background : the most frequent use of diatoms in forensic science is the diagnosis of death due to drowning. the basic principle of diatom test in drowning is based on the inference that diatoms are present in medium where drowning took place and the inhaled water enters the alveolar spaces of lungs and penetrates from the alveoli into the blood circulation, thus microscopic unicellular algae c...

introduction: this study aimed to assess the scanning electron microscope (sem) analysis of tooth surface irradiated by erbium:yttrium–aluminum–garnet (er:yag) laser with various parameters. methods: number of 25 extracted human third molars free of caries were used in this study. the teeth were put into 5 groups for laser irradiation as follows: group 1 (power: 0.5 w, energy: 50 mj); group 2 (...

introduction and objective: alport’s syndrome (hereditary nephritis with deafness) is a familial uncommon disease that ultra-structural studies are gold standard method of its diagnosis. materials and methods:we studied 26 iranian patients suspicious of alport’s syndrome by electron microscopy. we examined 19 men and 7 women (male to female ratio was 2.7) and the average age was 1.5 years (with...

background and objectives: biological scaffold resources composed of extracellular matrix (ecm) have been shown to make easy the practical remodeling of various tissues in both animal and human studies. the goal of current study was to make sheet form of ecm from sheep’s urinary bladder. methods: ecm was extracted from sheep’s urinary bladder according to standard method. scanning electron mic...

the normal and lateral line cycloid scales of the native species garra rossica (nikol’skii, 1900), one of the most common and poorly known cyprinid fish in south-eastern iran have been subjected to the scanning electron microscopy technique in order to study their detailed structure. normal scale below the dorsal fin showed a clearcut demonstration between the anterior and posterior region with...

the aim of the present study was to investigate the light and electron microscopic structure of the tongue in white-eared bulbul (pycnonotus leucotis). six adult white-eared bulbul (3 males and 3 females) in shahrekord district were used in the investigation. samples of the apex, body and root of the tongue were prepared routinely for light and electron microscopic study. results showed that th...

background cucumber mosaic virus (cmv) has isometric particles with a diameter of about 28–29 nm. a useful method to recognize regions from mutagenesis in the coat protein (cp) gene are important for particle assembly and the expression of viral in cp expression systems like bacteria such as e.coli or yeast as well as their assembly into virus-like particles (vlp). objectives in this paper, we ...

in this research, al-ni particle composite strips are formed by accumulative roll bonding (arb) process using al strips and ni powder. the rule of arb cycles and volume percentage (vol%) of ni powder on the microstructure, wear resistance and mechanical properties of the formed composites are investigated. according to the tensile test results, the yield stress and tensile strengths of the al -...

introduction: bacteria and their byproducts are major etiologic factors in endodontic diseases. prevention or reduction of root canal bacterial contamination is the main aim of endodontic treatment. the purpose of this in vitro study was to evaluate the effect of size and taper of master apical file (maf) in reducing bacteria from the apical third of the curved canals using a quantitative scann...

introduction: in this experimental study, the amount of smear layer (sl) remnants in curved root canals after chemomechanical instrumentation with two engine-driven systems or hand instrumentation was evaluated. methods and materials: forty-eight mesiobuccal roots of mandibular first molars with curvatures ranging between 25 and 35 degrees (according to schneider’s method) were divided into thr...