this study aimed to evaluate enamel roughness after adhesive removal using different burs and an er:yag laser.the buccal surfaces of forty human premolars were sealed by two layers of nail varnish, except for a circular area of 3 mm in diameter on the middle third. the enamel surfaces were initially subjected to profilometry analysis and four parameters of surface irregularity (ra, rq, rt and r...

objectives: scaling and root planing (srp) is one of the most commonly used procedures during periodontal treatment. the aim of this study was to evaluate the root surface roughness after srp with erbium: yttrium aluminum garnet (er:yag) laser compared to ultrasonic and hand instruments.   materials and methods: in this experimental study, 56 extracted sound single-rooted teeth with moderate le...

background and objectives: bacillus species are attractive industrial organisms due to their rapid growth rates leading to a short fermentation cycle and for their capacity to secrete important enzymes and proteins such as xylanase into the extracellular medium. considering the industrial importance of xylanase, in this current study, bacillus spp. were isolated from different soils and were sc...

in this work, all-solid-state potentiometric pvc membrane sensor was introduced for fast andsimple monitoring of mercury ions in waste water samples. the all solid sate electrode is made based on aconductive composite of graphite, reduced graphene oxide, epoxy resin on a copper wire. a thin layer pvcmembrane is then coated on the surface of the new conducting transducer. pvc membrane is compose...

a solid state fermentation method was developed for the production of citric acid from date pulp (obtained of date syrup production from the process) by aspergillus niger ptcc 5010. poor yield was obtained when potassium ferrocyanide treated date pulp were used as substrate, but methanol at a 3-4% concentration markedly increased the forma-tion of citric acid from the waste. the optimum range o...

production of thermostable alkaline protease in tray bioreactor for solid state fermentation is a unique process which may lead to an economical approach for production of enzyme from agricultural waste or low cost substrate. in solid state fermentation using tray bioreactor, several agricultural residues such as rice bran, sugarcane bagasse, wheat bran, barely bran, corn meal and corn husk wer...

introdouction: dentinal hypersensitivity (dh) is one of the most painful chronic problems reported in dental offices. various methods have been applied for the treatment of dh. however, majority of them are either ineffective or last for a short period of time. it has been reported that lasers, particularly neodymium- doped: yttrium aluminum garnet laser (nd: yag), can be helpful in the treatme...

background: a substantial part of the public’s natural radiation dose is due to the inhalation of radon gas. most of the exposure occurs indoors where the airborne concentration of radon and its decay products is usually higher than outdoors. materials and methods: radon activity concentration has been measured twice in 50 classrooms in 5 levels (10 each) during summer and winter using solid-st...

caco3 nanoparticles have been synthesized via heat-treatment of a new precursor and solid state reaction. effect of calcinations temperature and quantity of surfactant on particle size has been investigated. the products were characterized by x-ray diffraction (xrd), scanning electron microscopy (sem), transmission electron microscopy (tem) and fourier transform infrared (ft–ir) spectroscopy.