Search

Patients with mood disorders commonly manifest comorbid psychiatric disorders, including attention-deficit/hyperactivity disorder (ADHD). However, few studies have evaluated ADHD symptoms in this population. The current study aimed to explore the network structure of ADHD symptomology and identify central symptoms in patients with mood disorders. The Korean version of the Adult ADHD Self-Report Scale was used to assess the overall ADHD symptoms in 1,086 individuals diagnosed with mood disorders (major depressive disorder [n = 373], bipolar I disorder [n = 314], and bipolar II disorder [n = 399]). We used exploratory graph analysis to detect the number of communities, and the network structure was analyzed using regularized partial correlation models. We identified the central ADHD symptom using centrality indices. Network comparison tests were conducted with different subgroups of patients with mood disorders, including three mood diagnosis groups, between the patients who met the diagnostic criteria for ADHD [ADHD-suspected, n = 259] in their self-report and the others [ADHD-non-suspected, n = 827], and groups with high [n = 503] versus low [n = 252] levels of depressive state. The network analysis detected four communities: disorganization, agitation/restlessness, hyperactivity/impulsivity, and inattention. The centrality indices indicated that "feeling restless" was the core ADHD symptom. The result was replicated in the subgroup analyses within our clinically diverse population of mood disorders, encompassing three presentations: Patients with suspected ADHD, patients without suspected ADHD, and patients with a high depressive state. Our findings reveal that "feeling restless" is the central ADHD symptom. The treatment intervention for "feeling restless" may thus play a pivotal role in tackling ADHD symptoms in adult patients with mood disorders. [ABSTRACT FROM AUTHOR]

Star-shaped poly(l-lactide) (starPLLA) and poly(d-lactide) (starPDLA) were synthesized, and their terminal groups were capped with cinnamate functionalities to obtain cinnamate-terminated star-shaped polylactides (C-starPLLA and C-starPDLA). It was confirmed that both starPLLA and C-starPLLA showed better solubility in various organic solvents than their corresponding linear polylactides. Polymer films of C-starPLLA and its blends with C-starPDLA (C-starPLLA/PDLA) were effectively crosslinked by UV irradiation. The molecular weights of the films were found to become higher when the irradiation was done after annealing the films, suggesting that the increased polymer crystallization by the annealing ought to promote the concentration of the cinnamate functionalities in the amorphous domain, inducing the subsequent terminal photo-crosslinking more efficiently. Furthermore, the aqueous emulsions of C-nPLAs and C-starPLAs were successfully prepared and used for fabrication of their films by emulsion casting. When the resultant polymer films were annealed and UV-irradiated, the film was found to become much harder due to the higher degree of crosslinking. These results supported that the star-shaped structure with photo-crosslinkable terminals should be an effective approach to provide PLAs having improved processability and properties simultaneously. Star-shaped poly(L-lactide) (starPLLA) and poly(D-lactide) (starPDLA) were synthesized, and their terminal groups were capped with cinnamate functionalities to obtain cinnamate-terminated star-shaped polylactides (C-starPLLA and C-starPDLA). It was confirmed that both starPLLA and C-starPLLA showed better solubility in various organic solvents than their corresponding linear polylactides. Polymer films of C-starPLLA and its blend with C-starPDLA (C-starPLLA/PDLA) were effectively crosslinked by UV irradiation. These results supported that the star-shaped structure with photo-crosslinkable terminals should be an effective approach to provide PLAs having improved processability and properties simultaneously. [ABSTRACT FROM AUTHOR]

