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Fine-tuning nanoscale structures, morphologies, and electronic states are crucial for creating efficient water-splitting electrocatalysts. In this study, a method for electronic structure engineering to enhance overall water splitting in a corrosion-resistant electrocatalyst matrix by integrating Pt, P dual-doped Ni4Mo electrocatalysts onto a Ti4O7 nanorod grown on carbon cloth (Pt, P-Ni4Mo-Ti4O7/CC) is introduced. By optimizing platinum and phosphorus concentrations to 1.18% and 2.42%, respectively, low overpotentials are achieved remarkably: 24 mV at 10 mA cm-2 for the hydrogen evolution reaction and 290 mV at 20 mA cm-2 for the oxygen evolution reaction in 1.0 m KOH. These values approach or surpass those of benchmark Pt-C and IrO2 catalysts. Additionally, the Pt, P-Ni4Mo-Ti4O7/CC bifunctional electrocatalyst displays low cell potentials across various mediums, maintaining excellent current retention (96% stability after 40 h in mimic seawater at 20 mA cm-2) and demonstrating strong corrosion resistance and suitability for seawater electrolysis. As a cathode in magnesium/seawater batteries, it achieves a power density of 7.2 mW cm-2 and maintains stability for 100 h. Density functional theory simulations confirm that P, Pt doping-assisted electronic structure modifications augment electrical conductivity and active sites in the hybrid electrocatalysts.
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Future energy loss can be minimized to a greater extent via developing highly active electrocatalysts for alkaline water electrolyzers. Incorporating an innovative design like high entropy oxides, dealloying, structural reconstruction, in situ activation can potentially reduce the energy barriers between practical and theoretical potentials. Here, a Fd-3m spinel group high entropy oxide is developed via a simple solvothermal and calcination approach. The developed (FeCoMnZnMg)3O4 electrocatalyst shows a near equimolar distribution of all the metal elements resulting in higher entropy (ΔS ≈1.61R) and higher surface area. The self-reconstructed spinel high entropy oxide (S-HEO) catalyst exhibited a lower overpotential of 240 mV to reach 10 mA cm-2 and enhanced reaction kinetics (59 mV dec-1). Noticeably, the S-HEO displayed an outstanding durability of 1000 h without any potential loss, significantly outperforming most of the reported OER electrocatalysts. Further, S-HEO is evaluated as the anode catalyst for an anion exchange membrane water electrolyzer (AEMWE) in 1 m, 0.1 m KOH, and DI water at 20 and 60 °C. These results demonstrate that S-HEO is a highly attractive, non-noble class of materials for high active oxygen evolution reaction (OER) electrocatalysts allowing fine-tuning beyond the limits of bi- or trimetallic oxides.
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Rational design of highly efficient noble-metal-unbound electrodes for hydrogen and oxygen production at increased current density is crucial for robust water-splitting. A facile hydrothermal and room-temperature aging method is presented, followed by chemical vapor deposition (CVD), to create a self-sacrificed hybrid heterostructure electrocatalyst. This hybrid material, (Mn-(Co,Ni)2P/CoP/(N,S)-C), comprises manganese-doped cobalt nickel phosphide (Mn-(Co,Ni)2P) nanofeathers and cobalt phosphide (CoP) nanocubes embedded in a nitrogen and sulfur co-doped carbon matrix (N,S)-C on nickel foam. The catalyst exhibits excellent performance in both the hydrogen evolution reaction (HER; η10 = 61 mV) and oxygen evolution reaction (OER; η10 = 213 mV) due to abundant active sites, high porosity, and enhanced hetero-interface interaction between Mn-(Co2P-Ni2P) CoP, and (N,S)-C supported by significant synergistic effects observed among different phases through density functional theory (DFT) calculations. Impressively, (Mn-(Co,Ni)2P/CoP/(N,S)-C (+,-) shows an extra low cell voltage of 1.49 V@10 mA cm-2. Moreover, the catalyst exhibits remarkable stability at 100 and 300 mA cm-2 when operating as a single stack cell electrolyzer. The superior electrochemical activity is attributed to the enhanced electrode-electrolyte interface among the multiple phases of the hybrid structure.
