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• Janus Al 2 SSe monolayer is dynamically and thermally stable at room temperature. • Al 2 SSe monolayer is an indirect semiconductor with band gap of 2.079 eV. • Electronic properties of Al2SSe monolayer depend strongly on biaxial strain. • Al 2 SSe monolayers can strongly absorb the near-ultraviolet light. • Optical absorbance intensity of Al2SSe can be enhanced by strain. Motivated by the successful experimental fabrication of Janus structures recently, a systematic study of the structural, electronic, and optical properties of the Janus Al 2 SSe monolayer has been done through first-principles approach. Through phonon spectrum and ab initio molecular dynamics analysis, Al 2 SSe was confirmed to be dynamically and thermally stable. The Janus Al 2 SSe monolayer exhibits a semiconducting characteristics with indirect band gap of 2.079 eV at equilibrium. While biaxial strain can significantly alter band gap, the influence of electric field on electronic as well as optical properties is negligible. The optical absorbance of Al 2 SSe is activated in the visible light region and its intensity can be enhanced by strain. Our findings only highlight the physical properties but also provide an effective way for tuning the electronic and optical properties of Al 2 SSe monolayer by strain engineering. [ABSTRACT FROM AUTHOR]

In line with ongoing efforts on discovering new materials for the utilization in advanced nanotechnologies, in the present work, based on the original Fe 3 GeTe 2 material, two-dimensional Janus Fe 3 Ge X Te (X = S and Se) monolayers are constructed and analyzed by using first-principles calculations. All three monolayers of Fe 3 GeTe 2 , Fe 3 GeSTe, and Fe 3 GeSeTe exhibit hexagonal structures with good dynamical stability. No negative frequency is observed in the phonon dispersion spectra. During the ab initio molecular dynamics simulation at room temperature, the Fe 3 Ge X Te structures are predicted to be thermally stable without any reconstruction/fracture, suggesting the high thermal stability of these systems. In addition, the Fe 3 Ge X Te monolayers show high negative cohesive energy of about − 5 eV/atom and the obtained elastic constants satisfy the Born and Huang condition. Their Young's modulus and Poisson's ratio exhibit isotropic elastic behaviors due to the isotropic structures. These results confirm that the Fe 3 Ge X Te monolayers are energetically and mechanically stable for experimental synthesis. Especially, the electronic properties of our studied structures are explored for applications in electronic devices. The Fe 3 Ge X Te monolayers show a metallic nature for both the spin-up and spin-down cases. The projected density of states reveals that the Fe 3 GeTe 2 , Fe 3 GeSTe, and Fe 3 GeSeTe are magnetic materials due to their different spin-up and-down configurations. The results of our study can provide more information for the Janus Fe 3 Ge X Te materials and stimulate future experimental studies for practical applications in magnetic and electronic devices. [ABSTRACT FROM AUTHOR]

Abstract: Indentation models for thin layer-substrate geometry with an interphase have been developed. The interphase can be modeled either as a nonhomogeneous layer or as a homogeneous layer. Between the two models of the interphase, contact depth and critical interfacial stresses are compared to find the effect of indentation area, film and substrate Young’s moduli, and the interphase and film thicknesses. Although contact depth is found not to be sensitive to the type of interphase model used, critical interfacial stresses are significantly different (up to 15%) for film to substrate elastic Young’s moduli ratios of more than 25. A formal sensitivity analysis based on design of experiments shows that on critical interfacial stresses, interphase to film thickness ratio and film to substrate Young’s moduli ratio has the most impact, while type of elastic moduli variation in the interphase and indentor width to film thickness ratio has the least impact. [Copyright &y& Elsevier]

Sjögren's syndrome (SjS) is an autoimmune disease with a strong genetic association. To date, no vaccine or therapeutic agent exists to cure SjS, and patients must rely on lifelong therapies to treat symptoms. Human leukocyte antigens (HLA) are primary susceptibility loci that form the genetic basis for many autoimmune diseases, including SjS. In this study, we sought to determine whether blocking MHC class II I Ag7 antigen presentation in the NOD mouse would alleviate SjS by preventing the recognition of autoantigens by pathogenic T cells. Mapping of the antigenic epitopes of Ro60 autoantigen to I Ag7 of the NOD mice was performed using structural modeling and in-vitro stimulation. Tetraazatricyclo-dodecane (TATD) and 8-Azaguanine (8-Aza) were previously identified as potential binders to I Ag7 of the NOD mice using in silico drug screening. Mice were treated with 20mgs/kg via IP every day five days/week for 23 weeks. Disease profiling was conducted. Specific peptides of Ro60 autoantigen were identified to bind to I Ag7 and stimulated splenocytes of the NOD mice. Treating NOD mice with TATD or 8-Azaguanine alleviated SjS symptoms by improving salivary and lacrimal gland secretory function, decreasing the levels of autoantibodies, and reducing the severity of lymphocytic infiltration in the salivary and lacrimal glands. This study presents a novel therapeutic approach for SjS by identifying small molecules capable of inhibiting T cell response via antigen-specific presentation. CQN is supported financially in part by PHS grants AI130561, DE026450, and DE028544 from the National Institutes of Health. [ABSTRACT FROM AUTHOR]