Community-engaged mHealth intervention to increase uptake of HIV pre-exposure prophylaxis (PrEP) among gay, bisexual and other men who have sex with men in China: study protocol for a pilot randomised controlled trial

INTRODUCTION: The large number of key populations in China who would benefit from HIV pre-exposure prophylaxis (PrEP) in the context of limited health system capacity and public awareness will pose challenges for timely PrEP scale-up, suggesting an urgent need for innovative and accessible interventions. This study aims to develop and pilot test a theory-informed, tailored mobile phone intervention that was codeveloped by young gay men, HIV clinicians and public health researchers to increase engagement in PrEP education and initiation among Chinese gay, bisexual and other men who have sex with men (GBMSM), who bear a disproportionate burden of HIV infections and remain underserved in the healthcare system. METHODS AND ANALYSIS: This two-phase study includes a formative assessment using in-depth interviews (N=30) and a 12-week experimental pilot study using a two-arm randomised controlled trial design (N=70). The primary intervention is delivered through a WeChat-based mini-app (a program built into a Chinese multipurpose social media application) developed by young GBMSM from a 2019 crowdsourcing hackathon. Using mixed methods, we will further investigate the specific needs and concerns among GBMSM in terms of using PrEP as an HIV prevention strategy, how their concerns and PrEP use behaviours may change with exposure to the mini-app intervention during the study period and how we can further refine this intervention tool to better meet GBMSM's needs for broader implementation. ETHICS AND DISSEMINATION: This study and its protocols have been reviewed and approved by the Institutional Review Boards of the University of North Carolina at Chapel Hill, USA (19-3481), the Guangdong Provincial Dermatology Hospital, China (2020031) and the Guangzhou Eighth People's Hospital, China (202022155). Study staff will work with local GBMSM community-based organisations to disseminate the study results to participants and the community via social media, workshops and journal publications. TRIAL REGISTRATION NUMBER: The study was prospectively registered on clinicaltrials.gov (NCT04426656) on 11 June 2020

Novel stereoselective synthesis of (<i>E</i>)-cinnamonitriles via Heck arylation of acrylonitrile catalysed by a silica-supported bidentate arsine palladium(0) complex

( E)-Cinnamonitriles have been synthesised stereoselectively in high yields via Heck arylation of acrylonitrile with aryl iodides catalysed by a silica-supported bidentate arsine palladium(0) complex. This polymeric palladium(0) complex can be recovered and reused without noticeable loss of activity. </jats:p

Superior Comprehensive Mechanical Properties of a Low-Carbon Medium Manganese Steel for Replacing AISI 4330 Steel in the Oil and Gas Industry

A low-carbon medium manganese steel (0.12C-3.13Mn) containing Cr, Ni, Mo, V, and Cu elements was designed to replace the AISI 4330 steel applied in the oil and gas industry. The mechanical properties, microstructures, and fatigue crack growth rate were comparatively analyzed using uniaxial tension tests, microstructure characterization, and compact tension with fatigue crack growth characterization. The results showed that the ductility and −40 °C impact energy of 0.12C-3.13Mn steel were better than AISI 4330 steel (from 115 J to 179 J), while the yield strength of 957 MPa of the former was lower than the latter of 1060 MPa after being subjected to the same tempering process. The microstructure of 0.12C-3.13Mn steel was composed of a mixture of tempered martensite, reversed austenite, and nanosized precipitation particles, while the microstructure of S4330 steel contained ferrite and large-size Fe3C with lath and near-spherical morphologies. Compared to Cr-rich Fe3C, (V, Mo)C and Cu-rich particles have smaller sizes and, thus, provide more strengthening increment, leading to a higher yield ratio. The impressive fatigue-resistance property was obtained in 0.12C-3.13Mn steel because the threshold value was 5.23 MPa*m1/2 compared to the value of 4.88 MPa*m1/2 for S4330 steel. Even if the fatigue crack grew, the stress intensity factor range of 0.12C-3.13Mn steel was obviously wider than that of AISI 4330 steel due to the presence of reversed austenite and secondary cracks. Overall, the AISI 4330 steel could be replaced with the designed 0.12C-3.13Mn steel due to the similar strength and better ductility, low-temperature toughness, and fatigue-resistance property

