Modifying the Oxidative Potentials of Imines in a Dye Loaded Capsule for Photocatalytic Cyclization with Hydrogen Evolution.

Modifying redox potential of substrates and intermediates to balance pairs of redox steps are important stages for multistep photosynthesis but faced marked challenges. Through co-clathration of iridium photosensitizer and imine substrate within one packet of a metal-organic capsule to shift the redox potentials of substrate, herein, we reported a multiphoton enzymatic strategy for the generation of heterocycles by intramolecular C-X hydrogen evolution cross-couplings. The cage facilitated a pre-equilibrium substrate-involving clathrate that cathodic shifts the oxidation potential of the substrate-dye-host ternary complex and configuration inversion of substrate via spatial constraints in the confined space. The new two photon excitation strategy enabled the precise control of the multistep electron transfer between each pair (photosensitizer, substrate and the capsule), endowing the catalytic system proceeding smoothly with an enzymatic fashion. Three kinds of 2-subsituted (-OH, -NH2 , and -SH) imines and N-aryl enamines all give the corresponding cyclization products efficiently under visible light irradiation, demonstrating the promising of the microenvironment driven thermodynamic activation in the host-dye-substrate ternary for synergistic combination of multistep photocatalytic transformations.

Modifying Enzymatic Substrate Binding within a Metal-Organic Capsule for Supramolecular Catalysis.

Supramolecular catalysis is established to modify reaction kinetics by substrate encapsulation, but manipulating the thermodynamics of electron-transfer reactions remains unexplored. Herein, we reported a new microenvironment-shielding approach to induce an anodic shift in the redox potentials of hydrazine substrates, reminiscent of the enzymatic activation for N-N bond cleavage within a metal-organic capsule H1. Equipped with the catalytic active cobalt sites and substrate-binding amide groups, H1 encapsulated the hydrazines to form the substrate-involving clathration intermediate, triggering the catalytic reduction N-N bond cleavage when electrons were acquired from the electron donors. Compared with the reduction of free hydrazines, the conceptual molecular confined microenvironment decreases the Gibbs free energy (up to -70 kJ mol-1), which is relevant to the initial electron-transfer reaction. Kinetic experiments demonstrate a Michaelis-Menten mechanism, which involves the formation of the pre-equilibrium of substrate-binding, followed by bond cleavage. Then, the distal N is released as NH3 and the product is squeezed. Integrating fluorescein into H1 enabled the photoreduction of N2H4 with an initial rate of ca. 1530 nmol min-1 into ammonia, comparable to that of natural MoFe proteins; thus, the approach provides an attractive manifold toward mimicking enzymatic activation.

Analysis on the Change of College Students' Life Pattern and its Impact during the COVID-19 Outbreak in China.

Objectives: Our objective was to analyze changes in lifestyle patterns of Chinese college students at home during the COVID-19 outbreak. Methods: According to a structured online questionnaire covering socio- demographic information, anthropometric data, and changes in food intake, physical activity, and sleep during the COVID-19 outbreak, the relationships between the above data before and during the outbreak were analyzed. Results: Among the 781 participants, 38.5% had significantly increased their total food intake and 29.1% had significantly decreased their physical activity. Overall, 44% of participants reported weight gain. The average weight gain was 0.7±2.5 kg. The main causes of weight gain were increased food intake (p < .001), decreased physical activity (p < .01), and an excessive increase or reduction in sleep duration (p < .024). Conclusion: During the COVID-19 outbreak, college students' food intake was found to be increased and physical activity decreased; sleep duration was irregular, and all these factors influenced weight gain.

Dye-loaded metal-organic helical capsules applied to the combination of photocatalytic H2S splitting and nitroaromatic hydrogenation.

Two dye-loaded metal-organic capsules constructed with different spatial sizes and functional groups simulated the enzymatic substrate activation for hydrogenation of nitroarenes with the kinetics obeying the Michaelis-Menten mechanism.

"Stay-at-Home" Lifestyle Effect on Weight Gain during the COVID-19 Outbreak Confinement in China.

In February 2020, a novel coronavirus (SARS-COV2) broke out in Wuhan city of China. The Chinese government decisively imposed nationwide confinement. This study comprised a structured, online questionnaire, based on 40 items inquiring about socio-demographic information and anthropometric data (reporting weight and height), as well as changes in food intake, physical activity, and sleep during the COVID-19 outbreak. Questionnaires were distributed to residents of Jiangsu and other provinces from 29 March to 5 April. A total of 889 respondents were included, aged between 16 and 70 years (61% females). There was a significant increase in total food intake by 9.8% and a slight increase by 29.2% of respondents, and a significant decrease in physical activity by 31.5% and a slight decrease by 23.4% of respondents, especially in snacks and drinks, and outdoor activities. The rate of weight gain in the total population was 30.6% and the average weight gain was 0.5 ± 2.8 kg. The main factors contributing to weight gain were increased food intake and reduced physical activity. Additionally, normal-weight people were more likely to gain weight than people with overweight/obesity during the COVID-19 confinement. This study provided a good warning and educational reference value on lifestyle changes during the COVID-19 confinement.