Mesoporous CdO/CdGa2O4 microsphere for rapidly detecting triethylamine at ppb level.

Developing fast, accurate and sensitive triethylamine gas sensors with low detection limits is paramount to ensure the safety of workers and the public. However, sensors based on single metal oxide materials still suffer from drawbacks such as low response sensitivity and long response and recovery times. To address these challenges, in this work, a series of mesoporous CdO/CdGa2O4 microspheres were synthesized. We optimized the sensor's sensing performance to triethylamine by fine-tuning the ratio of CdO to CdGa2O4. Among them, CdO:3CdGa2O4-based sensor demonstrates a rapid response time of 2 s to detect 100 ppm of triethylamine, with a high response value of 211 and exceptional selectivity. Furthermore, it exhibits a low detection limit of 20 ppb for triethylamine, making it suitable for practically testing fish freshness. Crucially, electron transfer between the heterojunctions increases the chemically adsorbed oxygen on the materials' surface, thereby enhancing the sensor's response sensitivity to triethylamine. This discovery provides new insights and methodologies for the design of highly efficient triethylamine gas sensors.

Essential role of lattice oxygen in hydrogen sensing reaction.

Understanding the sensing mechanism of metal oxide semiconductors is imperative to the development of high-performance sensors. The traditional sensing mechanism only recognizes the effect of surface chemisorbed oxygen from the air but ignores surface lattice oxygen. Herein, using in-situ characterizations, we provide direct experimental evidence that the surface chemisorbed oxygen participated in the sensing process can come from lattice oxygen of the oxides. Further density functional theory (DFT) calculations prove that the p-band center of O serves as a state of art for regulating the participation of lattice oxygen in gas-sensing reactions. Based on our experimental data and theoretical calculations, we discuss mechanisms that are fundamentally different from the conventional mechanism and show that the easily participation of lattice oxygen is helpful for the high response value of the materials.

Analysis of Risk Factors for Carbapenem Resistant Klebsiella pneumoniae Infection and Construction of Nomogram Model: A Large Case-Control and Cohort Study from Shanxi, China.

Background: Healthcare-associated infections caused by carbapenem-resistant Klebsiella pneumoniae (CRKP) are now a global public health problem, increasing the burden of disease and public healthcare expenditures in various countries. The aim of this study was to analyse the risk factors for CRKP infections and to develop nomogram models to help clinicians predict CRKP infections at an early stage to facilitate diagnosis and treatment. Methods: The clinical data of patients with Klebsiella pneumoniae (KP) infections in our hospital from January 2018 to January 2023 were collected. 174 patients with CRKP infections and 219 patients with CSKP infections were selected for case-control study. 27 predictors related to CRKP infections were determined. The least absolute shrinkage and selection operator (Lasso) regression was used to screen the characteristic variables, Multivariate logistic regression analysis was performed on the selected variables and a nomogram model was established. The discrimination and calibration of the nomogram model were evaluated by receiver operator curves (ROC) and calibration curves. Results: Six predictive factors of ICU stay, fever time, central venous catheterization time, catheter indwelling time, carbapenem use and tetracycline use screened by lasso regression were included in the logistic regression model, and the nomogram was drawn to visualize the results. The area under ROC curve of training set and validation set was 0.894 (95% CI: 0.857, 0.931) and 0.872 (95% CI: 0.805, 0.939); The results of decision curve analysis also show that the model has good prediction accuracy. Conclusion: This study established a nomogram to predict CRKP infection based on lasso-logistic regression model, which has certain guiding significance for early diagnosis of CRKP infections.

Optimization of target system for the production of 99Mo via 100Mo(γ,n)99Mo reaction.

With an increase of stopping operation of nuclear reactors worldwide, the supply of medical 99Mo becomes difficult and thus many efforts have been made to find an alternative. A process based on an electron linear accelerator (linac) system and a100Mo target via the 100Mo (γ,n)99Mo reaction receives a lot of attention due to the relatively low level of co-produced impurities. This process has been recently developed at the Institute of Modern Physics (IMP) and the Monte Carlo simulation was used to optimize the target system before operating pilot irradiation experiments. First, tungsten and tantalum, as mostly used converter materials, were tested. The yield of 99Mo was evaluated with respect to the converter thickness and the electron beam energy by means of Geant4 simulations. Besides, the specific activity of 99Mo produced from one-stage approach (100Mo target without a converter) and two-stage approach (100Mo target with a converter) was compared when varying the testing conditions. The two-stage approach was selected for the experiment due to the higher specific activity of produced 99Mo at all tested conditions. A target consisting of a 10 mm thickness of the 100Mo tablets and a 2.4 mm thick Ta converter was irradiated for 40 h (50 MeV with 0.2 µA). The Geant4-calculated specific activity of generated 99Mo at the end of bombardment agreed well with the experimental value, which proved high level of accuracy of the Geant4 simulation. In future studies, the Geant4 simulation will be used to optimize the production process when using high power linac system.