Superior Comprehensive Mechanical Properties of a Low-Carbon Medium Manganese Steel for Replacing AISI 4330 Steel in the Oil and Gas Industry

A low-carbon medium manganese steel (0.12C-3.13Mn) containing Cr, Ni, Mo, V, and Cu elements was designed to replace the AISI 4330 steel applied in the oil and gas industry. The mechanical properties, microstructures, and fatigue crack growth rate were comparatively analyzed using uniaxial tension tests, microstructure characterization, and compact tension with fatigue crack growth characterization. The results showed that the ductility and −40 °C impact energy of 0.12C-3.13Mn steel were better than AISI 4330 steel (from 115 J to 179 J), while the yield strength of 957 MPa of the former was lower than the latter of 1060 MPa after being subjected to the same tempering process. The microstructure of 0.12C-3.13Mn steel was composed of a mixture of tempered martensite, reversed austenite, and nanosized precipitation particles, while the microstructure of S4330 steel contained ferrite and large-size Fe3C with lath and near-spherical morphologies. Compared to Cr-rich Fe3C, (V, Mo)C and Cu-rich particles have smaller sizes and, thus, provide more strengthening increment, leading to a higher yield ratio. The impressive fatigue-resistance property was obtained in 0.12C-3.13Mn steel because the threshold value was 5.23 MPa*m1/2 compared to the value of 4.88 MPa*m1/2 for S4330 steel. Even if the fatigue crack grew, the stress intensity factor range of 0.12C-3.13Mn steel was obviously wider than that of AISI 4330 steel due to the presence of reversed austenite and secondary cracks. Overall, the AISI 4330 steel could be replaced with the designed 0.12C-3.13Mn steel due to the similar strength and better ductility, low-temperature toughness, and fatigue-resistance property.</jats:p

Effect of Mn Content on the Toughness and Plasticity of Hot-Rolled High-Carbon Medium Manganese Steel

The tensile and impact deformation behavior of three different Mn content test steels, xMn-1.0C-0.25V-1.5Cr-0.3Mo (5, 8 and 13 wt%), were investigated using mechanical properties testing, SEM-EBSD and TEM. The elongation and &minus;20 &deg;C impact energy of the three types of Mn content test steels increased as the Mn content increased. The room temperature tensile elongation was 9%, 23% and 81%, and the &minus;20 &deg;C impact energy was 9 J, 99 J and 241 J, respectively. The fracture morphologies of 5 Mn and 8 Mn were found to be cleavage fractures with secondary cracks and micro-voids. The 13 Mn fracture morphology was a plastic fracture with many coarse dimples. Transverse cracks perpendicular to the tensile direction occurred on the surface of the gauge area of 5 Mn and 8 Mn tensile specimens, reducing plasticity dramatically. This was mainly related to the martensitic transformation produced by stress. We characterized the martensite near the tensile fracture and speculated the main mode of crack propagation. Furthermore, a little amount of sharp-shaped BCC phase was found in the 5 Mn, which was determined to be a hard phase relative to the austenite matrix by nanoindentation test. These steels have stacking fault energies ranging from ~15 to ~29 mJ/m2 with increasing Mn content 13 Mn has high stacking fault energy (SFE) and austenite stability. Twin-induced plasticity (TWIP) was the deformation mechanism

