Fast Polysulfide Conversion Catalysis and Reversible Anode Operation by A Single Cathode Modifier in Li-Metal Anode-Free Lithium-Sulfur Batteries.

The two major issues confronting the commercialization of rechargeable lithium-sulfur (Li-S) batteries are the sluggish kinetics of the sulfur electrochemical reactions on the cathode and inadequate lithium deposition/stripping reversibility on the anode. They are commonly mitigated with additives designed specifically for the anode and the cathode individually. Here, we report the use of a single cathode modifier, In2 Se3 , which can effectively catalyse the polysulfide reactions on the cathode, and also improve the reversibility of Li deposition and removal on the anode through a LiInS2 /LiInSe2 containing solid electrolyte interface formed in situ by the Se and In ions dissolved in the electrolyte. The amounts of dissolved Se and In are small relative to the amount of In2 Se3 administered. The benefits of using this single modification approach were verified in Li-metal anode-free Li-S batteries with a Li2 S loading of 4 mg cm-2 and a low electrolyte/Li2 S ratio of 7.5 µL mg-1 . The resulting battery showed 60 % capacity retention after 160 cycles at the 0.2 C rate and an average Coulombic efficiency of 98.27 %, comparing very well with recent studies using separate electrode modifiers.

The effect of air purifiers and curtains on aerosol dispersion and removal in multi-patient hospital rooms.

Airborne transmission of disease is of concern in many indoor spaces. Here, aerosol dispersion and removal in an unoccupied 4-bed hospital room were characterized using a transient aerosol tracer experiment for 38 experiments covering 4 configurations of air purifiers and 3 configurations of curtains. NaCl particle (mass mean aerodynamic diameter ~3 µm) concentrations were measured around the room following an aerosol release. Particle transport across the room was 1.5-4 min which overlaps with the characteristic times for significant viral deactivation and gravitational settling of larger particles. Concentrations were close to spatially uniform except very near the source. Curtains resulted in a modest increase in delay and decay times, less so when combined with purifiers. The aerosol decay rate was in most cases higher than expected from the clean air delivery rate, but the reduction in steady-state concentrations resulting from air purifiers was less than suggested by the decay rates. Apparently, a substantial (and configuration-dependent) fraction of the aerosol is removed immediately, and this effect is not captured by the decay rate. Overall, the combination of curtains and purifiers is likely to reduce disease transmission in multi-patient hospital rooms.

Translational Applications of Wearable Sensors in Education: Implementation and Efficacy.

BACKGROUND: Adding new approaches to teaching curriculums can be both expensive and complex to learn. The aim of this research was to gain insight into students' literacy and confidence in learning sports science with new wearable technologies, specifically a novel program known as STEMfit. METHODS: A three-phase design was carried out, with 36 students participating and exposed to wearable devices and associated software. This was to determine whether the technology hardware (phase one) and associated software (phase two) were used in a positive way that demonstrated user confidence. RESULTS: Hardware included choosing a scalable wearable device that worked in conjunction with familiar and readily available software (Microsoft Excel) that extracted data through VBA coding. This allowed for students to experience and provide survey feedback on the usability and confidence gained when interacting with the STEMfit program. Outcomes indicated strong acceptance of the program, with high levels of motivation, resulting in a positive uptake of wearable technology as a teaching tool by students. The initial finding of this study offers an opportunity to further test the STEMfit program on other student cohorts as well as testing the scalability of the system into other year groups at the university level.

Reopening businesses after Hurricane Harvey: evidence from a duration model with spatial effects.

Post-disaster business return is key to restoring the local economy. This paper applies a duration model to analyse factors that explain the delay in reopening a business in south Texas, United States, after Hurricane Harvey struck the region in August 2017. Other than property damage, the duration of business closure depended on the type of business and the various characteristics of its owner. Reflecting the vital role that social capital plays in disaster resilience, local chamber of commerce members tended to reopen their businesses sooner than their non-member counterparts. Yet, there is evidence in support of the vulnerability of female chamber members. In addition to social networks, the finding of spatial interdependence implies that the decision of business owners to resume operations in the wake of a disaster is influenced by the decisions of their neighbours. Spatial interdependence also highlights the importance of providing disaster relief to businesses in a timely manner.

