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1.
Sci Bull (Beijing) ; 69(8): 1081-1090, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38395652

RESUMO

Maximally exploiting the active sites of iridium catalysts is essential for building low-cost proton exchange membrane (PEM) electrolyzers for green H2 production. Herein, we report a novel microdrop-confined fusion/blasting (MCFB) strategy for fabricating porous hollow IrO1-x microspheres (IrO1-x-PHM) by introducing explosive gas mediators from a NaNO3/glucose mixture. Moreover, the developed MCFB strategy is demonstrated to be general for synthesizing a series of Ir-based composites, including Ir-Cu, Ir-Ru, Ir-Pt, Ir-Rh, Ir-Pd, and Ir-Cu-Pd and other noble metals such as Rh, Ru, and Pt. The hollow structures can be regulated using different organics with NaNO3. The assembled PEM electrolyzer with IrO1-x-PHM as the anode catalyst (0.5 mg/cm2) displays an impressive polarization voltage of 1.593 and 1.726 V at current densities of 1 and 2A/cm2, respectively, outperforming commercial IrOx catalysts and most of the ever-reported iridium catalysts with such low catalyst loading. More importantly, the breakdown of the polarization loss indicates that the improved performance is due to the facilitated mass transport induced by the hollowness. This study offers a versatile platform for fabricating efficient Ir-based catalysts for PEM electrolyzers and beyond.

2.
Transl Psychiatry ; 14(1): 102, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38378687

RESUMO

Common mental disorders among young people are rising globally. Current university-based interventions are inadequate to address the need for evidence-based interventions. We investigated the effectiveness and implementation of Step-by-Step (SbS), a WHO digital intervention to address depression, among Chinese university students with depressive symptoms. In this paper, we report a type 1 hybrid effectiveness-implementation randomized controlled trial conducted between September 2021 and September 2022. The control condition was enhanced treatment as usual (ETAU, psychoeducation). The primary outcome was improvement in depression symptoms. Secondary outcomes were improvements in psychological well-being, anxiety symptoms, and self-identified psychosocial problems. Effectiveness of the intervention was evaluated using generalized linear mixed models. Implementation outcomes were evaluated by thematic analysis of participant interviews. A total of 371 participants were enrolled to two treatment conditions in a 1:1 ratio. SbS resulted in a greater reduction in depressive symptoms at posttreatment (p = 0.004, Hedges' g = 0.35), but no significant difference between SbS and ETAU was observed at three-month follow-up (p = 0.179, Hedges' g = 0.16). The treatment effect was larger among those who adhered to the treatment (Hedges' gs = 0.59 and 0.30). Subjective well-being also improved for SbS at both time points (Hedges' gs = 0.31 and 0.30). In addition, SbS resulted in more improvement in anxiety symptoms at posttreatment (p = 0.029, Hedges' g = 0.26), but not at three-month follow-up (p = 0.265, Hedges' g = 0.13). The qualitative results demonstrated that the intervention was well-implemented as a self-help mental health service, with minimal support from peer supporters. In conclusion, Step-by-Step, a digital intervention developed by WHO, was effective in reducing depressive symptoms in the short term and improving psychological well-being in a longer term. The sustained effect on depression needs further investigation. Improving uptake and engagement in the program is needed for its scale-up implementation as a university-based mental health service for Chinese young adults. Trial registration: ChiCTR2100050214.


