Tailored Graphene Micropatterns by Wafer-Scale Direct Transfer for Flexible Chemical Sensor Platform

2D materials, such as graphene, exhibit great potential as functional materials for numerous novel applications due to their excellent properties. The grafting of conventional micropatterning techniques on new types of electronic devices is required to fully utilize the unique nature of graphene. However, the conventional lithography and polymer-supported transfer methods often induce the contamination and damage of the graphene surface due to polymer residues and harsh wet-transfer conditions. Herein, a novel strategy to obtain micropatterned graphene on polymer substrates using a direct curing process is demonstrated. Employing this method, entirely flexible, transparent, well-defined self-activated graphene sensor arrays, capable of gas discrimination without external heating, are fabricated on 4 in. wafer-scale substrates. Finite element method simulations show the potential of this patterning technique to maximize the performance of the sensor devices when the active channels of the 2D material are suspended and nanoscaled. This study contributes considerably to the development of flexible functional electronic devices based on 2D materials.

Enhanced Oxygen Evolution Electrocatalysis in Strained A-Site Cation Deficient LaNiO3 Perovskite Thin Films

As the BO₆ octahedral structure in perovskite oxide is strongly linked with electronic behavior, it is actively studied for various fields such as metal-insulator transition, superconductivity, and so on. However, the research about the relationship between water-splitting activity and BO₆ structure is largely lacking. Here, we report the oxygen evolution reaction (OER) of LaNiO₃ (LNO) by changing the NiO₆ structure using compositional change and strain. The 5 atom % La deficiency in LNO resulted in an increase of the Ni-O-Ni bond angle and an expansion of bandwidth, enhancing the charge transfer ability. In-plane compressive strain derives the higher d_z² orbital occupancy, leading to suitable metal-oxygen bond strength for OER. Because of the synergistic effect of A-site deficiency and compressive strain, the overpotential (η) of compressively strained L_0.95NO film is reduced to 130 mV at j = 30 μA/cm² compared with nonstrained LNO (η = 280 mV), indicating a significant enhancement in OER.

Association between minimum inhibitory concentration, beta-lactamase genes and mortality for patients treated with piperacillin/tazobactam or meropenem from the MERINO study

INTRODUCTION

This study aims to assess the association of piperacillin/tazobactam and meropenem minimum inhibitory concentration (MIC) and beta-lactam resistance genes with mortality in the MERINO trial.

METHODS

Blood culture isolates from enrolled patients were tested by broth microdilution and whole genome sequencing at a central laboratory. Multivariate logistic regression was performed to account for confounders. Absolute risk increase for 30-day mortality between treatment groups was calculated for the primary analysis (PA) and the microbiologic assessable (MA) populations.

RESULTS

320 isolates from 379 enrolled patients were available with susceptibility to piperacillin/tazobactam 94% and meropenem 100%. The piperacillin/tazobactam non-susceptible breakpoint (MIC > 16 mg/L) best predicted 30-day mortality after accounting for confounders (odds ratio 14.9, 95% CI 2.8 - 87.2). The absolute risk increase for 30-day mortality for patients treated with piperacillin/tazobactam compared with meropenem was 9% (95% CI 3% - 15%) and 8% (95% CI 2% - 15%) for the original PA population and the post-hoc MA populations, which reduced to 5% (95% CI -1% - 10%) after excluding strains with piperacillin/tazobactam MIC values > 16 mg/L. Isolates co-harboring ESBL and OXA-1 genes were associated with elevated piperacillin/tazobactam MICs and the highest risk increase in 30-mortality of 14% (95% CI 2% - 28%).

CONCLUSION

After excluding non-susceptible strains, the 30-day mortality difference was from the MERINO trial was less pronounced for piperacillin/tazobactam. Poor reliability in susceptibility testing performance for piperacillin/tazobactam and the high prevalence of OXA co-harboring ESBLs suggests meropenem remains the preferred choice for definitive treatment of ceftriaxone non-susceptible E. coli and Klebsiella.

