BACKGROUND:The healing of mandibular fractures after rigid internal fixation is influenced by many factors,including the material of the bone plate,fracture site,and bone density of the patient.However,there are relatively few studies on the relationship between the stability of mandibular fracture fixation in different bone qualities and they lack a scientific basis. OBJECTIVE:To analyze the stability of fixation of mandibular fractures with different bone qualities with bioabsorbable plates and miniature titanium plates by finite element analysis. METHODS:Three-dimensional finite element models of class Ⅰ-Ⅳ mandibular fractures were developed according to the bone quality classification method proposed by ZARB and LEKHOLM.The fractures at the median mandibular symphysis,mandibular body,and mandibular angle were simulated under different bone qualities.Bioabsorbable bone grafting plates(or miniature titanium plates)were placed at each fracture site for fixation and to simulate the state of healthy side occlusion.Finite element analysis on the model was used to analyze the relative displacement of the fracture segments and the stress distribution of fixators. RESULTS AND CONCLUSION:(1)The maximum stress value during fixation with titanium plates increased gradually with the increase of bone class,in which the maximum stress value of titanium plates was the highest in the mandibular body class Ⅳ bone group,which was 382.74 MPa and 96.11 MPa in the miniature titanium plate and bioabsorbable plate groups.The results for mandibles of the same bone type showed that the maximum stress value of titanium plates was much higher than that of bioabsorbable plates.(2)For fractures of the median middle of the mandible in types Ⅲ and Ⅳ,the displacement of the fracture breaks at the fixation site was large and exceeded the limiting value of bone healing(>150 μm),regardless of whether the fixation was performed with a miniature titanium plate or a bioabsorbable plate.For type Ⅳ mandibular fractures,the fracture end displacement in the bioabsorbable plate group exceeded the healing limit value,and the fracture end displacement in the miniature titanium plate group was close to the healing limit value.Under the same bone quality and fracture site,the fracture displacement of the miniature titanium plate group was smaller than that of the bioabsorbable plate group.(3)The results showed that the strength and stiffness of the two internal fixations were sufficient to support bone healing of fractures at three sites of the types Ⅰ-Ⅳ mandible,and the fixation stability of the bioabsorbable plate was almost the same as that of the miniature titanium plate,which could provide early healing conditions for fractures.Mandibular bone type should be taken into consideration in the treatment of mandibular fracture.The higher the mandibular bone grade,the worse the stability of fracture fixation,and the more likely the complications such as poor bone healing will occur after surgery.

The aim of this paper was to investigate the serotypes,virulence factors and drug resist-ance of clinical isolates of Pasteurella rnultocida of porcine origin in recent years.Morphological screening and polymerase chain reaction(PCR)were used to isolate and identify 119 isolates from nasal swabs and lung tissue samples sent from swine farms in Zhejiang Province from 2010 to 2024.The isolates of Pasteurella multocida were subjected to capsular polysaccharide serotyping,lipopolysaccharide serotyping,virulence factor detection and drug resistance analysis by PCR and Kirby-Bauer disc agar diffusion method(K-B).The results showed that there were 64 strains(53.7％)of A-type,54 strains(45.3％)of D-type and 1 strain(0.9％)of F-type among the capsu-lar polysaccharide serotypes,and 10 strains(8.4％)of L1-type,20 strains(16.8％)of L3-type,86 strains(72.2％)of L6-type,and 3 strains(2.6％)of undetermined type among the lipopolysaccha-ride serotypes.The amplification results of 10 virulence genes showed that the detection rate of virulence genes hgbA,higbB and fimA was over 86.0％,the detection rate of toxA was 8.4％,while the virulence gene tbpA was not detected.There were also differences in the distribution vir-ulence genes in different capsular polysaccharide serotypes.Virulence factor pfhA was detected in type A and F but not in type D.The detection rate of adhesin gene tadD in serotype A(92.2％)was significantly higher than that of type D(9.3％),and,on the contrary,the detection rate of ad-hesin gene hsf-l in serotype D(90.7％)was significantly higher than that of type A(20.3％).Drug resistance analysis revealed that Pasteurella multocida showed high susceptibility to antimi-crobial drugs such as amoxicillin,ampicillin,cephalosporins,doxycycline,fosfenicol and ciprofloxa-cin,and showed strong resistance to antimicrobial drugs such as lincomycin,cotrimoxazole,genta-micin and amikacin,and there were 54 multi-drug resistant strains(78.3％).In summary,capsular polysaccharide serotypes were dominated by type A and D,lipopolysaccharide serotypes were dom-inated by L6,the distribution of some virulence genes varied greatly among different serotypes,and the proportion of multi-resistant strains was high,which provide reference for the prevention and control of this disease.

