Piezoelectric-enhanced photocatalytic performance of porous carbon nitride nanosheets.

Through the utilisation of mechanical energy, piezocatalysis and piezophotocatalysis have emerged as promising strategies to tackle the current energy and environmental issues. In this work, porous graphitic carbon nitride (g-C3N4) nanosheets were synthesised via a novel self-templating process followed by ultrasonic exfoliation to produce materials with a thickness of 1.5-2 nm and a high specific surface area of 59.48 m2/g. Piezo-response force microscopy (PFM) indicated that the as-prepared porous g-C3N4 nanosheets show excellent piezoelectric response. Moreover, the porous g-C3N4 nanosheets exhibit remarkable piezophotocatalytic degradation of Rhodamine B (RhB), showing an optimal first-order rate constant (k = 0.301 min-1) under visible light and ultrasonic co-excitation, which was 2.3 times the value under visible light irradiation alone and 9.7 times the value under only ultrasonic excitation. A piezoelectric field generated by ultrasonic excitation drove photogenerated electrons and holes in opposite directions to migrate towards the surface of the nanosheets, resulting in the generation of more reactive radicals and thereby accelerating RhB degradation. By highlighting the potential of porous g-C3N4 nanosheets as a piezo-semiconductor for environmental remediation applications, this study paves the way for developing a new method for converting solar and mechanical energy via a piezo-mediation photocatalytic reaction.

Piezoelectric Effect Enhanced Photocatalytic Activity of Pt/Bi3.4Gd0.6Ti3O12 Plasmonic Photocatalysis.

Novel Pt/Bi3.4Gd0.6Ti3O12 heterojunction was synthesized by a decoration of Pt nanoparticles (PtNPs) on the surface of piezoelectric Bi3.4Gd0.6Ti3O12 (BGTO) through an impregnation process. The photocatalytic, piezo-catalytic, and piezo-photocatalytic activities of the Pt/BGTO heterojunction for methyl orange (MO) degradation were investigated under ultrasonic excitation and whole spectrum light irradiation. The internal piezoelectric field of BGTO and a plasmonic effect have been proven important for the photocatalytic activity of the heterojunctions. Pt/BGTO exhibited an optimum photocatalytic degradation performance of 92% for MO in 70 min under irradiation of whole light spectrum and ultrasonic coexcitation, and this value was about 1.41 times higher than the degradation rate under whole spectrum light irradiation alone. The PtNPs in Pt/BGTO heterojunction can absorb the incident light intensively, and induce the collective oscillation of surface electrons due to the surface plasmon resonance (SPR) effect, thus generating "hot" electron-hole pairs. The internal piezoelectric field produced in BGTO by ultrasonic can promote the separation of SPR-induced "hot" charge carriers and facilitate the production of highly reactive oxidation radicals, thus enhancing Pt/BGTO heterojunction's photocatalytic activity for oxidizing organic dyes.

Effect of ambient temperature on outpatient admission for osteoarthritis and rheumatoid arthritis in a subtropical Chinese city.

BACKGROUND: Current findings on the impact of weather conditions on osteoarthritis (OA) and rheumatoid arthritis (RA) are sparse and not conclusive. This study aimed to investigate the relationship between temperature change and OA/RA admission. METHODS: Daily OA/RA admission, meteorological data and pollutants from 1 January 2014 to 31 December 2017 in Hefei, China, were collected. We quantified the relationship between ambient temperature and OA/RA admission using a distributed lag nonlinear model (DLNM). Stratified analyses by gender and age were also examined. RESULTS: Temperature decrease was significantly associated with RA admission (25th percentile of temperature versus 50th percentile of temperature), with the acute and largest effect at current days lag (RR: 1.057, 95%CI: 1.005-1.111). However, no significant association between temperature and OA admission was observed. When conducting subgroup analyses by individual characteristics, we found that females and patients aged 41-65 years were more vulnerable to temperature decrease than males, patients aged 0-40 and ≧66 years, respectively. CONCLUSIONS: This study suggested that temperature decrease was a risk factor for increases in RA admission. Females and patients aged 41-65 years were particularly vulnerable to the effect of temperature decrease.

Associations between Work Experience and Betel Nut, Alcohol, or Tobacco Use among Low-Income Taiwanese Students from Middle School to University.

Background: Research suggests that young working students are at higher risk for substance use. However, most studies have focused on students from middle-class families, with few investigations conducted on substance use by students from low-income families. Objective: To examine the associations between work experience and betel nut, alcohol, or tobacco (BAT) use among Taiwanese students from low-income families. Methods: The data for this cross-sectional study were derived from the fourth wave of the Taiwan Panel Study of Children and Youth survey which provides primary data on low-income families. A total of 3,350 low-income students aged 12-25 years old from middle school to university participated. The χ2 test was performed to examine differences in sociodemographic characteristics and BAT use between employed and unemployed students. Multivariate logistic regression was used to examine the associations between work status, work intensity, monthly income, occupation, and BAT use. Results: Employed students displayed higher BAT use than those who were unemployed. Increased BAT use was also associated with higher work intensity (except for betel nut use), higher monthly income, and specific occupations (such as service or manual work). Conclusions: Employment is independently associated with a higher risk of BAT use among low-income Taiwanese students. Work intensity and specific occupational fields may offer insights into formulating relevant preventive measures for these students.