High-molecular-weight ABA triblock copolymers (PLA–PEs–PLA), consisting of poly-l-lactide (PLLA: A) and two types of polyethers (PEs: B), i.e., poly(oxyethylene) (PEG: polyethylene glycol) and Pluronic® [PN: poly(oxyethylene)-b-poly(oxypropylene)-b-poly(oxyethylene)], were synthesized by ring-opening polymerization of l-lactide by using bis-hydroxyl-terminated PEs as macroinitiators. Polymer films of these block copolymers were fabricated by the conventional hot-pressing method and uniaxially cold drawn to five times at 80 °C. Evaluation of the mechanical properties of these films revealed that the drawn films can retain high strength (ca. 100 MPa) and improved flexibility (2 GPa in modulus). It was therefore evident that the drawn films of PLLA–PEs triblock copolymers are highly useful as flexible films that can be controlled by the PEs content. The A–B–A triblock copolymers consisting of PLLA and polyethers (PE: PEG and PN) were synthesized by the ROP of l-lactide in the presence of telechelic PE as the macroinitiators. The drawn films of these block copolymers were found to compete with the conventional petroleum plastic films and exceed the current biobased and biodegradable polymer films in terms of toughness. Thus, the oriented copolymer films were shown to be highly useful for flexible PLLA-based films. [ABSTRACT FROM AUTHOR]

Childhood trauma and interpersonal sensitivity impact the development of mood disorders. In this study, we investigate the association between childhood trauma and interpersonal sensitivity in patients with mood disorders. A total 775 patients (major depressive disorder [MDD, n = 241], bipolar I disorder [BD I, n = 119], and bipolar II disorder [BD II, n = 415]) and 734 controls. For evaluation, we used the Childhood Trauma Questionnaire-Short Form (CTQ) and Interpersonal Sensitivity Measure (IPSM). We examined between-group differences for each subscale in the CTQ and IPSM. Patients with BD II had significantly higher IPSM total scores than patients with MDD, BD I, or controls. The CTQ total score was related to the IPSM total score in all participants and subgroups. Among the CTQ subscales, emotional abuse showed the highest correlation with the IPSM total score, while separation anxiety and fragile inner self showed higher positive correlations with CTQ than the other subscales of IPSM in all patient groups and the control group, respectively. The findings reveal that childhood trauma and interpersonal sensitivity are positively correlated among patients with MDD, BD I, and BD II, and that interpersonal sensitivity is higher in patients with BD II than those with BD I or MDD. Childhood trauma is associated with interpersonal sensitivity, and each trauma type has a different impact on mood disorders. We expect that this study will encourage future research on interpersonal sensitivity and childhood trauma in mood disorders to improve treatment approaches. [ABSTRACT FROM AUTHOR]

Carbon capture and utilization technology has been studied for its practical ability to reduce CO2 emissions and enable economical chemical production. The main challenge of this technology is that a large amount of thermal energy must be provided to supply high-purity CO2 and purify the product. Herein, we propose a new concept called reaction swing absorption, which produces synthesis gas (syngas) with net-zero CO2 emission through direct electrochemical CO2 reduction in a newly proposed amine solution, triethylamine. Experimental investigations show high CO2 absorption rates (>84%) of triethylamine from low CO2 concentrated flue gas. In addition, the CO Faradaic efficiency in a triethylamine supplied membrane electrode assembly electrolyzer is approximately 30% (@−200 mA cm−2), twice higher than those in conventional alkanolamine solvents. Based on the experimental results and rigorous process modeling, we reveal that reaction swing absorption produces high pressure syngas at a reasonable cost with negligible CO2 emissions. This system provides a fundamental solution for the CO2 crossover and low system stability of electrochemical CO2 reduction. Carbon capture, utilization and storage technology is limited by the need for a separate CO2 capture step. Here, the authors propose a strategy and economic analysis for simultaneous dilute CO2 capture from flue gas and direct electrochemical reduction to synthesis gas via reaction swing absorption. [ABSTRACT FROM AUTHOR]

Electrochemical conversion of abundant resources, such as carbon dioxide, water, nitrogen, and nitrate, is a remarkable strategy for replacing fossil fuel-based processes and achieving a sustainable energy future. Designing an efficient and selective electrocatalysis system for electrochemical conversion reactions remains a challenge due to a lack of understanding of the reaction mechanism. Shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) is a promising strategy for experimentally unraveling a reaction pathway and rate-limiting step by detecting intermediate species and catalytically active sites that occur during the reaction regardless of substrate. In this review, we introduce the SHINERS principle and its historical developments. Furthermore, we discuss recent SHINERS applications and developments for investigating intermediate species involved in a variety of electrocatalytic reactions. [ABSTRACT FROM AUTHOR]

