Objective To evaluate the role of distortion product otoacoustic emissions (DPOAE) testing in evaluating early hearing loss among noise-exposed workers. Methods A total of 174 noise-exposed workers in a metal shipbuilding enterprise were selected as the research subjects by the convenience sampling method. Pure tone audiometry (PTA), DPOAE and the level of noise exposure were conducted on the workers. The rank correlation analysis was used to analyze the correlation between DPOAE amplitude and PTA threshold. The multilevel model was used to analyze the effects of gender, age, noise exposure intensity, cumulative noise exposure (CNE), hearing loss classification and PTA threshold on DPOAE results. Results At the frequencies of 0.50, 1.00, 2.00, 3.00, 4.00, 6.00 and 8.00 kHz, the DPOAE amplitude was negatively correlated with the PTA threshold (rank correlation coefficients were -0.12, -0.48, -0.47, -0.18, -0.23, -0.44, -0.19, respectively, all P<0.01). At the most frequencies, DPOAE amplitude was negatively correlated with age and CNE (all P<0.05). The results of multilevel model analysis showed that there were significant differences in DPOAE amplitudes at certain frequencies across gender, age, noise intensity, CNE, and hearing loss classification (all P<0.05). Significant differences in DPOAE responses were found among different CNE and hearing loss groups (all P<0.01). Conclusion DPOAE testing can objectively reflect the hearing status of noise-exposed workers and could be considered for inclusion in routine hearing monitoring to facilitate early detection of noise-induced hearing loss.

Postmenopausal osteoporosis (PMOP) is a chronic metabolic bone disease caused by a decrease in estrogen levels. With the acceleration of population aging process, the public health burden caused by it is becoming increasingly severe. The prevalence rate of osteoporosis in people over 65 years old in China is as high as 32%, which is especially prominent after menopause, which is about 5 times that of elderly men. About 40% of postmenopausal women are at risk of osteoporotic fractures, with a disability rate of up to 50% and a fatality rate of about 20%. The prevention and treatment of osteoporosis has become a major public health issue of global concern, and it is particularly urgent to develop reasonable and effective prevention and treatment programs and explore their scientific basis. Exercise is an important non-drug means for the prevention and treatment of PMOP, it can improve estrogen levels and the expression of bone formation transcription factors, and inhibit the levels of proinflammatory factors and bone resorption markers, macroscopically manifested by the improvement of bone microstructure and bone density. However, the effectiveness of exercise in improving bone mineral density (BMD) remains controversial. Some studies revealed significant changes of bone to mechanical stimulation, while others showed no significant effect of mechanical training, this heterogeneity in bone adapt to mechanical stimulation is particularly evident in postmenopausal women. Although the evidence that a wide range of exercise programs can improve osteoporosis, the optimal solution to address bone mineral loss remains unclear. The most effective exercise type, dosage and personalized adaptation are still being determined. This study will fully consider the differences in gender and hormone levels, searching and screening randomized controlled trials of PubMed, CNKI and other databases regarding exercise improving bone mineral density in women with PMOP. Strictly following the PRISMA guidelines to reviewed and compared the effects of different types of exercise modalities on BMD at different sites in women with PMOP by network Meta-analysis, to provide theoretical guidance to maintain or improve BMD in women with PMOP.

Aim To study the effect of Guben Yanling pills on liver aging in aging mice and the related mech-anism.Methods The mice were randomly divided in-to blank control group,model group,vitamin E group(0.1 g·kg-1)and low,medium and high dose groups(0.59,1.17,2.34 g·kg-1)of Guben Yan-ling pills.The aging mouse model was established by subcutaneous injection of D-galactose(150 mg·kg-1)into the back of neck.At the same time of mod-eling,the corresponding drugs were given by gavage once a day for six weeks.The main organ indexes were calculated.HE staining was used to observe the mor-phology of liver tissue.Colorimetry was used to detect the activity of β-galactosidase in liver.ELISA was used to detect the content of TNF-α,IL-1 β,IL-6,IL-4,IL-10.Western blot was used to detect the protein relative expression level of IKKβ,Iκ Bα,NF-κB p65.Immunofluorescence was used to detect the expression level of NF-κB p65.Results Compared with the blank control group,the organ index of the brain,liv-er,kidney,spleen,and thymus in the model group decreased(P＜0.05,P＜0.01),the activity of β-galactosidase increased(P＜0.01),liver tissue mor-phology and structure were significantly damaged,the content of TNF-α,IL-1 β and IL-6 increased(P＜0.01),the content of IL-4 and IL-10 decreased(P＜0.01),the levels of IKKβ,NF-κB p65 in-creased(P＜0.01),the levels of IKBα decreased(P＜0.01),and the levels of NF-κB p65 in nucleus increased(P＜0.01).Compared with the model group,the organ indexes of brain,liver,kidney,spleen,and thymus in each dose group of Guben Yan-ling pills increased(P＜0.05,P＜0.01),the activity of β-galactosidase decreased(P＜0.01),the morpho-logical and structural damage of liver tissue was signifi-cantly improved,the content of TNF-α,IL-1 β and IL-6 decreased(P＜0.01),the content of IL-4 and IL-10 increased(P＜0.01),the levels of IKKβ,NF-κB p65 decreased(P＜0.01),the levels of IκBα in-creased(P＜0.01),and the levels of NF-κB p65 in nucleus decreased(P＜0.01).Conclusions Guben Yanling pills can antagonize liver aging in mice,and its mechanism may be related to inhibiting the activa-tion of NF-κB signaling pathway in liver,downregulat-ing downstream pro-inflammatory factor levels,upregu-lating anti-inflammatory factor levels,and alleviating inflammation in liver.

