Effects of physical activity on Chinese overseas students' mental health during the COVID-19: A multi-country cross-sectional analysis.

BACKGROUND: COVID-19 caused severe effects on the psychological well-being of Chinese students overseas (COS). Physical activity (PA) is critical to strengthen immunity, prevent infection, and reduce the psychological burden caused by COVID-19. However, there is a severe lack of effective PA intervention for mental health in most countries, and COS have limited access to mental healthcare during the pandemic. OBJECTIVE: We aim to examine the effects of PA on COS' mental health during the pandemic abroad and to better understand that certain types of PA might be associated with a greater reduction in psychological burdens during the pandemic. METHODS AND RESULTS: In a multi-country cross-sectional analysis, a questionnaire was distributed to COS living in 37 foreign countries via WeChat Subscription using a snowball sampling strategy. A total of 10,846 participants were included. Descriptive statistics and Binary logistic regression analysis were used for statistical analysis. We found that COS had negative psychology during the pandemic, especially with fear (2.90, 95% CI 2.88-2.92), anxiety (2.84, 95% CI 2.82-2.85), and stress (2.71, 95% CI 2.69-2.73). PA had meaningful effects on reducing COS self-reported mental health burdens (3.42, 95% CI 3.41-3.44) during the pandemic. The largest associations were seen for recreational and home-based PA (i.e., family games, home aerobic exercise), individual outdoor PA (i.e., walking or running, rope skipping), and PA with a duration of 30 to 70 min per session at frequencies of 4 to 6 times and a total of 150 to 330 min of moderate and vigorous intensity per week tends to be an optimal choice during social distancing times. CONCLUSIONS: COS had several poor mental health conditions during the pandemic. The improvement of PA on COS' psychology was positively effective during the pandemic. Specific types, intensities, durations, and frequencies of PA might have advantages over others for improving COS' mental health during periods of public health emergencies, and the topic may merit interventional study to reveal multiple factors causing COS' psychological burdens and enrich the PA forms for all COS' mental health improvement (i.e., infected, recovered, and asymptomatic COS).

Cardiopulmonary endurance and fitness training strategies for obese adolescents / Estratégias de treinamento de resistência cardiopulmonar e aptidão física para adolescentes obesos / Estrategias de entrenamiento de resistencia cardiopulmonar y aptitud física para adolescentes obesos

ABSTRACT Introduction: Reducing the risk of obesity and maintaining healthy lifestyle habits and physical exercise is very important for adolescents in a crucial period of their development. Objective: Study the effect of physical training on cardiopulmonary resistance and physical fitness in obese adolescents. Methods: Fourteen overweight or obese adolescent students were selected from a school. The experiment lasted four weeks, and the experimental group received a systematic and professional physical training intervention, with two aerobic and two endurance training sessions each week. The control group did not perform any physical exercises except free activities in physical education classes. Results: After four weeks of training, the BMI index of the experimental group changed from 32.84 to 27.68, systolic blood pressure also changed from 118.14mmHg to 93.93mmHg, and diastolic blood pressure was from 69.83mmHg to 55.34mmHg. Conclusion: Elevating professional physical training in adolescents' physical education has shown to be an important attitude to reduce and prevent obesity and its comorbidities. Level of evidence II; Therapeutic studies - investigation of treatment outcomes.

RESUMO Introdução: A redução do risco de obesidade e a manutenção de hábitos de vida saudáveis além do exercício físico são muito importantes para os adolescentes que estão em um período crucial de seu desenvolvimento. Objetivo: Estudar o efeito do treinamento físico sobre a resistência cardiopulmonar e a aptidão física em adolescentes obesos. Métodos: Catorze estudantes adolescentes obesos ou com excesso de peso foram selecionados em uma escola. A experiência teve duração de quatro semanas onde o grupo experimental recebeu uma intervenção sistemática e profissional de treinamento físico, com um total de dois treinamentos aeróbicos e dois de endurance a cada semana. O grupo de controle não realizou exercícios físicos, exceto as atividades livres nas aulas de educação física. Resultados: Após 4 semanas de treinamento, o índice de IMC do grupo experimental mudou de 32,84 para 27,68, a pressão arterial sistólica também sofreu alterações de 118,14mmHg para 93,93mmHg, e a pressão arterial diastólica foi de 69,83mmHg para 55,34mmHg. Conclusão: Elevar o treinamento físico profissional na educação física dos adolescentes mostra-se uma atitude importante para reduzir e prevenir a obesidade e suas comorbidades. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: La reducción del riesgo de obesidad y el mantenimiento de hábitos de vida saludables además del ejercicio físico son muy importantes para los adolescentes que se encuentran en un periodo crucial de su desarrollo. Objetivo: Estudiar el efecto del entrenamiento físico sobre la resistencia cardiopulmonar y la forma física en adolescentes obesos. Métodos: Se seleccionaron catorce estudiantes adolescentes con sobrepeso u obesidad en un centro escolar. El experimento duró cuatro semanas en las que el grupo experimental recibió una intervención sistemática y profesional de entrenamiento físico, con un total de dos sesiones de entrenamiento aeróbico y dos de resistencia cada semana. El grupo de control no realizó ejercicios físicos, salvo actividades libres en las clases de educación física. Resultados: Después de 4 semanas de entrenamiento, el índice de IMC del grupo experimental cambió de 32,84 a 27,68, la presión arterial sistólica también cambió de 118,14mmHg a 93,93mmHg, y la presión arterial diastólica fue de 69,83mmHg a 55,34mmHg. Conclusión: Aumentar la preparación física profesional en la educación física de los adolescentes demuestra ser una actitud importante para reducir y prevenir la obesidad y sus comorbilidades. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

Stereoselective gridization and polygridization with centrosymmetric molecular packing.

