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Dual Flame-Retardant Mechanism-Assisted Suppression of Thermal Runaway in Lithium Metal Batteries with Improved Electrochemical Performances
No full textDespite considerable research efforts of lithium metal batteries (LMBs) in various aspects are performed, however the application as the power sources for transport vehicles remains challenging from the safety concerns and durability of LMBs. Therefore, to improve the safety and electrochemical performance of LMBs, a sophisticated separator composed of decabromodiphenyl ethane (DBDPE) and a CaO nanocomposite is engineered to concurrently impart the flame-retardant properties and enhance Li-ion transport. During normal operation, the coated CaO particles enhance the Li-ion transport, and the cycle performance of the LMB improves as the Li-metal cycling efficiency is enhanced without any side reactions. In contrast, under abnormal conditions, particularly at high temperatures, the coated CaO and DBDPE chemically react and act as fire extinguishers in the LMB. DBDPE exhibits gas-phase flame-retardant characteristics and forms HBr at high temperatures, which then subsequently reacts with CaO nanocrystals, forming CaBr2 with liquid-phase flame-retardant characteristics. Hence, both liquid- and gas-phase flame-retardant characteristics are observed in the DBDPE-CaO-coated polyethylene separator (DCPE) in the pouch-level LMB. The formation of the in situ halogen-based material in the LMB is attributed to a spontaneous chemical mechanism-based flame-retardant strategy. Consequently, the distinctive features of the DCPE separator improves the electrochemical performance and safety of LMBs.N
What do aid recipients want? Public attitudes toward foreign aid in developing countries
No full textIndividuals in developing countries are the ultimate end users of foreign aid. While the international donor community has emphasized the importance of aligning aid with recipient countries' preferences, the literature on public opinion and foreign aid has remained largely focused on donors. Using an original conjoint experiment conducted in seven developing countries, we examine the determinants of public attitudes toward foreign aid in recipient countries. We find that the characteristics of donor countries and foreign aid projects significantly influence recipient attitudes, often more than the size of the aid packages themselves. Individuals in recipient countries consistently prefer aid from democracies and donors with transparent aid agencies, as well as aid delivered by international organizations rather than directly from donor countries' aid agencies. These findings underscore the importance of multilateral aid agencies in aligning the preferences of donors and recipients.N
Methyl-oxazolomycin A: A novel oxazolomycin analog with potent selective estrogen receptor degrading activity in breast cancer cells
No full textBreast cancer (BC), the most prevalent malignancy in women worldwide, is categorized according to the expression of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) in tumor cells. Approximately 70% of all BCs are ER-positive and HER2-negative, and estrogen binding to the ER plays a vital role in BC development. We previously reported that methyl-oxazolomycin A, a natural compound isolated from Streptomyces sp. in soil, exhibited selective antiproliferative activity against ER-positive BC cells compared to triple-negative BC cells not expressing ER, PR, and HER2. The present study aimed to elucidate the molecular mechanisms underlying the antiproliferative activity of methyl-oxazolomycin A in two ER-positive BC lines, MCF-7 and T-47D. Methyl-oxazolomycin A effectively reduced the protein levels of ER alpha via proteasomal degradation while also reducing the protein levels of phosphorylated ER alpha. Notably, methyloxazolomycin A demonstrated potent antiproliferative activity in tamoxifen-resistant MCF-7 cells and down-regulated the protein expression of phosphorylated ER alpha at Tyr537, which SERDs such as fulvestrant fail to target. The antiproliferative activity of methyl-oxazolomycin A was associated with the induction of the G0/G1 cell cycle arrest through the modulation of cell cycle checkpoint protein expression. Prolonged treatment with methyloxazolomycin A led to an increase in the production of reactive oxygen species and induced apoptosis. These findings, which detail the mechanisms underlying the antiproliferative activity of methyl-oxazolomycin A, support its potential as a novel agent targeting ER-positive BC cells.N
Personality Traits, Impostor Phenomenon, and Workplace Bullying: A Cross-Sectional Study on Hospital Nurses
