Thermoviscous dissipation of nonlinear acoustic waves in channels with wavy walls.

We derive a nonlinear acoustic wave propagation model for analyzing the thermoviscous dissipation of nonlinear acoustic waves in narrow pores with wavy walls using the boundary layer theory. As a nonlinear acoustic wave propagates in a pore, the wave-steepening effect competes with the bulk dissipation, as well as the thermoviscous heat transfer and shear from the pore walls. Due to thermoviscous dissipation, the wave thickness increases beyond the weak shock thickness scale.

Prenatal Diagnosis of Otocephaly: A Rare Facial Anomaly.

Introduction: Otocephaly is a rare malformation characterized by agnathia (absence of the mandible), melotia (medially displaced ear pinna), aglossia (absence of the tongue) and microstomia (small oral aperture). This results due to failure of migration of the neural crest cells and is a defect of the first branchial arch. It is incompatible with life and early prenatal diagnosis is useful.

Oral manifestations in COVID-19 patients: An observational study.

Background: Viral diseases continue to emerge as a threat to mankind and are a serious concern to public health. The latest lethal SARS-CoV-2 or COVID-19 is a highly contagious disease, which propagated quickly across the globe. Similar to other influenza-like viral infections, symptoms such as fever, dry cough, myalgia, arthralgia, headache, diarrhea, dyspnea, and fatigue were reported among COVID-19 patients.