Bone repair remains an important target in tissue engineering, making the development of bioactive scaffolds for effective bone defect repair a critical objective. In this study, β-tricalcium phosphate (β-TCP) scaffolds incorporated with processed pyritum decoction (PPD) were fabricated using three-dimensional (3D) printing-assisted freeze-casting. The produced composite scaffolds were evaluated for their mechanical strength, physicochemical properties, biocompatibility, in vitro pro-angiogenic activity, and in vivo efficacy in repairing rabbit femoral defects. They not only demonstrated excellent physicochemical properties, enhanced mechanical strength, and good biosafety but also significantly promoted the proliferation, migration, and aggregation of pro-angiogenic human umbilical vein endothelial cells (HUVECs). In vivo studies revealed that all scaffold groups facilitated osteogenesis at the bone defect site, with the β-TCP scaffolds loaded with PPD markedly enhancing the expression of neurogenic locus Notch homolog protein 1 (Notch1), vascular endothelial growth factor (VEGF), bone morphogenetic protein-2 (BMP-2), and osteopontin (OPN). Overall, the scaffolds developed in this study exhibited strong angiogenic and osteogenic capabilities both in vitro and in vivo. The incorporation of PPD notably promoted the angiogenic-osteogenic coupling, thereby accelerating bone repair, which suggests that PPD is a promising material for bone repair and that the PPD/β-TCP scaffolds hold great potential as a bone graft alternative.
Calcium Phosphates/chemistry* ; Animals ; Bone Regeneration ; Rabbits ; Tissue Scaffolds ; Printing, Three-Dimensional ; Humans ; Human Umbilical Vein Endothelial Cells ; Neovascularization, Physiologic ; Osteogenesis ; Tissue Engineering/methods* ; Biomimetic Materials ; Cell Proliferation ; Angiogenesis

Objective To investigate the prevalence and risk factors of work-related musculoskeletal disorders (WMSDs) among construction workers. Methods A total of 5 783 workers were selected as participants from 12 construction companies in Guangdong Province, Guangxi Zhuang Autonomous Region and Zhejiang Province using a convenient sampling method. The revised Musculoskeletal Disorders Questionnaire was used to investigate the prevalence and influencing factors of WMSDs. Results The prevalence of WMSDs was 27.4% among the construction workers. The prevalence of WMSDs in shoulder, neck, waist/lower back and hand/wrist was 10.6%, 9.5%, 9.5% and 9.4% respectively, which was higher than that in other body parts. Bianry logistic regression analysis showed that the risk of WMSDs in construction workers with junior high school education and below was higher than that of high school/ college and above (P<0.05). The risk of WMSDs was higher in drinkers than that in non-drinkers (P<0.01). The worse the health status of construction workers, the higher the risk of WMSDs (P<0.01). The risk of WMSDs in those who exercised once or twice a month was lower than that in those who did not exercise (P<0.05). The risk of WMSDs was higher in construction workers with longer working hours in uncomfortable postures and greater back bending amplitude at work (all P<0.01). The risk of WMSDs in construction workers with hands holding above the shoulder was higher than that with hands below the shoulder (P<0.05). Construction workers who repeated the same work daily, involved in high-temperature work, often worked overtime, had insufficient rest time, and had a shortage of department personnel had a relatively high risk of WMSDs (all P<0.01). Conclusion The prevalence of WMSDs among the construction workers was relatively high, and the most common WMSDs occurred in shoulder, neck, waist/lower back and hand/wrist. Individual characteristic, work type, work posture and work organization are the influencing factors of WMSDs. Comprehensive measures, especially ergonomic measures based on personal and occupational characteristics should be taken to reduce the risk of WMSDs among construction workers.

Objective To analyze the effect of hand transmitted vibration on fingertip thermotactile perception threshold (TPT) among grinding workers in a sports equipment manufacturing enterprise. Methods A total of 151 male grinding workers from a sports equipment manufacturing enterprise in Guangdong Province were enrolled in the vibration exposure group, and 51 male workers without hand-transmitted vibration exposure were enrolled in the control group, using the judgment sampling method. Basic health conditions of the workers were surveyed in both groups. The TPTs of the distal phalanges of the index and little fingers on both hands were tested using an HVLab thermal perception tester. Results The detection rates of finger numbness and tingling among workers in the vibration exposure group were higher than those in the control group (92.1% vs 7.8% and 59.6% vs 0.0%, respectively, both P<0.01). The detection rates of numbness or tingling of different fingers in the vibration exposure group descended in the following order: index finger, middle finger, ring finger, thumb and little finger. The hot threshold of the index finger and little finger increased (all P<0.01), while the cold threshold decreased (all P<0.01) in the vibration exposure group, compared with the control group. The results of generalized linear regression analysis showed that with the increase of the duration of hand-transmitted vibration, the hot threshold of the index finger and the little finger of both hands increased (all P<0.01), and the cold threshold decreased (all P<0.01). The hot thresholds of workers with numbness of both the index fingers and left little finger were higher than those of workers without numbness of the same finger (all P<0.05). The hot threshold of workers with tingling of the left index finger was higher than those without tingling (P<0.05). The cold thresholds of workers with tingling of the both index fingers and left little finger were lower than those without tingling of the same finger (all P<0.05). The hot threshold of the right little finger increased with age (P<0.01), while the cold thresholds of both little fingers decreased with age (all P<0.01). Conclusion Hand-transmitted vibration exposure increases fingertip hot threshold and decreases fingertip cold threshold of workers exposed to hand-transmitted vibration. Years of service in hand-transmitted vibration work, finger numbness or tingling, and age were influencing factors of TPT. Fingertip TPT examination can be used to assist in the early detection of vibration-induced nerve injury in workers exposed to hand-transmitted vibration.