An Effective Design of Electrically Conducting Thin-Film Composite (TFC) Membranes for Bio and Organic Fouling Control in Forward Osmosis (FO).

The organic foulants and bacteria in secondary wastewater treatment can seriously impair the membrane performance in a water treatment plant. The embedded electrode approach using an externally applied potential to repel organic foulants and inhibit bacterial adhesion can effectively reduce the frequency of membrane replacement. Electrode embedment in membranes is often carried out by dispensing a conductor (e.g., carbon nanotubes, or CNTs) in the membrane substrate, which gives rise to two problems: the leaching-out of the conductor and a percolation-limited membrane conductivity that results in an added energy cost. This study presents a facile method for the embedment of a continuous electrode in thin-film composite (TFC) forward osmosis (FO) membranes. Specifically, a conducting porous carbon paper is used as the understructure for the formation of a membrane substrate by the classical phase inversion process. The carbon paper and the membrane substrate polymer form an interpenetrating structure with good stability and low electrical resistance (only about 1Ω/□). The membrane-electrode assembly was deployed as the cathode of an electrochemical cell, and showed good resistance to organic and microbial fouling with the imposition of a 2.0 V DC voltage. The carbon paper-based FO TFC membranes also possess good mechanical stability for practical use.

Introducing amphiphilicity to noble metal nanoclusters via phase-transfer driven ion-pairing reaction.

Amphiphilicity is a surface property that has yet to be explored for the noble metal nanoclusters (NCs). This article shows how amphiphilicity may be added to sub-2-nm metal NCs by patching hydrophilic NCs (e.g., Au25(MHA)18 NCs where MHA is 6-mercaptohexanoic acid) with hydrophobic cations (e.g., cetyltrimethylammonium ion, CTA(+)) to about half of a monolayer coverage. Specifically we demonstrate the preparation of amphiphilic Au25(MHA)18@xCTA NCs (x = 6-9 where x is the number of CTA(+) per NC) by the phase-transfer (PT) driven ion-paring reaction between CTA(+) and -COO(-) (derived from the deprotonation of the terminal carboxyl group of MHA). Due to the coexistence of flexible hydrophilic MHA and hydrophobic MHA···CTA ligands in comparable amounts on the NC surface, the Au25(MHA)18@xCTA NCs (x = 6-9) exhibit good amphiphilicity, which enabled them to dissolve in solvents with distinctly different polarities and to self-assemble like a molecular amphiphile. Consequently, the amphiphilic Au25(MHA)18@xCTA NCs (x = 6-9) could self-organize into stacked bilayers at the air-liquid interface, similar to the formation of lyotropic liquid crystalline phases by common surfactants. The good solubility and molecular-amphiphile-like self-assembly properties can significantly increase the utility of noble metal NCs in basic and applied research.

Architectural design of heterogeneous metallic nanocrystals--principles and processes.

CONSPECTUS: Heterogeneous metal nanocrystals (HMNCs) are a natural extension of simple metal nanocrystals (NCs), but as a research topic, they have been much less explored until recently. HMNCs are formed by integrating metal NCs of different compositions into a common entity, similar to the way atoms are bonded to form molecules. HMNCs can be built to exhibit an unprecedented architectural diversity and complexity by programming the arrangement of the NC building blocks ("unit NCs"). The architectural engineering of HMNCs involves the design and fabrication of the architecture-determining elements (ADEs), i.e., unit NCs with precise control of shape and size, and their relative positions in the design. Similar to molecular engineering, where structural diversity is used to create more property variations for application explorations, the architectural engineering of HMNCs can similarly increase the utility of metal NCs by offering a suite of properties to support multifunctionality in applications. The architectural engineering of HMNCs calls for processes and operations that can execute the design. Some enabling technologies already exist in the form of classical micro- and macroscale fabrication techniques, such as masking and etching. These processes, when used singly or in combination, are fully capable of fabricating nanoscopic objects. What is needed is a detailed understanding of the engineering control of ADEs and the translation of these principles into actual processes. For simplicity of execution, these processes should be integrated into a common reaction system and yet retain independence of control. The key to architectural diversity is therefore the independent controllability of each ADE in the design blueprint. The right chemical tools must be applied under the right circumstances in order to achieve the desired outcome. In this Account, after a short illustration of the infinite possibility of combining different ADEs to create HMNC design variations, we introduce the fabrication processes for each ADE, which enable shape, size, and location control of the unit NCs in a particular HMNC design. The principles of these processes are discussed and illustrated with examples. We then discuss how these processes may be integrated into a common reaction system while retaining the independence of individual processes. The principles for the independent control of each ADE are discussed in detail to lay the foundation for the selection of the chemical reaction system and its operating space.