A multicentre comparative study between laparoscopic and open surgery for intussusception in adults

AIM

Intussusception in adults is rare and requires surgery in most cases. While abdominal laparoscopic surgery (LS) is becoming more popular, there are few reports on the outcomes of adult intussusception treated with LS. This study compared the feasibility of LS vs open surgery (OS) for adult intussusception.

METHOD

We reviewed retrospectively the medical records of adult patients with intussusception from three tertiary hospitals between 2000 and 2016. The patients were divided into LS and OS groups, and their surgical outcomes were compared.

RESULTS

Surgery was indicated in 71 patients with intussusception (41 LS and 30 OS). The median age of the patients was 49.0 and 51.5 years in the LS and OS groups, respectively (P = 0.930). Overall, nine (12.7%) patients had a negative laparotomy or laparoscopy with spontaneous reduction of the intussusception. Conversion to OS from LS was necessary in one patient (2.4%). The operative time and intra-operative and postoperative complication rates were not significantly different. However, there were more serious complications such as bowel perforation and major vessel injury in the LS group. The patients in the LS group had a shorter time to first food intake and hospital stay vs patients in the OS group (4.0 vs 6.0 days, P < 0.001, and 7.0 vs 10.5 days, P < 0.001, respectively).

CONCLUSION

LS may be feasible for adult intussusception; there may be more severe intra-operative complications than in OS.

Electrochemical activity of Samarium on starch-derived porous carbon: rechargeable Li- and Al-ion batteries

Rechargeable metal-ion batteries are considered promising electric storage systems to meet the emerging demand from electric vehicles, electronics, and electric grids. Thus far, secondary Li-ion batteries (LIBs) have seen great advances in terms of both their energy and their power density. However, safety issues remain a challenge. Therefore, rechargeable Al-ion batteries (AIBs) with a highly reliable safety advantage and active electrochemical performances have gathered intensive attention. However, the common issue for these two metal-ion batteries is the lack of cathode materials. Many advanced electrode materials reported provide greatly enhanced electrochemical properties. However, their inherent disadvantages-such as complicated fabrication procedures, restricted manufacturing parameters, and the requirement of expensive instruments-limits their potential for further applications. In this work, we demonstrate the high electrochemical activity of the lanthanide element, Sm, towards storing charges when used in both LIBs and AIBs. Lanthanide elements are often overlooked; however, they generally have attractive electrochemical properties owing to their unpaired electrons. We employed starch as both a low-cost carbon source and as a three-dimensional support for Sm metal nanoparticles. The composite product is fabricated using a one-pot wet-chemical method, followed by a simultaneous carbonization process. As a result, highly improved electrochemical properties are obtained when it is used as a cathode material for both LIBs and AIBs when compared to bare starch-derived C. Our results may introduce a new avenue toward the design of high-performance electrode materials for LIBs and AIBs.

Boosting Aerobic Oxidation of Alcohols via Synergistic Effect between TEMPO and a Composite Fe3O4/Cu-BDC/GO Nanocatalyst

Fabrication of a nanocomposite catalyst via a novel and efficient strategy remains a challenge; Fe₃O₄ nanoparticles anchored on graphene oxide (GO) sheet-supported metal-organic frameworks (MOFs). In this study, the physicochemical properties of the ensuing Fe₃O₄/Cu-BDC/GO are investigated using Fourier transform infrared spectrum, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, energy-dispersive X-ray detector, and atomic absorption spectroscopy. The salient features of the nanocomposite such as Cu-MOF, synergistic effect with GO sheets, and magnetic separation characteristics make it an excellent ternary heterostructure for aerobic oxidation of alcohols. The proposed nanocatalyst and co-catalyst 2,2,6,6-tetramethylpiperidine-N-oxyl substantially enhance the catalytic performance for the aerobic oxidation under very mild and sustainable reaction conditions. The heterogeneity of Fe₃O₄/Cu-BDC/GO composite catalyst is affirmed with the added advantage that the initial activity is well maintained even after seven cycles.