Assuntos
Depressão , Transtornos Mentais , Humanos , Adulto Jovem , Ansiedade/terapia , Depressão/terapia , Depressão/diagnóstico , Organização Mundial da Saúde
3.
Nanomaterials (Basel) ; 13(16)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37630951

RESUMO

Increasing the loading density of nanoparticles on carbon support is essential for making Pt-alloy/C catalysts practical in H2-air fuel cells. The challenge lies in increasing the loading while suppressing the sintering of Pt-alloy nanoparticles. This work presents a 40% Pt-weighted sub-4 nm PtCo/C alloy catalyst via a simple incipient wetness impregnation method. By carefully optimizing the synthetic conditions such as Pt/Co ratios, calcination temperature, and time, the size of supported PtCo alloy nanoparticles is successfully controlled below 4 nm, and a high electrochemical surface area of 93.8 m2/g is achieved, which is 3.4 times that of commercial PtCo/C-TKK catalysts. Demonstrated by electrochemical oxygen reduction reactions, PtCo/C alloy catalysts present an enhanced mass activity of 0.465 A/mg at 0.9 V vs. RHE, which is 2.0 times that of the PtCo/C-TKK catalyst. Therefore, the developed PtCo/C alloy catalyst has the potential to be a highly practical catalyst for H2-air fuel cells.

4.
Small ; 19(41): e2303172, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37312395

RESUMO

Formic acid is receiving intensive attention as being one of the most progressive chemical fuels for the electrochemical reduction of carbon dioxide. However, the majority of catalysts suffer from low current density and Faraday efficiency. To this end, an efficient catalyst of In/Bi-750 with InOx nanodots load is prepared on a two-dimensional nanoflake Bi2 O2 CO3 substrate, which increases the adsorption of * CO2 due to the synergistic interaction between the bimetals and the exposure of sufficient active sites. In the H-type electrolytic cell, the formate Faraday efficiency (FE) reaches 97.17% at -1.0 V (vs reversible hydrogen electrode (RHE)) with no significant decay over 48 h. A formate Faraday efficiency of 90.83% is also obtained in the flow cell at a higher current density of 200 mA cm-2 . Both in-situ Fourier transform infrared spectroscopy (FT-IR) and theoretical calculations show that the BiIn bimetallic site can deliver superior binding energy to the * OCHO intermediate, thereby fundamentally accelerating the conversion of CO2 to HCOOH. Furthermore, assembled Zn-CO2 cell exhibits a maximum power of 6.97 mW cm-1 and a stability of 60 h.

5.
Inorg Chem ; 62(17): 6856-6863, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-37078576

RESUMO

The hydrogen evolution reaction (HER) involves two-step elementary reactions, providing an opportunity to establish dual-site synergistic catalysts. This work demonstrates carbon-supported Pt single atoms and clusters (Pt1+Cs-NPC) as an efficient catalyst for acidic HER, which exhibits an ultralow Tafel slope of 12.5 mV/dec and an overpotential of 24 mV at 10 mA/cm2 with an ultralow platinum content of 3.8 wt %. The Pt mass activity and turnover frequency (TOF) are 10.2 times and 5.4 times that of commercial Pt/C, respectively. The density functional theory (DFT) study shows that the Pt cluster regulates the electronic state structure of the adjacent Pt single atom, so that the ΔGH* at the Pt1 site approaches 0. Moreover, the DFT study confirms that Pt clusters and neighboring Pt single atoms can synergistically catalyze the Tafel step and reduce the energy barrier in forming the H-H bond. At the same time, the platinum cluster reduces the energy barrier of the nearby platinum single-atom site to the Heyrovsky step and accelerates the reaction with hydrated hydrogen ions. Studies have shown that platinum clusters and platinum single-atom composite loading structures exhibit excellent activity for the Volmer-Tafel or Volmer-Heyrovsky reaction paths of HER reactions. This work provides a clear understanding of the synergistic effect of Pt1+Cs-NPC, which provides guidance for developing efficient HER catalysts.