The gridarenes, with well-defined edges and vertices, represent versatile nanoscale building blocks for the installation of frameworks and architectures but suffer from difficulty in stereoselective control during their synthesis. Here we report a diastereoselective gridization of superelectrophilic diazafluorene-containing substrates (AmBn) with crescent shapes into Drawing Hands grids (DHGs). The meso-selectivity reaches 75.6% diastereomeric excess (de) during the gridization of A1B1-type substrates and maintains ~80% de during the polygridization of A2B2-type monomers. Such stereocontrol originates from the centrosymmetric molecular packing of two charge-delocalized superelectrophiles with synergistically π-π stacking attractions and coulombic repulsions. As meso-stereoregular structures show 20∼30 nm in length, the rigid ring/chain-alternating polygrids have a Mark-Houwink exponent of 1.651 and a molecular weight (M) dependence of the hydrodynamic radius Rh ∼ M1.13. Via the simulation of chain collapse, meso-configured polygridarenes still adopt rod-like conformations that facilitate the high rigidity of organic nanopolymers, distinguished from toroid backbones of rac-type polygrids.

Superelectrophilic-Initiated C-H Functionalization at the ß-Position of Thiophenes: A One-Pot Synthesis of trans-Stereospecific Saddle-Shaped Cyclic Compounds.

Superelectrophilic-initiated direct C-H functionalization of thiophenes at the ß-position was developed. A series of trans-stereospecific [2,1-a]-IF-thiophene-fused cyclic compounds (4) with saddle-shaped structure were prepared in 17-30% yields through a one-pot superelectrophilic Friedel-Crafts reaction of dihydroindenofluorene with thiophene derivatives. From the crystal packing analyses of 4a, its skeleton shows both strong intermolecular π-π stacking and C-H···π stacking. Furthermore, the ring-dependent photophysical properties of 4 were confirmed by UV-vis absorption and photoluminescence spectroscopy as well as through the study of their fluorescence quantum yield.

[Rapid determination of thiabendazole and carbendazim in concentrated fruit juices by ultra-high performance liquid chromatography-tandem mass spectrometry].

A method was developed for the rapid determination of thiabendazole and carbendazim residues in concentrated fruit juices by using ultra-high performance liquid chromatography (UHPLC) coupled with triple quadrupole tandem mass spectrometry (MS/MS), and quantified by matrix-matched standard solution in external standard method. The residues in the samples were extracted by ethyl acetate, and then analyzed by using UHPLC-MS/MS in multiple reaction monitoring (MRM) mode via positive electrospray ionization with an Waters ACQUITY UPLC BEH C18 column (50 mm x 2.1 mm, 1.7 µm) as the analytical column. Good linearities were obtained in the range of 0.5-10 µg/kg for both pesticides with correlation coefficients greater than 0. 99. The recovery experiments were carried out by spiking standards into blank samples of apple, peach, orange, pear, grape juices at three levels of 0.5, 1.0 and 5.0 µg/kg. The recoveries of thiabendazole and carbendazim were from 76.98% to 108.7% with the relative standard deviations (RSD) of 2.95%-9.99%. For both pesticides in different matrices, the limits of detection (S/N = 3) were in the range of 0.12-0.23 µg/kg. Meanwhile, the pyrolysis mechanism and matrix effects for the determination of thiabendazole and carbendazim in concentrated fruit juices were investigated in this study. The method is simple, rapid and accurate, and can be used for the routine analysis of thiabendazole and carbendazim in concentrated fruit juices.

Photocatalytic oxidation of CO on TiO(2): chemisorption of O(2), CO, and H(2).

On the surface: Adsorption of O(2) at the surface oxygen vacancy (SOV) sites of TiO(2) reconstructs the lattice oxygen (healing SOVs), resulting in a decrease of the photocatalytic activity of oxidizing CO over vacuum-pretreated TiO(2) with increasing temperature (see scheme). Adsorption of H(2) produces new SOVs at the TiO(2) surface and stabilizes the photocatalytic activity. Photocatalytic oxidation of CO over vacuum-pretreated TiO(2) is performed in a series of systems with the introduction of O(2), CO, and H(2) in different orders. The photocatalytic oxidation of CO is dependent on the order of introduction of O(2), CO, or H(2), and introducing O(2) prior to CO promotes the oxidation of CO. Moreover, an increase of reaction temperature suppresses the oxidation of CO, but the preintroduction of H(2) reduces this suppression effect. The results of the chemisorption of O(2), CO, and H(2) at the TiO(2) surface reveal that the adsorbed O(2) heals the surface oxygen vacancy (SOV) sites of TiO(2), while the adsorbed CO and H(2) promote the formation of new SOVs. It is proposed that changes in the amounts of adsorbed O(2) and SOVs are mainly responsible for the differences of CO conversion in different systems.