Rendering Redox Reactions of Cathodes in Li-Ion Capacitors Enabled by Lanthanides

Capacitors allow extremely fast charge and discharge operations, which is a challenge faced by recent metal-ion batteries despite having highly improved energy densities. Thus, combined type electric energy storage devices that can integrate high energy density and high power density with high potentials, can overcome the shortcomings of the current metal-ion batteries and capacitors. However, the limited capacities of cathode materials owing to the barren redox reactions are regarded as an obstacle for the development of future high-performance hybrid metal-ion capacitors. In this study, we demonstrate the redox-reaction-rendering effect of the much overlooked lanthanide elements when used as the cathode of lithium-ion capacitors using the mesoporous carbon (MC) as a matrix material. Consequently, these lanthanide elements can effectively enrich the redox reaction, thus improving the capacity of the matrix materials by more than two times. Typically, the Gd-elemental decoration of MC surprisingly enhances the capacity by almost two times as compared with the underacted MC. Furthermore, the La nanoparticles (NPs) decoration depicts the same behavior. Evident redox peaks were formed on the original rectangular cyclic voltammetry (CV) curves. This study provides the first example of embedding lanthanide elements on matrix materials to enrich the desired redox reactions for improving the electrochemical performances.

Cerium Hexacyanocobaltate: A Lanthanide-Compliant Prussian Blue Analogue for Li-Ion Storage

Electrode materials are the most significant components of lithium-ion batteries (LIBs) and play an important role in endowing them with high electrochemical performance. The exploration of new electrode materials and their comparative study with contemporary resources will help the design of advanced electrodes. Here, we have synthesized a new type of Prussian blue analogue (cerium(III) hexacyanocobaltate, CeHCCo) and systematically explored the effect of valence states of Fe2+ and Ce3+ on crystal structure and electrochemical properties of final products. We demonstrate that the unbalanced charge in iron(II) hexacyanocobaltate (FeHCCo), as opposed to that in CeHCCo, results in more residual K+ ions, thereby leading to the occupancy of cavities. As a result, the K+ ion-rich FeHCCo exhibits lower capacities of 55 ± 3 and 15 ± 3 mAh g-1 at 0.1 and 1 A g-1, respectively, compared with the K+ ion-deficient CeHCCo that exhibits capacities of 242 ± 3 and 111 ± 3 mAh g-1 at the same current densities. This work provides a novel contribution for the exploration of new Prussian blue analogues and bestows a newer concept for electrode material design.

Metal-organic framework-derived metal oxide nanoparticles@reduced graphene oxide composites as cathode materials for rechargeable aluminium-ion batteries

The use of metal oxides as electrode materials has seen great success in lithium-ion batteries. However, this type of electrode materials has been regarded as an improper option for rechargeable aluminium-ion batteries (AIBs) in comparison with sulfides and selenides, and has, thus, been nearly abandoned. Here, we demonstrate the suitability of metal oxides as cathode materials of AIBs, exhibiting high electrochemical activities toward Al-ion storage. We designed economical metal-oxide cathodes (Co3O4@reduced graphene oxide (rGO), Fe2O3@rGO, and CoFe2O4@rGO) for AIBs. The Co3O4@rGO displayed superior electrochemical properties, regarding both capacity and lifespan, to the current state-of-the-art cathode material reported by scientific literature. Furthermore, the CoFe2O4@rGO exhibits rational electrochemical capacities and an extremely stable charge/discharge process with an excellent Coulombic efficiency of 99.6%. The proposed study expects to stimulate researchers to focus on the overlooked metal oxides as competitive cathode materials for high performance AIBs.