6.
Int J Biol Macromol ; 224: 1412-1422, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36550790

RESUMO

Superelastic silk fibroin (SF)-based aerogels can be used as multifunctional substrates, exhibiting a promising prospect in air filtration, thermal insulation, and biomedical materials. However, fabrication of the superelastic pure SF aerogels without adding synthetic polymers remains challenging. Here, the SF micro-nano fibrils (SMNFs) that preserved mesostructures are extracted from SF fibers as building blocks of aerogels by a controllable deep eutectic solvent liquid exfoliation technique. SMNFs can assemble into multiscale fibril networks during the freeze-inducing process, resulting in all-natural SMNF aerogels (SMNFAs) with hierarchical cellular architectures after lyophilization. Benefiting from these structural features, the SMNFAs demonstrate desirable properties including ultra-low density (as low as 4.71 mg/cm3) and superelasticity (over 85 % stress retention after 100 compression cycles at 60 % strain). Furthermore, the potential applications of superelastic SMNFAs in air purification and thermal insulation are investigated to exhibit their functionality, mechanical elasticity, and structural stability. This work provides a reliable approach for the fabrication of highly elastic SF aerogels and endows application prospects in air purification and thermal insulation opportunities.


Assuntos
Fibroínas , Seda , Fibroínas/química , Solventes Eutéticos Profundos , Géis/química , Materiais Biocompatíveis
7.
Chem Commun (Camb) ; 59(3): 298-301, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36507902

RESUMO

In this work, we introduce Fe and Ni into Co-MOF to construct a kind of multicomponent phosphide hollow architecture with walls assembled by nanosheets. The multicomponent nature can enhance the intrinsic catalytic activity, while the sheet-like surface and inter-sheet voids provide a large active area, which is beneficial for electrolyte penetration and gas generation. As expected, the optimized product has catalytic hydrogen evolution reaction (HER) overpotentials of 105 and 161 mV at current densities of 10 and 100 mA cm-2, respectively, and maintained long-term stability for over 100 hours at 10 mA cm-2 current densities.

8.
Inorg Chem ; 62(2): 782-791, 2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36583676

RESUMO

Low-temperature catalytic CO oxidation is an important chemical process in versatile applications, such as the H2 utilization for low-temperature H2 air fuel cells. Pt-group metal catalysts are efficient but highly cost-consuming. This work demonstrates an excellent and sixpenny catalyst with earth-abundant Ni and Ce, in which Ni ions are atomically incorporated into the CeO2 matrix (Ni-Ce-Ox) by synchronous spray-pyrolysis (SSP) of mixture nitrates of Ni and Ce. The Ni-Ce-Ox catalyst presents a mesoporous structure. Revealed by a model reaction of 1% CO, 1% O2, and 98% balance He at a space velocity of 13,200 mL/gcat/h, Ni-Ce-Ox catalysts display a typical volcano-shaped relationship between reactivity and Ni incorporation amount. The optimized Ni incorporation appears with a high Ni/Ce atomic ratio of 0.25, endowing the T50 (temperature corresponding to a CO conversion of 50%), which is lower-shifted by 165 °C than that of pristine CeO2 (266 °C). The density functional theory (DFT) calculations further indicate that the much-reduced oxygen vacancy formation energy at Ni-Ce single-atom sites boosted the adsorption activation of the CO molecule and therefore promoted the CO oxidation process. Besides, the2 Ni-Ce-Ox from the SSP method presents better performance than the counterparts from immersion and hydrothermal methods. This work paves a way to access efficient noble-metal-free catalysts for low-temperature CO oxidation.

9.
Sch Psychol Int ; 44(4): 489-512, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38603326

RESUMO

There is evidence showing that the triarchic model of grit and its dimensions (i.e., perseverance of effort, consistency of interests, and adaptability to situations) predict engagement and well-being outcomes in high school and undergraduate students during the COVID-19 pandemic outbreak. However, there has been limited research on how this model of grit relates to engagement and optimal psychological outcomes in primary school students. This research investigates the association of grit's dimensions with academic engagement in math and science as well as well-being outcomes (i.e., positive emotions, negative emotions, and flourishing) in primary school students. Participants were primary school students (Mage = 10.42; SDage = 1.26) from Hong Kong (n = 279) and Macau (n = 124). Results showed that perseverance of effort positively predicted cognitive and behavioral engagement in math as well as positive emotions even after controlling for demographic covariates (i.e., age, gender, setting, and year level), conscientiousness, and achievement goal orientations. Adaptability to situations positively predicted cognitive and social engagement in math and flourishing. Consistency of interests negatively predicted both cognitive engagement in science and negative emotions. Indeed, this study indicates that perseverance and adaptability may facilitate children's positive academic and psychological functioning during the COVID-19 pandemic outbreak.

