Syphilis among middle-aged female sex workers in China: a three-site cross-sectional study.

ObjectivesThis study addresses the lack of empirical studies about the epidemic of syphilis among middle-aged female sex workers (FSWs). The objectives of this study were to investigate prevalence of syphilis, and its potential risk factors among middle-aged FSWs in China.DesignA cross-sectional study with respondent-driven sampling (RDS).SettingA multisite study conducted at three Chinese cites (Nanning, Hefei, and Qingdao) with different levels of sexually transmitted diseases in 2014.Participants1245 middle-aged female sex workers who were over 35 years old (about 400 per study site).Main outcome measuresUnprotected commercial sex, and syphilis and HIV infection were biologically tested and measured.ResultsThe RDS-adjusted prevalence of active syphilis was 17.3% in Hefei, 9.9% in Qingdao, and 5.4% in Nanning. The RDS-adjusted prevalence of prevalent syphilis was between 6.8% and 33.6% in the three cities. The proportion of unprotected sex in the past 48 h verified by the prostate-specific antigen test (PSA) was between 27.8% and 42.4%. Multiple log-binomial regression analyses indicate that middle-aged FSWs who had 5 or more clients in the past week prior to interviews and engaged in unprotected sex were more likely to be active syphilitic cases. Middle-aged FSWs who had rural residency were less likely to be active syphilitic cases.ConclusionsIn contrast with previous studies that reported low prevalence of syphilis and high prevalence of protected sex among FSWs in China, both the prevalence of syphilis and unprotected sex were high among middle-aged FSWs. Evidence-based intervention programmes should be developed and evaluated among this vulnerable population in China and other countries with similar settings

Boosting activity and selectivity of glycerol oxidation over platinum–palladium–silver electrocatalysts via surface engineering

A series of platinum–palladium–silver nanoparticles with tunable structures were synthesized for glycerol electro-oxidation in both alkaline and acidic solutions. Electrochemical results indicate that the catalysts show superior activity in alkaline solutions relative to acidic solutions. In alkaline solutions, the peak current densities of ammonia-etched samples are approximately twice those of saturated-NaCl-etched samples. Ammonia-etched platinum–palladium–silver (PtPd@Ag-NH3) exhibits a peak current density of 9.16 mA cm−2, which is 18.7 and 10 times those of the Pt/C and Pd/C, respectively. The product distribution was analyzed by high performance liquid chromatography. Seven products including oxalic acid, tartronic acid, glyoxylic acid, glyceric acid (GLA), glyceraldehyde (GALD), glycolic acid, and dihydroxyacetone (DHA) were detected. The NH3·H2O etched samples tend to generate more GALD, while the NaCl etched samples have a great potential to produce DHA. The addition of Pd atoms can facilitate glycerol oxidation pathway towards the direction of GALD generation. The Pt@Ag-NaCl possesses the largest DHA selectivity of 79.09% at 1.3 V, while the Pt@Ag-NH3 exhibits the largest GLA selectivity of 45.01% at 0.5 V. The PtPd@Ag-NH3 exhibits the largest C3/C2 ratio of 17.45. The selectivity and product distribution of glycerol electro-oxidation can be tuned by engineering the surface atoms of the as-synthesized catalysts

Exceptional Performance of Hierarchical Ni-Fe (hydr)oxide@NiCu Electrocatalysts for Water Splitting

Developing low‐cost bifunctional electrocatalysts with superior activity for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is of great importance for the widespread application of the water splitting technique. In this work, using earth‐abundant transition metals (i.e., nickel, iron, and copper), 3D hierarchical nanoarchitectures, consisting of ultrathin Ni–Fe layered‐double‐hydroxide (Ni–Fe LDH) nanosheets or porous Ni–Fe oxides (NiFeOx) assembled to a metallic NiCu alloy, are delicately constructed. In alkaline solution, the as‐prepared Ni–Fe LDH@NiCu possesses outstanding OER activity, achieving a current density of 10 mA cm−2 at an overpotential of 218 mV, which is smaller than that of RuO2 catalyst (249 mV). In contrast, the resulting NiFeOx@NiCu exhibits better HER activity, yielding a current density of 10 mA cm−2 at an overpotential of 66 mV, which is slightly higher than that of Pt catalyst (53 mV) but superior to all other transition metal (hydr)oxide‐based electrocatalysts. The remarkable activity of the Ni–Fe LDH@NiCu and NiFeOx@NiCu is further demonstrated by a 1.5 V solar‐panel‐powered electrolyzer, resulting in current densities of 10 and 50 mA cm−2 at overpotentials of 293 and 506 mV, respectively. Such performance renders the as‐prepared materials as the best bifunctional electrocatalysts so far

Investigation of epidemiological and clinical characteristics of people infected with SARS-CoV-2 during the second pandemic of COVID-19 in Chengdu, China

ObjectiveThis study investigated the epidemiological and clinical characteristics of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infected patients during the second pandemic of COVID-19 (coronavirus disease of 2019) in Chengdu, China. Furthermore, the differences between first infection and re-infection cases were also compared and analyzed to provide evidence for better prevention and control of SARS-CoV-2 re-infection.MethodsAn anonymous questionnaire survey was conducted using an online platform (wjx.cn) between May 20, 2023 to September 12, 2023.ResultsThis investigation included 62.94% females and 32.97% of them were 18–30 years old. Furthermore, 7.19–17.18% of the participants either did not receive vaccination at all or only received full vaccination, respectively. Moreover, 577 (57.64%) participants were exposed to cluster infection. The clinical manifestations of these patients were mainly mild to moderate; 78.18% of participants had a fever for 1–3 days, while 37.84% indicated a full course of disease for 4–6 days. In addition, 40.66% of the participants had re-infection and 72.97% indicated their first infection approximately five months before. The clinical symptoms of the first SARS-CoV-2 infection were moderate to severe, while re-infection indicated mild to moderate symptoms (the severity of symptoms other than diarrhea and conjunctival congestion had statistically significant differences) (p < 0.05). Moreover, 70.53 and 59.21% of first and re-infection cases had fever durations of 3–5 and 0–2 days, respectively. Whereas 47.91 and 46.40% of first and re-infection cases had a disease course of 7–9 and 4–6 days.ConclusionThe SARS-CoV-2 infected individuals in Chengdu, China, during the second pandemic of COVID-19 had mild clinical symptoms and a short course of disease. Furthermore, compared with the first infection, re-infection cases had mild symptoms, low incidences of complications, short fever duration, and course of disease

Fabrication and mechanical performance of 3D woven basalt fiber composite materials

Three kinds differently structural 3D woven fabrics with the basalt fiber filaments tows as warp and weft yarn were fabricated on common loom by reasonable design. And, three kinds differently structural 3D woven basalt fiber composite materials were obtained with vinyl ester resin as matrix materials and 3D woven fabrics as reinforced materials, by VARTM molding process (vacuum assisted resin transfer molding process). Then, the tensile and bending properties of three kinds differently structural 3D woven basalt fiber composite materials were tested through the universal testing machine. Results were shown that the 3D woven basalt fiber composite materials had excellent mechanical properties, but the different structures of 3D woven fabrics as reinforced materials shown a big difference on mechanical properties. As follows, the modulus of elasticity for tensile and modulus of elasticity for bending of the 3D orthogonal structure basalt fiber composite materials were the greatest, and that of the 3D throughout angle interlocking structure basalt fiber composite materials was the smallest. Meanwhile, the tensile elongation at break of the 3D throughout angle interlocking structure basalt fiber composite materials were the largest and that of the 3D layered angle interlocking structure basalt fiber composite materials was the smallest