Progress of Metal Chalcogenides as Catalysts for Efficient Electrosynthesis of Hydrogen Peroxide.

Hydrogen peroxide (H2O2) is a high-demand chemical, valued as a powerful and eco-friendly oxidant for various industrial applications. The traditional industrial method for producing H2O2, known as the anthraquinone process, is both costly and environmentally problematic. Electrochemical synthesis, which produces H2O2 using electricity, offers a sustainable alternative, particularly suited for small-scale, continuous on-site H2O2 generation due to the portability of electrocatalytic devices. For efficient H2O2 electrosynthesis, electrocatalysts must exhibit high selectivity, activity, and stability for the two-electron pathway-oxygen reduction reaction (2e- ORR). Transition-metal chalcogenide (TMC)-based materials have emerged as promising candidates for effective 2e- ORR due to their high activity in acidic environments and the abundance of their constituent elements. This review examines the potential of TMC-based catalysts in H2O2 electrosynthesis, categorizing them into noble-metal and non-noble-metal chalcogenides. It underscores the importance of achieving high selectivity, activity, and stability in 2e- ORR. By reviewing recent advancements and identifying key challenges, this review provides valuable insights into the development of TMC-based electrocatalysts for sustainable H2O2 production.

Indirect-to-direct bandgap transition in GaP semiconductors through quantum shell formation on ZnS nanocrystals.

Although GaP, a III-V compound semiconductor, has been extensively utilized in the optoelectronic industry for decades as a traditional material, the inherent indirect bandgap nature of GaP limits its efficiency. Here, we demonstrate an indirect-to-direct bandgap transition of GaP through the formation of quantum shells on the surface of ZnS nanocrystals. The ZnS/GaP quantum shell with a reverse-type I heterojunction, consisting of a monolayer-thin GaP shell grown atop a ZnS core, exhibits a record-high photoluminescence quantum yield of 45.4% in the violet emission range (wavelength = 409 nm), validating its direct bandgap nature. Density functional theory calculations further reveal that ZnS nanocrystals, as the growth platform for GaP quantum shells, play a crucial role in the direct bandgap formation through hybridization of electronic states with GaP. These findings suggest potential for achieving direct bandgaps in compounds that are constrained by their inherent indirect energy gaps, offering a strategy for tailoring energy structures to significantly improve efficiencies in optoelectronics and photovoltaics.

Chiral 3D structures through multi-dimensional transfer printing of multilayer quantum dot patterns.

Three-dimensional optical nanostructures have garnered significant interest in photonics due to their extraordinary capabilities to manipulate the amplitude, phase, and polarization states of light. However, achieving complex three-dimensional optical nanostructures with bottom-up fabrication has remained challenging, despite its nanoscale precision and cost-effectiveness, mainly due to inherent limitations in structural controllability. Here, we report the optical characteristics of intricate two- and three-dimensional nanoarchitectures made of colloidal quantum dots fabricated with multi-dimensional transfer printing. Our customizable fabrication platform, directed by tailored interface polarity, enables flexible geometric control over a variety of one-, two-, and three-dimensional quantum dot architectures, achieving tunable and advanced optical features. For example, we demonstrate a two-dimensional quantum dot nanomesh with tuned subwavelength square perforations designed by finite-difference time-domain calculations, achieving an 8-fold enhanced photoluminescence due to the maximized optical resonance. Furthermore, a three-dimensional quantum dot chiral structure is also created via asymmetric stacking of one-dimensional quantum dot layers, realizing a pronounced circular dichroism intensity exceeding 20°.

Synthesis and surface engineering of Ag chalcogenide quantum dots for near-infrared biophotonic applications.

Quantum dots (QDs), a novel category of semiconductor materials, exhibit extraordinary capabilities in tuning optical characteristics. Their emergence in biophotonics has been noteworthy, particularly in bio-imaging, biosensing, and theranostics applications. Although conventional QDs such as PbS, CdSe, CdS, and HgTe have garnered attention for their promising features, the presence of heavy metals in these QDs poses significant challenges for biological use. To address these concerns, the development of Ag chalcogenide QDs has gained prominence owing to their near-infrared emission and exceptionally low toxicity, rendering them suitable for biological applications. This review explores recent advancements in Ag chalcogenide QDs, focusing on their synthesis methodologies, surface chemistry modifications, and wide-ranging applications in biomedicine. Additionally, it identifies future directions in material science, highlighting the potential of these innovative QDs in revolutionizing the field.