Graphite carbon-encapsulated metal nanoparticles derived from Prussian blue analogs growing on natural loofa as cathode materials for rechargeable aluminum-ion batteries

Aluminum-ion batteries (AIBs) are attracting increasing attention as a potential energy storage system owing to the abundance of Al sources and high charge density of Al³⁺. However, suitable cathode materials to further advance high-performing AIBs are unavailable. Therefore, we demonstrated the compatibility of elemental metal nanoparticles (NPs) as cathode materials for AIBs. Three types of metal NPs (Co@C, Fe@C, CoFe@C) were formed by in-situ growing Prussian blue analogs (PBAs, Co[Co(CN)₆], Fe[Fe(CN)₆] and Co[Fe(CN)₆]) on a natural loofa (L) by a room-temperature wet chemical method in aqueous bath, followed by a carbonization process. The employed L effectively formed graphite C-encapsulated metal NPs after heat treatment. The discharge capacity of CoFe@C was superior (372 mAh g⁻¹) than others (103 mAh g⁻¹ for Co@C and 75 mAh g⁻¹ for Fe@C). The novel design results in CoFe@C with an outstanding long-term charge/discharge cycling performance (over 1,000 cycles) with a Coulombic efficiency of 94.1%. Ex-situ X-ray diffraction study indicates these metal NP capacities are achieved through a solid-state diffusion-limited Al storage process. This novel design for cathode materials is highly significant for the further development of advanced AIBs in the future.

Two-dimensional boron nitride as a sulfur fixer for high performance rechargeable aluminum-sulfur batteries

Aluminum-ion batteries (AIBs) are regarded as promising candidates for post-lithium-ion batteries due to their lack of flammability and electrochemical performance comparable to other metal-ion batteries. The lack of suitable cathode materials, however, has hindered the development of high-performing AIBs. Sulfur is a cost-efficient material, having distinguished electrochemical properties, and is considered an attractive cathode material for AIBs. Several pioneering reports have shown that aluminum-sulfur batteries (ASBs) exhibit superior electrochemical capacity over other cathode materials for AIBs. However, a rapid decay in the capacity is a huge barrier for their practical applications. Here, we have demonstrated systematically for the first time that the two-dimensional layered materials (e.g. MoS2, WS2, and BN) can serve as fixers of S and sulfide compounds during repeated charge/discharge processes; BN/S/C displays the highest capacity of 532 mAh g-1 (at a current density of 100 mA g-1) compared with the current state-of-the-art cathode material for AIBs. Further, we could improve the life-span of ASBs to an unprecedented 300 cycles with a high Coulombic efficiency of 94.3%; discharge plateaus at ~1.15 V vs. AlCl4-/Al was clearly observed during repeated charge/discharge cycling. We believe that this work opens up a new method for achieving high-performing ASBs.

Water Splitting Exceeding 17% Solar-to-Hydrogen Conversion Efficiency Using Solution-Processed Ni-Based Electrocatalysts and Perovskite/Si Tandem Solar Cell

Various noble metal-free electrocatalysts have been explored to enhance the overall water splitting efficiency. Ni-based compounds have attracted substantial attention for achieving efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysts. Here, we show superior electrocatalysts based on NiFe alloy electroformed by a roll-to-roll process. NiFe (oxy)hydroxide synthesized by an anodization method for the OER catalyst shows an overpotential of 250 mV at 10 mA cm^-2, which is dramatically smaller than that of bare NiFe alloy with an overpotential of 380 mV at 10 mA cm^-2. Electrodeposited NiMo films for the HER catalyst also exhibit a small overpotential of 100 mV at 10 mA cm^-2 compared with that of bare NiFe alloy (550 mV at 10 mA cm^-2). A combined spectroscopic and electrochemical analysis reveals a clear relationship between the surface chemistry of NiFe (oxy)hydroxide and the water splitting properties. These outstanding fully solution-processed catalysts facilitate superb overall water splitting properties due to enlarged active surfaces and highly active catalytic properties. We combined a solution-processed monolithic perovskite/Si tandem solar cell with MAPb(I_0.85Br_0.15)₃ for the direct conversion of solar energy into hydrogen energy, leading to the high solar-to-hydrogen efficiency of 17.52%. Based on the cost-effective solution processes, our photovoltaic-electrocatalysis (PV-EC) system has advantages over latest high-performance solar water splitting systems.

