Dual-Functional Tungsten-Doped NiO for Highly Sensitive Triethylamine Sensor with ppb Level Detection Limit.

In this study, the W-doped Nickel oxide (NiO) nanoflowers were synthesized using a straightforward hydrothermal method, significantly enhancing the sensing performance toward triethylamine through dual-functional tungsten doping. The optimal doping concentration not only increased the specific surface area of NiO from 25.54 to 189.19 m2 g-1 but also reduced the formation energy of oxygen vacancies. The sensor containing 4 at % W-doped NiO demonstrated exceptional sensitivity to triethylamine, achieving a detection level as high as 229.0 for concentrations of 100 ppm at 237.5 °C. This triethylamine sensor represents a 135-fold enhancement over sensors fabricated from undoped NiO, and offers a rapid response/recovery time of 8 and 30 s, respectively. Furthermore, at a lower triethylamine concentration of 50 ppb, indicating a lower detection limit.

Extraordinary Thermoelectric Properties of Topological Surface States in Quantum-Confined Cd3As2 Thin Films.

Topological insulators and semimetals have been shown to possess intriguing thermoelectric properties promising for energy harvesting and cooling applications. However, thermoelectric transport associated with the Fermi arc topological surface states on topological Dirac semimetals remains less explored. This work systematically examines thermoelectric transport in a series of topological Dirac semimetal Cd3As2 thin films grown by molecular beam epitaxy. Surprisingly, significantly enhanced Seebeck effect and anomalous Nernst effect are found at cryogenic temperatures when the Cd3As2 layer is thin. In particular, a peak Seebeck coefficient of nearly 500 µV K-1 and a corresponding thermoelectric power factor over 30 mW K-2 m-1 are observed at 5 K in a 25-nm-thick sample. Combining angle-dependent quantum oscillation analysis, magnetothermoelectric measurement, transport modeling, and first-principles simulation, the contributions from bulk and surface conducting channels are isolated and the unusual thermoelectric properties are attributed to the topological surface states. The analysis showcases the rich thermoelectric transport physics in quantum-confined topological Dirac semimetal thin films and suggests new routes to achieving high thermoelectric performance at cryogenic temperatures.

Dynamic Manipulation of Droplets on Liquid-Infused Surfaces Using Photoresponsive Surfactant.

Fast and programmable transport of droplets on a substrate is desirable in microfluidic, thermal, biomedical, and energy devices. Photoresponsive surfactants are promising candidates to manipulate droplet motion due to their ability to modify interfacial tension and generate "photo-Marangoni" flow under light stimuli. Previous works have demonstrated photo-Marangoni droplet migration in liquid media; however, migration on other substrates, including solid and liquid-infused surfaces (LIS), remains an outstanding challenge. Moreover, models of photo-Marangoni migration are still needed to identify optimal photoswitches and assess the feasibility of new applications. In this work, we demonstrate 2D droplet motion on liquid surfaces and on LIS, as well as rectilinear motion in solid capillary tubes. We synthesize photoswitches based on spiropyran and merocyanine, capable of tension changes of up to 5.5 mN/m across time scales as short as 1.7 s. A millimeter-sized droplet migrates at up to 5.5 mm/s on a liquid, and 0.25 mm/s on LIS. We observe an optimal droplet size for fast migration, which we explain by developing a scaling model. The model also predicts that faster migration is enabled by surfactants that maximize the ratio between the tension change and the photoswitching time. To better understand migration on LIS, we visualize the droplet flow using tracer particles, and we develop corresponding numerical simulations, finding reasonable agreement. The methods and insights demonstrated in this study enable advances for manipulation of droplets for microfluidic, thermal and water harvesting devices.

Skin sympathetic nerve activity as a biomarker for outcomes in spontaneous intracerebral hemorrhage.