Asymmetric Metal-Carboxylate Complexes for Synthesis of InGaP Alloyed Quantum Dots with Blue Emission.

Indium phosphide (InP) quantum dots (QDs) have attracted significant interest as next-generation light-emitting materials. However, the synthesis of blue-emitting InP-based QDs has lagged behind that of established green- and red-emitting InP QDs. Herein, we present a strategy to synthesize blue-emitting QDs by forming an InGaP alloy composition. The introduction of asymmetric In-carboxylate and Ga-carboxylate complexes resulted in a balanced synthetic reactivity between In-P and Ga-P, leading to the formation of InGaP alloyed QDs. The resultant In1-xGaxP alloyed QDs exhibited a broad range of photoluminescence (PL) tunability, spanning from 535 nm (InP) to 465 nm (In0.62Ga0.38P), depending on the In/Ga ratio used in the synthesis. In contrast, synthesis with symmetric In-carboxylate and Ga-carboxylate complexes produced a core/shell structure of InP/GaP QDs, which did not exhibit a blue shift of the PL peak with Ga addition. By employing a core/shell structure of In0.62Ga0.38P/ZnS QDs, we achieved a PL quantum yield of 42% at 475 nm. This work highlights the material-processing strategy essential for forming alloyed structures in III-V ternary systems.

Differential trends and patterns of sociodemographic disparities in burden of mental disorders, substance use disorder and self-harm across age groups: ecological study in 204 countries using the Global Burden of Disease Study 2019.

BACKGROUND: It is well-known that socioeconomic status is associated with mental illness at both the individual and population levels, but there is a less clear understanding of whether socioeconomic development is related to poor mental health at the country level. AIMS: We aimed to investigate sociodemographic disparities in burden of mental disorders, substance use disorders and self-harm by age group. METHOD: Estimates of age-specific disability-adjusted life years (DALY) rates for mental disorders, substance use disorders and self-harm from 1990 to 2019 for 204 countries were obtained. The sociodemographic index (SDI) was used to assess sociodemographic development. Associations between burden of mental health and sociodemographic development in 1990 and 2019 were investigated, and sociodemographic inequalities in burden of mental health from 1990 to 2019 by age were estimated using the concentration index. RESULTS: Differential trends in sociodemographic disparities in diseases across age groups were observed. For mental disorders, particularly depressive disorder and substance use disorders, DALY rates in high SDI countries were higher and increased more than those in countries with other SDI levels among individuals aged 10-24 and 25-49 years. By contrast, DALY rates for those over 50 years were lower in high SDI countries than in countries with other SDI levels between 1990 and 2019. A higher DALY rate among younger individuals accompanied a higher SDI at the country level. However, increased sociodemographic development was associated with decreased disease burden for adults aged ≥70 years. CONCLUSIONS: Strategies for improving mental health and strengthening mental health system should consider a broader sociocultural context.

Injectable composite hydrogels embedded with gallium-based liquid metal particles for solid breast cancer treatment via chemo-photothermal combination.

