OBJECTIVE To investigate the mechanism of pachymic acid on renal injury in pregnancy induced hypertension （PIH） rats by regulating the silent information regulator transcript 1/peroxisome proliferator-activated receptor γ coactivator-1α （Sirt1/PGC-1α） pathway. METHODS Pregnant SD rats were prepared by co-caging and PIH model was induced using N-nitro-L- arginine methyl ester （L-NAME） method. PIH rats were randomly divided into model group， L-pachymic acid （low-dose pachymic acid， 10 mg/kg） group， H-pachymic acid （high-dose pachymic acid， 20 mg/kg） group， and H-pachymic acid+EX527 （20 mg/kg pachymic acid+10 mg/kg EX527） group， with 6 rats in each group. Another 6 normal pregnant rats were selected as blank group. Each group was given relevant medicine or solvent intragastrically or intraperitoneally daily， once a day， for 28 consecutive days. After the last administration， 24 h urinary protein and tail artery systolic blood pressure （SBP） were measured in pregnant rats from each group， along with the levels of serum creatinine （Scr）， blood urea nitrogen （BUN），uric acid （UA）， and cystatin C （Cys-C）. The contents of superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione peroxidase （GSH-Px）， and 8-hydroxy-2′-deoxyguanosine （8-OHdG） in renal tissue， as well as the mRNA and protein expression levels of Sirt1 and PGC-1α， were also determined. Meanwhile， renal histopathological changes in rats from each group were evaluated using hematoxylin-eosin （HE） staining and periodic acid-Schiff （PAS） staining. RESULTS Compared with model group， L-pachymic acid group and H-pachymic acid group exhibited significant decreases in 24 h urine protein quantification， tail artery SBP， Scr， BUN， UA， Cys-C levels， glomerulosclerosis index score of renal tissue， renal tubular injury score， the percentage of PAS positive area， MDA and 8-OHdG （P＜0.05）. Conversely， the contents of SOD and GSH-Px， along with the mRNA and protein expression levels of Sirt1 and PGC-1α， were significantly increased （P＜0.05）. Moreover， these improvements were more pronounced in H-pachymic acid group （P＜0.05）. Compared with H-pachymic acid group， the aforementioned indicators in pregnant rats from the H-pachymic acid+EX527 group showed significant reversal （P＜0.05）. CONCLUSIONS Pachymic acid significantly ameliorates renal injury induced by PIH in rats， potentially through activation of the Sirt1/PGC-1α pathway.

ObjectiveTo explore the mechanisms of Yangjing Tongluo prescription （YJTL） in the treatment of intrauterine adhesion （IUA） from the perspective of oxidative stress mediated by the Kelch-like ECH-associated protein 1/nuclear factor erythroid 2-related factor 2/heme oxygenase-1 （Keap1/Nrf2/HO-1） signaling pathway. MethodsA total of 48 rats with normal estrous cycles were selected and randomly divided into a normal group （n=8） and a modeling group （n=40）. An IUA rat model was established using a dual-injury method combining surgical curettage and infection. Eight rats were randomly selected from the modeling group for a pilot experiment to confirm successful model establishment. After successful modeling， the remaining 32 rats were randomly divided into a model group， a low-dose YJTL group （YJTL-L）， a high-dose YJTL group （YJTL-H）， and a Progynova group. Rats in the normal and model groups were administered purified water （15 mL·kg^-1） by gavage daily， while rats in the YJTL-L， YJTL-H， and Progynova groups received YJTL at doses of 6.43 and 12.86 g·kg^-1 and Progynova at 2.06 × 10^-4 g·kg^-1， respectively， for 14 consecutive days. The general condition， uterine morphology， and uterine index of the rats were monitored. Histopathological changes in uterine tissue were observed using hematoxylin-eosin （HE） staining. Serum levels of