Tailoring of Interfacial Band Offsets by an Atomically Thin Polar Insulating Layer To Enhance the Water-Splitting Performance of Oxide Heterojunction Photoanodes

An important factor in the performance of photoelectrochemical water splitting is the band edge alignment of the photoelectrodes for efficient transport and transfer of photogenerated carriers. Many studies for improving charge transfer ability between the electrode and the electrolyte have been reported, while research to improve charge transfer at the interface of the photoactive semiconductor and the conducting substrate is largely lacking. Here, we demonstrate that the water-splitting performance of an oxide heterostructured photoelectrode can be increased 6-fold by inserting an atomically thin polar LaAlO₃ interlayer compared with that of an oxide heterostructure without an insertion to modify interfacial band offsets. The electrically lowered Schottky barrier is driven by the atomically thin layer, and the charge transfer resistance between the oxides is reduced by up to 2 orders of magnitude upon insertion of LaAlO₃, a wide-gap (5.6 eV) insulator. We show that the critical thickness of the polar layer for enhancing the charge transfer is 3 unit cells. The dipole moment from the polar sheets of LaAlO₃ introduces an internal electric field, which modifies the effective band offsets in the device. This work serves as a proof of concept that photoelectrochemical performance can be improved by manipulating the band offsets of the heterostructure interface, suggesting a new design strategy for heterostructured water-splitting photoelectrodes.

Realization of Lithium-Ion Capacitors with Enhanced Energy Density via the Use of Gadolinium Hexacyanocobaltate as a Cathode Material

Li-ion storage devices having superior energy density are critical for one-time-charge long-term applications. Currently, much research endeavor is directed at enhancing the energy density of hybrid Li-ion capacitors, which incorporate the high energy of conventional Li-ion batteries with the elevated power density of Li-ion supercapacitors. Herein, we prepare orthorhombic GdCo(CN)₆ as a new Prussian blue analogue (PBA), showing that this compound offers excellent energy/power densities (605 W·h kg^-1 and 174 W kg^-1, respectively) and features Li-ion storage capacities (352 and 258 mA·h g_electrode^-1 at 100 and 1000 mA g^-1, respectively) that are almost twice higher than those of other cathode materials utilized in hybrid Li-ion capacitors. Thus, this study not only opens a new path for the exploration of new-type PBAs, but also provides insights on the use of lanthanides in energy storage applications.

Fabrication of a WS2/p-Si Heterostructure Photocathode Using Direct Hybrid Thermolysis

P-N heterostructures based on transition-metal dichelcongenides (TMDs) and a conventional semiconductor, such as p-Si, have been considered a promising structure for next-generation electronic devices and applications. However, synthesis of high-quality, wafer-scale TMDs, particularly WS₂ on p-Si, is challenging. Herein, we propose an efficient method to directly grow WS₂ crystals on p-Si via a hybrid thermolysis process. The WO₃ is deposited to prepare the p-Si surface for coating of the (NH₄)₂WS₄ precursor and converted to WS₂/p-Si during thermolysis. Moreover, the WS₂/p-Si heterojunction photocathode is fabricated and used in solar hydrogen production. The fabricated n-WS₂/p-Si heterojunction provided an onset potential of +0.022 V at 10 mA/cm² and a benchmark current density of -9.8 ± 1.2 mA/cm² at 0 V. This method reliably and efficiently produced high-quality, wafer-scale WS₂ crystals and overcame the challenges associated with previous approaches. The approach developed in this research demonstrates a magnificent progress in the fabrication of 2D material-based electronic devices.

Risk factors outperform intracranial large artery stenosis predicting unfavorable outcomes in patients with stroke

Background

This study examined how intracranial large artery stenosis (ILAS), symptomatic and asymptomatic ILAS, and risk factors affect unfavorable outcome events after medical treatment in routine clinical practice.