Counterion-assisted shaping of nanocluster supracrystals.

Ag44 (p-MBA)30 (4-) (p-MBA=para-mercaptobenzoic acid) nanocluster (NC) supracrystals (SCs) with customizable shapes can be obtained by simply altering the type and concentration of the counterions of the p-MBA ligands in the dimethylsulfoxide (DMSO)/water crystallization system. Changing the counterion of the p-MBA ligand from H(+) to Cs(+) eliminates the directional hydrogen bonds in the SCs, resulting in the packing of deprotonated Ag44 (p-MBA)30 (4-) NCs into octahedral SCs, which is in stark contrast to the rhombohedral SCs that were formed by the packing of protonated Ag44 (p-MBA)30 (4-) NCs in previous studies. Furthermore, the double layer of deprotonated Ag44 (p-MBA)30 (4-) NCs is sensitive to charge screening induced by increasing the Cs(+) concentration, thereby providing a means to regulate the precipitation kinetics of the Ag44 (p-MBA)30 (4-) NCs for SC shape engineering. Slow precipitation kinetics was found to favor over-growth at the corners and edges of the octahedral SC nuclei, shaping the SCs into concave octahedra.

Phosphorous-Based Heterostructure for the Effective Catalysis of Polysulfide Reactions with Phase Changes in High-Sulfur-Loading Lithium-Sulfur Batteries.

High sulfur loading and long cycle life are the design targets of commercializable lithium-sulfur (Li-S) batteries. The sulfur electrochemical reactions from Li2 S4 to Li2 S, which account for 75% of the battery's theoretical capacity, involve liquid-to-solid and solid-to-solid phase changes in all Li-S battery electrolytes in use today. These are kinetically hindered processes that are exacerbated by a high sulfur loading. In this study, it is observed that an in situ grown bimetallic phosphide/black phosphorus (NiCoP/BP) heterostructure can effectively catalyze the Li2 S4 to Li2 S reactions to increase the sulfur utilization at high sulfur loadings. The NiCoP/BP heterostructure is a good polysulfide adsorber, and the electric field prevailing at the Mott-Schottky junction of the heterostructure can facilitate charge transfer in the Li2 S4 to Li2 S2 liquid-to-solid reaction and Li+ diffusion in the Li2 S2 to Li2 S solid-state reaction. Consequently, a sulfur cathode with the NiCoP/BP catalyst can deliver a specific capacity of 830 mAh g-1 at the sulfur loading of 6 mg cm-2 for 500 cycles at the 0.5 C rate. High sulfur utilization is also possible at a higher sulfur loading of 8 mg cm-2 for 440 cycles at the 1 C rate.

Sociodemographic and geographic disparities in COVID-19 booster vaccination in Nueces County, Texas, USA.

Objective: This paper explores sociodemographic determinants and geographic disparities in COVID-19 booster uptake among fully vaccinated adults in Nueces County, Texas, USA with a population of over 353,000. Methods: A logistic generalized additive model was applied to analyze 184,252 official vaccination records of fully vaccinated adults over the period between December 2020 and August 2022. An individual's odds in receiving a booster shot were estimated with a host of sociodemographic characteristics as predictors. Results: Model estimation results reveal that male (odds ratio 0.836, 95% confidence interval 0.835-0.836, p < 0.001) and Hispanic residents (odds ratio 0.944, 95% confidence interval 0.943-0.945, p < 0.001) in the county were less likely to take a booster shot. Between the ages of 25 and 75, booster uptake increased with age (age 75 vs. 45 odd ratio 3.058, 95% confidence interval 3.052-3.063, p < 0.001). Booster uptake was lower in rural areas (odds ratio 0.804, 95% confidence interval 0.795-0.814, p < 0.001) and communities with high social vulnerability (highest vs. moderate vulnerability odd ratio 0.800, 95% confidence interval 0.767-0.836, p < 0.001). Conclusion: Empirical results confirm that booster uptake varied across individuals and communities of different socioeconomic and demographic characteristics. To advance health equity, a more inclusive vaccine campaign should pay particular attention to those underserved populations.