reactive oxygen species （ROS） and glutathione peroxidase （GSH-Px） were measured by enzyme-linked immunosorbent assay （ELISA）. Protein expression levels of Keap1， Nrf2， and HO-1 in endometrial tissue were detected by Western blot. Immunofluorescence （IF） was used to assess the distribution of Nrf2 and HO-1， as well as the expression of Nrf2 in the cytoplasm and nucleus. ResultsCompared with the normal group， rats in the model group exhibited poor mental status and reduced mobility， markedly edematous and tortuous uterine morphology， decreased gland number， and inflammatory reactions in the endometrium， along with an increased uterine organ index （P<0.05）. Serum ROS levels were significantly increased （P<0.05）， while serum GSH-Px levels were significantly decreased （P<0.05）. In endometrial tissue， Keap1 protein expression was increased （P<0.05）， whereas Nrf2 and HO-1 protein expression was decreased. Mild nuclear translocation of Nrf2 was observed， accompanied by increased relative fluorescence intensity of nuclear Nrf2 and decreased relative fluorescence intensity of cytoplasmic HO-1. Compared with the model group， all treatment groups showed varying degrees of improvement in the above symptoms and pathological changes. Serum ROS levels were reduced （P<0.05）， serum GSH-Px levels were increased （P<0.05）， Keap1 protein expression in endometrial tissue was decreased， and Nrf2 and HO-1 protein expression was increased in a dose-dependent manner （P<0.05）. Notably， significant nuclear translocation of Nrf2 was observed， with correspondingly increased relative fluorescence intensity of nuclear Nrf2 and enhanced relative fluorescence intensity of cytoplasmic HO-1. ConclusionYJTL may enhance antioxidant capacity and repair oxidative damage to the endometrial basal layer by regulating the Keap1/Nrf2/HO-1 signaling pathway.

Stroke is the leading cause of death and disability among adults in China， and its common complications include digestive system abnormalities， cognitive impairment， depression， stroke-associated pneumonia， and hemiplegia. The combination of traditional Chinese and Western medicine has great potential in treating post-stroke complications. Xinglou Chengqitang （XLCQT） is a representative prescription of alleviating the disease in the upper part by treating the lower part. It has definite therapeutic effect and high safety. Clinically， XLCQT is often used to treat stroke and its complications. However， the quantity and quality of clinical trials of XLCQT in treating post-stroke complications need to be improved. Additionally， since the basic research is weak， the material basis and multi-target mechanism for the efficacy of this prescription are unknown. This article reviews XLCQT in terms of the pharmacodynamic basis， medicinal properties， safety evaluation， and progress in clinical research and mechanisms in treating post-stroke complications. This article summarizes 22 key active ingredients of XLCQT in treating acute stroke complicated with syndrome of phlegm heat and fu-organ excess. Among these key active ingredients， resveratrol， kaempferol， luteolin， chrysoeriol， apigenin， （+）-catechin， and adenosine have good pharmacokinetic properties and high bioavailability. The mechanisms of XLCQT in treating post-stroke complications are complex， including inflammatory response， brain-gut axis， hypothalamic-pituitary-adrenal （HPA） axis， intestinal flora， neurotrophic factors， autophagy， oxidative stress， and free radical damage. This review helps to deeply understand the pharmacodynamic basis and mechanisms of XLCQT in treating post-stroke complications and provides a theoretical basis for the clinical application of XLCQT against post-stroke complications and the development of drugs.