Stabilizing the best-performing state-of-the-art perovskite solar cells (PSCs) based on a spiro-OMeTAD hole transport material (HTM), without sacrificing their high power conversion efficiency (PCE) levels, is a challenging task. By exploiting the symmetry-tuned strategy at the molecular level, we have developed spiro-OMeTAD analogues (namely, the spiro-Naph series) with asymmetric phenylnaphthylamine edge units. The new spiro-Naph HTM-based PSC achieved a high PCE of 24.43%, higher than that achieved with spiro-OMeTAD. In addition to excellent stability when soaking the encapsulated device with continuous light, superior device stability was also obtained for the unencapsulated spiro-Naph-based PSC—a PCE of 21.12% was retained in air with ~25% relative humidity after 2,000 h and a PCE of 18.79% was retained at an elevated temperature of 60 °C after 400 h. We also constructed a spiro-Naph-based large-area module (25 cm2) with a PCE of 21.83%. The use of a new hole transport material called spiro-Naph allows the realization of efficient large-area perovskite solar cells. [ABSTRACT FROM AUTHOR]

Fast oxygen-ion conductors for use as electrolyte materials have been sought for energy conversion and storage. Bi2O3-based ionic conductors that exhibit the highest known oxygen-ion conductivities have received attention for use in next-generation solid electrolytes. However, at intermediate temperatures below ~600 °C, their conductivities degrade rapidly owing to a cubic-to-rhombohedral phase transformation. Here, we demonstrate that physical manipulation of the grain structure can be used to preserve the superior ionic conductivity of Bi2O3. To investigate the effects of microstructural control on stability, epitaxial and nanopolycrystalline model films of Er0.25Bi0.75O1.5 were fabricated by pulsed laser deposition. Interestingly, in situ impedance and ex situ XRD analyses showed that the grain boundary-free epitaxial film significantly improved the stability of the cubic phase, while severe degradation was observed in the conductivity of its polycrystalline counterpart. Consistently, the cation interdiffusion coefficient measured by the Boltzmann–Matano method was much lower for the epitaxial thin film compared to the polycrystalline thin film. Furthermore, first-principles calculations revealed that the presence of grain boundaries triggered the structural resemblance between cubic and rhombohedral phases, as evidenced by radial distribution functions. Additionally, phase transition energetics predicted that the thermodynamic stability of the cubic phase with respect to the rhombohedral counterpart is reduced near grain boundaries. Thus, these findings provide novel insights into the development of highly durable superionic conductors via microstructural engineering.We, for the first time, reveal that manipulation of microstructure enables the suppression of phase transformation and enhancement of long-term stability of Bi2O3-based ionic conductors. To investigate the microstructural influence on the stability, thin films with precisely defined grain structures are prepared. The conductivity of polycrystalline thin film decreased by 94.6% after approximately 20 h of operation, while the initial conductivity of epitaxial thin film remained almost constant during annealing for up to 100 h. This study provides novel insights for the development of highly conductive and durable solid electrolytes for next-generation energy applications. [ABSTRACT FROM AUTHOR]

The single process CO2 capture-mineralization approach integrates methods of CO2 absorption using aqueous solvents and mineral carbonation technology to not only remove carbon dioxide quickly, but also to simultaneously produce precipitated calcium carbonate (PCC). To develop a more sustainable process, it is important to extract calcium from inexpensive raw materials such as industrial by-products. The extractant has a significant effect on the quality of the calcium carbonate produced because it determines the anion paired with the calcium cation. In this work, several calcium sources with different anions (Propionate, Acetate, Nitrate and Chloride) were applied in the single process CO2 capture-mineralization method, and their influence on the polymorph of the obtained CaCO3 was investigated. The CaCO3 produced with inorganic calcium sources predominantly exhibited a calcite structure, while the CaCO3 produced with organic calcium sources had a structure in which vaterite and calcite coexist. This result was in good agreement with our DFT calculations, which indicated the adsorption energy of the organic anions (Propionate and Acetate) were lower than the inorganic anions on the surface of vaterite. Except for chloride with its non-polar nature, in most cases, there was a strong correlation between the polymorph and the adsorption energy calculated for each surface. A mechanism for the polymorph CaCO3 formation in our single process CO2 capture-mineralization method was proposed after observing crystal formation at low concentration. [ABSTRACT FROM AUTHOR]