Methods

This was a 24-month prospective observational study of consecutively recruited stroke patients. All participants underwent magnetic resonance angiography, and their clinical characteristics were assessed. Outcome events were vascular outcome, recurrent stroke, and death. Cox regression analyses were performed to identify potential factors associated with an unfavorable outcome, which included demographic and clinical characteristics, the risk factors, and stenosis status.

Results

The analysis included 686 patients; among them, 371 were assessed as ILAS negative, 231 as symptomatic ILAS, and 84 as asymptomatic ILAS. Body mass index (p < .05), hypertension (p = .01), and old infarction (p = .047) were factors relating to vascular outcomes. Hypertension was the only factor for recurrent stroke (p = .035). Poor glomerular filtration rate (< 30 mL/min/1.73 m²) (p = .011) and baseline National Institutes of Health Stroke Scale scores (p < .001) were significant predictors of death.

Conclusions

This study extended previous results from clinical trials to a community-based cohort study by concurrently looking at the presence/absence of stenosis and a symptomatic/asymptomatic stenotic artery. Substantiated risk factors rather than the stenosis status were predominant determinants of adverse outcome. Although the degree of stenosis is often an indicator for treatment, we suggest risk factors, such as hypertension and renal dysfunction, should be monitored and intensively treated.

Layered metal-organic framework based on tetracyanonickelate as a cathode material for in situ Li-ion storage

Prussian blue analogs (PBAs) formed with hexacyanide linkers have been studied for decades. The framework crystal structure of PBAs mainly benefits from the six-fold coordinated cyano functional groups. In this study, in-plane tetracyanonickelate was utilized to engineer an organic linker and design a family of four-fold coordinated PBAs (FF-PBAs; Fe2+Ni(CN)4, MnNi(CN)4, Fe3+Ni(CN)4, CuNi(CN)4, CoNi(CN)4, ZnNi(CN)4, and NiNi(CN)4), which showed an interesting two-dimensional (2D) crystal structure. It was found that these FF-PBAs could be utilized as cathode materials of Li-ion batteries, and the Ni/Fe2+ system exhibited superior electrochemical properties compared to the others with a capacity of 137.9 mA h g-1 at a current density of 100 mA g-1. Furthermore, after a 5000-cycle long-term repeated charge/discharge measurement, the Ni/Fe2+ system displayed a capacity of 60.3 mA h g-1 with a coulombic efficiency of 98.8% at a current density of 1000 mA g-1. In addition, the capacity of 86.1% was preserved at 1000 mA g-1 as compared with that at 100 mA g-1, implying a good rate capability. These potential capacities can be ascribed to an in situ reduction of Li+ in the interlayer of Ni/Fe2+ instead of the formation of other compounds with the host material according to ex situ XRD characterization. These specially designed FF-PBAs are expected to inspire new concepts in electrochemistry and other applications requiring 2D materials.

Peanut allergy and oral immunotherapy

Peanut allergy is the commonest cause of food-induced anaphylaxis in the world, and it can be fatal. There have been many recent improvements to achieve safe methods of peanut desensitisation, one of which is to use a combination of anti-immunoglobulin E and oral immunotherapy. We have treated 27 patients with anti-immunoglobulin E and oral immunotherapy, and report on the outcomes and incidence of adverse reactions encountered during treatment. The dose of peanut protein tolerated increased from a median baseline of 5 to 2000 mg after desensitisation, which is substantially more than would be encountered through accidental ingestion. The incidence of adverse reactions during the escalation phase of oral immunotherapy was 1.8%, and that during the maintenance phase was 0.6%. Most adverse reactions were mild; three episodes were severe enough to warrant withdrawal from oral immunotherapy, but none required epinephrine injection. Preliminary data suggest that unresponsiveness is lost when daily ingestion of peanuts is stopped after the maintenance period.

