ABSTRACT
Polymer-wrapped single-walled carbon nanotubes (SWNTs) are a potential method for obtaining high-purity semiconducting (sc) SWNT solutions. Conjugated polymers (CPs) can selectively sort sc-SWNTs with different chiralities, and the structure of the polymer side chains influences this sorting capability. While extensive research has been conducted on modifying the physical, optical, and electrical properties of CPs through side-chain modifications, the impact of these modifications on the sorting efficiency of sc-SWNTs remains underexplored. This study investigates the introduction of various conjugated side chains into naphthalene diimide-based CPs to create a biaxially extended conjugation pattern. The CP with a branched conjugated side chain (P3) exhibits reduced aggregation, resulting in improved wrapping ability and the formation of larger bundles of high-purity sc-SWNTs. Grazing incidence X-ray diffraction analysis confirms that the potential interaction between sc-SWNTs and CPs occurs through π-π stacking. The field-effect transistor device fabricated with P3/sc-SWNTs demonstrates exceptional performance, with a significantly enhanced hole mobility of 4.72 cm2 V-1 s-1 and high endurance/bias stability. These findings suggest that biaxially extended side-chain modification is a promising strategy for improving the sorting efficiency and performance of sc-SWNTs by using CPs. This achievement can facilitate the development of more efficient and stable electronic devices.
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The development of lithium-ion batteries (LIBs) is important in the realm of energy storage. Understanding the intricate effects of binders on the Li+ transport at the cathode/electrolyte interface in LIBs remains a challenge. This study utilized molecular dynamics simulations to compare the molecular effects of conventional polyvinylidene difluoride (PVDF), Li+-coordinating polyethylene oxide (PEO), and negatively charged polystyrene sulfonate (PSS) binders on local Li+ mobility at the electrolyte/LiFePO4 (LFP) cathode interface. By examining concentration profiles of Li+, three different polymer binders, and anions near Li+-rich LFP and Li+-depleted FePO4 (FP) surfaces, we found a superior performance of the negatively charged PSS on enhancing Li+ distribution near the Li+-depleted FP surface. The radial distribution function and coordination number analyses revealed the potent interactions of PEO and PSS with Li+ disrupting Li+ coordination with electrolyte solvents. Our simulations also revealed the effects of non-uniform binder dispersions on the Li+ local mobility near the cathode surface. The combined results provide a comparative insight into Li+ transport at the electrolyte/cathode interface influenced by distinct binder chemistries, offering a profound understanding of the binder designs for high-performance LIBs.
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This work uses density functional theory (DFT) calculations and kinetic Monte Carlo (kMC) simulations to compare the diffusion of S-vacancies on defective MoS2 and WS2, two structures that are often discussed as catalysts. Similar to what has been discussed for MoS2, the vacancy diffusion barriers on WS2 also follow Brønsted-Evans-Polanyi (BEP) type linear scaling relations. The vacancy diffusion kinetics is discussed at the example of a large vacancy cluster consisting of 37 unoccupied sites in direct vicinity and how its structure changes with time. Using barriers estimated via linear scaling relations as input for the kMC simulations yields results that qualitatively agree with results calculated self-consistently at DFT level. As the diffusion barriers for WS2 are significantly higher than those for MoS2, the vacancy diffusion on WS2 is poorly described by the linear scaling relations derived from MoS2 and vice versa. This work further shows that one needs DFT level barriers of about 40% of all S-vacancy diffusion processes on a material to derive sufficiently reliable linear scaling relations. This means that computational costs for future studies may be reduced by only explicitly computing one fraction of the diffusion barriers while estimating the remaining ones via linear scaling. However, in this case, one would lack information about the partition function of the transition states, which are needed for calculating the rate constants. Thus, we have also proposed a scheme to estimate the contribution of the partition functions based only on the initial state's vibrational modes.
