RESUMO
In this work, we consider a frustrated two-leg spin-1/2 ladder composed of Heisenberg ferromagnetic and antiferromagnetic spin-1/2 chains, and nearest spins from different legs interact via Heisenberg type rung exchange interactions that can be either ferromagnetic or antiferromagnetic in nature. The competing exchange interactions in the system lead to five different quantum phases like ferromagnetic, non-collinear ferrimagnetic (NCF), m - 1 / 4 ${m - 1/4}$ , antiferromagnetic and dimer phases. The quantum phase diagram is constructed for the Heisenberg spin-1/2 model and the phases are characterized using the correlation functions which are calculated by the density matrix renormalization group method. We also analyze the stability of m - 1 / 4 ${m - 1/4}$ phase and calculate the pitch angle θ ${\left( \theta \right)}$ in the NCF phase.
RESUMO
Recurrent apthous stomatitis (RAS) is one of the most common oral inflammatory diseases characterised by painful recurrent ulcerations of the orofacial region. The ulcers occur in three clinical forms: minor, major and herpetiform. Several therapies have been advocated to manage these lesions such as topical corticosteroids (triamcinolone acetonide, hydrocortisone acetate and clobetasol propionate), chlorhexidine mouth rinses, tetracycline oral rinses, thalidomide, fluocinonide, colchicines and the immune boosting agent levamosile, vitamin therapy and topical interferon α-2a. Laser therapy is used as an alternative method in treatment of RAS. In this paper one patient with RAS was treated using a 940 nm diode laser for symptomatic relief of pain and burning sensation and healing of ulcer.