OBJECTIVE: A rapid and accurate forecast for the early prognosis of ICH patients is challenging. This study investigated whether heart rate variability (HRV) and skin sympathetic nerve activity (SKNA) could prognosticate poor neurological outcomes in ICH patients. METHODS: Between November 2020 and November 2021, we studied 92 spontaneous ICH patients in the First Affiliated Hospital of Nanjing Medical University. Glasgow Outcome Scale (GOS) score at 2 weeks after the ICH was used to categorize patients into good and poor outcome groups. The modified Rankin Scale (mRS) assessed patients' ability to live independently for 1 year. We utilized a portable high-frequency electrocardiogram (ECG) recording system to record the HRV and SKNA information in ICH patients and control participants. RESULTS: 77 patients were eligible for the prediction of neurological outcome and were allocated into the good (n = 22) or poor (n = 55) outcome groups based on the GOS grade. In univariate logistic regression analysis, significant variables that could differentiate the outcomes were age, hypertension, tracheal intubation, Glasgow Coma Scale (GCS) score, existing intraventricular hemorrhage, white blood cells, neutrophil, lnVLF, lnTP, and aSKNA. Variables in the best fit multivariable logistic regression model were age, hypertension, GCS score, neutrophils, and aSKNA. The GCS score was the only independent risk factor for poor outcomes. At 30 days and 1 year of follow-up, patients with lower aSKNA had poor outcomes. INTERPRETATION: ICH patients had reduced aSKNA, which could be a prognostic indicator. A lower aSKNA suggested a worse prognosis. The present data indicate that ECG signals could be helpful for prognosticating ICH patients.

Depinning of Multiphase Fluid Using Light and Photo-Responsive Surfactants.

The development of noninvasive and robust strategies for manipulation of droplets and bubbles is crucial in applications such as boiling and condensation, electrocatalysis, and microfluidics. In this work, we realize the swift departure of droplets and bubbles from solid substrates by introducing photoresponsive surfactants and applying asymmetric illumination, thereby inducing a "photo-Marangoni" lift force. Experiments show that a pinned toluene droplet can depart the substrate in only 0.38 s upon illumination, and the volume of an air bubble at departure is reduced by 20%, indicating significantly faster departure. These benefits can be achieved with moderate light intensities and dilute surfactant concentrations, without specially fabricated substrates, which greatly facilitates practical applications. Simulations suggest that the net departure force includes contributions from viscous stresses directly caused by the Marangoni flow, as well as from pressure buildup due to flow stagnation at the contact line. The manipulation scheme proposed here shows potential for applications requiring droplet and bubble removal from working surfaces.

Role of sST2 in predicting recurrence of atrial fibrillation after radiofrequency catheter ablation.

INTRODUCTION: Atrial fibrosis is associated with atrial fibrillation (AF) recurrence after ablation. This study aims to determine the relationship between soluble ST2 (sST2), a profibrotic biomarker, and AF recurrence after radiofrequency catheter ablation (RFCA). METHODS: AF patients referred for RFCA were consecutively included from October 2017 to May 2019. Baseline characteristics were collected, and sST2 levels were determined before ablation. Left atrial substrate mapping was performed after circumferential pulmonary vein isolation under sinus rhythm, and substrate was modified in low-voltage zones. A second procedure was recommended under recurrence. RESULTS: Two hundred fifty-eight patients (146 males, average age 61.0 ± 8.8) were included. After a medium follow-up of 13.5 months, 52 patients (20.2%) had recurrence and received a second procedure. Preoperative sST2 level in patients with recurrence was significantly higher than that in patients without (31.3 ng/mL vs 20.3 ng/mL, P < .001). In those undergoing second ablation, sST2 level in patients with new abnormalities during endocardial mapping was significantly higher than that in patients without (43.0 ng/mL vs 22.1 ng/mL, P < .001). An sST2 level over 26.9 ng/mL could predict AF recurrence with new abnormalities during endocardial mapping with a sensitivity of 100% and a specificity of 75.9%. Multiple logistic analysis showed that sST2 level was an independent predictor of AF recurrence with new abnormalities during endocardial mapping (P < .001). CONCLUSIONS: sST2 level was associated with new abnormalities during endocardial mapping and recurrence of AF after ablation. It might have significance in choosing treatment strategies for AF.

