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Extensive research has been conducted on hydrocarbon-based ionomers and membranes with high ionic conductivity and chemical stability for next-generation anion exchange membrane fuel cells (AEMFCs). However, it is well known that the benzene groups of hydrocarbon-based ionomers seriously poison the active sites of Pt catalysts, thereby reducing hydrogen oxidation reaction (HOR) activity and AEMFC performance. Over the past years, the development of benzene-tolerant catalysts has mainly focused on metal alloy nanoparticles such as PtRu, without pursuing the design of breakthrough catalyst structures that can more effectively reduce benzene poisoning. Here, we introduce an anti-poisoning catalyst structure promoted by the synergistic effect of carbon shell encapsulation and metal alloying. The porous carbon shell encapsulating the metal nanoparticles is expected to prevent direct adsorption of benzene groups, while the alloying of Pt and Ru can reduce the benzene adsorption energy itself. Comparative electrochemical analysis results confirm that the carbon shell-encapsulated metal alloy catalyst significantly alleviate benzene poisoning, exhibiting superior HOR activity than the conventional alloys in benzyltrimethylammonium hydroxide (BTMAOH) solution.

Abstract Polymer electrolyte membrane fuel cells (PEMFCs) suffer from severe performance degradation when operating under harsh conditions such as fuel starvation, shut‐down/start‐up, and open circuit voltage. A fundamental solution to these technical issues requires an integrated approach rather than condition‐specific solutions. In this study, an anode catalyst based on Pt nanoparticles encapsulated in a multifunctional carbon layer (MCL), acting as a molecular sieve layer and protective layer is designed. The MCL enabled selective hydrogen oxidation reaction on the surface of the Pt nanoparticles while preventing their dissolution and agglomeration. Thus, the structural deterioration of a membrane electrode assembly can be effectively suppressed under various harsh operating conditions. The results demonstrated that redesigning the anode catalyst structure can serve as a promising strategy to maximize the service life of the current PEMFC system.

Abstract This study investigated the feature importance of near-infrared spectra from random forest regression models constructed to predict the carbonization characteristics of hydrochars produced by hydrothermal carbonization of kraft lignin. The model achieved high coefficients of determination of 0.989, 0.988, and 0.985 with root mean square errors of 0.254, 0.003, and 0.008 when predicting the carbon content, atomic O/C ratio, and H/C ratio, respectively. The random forest models outperformed the multilayer perceptron models for all predictions. In the feature importance analysis, the spectral regions at 1600–1800 nm, the first overtone of C–H stretching vibrations, and 2000–2300 nm, the combination bands, were highly important for predicting the carbon content and O/C predictions, whereas the region at 1250–1711 nm contributed to predicting H/C. The random forest models trained with the high-importance regions achieved better prediction performances than those trained with the entire spectral range, demonstrating the usefulness of the feature importance yielded by the random forest and the feasibility of selective application of the spectral data.

Membrane electrode assembly (MEA) is an essential component that mainly determines the performance of proton exchange membrane fuel cells (PEMFCs). In the electrodes of the MEA, ionomers are mixed with Pt-based nanoparticles to transfer protons to the Pt surface where electrochemical reactions take place. However, Pt catalysts suffer from the poisoning effect of ionomers with proton-conducting groups such as sulfonic acid (SA), resulting in performance deterioration. In particular, for emerging hydrocarbon-based ionomers, the benzene group, which is commonly used to improve their chemical structure, accelerates the poisoning effect. Herein, we experimentally simulate the adsorption of SA and benzenesulfonic acid (BSA) on Pt nanoparticles, revealing the orientation-dependent poisoning effect of BSA on the Pt surface.

Polymer electrolyte membrane fuel cells (PEMFCs) have attracted much attention as highly efficient, eco-friendly energy conversion devices. However, carbon-supported Pt (Pt/C) catalysts for PEMFCs still have several problems, such as low long-term stability, to be widely commercialized in fuel cell applications. To address the stability issues of Pt/C such as the dissolution, detachment, and agglomeration of Pt nanoparticles under harsh operating conditions, we design an interesting fabrication process to produce a highly active and durable Pt catalyst by introducing a robust carbon shell on the Pt surface. Furthermore, this approach provides insights into how to regulate the carbon shell layer for fuel cell applications. Through the application of an appropriate amount of H2 gas during heat treatment, the carbon shell pores, which are integral to the structure, can be systematically modulated to facilitate oxygen adsorption for the oxygen reduction reaction. Simultaneously, the carbon shell functions as a protective barrier, preventing catalyst degradation. In this regard, we investigate an in-depth analysis of the effects of critical parameters including H2 content and the flow rate of H2/N2 mixed gas during heat treatment to prepare better catalysts.