ObjectiveTo elucidate the underlying mechanism through which Zhuluan decoction suppresses excessive autophagy in human ovarian granulosa cells （KGN） and ameliorates premature ovarian insufficiency （POI） via the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway. MethodsThe optimal concentration of cyclophosphamide for inducing a POI model in KGN cells was identified via the cell counting kit-8 （CCK-8） assay. Subsequently， the impacts of varying concentrations of Zhuluan decoction-containing serum on the viability of the KGN cell model were assessed. After the optimal drug concentration was determined， KGN cells were categorized into the following groups： blank control （20% blank serum）， model （20% blank serum + 5 μmol·L^-1 cyclophosphamide）， Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide）， autophagy inhibitor （20% blank serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， autophagy inhibitor + Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， and estradiol valerate （20% estradiol valerate-containing serum + 5 μmol·L^-1 cyclophosphamide）. Following 48 hours of incubation， flow cytometry was utilized to measure the apoptosis rate of KGN cells in each group. Western blotting was employed to quantify the protein levels of PI3K， phosphorylated （p）-Akt， Akt， p-mTOR， and mTOR， along with the expression levels of autophagy-related proteins such as Beclin1， autophagy-related 5 homolog （ATG5）， and microtubule-associated protein 1 light chain 3 （LC3）， in each group. Additionally， monodansylcadaverine （MDC） staining was performed to evaluate the extent of autophagy in each group. ResultsIncubation of KGN cells with 5 μmol·L^-1 cyclophosphamide for 48 h successfully established a POI model， marked by a significant inhibition of KGN cell proliferation. Notably， the inhibitory effect of cyclophosphamide on KGN cell proliferation exhibited a positive correlation with its concentration. Zhuluan decoction-containing serum at 20% and 30% promoted cell proliferation and mitigated the inhibitory effect of cyclophosphamide on KGN cell proliferation， with comparable therapeutic efficacy observed at both concentrations. Compared with the blank control group， the model group displayed an elevated apoptosis rate （P<0.01）， reduced protein levels of PI3K， p-Akt， and p-mTOR （P<0.01）， increased protein levels of Beclin1， LC3， and ATG5 （P<0.01）， no significant alterations in the protein levels of Akt and mTOR， and an enhanced MDC autophagy fluorescence intensity （P<0.01）. In comparison to that the model group， the apoptosis rates in the blank control group， model group， Zhuluan decoction-containing serum group， autophagy inhibitor group， autophagy inhibitor + Zhuluan decoction-containing serum group， and estradiol valerate group all reduced （P<0.05， P<0.01）， with the most pronounced reduction observed in the autophagy inhibitor + Zhuluan decoction-containing serum group. The protein levels of PI3K， p-Akt， and p-mTOR were higher in other groups than in the model group （P<0.05， P<0.01）， being the highest in the autophagy inhibitor + Zhuluan decoctio-containing serum group （P<0.01）. The protein levels of Beclin1 and ATG5 were lower in other groups than in the model group （P<0.05， P<0.01）. The expression level of LC3 declined in the Zhuluan decoction-containing serum group and the estradiol valerate group （P<0.05， P<0.01）， while it decreased without statistical significance in the autophagy inhibitor group and the autophagy inhibitor + Zhuluan decoction-containing serum group. ConclusionZhuluan decoction may activate the PI3K/Akt/mTOR pathway to inhibit excessive autophagy and counteract the detrimental effects of cyclophosphamide on the KGN cell model， thus managing POI.

ObjectiveTo elucidate the underlying mechanism through which Zhuluan decoction suppresses excessive autophagy in human ovarian granulosa cells （KGN） and ameliorates premature ovarian insufficiency （POI） via the phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/mammalian target of rapamycin （mTOR） signaling pathway. MethodsThe optimal concentration of cyclophosphamide for inducing a POI model in KGN cells was identified via the cell counting kit-8 （CCK-8） assay. Subsequently， the impacts of varying concentrations of Zhuluan decoction-containing serum on the viability of the KGN cell model were assessed. After the optimal drug concentration was determined， KGN cells were categorized into the following groups： blank control （20% blank serum）， model （20% blank serum + 5 μmol·L^-1 cyclophosphamide）， Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide）， autophagy inhibitor （20% blank serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， autophagy inhibitor + Zhuluan decoction-containing serum （20% Zhuluan decoction-containing serum + 5 μmol·L^-1 cyclophosphamide + 20 μmol·L^-1 chloroquine phosphate）， and estradiol valerate （20% estradiol valerate-containing serum + 5 μmol·L^-1 cyclophosphamide）. Following 48 hours of incubation， flow cytometry was utilized to measure the apoptosis rate of KGN cells in each group. Western blotting was employed to quantify the protein levels of PI3K， phosphorylated （p）-Akt， Akt， p-mTOR， and mTOR， along with the expression levels of autophagy-related proteins such as Beclin1， autophagy-related 5 homolog （ATG5）， and