ABSTRACT
BACKGROUND: To prevent school injuries, thorough epidemiological data is an essential foundation. We aimed to investigate the characteristics of school injuries in Asia and explore risk factors for major trauma. METHODS: This retrospective study was conducted in the participating centers of the Pan-Asian Trauma Outcome Study from October 2015 to December 2020. Subjects who reported "school" as the site of injury were included. Major trauma was defined as an Injury Severity Score (ISS) value of ≥16. RESULTS: In total, 1305 injury cases (1.0% of 127,715 events) occurred at schools. Among these, 68.2% were children. Unintentional injuries were the leading cause and intentional injuries comprised 7.5% of the cohort. Major trauma accounted for 7.1% of those with documented ISS values. Multivariable regression revealed associations between major trauma and factors, including age, intention of injury (self-harm), type of injury (traffic injuries, falls), and body part injured (head, thorax, and abdomen). Twenty-two (1.7%) died, with six deaths related to self-harm. Females represented 28.4% of injuries but accounted for 40.9% of all deaths. CONCLUSIONS: In Asia, injuries at schools affect a significant number of children. Although the incidence of injuries was higher in males, self-inflicted injuries and mortality cases were relatively higher in females. IMPACT: Epidemiological data and risk factors for major trauma resulting from school injuries in Asia are lacking. This study identified significant risk factors for major trauma occurring at schools, including age, intention of injury (self-harm), injury type (traffic injuries, falls), and body part injured (head, thoracic, and abdominal injuries). Although the incidence of injuries was higher in males, the incidence of self-harm injuries and mortality rates were higher in females. The results of this would make a significant contribution to the development of prevention strategies and relative policies concerning school injuries.
Subject(s)
Accidents, Traffic , Wounds and Injuries , Child , Male , Female , Humans , Retrospective Studies , Accidents, Traffic/prevention & control , Injury Severity Score , Asia/epidemiology , Schools , Wounds and Injuries/epidemiologyABSTRACT
Correction for 'First-principles modeling of the highly dynamical surface structure of a MoS2 catalyst with S-vacancies' by Po-Yuan Wang et al., Phys. Chem. Chem. Phys., 2022, 24, 24166-24172, https://doi.org/10.1039/D2CP03384D.
ABSTRACT
Children and adolescents are vulnerable to non-accidental injury. Early identification and prevention rely on detailed epidemiological studies, which are limited in Asia. This retrospective study used the registry data of Pan-Asian Trauma Outcome Study (PATOS) from October 1, 2015 to December, 31, 2020. Pediatric patients (aged < 20 years) with non-accidental injuries were enrolled, which were divided by age into preschool (0-6 years), child (7-12 years), and adolescent (13-19 years) groups. Baseline characteristics, injury epidemiology, and excess mortality ratio-adjusted injury severity score (EMR-ISS) were collected. Major trauma was defined as an EMR-ISS score > 24. The study enrolled 451 patients with non-accidental injuries, accounting for 2.81% of pediatric trauma events presented to an emergency department in the PATOS registry. The overall mortality rate was 0.9%, similar to those in Western countries. Mortality rate was high in preschool children (8.7%, p = 0.017) than in other age groups. The sex-specific incidence was higher in boys (3.10% vs. 2.13%, p = 0.001). In adolescents, more events occurred on the street (25.9%), whereas home remained the most common locale in girls of all ages. In the multivariable regression analysis, abdominal and multiple injuries were risk factors for major trauma.
Subject(s)
Multiple Trauma , Wounds and Injuries , Male , Female , Humans , Child , Child, Preschool , Adolescent , Infant , Retrospective Studies , Asia , Emergency Service, Hospital , Injury Severity Score , Wounds and Injuries/epidemiologyABSTRACT
A new copper indium selenide, Ba3.5Cu7.55In1.15Se9, was synthesized by the KBr flux reaction at 800 °C. The compound crystallizes with orthorhombic Pnma, a = 46.1700(12) Å, b = 4.26710(10) Å, c = 19.8125(5) Å, and Z = 8. The structural framework mainly consists of four sites of cubane-type defective M4Se3 (M = Cu, Cu/In) units with disordered Cu+/In3+ ions present at the part corner of each unit. The single crystal emits intense photoluminescence at 657 nm with a relative quantum yield (RQY) 0.2 times that of rhodamine 6G powder. The compound belongs to a direct band gap at 1.91 eV, analyzed by Tauc's plot, and the energy is close to the PL position. The Hall effect measurement on a pressed pellet reveals an n-type conductivity with a carrier concentration of 3.358 × 1017 cm-3 and a mobility of 24.331 cm2 V-1 s-1. Furthermore, the compound produces a strong nonlinear third-harmonic generation (THG), with an χS(3) value of 1.3 × 105 pm2/V2 comparable to 1.6 × 105 pm2/V2 for AgGaSe2 measured at 800 nm.
