Objective To explore the possibility of the inner vertical outer spiral complex tubular urethra scaffold vascularization in repairing long segment of urethral defect.Methods From August 2014 to October 2015,27 clean male New Zealand white rabbits were divided into 3 groups,S1 group was transfected recombinant vascular endothelial growth factor(VEGF) gene lentiviral vector group.S2 group was vascular pedicle transfer tube group.C group was simple stent group.A 3.0 cm inner vertical outer spiral complex scaffold was constructed by using the small intestine acellular matrix (SIS) and polylactic acid copolymer (PLGA) modified by type Ⅰ collagen surface,and adipose-derived mesenchymal stem cells (ADSC) and smooth muscle cells after transformation from New Zealand white rabbits.In S1 group,the seed cells were transfected by recombinant vascular endothelial growth factor (VEGF) gene lentivirus,which express VEGF protein.The complex scaffold was used to repair 3.0 cm rabbit urethral defect In S2 group,the untransfected cells were seeded into the scaffold and embedded in the skin near the groin artery 3 weeks for repairing urethral defect with vascular pedicle transfer tube.In group C,the unseeded scaffold was used to repair the urethral defect alone.Postoperative observation and urethrography were followed 4,8 and 24 weeks after implantation.The HE staining,fluorescence tracing,immunohistochemical and scanning electron microscopy were evaluated at the same phase.Results In S1 group,there were one urinary fistula and one urethral stricture-related death,respectively.The urethra was smooth and patent,histological examination showed active hyperplasia of urethral capillary.In S2 group,there were one urinary fistula and two urethral stricture-related deaths,respectively.The urethral was rough,local thinning or dilated.Fat accumulation and mucosal contraction were found in the urethral submucosal,respctively.In C group,there were one urinary fistula,three hypospadias,and three urethral stricture-related deaths.The thickness of the urethra was uneven and stricture bending.The urethral mucosa was poorly repaired and the scar was narrow.HE and CD31 staining showed that S1 and S2 groups were active in the proliferation of urethral capillaries,and the angiogenesis was abundant.VEGF staining showed that the cytoplasm of endothelial cell layer,smooth muscle layer of vascular wall and the urothelial epithelial cell layer were fully expressed at 24 weeks,especially in epithelial cell layer.CKpan staining showed that the epithelium of S1 and S2 group developed to stratified epithelium,and the morphology of urethra was similar to normal urethra at 24 weeks.The urethral epithelial in C group of grew poor as single-level,irregular arrangement,24 weeks is still a lack of effective stratified epithelium.HE and oα-SMA staining showed that the smooth muscle and actin gradually increased in group S1 and S2,α-SMA staining in group C was scarce and increased at 24 weeks.PLGA was encapsulated by the surrounding tissue and the structure of electrospinning was clear after 4 weeks,absorbed and degraded after 8 weeks and absorbed after 24 weeks.Conclusions The inner vertical outer spiral comnplex tubular urethra scaffold maybe a reasonable method in repairing long segment urethral defects,and the methods of tubular urethra scaffold vascularization by transfected VEGF gene recombinant lentiviral vector and vascular flap deserve more research.

Objective To investigate the feasibility of measuring femoral neck torsion angle and anteversion angle by laser projection method .Methods The femoral neck torsion angle and anteversion were observed and described .An angle measuring device was designed and produced .With the device , the femoral torsion angle and anteversion angle were measured by laser projection method two times .Statistical analysis was performed on the measured value , and sides difference .Results The differences between femoral neck torsion angle and anteversion angle were observed .There was no significant difference ( P >0.05, power =100%) between the two measurements by laser projection method . Measurements of the femoral anteversion were 13.58 °±6.55 °on the left side , and 12.15 °±5.83 °on the right side . Measurements of the femoral neck torsion angle were 18.50 °±7.38 °on the left and 19.08 °±8.59 °on the right .There was no significant difference between left and right side ( P >0.05 ) .Conclusion The laser projection method is the effective method in measuring femoral neck torsion angle and anteversion angle , and has excellent repeatability .