Photothermal therapy (PTT) holds great promise as a cancer treatment modality by generating localized heat at the tumor site. Among various photothermal agents, gallium-based liquid metal (LM) has been widely used as a new photothermal-inducible metallic compound due to its structural transformability. To overcome limitations of random aggregation and dissipation of administrated LM particles into a human body, we developed LM-containing injectable composite hydrogel platforms capable of achieving spatiotemporal PTT and chemotherapy. Eutectic gallium-indium LM particles were first stabilized with 1,2-Distearoyl-sn­glycero-3-phosphoethanolamine (DSPE) lipids. They were then incorporated into an interpenetrating hydrogel network composed of thiolated gelatin conjugated with 6-mercaptopurine (MP) chemodrug and poly(ethylene glycol)-diacrylate. The resulted composite hydrogel exhibited sufficient capability to induce MDA-MB-231 breast cancer cell death through a multi-step mechanism: (1) hyperthermic cancer cell death due to temperature elevation by near-infrared laser irradiation via LM particles, (2) leakage of glutathione (GSH) and cleavage of disulfide bonds due to destruction of cancer cells. As a consequence, additional chemotherapy was facilitated by GSH, leading to accelerated release of MP within the tumor microenvironment. The effectiveness of our composite hydrogel system was evaluated both in vitro and in vivo, demonstrating significant tumor suppression and killing. These results demonstrate the potential of this injectable composite hydrogel for spatiotemporal cancer treatment. In conclusion, integration of PTT and chemotherapy within our hydrogel platform offers enhanced therapeutic efficacy, suggesting promising prospects for future clinical applications. STATEMENT OF SIGNIFICANCE: Our research pioneers a breakthrough in cancer treatments by developing an injectable hydrogel platform incorporating liquid metal (LM) particle-mediated photothermal therapy and 6-mercaptopurine (MP)-based chemotherapy. The combination of gallium-based LM and MP achieves synergistic anticancer effects, and our injectable composite hydrogel acts as a localized reservoir for specific delivery of both therapeutic agents. This platform induces a multi-step anticancer mechanism, combining NIR-mediated hyperthermic tumor death and drug release triggered by released glutathione from damaged cancer populations. The synergistic efficacy validated in vitro and in vivo studies highlights significant tumor suppression. This injectable composite hydrogel with synergistic therapeutic efficacy holds immense promise for biomaterial-mediated spatiotemporal treatment of solid tumors, offering a potent targeted therapy for triple negative breast cancers.

Living longer but in poor health: healthcare system responses to ageing populations in industrialised countries based on the Findings from the Global Burden of Disease Study 2019.

OBJECTIVES: This study aimed to examine changes in life expectancy (LE), health-adjusted life expectancy (HALE), unhealthy years of life, and disease burden of older people in industrialised countries and associations with health systems. METHODS: We used estimates of LE and HALE, unhealthy years of life, years of life loss (YLL), years lived with disability (YLD) for individuals aged 70 years and over in 33 industrialised countries from 1990 to 2019 from the Global Burden of Disease Study 2019. A linear regression analysis was conducted to examine the association of health outcomes with the Healthcare Access and Quality (HAQ) index. RESULTS: LE and HALE increased with improved HAQ index from 1990 to 2019. However, the number of unhealthy years of life increased. An increased HAQ index was associated with decreases in YLL. However, changes in YLD were relatively small and were not correlated with HAQ index. CONCLUSIONS: The healthcare system needs to more address the increased morbidity burden among older people. It should be designed to handle to healthcare needs of the ageing population.

Suicide risk of chronic diseases and comorbidities: A Korean case-control study.

OBJECTIVES: Chronic diseases including mental disorders have been associated with suicide. This study broadens the approach by incorporating a comprehensive list of chronic diseases and a context of comorbidities and explored their associations with suicide. METHODS: Data-linkage between death registry and Korean National Health Insurance data was conducted. Suicide cases (n = 64,099) between 2009 and 2013 were 1:4 matched for gender and age to an alive control (n = 256,396). A total of 92 individual diseases of 9 broad categories were identified from insurance claims data. Conditional logistic regression was applied to assess the associations, adjusting for mental and behavioral disorders and socioeconomic status. RESULTS: Suicide cases frequently experienced chronic diseases (90.0 %) and comorbidities (74.6 %). Chronic diseases greatly increased suicide risk and, among these, mental and behavioral disorders showed the highest suicide risk (OR = 7.53, 95 % CI = 7.32-7.74) followed by cardiovascular (OR = 3.36, 95 % CI = 3.26-3.47). For individual diseases, gastritis and duodenitis were most prevalent (68.1 %) among suicide cases but depressive disorder showed the highest risk (OR = 4.95, 95 % CI = 4.79-5.12). Suicide risk was strong in comorbid status sometimes comparable to odds for mental and behavioral disorder alone (e.g., OR for cardiovascular and eye vision-related diseases = 4.01, 95 % CI = 3.86-4.17). LIMITATIONS: Differentiation of comorbidity was limited to pairs between major disease categories, neglecting the heterogeneity within categories. CONCLUSION: Chronic diseases, in particular comorbidity, showed strong associations with suicide. This suggests that those with comorbidities feel that they are pushed to the extreme line, supporting comprehensive interventions for them to address wider reasons including psychological and social problems, besides medical problems.