10.
Internet Interv ; 30: 100579, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36217366

RESUMO

Background: Among Chinese college students, the burden of depression is considerably high, affecting up to 30 % of the population. Despite this burden, few Chinese students seek mental health treatment. In addition, depression is highly comorbid with other mental health disorders, such as anxiety. Scalable, transdiagnostic, evidence-based interventions are needed for this population. Objective: The study will evaluate the effectiveness of a World Health Organization transdiagnostic digital mental health intervention, Step-by-Step, to reduce depressive and anxiety symptoms and improve well-being compared with enhanced care as usual and its implementation in a Chinese university community. Methods: A type 1 effectiveness-implementation two-arm, parallel, randomized controlled trial will be conducted. The two conditions are 1) the 5-session Step-by-Step program with minimal guidance by trained peer-helpers and 2) psychoeducational information on depression and anxiety and referrals to local community services. A total of 334 Chinese university students will be randomized with a 1:1 ratio to either of the two groups. Depression, anxiety, wellbeing, and client defined problems will be assessed at pre-intervention, post-intervention, and 3-month follow-up. Endline qualitative interviews and focus group discussions will be conducted to explore SbS implementation among service users, university staff, and stakeholders. Data will be analysed based on the intent-to-treat principle. Discussion: Step-by-Step is an innovative approach to address common mental health problems in populations with sufficient digital literacy. It is a promising intervention that can be embedded to scale mental health services within a university setting. It is anticipated that after successful evaluation of the program and its implementation in the type 1 hybrid design RCT study, Step-by-Step can be scaled and maintained as a low-intensity treatment in universities, and potentially extended to other populations within the Chinese community. Trial registration: ChiCTR2100050214.

11.
Angew Chem Int Ed Engl ; 61(45): e202212338, 2022 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-36102497

RESUMO

The two-dimensional nanosheets are conducive to not only endow opened surfaces for loading active metal atoms but also boost the mass transfer for the heterogeneous reactions. The challenge is how to load and stabilize single-atoms on nanosheets in high-areal densities. This work reports an efficient micro-gas blasting (MGB) strategy to access versatile noble metal single-atoms/metal oxide nanosheets, including Ir1 /CoOx , Pd1 /CeO2 , etc. Especially for Pt/CeO2 nanosheets (Pt1 /CeO2 -S), the Pt loading is increased to 15 at%. The Pt1 /CeO2 -S catalysts from MGB are revealed to possess superior reactivity and tolerance in the model reaction of water-gas shift (WGS). The Pt1 /CeO2 -S catalyst exhibit 2-3 times reactivity that of their thicker counterpart, single-atom Pt1 /CeO2 microspheric catalyst. Moreover, the single-atom sites in Pt1 /CeO2 -S (1-10 %) catalysts are stable in a harsh WGS reaction condition of 10 % CO. This work thus paves a way to access the practical single-atom catalysts.

12.
Inorg Chem ; 61(30): 11932-11938, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35848216

RESUMO

The properties of supports have a significant effect on the activity of noble metal single atoms. In this work, Co-doped CeO2-supported single-atom Pt catalysts (Pt1/Co-CeO2) have been acquired by a synchronous pyrolysis/deposition route and demonstrated to promote low-temperature oxidation of CO. Revealed by a model reaction of 1% CO + 1% O2 + 98% He at a space velocity of 12,000 mL/gcat/h, CO conversion (100 °C) acquired on a (0.5% Pt)/(10% Co-CeO2) catalyst (36.6%) was 3.6 and 4.9 times those of 0.5% Pt/CeO2 (10.0%) and 10% Co-CeO2 (7.4%) catalysts and 2.1 times that of their conversion sum (17.4%), confirming the positive role of the Co dopant in boosting the low-temperature oxidation of CO. The consistent results are also verified in the comparison of Pt1/Co-ZnO with Pt1/ZnO and Pt1/Co-Al2O3 with Pt1/Al2O3. In addition, the activity of single-atom Pt1/Co-CeO2 catalysts can be facilely modified by changing the loading of Pt and/or doping amount of Co. These reasonable data will provide a methodology to access more applicable catalysts for CO oxidation at low temperature.