Graphene-like MoS2/graphene composites: cationic surfactant-assisted hydrothermal synthesis and electrochemical reversible storage of lithium.

A cationic surfactant-assisted hydrothermal route is developed for the facile synthesis of graphene-like MoS2 /graphene (GL-MoS2 /G) composites based on the hydrothermal reduction of Na2 MoO4 and graphene oxide sheets with L-cysteine in the presence of cetyltrimethylammonium bromide (CTAB), following by annealling in N2 atmosphere. The GL-MoS2 /G composites are characterized by X-ray diffraction, electron microscopy, high-resolution transmission electron microscopy, and Raman spectroscopy. The effects of CTAB concentration on the microstructures and electrochemical performances of the composites for reversible Li(+) storage are investigated. It is found that the layer number of MoS2 sheets decreases with increasing CTAB concentration. The GL-MoS2 sheets in the composites are few-layer in the case of 0.01∼0.03 mol L(-1) CTAB of hydrothermal solution and single-layer in the case of 0.05 mol L(-1) CTAB. The GL-MoS2 /G composites prepared with 0.01-0.02 mol·L(-1) of CTAB solution exhibit a higher reversible capacity of 940-1020 mAh g(-1) , a greater cycle stability, and a higher rate capability than other samples. The exceptional electrochemical performance of GL-MoS2 /G composites for reversible Li(+) storage could be attributed to an effective integration of GL-MoS2 sheets and graphene that maximizes the synergistic interaction between them.

Imiquimod-induced TLR7 signaling enhances repair of DNA damage induced by ultraviolet light in bone marrow-derived cells.

Imiquimod is a TLR7/8 agonist that has anticancer therapeutic efficacy in the treatment of precancerous skin lesions and certain nonmelanoma skin cancers. To test our hypothesis that imiquimod enhances DNA repair as a mechanism for its anticancer activity, the nucleotide excision repair genes were studied in bone marrow-derived cells. Imiquimod enhanced the expression of xeroderma pigmentosum (XP) A and other DNA repair genes (quantitative real-time PCR analysis) and resulted in an increased nuclear localization of the DNA repair enzyme XPA. This was dependent on MyD88, as bone marrow-derived cells from MyD88(-/-) mice did not increase XPA gene expression and did not enhance the survival of MyD88(-/-)-derived bone marrow-derived cells after UV B exposure as was observed in bone marrow-derived cells from MyD88(+/+) mice. Imiquimod also enhanced DNA repair of UV light (UVL)-irradiated gene expression constructs and accelerated the resolution of cyclobutane pyrimidine dimers after UVL exposures in P388 and XS52. Lastly, topical treatment of mouse skin with 5% imiquimod cream prior to UVL irradiation resulted in a decrease in the number of cyclobutane pyridimine dimer-positive APC that were found in local lymph nodes 24 h after UVL irradiation in both wild-type and IL-12 gene-targeted mice. In total, these data support the idea that TLR7 agonists such as imiquimod enhance DNA repair in bone marrow-derived cells. This property is likely to be an important mechanism for its anticancer effects because it protects cutaneous APC from the deleterious effects of UVL.

Self-Decoupled Oxygen Electrocatalysis for Ultrastable Rechargeable Zn-Air Batteries with Mild-Acidic Electrolyte.