Electrochemical processes coupling carbon dioxide reduction reactions with organic oxidation reactions are promising techniques for producing clean chemicals and utilizing renewable energy. However, assessments of the economics of the coupling technology remain questionable due to diverse product combinations and significant process design variability. Here, we report a technoeconomic analysis of electrochemical carbon dioxide reduction reaction–organic oxidation reaction coproduction via conceptual process design and thereby propose potential economic combinations. We first develop a fully automated process synthesis framework to guide process simulations, which are then employed to predict the levelized costs of chemicals. We then identify the global sensitivity of current density, Faraday efficiency, and overpotential across 295 electrochemical coproduction processes to both understand and predict the levelized costs of chemicals at various technology levels. The analysis highlights the promise that coupling the carbon dioxide reduction reaction with the value-added organic oxidation reaction can secure significant economic feasibility. Coupling of carbon dioxide reduction and organic oxidation is promising for sustainable chemicals production; however, economics are impacted by variations in product combinations and process design. Here the authors report technoeconomic analysis for a range of technologies and coproduction processes. [ABSTRACT FROM AUTHOR]

Chilsan Island Group, located on the west coast of South Korea, has been recognized as a critical breeding and nursery ground for endangered seabirds because food is abundant and human activity is low. Chilsan Island Group has been under protection as a Natural Monument (Article no. 389) since 1997, but attempts were made in 2004 to exploit the coastal sands around the islands. A conceptual ecological model (CEM) was employed with energy flow diagram (EFD) to predict the effects of sand mining on the islands’ ecosystem. The results showed that sand mining activities caused long-term damage to benthic ecosystems and threatened seabird communities by reducing fish populations throughout the food web. The changes in energy flow in the ecosystem due to sand mining operations predict that reduction in secondary production of benthic animal communities might reduce energy transfer to humans and seabirds by 30%. Different ranges of uncertainty provided by the Monte Carlo simulation lead to the conclusion that sand mining could bring about undesirable consequences. One concern is that such negative consequences would have a much more severe impact on seabirds than humans because seabirds cannot compete effectively against humans for the limited food sources. In this study, the complex interrelationships between ecosystem members were simplified and a CEM was established to clearly identify which elements would be affected. The CEM with EFD was found to be helpful in promoting communication between stakeholders, and it is expected to be widely used as a decisionmaking tool by public officials. [ABSTRACT FROM AUTHOR]

Sodium (Na)-ion batteries (NIBs) have attracted significant interest as an alternative chemistry to lithium (Li)-ion batteries for large-scale stationary energy storage systems. Discovering high-performance anode materials is a great challenge for the commercial success of NIB technology. Transition metal oxides with tailored nanoarchitectures have been considered as promising anodes for NIBs due to their high capacity. Here, we demonstrate the fabrication of a nanostructured oxide-only electrode, i.e., carbon- and binder-free NiCoO nanoneedle array (NCO-NNA), and its feasibility as an anode for NIBs. Furthermore, we provide an in-depth experimental study of the Na storage reaction (sodiation and desodiation) in NCO-NNA. The NCO-NNA electrode is fabricated on a conducting substrate by a hydrothermal method with subsequent heat treatment. When tested in an electrochemical Na half-cell, the NCO-NNA electrode exhibits excellent Na storage capability: a charge capacity as high as 400 mAh g is achieved at a current density of 50 mA g. It also shows a greatly improved cycle life (~215 mAh g after 50 cycles) in comparison to a conventional powder-type electrode (~30 mAh g). However, the Na storage performance is still inferior to that of Li, which is mainly due to sluggish kinetics of sodiation-desodiation accompanied by severe volume change. [ABSTRACT FROM AUTHOR]