The aim of this paper was to investigate the serotypes,virulence factors and drug resist-ance of clinical isolates of Pasteurella rnultocida of porcine origin in recent years.Morphological screening and polymerase chain reaction(PCR)were used to isolate and identify 119 isolates from nasal swabs and lung tissue samples sent from swine farms in Zhejiang Province from 2010 to 2024.The isolates of Pasteurella multocida were subjected to capsular polysaccharide serotyping,lipopolysaccharide serotyping,virulence factor detection and drug resistance analysis by PCR and Kirby-Bauer disc agar diffusion method(K-B).The results showed that there were 64 strains(53.7％)of A-type,54 strains(45.3％)of D-type and 1 strain(0.9％)of F-type among the capsu-lar polysaccharide serotypes,and 10 strains(8.4％)of L1-type,20 strains(16.8％)of L3-type,86 strains(72.2％)of L6-type,and 3 strains(2.6％)of undetermined type among the lipopolysaccha-ride serotypes.The amplification results of 10 virulence genes showed that the detection rate of virulence genes hgbA,higbB and fimA was over 86.0％,the detection rate of toxA was 8.4％,while the virulence gene tbpA was not detected.There were also differences in the distribution vir-ulence genes in different capsular polysaccharide serotypes.Virulence factor pfhA was detected in type A and F but not in type D.The detection rate of adhesin gene tadD in serotype A(92.2％)was significantly higher than that of type D(9.3％),and,on the contrary,the detection rate of ad-hesin gene hsf-l in serotype D(90.7％)was significantly higher than that of type A(20.3％).Drug resistance analysis revealed that Pasteurella multocida showed high susceptibility to antimi-crobial drugs such as amoxicillin,ampicillin,cephalosporins,doxycycline,fosfenicol and ciprofloxa-cin,and showed strong resistance to antimicrobial drugs such as lincomycin,cotrimoxazole,genta-micin and amikacin,and there were 54 multi-drug resistant strains(78.3％).In summary,capsular polysaccharide serotypes were dominated by type A and D,lipopolysaccharide serotypes were dom-inated by L6,the distribution of some virulence genes varied greatly among different serotypes,and the proportion of multi-resistant strains was high,which provide reference for the prevention and control of this disease.

Objective Nowadays, radioactive xenon isotopes, including ^131mXe, ^133mXe, ¹³³Xe, and ¹³⁵Xe, are primarily released into the atmosphere through various reactor operation and major accidents of reactors. To improve the online monitoring capability of xenon in nuclear facilities and their gaseous effluents, a highly sensitive online xenon monitoring system was developed to monitor, warn, and alarm the activity concentration of radioactive xenon. Methods The online monitoring system for radioactive xenon gas in nuclear facilities was established using xenon membrane separation and concentration, xenon high-efficiency selective adsorption, and low-background gamma-ray spectrometry analysis methods. Results Under the operation mode of one-hour sampling and one-hour measuring, the minimum detectable activity concentration of the radioactive xenon online monitoring system for ¹³³Xe was approximately (1.43 ± 0.03) Bq/m³. Conclusion This system can be effectively used for online monitoring of xenon activity concentration in nuclear facilities such as nuclear power plants and isotope production reactors, as well as in gaseous effluents. It helps improve the safety level of personnel, the environment, and nuclear facilities.

Objective To design a mobile personnel radiation protection equipment for operation in environments with high radiation such as spent fuel reprocessing plants, to achieve simultaneous protection against γ radiation, neutron radiation, and radioactive aerosol, to reduce the internal and external exposure dose of radioactive workers, and to meet the requirement of operation for two hours. Methods The core parts of the mobile personnel radiation protection equipment included a shielding chamber and a respiratory maintenance system. An automated chassis was used for the movement and lifting of the shielding chamber. MCNP software was used to simulate and calculate the protective effects of shielding chamber made of different materials and material thicknesses. Experimental verification of the shielding chamber design was conducted. Mathematical models were established to describe the variations in the content of various gases in the chamber with personnel operation time. A respiratory maintenance system, a harmful gas absorption device, and an automated mobile chassis were designed. Results The shielding chamber made of polyethylene with a thickness of 80 mm achieved an 80% neutron shielding rate. The respiratory maintenance system could support workers for 2 hours of operation inside the equipment. The mobile chassis allowed operation of the equipment with one person. Conclusion This mobile personnel radiation protection equipment can solve the problem in simultaneous protection against γ radiation, neutron radiation, and radioactive aerosol. The equipment can provide radiation protection for radioactive workers, reduce exposure dose, and reduce personnel burden. This system provides technical means for the operation and maintenance of equipment in high-radiation sites such as spent fuel reprocessing plants.

Objective To address the radioactive contamination of wounds caused by transuranic nuclides, wound radiation imaging based on coded aperture imaging technology was investigated. Methods By simulating multiple source terms using Monte Carlo method, the differences in imaging performance between two image reconstruction algorithms under near-field conditions were compared. The effects of detector pixels and detection plane pixels on image resolution were investigated. Results The imaging system was simulated based on the designed dimensions. The simulated imaging field of view was 89.4 mm × 89.4 mm and the simulated angular resolution was 1.98°. Based on the comparison of the average width at half height of the reconstructed point sources under different conditions, it was found that increasing the number of pixels in the detector and detection plane optimized the angular resolution but significantly prolonged the Monte Carlo simulation time. Conclusion According to the simulation results, the parameters of the imaging system can be used to effectively image radioactive contamination. Our results provide methodological support for the measurement of wound contamination caused by transuranic nuclides, and lay the foundation for the development of wound contamination imaging detection systems in the future.