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BACKGROUND: Medical students perceive the transition to clerkship education as stressful and challenging and view themselves as novices during their rotation in clerkship education. The developmental perspective is thus important because the transition to clerkship supports rather than hinders growth. Accordingly, this study examines medical students' transition to clerkship and their developmental features. METHODS: In-depth interviews were conducted with 18 medical students or graduates who had completed clerkships as medical students. Based on Straussian grounded theory, the collected data were analyzed in terms of the differences between pre- and post-clerkship education. RESULTS: Our data analysis revealed five stages of the transition process: "anticipation and anxiety," "reality check," "seeking solutions," "practical application," and "transition and stability." The core category, that is, "growing up from being students to being student doctors," was driven by patients who perceived the participants as student doctors. Meanwhile, the participants recognized that having a solution that is agreed upon by colleagues was more important than knowing the correct answer. The participants undergoing the transition to clerkship showed developmental features divided into three categories: personal, social, and professional. Specifically, they attempted to balance clerkship and life through personal development, learned to navigate around the hospital and reduced tension through social development, and developed clinical competencies focused on efficiency through professional development. CONCLUSIONS: This study explores the process of students' transition to clerkship education and the developmental features that emerge during this period. The students were motivated by patients who perceived them as student doctors. Through the transition, they maintained a work-life balance and adapted to hospitals but developed an overly doctor-centered attitude by cultivating clinical competencies with a focus on efficiency. To develop them into medical professionals, it is essential to assist their transition and cultivate a patient-centered attitude.
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Estágio Clínico , Teoria Fundamentada , Pesquisa Qualitativa , Estudantes de Medicina , Humanos , Estudantes de Medicina/psicologia , Feminino , Masculino , Adulto , Entrevistas como Assunto , Adulto Jovem , Competência ClínicaRESUMO
BACKGROUND: To improve the medical professionalism of medical students, it is essential to understand the dilemmas they face in various situations. This study explored the types and distribution of dilemmas Korean medical students encounter during their clinical clerkships. It then compared these with previous dilemma frameworks and identified the types and distribution of "complexity dilemmas," wherein two dilemma themes emerge in a single clinical situation. METHODS: The researchers organized and recorded a group discussion with 106 third-year medical students who had completed their clinical clerkships. These students participated in the discussion as part of an assignment, focusing on the dilemmas they encountered during their clerkships. For data analysis and visualization, the researchers employed the MAXQDA software program and utilized the template analysis method, a qualitative research methodology. RESULTS: A total of seven dilemma themes and sixteen sub-themes were identified. The identity-related dilemma concerning student-doctors had the highest frequency. The themes "mismatch" and "Nun-chi" emerged as new additions not found in previous dilemma frameworks. The complexity dilemmas appeared in the sequence of "identity-dignity," "identity-abuse," and "identity-consent". CONCLUSIONS: To navigate the unique dilemmas present within South Korea's clinical culture, several key issues need consideration: elevating the role of student-doctors, balancing the primary emphasis of educational hospitals on delivering medical services, and understanding interpersonal strategies, such as "Nun-chi".