Rechargeable zinc-air batteries (ZABs) have been considered promising as next-generation sustainable energy storage devices; however, their large-scale deployment is hampered by the unsatisfactory cyclic lifespan. Employing neutral and mild-acidic electrolytes is effective in extending the cyclability, but the rapid performance degradation of the bifunctional catalysts owing to different microenvironmental requirements of the alternative oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is still a serious limitation of their cyclic life. Herein, we propose a "self-decoupling" strategy to significantly improve the stability of the bifunctional catalysts by constructing a smart interface in the bifunctional air electrode. This smart interface, containing a resistance-switchable sulfonic acid doped polyaniline nanoarray interlayer, is nonconductive at high potential but conductive at low potential, which enables spontaneous electrochemical decoupling of the bifunctional catalyst for the ORR and OER, respectively, and thus protects it from degradation. The resulting self-decoupled mild-acidic ZAB delivers stable cyclic performances in terms of a negligible energy efficiency loss of 0.015% cycle-1 and 3 times longer cycle life (∼1400 h) compared with the conventional mild-acidic ZAB using a normal bifunctional air electrode and the same low-cost ZnCo phosphide/nitrogen-doped carbon bifunctional catalyst. This work provides an effective strategy for tolerating alternative oxidation-reduction reactions and emphasizes the importance of smart nanostructure design for more sustainable batteries.

Dynamic-self-catalysis as an accelerated air-cathode for rechargeable near-neutral Zn-air batteries with ultrahigh energy efficiency.

Neutral/near-neutral electrolyte rechargeable zinc-air batteries (NN-ZABs) with long cycling lifetime are an evolutionary design of the conventional alkaline ZABs, but the extremely sluggish kinetics of oxygen electrocatalysis in mild pH solutions in the air-cathode has notably affected the energy efficiency of the NN-ZABs. Herein, we present a dynamic self-catalysis as the air-cathode chemistry to boost the energy efficiency of NN-ZABs, which is based on in situ reversible generation of highly active electrocatalysts from the electrolyte during the discharge and charge operations of ZABs, respectively. Two reversible redox reactions of Cu(I)/Cu(II) and Mn(II)/Mn(IV) in the NH4Cl-ZnCl2-based electrolyte are integrated with oxygen electrocatalysis in the air-cathode to in situ generate Cu(I)-O-Cl deposits during discharging and Cu-MnO2 deposits during charging, which directly catalyze the subsequent oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), respectively. The in situ generated electrocatalysts deliver good oxygen electrocatalytic activities due to their distinctive surface structures and can be dissolved by potential reversal in a subsequent battery operation. The NN-ZAB designed as such delivers a record-high energy efficiency of 69.0% and a cycling life of 1800 h with an areal capacity of 10 mA h cm-2, surpassing the performances of NN-ZABs with preloaded electrocatalysts reported to date.

Association of HLA-A, B, and C alleles and cancer susceptibility in 179 solid malignancies.

BACKGROUND: The major histocompatibility complex (MHC) genes are known to be capable of influencing the susceptibility of many cancers. All mammalian cells, including cancer cells, express MHC class I molecules consisting of human leukocyte antigens (HLA) A, B, and C. The tumor susceptibility of HLA-A, B, and C alleles has not been studied extensively in solid tumors. METHODS: HLA-A, B, and C genotypes of 179 solid tumors were collected from Caris Comprehensive Tumor Profiling reports, including 45 GU, 44 GI, 28 pancreaticobiliary, 21 thoracic, 15 breast, 13 Gyn, among others. The tumors were mainly from Caucasians (82%). The HLA allele frequencies in the tumors were compared to those of respective ethnic populations in the US National Marrow Donor Program (NMDP) database. Fisher's exact tests were performed, adjusted P values were calculated using Benjamini-Hochberg's method for false discovery rate (FDR), and Prevalence ratios (PRs) were calculated to quantify associations. RESULTS: Twenty-one alleles were not listed in the NMDP. Among them, A*11:303 alone was present in 11 carcinomas, and B*08:222 was seen in 4 tumors. Among the alleles listed in the NMDP, C*08:02, B*14:02, A*03:02, and B*44:06 were significantly associated with tumors in Caucasian Americans (PR: 2.50-170), while B*44:02 appeared protective (PR: 0.36). Alleles with less significant associations were listed. CONCLUSIONS: From the HLA-A, B, and C data of the 179 tumors, we identified several susceptible alleles and one protective allele. Of interest, 21 alleles were not listed in the NMDP. The limited cases prevented our analysis from identifying cancer-susceptible alleles in other races.

Hollow and cage-bell structured nanomaterials of noble metals.