ObjectiveTo analyze the spectrum distribution characteristics of high-intensity productive noise in key industries in Guangdong Province. Methods A total of 2 806 enterprises in 21 prefecture-level cities in Guangdong Province were selected as the study subjects using the stratified sampling method. On-site investigations were conducted in workplaces. Noise in workplaces and work-sites, and the noise spectrum of the workplaces with sound pressure level ≥85.0 dB(A) were detected. Results The noise of a total of 23 076 workplaces and 20 969 work sites from 30 key industries were monitored. The median (M) and 25th and 75th percentiles (P₂₅, P₇₅) of workplace sound pressure level were 82.3 (78.6, 86.5) dB(A). The rate of the noise exceeded national standard was 30.4%. The sound pressure level M (P₂₅, P₇₅) of work-site was 78.6 (70.0, 83.5) dB(A). The rate of the noise exceeded national standard was 18.0%. Workplace noise and work site noise were positively correlated (Spearman correlation coefficient=0.86, P<0.01). The rate of the noise exceeded national standard was 46.5% in key work sites where the rate of noise exceeded the national standard was ≥25.0%, and corresponding rate of the workplace noise exceeded national standard was 58.1%. The noise spectrum result of 5 636 workplaces sound pressure level>85.0 dB(A) showed that most of the noise source was from grinding machines (441 cases), and the highest average sound pressure level of noise source was from screening machines [93.0 dB(A)]. Cluster analysis results showed that the main noise sources could be divided into three categories, including wideband noise with levels >80.0 dB in all frequency bands except 8 000.0 Hz, medium-high-frequency noise with the highest sound pressure level at 1 000.0, 2 000.0, and 4 000.0 Hz and low frequencies <75.0 dB, and medium-low-frequency noise below 500.0 Hz with sound pressure level >85.0 dB. Conclusion The rate of the noise exceeded national standard in workplace of key industries in Guangdong Province is high, involving a wide range of industries, with high sound pressure levels and obvious spectrum characteristics of corresponding noise sources. Corresponding noise control strategies can be formulated based on different spectrum characteristics and magnitudes.

Objective:To observe the clinical effect of subretinal injection and intravitreal injection of conbercept in the treatment of polypoid choroidal vasculopathy (PCV).Methods:A prospective, randomized double-blind controlled study. From June 2022 to January 2023, 35 patients of 35 eyes with PCV diagnosed at Affiliated Eye Hospital of Nanchang University were included in the study. All patients were first-time recipients of treatment. Best corrected visual acuity (BCVA), optical coherence tomography (OCT), and indocyanine green angiography (ICGA) were performed in all affected eyes. BCVA was performed using an international standard visual acuity chart and converted to logarithmic minimum resolved angle (logMAR) visual acuity for statistical purposes. Enhanced depth imaging with OCT instrument was used to measure the macular retinal thickness (MRT), subfoveal choroidal thickness (SFCT), and pigment epithelium detachment (PED) height. Randomized numerical table method was used to divide the patients into subretinal injection group (group A) and vitreous cavity injection group (Group B), 18 cases with 18 eyes and 17 cases with 17 eyes, respectively. Comparison of age ( t=0.090), disease duration ( t=-0.370), logMAR BCVA ( t=?0.190), MRT ( t=0.860), SFCT ( t=0.247), and PED height ( t=?0.520) between the two groups showed no statistically significant difference ( P>0.05). The eyes of group A were given one subretinal injection of 10 mg/ml conbercept 0.05 ml (containing conbercept 0.5 mg), and subsequently administered on demand (PRN); eyes in group B were given intravitreal injection of 10 mg/ml conbercept 0.05 ml (containing conbercept 0.5 mg). The treatment regimen was 3+PRN. Lesions were categorized into active and quiescent according to the results of post-treatment OCT and BCVA. Active lesions were treated with intravitreal injection of conbercept at the same dose as before; stationary lesions were followed up for observation. BCVA and OCT were performed at 1, 2, 3, 6 and 9 months after treatment; ICGA was performed at 3, 6 and 9 months. BCVA, MRT, SFCT, and PED height changes before and after treatment were compared and observed in the affected eyes of the two groups. Independent sample t-test was used to compare between the two groups. Results:With the prolongation of time after treatment, the BCVA of the affected eyes in groups A and B gradually increased, and the MRT, SFCT, and PED height gradually decreased. Compared with group B, at 2, 3, 6, and 9 months after treatment, the BCVA of group A was significantly improved, and the difference was statistically significant ( t=?2.215, ?2.820, ?2.559, ?4.051; P<0.05); at 1, 2, 3, 6, and 9 months after treatment, the MRT of the affected eyes in group A ( t=?2.439, ?3.091, ?3.099, ?3.665, ?5.494), SFCT ( t=?3.370, ?3.058, ?3.268, ?4.220, ?4.121), and PED height ( t=?3.460, ?4.678, ?4.956, ?5.368, ?6.396) were significantly reduced, and the differences were statistically significant ( P<0.05). No complications such as intraocular inflammation, high intraocular pressure, or vitreous hemorrhage occurred in any of the affected eyes during or after treatment. Conclusion:Compared with the intravitreal injection of conbercept, the subretinal injection of conbercept can more effectively reduce the height of MRT, SFCT, PED height, and improve the visual acuity of the affected eyes with PCV.