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Estágio Clínico , Estudantes de Medicina , Humanos , Profissionalismo , República da CoreiaRESUMO
Herein, we aimed to formulate a novel oral disintegrating tablet (ODT) of aripiprazole (ARP) capable of rapid disintegration using a direct compression technique. Different ODTs were fabricated with directly compressible excipients, and their disintegration time, wettability (water absorption ratio and wetting time), and mechanical properties (hardness and friability) were evaluated. The optimized ODT comprised F-Melt® type C, Prosolv® SMCC HD90, and Na croscarmellose (10 mg of ARP in a 130 mg tablet). The ODT with 3.1-5.2 kp hardness exhibited rapid disintegration (14.1-17.2 sec), along with appropriate mechanical strength (friability < 0.24%). In a bioequivalent study in Korean healthy subjects (randomized, single-dose, two-period crossover design, n = 37), the novel ODT offered the equivalent pharmacokinetic profile to that of a conventional immediate release tablet (Otsuka, Abilify®, Japan), despite different disintegration and dissolution profiles. The 90% confidence intervals of the geometric mean test to reference ratios considering the area-under-the-curve and maximum plasma drug concentrations were 1.0306-11051 and 0.9448-1.1063, respectively, satisfying FDA regulatory criteria for bioequivalence. The novel ART ODT was physicochemically stable under the accelerated storage condition (40 °C, RH75%) for 24 weeks. Therefore, the novel ARP-loaded ODT is expected to be an alternative to oral ARP therapy, providing improved patient adherence.
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Aripiprazol , Humanos , Administração Oral , Solubilidade , Comprimidos/química , Equivalência Terapêutica , Estudos Cross-OverRESUMO
Tuning the coordination environment and geometric structures of single atom catalysts is an effective approach for regulating the reaction mechanism and maximize the catalytic efficiency of single-atom centers. Here, a template-based synthesis strategy is proposed for the synthesis of high-density NiNx sites anchored on the surface of hierarchically porous nitrogen-doped carbon nanofibers (Ni-HPNCFs) with different coordination environments. First-principles calculations and advanced characterization techniques demonstrate that the single Ni atom is strongly coordinated with both pyrrolic and pyridinic N dopants, and that the predominant sites are stabilized by NiN3 sites. This dual engineering strategy increases the number of active sites and utilization efficiency of each single atom as well as boosts the intrinsic activity of each active site on a single-atom scale. Notably, the Ni-HPNCF catalyst achieves a high CO Faradaic efficiency (FECO ) of 97% at a potential of -0.7 V, a high CO partial current density (jCO ) of 49.6 mA cm-2 (-1.0 V), and a remarkable turnover frequency of 24 900 h-1 (-1.0 V) for CO2 reduction reactions (CO2 RR). Density functional theory calculations show that compared to pyridinic-type NiNx , the pyrrolic-type NiN3 moieties display a superior CO2 RR activity over hydrogen evolution reactions, resulting in their superior catalytic activity and selectivity.
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Zinc-air batteries are gaining popularity as viable energy sources for green energy storage technologies. The cost and performance of Zn-air batteries are mostly determined by the air electrodes in combination with an oxygen electrocatalyst. This research aims at the particular innovations and challenges relating to air electrodes and related materials. Here, a nanocomposite of ZnCo2 Se4 @rGO that exhibits excellent electrocatalytic activity for the oxygen reduction reaction, ORR (E1/2 = 0.802 V), and oxygen evolution reaction, OER (η10 = 298 mV@10 mA cm-2 ) is synthesized. In addition, a rechargeable zinc-air battery with ZnCo2 Se4 @rGO as the cathode showed a high open circuit voltage (OCV) of 1.38 V, a peak power density of 210.4 mW cm-2 , and outstanding long-term cycling stability. The electronic structure and oxygen reduction/evolution reaction mechanism of the catalysts ZnCo2 Se4 and Co3 Se4 are further investigated using density functional theory calculations. Finally, a perspective for designing, preparing, and assembling air electrodes is suggested for the future developments of high-performance Zn-air batteries.
