If we construct isosceles polygon Pa k with (k − 1) sides of the same length over each side of regular polygon Pb n , with n sides, we get a new equilateral polygon P a,δ N with N = (k− 1)n sides of the same length and with different inner angles. Such polygon is called equilateral semi-regular polygon. This paper deals with metric properties of general semi-regular polygons Pa N , with given s...

A 50 year old, hypertensive male presented in emergency department with complains of intermittent chest pain on exertion since 1 month. His clinical examination was unremarkable. Chest skiagram revealed a cardiothoracic ratio of 0.55. Electrocardiogram showed left ventricular hypertrophy with ‘ST’ depression of 2mm in anterior precordial leads (V1-V6). Finally coronary angiogram was done which ...

introduction: objective: this study aimed to assess the possible variations in root canal anatomy and topography of the apices of first and second maxillary molars. materials and methods: a total of 67 first and second maxillary permanent molars were collected. access cavity was prepared and 2% methylene blue was injected. the teeth were demineralized by 5% nitric acid and cleared with methyl s...

We present a comparison of three neural PCA techniques: the GHA by Sanger, the APEX by Kung and Diamataras, and the { APEX rst proposed by the present authors. Through numerical simulations and computational complexity evaluations we show the {APEX algorithms exhibit superior capability and interesting features.

petrous apex lesions of temporal bone progress slowly. most of the time not only destruct this area but also involve neighbouring element. the symptoms of the neighbouring neuro-vasculare involvement we can recognize these lesions. the most common symptoms of involvement of the petrous apex are: headache, conductive hearing loss or sensorineural type, paresthesia and anesthesia of the trigemina...

introduction: success in endodontic treatment depends on various factors. among the most important factors, appropriate preparation of the root canal system and keeping periapical region intact as much as possible could be mentioned. these are achieved by determining the penetration depth of the instruments into the canal i.e. the working length. several methods are introduced for working lengt...

introduction: the aim of this study was to gather information on the materials and methods employed in root canal treatment (rct) by general dental practitioners (gdps) in iran. methods and materials: a questionnaire was distributed among 450 dentists who attended the 53 th iranian dental association congress. participants were asked to consider demographic variables and answer the questions re...