Energy self-supply automobile exhaust gas circulation processing device

Abstract Aiming at the energy waste caused by the exhaust emission of about 30%∼40% of the automobile engine energy and the exhaust emission caused by the failure of the three-way catalytic converter to reach the working temperature during the start-up of the automobile, our team proposes a design scheme for energy reuse and exhaust gas treatment of automobile exhaust pipes. The work has the characteristics of simple structure, low cost and strong pertinence, and achieves energy conservation and reduction of air pollution caused by exhaust emissions. The main body of this work consists of an energy conversion system and an exhaust gas circulatory system. Energy conversion system: The heat of the exhaust cylinder wall is reused by the thermoelectric power generation sheet. In order to convert thermal energy into electrical energy with higher efficiency, a heat sink is used to increase the temperature difference between the inside and outside of the thermoelectric power generation chip. The secondary energy utilization can realize the autonomous operation of the exhaust gas circulation system. Exhaust gas circulation system: The system is automatically controlled by single-chip microcomputer STM32F10XX. When the vehicle starts, the automobile exhaust gas would not meet the emission standard. At this time, the exhaust gas is passed into the exhaust gas storage bag, and the temperature of the three-way catalytic converter is monitored by the temperature sensor. When the operating temperature of the three-way catalytic converter is reached, the exhaust passage will be converted by the single-chip microcomputer, and the automobile exhaust gas will be discharged into the air. At the same time, the non- standard exhaust gas in the exhaust gas storage bag is again introduced into the three- way catalytic converter for secondary catalysis by using a micro-extractor. This avoids the situation that the temperature of the three-way catalyst is low and the catalytic efficiency is low, resulting in substandard exhaust emissions.</jats:p

Risk factors and fraction of exhaled nitric oxide in obstructive sleep apnea in adults

Objective This study aimed to evaluate the relationship between obstructive sleep apnea (OSA) and the fraction of exhaled nitric oxide (FENO), and to assess the effect of risk factors of airway inflammation on OSA. Methods Medical records of patients in the Respiratory Sleep Center at Chao-Yang Hospital in Beijing between January 2015 and June 2017 were analyzed. All patients were diagnosed with OSA. Data of the medical history, clinical examinations, FENO, and upper airway computed tomographic findings were collected. Logistic regression was used to evaluate risk factors of OSA. Results A total of 181 patients were admitted to the Respiratory Sleep Center during the study and 170 had a diagnosis of OSA and were included in the study. Single factor analysis showed that male sex, age, body mass index, smoking index, alcohol consumption, FENO, soft palate thickness, soft palate length, the narrowest transverse diameter of the upper airway, tonsil size, and nasal sinusitis were risk factors for sleep-disordered breathing and disease severity. Conclusions Male sex, age, body mass index, FENO, the narrowest transverse diameter of the upper airway, and normal tonsil size are associated with OSA and disease severity. The severity of OSA is associated with FENO levels. </jats:sec

Effect of Mn Content on the Toughness and Plasticity of Hot-Rolled High-Carbon Medium Manganese Steel

The tensile and impact deformation behavior of three different Mn content test steels, xMn-1.0C-0.25V-1.5Cr-0.3Mo (5, 8 and 13 wt%), were investigated using mechanical properties testing, SEM-EBSD and TEM. The elongation and −20 °C impact energy of the three types of Mn content test steels increased as the Mn content increased. The room temperature tensile elongation was 9%, 23% and 81%, and the −20 °C impact energy was 9 J, 99 J and 241 J, respectively. The fracture morphologies of 5 Mn and 8 Mn were found to be cleavage fractures with secondary cracks and micro-voids. The 13 Mn fracture morphology was a plastic fracture with many coarse dimples. Transverse cracks perpendicular to the tensile direction occurred on the surface of the gauge area of 5 Mn and 8 Mn tensile specimens, reducing plasticity dramatically. This was mainly related to the martensitic transformation produced by stress. We characterized the martensite near the tensile fracture and speculated the main mode of crack propagation. Furthermore, a little amount of sharp-shaped BCC phase was found in the 5 Mn, which was determined to be a hard phase relative to the austenite matrix by nanoindentation test. These steels have stacking fault energies ranging from ~15 to ~29 mJ/m2 with increasing Mn content 13 Mn has high stacking fault energy (SFE) and austenite stability. Twin-induced plasticity (TWIP) was the deformation mechanism.</jats:p