Cerebral ischemia-reperfusion injury(CIRI)is a serious complication caused by the recovery of blood flow in the affected brain tissue of patients with ischemic stroke.CIRI patients are often accompanied by neurological dysfunction,cognitive impairment,emotional disorders and other symptoms,which have a serious impact on daily life.At present,CIRI is easy to be diagnosed early,but there are relatively few related specific treatments.In this paper,the correlation between cyclic adenylate-activated exchange protein 1/RAS-related protein 1(Epac1/Rap1)signaling pathway and CIRI is reviewed,in order to provide new ideas for clinical treatment of CIRI patients.

Objective: To analyze the status of noise hazard in workplace of key industries in Guangdong Province. Methods: A total of 1 061 enterprises from 14 key industries in 21 prefecture-level cities in Guangdong Province were selected as the research subjects using stratified sampling method. The occupational health survey was carried out, and the noise intensity in the workplace was detected. Results: There were 12 606 workplaces and 5 570 work sites involved among 1 061 enterprises. The median and the 0-100th percentile value ［M (P₀-P₁₀₀)］ of noise intensity in workplace were 82.6 (46.5-112.6) dB(A), and 35.03% of the workplace exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in workplace were in the northern part of Guangdong and the stone processing industry respectively. The M (P₀-P₁₀₀) of noise intensity in the work sites was 83.7 (47.5-106.2) dB(A), and 36.00% of the work sites exceeded the national noise intensity standard. The regions and industry with the highest rate of noise exceeded the national noise intensity standard in work sites were in the Pearl River Delta region and the ferrous metal mining and dressing industry respectively. The rate of noise protection facilities setting was 66.45%, and the validity of personal protection was 61.73%. The occupational medical examination was performed in 73.24% of the research subjects, and 3.25% of the result was abnormal. The industry with the highest occupational medical examination rate was nonferrous metal smelting and rolling processing, and the industry with the highest abnormal rate of occupational medical examination was stone processing industry. Conclusion: Noise hazards in workplaces of key industries in Guangdong Province are relatively severe, necessitating strengthened supervision and management, noise control measures, and efforts to reduce noise exposure levels in workplaces and work sites.

At present, there is still a big gap between China and developed countries in the field of high-end medical devices, and the ability of independent innovation needs to be improved. In order to comprehensively cultivate innovative talents in the field of medical devices and promote the development of the field of medical devices, the biomedical engineering major of Chongqing Medical University has put forward a "Trinity" innovative talent training system in the field of medical devices, including the teaching of theoretical knowledge, the improvement of practical skills and the guarantee of the innovation system, and established a four stage curriculum system framework of "Perception-Understanding-Enlightenment-Challenge" to form a characteristic course with ultrasonic treatment equipment as the main line. After three years of practice, the results of this training mode show that the innovative ability, professional connotation construction quality and employment postgraduate entrance examination rate of our college students have been steadily improved. The exploration of this talent training mode has reference significance for the cultivation of innovative talents in the field of medical devices in higher medical colleges and universities in China.