No full textBackgroundAlthough workplace bullying among nurses has long been recognized as a significant problem and solutions have been discussed, it still persists in nursing organizations. To gain a comprehensive understanding of this phenomenon, personal as well as workplace-related factors should be considered, and individual characteristics such as personality traits should be examined as potential factors of influence.PurposeThis study was developed to investigate the influence of personality traits and the impostor phenomenon on workplace bullying among nurses in tertiary hospitals.MethodsA cross-sectional research design was employed. Data were collected in December 2022 from 268 nurses working in tertiary hospitals in South Korea using an online survey. Personality traits, the impostor phenomenon, and workplace bullying were respectively assessed using the Big Five Inventory-short version, Clance Impostor Phenomenon Scale, and Negative Acts Questionnaire-Revised. Multiple linear regression analysis was conducted to identify the significant factors of influence on workplace bullying.ResultsA multiple linear regression analysis revealed the neuroticism personality trait and the impostor phenomenon to significantly influence workplace bullying, with higher levels of both factors associated with a more severe experience of workplace bullying.Conclusion/Implication for PracticeHigher levels of neuroticism were found significantly associated with both impostor phenomenon severity and experience of workplace bullying. Preventing workplace bullying and mitigating victimization require awareness of neuroticism in nurses and intervention strategies able to mitigate both the impostor phenomenon and neuroticism. Workplace bullying prevention policies should direct nursing leadership and management to develop and implement educational and intervention programs to help hospital nurses recognize their own personality traits and address their maladaptive impostor phenomenon proactively.N
Acid-Stable Palladium Catalyst for Low-Loading and High-Power-Density Proton-Exchange-Membrane Fuel Cells
No full textPd catalysts reach high activity and durability under alkaline conditions but exhibit significantly lower performance and durability compared with platinum under the acidic conditions of proton exchange membrane fuel cells (PEMFCs), which are more representative of practical industrial applications. To address this pragmatic challenge, we developed an acid-stable Pd catalyst with a small size of approximately 5 nm and a robust shell enriched with N defects using a facile method that controls the metal particle size and carbon shell thickness. This was made possible by varying the number of ligands and the oxidation state of Pd. When the catalyst was applied to practical cells, the current density was promoted 2.3 times compared to commercial Pd/C, and the peak power density reached 1009 mW/cm2. Furthermore, after 20,000 cycles, the catalytic activity decreased by only 20%, significantly outperforming previously reported Pd catalysts despite the low loading of 0.15 mg/cm2.N
Biallelic variants of SEMA3F are associated with nonsyndromic hearing loss
No full textIt is crucial to manage hearing loss and its associated public health impacts. In this study, we aimed to understand the role of Sema3f in the development and maintenance of the auditory system. Inner ear-specific Sema3f knockout mice exhibited hearing loss at 8 weeks with an elevated threshold for auditory brainstem response and an absent threshold for distortion product optoacoustic emission tests. Additionally, an increased number of outer hair cells and abnormal patterns of spiral ganglion neuron projections in the outer hair cell regions were observed. Through the analyses of sequencing data from 558 families with hearing loss, we identified biallelic variants of SEMA3F, which encodes semaphorin-3F, in one of the families. In the family, the proband showed profound progressive nonsyndromic hearing loss with congenital onset. In vitro analysis revealed that the identified missense variants decreased the furin-mediated processing of SEMA3F and abolished the cellular abilities of SEMA3F, which collapsed the filamentous actin cytoskeleton in human umbilical vein-derived endothelial cells. Our data suggest that SEMA3F is essential for normal hearing and is associated with nonsyndromic hearing loss in humans.<br /> (c) 2025 The Authors. Published by Elsevier Inc. on behalf of Korean Society for Molecular and Cellular Biology. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).Y
Data Assimilation of Satellite-Derived Arctic Sea-Ice Thickness During Boreal Summer
