Objective:To design a specialized ultrasound therapeutic device for rabbit urethral scars and to verify its applicability and effectiveness.Methods:New Zealand male rabbits were used as the experimental objects, and the ultrasound therapeutic instrument was customized according to the structure and size of the rabbit penises. The ultrasound therapeutic instrument included the ultrasound pulse emission and control system, the final-stage amplifier, and the ultrasound probe. Firstly, the ultrasound probe was designed according to the size and structure of rabbit penises, and the parameters of the ultrasound probe were determined by COMSOL finite element simulation and actual testing of the sound field distribution. Secondly, the driving circuit of the ultrasound probe was designed according to the parameters of the elements. Then the ultrasound pulse emission and control system based on the field-programmable gate array (FPGA) and the serial screen were designed. Subsequently, the ultrasound therapeutic instrument was subjected to a performance test and a safety test. The ultrasound therapeutic instrument was constructed to include the ultrasound amplifier and the ultrasound probe. Finally, a rabbit urethra reconstruction model was constructed, and eight white rabbits were randomly divided into a model group and an experimental group. The rabbits in the experimental group received the ultrasound therapeutic instrument for treatment of the urethra immediately, with an ultrasound frequency of 2 MHz, a pulse interval of 10 ms, and an output sound intensity of 0.73 W/cm 2. The treatment was performed twice a week (on Tuesday and Thursday), with 10 min of irradiation each time, lasting for four weeks. The rabbits in the model group did not receive any treatment. The area percentage of transforming growth factor-β1 (TGF-β1), matrix metalloproteinase-2 (MMP-2), and tumor necrosis factor-α (TNF-α) staining-positive areas in rabbit urethral tissues were quantitatively analyzed, and the urethral circumference was calculated using Image J software. Results:Due to the addition of sound-absorbing materials, the sound pressure distribution in the treatment chamber was more uniform, and the average value of the standing wave ratio was 1.11, indicating that the structural design met the design requirements. In the overall performance test, the natural focal position of the three ultrasonic transducers was 10 mm, and the consistency of the sound field distribution meet the experimental requirements. The relationship between the peak sound pressure of each transducer and the power supply voltage was close to linear. The output sound intensity ranged from 0.35 to 0.74 W/cm 2, which met the experimental requirements. With the ultrasound output, the temperature of the test point increased slowly, and this experiment could increase the temperature of the tissue by up to 3.3 ℃, which would not lead to thermal damage to the tissue. Animal experiment results showed that the immunopositive area fraction of TGF-β1 in the urethral tissues of rabbits in the experimental group [(4.21 ± 1.32)%] was smaller than that of the model group [(8.53 ± 3.43)%] ( t = ?4.24, P < 0.001). The immunopositive area fraction of TNF-α in the urethral tissues of rabbits in the experimental group [(5.14 ± 2.72)%] was smaller than that of the model group [(7.23 ± 1.57)%] ( t = ?3.37, P < 0.05). The MMP-2 level in the urethral tissue of rabbits in the experimental group [(10.65 ± 2.24)%] was higher than that of the model group[(6.98 ± 2.74)%] ( t = 2.19, P < 0.05). The urethral circumference [(12 209 ± 2 743) μm] was higher than that of the model group [(10 127 ± 2 237) μm] ( t = 15.46, P < 0.05). Conclusions:An ultrasound therapeutic instrument dedicated to rabbit urethral scars has been successfully designed and can be used for the study of ultrasound treatment of rabbit urethral scars.

Objective:To design a fully integrated multi-channel implantable brain-computer interface electrical stimulation system.Methods:The human-computer interaction interface of the upper computer was set by users, and the data was packaged via a self-built protocol. When parameters were transmitted to the field programmable gate array (FPGA) chip through the Bluetooth module, the stimulation chip was controlled after the parameter analysis was completed. Eventually the user-set current stimulation was output. To verify the system feasibility, the accuracy of the single-channel stimulation waveform, the multi-channel output capability, and the adjustable range of the parameter were tested separately.Results:It realized 16 channels of time-sharing differential stimulation current output, the output stimulation current waveform was dual-phase equal-width pulse, the amplitude ranged within 4~1 000 μA, the pulse single-phase width range was 10~1 000 μs, the cycle time was 1~1 000 ms, thus the current parameters could be accurately adjusted.Conclusions:A fully integrated multi-channel implantable brain-computer interface electrical stimulation system was completed.