microtubule-associated protein 1 light chain 3 （LC3）， in each group. Additionally， monodansylcadaverine （MDC） staining was performed to evaluate the extent of autophagy in each group. ResultsIncubation of KGN cells with 5 μmol·L^-1 cyclophosphamide for 48 h successfully established a POI model， marked by a significant inhibition of KGN cell proliferation. Notably， the inhibitory effect of cyclophosphamide on KGN cell proliferation exhibited a positive correlation with its concentration. Zhuluan decoction-containing serum at 20% and 30% promoted cell proliferation and mitigated the inhibitory effect of cyclophosphamide on KGN cell proliferation， with comparable therapeutic efficacy observed at both concentrations. Compared with the blank control group， the model group displayed an elevated apoptosis rate （P<0.01）， reduced protein levels of PI3K， p-Akt， and p-mTOR （P<0.01）， increased protein levels of Beclin1， LC3， and ATG5 （P<0.01）， no significant alterations in the protein levels of Akt and mTOR， and an enhanced MDC autophagy fluorescence intensity （P<0.01）. In comparison to that the model group， the apoptosis rates in the blank control group， model group， Zhuluan decoction-containing serum group， autophagy inhibitor group， autophagy inhibitor + Zhuluan decoction-containing serum group， and estradiol valerate group all reduced （P<0.05， P<0.01）， with the most pronounced reduction observed in the autophagy inhibitor + Zhuluan decoction-containing serum group. The protein levels of PI3K， p-Akt， and p-mTOR were higher in other groups than in the model group （P<0.05， P<0.01）， being the highest in the autophagy inhibitor + Zhuluan decoctio-containing serum group （P<0.01）. The protein levels of Beclin1 and ATG5 were lower in other groups than in the model group （P<0.05， P<0.01）. The expression level of LC3 declined in the Zhuluan decoction-containing serum group and the estradiol valerate group （P<0.05， P<0.01）， while it decreased without statistical significance in the autophagy inhibitor group and the autophagy inhibitor + Zhuluan decoction-containing serum group. ConclusionZhuluan decoction may activate the PI3K/Akt/mTOR pathway to inhibit excessive autophagy and counteract the detrimental effects of cyclophosphamide on the KGN cell model， thus managing POI.

Objective To investigate the efficacy of early, short-term, low-dose corticosteroid administration for the prevention and treatment of early acute lung injury (EALI) in patients undergoing thoracoscopic lobectomy. Methods A retrospective analysis was conducted on the clinical data of patients who underwent thoracoscopic lobectomy at the Department of Thoracic and Cardiovascular Surgery, Taihe Hospital, Hubei University of Medicine, from January 2019 to January 2022. Patients were divided into an early steroid therapy group and an observation group based on whether they received corticosteroids in the early postoperative period. In the early steroid therapy group, in addition to standard postoperative care, patients received a low-dose intravenous push of methylprednisolone (80-120 mg/d) for 3 consecutive days. In the observation group, patients received standard postoperative care without intravenous corticosteroids for the first 3 days. Chest plain CT scans were performed on postoperative day (POD) 1 and POD 3 or 4 to evaluate lung injury. CT scores and the incidence of postoperative EALI were recorded. Results A total of 521 patients were included (268 males, 253 females; age range: 11-80 years). There were 318 patients in the observation group and 203 in the early steroid therapy group. On POD 1, the incidence of EALI was 16.0% in the observation group and 13.8% in the early steroid therapy group, with no statistical difference (P=0.486). Correspondingly, there was no statistical difference in chest CT scores among EALI-positive patients between the two groups (P=0.927). On POD 3-4, the incidence of EALI was significantly lower in the early steroid therapy group (22.7%) compared to the observation group (33.6%) (P=0.007). Although chest CT scores among EALI-positive patients were lower in the early steroid therapy group, the difference was not statistically significant (P=0.377). The overall incidence of EALI within the first 4 postoperative days was significantly lower in the early steroid therapy group (26.1%) than in the observation group (37.4%) (P=0.007). Radiological progression (defined as new-onset EALI or progression of existing EALI) occurred in 14.8% of the early steroid therapy group, significantly lower than the 28.9% in the observation group (P<0.001). The early steroid therapy group had a shorter postoperative length of stay (P<0.001), while there was no statistical difference in the incidence of poor wound healing between the groups (P=0.762). Conclusion Early postoperative corticosteroid use effectively reduces the incidence of EALI on POD 3-4, lowers the risk of radiological progression, and decreases the overall incidence of postoperative EALI. This is achieved without prolonging the length of stay or increasing the risk of poor wound healing. Therefore, early administration of low-dose corticosteroids is beneficial in suppressing the occurrence and progression of EALI. Its early use is recommended for patients at high risk for postoperative EALI.

