Cassie State Stability and Gas Restoration Capability of Superhydrophobic Surfaces with Truncated Cone-Shaped Pillars.

The gas layer stability on superhydrophobic surfaces and gas restoration on the immersed superhydrophobic surfaces have been great challenges for their practical applications in recent years. Inspired by the naturally existing mushroom-like super-repellent superhydrophobic patterns, we choose superhydrophobic surfaces with truncated cone-shaped pillars as our research objects to tackle such challenges by tuning their geometrical parameters. We perform molecular dynamics simulations to investigate the Cassie-Wenzel transition under external pressure and the Wenzel-Cassie transition due to underwater spreading of compressed bubbles. Theories based on the Young-Laplace equation and total free-energy variation are developed to explore the influence of geometrical parameters of pillars on the pressure resistance and underwater gas restoration, which is in good agreement with simulation results. These simulation results and theoretical analysis suggest that cork-shaped pillars, analogous to the surface structures of natural organisms like springtails and Salvinia leaves, can be super-repellent to the liquid and favorable for the gas spreading process. Our study provides theoretical guidance for the design of superhydrophobic surfaces with both Cassie state stability and gas restoration capability.

Contact tracing of syphilis-seropositive pregnant women and syphilis-infection among their male partners in Bao'an district, Shenzhen, China.

BACKGROUND: Untreated male partners are a critical source of maternal re-infection. Contact tracing is a good way to identify infection among partners and reduce risk of mother-to-child transmission related to maternal re-infection. This study aimed to analyze the current situation and related factors of contact tracing of syphilis-seropositive pregnant women and syphilis-infection among their male partners. METHOD: Data of syphilis-seropositive pregnant women and their male partners attending clinic for syphilis-screening were obtained from the Shenzhen Program for Prevention of Congenital Syphilis. Contact tracing rate of syphilis-seropositive pregnant women and syphilis prevalence among male partners were counted, and related factors were also analyzed using a random-effects logistic regression model. RESULT: Of the 1299 syphilis-seropositive pregnant women, 74.1% (963/1299) had their male partners receiving syphilis-screening and 19.1% (184/963) of male partners were syphilis-infected. For pregnant women, being divorced (adjusted odds ratio [AOR] =0.39; 95%CI: 0.17-0.87), seeking for emergency services at their first antenatal clinics visits (AOR = 0.58; 95%CI: 0.44-0.77), reporting willingness to notify partner(AOR = 7.65; 95%CI: 4.69-12.49), multi-partners (AOR = 1.38; 95%CI:1.03-1.86) and having a history of drug abuse (AOR = 0.37; 95%CI: 0.14-1.00)were independently associated with successful contact tracing. For male partners, of minority ethnicity (AOR = 4.15; 95%CI: 1.66-10.34), age at first sex>20(AOR = 0.57; 95%CI: 0.37-0.87), reporting multi-partners (AOR = 1.60; 95%CI: 1.04-2.46), having a history of drug abuse (AOR = 4.07; 95%CI: 1.31-12.64) were independently associated with syphilis-infection. In addition, pregnant women with TRUST titer ≥1:8 (AOR = 2.81; 95%CI: 1.87-4.21), having a history of adverse pregnancy outcomes (AOR = 1.70; 95%CI: 1.14-2.53), reporting multi-partners (AOR = 0.43; 95%CI: 0.29-0.64) and reporting the current partner as the source of syphilis (AOR = 5.05; 95%CI: 2.82-9.03) were independently associated with partners' syphilis-infection. CONCLUSION: Contact tracing is feasible and effective in identifying syphilis-infected partners among syphilis-seropositive pregnant women. Contact tracing is associated with many factors such as women's marital status, services at their first antenatal clinics visit and willingness of partner notification. Partners' ethnicity, age at first sex, multi-partners and history of drug abuse as well as women's levels of TRUST titer were associated with partners' syphilis-infection.

Chlamydia trachomatis infection among patients attending sexual and reproductive health clinics: A cross-sectional study in Bao'an District, Shenzhen, China.

This study aimed to estimate the prevalence of chlamydial trachomatis (CT) infection and explore its risk factors among patients attending sexual and reproductive health clinics in Shenzhen, China. We collected demographic and clinical information from attendees (aged 18-49). CT and Neisseria gonorrhoeae (NG) infection was determined by nucleic acid amplification test (NAAT) on self-collected urine specimens. Of 1,938 participants recruited, 10.3% (95% confidence interval [CI]: 9.6%-11.0%) tested positive for CT. Prevalence was similar between men (10.6% [85/804]; 95% CI, 9.5%-11.7%) and women (10.1% [115/1134]; 95% CI: 9.2%-11.0%). Being 18-25 years old (adjusted odds ratio [aOR] = 2.52; 95%CI:1.35-4.71), never tested for CT before (aOR = 2.42; 95%CI: 1.05-5.61) and infected with NG(aOR = 3.87; 95%CI: 2.10-7.10) were independently associated with CT infection. We found that CT infection is prevalent among patients attending sexual and reproductive health clinics in Shenzhen, China. A comprehensive program including CT screening, surveillance and treatment is urgently needed.