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The development of trifunctional electrocatalyst for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) with deeply understanding the mechanism to enhance the electrochemical performance is still a challenging task. In this work, the distorted metastable hybrid-phase induced 1T'/1T Co,PSnS2 nanosheets on carbon cloth (1T'/1T Co,PSnS2 @CC) is prepared and examined. The density functional theoretical (DFT) calculation suggests that the distorted 1T'/1T Co,PSnS2 can provide excellent conductivity and strong hydrogen adsorption ability. The electronic structure tuning and enhancement mechanism of electrochemical performance are investigated and discussed. The optimal 1T'/1T Co,PSnS2 @CC catalyst exhibits low overpotential of ≈94 and 219.7 mV at 10 mA cm-2 for HER and OER, respectively. Remarkably, the catalyst exhibits exceptional ORR activity with small onset potential value (≈0.94 V) and half-wave potential (≈0.87 V). Most significantly, the 1T'/1T Co,PSnS2 ||Co,PSnS2 electrolyzer required small cell voltages of ≈1.53, 1.70, and 1.82 V at 10, 100, and 400 mA cm-2 , respectively, which are better than those of state-of-the-art Pt-C||RuO2 (≈1.56 and 1.84 V at 10 and 100 mA cm-2 ). The present study suggests a new approach for the preparation of large-scalable, high performance hierarchical 3D next-generation trifunctional electrocatalysts.
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Chimeric antigen receptor (CAR) T-cells anti-CD30 is an innovative therapeutic option that has been used to treat cases of refractory/relapsed (R/R) classic Hodgkin lymphoma (CHL). Limited data are available regarding the CD30 expression status of patients who relapsed after this therapy. This is the first study to show decreased CD30 expression in R/R CHL in patients (n = 5) who underwent CAR T-cell therapy in our institution between 2018 and 2022. Although conventional immunohistochemical assays showed decreased CD30 expression in neoplastic cells in all cases (8/8) the tyramide amplification assay and RNAScope in situ hybridisation detected CD30 expression at different levels in 100% (n = 8/8) and 75% (n = 3/4), respectively. Hence, our findings document that certain levels of CD30 expression are retained by the neoplastic cells. This is not only of biological interest but also diagnostically important, as detection of CD30 is an essential factor in establishing a diagnosis of CHL.
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Doença de Hodgkin , Imunoconjugados , Humanos , Doença de Hodgkin/patologia , Antígeno Ki-1/metabolismo , Imunoterapia Adotiva , Imunoconjugados/uso terapêuticoRESUMO
BACKGROUND: Although research experience is important for medical students, it is difficult to develop research skills only through a formal curriculum. To develop research programs that address the authentic needs of students and align with the entirety of the medical school curriculum, a learner-centered approach may be more effective than an instructor-centered approach. This study investigates medical student perspectives on factors that help them develop research competency. METHODS: Hanyang University College of Medicine in South Korea operates the Medical Scientist Training Program (MSTP) as a supplement to its formal curriculum. Semi-structured interviews were held with 18 students (20 cases) in the program, and qualitative content analysis was performed using the software tool MAXQDA20. RESULTS: The findings are discussed in relation to three domains: learner engagement, instructional design, and program development. The students were more engaged when they perceived the program as a new experience, had prior research experience, wanted to make a good impression, and felt a sense of contribution. In terms of instructional design, they positively participated in research when their supervisors respected them, set clear tasks, provided constructive feedback, and invited them into the research community. In particular, the students highly valued relationships with their professors, and these relationships served not only as a main motivating factor in their research participation but also affected their college lives and careers. CONCLUSIONS: The longitudinal relationship between students and professors has newly emerged in the Korean context as a factor that strengthens student engagement in research and the complementary relationship between formal curriculum and MSTP was highlighted to encourage student engagement in research.
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Educação de Graduação em Medicina , Estudantes de Medicina , Humanos , Currículo , Pesquisa Qualitativa , AtitudeRESUMO
BACKGROUND: The COVID-19 pandemic has highlighted prosocial behavior as a professional healthcare core competency. Although medical students are expected to work in the best interests of their patients, in the pandemic context, there is a greater need for ethical attention to be paid to the way medical students deal with moral dilemmas that may conflict with their obligations. METHODS: This study was conducted in the spring semester of 2019 on 271 students majoring in health professions: medicine, dentistry, and veterinary medicine. All participants provided informed consent and completed measures that assessed utilitarian moral views, cognitive reflections, cognitive reappraisal, and moral judgment. RESULTS: The healthcare-affiliated students who scored higher on the instrumental harm subscale in the measurement of utilitarian moral views were more likely to endorse not only other-sacrificial actions but also self-sacrificial ones for the greater good in moral dilemma scenarios. In particular, those engaged in deliberative processes tended to make more self-sacrificial judgments. The mediation analysis also revealed that the effect of deliberative processes on self-sacrificial judgments was mediated by cognitive reappraisal. CONCLUSIONS: These findings suggested that cognitive reappraisal through deliberative processes is involved when the students with utilitarian inclination make prosocial decisions, that it is necessary to consider both moral views and emotional regulation when admitting candidates, and that moral education programs are needed in the healthcare field.
