaccination. ResultsAmong the 3 681 parents surveyed, 33.82% (1 245/3 681) reported that their children received influenza vaccination in 2023. Multivariate logistic regression analysis showed that factors contributing to children’s influenza vaccination included both parents [adjusted OR (95%CI): 1.56 (1.32‒1.84)] and children [6.04 (5.04‒7.27)] having a history of influenza vaccination, parents’ conviction the influenza vaccine could protect children from severe diseases [1.43 (1.19‒1.74)], and the willingness of most parents would let their children get vaccinated [1.40 (1.13‒1.74)]. In contrast, vaccine hesitancy among parents [0.55 (0.43‒0.69)] and the belief that influenza is just a common cold [0.80 (0.65‒1.00)] were hindering factors. ConclusionThe influenza vaccination coverage among children is insufficient. Both the vaccination history of parents and children, as well as parents’ correct understanding of influenza and the effectiveness of influenza vaccine, significantly influence the influenza vaccination status in children. Efforts to address vaccine hesitancy and misconceptions about influenza are essential to improve vaccination rates.

Ovarian cancer （OC） is a common gynecological malignant tumor in clinical practice. In the early stage，it is often asymptomatic，while in the late stage，it mainly presents with non-specific symptoms such as abdominal distension，poor appetite，and dull abdominal pain. Some patients may also have cachexia such as weight loss and anemia. Early diagnosis is difficult，and the mortality rate ranks first among gynecological malignant tumors，making OC a major challenge in clinical treatment. The classic Chinese medicine formula Guizhi Fulingwan comes from the Jingui Yaolue and has the effects of promoting blood circulation，removing blood stasis，and reducing abdominal lumps. In recent years，it has been widely used to treat OC with good results. This article summarized the clinical application of Guizhi Fulingwan in the treatment of OC from two aspects：The analysis of its basic prescriptions and clinical research. In terms of basic prescriptions，the formula has the ability to promote blood circulation，remove blood stasis，and reduce abdominal lumps. It can exert therapeutic effects considering both water and blood aspects and reduce abdominal lumps， with characteristics of simultaneous Yang warming and heat clearing and parallel supplementation and elimination. Through the methods of "circulation" and "supplementation"， it strengthens the body，dispels evil，and eliminates underlying symptoms. In clinical studies，Guizhi Fulingwan can be applied to various stages of patients with OC，which not only promotes the recovery of the body after OC surgery but also can be combined with chemotherapy and immunotherapy to synergistically treat advanced OC and enhance treatment efficacy. In addition，the formula can also alleviate various adverse reactions caused by chemotherapy，with high safety，improve patients' quality of life，prolong survival，and optimize tumor control effects. Based on the above analysis，this article elaborated on the current clinical research status of Guizhi Fulingwan combined with Western medicine in the treatment of OC and proposed suggestions and improvements to address the shortcomings in current clinical research，so as to provide reference for the clinical application of this formula in the treatment of OC and the construction of a combined traditional Chinese and Western medicine treatment model.

Ovarian cancer （OC） is a common gynecological malignant tumor in clinical practice. In the early stage，it is often asymptomatic，while in the late stage，it mainly presents with non-specific symptoms such as abdominal distension，poor appetite，and dull abdominal pain. Some patients may also have cachexia such as weight loss and anemia. Early diagnosis is difficult，and the mortality rate ranks first among gynecological malignant tumors，making OC a major challenge in clinical treatment. The classic Chinese medicine formula Guizhi Fulingwan comes from the Jingui Yaolue and has the effects of promoting blood circulation，removing blood stasis，and reducing abdominal lumps. In recent years，it has been widely used to treat OC with good results. This article summarized the clinical application of Guizhi Fulingwan in the treatment of OC from two aspects：The analysis of its basic prescriptions and clinical research. In terms of basic prescriptions，the formula has the ability to promote blood circulation，remove blood stasis，and reduce abdominal lumps. It can exert therapeutic effects considering both water and blood aspects and reduce abdominal lumps， with characteristics of simultaneous Yang warming and heat clearing and parallel supplementation and elimination. Through the methods of "circulation" and "supplementation"， it strengthens the body，dispels evil，and eliminates underlying symptoms. In clinical studies，Guizhi Fulingwan can be applied to various stages of patients with OC，which not only promotes the recovery of the body after OC surgery but also can be combined with chemotherapy and immunotherapy to synergistically treat advanced OC and enhance treatment efficacy. In addition，the formula can also alleviate various adverse reactions caused by chemotherapy，with high safety，improve patients' quality of life，prolong survival，and optimize tumor control effects. Based on the above analysis，this article elaborated on the current clinical research status of Guizhi Fulingwan combined with Western medicine in the treatment of OC and proposed suggestions and improvements to address the shortcomings in current clinical research，so as to provide reference for the clinical application of this formula in the treatment of OC and the construction of a combined traditional Chinese and Western medicine treatment model.

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.