This paper proposes an analytical approach that can describe the Pulsed Eddy Current Testing (PECT) of stratified conductive structures by a single air-coil used for detecting and sizing of metal loss due to interlayer corrosion. Specifically for a single air-cored coil above a multilayered conductive structure, the coil impendance response of the cylindrical eddy-current probe is calculated based on the truncated region eigenfunction expansion (TREE) method using the generalized matrix coefficients in series form. Analytical modeling of pulsed eddy current is developed using the Fourier series for multilayered conductive structures. A simulation study is carried out for demonstrating the capability of the proposed approach for sizing the metal loss in a two-layer specimen. Furthermore, the experiment is set up to confirm the simulating results of the analytical model for multilayered steels. Good agreement between the theoretical results and measured signals is observed. [ABSTRACT FROM AUTHOR]

The fluoroelastomer rubber (FR) was successfully incorporated in natural rubber (NR) matrix composites using a colloid stabilization-destabilization methodology in the spherical shape of a few-micrometer size, where the electrostatic surface charge of the FR and NR colloidal drops were controlled to give either stable or unstable colloid mixtures. Measuring the zeta potential of the drops with respect to pH, the stabilized colloid mixture ensured the FR to be incorporated up to 25 phr in the NR matrix as a well-dispersed ocean-island composite structure with the FR size of 0.5∼10 μm. The NR/FR composites including various additive fillers showed a good interfacial bonding and enhanced thermal stability with substantially increased mechanical properties of strength as well as elongation- at-break values. This novel technique provided a unique and highly loaded composite structure composed of FR spherical particles well dispersed in the NR matrix, which can hardly be achieved by the conventional shear-mixing techniques because of the high viscosity and viscoelastic characteristics of elastomers. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Amentoflavone is a well-known biflavonoid that has diverse biological effects. Previously, we reported that amentoflavone suppressed UVB-induced matrix metalloproteinase-1 (MMP-1) expression in normal human fibroblasts (NHF). We investigated the effects of amentoflavone on UVB-induced MMP-1 expression in order to elucidate its mode of action. NHF were treated with amentoflavone for indicated times and doses with UVB irradiation. The expressions of MMP-1 gene and protein were determined by RT-PCR and ELISA, respectively. MAP kinase phosphorylation and the expression of c-Fos protein were determined by Western blot. The treatment of amentoflavone completely blocked the upregulation of MMP-1 which is induced by UVB irradiation in HaCaT-NHF co-culture in a dose-dependent manner as well as in NHF monoculture. Also, amentoflavone inhibited UVB-induced activation of extracellular signal-regulated kinase (ERK) without changing total ERK protein level, and did not affect p38 or JNK activation. Finally, AP-1 transcription factor components, phospho-c-Jun and c-Fos protein expressions were decreased by amentoflavone treatment. The major finding of this study shows that amentoflavone inhibits intracellular cell signaling ERK pathway leading to the prevention of MMP-1 expression in human skin fibroblasts. Therefore, these results strongly suggest that amentoflavone should be investigated as a potential agent for the prevention and the treatment of skin photoaging. [ABSTRACT FROM AUTHOR]

Photochemical reactions of N-trimethylsilylmethyl-substituted uracil, pyridone and pyrrolidone derivatives were carried out to determine if silicone containing substituents have an impact on excited state reaction profiles. The results show that ultraviolet irradiation of N-trimethylsilylmethyl substituted uracils in the presence of substituted alkenes leads to efficient formation of both dimeric and cross [2+2]-cycloaddition products. Qualitatively similar observations were made in a study of the photochemistry of N-trimethylsilylmethyl-2-pyridone. The combined results demonstrate that [2+2]-photocycloaddition is a more efficient excited state reaction pathway for the uracil and pyridone substrates as compared to other processes, such as ylide-forming trimethylsilyl group C-to-O migration. Finally, photoreactions of N-trimethylsilylmethyl-2-pyrrolidone in solutions containing dipolarophiles, such as methyl acrylate, lead to the formation of the desilylation product, N-methyl-2-pyrrolidone by way of a simple, non-ylide generating, protodesilylation process. In addition, observations were made which show that orbital symmetry allowed photocycloreversion reactions of dimeric uracil derivatives, involving cyclobutane ring splitting, to take place. These processes, which lead to the formation of monomeric uracils, appear to be stimulated by the presence of electron donor groups on the cyclobutane ring, a likely result of a new SET promoted cyclobutane ring cleavage pathway. In the cases of N-trimethylsilylmethyl-substituted cyclobutane derivatives that possess phthalimide groups, highly efficient excited state cleavage of the cyclobutane moiety occurs to produce uracil derivatives and corresponding vinyl phthalimide. [ABSTRACT FROM AUTHOR]