BACKGROUND:At present,there are few reports on the postoperative efficacy of arthroscopic coracoid tunnel-free suspension fixation and coracoid single tunnel fixation in the treatment of acromioclavicular joint dislocation at home and abroad.The specific clinical efficacy of the two procedures and whether there are other risks need to be explored. OBJECTIVE:To compare the short-term postoperative clinical efficacy of arthroscopic TightRope band plate fixation with single tunnel fixation of the coracoid process and tunnel-free suspension fixation of the coracoid process in the treatment of acute type Ⅲ-Ⅴ acromioclavicular joint dislocation. METHODS:A retrospective analysis was performed in 45 patients with acromioclavicular joint dislocation who met the inclusion criteria admitted to the Sixth Affiliated Hospital of Xinjiang Medical University from June 2019 to September 2022,and were divided into coracoid single tunnel fixation group(20 cases)and coracoid tunnel-free suspension fixation group(25 cases)according to the surgical treatment plan.Operation time,incision length,blood loss,Constant-Murley score,visual analogue scale score,the American Shoulder and Elbow Surgeons(ASES)score and intraoperative and postoperative complications of the shoulder joint before operation,3 months after surgery and the last follow-up were compared between the two groups. RESULTS AND CONCLUSION:All patients successfully completed the operation,and there was no important nerve or blood vessel damage during the operation.The operation time of the coracoid tunnel-free suspension fixation group was significantly shorter than that of the coracoid tunnel-free suspension fixation group(P<0.05).There was no significant difference in intraoperative blood loss and incision length between the two groups(P>0.05).All patients were followed up for 12 to 24 months,with an average of(15.29±2.73)months.In the coracoid single tunnel fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);Constant-Murley score and ASES score were significantly increased compared with the preoperative values(P<0.05).In the coracoid tunnel-free suspension fixation group,at 3 months after operation and the final follow-up,the visual analogue scale score was significantly lower than the preoperative score(P<0.05);the Constant-Murley score and the ASES score were both significantly higher than the preoperative scores(P<0.05).At 3 months after operation,the Constant-Murley score of the coracoid tunnel-free suspension fixation group was higher than that of the coracoid single tunnel fixation group(P<0.05),while there was no significant difference in visual analogue scale and ASES scores between the two groups(P>0.05).There was also no significant difference in the visual analogue scale,Constant-Murley,and ASES scores between the two groups at the corresponding time points before surgery and at the final follow-up(P>0.05).Intraoperative and postoperative complications:In the coracoid single tunnel fixation group,there was one case of coracoid cortical rupture and fracture during the tunnel drilling during the operation,and one case of a loss of reduction at 3 months after operation,which was repositioned and fixed with hook plate transposition of the coracoacromial ligament.All patients had good acromioclavicular joint function recovery and no re-dislocation at the final follow-up.All patients in the coracoid tunnel-free suspension fixation group did not suffer from coracoid fractures,loss of reduction and other complications during surgery,postoperatively and at the last follow-up.To conclude,these two arthroscopic treatments for acute type Ⅲ-Ⅴ acromioclavicular joint dislocation have the advantages of less trauma,reliable reduction and fixation,and good recovery of shoulder joint function after operation.However,compared with the coracoid single tunnel technique,the coracoid tunnel-free suspension fixation requires shorter time,faster recovery of shoulder joint function in the short term,and avoids the establishment of bone tunnels on the coracoid process,which reduces the probability of iatrogenic fracture of the coracoid process during operation and provides a higher degree of safety.