13.
ACS Appl Mater Interfaces ; 13(4): 5079-5087, 2021 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-33470784

RESUMO

Ruthenium nanocrystals with small size and special morphology are of great interest in various catalytic reactions due to their high activities. However, it is still a great challenge to downsize these nanocatalysts to a sub-nano scale (<2 nm). Herein, we reported a synthesis of ultrasmall size and uniform Ru nanoparticles through a rapid one-pot method. The prepared Ru nanocrystal shows a wormlike shape, in which the diameter is as thin as 1.6 ± 0.3 nm and the length is 13.6 ± 4.4 nm. These Ru nanoworms (NWs) are quite steady during the synthetic process even though the reaction time was further prolonged. We also examined their catalytic activity toward CO oxidation by loading Ru NWs on TiO2 to form Ru NWs/TiO2 catalysts. These catalysts exhibit a high activity of 100% CO conversion at 150 °C, which is much lower than the normal Ru NPs/TiO2 nanostructures. Based on our detailed investigations, we proposed that the small size, special morphology, and TiO2 support are the keys for their significantly improved catalytic activity. We believed that these reasonable discoveries provide a methodology and opportunity to get highly active catalysts for CO oxidation by a detailed increase in their active sites.

14.
Front Psychiatry ; 12: 812667, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35069297

RESUMO

Background: Chinese young adults experience barriers to mental health treatment, including the lack of treatment providers and stigma around treatment seeking. Evidence-based digital mental health interventions are promising and scalable alternatives to face-to-face treatment for this population, but lack rigorous evidence to support scale-up in China. Aim: The study was a feasibility study for a large-scale RCT of Step-by-Step, a behavioral activation-based, mental health intervention to address depression and anxiety symptoms in Chinese young adults. It sought to assess feasibility of recruitment and of delivery of Step-by-Step in a University setting, to assess acceptability of the intervention, and to examine potential effectiveness. Method: An uncontrolled, feasibility trial was conducted to assess the feasibility and acceptability of Chinese Step-by-Step for Chinese University students with elevated depressive symptoms (PHQ-9 scores at or above 10) in Macao, China. Data was collected at two different time points (i.e., baseline and 8-weeks after baseline), administered via questionnaires embedded in an interventional mobile application. Participation rate and dropout rate were measured. Depressive and anxiety symptom severity, well-being, and self-defined stress were assessed. Satisfaction with the program was assessed using qualitative interviews. Results: A total of 173 students were screened, 22.0% (n = 38) were eligible, and 63.2% of them (n = 24) started the intervention. The dropout rate by post-test was 45.8%. Results from completers showed that Step-by-Step was potentially effective in reducing depressive and anxiety symptom severity, and self-defined stress. Students were generally satisfied with the program, but also offered suggestions for continued improvement. Qualitative feedback was reported within the RE-AIM framework, covering recruitment, effectiveness, adoption, implementation, and maintenance. Amendments to the program were made according to the feedback (e.g., adding notification for new session, modify the time zone). Conclusion: A minimally guided Step-by-Step protocol and the study procedure were successfully pilot tested for use for Chinese University students. The intervention was acceptable and no adverse events were reported. The results support the potential effectiveness and feasibility of a large-scale evaluation of the program.