Investigating the quality of life for children with autism spectrum disorder scale using Rasch methodology.

Our purpose in this study was to provide additional psychometric evidence of the Quality of Life for Children with Autism Spectrum Disorder (QOLASD-C) scale. We used Rasch modeling to investigate the QOLASD-C functioning, the characteristics of the items comprising the scale, and the item functioning across subgroups of children with ASD based on gender and race/ethnicity. Results showed that QOLASD-C was unidimensional, met the local independence assumption, and measured quality of life (QOL). The items showed excellent fit to the model and good discriminating ability between low and high QOL. Most items showed a moderate difficulty level. No differential item functioning was observed based on children's gender and race/ethnicity. Implications for research and practice are discussed.

Examining intervention hours attended for couples randomly assigned to receive relationship education.

Relationship education (RE) has shown promise as an effective intervention for couples. Yet, challenges exist with retaining low-income couples and federal funding required that grantees provide at least 12 h of core content. We conducted a follow-up analysis to a randomized trial of RE with low-income couples. We focused on couples randomly assigned to the treatment (N = 579) and examined the influence of intervention hours on emotion regulation, dyadic coping, and individual distress at 1 and 6-month follow-up. Results of longitudinal actor-partner interdependence models indicated that women who completed the program reported fewer difficulties in emotion regulation at 6-month follow-up than women who attended fewer intervention hours. Additionally, men who completed reported more individual distress at 1-month follow-up than men who attended fewer hours. Given that most couples were Hispanic, we conducted an exploratory analysis to examine language as a covariate with mixed results.

Production of medical isotope 68Ge based on a novel chromatography separation technique and assembling of 68Ge/68Ga generator.

A double-column chromatography separation technique was involved for isolation of 68Ge from a bombarded Ga-Ni alloy target. About 185 MBq 68Ge obtained was used for assembling SnO2-based 68Ge/68Ga generator. Approximately 70% of 68Ga in high radioactivity concentration was eluted from generator with excellent radionuclidic, radiochemical and chemical purity. 68Ga was quite adequate for radiolabeling with DOTATATE or PSMA-617 with a high labelling efficiency of >92%. The double-column chromatography technique possessed a potential application prospect of 68Ge/68Ga production, aiding the development of 68Ga in nuclear medicine.

Distribution of Anthropogenic 129I in the Western South China Sea and Its Application for Tracing the Sources and Movement of Pollution.

Anthropogenic 129I has been dispersed all over the world and could be utilized as an oceanographic tracer based on its conservative nature in the ocean. The first datasets of 129I and 127I were obtained by analysis of seawater of 36 water columns collected in the western South China Sea during August-September 2018. The measured 129I concentrations decreased with depth from (0.93-1.61) × 107 atoms/L in the upper 200 m to (0.04-0.14) × 107 atoms/L at 1500 m, indicating a clear anthropogenic source in the upper layer, mainly originated from the global fallout. The riverine input of the deposited 129I on the catchment area of the Mekong River is an important source besides the direct deposition in the seas. The water mass with high 129I from the Mekong River water moves to the east at 11°N by the North Nansha Current in the surface layer (2-25 m). The exponentially decreasing 129I level with depth indicates that the vertical dispersion of 129I from the upper to the lower layer was mainly through slow diffusion, and the deep water at more than 1500 m was not significantly contaminated by the upper layer water at least in the past 70 years.

A randomized trial of relationship education using Within Our Reach for economically vulnerable couples.

Couples relationship education is grounded in teaching couples' skills and strategies to form and sustain healthy relationships. The purpose of this investigation was to examine the impact of a relationship education intervention on emotion regulation, individual distress, dyadic coping, and relationship adjustment utilizing a randomized control trial for economically vulnerable couples. The analysis sample included 1418 couples (2836 individuals) who were randomly assigned to receive the 12-h Within Our Reach curriculum immediately, or to a wait-list control group. We estimated multilevel growth curve models over time among outcomes between treatment and wait-list control conditions. Treatment group couples demonstrated statistically significant improvements over the 6-month study period on emotional regulation and dyadic coping when compared to their wait-list group counterparts. Although models showed improvements in individual distress and relationship adjustments, these improvements did not amount to statistically significant group differences. Implications and limitations are also noted.