BACKGROUND:Steroid-induced femoral head necrosis is mostly caused by long-term and extensive use of hormones,but its specific pathogenesis is not yet clear and needs further study. OBJECTIVE:To screen out the differential miRNAs in osteoclast exosomes after the intervention of Panax notoginseng saponins,and on this basis,to further construct an osteogenic-related ferroptosis regulatory network to explore the potential mechanism and research direction of steroid-induced osteonecrosis of the femoral head. METHODS:MTT assay was used to detect the toxic effects of different concentrations of dexamethasone and different mass concentrations of Panax notoginseng saponins on Raw264.7 cell line.Tartrate resistant acid phosphatase staining and TUNEL assay were used to detect the effects of Panax notoginseng saponins on osteoclast inhibition and apoptosis.Exosomes were extracted from cultured osteoclasts with Panax notoginseng saponins intervention.Exosomes from different groups were sequenced to identify differentially expressed miRNAs.CytoScape 3.9.1 was used to construct and visualize the regulatory network between differentially expressed miRNAs and mRNAs.Candidate mRNAs were screened by GO analysis and KEGG analysis.Finally,the differential genes related to ferroptosis were screened out,and the regulatory network of ferroptosis-related genes was constructed. RESULTS AND CONCLUSION:(1)The concentration of dexamethasone(0.1 μmol/L)and Panax notoginseng saponins(1 736.85 μg/mL)suitable for intervention of Raw264.7 cells was determined by MTT assay.(2)Panax notoginseng saponins had an inhibitory effect on osteoclasts and could promote their apoptosis.(3)Totally 20 differentially expressed miRNAs were identified from osteoclast-derived exosome samples,and 11 differentially expressed miRNAs related to osteogenesis were predicted by target mRNAs.The regulatory networks of 4 up-regulated differentially expressed miRNAs corresponding to 155 down-regulated candidate mRNAs and 7 down-regulated differentially expressed miRNAs corresponding to 238 up-regulated candidate mRNAs were constructed.(4)Twenty-four genes related to ferroptosis were screened out from the differential genes.Finally,12 networks were constructed(miR-98-5p/PTGS2,miR-23b-3p/PTGS2,miR-425-5p/TFRC,miR-133a-3p/TFRC,miR-185-5p/TFRC,miR-23b-3p/NFE2L2,miR-23b-3p/LAMP2,miR-98-5p/LAMP2,miR-182-5p/LAMP2,miR-182-5p/TLR4,miR-23b-3p/ZFP36,and miR-182-5p/ZFP36).These results indicate that Panax notoginseng saponins may regulate osteoblast ferroptosis by regulating the expression of miRNAs derived from osteoclast exosomes,thus providing a new idea for the study of the mechanism of steroid-induced femoral head necrosis.

Background Noise-induced hearing loss (NIHL) is a prevalent occupational health problem in workplace settings, with non-steady noise exposure being particularly widespread. Although kurtosis-adjusted equivalent sound level (\begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document}) methods based on linear regression are available to assess hearing damage, the complexity of kurtosis effects necessitates introducing new metrics through nonlinear regression to improve predictive accuracy for hearing loss from non-steady noise exposure. Objective To examine the adjustment terms [\begin{document}$ \mathrm{lg}(\beta _{N}/{\beta }_{G}) $\end{document}] and coefficients (λ) of \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document} using nonlinear regression and evaluate the method’s effectiveness in assessing occupational hearing loss associated with non-steady noise exposure. Methods A cross-sectional study design was employed, enrolling 1034 manufacturing workers and evaluating noise exposure to estimate hearing loss metrics. Quantile regression analysis quantified the proportional contributions of influencing factors for noise-induced permanent threshold shift at 3, 4, and 6 kHz frequencies (NIPTS₃₄₆). \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document} was computed using multiple linear regression and nonlinear least squares optimization. Paired t-tests analyzed predictive efficacy before and after kurtosis adjustment to evaluate its impact on ISO 1999 NIPTS₃₄₆ predictions. Chow tests compared the similarity of logistic regression curves for high-frequency noise-induced hearing loss (HFNIHL) incidence between non-steady noise (\begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document}) and steady noise (\begin{document}$ {{L}}_{\text{EX,}\text{8}\text{ h}} $\end{document}), thereby validating the effectiveness of \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document}. Results The quantile regression analysis showed that kurtosis was a significant indicator of occupational hearing loss risk from non-steady noise (contribution rate was 27.5%, P<0.05). The linear regression and nonlinear least squares methods obtained six different combinations of