Pd metal and Pd-based alloys are ideal catalysts that allow for the electrochemical conversion of CO2 to HCOO− at almost zero-overpotential with high selectivity, but catalyst degradation caused by concurrent CO poisoning limits their practical implementation. Here, we demonstrate that cyclic two-step electrolysis, by applying the reduction and oxidation potentials alternately, achieves 100% current density stability and 97.8% selectivity toward HCOO− production for at least 45 h. The key idea for achieving the reliability is based on the selective removal of CO by controlling the parameters during the oxidation step, which utilizes the different reversibility of HCOO− and CO production reactions. Furthermore, it is found that potentiostatic electrolysis causes CO adsorption and subsequent dehydridation, which in turn lowers HCOO− selectivity. Our work provides a system-level strategy for solving the poisoning issue that is inevitable in many electrocatalytic reactions. Reduction of carbon dioxide is promising for the production of value-added chemicals, but electrocatalysts are hindered by carbon monoxide poisoning. Here, the authors alternate reduction and oxidation potentials to achieve stable and selective long-term electrocatalytic reduction of carbon dioxide to formate. [ABSTRACT FROM AUTHOR]

Electrochemical conversion of CO2 and water to valuable chemicals and fuels is one of the promising alternatives to replace fossil fuel-based processes in realizing a carbon-neutral cycle. For practical application of such technologies, suppressing hydrogen evolution reaction and facilitating the activation of stable CO2 molecules still remain major challenges. Furthermore, high production selectivity toward high-value chemicals such as ethylene, ethanol, and even n-propanol is also not easy task to achieve. To settle these challenges, deeper understanding on underlying basis of reactions such as how intermediate binding affinities can be engineered at catalyst surfaces need to be discussed. In this review, we briefly outline recent strategies to modulate the binding energies of key intermediates for CO2 reduction reactions, based on theoretical insights from density functional theory calculation studies. In addition, important design principles of catalysts and electrolytes are also provided, which would contribute to the development of highly active catalysts for CO2 electroreduction. [ABSTRACT FROM AUTHOR]

Stereo multi-block polylactides (multi-sb-PLA) having controlled block sequences of poly(L-lactide) (PLLA) and poly(D-lactide) (PDLA) were synthesized by chain-extension of stereo tri-block polylacitdes (PLLA-PDLA-PLLA) that were readily synthesized by two-step ring-opening polymerization (ROP) of D- and L-lactides. The weight-average molecular weight of the resultant multi-sb-PLAs reached about 14.3 × 104 Da. These multi-sb-PLAs were found to exclusively form stereocomplex (sc) crystals without homo-chiral (hc) crystallization occurring because the quickly formed sc crystals effectively suppressed the hc crystallization as cross-linkers. Their thermal properties could be tuned by controlling the block lengths of PLLA-PDLA-PLLA in the two-step ROP. Particularly, the multi-sb-PLAs consisting of longer PLLA and PDLA blocks in 1:1 ratio exhibited higher sc crystallinity and thermo-mechanical properties after thermal annealing. [ABSTRACT FROM AUTHOR]

The oxygen evolution reaction (OER) is considered a major bottleneck in the overall water electrolysis process. In this work, highly active manganese oxide nano-catalysts were synthesized via hot injection. Facile surface treatment generated Mn(III) species on monodisperse 10 nm MnO nanocrystals (NCs). Size dependency of MnO NCs on OER activity was also investigated. Surprisingly, the partially oxidized MnO NCs only required 530 mV @ 5 mA cm−2 under near neutral conditions. [ABSTRACT FROM AUTHOR]