A preliminary investigation of psychometric properties of the youth-reported Pediatric Symptom Checklist (PSC-Y) in Chinese elementary, middle, and high schools.

The current study validated the youth-reported Pediatric Symptom Checklist-Youth (PSC-Y) using a Chinese youth sample (N = 20,996). The factor structure, measurement invariance, and criterion validity were examined. First, factor analysis documented that the correlated three-factor structure, including externalizing problems, internalizing problems, and attention problems fit the data best, which aligns with the prior factor structure of the PSC-Y in other settings (e.g., teacher ratings). In addition, measurement invariance was established across gender and age groups. The latent mean differences revealed that middle and high school students and females reported more internalizing and attention problems than elementary students and males. Additionally, high school students and females were less likely to report externalizing problems than elementary students and males. Finally, the criterion validity of the PSC-Y was established using external scales assessing subjective wellbeing and prosocial behavior. Teachers, school administrators, and school psychologists can utilize the results of this study to more precisely identify youth at risk for psychosocial problems.

Functional Aerogels Composed of Regenerated Cellulose and Tungsten Oxide for UV Detection and Seawater Desalination.

Functional aerogels composed of regenerated cellulose and tungsten oxide were fabricated by implanting tungsten-oxide nanodots into regenerated cellulose fiber. This superfast photochromic property benefitted from the small size and even distribution of tungsten oxide, which was caused by the confinement effect of the regenerated cellulose fiber. The composite was characterized using XRD and TEM to illustrate the successful loading of tungsten oxide. The composite turned from pale white to bright blue under ambient solar irradiation in five seconds. The evidence of solar absorption and electron paramagnetic resonance (EPR) demonstrated the fast photochromic nature of the composite and its mechanism. Furthermore, carbon fiber filled with preferential growth tungsten-oxide nanorods was obtained by annealing the photochromic composite in a N2 atmosphere. This annealed product exhibited good absorption across the whole solar spectrum and revealed an excellent photothermal conversion performance. The water evaporation rate reached 1.75 kg m-2 h-1 under one sun illumination, which is 4.4 times higher than that of pure water. The photothermal conversion efficiency was 85%, which shows its potential application prospects in seawater desalination.

Structural Variations of Metal Oxide-Based Electrocatalysts for Oxygen Evolution Reaction.

Electrocatalytic oxygen evolution reaction (OER), an important electrode reaction in electrocatalytic and photoelectrochemical cells for a carbon-free energy cycle, has attracted considerable attention in the last few years. Metal oxides have been considered as good candidates for electrocatalytic OER because they can be easily synthesized and are relatively stable during the OER process. However, inevitable structural variations still occur to them due to the complex reaction steps and harsh working conditions of OER, thus impending the further insight into the catalytic mechanism and rational design of highly efficient electrocatalysts. The aim of this review is to disclose the current research progress toward the structural variations of metal oxide-based OER electrocatalysts. The origin of structural variations of metal oxides is discussed. Based on some typical oxides performing OER activity, the external and internal factors that influence the structural stability are summarized and then some general approaches to regulate the structural variation process are provided. Some operando methods are also concluded to monitor the structural variation processes and to identify the final active structure. Additionally, the unresolved problems and challenges are presented in an attempt to get further insight into the mechanism of structural variations and establish a rational structure-catalysis relationship.

Practicality of hierarchically macro/mesoporous γ-Al2O3 as a promising sorbent in the preparation of low specific activity 99Mo/99mTc generator.

Hierarchically macro-/mesoporous γ-Al2O3 (HMMA) was synthesized and characterized by various analytical techniques. The results indicated that HMMA possessed macropores (∼0.45 µm) and mesopores (∼10.6 nm) with a large surface area (∼542 m2 g-1). The absorption behaviors of Mo and Re with HMMA were investigated. The maximum static absorption capacity could reach about 250 mg Mo per g HMMA. The absorption equilibrium can be attained quickly within 10 mins. At initial Mo ions concertation of 10,000 mg L-1, the breakthrough capacity was determined to be around 200 mg Mo per g HMMA. Additional, absorption mechanism results indicated that Mo ions reacts strongly with a hydroxyl on the surface of γ-Al2O3 and an adjacent Al atom, simultaneously. A 9.15 mCi (339 MBq) 99Mo generator was prepared and evaluated its performance for over one week. The recovery of 99mTc could reach about 89% with favorable radionuclidic, radiochemical and chemical purity for nuclear medicine application. HMMA has a potential application prospect for the preparation of low specific activity (LSA) 99Mo/99mTc generator.

