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[Display omitted] • Operates without external bias voltage due to the photovoltaic effect in the NbSe 2 -MoS 2 junction. • Detects NH 3 gas at concentrations ranging from 10 ppm to 500 ppm with varying responses (8.8 % to 28.8 %). • The built-in electric field and charge-transfer mechanism enhance gas specificity. • The gas sensing mechanism relies on physisorption and charge transfer at the surface of the nanostructure. Two-dimensional (2D) transition metal dichalcogenides (TMDs) have attracted significant attention for their optical and gas-sensing applications due to their exceptional sensitivity. Reliable selectivity and low power consumption are two major requirements for photodetector and gas sensor applications in next-generation electronic devices and the Internet of Things. Self-powered sensors (especially photovoltaic gas sensors) can solve these problems. In this study, for the first time, we report 2D TMDs (NbSe 2 -MoS 2 hybrid) on a SiO 2 /Si substrate to fabricate photovoltaic self-powered gas sensors. The gas sensors are operated by the photovoltaic effect of the NbSe 2 -MoS 2 nanostructure, which is prepared using the liquid phase exfoliation process. Initially, it was revealed that the present hybrid material exhibits photovoltaic properties under light illumination, with a circuit current of 0.25 µA and a circuit voltage of 34 mV. The NbSe 2 -MoS 2 nanostructure characteristics were then used for NH 3 gas sensing at different concentrations, and the gas sensing response was detected from low (8.8 % at 10 ppm) to high (28.8 % at 500 ppm) concentrations. The built-in electric field occurred between the NbSe 2 -MoS 2 junction and eventually operated as a driving force for NbSe 2 -MoS 2 gas sensing without an external bias voltage. The physisorption of gas molecules on their surface prompts a charge-transfer mechanism that improves the gas sensor response. The combined outcome of NbSe 2 -MoS 2 heterostructures could pave way to next-generation gas sensing device fabrications. [ABSTRACT FROM AUTHOR]

Background Toxocariasis, which is predominantly caused by Toxocara canis (T. canis) infection, is a common zoonotic parasitosis worldwide; however, the status of toxocariasis endemicity in the Republic of the Marshall Islands (RMI) remains unknown. Methods A seroepidemiological investigation was conducted among 166 primary school children (PSC) aged 7-12 years from the capital area of the RMI. Western blots based the excretory-secretory antigens of larval T. canis (TcES) was employed, and children were considered seropositive if their serum reacted with TcES when diluted at a titer of 1:64. Information regarding demographic characteristics of and environmental risk factors affecting these children was collected using a structured questionnaire. A logistic regression model was applied to conduct a multivariate analysis. Results The overall seropositive rate of T. canis infection was 86.75% (144/166). In the univariate analysis, PSC who exhibited a history of feeding dogs at home (OR = 5.52, 95% CI = 1.15-26.61, p = 0.02) and whose parents were employed as nonskilled workers (OR = 2.86, 95% CI = 1.08-7.60, p = 0.03) demonstrated a statistically elevated risk of contracting T. canis infections. Cleaning dog huts with gloves might prevent infection, but yielded nonsignificant effects. The multivariate analysis indicated that parental occupation was the critical risk factor in this study because its effect remained significant after adjusting for other variables; by contrast, the effect of dog feeding became nonsignificant because of other potential confounding factors. No associations were observed among gender, age, consuming raw meat or vegetables, drinking unboiled water, cleaning dog huts with gloves, or touching soil. Conclusions This is the first serological investigation of T. canis infection among PSC in the RMI. The high seroprevalence indicates the commonness of T. canis transmission and possible human risk. The fundamental information that the present study provides regarding T. canis epidemiology can facilitate developing strategies for disease prevention and control. [ABSTRACT FROM AUTHOR]