objective: this in vitro study evaluated the fracture strength and bending amount of twotypes of fiber reinforced composite (frc) and cast metal frameworks used for fabrication of inlay fixed partial dentures (ifpds). materials and methods: seventy-two extracted first maxillary premolars and molars (36 each) were embedded in acrylic resin to represent a missing of second maxillary premolar. frc...

in this work poly eriochrome black t (ebt) was electrochemically synthesized on the glassy carbon electrode as electrode modifier. on the modified electrode, voltammetric behavior of isoniazid (inh) was investigated. the poly (ebt)-modified glassy carbon electrode has excellent electrocatalytic ability for the electrooxidation of isoniazid. this fact was appeared as a reduced overpotential of i...

the degradation of poly (vinyl pyrrolidone) (pvp) by means of ultrasound irradiation and itscombination with heterogenous photocatalysis (tio2 nanoparticles) was investigated. emphasiswas given on the effect of additive on degradation rate constants. 24 khz of ultrasoundirradiation was provided by a sonicator, while an ultraviolet source of 30 w was used for uvirradiation. to increase the effic...

plastics are well-established for convenient and safe packaging and distribution of food and feed goods. at present, this special sector of the plastic market displays remarkably increasing quantities of its annual production. caused by the ongoing limitation and strongly fluctuating prices of fossil feedstocks, classically used for plastic production, there is an evident trend to switch toward...

one-pot preparation of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles has been conducted in the presence of poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate, p(4vpbsa)hso4, as an efficient dual acidic catalyst under solvent-free conditions. reusability of the catalyst, easy work-up procedure, eco-friendly reaction conditions, short reaction times and high yields of th...

the taguchi design of experiments was used to test the relative importance of medium components and environmental factors on poly(β-hydroxybutyrate)(phb) production by ralstonia eutropha. the optimum condition was obtained as: fructose concentration, 15 g/l; c/n ratio, 7.4; agitation speed 200 rpm; culture time, 40 h; temperature, 25 ° c; seed age, 15 h. at optimum condition the yield of phb pr...

two poly(oxyethylene) derivatives 1.10-bis(2'-benzoic acid)-1,4,7,1-tetradecane (l1) and 1,7-bis(2'-benzoic acid)-1,4,7-trioxaheptane (l2) were used as suitable ionophores for the preparation of potassium-selective pvc-membrane electrodes. the resulting electrodes based on l1 and l2 exhibit linear responses to the activity of k+ ions within the concentration ranges of 3.1´10-5 -2.7´10-2 m and 2...

objective: tissue engineering is an (interdisciplinary field that applies polymeric scaffolds to control tissue formation in three-dinemtion (3d). the scaffold provides the microenvironment (synthetic temporary extracellular matrix) for regenerative cells, supporting cell attachment, proliferation, differentiation, and neo tissue genesis due to their suitable chemical, physical and biological s...

objective: nowadays, as the field of neural tissue engineering advances, the fabrication and application of combined structures open a new window of research for the regeneration of nervous system injuries. in this study, chitosan/poly(vinyl alcohol)-carbon nanotube nanocomposites has been exploited as scaffolds. materials and methods: electrospinning was used to fabricate chitosan/poly(vinyl ...

Single crystals of biodegradable aliphatic polyesters, poly([R]-3-hydroxybutyrate), poly([R]-3-hydroxyvalerate), poly(L-lactic acid), poly( -propiolactone), poly(4-hydroxybutyrate), poly(Æ-valerolactone), poly("caprolactone), poly(ethylene succinate) and poly(tetramethylene adipate), were grown from dilute solution by isothermal crystallization, and the crystal structures and morphologies were ...