Three-dimensional porous self-assembled chestnut-like nickel-cobalt oxide structure as an electrochemical sensor for sensitive detection of hydrazine in water samples.

Three-dimensional NiCo2O4 is a kind of superior sensing material owing to its high electron transfer capability, large available surface area and numbers of active sites. In this work, NiCo2O4 of the three-dimensional chestnut-like structure were easily achieved through a one step hydrothermal process. Afterwards, the morphology and structure were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Based on the three-dimensional porous chestnut-like NiCo2O4, an electrochemical sensor for hydrazine (N2H4) detection is fabricated. This electrochemical platform can realize good selectivity, excellent stability, high sensitivity (∼2154.4 µA mM-1 cm-2), and low detection limit (0.3 µM), as well as a wide linear range from 1 µM to 1096 µM. The synergistic effect of nickel-cobalt in such mixed transition metal oxides which Co in Co3O4 is partially replaced by Ni are beneficial for enhancing sensing properties. This study proves that three-dimensional porous chestnut-like NiCo2O4 is electrochemically active for catalytic performance which is particular and promising material for good application in the practical detection of N2H4.

Host-Guest Interaction Creates Hydrogen-Evolution Electrocatalytic Active Sites in 3d Transition Metal-Intercalated Titanates.

The hydrogen evolution reaction (HER) is involved in energy-intensive water- and chlor-alkali electrolyzers, and thus, highly active and stable HER electrocatalysts in alkaline media are needed. Titanates, a family of representative two-dimensional materials with negatively charged main layers, are chemically and structurally stable under strongly basic conditions, but they have never been shown to have electrocatalytic activity for HER. Herein, we report that intercalating 3d metal cations, including Fe3+, Co2+, Ni2+, and Cu2+ ions, into the interlayer regions of titanates yields efficient and robust electrocatalysts for the alkaline HER. The intercalation of 3d metal cations in titanates is achieved by rapid cation-exchange reaction between Na+-containing titanates and 3d metal cations at room temperature. Among the 3d metal-intercalated titanates we synthesize, the Co2+-containing material is found to show the best electrocatalytic activity. Experimental and theoretical results reveal that the strong electronic interaction between 3d metal cations and negatively charged main [TiO6]∞ layers renders good catalytic activity to the outermost oxygen atoms in the [TiO6]∞ layer, further making 3d metal-intercalated titanate an efficient electrocatalyst for the HER.

Self-template construction of hollow Co3O4 microspheres from porous ultrathin nanosheets and efficient noble metal-free water oxidation catalysts.

Developing noble metal-free water oxidation catalysts is essential for many energy conversion/storage processes (e.g., water splitting). Herein, we report the facile synthesis of hollow Co3O4 microspheres composed of porous, ultrathin (<5 nm), single-crystal-like nanosheets via a novel "self-template" route. The successful preparation of these hollow Co3O4 nanomaterials includes three main steps: (1) the synthesis of solid cobalt alkoxide microspheres, (2) their subsequent self-template conversion into hollow cobalt hydroxide microspheres composed of ultrathin nanosheets, and finally (3) thermal treatment of hollow cobalt hydroxide microspheres into the hollow Co3O4 material. The as-obtained hollow Co3O4 nanomaterial possesses a high BET surface area (∼180 m(2) g(-1)), and can serve as an active and stable water oxidation catalyst under both electrochemical and photochemical reaction conditions, owing to its unique structural features. In the electrochemical water oxidation, this catalyst affords a current density of 10 mA cm(-2) (a value related to practical relevance) at an overpotential of ∼0.40 V. Moreover, with the assistance of a sensitizer [Ru(bpy)3](2+) (bpy = 2,2'-bipyridine), this nanomaterial can catalyze water oxidation reactions under visible light irradiation with an O2 evolution rate of ∼12 218 µmol g(-1) h(-1). Our results suggest that delicate nanostructuring can offer unique advantages for developing efficient water oxidation catalysts.