Objective: To quantitatively compare five occupational health risk assessment models in assessing silica dust hazard risk in small open pits, so as to provide the reference for the research of occupational health risk assessment methodology Methods : Seven small open pits were selected as the evaluation sites. The models from Singapore, the United Kingdom's Control of Substances Hazardous to Health Essentials ( COSHH Essentials ), Australia, Romania, and the International Council on Mining and Metals ( ICMM ) were applied to assessing the occupational health risk of the workers exposed to silica dust. The risk ratios ( RRs ) were calculated, and the parallelism, accuracy and correlation of the evaluation results of the five models were compared. Results : The RRs of the Singaporean model, COSHH model, Romanian model, Australian model and ICMM model were 0.8, 1.0, 0.4, 0.6 and 0.8, respectively. The Singaporean model and the Australian model were able to distinguish transport drivers from sprinkler drivers in the health risk exposed to silica dust, which was consistent with the actual risk of the two posts. Except for COSHH model, the RRs of the other four models were positively correlated ( P<0.05 ); the RRs were all positively correlated with concentration ratios ( CRs ) ( P<0.05 ), and the correlation coefficient between RRs and CRs of the Singaporean model was the largest (0.801). Conclusion Among the five models, the Singaporean model can more accurately evaluate the hazard risk of silica dust in posts of open pits, and has a good correlation with the other models.

Objective To study the correlationship between type Ⅰcollagenα1 (COL1A1) gene polymorphism and the occurrence of osteosarcoma. Methods Peripheral blood from 54 patients with osteosarcoma and 126 normal ones were collected, rs1061970 genotype of COL1A1 gene was amplified with PCR and products were analyzed by pyrosequencing among the samples. Results The allele frequency of TT (13.0%) and CT (48.1%) was significantly higher in pathologi-cal group than that in the normal control group, which manifested a allele frequency of TT(11.9%) and CT(30.2%) (P<0.05). Additionally, allele frequency of T in patients with osteosarcoma was 37.0%, higher than the control group (27.0%), with OR of 1.59 and 0.99-2.57 of 95%CI, with no difference of statistically significant (P>0.05), but the risk was still on the rise of osteosarcoma. Conclusion COL1A1 gene polymorphism may be related with the incidence of osteosarcoma, patients who carry the T allele of gene of COL1A1 may increase the risk of osteosarcoma occurrence.

This paper introduced concepts of occupational health risk grading and its development in China and abroad, reviewed the history of seeking occupational health classification supervision models, and explored the applicability and effectiveness of occupational health risk grading and assessment methods serving occupational health classified supervision on employers. These findings would provide a scientific basis for occupational health classification supervision and law enforcement.

In the face of a serious occupational disease prevention and control situation, the lack of efficient supervision and regulation methods has become a prominent contradiction. This paper reviewed the progress and application of occupational health grading and classification supervision methods for employers in China in recent years, and analyzed the characteristics and limitations of selected methods. The grading and classification supervision methods have gradually developed from considering only inherent health risk of occupational disease hazards, to considering both inherent attributes of occupational disease hazards and exposure duration. Some regional authorities introduced trial measures for grading and classification of occupational health supervision by embracing exposure level of an occupational disease hazard of interest, associated outcome severity, and occupational health management situation of targeted employers. In October 2022, the National Disease Control and Prevention Bureau issued the Notice on Carrying out Pilot Work of Occupational Health Classification Supervision and Law Enforcement, which further promoted the establishment of a differentiated occupational health supervision model. Grading and classification of occupational health supervision can improve the supervision efficiency of public health administration departments and promote employers to fulfill the main responsibility of occupational disease prevention and control.

The National Disease Control and Prevention Bureau and the National Health Commission jointly issued an announcement on Notice on Carrying out Pilot Work of Occupational Health Classification Supervision and Law Enforcement, which presented a method of comprehensive risk assessment method of occupational disease hazards of employers. This method embraces relevant factors at full scale and is simple in operation, but its applicability and accuracy of assessment results need further practical study. Based on the steps of occupational health risk assessment and proven occupational health risk assessment methods available at home and abroad, this paper proposed improvements and discussed the comprehensive risk assessment method of occupational disease hazards of employers, so as to provide a technical basis to implement the occupational disease hazard classification management of employers for relevant government supervision departments.