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BACKGROUND: Bronchiolitis is a common airway infection in young children. Hemodynamically significant congenital heart disease (CHD) predicts a more complicated course. However, the role of airway anomalies remains unknown. METHODS: We retrospectively reviewed the records of patients under 2 years old, diagnosed with CHD, and admitted between January 2011 and December 2013, before the palivizumab era. Records of bronchiolitis admissions were also extracted. Patients were grouped according to CHD condition and airway anomalies. RESULTS: A total of 230 patients with CHD were enrolled. A total of 180 (78%) and 71 (31%) patients had hemodynamically significant CHD and airway anomalies, respectively. A total of 52 (22.6%) patients were admitted for bronchiolitis 78 times. Among them, 33 (63.5%) had hemodynamically significant CHD, and 28 (53.8%) had airway anomalies. In patients with bronchiolitis admissions, the mean ventilator use, intensive care unit stay, and hospital stay were 1.08, 4.08, and 15.19 days, respectively. When compared, the mean hospital stay for bronchiolitis patients with airway anomalies was significantly longer than that of those without airway anomalies (19.8 vs. 9.9 days, p = 0.008). When further divided the patients by the presence hemodynamic significance, patients with hemodynamically significant CHD and airway anomaly had longer hospital stay than those who had neither. (21.7 vs. 8.3 days, p = 0.004) Airway anomaly was a significant risk factor for longer hospital stay in linear regression model (p = 0.007). CONCLUSIONS: Airway anomalies are common in children with CHD and are associated with longer hospital stays on bronchiolitis admission. An active survey for airway anomalies and adequate prophylaxis for bronchiolitis infection might be important in the care of children with CHD associated with airway anomalies.
Subject(s)
Bronchiolitis , Heart Defects, Congenital , Respiratory Syncytial Virus Infections , Humans , Child , Infant , Child, Preschool , Respiratory Syncytial Virus Infections/drug therapy , Retrospective Studies , Bronchiolitis/complications , Bronchiolitis/epidemiology , Bronchiolitis/drug therapy , Palivizumab/therapeutic use , Hospitalization , Heart Defects, Congenital/complications , Heart Defects, Congenital/epidemiology , Length of StayABSTRACT
Vacancy sites, e.g., S-vacancies, are essential for the performance of MoS2 catalysts. As earlier studies have revealed that the size and shape of the S-vacancies may affect the catalytic activity, we have studied the behavior and mobility of such vacancies on MoS2 using DFT calculations and kinetic Monte-Carlo (kMC) simulations. The diffusion barriers for the S-vacancies are highly dependent on the immediate environment: isolated single S-vacancies are found to be immobile. In contrast, small nS-vacancies formed from n = 2 to 5 neighboring S-vacancies are often highly dynamic systems that can move within a confined area. Large extended nS-vacancies are generally unstable and transform quickly into alternating patterns of S-atoms and vacancy sites. These results illustrate the importance of recognizing MoS2 (but also other catalysts) as dynamic structures when trying to tune their catalytic performances by introducing specific defect structures.