15.
Artigo em Inglês | MEDLINE | ID: mdl-32422914

RESUMO

Despite the increasing research attention being paid to gaming disorder globally, a screening tool developed specifically for the Chinese population is still lacking. This study aims to address this gap by constructing a screening tool to assess Internet gaming disorder (IGD) symptomology, defined by the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), among Chinese gamers. Based on expert interviews and consultations, a focus group of gamers, a background literature review, and the IGD criteria proposed by the DSM-5, we developed the Chinese Internet Gaming Disorder Checklist (C-IGDC). This study evaluated its dimensional structure, reliability, validity, and screening efficacy with 464 Chinese past-year gamers (53% female; mean age = 19.84). The two-level structure of the 27-item C-IGDC showed a satisfactory model fit, acceptable reliability, as well as good validity via expected associations with Internet addiction, gameplay frequency, and depressive symptoms. The optimal screening cutoff score (≥20) was proposed to detect probable IGD cases. The C-IGDC is the first DSM-5-based, multidimensional IGD screening tool designed specifically for Chinese gamers. Further evaluation of the C-IGDC in epidemiological studies and clinical settings is recommended.


Assuntos
Comportamento Aditivo , Lista de Checagem , Jogos de Vídeo , Adolescente , Comportamento Aditivo/diagnóstico , Feminino , Humanos , Internet , Masculino , Reprodutibilidade dos Testes , Adulto Jovem
16.
Nat Commun ; 11(1): 48, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31911600

RESUMO

Selective reduction of ketone/aldehydes to alcohols is of great importance in green chemistry and chemical engineering. Highly efficient catalysts are still demanded to work under mild conditions, especially at room temperature. Here we present a synergistic function of single-atom palladium (Pd1) and nanoparticles (PdNPs) on TiO2 for highly efficient ketone/aldehydes hydrogenation to alcohols at room temperature. Compared to simple but inferior Pd1/TiO2 and PdNPs/TiO2 catalysts, more than twice activity enhancement is achieved with the Pd1+NPs/TiO2 catalyst that integrates both Pd1 and Pd NPs on mesoporous TiO2 supports, obtained by a simple but large-scaled spray pyrolysis route. The synergistic function of Pd1 and PdNPs is assigned so that the partial Pd1 dispersion contributes enough sites for the activation of C=O group while PdNPs site boosts the dissociation of H2 molecules to H atoms. This work not only contributes a superior catalyst for ketone/aldehydes hydrogenation, but also deepens the knowledge on their hydrogenation mechanism and guides people to engineer the catalytic behaviors as needed.

17.
Chemistry ; 25(68): 15586-15593, 2019 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-31574171

RESUMO

Development of Pt group metal-free catalysts for low-temperature CO oxidation remains critical. In this work, active and stable mesoporous Cu-Ce-Ox solid solutions are prepared by using spray pyrolysis. The specific surface areas and pore volumes reach as high as 170 m2 g-1 and 0.24 cm3 g-1 , respectively. The results of CO oxidation study suggest that (1) the catalyst obtained by spray pyrolysis possesses much higher activity than those made by co-precipitation, sol-gel, and hydrothermal methods; (2) the optimal Cu0.2 -Ce0.8 -Ox solid solution presents a reactivity over 28 times that of both single-component CuO and CeO2 at 70 °C. Based on the study of pure-phase Cu-Ce-Ox solid solutions by selective leaching of segregated CuOx species, the active center for CO oxidation is confirmed as the bimetallic Cu-Ce-O site, whereas the individual CuOx particles not only act as spectators but also block the active Cu-Ce-O sites. A low apparent activation energy of approximately 48 kJ mol-1 is detected for CO oxidation at the Cu-Ce-O site, making Cu-Ce-Ox solid solutions able to present high activity at low temperature. Furthermore, the Cu-Ce-Ox catalysts exhibit excellent stability and thermal tolerance toward CO oxidation.