Mastery of the structure of nanomaterials enables control of their properties to enhance their performance for a given application. Herein we demonstrate the synthesis of metal nanomaterials with hollow interiors or cage-bell structures based on the inside-out diffusion of Ag in core-shell structured nanoparticles. It begins with the synthesis of core-shell Ag-M or core-shell-shell M(A)-Ag-M(B) nanoparticles in an organic solvent. Ag is then extracted from the core or the inner shell by bis(p-sulfonatophenyl)phenylphosphane, which binds strongly with Ag(I)/Ag(0) to allow the complete removal of Ag in 24-48 h, leaving behind an organosol of hollow or cage-bell structured metal nanomaterials. Because of their relatively lower densities, which usually translate to a higher surface area than their solid counterparts, the hollow and cage-bell structured metal nanomaterials are especially relevant to catalysis. For example, cage-bell structured Pt-Ru nanoparticles were found to display outstanding methanol tolerance for the cathode reaction of direct methanol fuel cells (DMFCs) as a result of the differential diffusion of methanol and oxygen in the cage-bell structure.

From aggregation-induced emission of Au(I)-thiolate complexes to ultrabright Au(0)@Au(I)-thiolate core-shell nanoclusters.

A fundamental understanding of the luminescence of Au-thiolate nanoclusters (NCs), such as the origin of emission and the size effect in luminescence, is pivotal to the development of efficient synthesis routes for highly luminescent Au NCs. This paper reports an interesting finding of Au(I)-thiolate complexes: strong luminescence emission by the mechanism of aggregation-induced emission (AIE). The AIE property of the complexes was then used to develop a simple one-pot synthesis of highly luminescent Au-thiolate NCs with a quantum yield of ~15%. Our key strategy was to induce the controlled aggregation of Au(I)-thiolate complexes on in situ generated Au(0) cores to form Au(0)@Au(I)-thiolate core-shell NCs where strong luminescence was generated by the AIE of Au(I)-thiolate complexes on the NC surface. We were able to extend the synthetic strategy to other thiolate ligands with added functionalities (in the form of custom-designed peptides). The discovery (e.g., identifying the source of emission and the size effect in luminescence) and the synthesis protocols in this study can contribute significantly to better understanding of these new luminescence probes and the development of new synthetic routes.

Phase transfer and its applications in nanotechnology.

As nanoparticle syntheses in aqueous and organic systems have their own merits and drawbacks, specific applications may call for the transfer of newly formed nanoparticles from a polar to a non-polar environment (or vice versa) after synthesis. This critical review focuses on the application of phase transfer in nanoparticle synthesis, and features core-shell structures in bimetallic nanoparticles, replacement reactions in organic media, and catalytic properties of various nanostructures. It also describes the reversible organic and aqueous phase transfer of semiconductor and metallic nanoparticles for biological applications, and the use of phase transfer in depositing noble metals on semiconductor nanoparticles (258 references).

COVID-19 Vaccine Hesitancy: The Role of Socioeconomic Factors and Spatial Effects.

This paper investigates the spatial dimension of socioeconomic and demographic factors behind COVID-19 vaccine hesitancy. With a focus on a county with considerable sociodemographic diversity in the state of Texas, USA, we apply regression models to census-tract-level data of the unvaccinated population. In addition to disparities in accessing the vaccination service, particularly for residents in rural areas, empirical results confirm under-vaccination among lower socioeconomic neighborhoods and communities with signs of distrust in government. The spatial model regressions further underscore the impact that vaccine hesitancy among residents in one community spread to its nearby communities. This observed spatial spillover effect is attributable to the geographic interactions of similar socioeconomic groups.

Performance stability among small and medium-sized enterprises during COVID-19: A test of the efficacy of dynamic capabilities.

COVID-19 wreaked havoc on public health and the global economy. Small and medium-sized enterprises (SMEs) were hit especially hard. In this research note, we test the ability of dynamic capabilities (DCs) to predict SME performance during the pandemic. Based on our analysis of data from a survey conducted in the United States, we find that DCs meaningfully predicted both operational levels and revenue. Furthermore, while the empirical literature suggests that SME size is positively related to DC efficacy, we found that this effect was reversed during COVID-19, as the positive link between DCs and performance was stronger for smaller SMEs.