The study aimed to compare mechanical properties and surface characteristics of initial and workingaesthetic archwires with their conventional counterparts. High Aesthetic Sentalloy (full rhodium coatingnickel-titanium; Dentsply GAC) represented the initial aesthetic archwires; and FLI TRU-CHROME(labial PTFE-coated stainless steel; RMO) as the working aesthetic archwires; together with theirconventional counterparts were analysed. A three point bending test was conducted using a universaltesting machine (AGS-X SERIES, Shimadzu, Japan) to determine the load-deflection characteristics ofarchwires. Surface hardness was evaluated by Vickers microhardness test (HMV-FA, Shimadzu, Japan).A 3D Optical Surface Texture Analyzer (ALICONA, InfiniteFocus Real3D, Belgium) and a Field EmissionScanning Electron Microscope (FESEM, FEI Quanta 250, USA) were used for surface evaluation.Results showed that load-deflection characteristics of High Aesthetic Sentalloy archwires did not differfrom its control, whereas FLI TRU-CHROME archwires exhibited higher loading and unloading forcesthan its counterpart. No statistically significant difference in surface hardness was found between FLITRU-CHROME and its control archwires. The coating surfaces of both aesthetic archwires were rougherthan the non-coated conventional archwires, with similar roughness between non-coated surface of FLITRU-CHROME archwires and its counterpart. FLI TRU-CHROME archwires showed a distinct coatingthickness but coating layer is undefined in High Aesthetic Sentalloy archwires. In conclusion, the aestheticrhodium coated nickel titanium archwire has similar mechanical properties as control nickel titaniumarchwire without being adversely affected by the addition of the coating layer. The aesthetic coated PTFEstainless steel archwire has higher load response which could be an advantage as rigid wire in workingstage of orthodontic treatment. Based on their performance, their use could be recommended in caseswhere aesthetic aspect is crucial and where the friction aspect is not critical as their surface roughnessvalues increased.

Objective To understand the prevalence of HIV infection and its influencing factors in the premarital physical examination population in Dehong Prefecture, Yunnan Province, 2017. Methods The data of people receiving premarital medical examination was collected, the demographic characteristics was described and the related factors was analyzed by Logistic regression. Results There were 21 875 participants receiving premarital medical examination in Dehong. 98(0.45%) participants were confirmed positive for HIV and male infection rate was 0.47% (52/10 955) and female was 0.42% (46/10 920). Among the 98 patients, 20 patients were infected in the first time, and main route was sexual transmission accounting for 81.63% (80/98). Logistic multivariate regression analysis showed that age, ethnicity and drug use were the influencing factors for premarital couples infecting HIV. The risk of HIV infection in 31-40 and 41-50 years old group was higher than the people under 25 years old group(OR=3.78, 95% CI：1.81-7.89, P<0.001；OR=3.95, 95% CI：1.72-9.08, P=0.001). The infection risk of Dai and Jingpo ethnic group was higher than that of the Han ethnic(OR=1.86, 95% CI：1.06-3.29, P=0.031；OR=3.25, 95% CI：1.81-5.84, P<0.001). The risk of infection among drug users was much higher than non-drug users (OR=926.76, 95% CI：271.65-3 161.71, P<0.001). Conclusion Age, ethnicity, and drug use are influencing factors of HIV infection among premarital couples. Targeted measures need to be taken against risk factors. HIV infection is mainly transmitted by sexual transmission. It can be effectively detected and controlled through premarital medical examination.