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COVID-19 , Pandemias , Atenção à Saúde , Humanos , Princípios Morais , EstudantesRESUMO
Atomic metal-modulated heterostructures have been evidenced as an exciting solution to develop high-performance multifunctional electrocatalyst toward water splitting. In this research, a catalyst of continuous cobalt-cobalt oxide (Co-CoO) lateral heterostructures implanted with well-dispersed rhodium (Rh) atoms and shelled over conductive porous 1D copper (Cu) nano-supports for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in both freshwater and seawater under alkaline condition is proposed. It is found that synergistic effects coming from uniform Rh atoms at doping level and Co-CoO heterostructures afford rich multi-integrated active sites and excellent charge transfer, thereby effectively promoting both HER and OER activities. The material requires overpotentials of 107.3 and 137.7 mV for HER and 277.7 and 260 mV for OER to reach an output of 10 mA cm-1 in freshwater and mimic seawater, respectively, surpassing earlier reported catalysts. Compared to a benchmark a Pt/C//RuO2 -based two-electrode electrolyzer, a device derived from the 1D-Cu@Co-CoO/Rh on copper foam delivers comparable cell voltages of 1.62, 1.60, and 1.70 V at 10 mA cm-2 in freshwater, mimic seawater, and natural seawater, respectively, together with robust stability. These results evidence that 1D-Cu@Co-CoO/Rh is a promising catalyst for green hydrogen generation via freshwater and seawater electrolysis applications.
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Enhancer of zeste homolog 2 (EZH2) is a catalytic component of the polycomb repressive complex 2 (PRC2) which reduces gene expression via trimethylation of a lysine residue of histone 3 (H3K27me3). Expression of EZH2 has not been assessed systematically in mantle cell lymphoma (MCL). Expression of EZH2 was assessed by immunohistochemistry in 166 patients with MCL. We also assessed other PRC2 components and H3K27me3. Fifty-seven (38%) of MCL patients were positive for EZH2 using 40% cutoff. EZH2 expression was associated with aggressive histologic variants (65% vs. 29%, p < 0.001), high Ki-67 proliferation rate (median, 72% vs. 19%, p < 0.001), and p53 overexpression (43% vs. 2%, p < 0.001). EZH2 expression did not correlate with expression of other PRC2 components (EED and SUZ12), H3K27me3, MHC-I, and MHC-II. Patients with EZH2 expression (EZH2+) had a poorer overall survival (OS) compared with patients without EZH2 expression (EZH2-) (median OS: 3.9 years versus 9.4 years, respectively, p < 0.001). EZH2 expression also predicted a poorer prognosis in MCL patients with classic histology (median OS, 4.6 years for EZH2+ and 9.6 years for EZH2-negative, respectively, p < 0.001) as well as aggressive histology (median OS, 3.7 years for EZH2+ and 7.9 years for EZH2-negative, respectively, p = 0.046). However, EZH2 expression did not independently correlate with overall survival in a multivariate analysis. Gene expression analysis and pathway enrichment analysis demonstrated a significant enrichment in cell cycle and mitotic transition pathways in MCL with EZH2 expression. EZH2 expression detected by immunohistochemistry is present in 38% of MCL cases and it is associated with high proliferation rate, p53 overexpression, aggressive histologic variants, and poorer OS. Based on gene expression profiling data, EZH2 expression could potentiate cell cycle machinery in MCL. These data suggest that assessment of EZH2 expression could be useful to stratify MCL patients into low- and high-risk groups.