18.
ChemSusChem ; 12(12): 2564-2569, 2019 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-31017344

RESUMO

Efficient, abundant and low-cost catalysts for the oxygen evolution reaction (OER) are required for energy conversion and storage. In this study, a doping-etching route has been developed to access defect rich Fe-Co-Al (Fe-Co-Al-AE) ternary hydroxide nanosheets for superior electrochemical oxygen evolution. After partial etching of Al, ultrathin Fe3 Co2 Al2 -AE electrocatalysts with a rich pore structure are obtained with a shift of the cobalt valence state towards higher valence (Co2+ →Co3+ ), along with a substantial improvement in the catalytic performance. Fe3 Co2 Al2 -AE shows a notably lower overpotential of only 284 mV at a current density of 10 mA cm-2 and double the OER mass activity of the etching-free Fe3 Co2 Al2 with an overpotential of 350 mV. Density functional theory shows the leaching of Al changes the rate-determining step of the OER from conversion of *OOH into O2 on Fe3 Co2 Al2 to formation of OOH from *O on the Al-defective catalysts. This work demonstrates an effective route to design and synthesize transition metal electrocatalysts and provides a promising alternative for the further development of oxygen evolution catalysts.

19.
Psychiatry Res ; 270: 394-403, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30300870

RESUMO

Mental disorders and sleep dysfunction are common among Chinese university students. This study aimed to evaluate a low cost scalable mindfulness intervention program to improve psychological health and sleep quality among Chinese university students. A randomized controlled trial with 101 university students (mean age 22.30 ±â€¯2.63, 69.31% female) was conducted. Participants were randomized into 4 groups: Group 1: control group (n = 25), Group 2: mindfulness only group (n = 27), Group 3: mindfulness + plain-text reminder group (n = 24), and Group 4: mindfulness + enhanced text reminder with animal meme group (n = 25).The mindfulness intervention consisted of two in-person guided sessions along with weekly self-guided practice for 7 weeks. The Depression, Anxiety and Stress Scale (DASS-21) and The Pittsburgh Sleep Quality Index (PSQI) were used to measure depression, anxiety, stress, and sleep dysfunction. After the intervention at week 4, compared to controls, completers in group 2, 3 and 4 (n = 42) showed significantly reduced depression (Cohen's d = 0.83), anxiety (Cohen's d = 0.84), and stress (Cohen's d = 0.75), and improved subjective sleep quality (Cohen's d = 2.00), sleep latency (Cohen's d = 0.55), and habitual sleep efficiency (Cohen's d = 0.86). The effect was maintained at week 7. Low-intensity mindfulness interventions might be a useful intervention program in university settings.


Assuntos
Povo Asiático/psicologia , Atenção Plena/métodos , Estudantes/psicologia , Telemedicina/métodos , Universidades , Adulto , Ansiedade/epidemiologia , Ansiedade/psicologia , Ansiedade/terapia , Depressão/epidemiologia , Depressão/psicologia , Depressão/terapia , Feminino , Humanos , Masculino , Saúde Mental/normas , Atenção Plena/normas , Método Simples-Cego , Sono/fisiologia , Estresse Psicológico/epidemiologia , Estresse Psicológico/psicologia , Estresse Psicológico/terapia , Telemedicina/normas , Universidades/normas , Adulto Jovem
20.
Angew Chem Int Ed Engl ; 56(47): 14977-14981, 2017 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-29024224

RESUMO

A mesoporous MnCo2 O4 electrode material is made for bifunctional oxygen electrocatalysis. The MnCo2 O4 exhibits both Co3 O4 -like activity for oxygen evolution reaction (OER) and Mn2 O3 -like performance for oxygen reduction reaction (ORR). The potential difference between the ORR and OER of MnCo2 O4 is as low as 0.83 V. By XANES and XPS investigation, the notable activity results from the preferred MnIV - and CoII -rich surface. The electrode material can be obtained on large-scale with the precise chemical control of the components at relatively low temperature. The surface state engineering may open a new avenue to optimize the electrocatalysis performance of electrode materials. The prominent bifunctional activity shows that MnCo2 O4 could be used in metal-air batteries and/or other energy devices.

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