Objective To investigate the separation efficiency of three physical separation methods for gaseous ¹⁴C, namely membrane separation, adsorption separation, and low-temperature separation, to screen for the optimal separation method, and to provide a reference for the separation and enrichment of ¹⁴CO₂ in online monitoring of ¹⁴C. Methods The experimental plan was designed, and three devices were constructed for separation and purification experiments. The purity, recovery rate, and separation time of CO₂ separated by the three methods were analyzed. Results All the three methods achieved the separation of CO₂. Under certain conditions, 20 mL of sample gas was obtained. The separation time of membrane separation method was 0.5 hour, CO₂ gas with a sample purity of 0.0486%-0.0488%VOL was obtained, and the recovery rate was only 2.5%−12.7%. The separation time of MOF material adsorption separation method was 24−30 hours, CO₂ gas with a sample purity of 20.2%−47.5%VOL was obtained, and the recovery rate was 57.3%−63.2%. The separation time of low-temperature separation method was 3 hours, CO₂ gas with a sample purity of 96.0%−99.8%VOL was obtained, and the recovery rate was 81.5%−92.5%. Conclusion The purity and recovery rate of CO₂ with low-temperature separation method were higher compared to membrane separation method and MOF material adsorption separation method. The separation time of low-temperature separation method was moderate. The low-temperature separation method can provide a reference for the enrichment technology of ¹⁴C in the rapid measurement of gaseous ¹⁴C effluent.

Inflammatory bowel disease (IBD) is a formidable disease due to its complex pathogenesis. Macrophages, as a major immune cell population in IBD, are crucial for gut homeostasis. However, it is still unveiled how macrophages modulate IBD. Here, we found that LIM domain only 7 (LMO7) was downregulated in pro-inflammatory macrophages, and that LMO7 directly degraded 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) through K48-mediated ubiquitination in macrophages. As an enzyme that regulates glycolysis, PFKFB3 degradation led to the glycolytic process inhibition in macrophages, which in turn inhibited macrophage activation and ultimately attenuated murine colitis. Moreover, we demonstrated that PFKFB3 was required for histone demethylase Jumonji domain-containing protein 3 (JMJD3) expression, thereby inhibiting the protein level of trimethylation of histone H3 on lysine 27 (H3K27me3). Overall, our results indicated the LMO7/PFKFB3/JMJD3 axis is essential for modulating macrophage function and IBD pathogenesis. Targeting LMO7 or macrophage metabolism could potentially be an effective strategy for treating inflammatory diseases.

Flavonoid glycosides are the main active constituents of Epimedii Folium and its related plants. They can be divided into polyglycosides and low glycosides according to the number of glycosyl group. The polyglycosides of Epimedii Folium can be transformed into low glycosides after biotransformation ；pharmacological activities of low glycosides in anti-tumor ，tonifying kidney yang and anti-osteoporosis are stronger than those of polyglycosides. In this paper ， the research progress about biotransformation technology of flavonoid glycosides of Epimedii Folium was reviewed. It was found that the main biotransformation pathway of flavonoid glycosides of Epimedii Folium was to obtain low glycosides by removing glycosyl group ； related methods were mainly enzymatic hydrolysis and microbial transformation ，and also included plant cell transformation ，acid hydrolysis method and synthesis method.

Objective:To provide references for standardizing the post-operative aeromedical assessment of heart valve disease of flying personnel by analyzing the pathogenesis characteristics and treatment.Methods:The case data of flying personnel with heart valve disease hospitalized in Air Force Medical Center from November of 2010 to December of 2021 were collected, which was called the clinical group; the relevant cases of heart valve disease in domestic flying personnel reported in the literature were retrieved, which was called the literature group. The retrospective study was carried out and the data was analyzed according to the aircraft type, lesion location, treatment method and identification results.Results:There were 20 cases in the clinical group. According to the number of detected cases, the valve positions order was the aortic valve (12 cases), the mitral valve (7 cases), the tricuspid valve (4 cases, all concomitant), and the pulmonary valve (1 case). The literature group had 11 cases, mainly were aortic valve disease (10 cases) and tricuspid valve (1 case). Most of these aortic valve lesions were based on the pathology of bicuspid aortic valve (BAV). Among the cases of aortic valve disease, 12 cases were flight-qualified, 1 case was restricted flight, 1 case of fighter aircraft was transferred to fly transporter, 3 cases were temporary unqualified for flight, 3 cases were unqualified for flight, and 2 cases were waivered. Among the cases of mitral valve disease, 3 cases were flight-qualified, 4 cases were temporary unqualified for flight, 1 case of tricuspid valve and 1 case of pulmonary valve were qualified for flight.Conclusions:The lesion site of valve is the main factor influencing the aeromedical assessment result. The aortic valve is the most common site of valve disease among flying personnel, and BAV is the most common pathologic type. It should be strengthened physical examination identification and prevention.