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Biomarcadores Tumorais/análise , Proteína Potenciadora do Homólogo 2 de Zeste/análise , Linfoma de Célula do Manto/enzimologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Proliferação de Células , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Histonas/análise , Humanos , Imuno-Histoquímica , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/mortalidade , Linfoma de Célula do Manto/terapia , Masculino , Metilação , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Medição de Risco , Fatores de Risco , Fatores de Tempo , Transcriptoma , Resultado do TratamentoRESUMO
BACKGROUND: The COVID-19 pandemic necessarily changed pre-medical students' educational environment into an online format-and students' subjective happiness (SH) is highly impacted by their educational environment. This study investigates changes in pre-medical students' perceptions of their educational environment and their SH before and after the pandemic, as well as explores the predictors related to their SH. METHODS: The Korean version of the Dundee Ready Educational Environment Measure (DREEM) questionnaire and single-item measures of SH and professional identity (PI) were used. The t-test was employed to analyze the differences of the SH, PI, and DREEM subscales scores before and after the onset of COVID-19. Cohen's d was used as effect size and correlations between SH and different subscales of DREEM were analyzed using Pearson's correlation. The multiple regression analysis was performed to reveal associations between predictors and SH. RESULTS: A total of 399 pre-medical students completed the survey both before and after the COVID-19 pandemic. The DREEM scores and all subscales scores significantly increased but each presents a different effect size. Students' Perceptions of Learning (SPL: Cohen's d = 0.97), Students' Perceptions of Teaching (SPT: Cohen's d = 1.13), and Students' Perceptions of Atmosphere (SPA: Cohen's d = 0.89) have large effect sizes. Students' Academic Self-Perceptions (SASP: Cohen's d = 0.66) have a medium effect size and Students' Social Self-Perceptions (SSSP: Cohen's d = 0.40) have a small effect size. In contrast, no significant change was noted in the SH and PI. Both PI and SSSP impacted SH before COVID-19, but after the pandemic, SH was impacted by SPL, SPA, and SSSP. CONCLUSIONS: Students' overall perception of their educational environment was more positive after the onset of COVID-19, but their social self-perceptions improved the least. Additionally, SSSP is the only predictor of SH both before and after the pandemic. The findings of this study suggest that educational institutions must pay attention to students' social relationships when trying to improve their educational environment. Furthermore, so as to increase students' SH, development of both educational environment and PI is essential.
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COVID-19 , Educação de Graduação em Medicina , Estudantes de Medicina , Felicidade , Humanos , Pandemias , SARS-CoV-2 , Inquéritos e QuestionáriosRESUMO
Highly flexible quasi solid-state batteries are promising in next-generation energy storage sectors due to their high energy density, power density, and low manufacturing cost. However, poor cycle life seriously limits their application in industrial sectors. Herein, a novel strategy is established to design the oxygenated cobalt vanadium selenide (O-Cox V1- x Se2 ) nanostructures for high-performance quasi solid-state (QSS) zinc-cobalt batteries (ZCBs) and zinc-air batteries (ZABs). Density functional theory (DFT) calculation reveals that the doping effect of Co2+ into O-VSe2 nanostructure could increase the density of states near the edge of the conduction band, demonstrating ultrafast electron transport kinetics. Most interestingly, the optimal O-Co0.33 V0.67 Se2 cathode-based QSS-ZCB exhibits an ultrahigh specific capacity of 422.7 mAh g-1 at a current density of 1 A g-1 , excellent energy density of 186.4 Wh kg-1 , tremendous power density of 5.65 kW kg-1 , and ultralong cycle life (86.9% capacity retention after 3000 cycles). Furthermore, O-Co0.33 V0.67 Se2 air-cathode based QSS-ZAB delivers a peak power density of 162 mW cm-2 and ultralong cycle life over 100 h. These experimental and theoretical studies indicate that the electrochemically induced, cobalt stabilizes the vanadium is essential to boost the energy storage properties and cycle life of both ZCBs and ZABs.