Modulating the folding and binding of peptides using a stimuli-responsive molecular tweezer.

This study presents the development of a ß-hairpin (tryptophan zipper, Trpzip)-based molecular tweezer (MT) that can control the folding and binding of α-helical peptides. When an α-helix isolated from the p53 protein was conjugated with Trpzip in an optimized macrocyclic structure, the folded ß-hairpin stabilized the helix conformation through the side chain-to-side chain stapling strategy, which notably enhanced target (hDM2) affinity of the peptide. On the other hand, the helicity and binding affinity were significantly reduced when the hairpin was unfolded by a redox stimulus. This stimulus-responsive property was translated into the effective capture and release of model multivalent biomaterials, hDM2-gold nanoparticle conjugates. Since numerous protein interactions are mediated by α-helical peptides, these results suggest that the ß-hairpin-based MT holds great potential to be utilized in various biomedical applications, such as protein interaction inhibition and cancer biomarker (e.g., circulating tumor cells and exosomes) detection.

Correction: Trends and patterns of North Korea's disease burden from 1990 to 2019: Results from Global Burden of Disease study 2019.

[This corrects the article DOI: 10.1371/journal.pone.0277335.].

The burden of malaria in sub-Saharan Africa and its association with development assistance for health and governance: An exploration of the GBD 2019 study.

Even with a reduced burden of malaria in sub-Saharan Africa (SSA), differences remain in the rate of change among countries and sub-regions. We used data from the Global Burden of Disease Study 2019 to establish the relationship between Development Assistance for Health (DAH) and governance and trends in malaria burden in SSA. The trend was estimated using the Joinpoint regression program and the Institute of Health Metrics and Evaluation's DAH database, and World Bank Governance Indicators to analyze the DAH and governance respectively from 2000 to 2017 and used two-way fixed effects to establish their association with the trend in the period. The findings showed decreases in SSA's age-standardised rates for disability-adjusted life years (ASDR) (-47% (95% uncertainty interval (UI) -69% to -14%)), deaths (-38% (95% UI -65% to -3%)), incidence (-35% (95% UI -44% to -25%)), and prevalence (-34% (95% UI -43% to -24%)). Decreases in ASDR were associated with increases in DAH (ß -134.18, standard error (SE) 27.26) and governance scores (ß -246.19, SE 39.13). The association between reductions in malaria burden and increases in DAH and in governance scores shows the need for accelerated funding of malaria programs and advocacy for better disease governance in malaria-endemic countries.Abbreviations: APC: Annual percentage change; ASDR: Age-standardised disability-adjusted life-year rate; ASIR: Age-standardised incidence rate; ASIR: Age-standardised incidence rate; ASMR: Age-standardised mortality rate; CSSA: Central sub-Saharan Africa; DAH: Development Assistance for Health; DALYs: Disability-adjusted life years; ESSA: Eastern sub-Saharan Africa; GBD: Global burden of disease; GHDx Global Health Data Exchange; IHME: Institute of Health Metrics and Evaluation; SDGs: Sustainable Development Goals; SSA: Sub-Saharan Africa; SSSA: Southern sub-Saharan Africa; UNSD: United Nations Statistics Division; USD: United States dollars; WGI: World Bank Governance Indicators; WHO: World Health Organization; WSSA: Western sub-Saharan Africa.

The Trend of Healthcare Needs among Elders and Its Association with Healthcare Access and Quality in Low-Income Countries: An Exploration of the Global Burden of Disease Study 2019.

To investigate the trend of healthcare needs among elders in low-income countries (LICs) and how changes in healthcare access and quality (HAQ) have correlated with these changes from 1990 to 2019, this study used estimates from the global burden of disease (GBD) 2019 study, including prevalence, years of life lost (YLLs), years lived with disability (YLDs), life expectancy (LE), health-adjusted life expectancy (HALE) and the HAQ index for years 1990 and 2019. We found increases in numbers of YLLs, YLDs, and prevalent cases due to NCDs, and the rate of increase was higher for all indicators of non-communicable diseases (NCDs) when compared with communicable, maternal, neonatal and nutritional diseases among elders. We also observed increases in LE and HALE among all countries. However, this was also challenged by increases in unhealthy life years (ULYs) and their constant percentage of LE. The HAQ index of LICs was also found to be low, although it had increased during the period. A reduction in the burden of acute diseases explains the increase in LE, but increases in ULYs and the NCD burden were also observed. LICs need to improve their HAQ to counter the growing threat of longer but less healthy lives.

