Objective: To investigate the effects of a Twin-Block appliance combined with slow maxillary expansion (SME) on transverse dental and skeletal parameters in adolescent patients with Angle Class Ⅱ division 1 malocclusion, and to provide a reference for clinical orthodontic practice. Methods: This retrospective study was approved by the Institutional Ethics Committee. A total of 21 adolescents with Class Ⅱ division 1 malocclusion who underwent two-phase treatment with a Twin-Block appliance combined with SME at the Department of Orthodontics, College & Hospital of Stomatology, Guangxi Medical University, in 2021 to 2023 were consecutively enrolled. In the first phase, a functional appliance was used to coordinate the skeletal relationship between the maxilla and mandible by leveraging growth potential. In the second phase, a fixed appliance was employed for fine adjustments of the dental arches based on the specific condition. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T0) and after the first phase of functional correction (T1). Transverse measurements at the first molar region, including molar buccolingual inclination, dental arch width, and basal bone width, were performed using Dolphin 3D Imaging software. Changes between T0 and T1 were statistically analyzed. Results: After the first phase of treatment, the left and right maxillary first molars showed a significant increase in buccal inclination by 5.47° ± 1.38° and 5.35° ± 1.61°, respectively (P<0.001). The arch width in the maxillary first molar region also increased by (2.68 ± 1.14) mm, and the basal bone width increased by (1.14 ± 1.24) mm (all P<0.001). The proportion of skeletal expansion accounted for an average of 42.86%, while dental expansion accounted for 57.14%. No statistically significant changes were observed in any mandibular transverse measurements (all P>0.05). Conclusion In adolescent patients with Angle Class Ⅱ division 1 malocclusion accompanied by maxillary transverse deficiency, Twin-Block appliance combined with SME can effectively expand maxillary dental arch and basal bone width while improving sagittal relationship, thereby correcting transverse discrepancy. The maxillary width changes were predominantly dental.

【Objective】 To study the risk factors of blood donors confirmed to be positive for syphilis, so as to avoid highrisk groups, guide the recruitment of blood donors and improve blood safety. 【Methods】 From September 2021 to August 2022, 44 514 blood samples were screened using two enzyme-linked immunosorbent reagents for syphilis, and the reactive samples were confirmed by TPPA. Blood collection time, blood collection location, blood donation numbers, gender, age, marital status and educational level of blood donors were taken as the prediction risk factors, and factors with statistically significant differences by univariate Logistic regression analysis were further analyzed using multivariate factor Logistic regression analysis to determine the final independent risk factors. 【Results】 A total of 121 syphilis antibody reactive samples were detected by enzyme-linked immunosorbent assay, and 64 were confirmed positive by TPPA. Excluding those with incomplete information, a total of 44 505 blood donors were included in the analysis. Logistic regression analysis showed that there were statistically significant differences in blood collection location, blood donation numbers, age and education level. 【Conclusion】 Based on the analysis results of risk factors of syphilis positive blood donors in Wuhu, it is necessary to strengthen the consultation of blood donors in blood donation sites. The high-risk groups are first-time blood donors over 50 years old, with education level of junior high school or below.

【Objective】 To investigate the confirmatory status of HIV-1 antibody detection and Western blot (WB) test among voluntary blood donors in Wuhu, and to explore the strategies and methods to further ensure blood quality and safety. 【Methods】 Blood samples were preliminarily screened by ELISA and NAT, and the reactive samples were sent to Wuhu CDC for further WB test of HIV-1 antibody. The confirmation results of HIV-1 antibodies of voluntary blood donors in Wuhu in the past 10 years were retrospectively collected. The characteristics of WB bands of positive samples were analyzed, and the demographic characteristics of HIV-infected voluntary blood donors were sorted out. 【Results】 A total of 354 864 blood samples from voluntary blood donors in Wuhu during January 2011 to May 2021 were investigated, among which 42 were confirmed HIV positive (HIV-1 antibody positive in 41, and solo HIV-RNA reactive in 1), with a total HIV positive rate of 11.8/100 000(42/354 864). Statistical differences were found in gender [males 97.6% (41/42) vs females 2.4% (1/42)], marital status [unmarried 17.3/100 000 vs married 8.0/100 000] and occupation [staff/workers 37.5/100 000 vs students11.4/100 000 vs others 7.7/100 000]. Among the positive samples, the yield rate of WB bands gp160 was 100% (41/41), both gp41 and p24 were 97.6% (40/41),, and p55 was the lowest 46.3% (19/41). P51 and P66 presented the highest yield consistency (Kappa=1.000, P<0.05). Four samples were solo HIV-RNA reactive, and one of them was>5 000 cps/mL by viral load (VL) testing, indicating HIV window period infection. 【Conclusion】 HIV infection statistically affected male donors more than females in Wuhu area, and most were early infection that revealed by WB band analysis. NAT plays an important role in the detection and confirmation of HIV infection during the window period, and is essential for blood safety.

【Objective】 To analyze the HIV infection among voluntary blood donors in Wuhu area, so as to provide effective data for improving blood donation recruitment strategies and clinical safe blood use. 【Methods】 All reactive samples from HIV screening among voluntary blood donors in Wuhu from January 2017 to September 2020 were selected and sent to Wuhu CDC for confirmation test.The receiver operating characteristic (ROC) curve was used to compare the accuracy of enzyme-immune reagents. The optimal critical value of ELISA was used to analyze the setting of serological gray area. The preliminary screening S/CO values of confirmed positive, negative and indeterminate samples were compared, and the significance of differences were analyzed by SPSS 22.0 software. 【Results】 75 cases of initially HIV reactive samples were submitted for testing: 17 cases were confirmed positive, 17 indeterminate and 41 negative.The area under curve (AUC) of the 4th generation anti-HIV ELISA reagent was greater than that of the 3rd generation reagent, and the 4th generation reagent was better than the 3rd generation reagent in accuracy. All the 17 confirmed positive samples had high S/CO reactivity with duplicate reagents, and the initial screening S/CO value was significantly higher than that of confirmed negative and indeterminate samples (P<0.05). There was no significant statistical difference in S/CO values between confirmed negative and indeterminate results (P>0.05). 【Conclusion】 Voluntary blood donors in Wuhu is a middle-endemic population for HIV infection. The setting of grey areas for serological testing is of little significance. Blood safety should be further guaranteed through standardized pre-donation interventions, sensitive nucleic acid detection technologies and shared regional data platforms.