No full textReliable estimation and initialization of Arctic sea-ice thickness (SIT) through data assimilation (DA) during the summer melt season were previously hampered by the lack of available observations owing to limitations in satellite retrieval algorithms. Recently, successful satellite-derived Arctic SIT measurements from CryoSat-2 (CS2) and advanced microwave scanning radiometer 2 (AMSR2) during the boreal summer have been achieved using advanced retrieval algorithms. This study compares the impacts of CS2 and AMSR2 SIT datasets by individually assimilating each dataset using the ensemble optimal interpolation DA technique with CICE 5 dynamical sea-ice model in 2019 and 2020. The underestimated sea-ice extent in the control simulation without DA during summer was effectively corrected in the reanalysis assimilating AMSR2. However, the degree of correction was less pronounced in the reanalysis assimilating CS2. A sensitivity experiment confirmed that the weak correction degree when using CS2 was not due to its low spatiotemporal resolution, suggesting that the issues may arise from a systematic negative bias related to ice roughness over the central Arctic Ocean in CS2. During the summer and subsequent sea-ice growing seasons, the simulated SIT in the DA of AMSR2 shows greater similarity with independent reanalysis and satellite data than that of CS2. Validations against SIT observations measured by ice mass balance and upward-looking sonar indicate that the DA of AMSR2 effectively enhances the day-to-day variability compared with CS2 and control simulations during both the summer and subsequent winter seasons. This study underscores the response of the model to assimilating current satellite summer SIT data and highlights the factors to consider when utilizing these data.Y
Damnacanthal exerts anti-cancer effects in breast cancer cells via NAG-1 upregulation, CRM1 downregulation, and induction of autophagy
No full textBreast cancer continues to be a major cause of cancer-related deaths worldwide, emphasizing the urgent need for innovative treatments. This study investigates the anti-cancer potential of damnacanthal in breast cancer cell lines BT-20 and MCF-7, highlighting its regulatory effects on key biomarkers NAG-1 (Nonsteroidal Antiinflammatory Drug-Activated Gene-1) and CRM1 (Chromosome Region Maintenance 1). NAG-1 is recognized for its pro-apoptotic and anti-tumorigenic roles, while CRM1 is associated with oncogenic activity. We found that damnacanthal treatment significantly increased NAG-1 expression and decreased CRM1 expression in a dose- and time-dependent manner. Functional assays demonstrated that damnacanthal inhibited cell proliferation, reduced colony formation, and decreased tumor spheroid size. Mechanistically, luciferase reporter assays revealed that damnacanthal activates the -133 to +41 region of the NAG-1 promoter through C/EBP-beta. Real-time PCR and Western blotting analyses confirmed that NAG-1 is upregulated transcriptionally, whereas CRM1 is downregulated post-translationally via enhanced protein degradation, as evidenced by cycloheximide chase assays. Molecular docking suggested direct binding of damnacanthal to CRM1, potentially explaining its reduced stability. Additionally, damnacanthal induced autophagy by upregulating NAG-1, as indicated by increased LC3-II expression and autophagic flux, further confirmed by immunocytochemistry. These findings suggest that damnacanthal exerts potent anti-cancer effects by modulating NAG-1 and CRM1 expressions, inhibiting tumor cell growth, and inducing autophagy. This highlights its therapeutic potential as a novel agent for breast cancer treatment, warranting further clinical exploration.N
Rethinking Nuclear Deterrence in a Shifting Global Order: Theoretical, Empirical, and Policy Perspectives
No full textThis special issue examines the strategic choices and policy options for South Korea and the US in responding to North Koreas rising security challenges. With President Trump back in office and shifts in policy priorities, South Korea currently faces difficulties in establishing credible deterrence measures against North Korea. This introductory article provides theoretical discussions on nuclear deterrence and explores the complexities of achieving deterrence within the framework of asymmetric alliances, in which actors have the alliance dilemma—abandonment and entrapment risks. To better understand the three articles in this special issue, these theoretical discussions provide readers with necessary context, addressing various aspects of the alliance dilemma, public support for foreign policies, and alternative deterrence policy options, such as independent nuclearization and nuclear sharing agreements