Objective:To investigate the incidence of hearing loss among helicopter flying personnel, and to analyze the contributing factors.Methods:Basic data of 443 male helicopter flying personnel who received physical examinations at Beidaihe Rehabilitation and Recuperation Center of PLA between March and June 2024 was collected. The hearing threshold levels were measured at 8 frequencies: 250, 500, 1 000, 2 000, 3 000, 4 000, 6 000 and 8 000 Hz. Routine blood tests and blood biochemical tests were performed. Based on the results of pure-tone audiometry, the participants were divided into 2 groups: the hearing loss group (hearing threshold ≤20 dB HL) and the normal hearing group (hearing threshold >20 dB HL). The basic data, routine blood results, and blood biochemical indicators were compared between the 2 groups before the contributors to hearing loss were analyzed.Results:A total of 443 helicopter flying personnel were included in the study, with 82 cases (18.51%) in the hearing loss group and 361 cases (81.49%) in the normal hearing group. There were significant differences in age and pulse between the flying personnel in the 2 groups ( t=2.13, 2.78, P=0.034, 0.006). Among the blood routine indicators, only the mean platelet volume (MPV) was significantly different ( t=2.26, P=0.025). Among the blood biochemical indicators, only homocysteine (HCY) revealed statistically significant difference ( Z=2.30, P=0.021). The determinants of hearing loss in helicopter flying personnel were age ( OR=1.046, 95% CI: 1.060-1.361), pulse ( OR=1.201, 95% CI: 1.060-1.361), MPV ( OR=1.365, 95% CI: 1.016-1.834) and HCY ( OR=1.065, 95% CI: 1.033-1.097). Conclusions:Age, pulse, the MPV and HCY levels can all contribute to hearing loss, and the MPV and HCY can serve as potential biomarkers for hearing loss in helicopter flying personnel. Potential hearing loss should be detected early and personalized interventions should be implemented. Noise exposure should be monitored more rigorously to reduce the risk of occupational hearing loss for helicopter flying personnel and ensure flight safety.

Objective:To investigate the incidence of hearing loss among helicopter flying personnel, and to analyze the contributing factors.Methods:Basic data of 443 male helicopter flying personnel who received physical examinations at Beidaihe Rehabilitation and Recuperation Center of PLA between March and June 2024 was collected. The hearing threshold levels were measured at 8 frequencies: 250, 500, 1 000, 2 000, 3 000, 4 000, 6 000 and 8 000 Hz. Routine blood tests and blood biochemical tests were performed. Based on the results of pure-tone audiometry, the participants were divided into 2 groups: the hearing loss group (hearing threshold ≤20 dB HL) and the normal hearing group (hearing threshold >20 dB HL). The basic data, routine blood results, and blood biochemical indicators were compared between the 2 groups before the contributors to hearing loss were analyzed.Results:A total of 443 helicopter flying personnel were included in the study, with 82 cases (18.51%) in the hearing loss group and 361 cases (81.49%) in the normal hearing group. There were significant differences in age and pulse between the flying personnel in the 2 groups ( t=2.13, 2.78, P=0.034, 0.006). Among the blood routine indicators, only the mean platelet volume (MPV) was significantly different ( t=2.26, P=0.025). Among the blood biochemical indicators, only homocysteine (HCY) revealed statistically significant difference ( Z=2.30, P=0.021). The determinants of hearing loss in helicopter flying personnel were age ( OR=1.046, 95% CI: 1.060-1.361), pulse ( OR=1.201, 95% CI: 1.060-1.361), MPV ( OR=1.365, 95% CI: 1.016-1.834) and HCY ( OR=1.065, 95% CI: 1.033-1.097). Conclusions:Age, pulse, the MPV and HCY levels can all contribute to hearing loss, and the MPV and HCY can serve as potential biomarkers for hearing loss in helicopter flying personnel. Potential hearing loss should be detected early and personalized interventions should be implemented. Noise exposure should be monitored more rigorously to reduce the risk of occupational hearing loss for helicopter flying personnel and ensure flight safety.