coefficients (λ) and adjustment terms [\begin{document}$ \mathrm{lg}(\beta _{N}/{\beta }_{G}) $\end{document}]. Incorporating these \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document} adjustments into the ISO 1999 predictive model significantly reduced NIPTS underestimation (from 14.2 dB HL with \begin{document}$ {{L}}_{\text{EX,}\text{8}\text{ h}} $\end{document} to 11.5–5.6 dB HL with \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document}, P < 0.001). The model \begin{document}$ {{{L'}}_{\text{EX,}\text{8}\text{ h}\text{,6}}=L}_{\mathrm{E}\mathrm{X},8\;\mathrm{h}}+7.9\mathrm{lg}({{\beta }_{N}}/{10}) $\end{document} achieved the most significant improvement, reducing underestimation by 8.7 dB HL. The logistic curve analysis further demonstrated that all \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document} dose-response relationships for non-steady noise aligned more closely with the steady noise group than \begin{document}$ {{L}}_{\text{EX,}\text{8}\text{ h}} $\end{document}, with \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}\text{,6}} $\end{document} showing the smallest divergence (difference: 4.1%). Conclusions \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document} demonstrates superior efficacy in assessing the risk of occupational hearing loss induced by non-steady noise exposure. The \begin{document}$ {{L'}}_{\text{EX,}\text{8}\text{ h}} $\end{document} metric, constructed by calculating adjustment terms and coefficients through nonlinear regression analysis, exhibits greater effectiveness than linear regression methods in evaluating occupational hearing loss associated with non-steady noise exposure.

background Current assessment of noise-induced hearing loss relies on the hearing threshold statistical distribution table of ISO 7029-2017 standard (ISO 7029), which is based on foreign population data and lacks a hearing threshold distribution table derived from pure-tone audiometry data of the Chinese population, hindering accurate evaluation of hearing loss in this group. Objective To establish a statistical distribution table of hearing threshold level (HTL) for otologically normal Chinese adults and to provide a scientific basis for revising the diagnostic criteria of occupational noise-induced deafness in China. Methods A total of 1271 otologically normal Chinese adults aged 18-60 years were divided into four groups with 10-year age intervals. Based on the pure tone audiometry data and power function operation formula, the relevant parameters of the median and percentile calculation formula of ISO 7029 were adjusted. Based on the adjusted parameters, a statistical distribution table of HTL of normal Chinese adults in otology was preliminarily constructed according to the calculation formula of ISO 7029. A nonparametric rank sum test was used to compare the difference between the adjusted median deviation value and the ISO 7029 calculation. Results Except for a few frequencies (2000, 3000, and 8000 Hz), the value of parameter α adjusted for the auditory threshold deviation of the Chinese population (α_CHN-md) increased with the increase of frequency, while the value of parameter β adjusted for the auditory threshold deviation of the Chinese population (β_CHN-md) decreased with the increase of frequency. The preliminary distribution table of otologically normal Chinese adults' median hearing threshold deviation (ΔH_CHN-md) showed that the hearing threshold deviation increased with age and frequency. At 8000 Hz, the increase in ΔH_CHN-md with age was the greatest for both men and women, from 0 dB to 23 dB and 21 dB respectively. The minimal threshold elevation was noted at 500, 1000, and 2000 Hz, which increased from 0 dB to 2 dB. In otologically normal Chinese adults, the maximum increase of ΔH_CHN-md with frequency was observed at age of 50 years, which increased from 2 dB at 500 Hz to 23 dB at 8000 Hz in men and from 2 dB at 500 Hz to 21 dB at 8000 Hz in women. The comparison results with the ISO 7029 calculation showed that the trend was consistent. The median hearing threshold deviation value of the adjusted Chinese population was lower than that of the ISO 7029 calculation (ΔH_md). However, they had no significant statistical difference (P>0.05). For otologically normal normal Chinese men and women, the maximum difference of ΔH_md between the 50-year-old group and the ISO calculation at 8000 Hz was 7 dB and 9 dB, respectively. Conclusion This preliminary analysis of hearing threshold deviations in otologically normal Chinese adults suggests that current standards may potentially underestimate hearing loss at frequencies below 8000 Hz while possibly overestimating it at 8000 Hz. These findings require further validation through expanded sample sizes to more accurately assess the characteristics of hearing thresholds in the Chinese population and their discrepancies with existing standards.