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 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 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 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.

OBJECTIVE: To analyze the clinical features and pathogenesis of a fetus with holoprosencephaly. METHODS: The findings of prenatal ultrasonography was reviewed. Following elective abortion, whole exome sequencing (WES) was carried out to identify potential pathogenic variant. Copy number variants (CNVs) of the abortus and its parents were detected by low-depth high-throughput sequencing. The parents were also analyzed by chromosomal karyotyping. RESULTS: Prenatal ultrasound suggested that the fetus had holoprosencephaly. WES revealed that it had approximately 33 Mb deletion at chromosome 13 involving ZIC2, a haploid dose sensitive gene. The results of low-depth high-throughput sequencing confirmed that the fetus carried a de novo 32.32 Mb deletion at 13q31.1-34. Karyotyping analysis has excluded gross chromosomal aberration in both parents. CONCLUSION The fetus was diagnosed with holoprosencephaly, which may be attributable to the 13q31.1-34 deletion involving the ZIC2 gene.
Adult ; Chromosomes, Human, Pair 13 ; genetics ; Female ; Fetus ; Genetic Testing ; Holoprosencephaly ; diagnostic imaging ; genetics ; pathology ; Humans ; Karyotyping ; Male ; Nuclear Proteins ; genetics ; Pregnancy ; Prenatal Diagnosis ; Sequence Deletion ; Transcription Factors ; genetics ; Ultrasonography, Prenatal ; Whole Exome Sequencing

Objective To establish a method for the dissolution determination of ambroxol hydrochloride orally disinegreting tablets. Methods The UV spectrophotometry was used. The detecting wavelength was at 244 nm. The liquid of dissolution was hydrochloride(0.1 mol·L -1). Rotational speed was 50 r·min-1. Results The linearity range was 3.16-28.44 μg·mL-1.The regression equation was Y＝0.024 2X+0.018 3(r＝0.999 3).The RSD of repeatable test was 0.28%.The average recovery of methodology was 100.4% and RSD was 0.77%. Conclusion The method is simple and reliable, and can be used for the dissolution determination of ambroxol hydrochloride orally disinegreting tablets.

BACKGROUND:Subdermal contraceptive implants as a novel contraceptive method have been extensively used worldwide.OBJECTIVE:To review the research progress in the non-biodegradable and biodegradable long-term subdermal contraceptive implants and to explore their advantages and disadvantages.METHODS:A computer-based search of CNKI,Wanfang,and PubMed (1967-2015) was performed by the first author for relevant articles,using the key words of contraceptive implants,non-biodegradable,biodegradable in Chinese and English,respectively.Initially 240 articles were retrieved,and finally 70 articles were included in result analysis.RESULTS AND CONCLUSION:Long-term subdermal contraceptive implants that pass through the local capillaries into the blood circulation system can avoid the gastrointestinal absorption,improve the bioavailability of drugs,and reduce adverse drug reactions.According to the performance,there are two kinds of drug carriers,non-biodegradable and biodegradable.Although non-biodegradable implants have been widely used and the contraceptive effect is excellent,the implants must be removed surgically because they cannot be absorbed or metabolized in the body.Significant efforts have been devoted to developing biodegradable implants because they can degrade at the end of use.However,the utility of some biodegradable polymers as drug carriers in implantable applications has been hampered by their shortcomings,and further study on alternative materials is urgently required.

Objective To analyze the clinical characteristics of patients with presbycusis by using disyllabic mandarin speech test materials (MSTMs).Methods A total of 59 subjects (23 men and 36 women) with presbycusis,from 61 to 84 years old with the average as 71.3±6.7.They were divided into three groups:the mild group (10 subjects),the moderate group (35 subjects)and the severe group (14 subjects)according to the pure tone average (PTA) thresholds at 0.5,1,2 and 4 kHz from the better ear.In addition,11 subjects of elderly persons with normal hearing were used as the control group.All the subjects enrolled in this study could speak Mandarin well in their daily lives.Nine lists of disyllabic mandarin speech test materials were utilized to test speech recognition threshold (SRT) and P-I function for these groups respectively.Results The PTA(51.65±11.98)and SRT (50.98±16.05)from presbycusis group were much higher than the control group(PTA 19.55± 4.55,SRT 18.79± 7.45),while the average slope of the P-I function 2.63％/dB from the presbycusis group was lower than the control group 4.65％/dB (P＜0.01).The SRT of male patients (56.54±17.23) was higher than the females(47.99± 15.63) (P＜0.05).The PTA and SRT in these three groups divided by degrees of hearing loss were higher than the control group obviously.The PTA and SRT had significantly increased as the degree of hearing loss increased.The differences among these groups were significant (P＜0.01).The average slope of P-I function of these three groups divided by degrees of hearing loss (mild group:2.47％/dB,moderate group:2.76％/dB,severe group:2.42％/dB) was smaller than the slopes in the control group which was 4.65 ％/dB (P＜0.01).The average slope of P-I function among these groups had no significant difference (P＞0.05).Conclusion The SRT of patients with presbycusis increased and the SRT of male was higher than the females.The average slope of P-I function decreased and the curve moved to right side and became a gradual curve.As hearing loss became more severe,the SRT rose more apparently.

This article made a historic review on the treatment and diagnosis process of biliary atresia at home and abroad, and analyzed the problems of diagnosis and treatment on biliary atresia. The author points out that there is no registered system in domestic, which results in screening job has been unable to conduct substantive work for many years. The author also puts forward his own views about the postoperative influence factors including the time of Kasai operation, postoperative cholangitis, biliary cirrhosis and other issues, and suggests that improving the prognosis of children with biliary atresia needs the cooperation among national colleagues to work together.

Objective To explore the clinical effect of mifepristone for emergency contraception. Methods All 379 re-productive age women who required emergency contraception were selected to give oral mifepristone and the contracep-tive effectiveness, the adverse reactions and the single impact factor,vaginal bleeding were observed and analyzed. Results The effective rate of mifepristone for emergency contraception was 79.02%,102 cases (26.9%) appeared ad-verse reactions,less than or equal to 30 years old and take drug by several times were the influence factors of adverse reactions, 22 cases (5.8%) appeared vaginal bleeding. Conclusion There is still possibility to appear pregnancy and ad-verse reactions with mifepristone for emergency contraception, we should be to do a good job of follow-up and treat-ment after taking the drugs.