Changes in contributions of age- and cause-specific mortality to the widening life expectancy gap between North and South Korea, 1990-2019: An analysis of the Global Burden of Disease Study 2019.

Background: Life expectancy gaps between North and South Korea have increased but contributions to these gaps remain poorly understood. Using data from the Global Burden of Disease Study (GBD) 2019, we examined how much death from specific diseases contributed to these gaps in different age groups over three decades. Methods: Data for death numbers and population by sex and 5-year age groups in both North and South Korea from 1990 to 2019 were extracted from the GBD 2019 to calculate life expectancy. Joinpoint regression analysis was conducted to investigate changes in life expectancy in North and South Korea. We used decomposition analysis to partition differences in life expectancy within and between the two Koreas into changes in age- and cause-specific death contributions. Results: Life expectancy increased in two Koreas from 1990 to 2019, but North Korea experienced a marked decline in life expectancy during the mid-1990s. The life expectancy gaps between the two Koreas were greatest in 1999, with a difference of 13.3 years for males and 14.9 years for females. The main contributors to these gaps were higher under-5 mortality from nutritional deficiencies for males (4.62 years) and females (4.57 years) in North Korea, accounting for about 30% of the total gap in life expectancy. After 1999, the life expectancy gaps reduced but persisted with differences of about ten years by 2019. Notably, chronic diseases contributed to about 8 out of 10 years of life expectancy gap between the two Koreas in 2019. Differential cardiovascular disease mortality in the older groups was the main contributor to the life expectancy gap. Conclusions: The contributors to this gap have shifted from nutritional deficiencies in children younger than five years to cardiovascular disease among elderly people. Efforts for strengthening social and healthcare systems are needed to curb this large gap.

Sequential Co-Passivation in InAs Colloidal Quantum Dot Solids Enables Efficient Near-Infrared Photodetectors.

III-V colloidal quantum dots (CQDs) are promising materials for optoelectronic applications, for they avoid heavy metals while achieving absorption spanning the visible to the infrared (IR). However, the covalent nature of III-V CQDs requires the development of new passivation strategies to fabricate conductive CQD solids for optoelectronics: this work shows herein that ligand exchanges, previously developed in II-VI and IV-VI quantum dots and employing a single ligand, do not fully passivate CQDs, and that this curtails device efficiency. Guided by density functional theory (DFT) simulations, this work develops a co-passivation strategy to fabricate indium arsenide CQD photodetectors, an approach that employs the combination of X-type methyl ammonium acetate (MaAc) and Z-type ligands InBr3 . This approach maintains charge carrier mobility and improves passivation, seen in a 25% decrease in Stokes shift, a fourfold reduction in the rate of first-exciton absorption linewidth broadening over time-under-stress, and leads to a doubling in photoluminescence (PL) lifetime. The resulting devices show 37% external quantum efficiency (EQE) at 950 nm, the highest value reported for InAs CQD photodetectors.

Long-term trajectories of suicide ideation and its socioeconomic predictors: A longitudinal 8-year follow-up study.

OBJECTIVE: Suicide ideation is the first stage of suicide behavior, and the long-term course of suicide ideation is highly variable. The aim of this study is to identify trajectories of suicide ideation over an 8-year period and explore the association of socioeconomic status (SES) with suicide ideation trajectories. METHODS: We included 10,017 participants from Waves 7-15 of the Korea Welfare Panel Study; these have data on suicidal ideation (2012-2020). Trajectories analysis was conducted to identify distinct trajectories of suicidal ideation. Multinomial logistic regression was used to examine associations of SES with suicidal ideation trajectories. The interaction effects between current SES and prospective economic condition on trajectories were examined using a synergy index (SI). RESULTS: We identified three suicide ideation trajectory groups: low-stable, moderate-decreasing, and high-persistent. Individuals in both moderate-decreasing and high-persistent trajectories had poorer current SES and prospective economic conditions than low-stable trajectories. Interestingly, those reporting poorer prospective economic conditions had a greater risk of being in a high-persistent trajectory than being in a moderate-decreasing trajectory. Further, individuals with poorer current SES and prospective economic conditions were more likely to be in the high-persistent trajectory. CONCLUSIONS: Our findings demonstrated three distinct trajectories of suicide ideation which provide useful information for specific preventive interventions that could be developed. Moreover, poor prospective economic condition is a significant predictor of the high-persistent suicide ideation trajectory. Supporting economic difficulties and helping make goals and plans to strengthen positive thinking would help attenuate suicidal ideation and prevent suicidal behavior.