Objective:To investigate the occupational hazard factors of different industries in Tongliao City, and to provide scientific basis for the prevention and control of occupational disease in Tongliao City.Methods:In July 2021, the detection data of coal dust, silica dust, cement dust, benzene, noise and other occupational hazard factors, as well as the occupational health examination data of workers in various positions of 104 enterprises in different industries in Tongliao City were cllected and anylazed. χ 2 test was used to analyze the results of chest radiography of workers in different age groups. Results:A total of 104 enterprises were investigated, and the median time-weighted average concentration ( CTWA) of coal dust, silic a dust, cement dust and benzene in contact with test posts were 0.94, 0.30, 0.70 and 0.95 mg/m 3, respectively. The median 8 h equivalent sound level ( LEX, 8 h) of noise was 74.1 dB (A) . The over standard rates of silica dust, cement dust and noise contact positions were 10.83% (16/240) , 7.14% (2/28) and 0.48% (3/628) , respectively. The differences of chest X-ray examination of coal dust and silica dust workers in different working ages were statistically significant (χ 2=218.50, 531.80, P<0.001) . The difference of hearing threshold of noise workers with different working age was statistically significant (χ 2=1290.00, P<0.001) . The rates of leukopenia and neutropenia were 41.90% (44/105) and 20.95% (22/105) in benzene exposed workers. The positive rate of brucella exposure workers was 1.33% (1/75) for tiger red plate agglutination test and 3.23% (3/93) for tube agglutination test. Conclusion:Silica dust, cement dust and noise exceed the standard in some posts and places in the Tongliao City, and some workers are infected with Brucella. In the future, we can focus on monitoring noise-generating posts, strengthen supervision and implement prevention and control measures to reduce the incidence of occupational diseases.

Objective:To investigate the occupational hazard factors of different industries in Tongliao City, and to provide scientific basis for the prevention and control of occupational disease in Tongliao City.Methods:In July 2021, the detection data of coal dust, silica dust, cement dust, benzene, noise and other occupational hazard factors, as well as the occupational health examination data of workers in various positions of 104 enterprises in different industries in Tongliao City were cllected and anylazed. χ 2 test was used to analyze the results of chest radiography of workers in different age groups. Results:A total of 104 enterprises were investigated, and the median time-weighted average concentration ( CTWA) of coal dust, silic a dust, cement dust and benzene in contact with test posts were 0.94, 0.30, 0.70 and 0.95 mg/m 3, respectively. The median 8 h equivalent sound level ( LEX, 8 h) of noise was 74.1 dB (A) . The over standard rates of silica dust, cement dust and noise contact positions were 10.83% (16/240) , 7.14% (2/28) and 0.48% (3/628) , respectively. The differences of chest X-ray examination of coal dust and silica dust workers in different working ages were statistically significant (χ 2=218.50, 531.80, P<0.001) . The difference of hearing threshold of noise workers with different working age was statistically significant (χ 2=1290.00, P<0.001) . The rates of leukopenia and neutropenia were 41.90% (44/105) and 20.95% (22/105) in benzene exposed workers. The positive rate of brucella exposure workers was 1.33% (1/75) for tiger red plate agglutination test and 3.23% (3/93) for tube agglutination test. Conclusion:Silica dust, cement dust and noise exceed the standard in some posts and places in the Tongliao City, and some workers are infected with Brucella. In the future, we can focus on monitoring noise-generating posts, strengthen supervision and implement prevention and control measures to reduce the incidence of occupational diseases.