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Background: Few studies have investigated the epidemiology of cardiomyopathy (CMP) in the general population in Taiwan. The aim of this study was to investigate this issue. Methods: We identified patients aged < 65 years and diagnosed with CMP between 2001 and 2014 from the National Health Insurance Database of Taiwan 2000-2014. Those with known or presumed causes of CMP were further identified. Results: We identified 38,868 CMP patients (male/female = 2.13). Half had known or presumed causes of CMP, including coronary artery disease (23.6%), congenital heart disease (1.6%), metabolic disease (8.4%), conduction disturbance/dyssynchrony (2.2%), myocarditis (0.5%), muscular dystrophy (1.42%), Kawasaki disease (0.2%), nutrition problems or alcoholism (2.9%), and unspecified causes (12.4%). The incidence rates of CMP without known causes were 1.13 and 8.70 per 100,000 person-years in pediatric (0-19 years) and adult (20-64 years) populations, respectively. After an initial peak during infancy (9.16 per 100,000 person-years), the incidence declined to a nadir in those aged from 5 to 14 years, and then steadily increased during adulthood (26.51 per 100,000 person-years in those aged 60-64 years). Although mortality was higher in the pediatric (11.4%) than in the adult (1.5%) patients, the proportion of sudden death to all deaths was similar in the pediatric (9.9%) and adult (10.5%) patients. Conclusions: This study provides an epidemiological continuum of CMP in a Taiwanese population aged < 65 years. The results revealed an initial peak during infancy, followed by a decline in adolescence and a subsequent steady rise. The prognosis was poorer in the pediatric patients, and poorest in the infants. However, the risk of sudden death was the same in the adult and pediatric patients.
Subject(s)
Brain Diseases , COVID-19 , Child , Humans , SARS-CoV-2 , COVID-19/complications , Brain Diseases/etiology , BrainABSTRACT
Background: Dilated cardiomyopathy (DCM) is the most common childhood cardiomyopathy. The epidemiological profiles and prognosticators of clinical outcomes in Asian populations are not well elucidated. Methods: Data of 104 children aged <18 years with a diagnosis of primary DCM from January 1990 to December 2019 in our institutional database were retrospectively investigated. Relevant demographic, echocardiographic, and clinical variables were recorded for analysis. A P <0.05 was considered statistically significant. Results: The median age at diagnosis was 1.4 years (interquartile range = 0.3-9.1 years), and 52.9% were males. During a median follow-up duration of 4.8 years, 48 patients (46.2%) were placed on the transplantation waitlist, and 52.1% of them eventually received heart transplants. An exceptionally high overall waitlist mortality rate was noted (27.1%), which was even higher (43.5%) if the diagnostic age was <3 years. The 1-, 5-, and 10-year transplant-free were 61.1, 48.0, and 42.8%. Age at diagnosis >3 years and severe mitral regurgitation at initial diagnosis were independent risk factors for death or transplantation (hazard ratios = 2.93 and 3.31, respectively; for both, P <0.001). In total, 11 patients (10.6%) experienced ventricular function recovery after a median follow-up of 2.5 (interquartile range = 1.65-5) years. Younger age at diagnosis was associated a higher probability of ventricular function recovery. Conclusions: Despite donor shortage for heart transplantation and subsequently high waitlist mortality, our data from an Asian cohort indicated that transplant-free long-term survival was comparable with that noted in reports from Western populations. Although younger patients had exceptionally higher waitlist mortality, lower diagnostic age was associated with better long-term survival and higher likelihood of ventricular function recovery.
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Penrose's pentagonal P2 quasi-crystal1-4 is a beautiful, hierarchically organized multiscale structure in which kite- and dart-shaped tiles are arranged into local motifs, such as pentagonal stars, which are in turn arranged into various close-packed superstructural patterns that become increasingly complex at larger length scales. Although certain types of quasi-periodic structure have been observed in hard and soft matter, such structures are difficult to engineer, especially over large areas, because generating the necessary, highly specific interactions between constituent building blocks is challenging. Previously reported soft-matter quasi-crystals of dendrimers5, triblock copolymers6, nanoparticles7 and polymeric micelles8 have been limited to 12- or 18-fold symmetries. Because routes for self-assembling complex colloidal building blocks9-11 into low-defect dynamic superstructures remain limited12, alternative methods, such as using optical and directed assembly, are being explored13,14. Holographic laser tweezers15 and optical standing waves16 have been used to hold microspheres in local quasi-crystalline arrangements, and magnetic microspheres of two different sizes have been assembled into local five-fold-symmetric quasi-crystalline arrangements in two dimensions17. But a Penrose quasi-crystal of mobile colloidal tiles has hitherto not been fabricated over large areas. Here we report such a quasi-crystal in two dimensions, created using a highly parallelizable method of lithographic printing and subsequent release of pre-assembled kite- and dart-shaped tiles into a solution-dispersion containing a depletion agent. After release, the positions and orientations of the tiles within the quasi-crystal can fluctuate, and these tiles undergo random, Brownian motion in the monolayer owing to frequent collisions between neighbouring tiles, even after the system reaches equilibrium. Using optical microscopy, we study both the equilibrium fluctuations of the system at high tile densities and also the 'melting' of the pattern as the tile density is lowered. At high tile densities we find signatures of a five-fold pentatic liquid quasi-crystalline phase, analogous to a six-fold hexatic liquid crystal. Our fabrication approach is applicable to tiles of different sizes and shapes, and with different initial positions and orientations, enabling the creation of two-dimensional quasi-crystalline systems (and other systems that possess multiscale complexity at high tile densities) beyond those of current self- or directed-assembly methods18-20. We anticipate that our approach for generating lithographically pre-assembled monolayers could be extended to create three-dimensional Brownian systems of fluctuating particles with custom-designed shapes through holographic lithography21,22 or stereolithography23.
