Raman Spectra and Excitonic Effects of the Novel TaNiTe Monolayer.

We have investigated the Raman spectrum and excitonic effects of the novel 2D TaNiTe structure. The monolayer is an indirect band gap semiconductor with an electronic band gap value of 0.09 and 0.

Electronic, Excitonic, and Optical Properties of Zinc Blende Boron Arsenide Tuned by Hydrostatic Pressure.

Based on first-principles calculations combined with a maximally localized Wannier function tight-binding method and the Bethe-Salpeter equation formalism, we theoretically investigate the effects of hydrostatic pressure on the electronic, excitonic, and optical properties of zinc blende boron arsenide. Our findings show: (i) a pressure-induced semiconductor-to-metallic phase transition without causing any change in the structural crystallographic ordering, (ii) a decrease in excitonic binding energy with increasing pressure as a consequence of band gap engineering, and (iii) a small excitonic response in the indirect absorption regime due to the indirect band gap.

Investigating Molecular Adsorption on Graphene-Supported Platinum Subnanoclusters: Insights from DFT + D3 Calculations.

Platinum (Pt) subnanoclusters have become pivotal in nanocatalysis, yet their molecular adsorption mechanisms, particularly on supported versus unsupported systems, remain poorly understood. Our study employs detailed density functional theory (DFT) calculations with D3 corrections to investigate molecular adsorption on Pt subnanoclusters, focusing on CO, NO, N, and O species. Gas-phase and graphene-supported scenarios are systematically characterized to elucidate adsorption mechanisms and catalytic potential.

Stability and Optoelectronic Properties of Two-Dimensional Gallium Phosphide.

Using first-principles calculations, density functional theory, and the tight-binding method, we investigate the optoelectronic properties of two-dimensional gallium phosphide (2D GaP). Our investigation covers electronic properties, such as band structure and electronic band gap, and optical properties, including absorption spectra, refractive index, and reflectivity, considering excitonic effects. Additionally, structural aspects such as stability, elastic properties, and Raman and infrared spectra are also analyzed.

Tuning Excitonic Properties of Monochalcogenides via Design of Janus Structures.

Two-dimensional (2D) Janus structures offer a unique range of properties as a result of their symmetry breaking, resulting from the distinct chemical composition on each side of the monolayers. Here, we report a theoretical investigation of 2D Janus ''31 monochalcogenides from group IV ( and ' = Ge and Sn; , ' = S and Se) and 2D non-Janus 3̅1 counterparts. Our theoretical framework is based on density functional theory calculations combined with maximally localized Wannier functions and tight-binding parametrization to evaluate the excitonic properties.

Contrasting the stability, octahedral distortions, and optoelectronic properties of 3D MABX and 2D (BA)(MA)BX (B = Ge, Sn, Pb; X = Cl, Br, I) perovskites.

Efficient surface passivation and toxic lead (Pb) are known obstacles to the photovoltaic application of perovskite-based solar cells. A possible solution for these problems is to use thin-films of two-dimensional (2D) perovskite-based materials and the replacement of Pb with alternative divalent cations (B); however, our atomistic understanding of the differences between (3D) three-dimensional and 2D perovskite-based materials is far from satisfactory. Herein, we report a systematic theoretical investigation based on density functional theory (DFT) calculations for both 3D MABX and the Ruddlesden-Popper 2D (BA)(MA)BX (B = Ge, Sn, Pb, and X = Cl, Br, I) compounds to investigate the differences (contrasts) in selected physical-chemical properties, , structural parameters, energetic stability, electronic, and optical properties.

Promising TMDC-like optical and excitonic properties of the TiBr 2H monolayer.

The presented simulation protocol provides a solid foundation for exploring two-dimensional materials. Taking the TiBr 2H monolayer as an example, this material displays promising TMDC-like optical and excitonic properties, making it an excellent candidate for optoelectronic and valleytronic applications. The direct band gap semiconductor (1.

Unveiling oxygen vacancy impact on lizardite thermo and mechanical properties.

Here, we performed a systematic DFT study assisted by the workflow framework SimStack for the mechanical and thermodynamic properties of the clay mineral lizardite in pristine and six different types of O vacancies configurations. In most cases, the defect caused a structural phase transition in the lizardite from the trigonal (pristine) to the triclinic phase. The results show that oxygen vacancies in lizardite significantly reduce the lattice thermal conductivity, accompanied by an elastic moduli reduction and an anisotropy index increase.

Poisoning by Brunfelsia uniflora in sheep and donkeys.

Farmers in the State of Piauí in northeastern Brazil reported nervous signs in ruminants and donkeys after ingestion of Brunfelsia uniflora at the start of the rainy season when the plant is flowering. Leaves of the plant, collected at the start or at the end of the rainy season, were administered in single doses of 5-20 g/kg body weight to 8 sheep and 3 donkeys. Two sheep and 1 donkey that ingested 10 g/kg of the plant in November at the start of the rainy season, when the plant was flowering, developed severe convulsions and diarrhea.

Diabetes-Related Cognitive Decline, a Global Health Issue, and New Treatments Approaches.

The epidemic of type 2 diabetes (T2DM) is spreading around the globe and challenging the unprecedented success of health sciences in increasing longevity. T2DM has been linked to accelerated brain aging, functional decline in older adults and dementia. Brain insulin resistance and glycemic variability are potential mechanisms underlying T2DM-related brain damage and cognitive decline.