All-Solution-Processed WO3/BiVO4 Core-Shell Nanorod Arrays for Highly Stable Photoanodes

Tungsten oxide (WO₃) and bismuth vanadate (BiVO₄) are one of the most attractive combinations to construct an efficient heterojunction for photoelectrochemical (PEC) applications. Here, we report an all-solution-processed WO₃/BiVO₄ heteronanostructure photoanode with highly enhanced photoactivity and stability for sustainable energy production. The vertically aligned WO₃ nanorods were synthesized on a fluorine-doped tin oxide/glass substrate by the hydrothermal method without a seed layer and BiVO₄ was deposited by pulsed electrodeposition for conformal coating. Owing to the long diffusion lengths of charge carriers in the WO₃ nanorods, the ability to absorb the wider range of wavelengths, and appropriate band-edge positions of the WO₃/BiVO₄ heterojunction for spontaneous PEC reaction, the optimum WO₃/BiVO₄ photoanode has a photocurrent density of 4.15 mA/cm² at 1.23 V versus RHE and an incident-photon-to-current efficiency of 75.9% at 430 nm under front illumination, which are a double and quadruple those of pristine WO₃ nanorod arrays, respectively. Our work suggests an environment-friendly and low-cost all-solution process route to synthesize high-quality photoelectrodes.

Emulsified polycolloid substrate biobarrier for benzene and petroleum-hydrocarbon plume containment and migration control - A field-scale study

The objective of this field-scale study was to assess the effectiveness of applying an emulsified polycolloid substrate (EPS; containing cane molasses, soybean oil, and surfactants) biobarrier in the control and remediation of a petroleum-hydrocarbon plume in natural waters. An abandoned petrochemical manufacturing facility site was contaminated by benzene and other petroleum products due to a leakage from a storage tank. Because benzene is a petroleum hydrocarbon with a high migration ability, it was used as the target compound in the field-scale study. Batch partition and sorption experiment results indicated that the EPS to water partition coefficient for benzene was 232 mg/mg at 25 °C. This suggests that benzene had a higher sorption affinity to EPS, which decreased the benzene concentrations in groundwater. The EPS solution was pressure-injected into three remediation wells (RWs; 150 L EPS in 800 L groundwater). Groundwater samples were collected from an upgradient background well, two downgradient monitor wells (MWs), and the three RWs for analyses. EPS injection increased total organic carbon (TOC) concentrations (up to 786 mg/L) in groundwater, which also resulted in the formation of anaerobic conditions. An abrupt drop in benzene concentration (from 6.9 to below 0.04 mg/L) was observed after EPS supplementation in the RWs due to both sorption and biodegradation mechanisms. Results show that the EPS supplement increased total viable bacteria and enhanced bioremediation efficiency, which accounted for the observed decrease in benzene concentration. The first-order decay rate in RW1 increased from 0.003 to 0.023 d^-1 after EPS application. Injection of EPS resulted in significant growth of indigenous bacteria, and 23 petroleum-hydrocarbon-degrading bacterial species were detected, which enhanced the in situ benzene biodegradation efficiency. Results demonstrate that the EPS biobarrier can effectively contain a petroleum-hydrocarbon plume and prevent its migration to downgradient areas, which reduces the immediate risk presented to downgradient receptors.

Daylight-Induced Metal-Insulator Transition in Ag-Decorated Vanadium Dioxide Nanorod Arrays