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Bronchopulmonary dysplasia (BPD), a disease affecting extremely premature infants, results from the disruption of normal pulmonary vascular and alveolar growth. Currently, there is no specific effective treatment. We report a case of a 10-mo-old female infant with BPD, who was admitted because of adenovirus pneumonia and acute respiratory distress syndrome (ARDS) with prolonged venovenous and arteriovenous extracorporeal membrane oxygenation (ECMO) support (total 125 d). The respiratory condition dramatically improved, and ECMO was removed 25 d after intratracheal delivery of maternal bone marrow-derived mesenchymal stem cells (BM-MSCs). Short tandem repeat examinations revealed that there was no maternal cells in the bronchial wash fluid. To our knowledge, this is the first human report of BM-MSC therapy reversal of the course of BPD superimposed with ARDS. We also suggest that BM-MSC therapy may not only be effective in the newborn stage but also works in infants and children with BPD.
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Proteins can self-assemble into a variety of exquisitely organized structures through hierarchical reaction pathways. To examine how different core shapes of proteins and entropy combine to influence self-assembly, we create systems of lithographically fabricated proteomimetic colloids, or 'proteoids', and explore how Brownian monolayers of mobile proteoids, which have hard interactions, self-assemble as they are slowly crowded. Remarkably, chiral C-shaped proteoids having circular heads on only one side form enantiopure lock-and-key chiral dimers; these dimers have corrugated, shape-complementary perimeters, so they, in turn, form lock-and-key arrangements into chiral dimer crystals. Time-lapse video microscopy reveals the expulsion of monomers from the growing dimer crystals through tautomerization translocation reactions which expedite the crystallization kinetics. By lithographically mutating proteoids, we also tune the types and structures of the resulting dimer crystals. Thus, rational design of sub-particle features in hard-core colloidal shapes can be used to sterically select desired self-assembly pathways without introducing any site-specific attractions, thereby generating a striking degree of hierarchical self-ordering, reminiscent of protein crystallization.
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Colloidal annular sectors are a broad class of shapes that offer the interesting possibility of dimerization when osmotically compressed to high densities while undergoing Brownian motion in two dimensions (2D). Here, we lithographically create and form a stable aqueous dispersion of many microscale prismatic 270° annular sectors, and we explore their near-equilibrium behavior in a tilted 2D gravitational column. Near the top of the column where the 2D gravitational osmotic pressure Π(2D) is low, we observe a gas-like phase composed almost entirely of monomers. However, below the surface and deeper into the column where Π(2D) is higher, we observe a reaction zone where monomers and dimers coexist, followed by an arrested region containing a very high percentage of interpenetrating, lock-and-key dimers that are a racemic mixture of positive and negative chiralities. We determine particle area fractions of monomers and dimers as a function of depth and use these to obtain the system's 2D osmotic equation of state. In the reaction zone, where dimers transiently form and break up, we also use these to calculate the equilibrium constant K associated with the monomer-dimer reaction, which increases exponentially with Π(2D). This dependence can be attributed the reduction in number of accessible microstates for dimers as they become more tightly compressed.