Aim To observe the changes in hippocam-pal 2A subunit of N-methyl-D-aspartate receptor(NR2A)before and after the learning and memory training,and then investigate the neuropharmacological effects of NR2A by microinjection of NVP-AAM077(NR2A specific antagonist)into the hippocampal den-teta gyrus,based on the spatial learning and memory behavior paradigm induced by Mirror water maze train-ing.Methods Three-month old SD rats were random-ly divided into the training and non-training group,and the rats in the two groups were randomly divided into control group and NVP-AAM077 group(NVP).The expressions of NR2A,brain-derived neurotrophic factor(BDNF),transcriptional activator 4(ATF4)and eu-karyotic transcription initiation factor 2 α(eIF2α)phosphorylation levels in denteta gyrus were detected by Western blot.Then,integrated stress response in-hibitor ISRIB was microinjected into the dentate gyrus after the NVP,the expression of ATF4 and p-eIF2αlevels,and the spatial memory abilities were detected.Results Compared with non-training,behavioral training promoted the expression of NR2A and BDNF of rats in denteta gyrus,and this effect could be inhibi-ted by NVP,which significantly increased the expres-sion of p-eIF2α and ATF4.Injection of ISRIB into denteta gyrus significantly inhibited the expression of ATF4,and reversed the spatial memory impairment caused by NVP.Conclusion NVP-induced hipp-ocampal dentate gyrus NR2A-mediated spatial learning and memory impairment in rats may be related to hipp-ocampal integrated stress response.

Objective To compare the clinical efficacies of unilateral biportal endoscopy(UBE)technique and percutaneous endoscopic lumbar discectomy(PELD)technique in the treatment of lumbar disc herniation.Methods The clinical data of 149 patients with lumbar disc herniation in our hospital were retrospectively analyzed and divided into the UBE group(n=80)and the PELD group(n=69)according to different surgical methods.The operation time,intraoperative fluoroscopy frequency,intraoperative blood loss,hospital stay,postoperative complications,visual analogue scale(VAS)score,Oswestry disability index(ODI)score,intervertebral disc height and vertebral canal area of the two groups were compared.Results The operation time in the UBE group was longer than that in the PELD group,and the intraoperative fluoroscopy frequency was fewer than that in the PELD group,the differences were statistically significant(P<0.001).There was no significant difference in the intraoperative blood loss or hospital stay between the two groups(P>0.05).There was no significant difference in the VAS or ODI scores at each time point between the two groups(P>0.05).There was no significant difference in the intervertebral disc height or vertebral canal area at each time point between the two groups(P>0.05).The postoperative vertebral canal areas of patients in the two groups were greater than those before surgery,and the differences were statistically significant(P<0.05).The incidence of postoperative complications in the UBE group was lower than that in the PELD group,the difference was statistically significant(P<0.05).Conclusion In terms of short-term efficacy,both PELD technique and UBE technique can effectively relieve the symptoms of low back and leg pain caused by lumbar disc herniation,and the UBE technique has longer operation time,but with fewer intraoperative fluoroscopy frequency,and lower incidence of postoperative complications.

Objective To monitor the susceptibility of clinical isolates to antimicrobial agents in tertiary hospitals in major regions of China in 2022.Methods Clinical isolates from 58 hospitals in China were tested for antimicrobial susceptibility using a unified protocol based on disc diffusion method or automated testing systems.Results were interpreted using the 2022 Clinical &Laboratory Standards Institute(CLSI)breakpoints.Results A total of 318 013 clinical isolates were collected from January 1,2022 to December 31,2022,of which 29.5％were gram-positive and 70.5％were gram-negative.The prevalence of methicillin-resistant strains in Staphylococcus aureus,Staphylococcus epidermidis and other coagulase-negative Staphylococcus species(excluding Staphylococcus pseudintermedius and Staphylococcus schleiferi)was 28.3％,76.7％and 77.9％,respectively.Overall,94.0％of MRSA strains were susceptible to trimethoprim-sulfamethoxazole and 90.8％of MRSE strains were susceptible to rifampicin.No vancomycin-resistant strains were found.Enterococcus faecalis showed significantly lower resistance rates to most antimicrobial agents tested than Enterococcus faecium.A few vancomycin-resistant strains were identified in both E.faecalis and E.faecium.The prevalence of penicillin-susceptible Streptococcus pneumoniae was 94.2％in the isolates from children and 95.7％in the isolates from adults.The resistance rate to carbapenems was lower than 13.1％in most Enterobacterales species except for Klebsiella,21.7％-23.1％of which were resistant to carbapenems.Most Enterobacterales isolates were highly susceptible to tigecycline,colistin and polymyxin B,with resistance rates ranging from 0.1％to 13.3％.The prevalence of meropenem-resistant strains decreased from 23.5％in 2019 to 18.0％in 2022 in Pseudomonas aeruginosa,and decreased from 79.0％in 2019 to 72.5％in 2022 in Acinetobacter baumannii.Conclusions The resistance of clinical isolates to the commonly used antimicrobial agents is still increasing in tertiary hospitals.However,the prevalence of important carbapenem-resistant organisms such as carbapenem-resistant K.pneumoniae,P.aeruginosa,and A.baumannii showed a downward trend in recent years.This finding suggests that the strategy of combining antimicrobial resistance surveillance with multidisciplinary concerted action works well in curbing the spread of resistant bacteria.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