Background Wearing anti-vibration gloves is a simple and effective way to prevent hand-arm vibration disease. The requirements for vibration damping gloves are varied by types of operations exposed to vibration. Objective To study the vibration attenuation and dexterity of different types of protective gloves, and to provide reference for scientific wearing of vibration damping gloves for people working with vibration exposure. Methods Nine kinds of common protective gloves (A and B were dipping gloves; C, D, and E were rubber gloves; F and G were textile and fabric gloves; H was cotton gloves; I was leather gloves) used by workers exposed to vibration in 28 factories in Guangdong Province were selected as research objects by typical case sampling method, and the basic parameters of included protective gloves were investigated and measured. According to ISO 10819:2013, a glove vibration transmissibility (GVT) test system was used to detect the vibration transmissibility values and analyze vibration attenuation characteristics of the subjects wearing different protective gloves. The dexterity was tested by Minnesota Manual Dexterity Test. Pearson test was used to analyze the correlations among glove thickness, vibration transmissibility, dexterity score, and grip strength score. Results For rubber gloves (C, D, and E), the associated average adjusted vibration transmissibility at middle and low frequencies \begin{document}$ {\overline T _{\text{M}}} $\end{document} and average adjusted vibration transmissibility at high frequency \begin{document}$ {\overline T _{\text{H}}} $\end{document} were lower than those of other gloves (0.89-0.91 and 0.59-0.80 respectively), the vibration transmissibility values of 50-200 Hz frequency band was 0.81-0.97, and the vibration transmissibility values of 315-1250 Hz frequency band decreased with the increase of frequency (the minimum value was 0.13). For other types of gloves (A, B, F, G, H, and I), the \begin{document}$ {\overline T _{\text{M}}} $\end{document} and \begin{document}$ {\overline T _{\text{H}}} $\end{document} were 0.95-0.98 and 1.03-1.11 respectively, the vibration transmissibility values of 50-200 Hz frequency band was 0.96-1.02, and the vibration transmissibility values of 400-1250 Hz frequency band increased (the maximum value was 1.29). The \begin{document}$ {\overline T _{\text{M}}} $\end{document}, \begin{document}$ {\overline T _{\text{H}}} $\end{document}, and vibration transmissibility values of 40-1250 Hz frequency band of rubber gloves with double-layer protective materials (C, D, and E) were significantly lower than those of gloves with single-layer protective materials. But the \begin{document}$ {\overline T _{\text{M}}} $\end{document} and \begin{document}$ {\overline T _{\text{H}}} $\end{document} of gloves of other types with double-layer materials (F, H, and I) were still greater than 0.9 and 1.0 respectively. Compared with single-layer protective materials, the gloves of other types with double-layer materials showed no significant changes in the vibration transmissibility values of 25-200 frequency band (0.91-1.06), and an increase in the vibration transmissibility values of 250-630 Hz frequency band (the maximum value was 1.22). The dexterity scores and grip strength scores of dipping gloves (A and B) were the lowest. Rubber gloves C had the highest dexterity score and grip strength score. The thickness of protective gloves was negatively correlated with the vibration transmissibility values, and positively correlated with the dexterity score and the grip strength score (P < 0.05). The vibration transmissibility value was negatively correlated with the dexterity score and the grip strength score (P < 0.05). Conclusion Among the 9 kinds of gloves, cotton gloves and leather gloves have no damping effect. Rubber gloves have certain vibration reduction effect, and the vibration reduction effect on high frequency band is better than that on low frequency band. The thicker the damping material is, the better the damping effect is, but the less the dexterity is. Appropriate damping gloves should be selected according to actual vibration operations.

OBJECTIVE: To analyze the characteristics of noise hazard in a nuclear power station. METHODS: The workplaces and working posts which exposed to occupational noise from two 1 000 MW power units in one nuclear power station in Guangdong Province was selected as study subjects using the convenience sampling method. Occupational health survey, noise measurement in the workplace and personal noise dosage measurement were used to monitor noise exposure, and to analyze the characteristics of occupational noise in the nuclear power station. RESULTS: The noise sources of the nuclear power plant were mainly distributed in the nuclear island, conventional island, and peripheral workshops. A total of 237 points of noise intensity were measured in the workplace. The intensity of noise ranged from 66.0 to 99.6 dB(A). The noise intensity in 62.4%(148/237) of points was equal or greater than 80.0 dB(A) and 34.2%(81/237) equal or greater than 85.0 dB(A). The percentage of detection points with noise intensity was equal or greater than 85.0 dB(A) from low to high were nuclear island, conventional island, and peripheral workshops with 22.0%, 37.5% and 53.8% respectively(P<0.01). The personal noise intensity of three positions including inspectors of operation department, preparation and main engine positions of mechanical department exceeded the occupational exposure limit(OEL), and the percentage of positions whose noise intensity exceeded the OEL was 9.7%(3/31). CONCLUSION: High-intensity noise sources of the nuclear power plant are widely distributed in the workshop areas of nuclear island, conventional island, and peripheral workshops. The noise level of some positions exceeded the standards of noise intensity. The prevention and control measures of noise hazards in posts with excessive noise should be strengthened.