Aminoacyl-tRNA synthetases possess unique domains. In this study the structure of the vertebrate IARS1 and EARS1 complex reveals that vertebrate IARS1 protects the DNA repair factor BRCA1 from proteolytic degradation via its UBX-fold domain.

A carboxymethyl cellulose (CMC)/polyethyleneimine (PEI) hybrid hydrogel was successfully prepared under green processing conditions. The CMC and PEI formed a polyelectrolyte complex, and the three-dimensional (3D) network structure was hardened by chemical crosslinking, resulting in suitable hydrogel properties. In the prepared CMC/PEI polyelectrolyte hydrogel, the surface charge was easily switched according to the pH change, and the resulting swelling and contraction was reversible. The pH sensitivity of the CMC/PEI hydrogel was effective in removing ionic dye contaminants, and as a result, it showed an excellent removal capacity of 319 mg/g for anionic acid orange (AO) and 129 mg/g for cationic methylene blue (MB). In addition, the CMC/PEI polyelectrolyte hydrogel maintained structural stability despite repeated changes in surface charge characteristics and shrinkage-swelling due to repeated pH conversion. As a result, in the reuse process through repeated adsorption and desorption, it showed an excellent reuse efficiency of more than 93% even after 10 reuse cycles.

Abstract One of the primary challenges in relation to phosphoric acid fuel cells is catalyst poisoning by phosphate anions that occurs at the interface between metal nanoparticles and the electrolyte. The strong adsorption of phosphate anions on the catalyst surface limits the active sites for the oxygen reduction reaction (ORR), significantly deteriorating fuel cell performance. Here, antipoisoning catalysts consisting of Pt‐based nanoparticles encapsulated in an ultrathin carbon shell that can be used as a molecular sieve layer are rationally designed. The pore structure of the carbon shells is systematically regulated at the atomic level by high‐temperature gas treatment, allowing O2 molecules to selectively react on the active sites of the metal nanoparticles through the molecular sieves. Besides, the carbon shell, as a protective layer, effectively prevents metal dissolution from the catalyst during a long‐term operation. Consequently, the defect‐controlled carbon shell leads to outstanding ORR activity and durability of the hybrid catalyst even in phosphoric acid electrolytes.

Proton exchange membrane fuel cells (PEMFCs) face technical issues of performance degradation due to catalyst dissolution and agglomeration in real-world operations. To address these challenges, intensive research has been recently conducted to introduce additional structural units on the catalyst surface. Among various concepts for surface modification, carbon shell encapsulation is known to be a promising strategy since the carbon shell can act as a protective layer for metal nanoparticles. As an interesting approach to form carbon shells on catalyst surfaces, the precursor ligand-induced formation is preferred due to its facile synthesis and tunable control over the carbon shell porosity. However, the origin of the carbon source and the carbon shell formation mechanism have not been studied in depth yet. Herein, this study aims to investigate carbon sources through the use of different precursors and the introduction of new methodologies related to the ligand exchange phenomenon. Subsequently, we provide new insights into the carbon shell formation mechanism using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Finally, the thermal stability and electrochemical durability of carbon shells are thoroughly investigated through in situ transmission electron microscopy (in situ TEM) and accelerated durability tests.

The development of non−Pt or carbon−based catalysts for anion exchange membrane fuel cells (AEMFCs) requires identification of the active sites of the catalyst. Since not only metals but also carbon materials exhibit oxygen reduction reaction (ORR) activity in alkaline conditions, the contribution of carbon-based materials to ORR performance should also be thoroughly analyzed. However, the conventional CN− poisoning experiments, which are mainly used to explain the main active site of M−N−C catalysts, are limited to only qualitative discussions, having the potential to make fundamental errors. Here, we report a modified electrochemical analysis to quantitatively investigate the contribution of the metal and carbon active sites to ORR currents at a fixed potential by sequentially performing chronoamperometry with two reaction inhibitors, CN− and benzyl trimethylammonium (BTMA+). As a result, we discover how to quantify the individual contributions of two active sites (Pt nanoparticles and carbon support) of carbon−supported Pt (Pt/C) nanoparticles as a model catalyst. This study is expected to provide important clues for the active site analysis of carbon-supported non−Pt catalysts, such as M−N−C catalysts composed of heterogeneous elements.

Background Medical students need to receive training in providing smoking cessation counseling to provide effective smoking cessation interventions to smokers when they become doctors. This study examined the smoking cessation education curricula and factors affecting counseling self-efficacy (CSE) in smoking cessation treatment among medical students. Methods In a multicenter cross-sectional study, we obtained demographic information, personal history of tobacco use and intention to quit smoking, exposure to secondhand smoke in the school premises during the past week, the experience of learning about tobacco in each medical school, tobacco-related medical knowledge, and self-efficacy in smoking cessation counseling on medical students of four Korean medical schools. Results Among 1,416 medical students eligible, 313 (22.1%) students completed a self-administered questionnaire. Only 20.3% of the students reported positive CSE on smoking cessation. The factors affecting positive CSE were scores of ≥ 60 on tobacco-related medical knowledge, smoking experience, and blended learning (p = 0.014, 0.005, and 0.015, respectively). Conclusion This study shows that high scores in tobacco-related medical knowledge and blended learning are correlated with positive CSE for smoking cessation counseling.