Ultrahigh-resolution quantum dot patterning for advanced optoelectronic devices.

Quantum dots have attracted significant scientific interest owing to their optoelectronic properties, which are distinct from their bulk counterparts. In order to fully utilize quantum dots for next generation devices with advanced functionalities, it is important to fabricate quantum dot colloids into dry patterns with desired feature sizes and shapes with respect to target applications. In this review, recent progress in ultrahigh-resolution quantum dot patterning technologies will be discussed, with emphasis on the characteristic advantages as well as the limitations of diverse technologies. This will provide guidelines for selecting suitable tools to handle quantum dot colloids throughout the fabrication of quantum dot based solid-state devices. Additionally, epitaxially fabricated single-particle level quantum dot arrays are discussed. These are extreme in terms of pattern resolution, and expand the potential application of quantum dots to quantum information processing.

Financial Hardship, Depression, and Self-Esteem: Temporal Analysis Using a Korean Panel Study.

OBJECTIVE: Financial hardship influences depression risk, however, the pathway of the effect of financial hardship on depression and the role of self-esteem remain unclear. This study examined whether changes in financial hardship affected depression, and whether self-esteem mediated by this relationship. METHODS: Data from 99,588 observations of 15,331 individuals were extracted from 10 waves of the Korean Welfare Panel Study. The association between changes in financial hardship and depression was investigated using a generalized estimation equation, and the extent to which these associations were mediated by self-esteem was assessed. RESULTS: The results indicated that changes in financial hardship were associated with depression, with varying magnitude. Experiencing severe financial hardship over two consecutive years (odds ratio [OR]: 3.87, 95% confidence interval [CI]=3.09-4.85) or increased financial hardship over the previous year strongly influenced depression (e.g., OR: 3.88, 95% CI=3.09-4.86 for low financial hardship at t-1 year and high at t year). Self-esteem plays a mediating role in the relationship between changes in financial hardship and depression, where persistent financial hardship is associated with low self-esteem, leading to depression. CONCLUSION: These findings highlighted the importance of monitoring and intervention for financial hardship and psychological problems to help manage depression.

Trends and patterns of North Korea's disease burden from 1990 to 2019: Results from Global Burden of Disease study 2019.

BACKGROUND: Evidence for the trends and patterns of disease burden in North Korea is limited, and in-depth analysis based on several health outcomes for a better understanding remains challenging. Therefore, we aimed to investigate the trends and patterns of disease burden in North Korea between 1990 and 2019. METHODS: We used data from the Global Burden of Diseases (GBD) 2019 study to analyze the North Korean disease burden in comparison with four groups: global, South Korea, low-sociodemographic index (SDI) countries, Central and Eastern Europe, and Central Asia (former socialist countries). We also examined changes in the disease burden between 1990 and 2019 by disease category and age group. FINDINGS: In 2019, in North Korea, death rates and disability-adjusted life years (DALYs) rates were reduced by 22.2% and 30.7%, respectively, compared to 1990. The rates showed similar trends and patterns to that in former socialist countries. However, these reductions were lower than those of the global rates and rates in low-SDI countries and South Korea. Death rates and DALY rates for under five years dramatically decreased by more than 78%, similar to the trend in South Korea. In contrast, the decline in the death rates and DALY rates of adults was less than those worldwide and in low-SDI countries and South Korea. The burden of diseases among those aged ≥30 years increased largely due to the persistently high burden of non-communicable diseases (NCDs). Cardiovascular diseases, neoplasms, and chronic respiratory diseases were the leading causes of the disease burden in both 1990 and 2019. INTERPRETATION: North Korea's disease burden patterns and trends show clear improvements over the past 30 years but suggest that the current challenges of NCDs in the country are very serious. NCDs should be no longer neglected and should be prioritized in public health agendas in North Korea.