Metal-insulator transition (MIT) in strongly correlated electronic materials has enormous potential with scientific and technological impacts in future oxide nanoelectronic devices. Although photo-induced MIT can provide opportunities to extend the novel functionality of strongly correlated electronic materials, there have rarely been reports on it. Here, we report MIT provoked by visible-near-infrared light in Ag-decorated VO₂ nanorod arrays (NRs) because of localized surface plasmon resonance (LSPR) and its application to broadband photodetectors. Our simulation results based on the finite-difference time-domain method show that the electric field resulting from LSPR can be generated at the interface between Ag nanoparticles and VO₂ layers under vis NIR illumination. Using high-resolution transmission electronic microscopy and Raman spectroscopy, we observe the MIT and structural phase transition in the Ag-decorated VO₂ NRs due to the LSPR effect. The optoelectronic measurements confirm that high, fast, and broad photoresponse of Ag-decorated VO₂ NRs is attributed to photo-induced MIT due to LSPR. Our study will open up a new strategy to trigger MIT in strongly correlated electronic materials through functionalization with plasmonic nanoparticles and serve as a valuable proof of concept for next-generation optoelectronic devices with fast response, low power consumption, and high performance.

SnS2 Nanograins on Porous SiO2 Nanorods Template for Highly Sensitive NO2 Sensor at Room Temperature with Excellent Recovery

In order to develop high performance chemoresistive gas sensors for Internet of Everything applications, low power consumption should be achieved due to the limited battery capacity of portable devices. One of the most efficient ways to reduce power consumption is to lower the operating temperature to room temperature. Herein, we report superior gas sensing properties of SnS₂ nanograins on SiO₂ nanorods toward NO₂ at room temperature. The gas response is as high as 701% for 10 ppm of NO₂ with excellent recovery characteristics and the theoretical detection limit is evaluated to be 408.9 ppb at room temperature, which has not been reported for SnS₂-based gas sensors to the best of our knowledge. The SnS₂ nanograins on the template used in this study have excessive sulfur component (Sn:S = 1:2.33) and exhibit p-type conduction behavior. These results will provide a new perspective of nanostructured two-dimensional materials for gas sensor applications on demand.

Application of an emulsified polycolloid substrate biobarrier to remediate petroleum-hydrocarbon contaminated groundwater

Emulsified polycolloid substrate (EPS) was developed and applied in situ to form a biobarrier for the containment and enhanced bioremediation of a petroleum-hydrocarbon plume. EPS had a negative zeta potential (-35.7 mv), which promoted its even distribution after injection. Batch and column experiments were performed to evaluate the effectiveness of EPS on toluene containment and biodegradation. The EPS-to-water partition coefficient for toluene (target compound) was 943. Thus, toluene had a significant sorption affinity to EPS, which caused reduced toluene concentration in water phase in the EPS/water system. Groundwater containing toluene (18 mg/L) was pumped into the three-column system at a flow rate of 0.28 mL/min, while EPS was injected into the second column to form a biobarrier. A significant reduction of toluene concentration to 0.1 mg/L was observed immediately after EPS injection. This indicates that EPS could effectively contain toluene plume and prevent its further migration to farther downgradient zone. Approximately 99% of toluene was removed after 296 PVs of operation via sorption, natural attenuation, and EPS-enhanced biodegradation. Increase in total organic carbon and bacteria were also observed after EPS supplement. Supplement of EPS resulted in a growth of petroleum-hydrocarbon degrading bacteria, which enhanced the toluene biodegradation.

Hong Kong Institute of Allergy and Hong Kong Society for Paediatric Immunology Allergy & Infectious Diseases joint consensus statement 2018 on vaccination in egg-allergic patients

Vaccination of egg-allergic individuals has been a historical concern, particularly for influenza and measles-mumps-rubella-varicella vaccines that are developed in chicken egg embryos or chicken cell fibroblasts. The egg proteins in these vaccines were believed to trigger an immediate allergic reaction in egg-allergic individuals. However, recently published international guidelines have updated their recommendations and now state that these vaccines can be safely administered to egg-allergic individuals. This joint consensus statement by the Hong Kong Institute of Allergy and the Hong Kong Society for Paediatric Immunology Allergy & Infectious Diseases summarises the updates and provides recommendations for local general practitioners and paediatricians. Hong Kong Institute of Allergy and Hong Kong Society for Paediatric Immunology Allergy & Infectious Diseases joint consensus statement 2018 on vaccination in egg-allergic patients Background.