learning vocabulary constitutes a crucial step in language learning. amongst different word categories, compound words have failed to attract the attention they deserve. this led us to conduct a study trying to pinpoint the difficulties learning these words and to suggest some techniques facilitating their acquisition. to that effect, a questionnaire as well as a vocabu-lary test were given to ...

benzalkonium chloride is a quaternary ammounium compounds derivative under different names such as afxhang, hamoon, mahan etc, which have great and expanded use in sanitation and medical affairs. bactericidal activity of these disinfectants was fulfilled according to national standard method no.2842 on staph. aureus, sal. typhimouium and e. coli. this laboratory test showed that, except mahan t...

background: several effects of volatile organic compounds (vocs) have been recognized such as toxic and carcinogenic human health effects. to evaluate cancer risk of benzenes air samples were taken, at an automobile manufacturing painters in tehran following inhalation exposure. methods: to perform this study, cross-sectional was done in 2016. sampling was carried out by active pump sampler usi...

halophilic bacteria grow over a wide range of salt concentrations. in this study we aimed to isolate and screen out the halophilic bacteria and to determine their activity for production of the bioactive compounds. a total of 50 water, sediments and soil samples were collected from maharlu salt lake in southern region of fars-iran and subjected for isolation of the bioactive compound producing ...

the term odontoma is used to identify a tumor that is characterized by the production of mature enamel, dentin, cementum and pulp tissue and may interfere with the eruption of the associated tooth. the present report describes an odontoma in a 13-year-old boy, which is associated with an impacted tooth through a canal

in this work, leather fibers were employed as a component of elastomeric compounds based on nbr, cr and epdm and studied were made on their effects upon curing characteristics and mechanical properties of the prepared compounds. evaluation of curing characteristics of the compounds demonstrated that leather fibers have no considerable effect on initial viscosity and curing time of the compounds...

nbo analysis and density functional theory (dft: b3lyp/6-311+g**) based method were used to study the impacts of the anomeric effects (ae) on the conformational properties of 2-methoxy-1,2,4,5-tetrahydro-benzo[d]oxepine (1), -thiepine (2) and -selenepine (3). the gibbs free energy difference (geq–gax) values (i.e. δgeq-ax) at 298.15 k and 1 atm between the axial and equatorial conformations inc...

introduction: in apical surgery, after apicoectomy and retro-preparation of canal, a retrofil material is applied to seal the apical region of the root canal. mineral trioxide aggregate (mta) is the gold standard material for this purpose. changing water/powder ratios of mta affects its properties. the purpose of this in vitro study was to determine the effect of liquid/powder ratio of retrofil...

results of total 60 s. aureus isolates, 51 (85%) were mrsa, and of 60 cons, 7 (11.66%) were mrcons. the results showed that the mic of chlorhexidine for all 120 isolates was 1-16 μg/ml. 15 (12.5%) isolates carried qaca/b gene, 26 (21.7%) carried qacc gene, and 38 (31.7%) carried smr gene. conclusions maintenance of mrsa isolates in the attendance of low amounts of antiseptics could result in th...