Photoinduced Defect Engineering: Enhanced Photothermal Catalytic Performance of 2D Black In2 O3- x Nanosheets with Bifunctional Oxygen Vacancies.

Photothermal CO2 reduction technology has attracted tremendous interest as a solution for the greenhouse effect and energy crisis, and thereby it plays a critical role in solving environmental problems and generating economic benefits. In2 O3- x has emerged as a potential photothermal catalyst for CO2 conversion into CO via the light-driven reverse water gas shift reaction. However, it is still a challenge to modulate the structural and electronic characteristics of In2 O3 to enhance photothermocatalytic activity synergistically. In this work, a novel route to activate inert In(OH)3 into 2D black In2 O3- x nanosheets via photoinduced defect engineering is proposed. Theoretical calculations and experimental results verify the existence of bifunctional oxygen vacancies in the 2D black In2 O3- x nanosheets host, which enhances light harvesting and chemical adsorption of CO2 molecules dramatically, achieving 103.21 mmol gcat -1 h-1 with near-unity selectivity for CO generation and meanwhile excellent stability. This study reveals an exciting phenomenon that light is an ideal external stimulus on the layered In2 O3 system, and its electronic structure can be adjusted efficiently through photoinduced defect engineering; it can be anticipated that this synthesis strategy can be extended to wider application fields.

Dye-sensitized photocathodes for oxygen reduction: efficient H2O2 production and aprotic redox reactions.

Dye-sensitized photoelectrochemical cells (DSPECs) can be used to store solar energy in the form of chemical bonds. Hydrogen peroxide (H2O2) is a versatile energy carrier and can be produced by reduction of O2 on a dye-sensitized photocathode, in which the design of dye molecules is crucial for the conversion efficiency and electrode stability. Herein, using a hydrophobic donor-double-acceptor dye (denoted as BH4) sensitized NiO photocathode, hydrogen peroxide (H2O2) can be produced efficiently by reducing O2 with current density up to 600 µA cm-2 under 1 sun conditions (Xe lamp as sunlight simulator, λ > 400 nm). The DSPECs maintain currents greater than 200 µA cm-2 at low overpotential (0.42 V vs. RHE) for 18 h with no decrease in the rate of H2O2 production in aqueous electrolyte. Moreover, the BH4 sensitized NiO photocathode was for the first time applied in an aprotic electrolyte for oxygen reduction. In the absence of a proton source, the one-electron reduction of O2 generates stable, nucleophilic superoxide radicals that can then be synthetically utilized in the attack of an available electrophile, such as benzoyl chloride. The corresponding photocurrent generated by this photoelectrosynthesis is up to 1.8 mA cm-2. Transient absorption spectroscopy also proves that there is an effective electron transfer from reduced BH4 to O2 with a rate constant of 1.8 × 106 s-1. This work exhibits superior photocurrent in both aqueous and non-aqueous systems and reveals the oxygen/superoxide redox mediator mechanism in the aprotic chemical synthesis.

CuCl2-mediated reaction of [60]fullerene with amines in the presence or absence of dimethyl acetylenedicarboxylate: preparation of fulleropyrroline or aziridinofullerene derivatives.

The CuCl2-mediated three-component reaction of C60 with amines and dimethyl acetylenedicarboxylate afforded the fulleropyrrolines in moderate yields. Furthermore, the CuCl2-mediated oxidative [2 + 1] reaction of C60 with aromatic amines bearing a strong electron-withdrawing group provided the aziridinofullerenes and the selective cis-1-bisaziridinofullerenes.

CuI-catalyzed oxidative [3 + 2] reaction of fullerene with amidines or amides using air as the oxidant: preparation of fulleroimidazole or fullerooxazole derivatives.

CuI-catalyzed oxidative reaction of amidines with C60 using air as the oxidant has been exploited for the easy preparation of fulleroimidazole derivatives. Furthermore, this kind of CuI-catalyzed [3 + 2] reaction has also been successfully applied in the synthesis of fullerooxazole derivatives starting from amides for the first time. The substrate scope is broad, and the process is particularly cheap and simple.