AIM To study the chemical constituents from the roots of Pfaffia glomerata(Spreng)Pedersen.METHODS The 95%and the 50%ethanol extract from P.glomerata were isolated and purified by silica gel,D101 macroporous resin,sephadex LH-20,polyamide,ODS,preparative HPLC and recrystallization,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Eighteen compounds were isolated and identified as 1,2,4-benzenetriol(1),polypodine B(2),(-)-syringaresinol-4-O-β-D-glucopyranoside(3),poststerone(4),stachysterone B(5),calonysterone(6),taxisterone(7),makisterone C(8),20,22-O-(R-ethylidene)-20-hydroxyecdysone(9),20,22-O-(R-3-methoxycarbonyl)propylidene-20-hydroxyecdysone(10),shidasterone(11),5α-20-hydroxy-ecdysone(12),abutasterone(13),25-hydroxydacryhainansterone(14),methyl-α-D-fructofuranoside(15),methyl-β-D-fructofuranoside(16),chikusetsusaponin Ⅳamethyl ester(17),uridine(18).CONCLUSION Compounds 1-6,8-16,18 are isolated from P.glomerata for the first time,and compounds 1,3-6,8-16,18 are isolated from the genus of Pfaffia for the first time.

AIM To study the chemical constituents from the ethyl acetate fraction of Baccharis trimera(Less.)DC.METHODS The ethyl acetate fraction of B.trimera was isolated and purified by macroporous resin D101,Sephadex LH-20 gel,silica gel and other chromatographic techniques,then the structures of obtained compounds were identified by physicochemical properties and spectral data.RESULTS Twenty-three compounds were isolated and identified as 15,16-epoxy-15α-methoxy-ent-clerod-3-en-18-oic acid(1),13-epi-15,16-epoxy-15α-methoxy-ent-clerod-3-en-18-oic acid(2),methyltrineracetal(3),epimethyltrineracetal(4),trinerolide(5),15-epitrinerolide(6),18-methylmalonyl-7α-hydroxy-meth-yltrineracetal(7),18-methylmalonyl-7α-hydroxy-epimethyltriner-acetal(8),18-methylmalonyl-methyltrineracetal(9),18-methylmalonyl-epi-methyltrineracetal(10),methy 3,5-dicaffeoylquinate(11),8-dimetho-xyflavone(12),4',7-dihydroxy-5-methoxyflavanone(13),4-(3',4'-dihydroxycinna-moyl)-oxy-methy-lcinnamate(14),3',7-dihydroxy-4',6,8-trimethoxy-flavone(15),erigeroflavanone(16),nepetin(17),4,2',4',β-tetrahydroxy-6'-methoxy-α,β-dihydrochalcone(18),eugeniyl-O-β-D-glucoside(19),7-hydroxyl-5,6,3',4'-tetramethoxylflavone(20),phomoxanthone J(21),18-acetyl-7α-hydroxy-methyltrineracetal(22),18-acetyl-7α-hydroxy-epimethyltrineracetal(23).CONCLUSION Compounds 3-10 and 22-23 are epimers isolated from this plant for the first time.Compounds 11-16,18-21 are first isolated from genus Baccharis.

Objective To develop a GIS-based 3D playback system for the flight human-plane data to realize the fusion of pilots'airborne flight data and physiological data.Methods The 3D playback system was developed with the Browser/Server(B/S)architecture,micro-server model,Java language and Spring Cloud technology framework,which was composed of three functional modules for flight process reproduction,physiological situational awareness and critical event calibration analysis.Results The system developed achieved time synchronization and data fusion of airborne flight data and physiological data with a time synchronization frequency of 1 Hz and a refresh rate of not less than 120 frames/s.Conclusion The system developed with high safety,stability,reliability and accuracy facilitates pilot in-flight physiological monitoring and fusion and simultaneous display of airborne flight data and physiological data,which can be used as an important platform for decision-making support in flight training.[Chinese Medical Equipment Journal,2024,45(10):14-19]