Auriculotherapy has been extensively used for chronic spontaneous urticaria in China. However, the evidence of its effectiveness and safety for the treatment of chronic spontaneous urticaria is insufficient. Hence, we conducted this study to compare auriculotherapy or auriculotherapy joint treatment with Western medicine for the cure of chronic spontaneous urticaria. This meta-analysis of seven randomized controlled trials showed that auriculotherapy or auriculotherapy joint treatment was significantly superior to Western medicine in curing clinical signs and symptoms of chronic spontaneous urticaria [odds ration (OR), 2.61; 95% confidence interval (CI), 1.54–4.43; p = 0.0004) and also better in total effect rate (OR, 3.81; 95% CI, 2.07–7.01; p＜0.0001). But, auriculotherapy or auriculotherapy joint treatment was similar to Western medicine in improving clinical signs and symptoms of chronic spontaneous urticaria (OR, 0.74; 95% CI, 0.35–1.56; p = 0.42). Auriculotherapy or auriculotherapy joint treatment was safer than Western medicine for curing chronic spontaneous urticaria (OR, 0.26; 95% CI, 0.09–0.80; p = 0.02). Auriculotherapy alone or auriculotherapy joint treatment appears to be more effective and safer than Western medicine that contains antihistamines in the treatment of chronic spontaneous urticaria. However, these findings should be interpreted with caution due to the unclear risk bias of methodological quality, and further studies with large-scale, better, and more rigorously designed protocol are necessary to prove these findings. Keywords: auricular acupuncture, auriculotherapy, urticaria, review, meta-analysis

The Eastern Mediterranean Region (EMR) is witnessing an increase in chronic disorders, including mental illness. With ongoing unrest, this is expected to rise. This is the first study to quantify the burden of mental disorders in the EMR. We used data from the Global Burden of Disease study (GBD) 2013. DALYs (disability-adjusted life years) allow assessment of both premature mortality (years of life lost-YLLs) and nonfatal outcomes (years lived with disability-YLDs). DALYs are computed by adding YLLs and YLDs for each age-sex-country group. In 2013, mental disorders contributed to 5.6% of the total disease burden in the EMR (1894 DALYS/100,000 population): 2519 DALYS/100,000 (2590/100,000 males, 2426/100,000 females) in high-income countries, 1884 DALYS/100,000 (1618/100,000 males, 2157/100,000 females) in middle-income countries, 1607 DALYS/100,000 (1500/100,000 males, 1717/100,000 females) in low-income countries. Females had a greater proportion of burden due to mental disorders than did males of equivalent ages, except for those under 15 years of age. The highest proportion of DALYs occurred in the 25-49 age group, with a peak in the 35-39 years age group (5344 DALYs/100,000). The burden of mental disorders in EMR increased from 1726 DALYs/100,000 in 1990 to 1912 DALYs/100,000 in 2013 (10.8% increase). Within the mental disorders group in EMR, depressive disorders accounted for most DALYs, followed by anxiety disorders. Among EMR countries, Palestine had the largest burden of mental disorders. Nearly all EMR countries had a higher mental disorder burden compared to the global level. Our findings call for EMR ministries of health to increase provision of mental health services and to address the stigma of mental illness. Moreover, our results showing the accelerating burden of mental health are alarming as the region is seeing an increased level of instability. Indeed, mental health problems, if not properly addressed, will lead to an increased burden of diseases in the region.

This meta-analysis investigated current trends in generative AI research in L2 and Korean language education internationally and domestically, aiming to guide future educational directions. Domestically, most studies focused on university students, with fewer studies on middle and high school students, elementary students, and teachers. Similarly, international studies also predominantly focused on university students. In Korean language education, research primarily involved adult learners, highlighting the effective use of AI tools with intermediate to advanced learners. Analysis of participant numbers revealed that most studies in English and Korean education involved 11-50 participants. Methodologically, many studies in English and Korean education employed quantitative methods, whereas international studies used qualitative approaches. Research on language skills predominantly focused on participant perceptions, with subsequent emphasis on speaking and writing. However, there were significant gaps in studies addressing listening and grammar skills. As a result of a comprehensive analysis of language skills, the research emphasized the area of writing, revealing that learners generally exhibited positive perceptions across the studies. To maximize the educational value of ChatGPT, it is crucial to teach students effective questioning techniques. Future research should focus on specific prompt usage methods and enhance self-directed learning using metacognitive strategies. [ABSTRACT FROM AUTHOR]