Nowadays, the aging of China's population is becoming increasingly serious, and fertility of women under the national three-child policy is declining, both middle-aged and elderly women and women of childbearing age are facing reproductive health problems. Traditional oral preparations have a short acting time and some varieties have low bioavailability problems, while the long-acting sustained-release preparations have the advantages of convenient use, stable blood drug concentration and higher safety. Their development provides theoretical basis and technical support for the development and application of reproductive contraceptives. In the decades of research, a variety of different drug delivery systems have been born. Among them, the polymer-based membrane-controlled reservoir preparations, as a common drug sustained-release system, is mostly used in reproductive health and has broad market prospects. In this paper, polymer-based membrane-controlled reservoir drug delivery systems in the field of reproductive health was briefly reviewed, and four key issues including polymer material selection, in vitro drug release model, preparation types and research progress, and challenges were discussed, which can provide reference for the development of related contraceptives in the future.

Nowadays, the aging of China's population is becoming increasingly serious, and fertility of women under the national three-child policy is declining, both middle-aged and elderly women and women of childbearing age are facing reproductive health problems. Traditional oral preparations have a short acting time and some varieties have low bioavailability problems, while the long-acting sustained-release preparations have the advantages of convenient use, stable blood drug concentration and higher safety. Their development provides theoretical basis and technical support for the development and application of reproductive contraceptives. In the decades of research, a variety of different drug delivery systems have been born. Among them, the polymer-based membrane-controlled reservoir preparations, as a common drug sustained-release system, is mostly used in reproductive health and has broad market prospects. In this paper, polymer-based membrane-controlled reservoir drug delivery systems in the field of reproductive health was briefly reviewed, and four key issues including polymer material selection, in vitro drug release model, preparation types and research progress, and challenges were discussed, which can provide reference for the development of related contraceptives in the future.

Lack of mucoadhesive properties is the major drawback to poloxamer 407 (F127)-basedhydrogels for mucosal administration. The objective of the present study was to construct a novel mucoadhesive and thermosensitivehydrogel drug delivery system based on an amino-functionalized poloxamer for vaginal administration. First, amino-functionalized poloxamer 407 (F127-NH) was synthesized and characterized with respect to its micellization behavior and interaction with mucin. Then using acetate gossypol (AG) as model drug, AG-loaded F127-NH-basedhydrogels (NFGs) were evaluated with respect to rheology, drug release,vaginal mucosal adhesion,intravaginal retention and local irritation after vaginal administration to healthy female mice. The results show that F127-NHis capable of forming a thermosensitivehydrogel with sustained drug release properties. An interaction between positively charged F127-NHand negatively charged mucin was revealed by changes in the particle size and zeta potential of mucin particles as well as an increase in the complex modulus of NFG caused by mucin.andfluorescence imaging and quantitative analysis of the amount of AG remaining in mouse vaginal lavage all demonstrated greater intravaginal retention of NFG than that of an unmodified F127-basedhydrogel. In conclusion, amino group functionalization confers valuable mucoadhesive properties on poloxamer 407.

Objective To observe the chemical camouflage effects of methoxy polyethylene glycol(mPEG) on like human B antigens on Rhesus monkey red blood cell(rRBC) and to study the safety of transfusion with mPEG modified monkey RBC(mPEG rRBC).Methods rRBC were modified with 3mg/ml mPEG. The rRBC blood group and the effects of mPEG modification on blood conversion were assayed by absorption and elution methods.The structural and functional changes of mPEG rRBC were also tested.The survival fraction of mPEG modified like B rRBC in like A recipient monkey were examined by flow cytometry.The transfusion effects of mPEG modified rRBC on recipient's blood and urine were also observed.Results mPEG have been covalently bound to the surface of Rhesus monkey RBC (like human B blood group),mPEG could cover rRBC like B antigen.Transfusion of mPEG modified like B rRBC to like A Rhesus monkey had no harmful effects on the recipient.Conclusion The present study suggests that transfusion of mPEG modified RBC could be safety in experimental animals