Optical and dielectric response of two-dimensional WX2 (X = Cl, O, S, Se, Te) monolayers: A comprehensive study based on density functional theory.

Here, we study the dielectric and optical properties of two-dimensional (2D) WX2 monolayers, where X is Cl, O, S, Se, and Te. First principle electronic band structure calculations reveal that all materials are direct band gap semiconductors except WO2 and WCl2 , which are found to be indirect band gap semiconducting 2D materials. The dielectric response of these materials is also systematically investigated. The obtained results suggest that these materials are suitable as dielectric materials to suppress unwanted signal noise. The optical properties of these 2D materials, such as absorption, reflection and extinction coefficients, refractive index, and optical conductivity, are also calculated from the dielectric function. It is found that these materials exhibit excellent optical response. The present electronic, dielectric, and optical findings indicate that WX2 monolayers have an opportunity in electronic, optical, and optoelectronic device applications.

Recent advances in ZnO nanostructure as a gas-sensing element for an acetone sensor: a short review.

Air pollution is a severe concern globally as it disturbs the health conditions of living beings and the environment because of the discharge of acetone molecules. Metal oxide semiconductor (MOS) nanomaterials are crucial for developing efficient sensors because of their outstanding chemical and physical properties, empowering the inclusive developments in gas sensor productivity. This review presents the ZnO nanostructure state of the art and notable growth, and their structural, morphological, electronic, optical, and acetone-sensing properties. The key parameters, such as response, gas detection limit, sensitivity, reproducibility, response and recovery time, selectivity, and stability of the acetone sensor, have been discussed. Furthermore, gas-sensing mechanism models based on MOS for acetone sensing are reported and discussed. Finally, future possibilities and challenges for MOS (ZnO)-based gas sensors for acetone detection have also been explored.

WS2 Nanorod as a Remarkable Acetone Sensor for Monitoring Work/Public Places.

Here, we report the synthesis of the WS2 nanorods (NRs) using an eco-friendly and facile hydrothermal method for an acetone-sensing application. This study explores the acetone gas-sensing characteristics of the WS2 nanorod sensor for 5, 10, and 15 ppm concentrations at 25 °C, 50 °C, 75 °C, and 100 °C. The WS2 nanorod sensor shows the highest sensitivity of 94.5% at 100 °C for the 15 ppm acetone concentration. The WS2 nanorod sensor also reveals the outstanding selectivity of acetone compared to other gases, such as ammonia, ethanol, acetaldehyde, methanol, and xylene at 100 °C with a 15 ppm concentration. The estimated selectivity coefficient indicates that the selectivity of the WS2 nanorod acetone sensor is 7.1, 4.5, 3.7, 2.9, and 2.0 times higher than xylene, acetaldehyde, ammonia, methanol, and ethanol, respectively. In addition, the WS2 nanorod sensor also divulges remarkable stability of 98.5% during the 20 days of study. Therefore, it is concluded that the WS2 nanorod can be an excellent nanomaterial for developing acetone sensors for monitoring work/public places.

Usefulness of combined handheld ultrasound and fluoroscopy-guided injection in adhesive capsulitis of the shoulder: A prospective, randomized single blind-pilot study.

BACKGROUND: Ultrasound is increasingly being utilized in the diagnosis and treatment of adhesive capsulitis. OBJECTIVE: To compare the therapeutic effects and advantages of combined handheld ultrasound and fluoroscopy-guided intra-articular corticosteroid injection with those of conventional ultrasound-guided corticosteroid injection in adhesive capsulitis of the shoulder. METHODS: A total of 39 patients diagnosed with adhesive capsulitis of the shoulder were randomly assigned into two groups. Group A patients (n= 19) underwent combined handheld ultrasound and fluoroscopy-guided corticosteroid injection and group B patients (n= 20) underwent conventional ultrasound-guided corticosteroid injection to the intra-articular space of the shoulder twice. Treatment efficacy was assessed at 2 and 6 weeks after the final injection, based on the verbal numeric pain scale, Shoulder Pain and Disability Index, and range of motion. Secondary outcome measures were the accuracy and procedure time. RESULTS: Both injection methods were effective in the treatment of adhesive capsulitis. No significant differences in treatment efficacy and injection accuracy were observed between the two groups (p> 0.05). CONCLUSIONS: This study showed no statistical differences in treatment efficacy between 2 groups. However, the combined use of ultrasound and fluoroscopy can increase the accuracy of injection compared with conventional ultrasound alone.