Effects of coating with different ceromers on the impact strength, transverse strength and elastic modulus of polymethyl methacrylate.

The aim of this study was to evaluate the mechanical properties of polymethyl methacrylate (PMMA) after coating with different ceromers. For transverse strength and modulus of elasticity tests, specimens of 65×10×2.5 mm dimensions were prepared (5 groups, n=10). For impact strength test, specimens of 60×7.5×4 mm dimensions were prepared (5 groups, n=10). Test group specimens were coated with one of four different types of ceromers, and specimens in the control group were not coated. After specimens were tested for transverse and impact strengths, the data were analyzed with Kruskal-Wallis and Conover post hoc tests (p<0.05). GLYMOTEOS-TiO2 and A174-TEOS significantly increased the transverse strength of PMMA. All ceromers caused a statistically significant increase in the elastic modulus of PMMA. While GLYMO-TEOS-ZrO2 significantly decreased the impact strength, the other ceromers did not cause any statistically significant difference in impact strength. Coating with ceromers substantially improved the mechanical properties of PMMA.

Effect of caffeic acid phenethyl ester on survival of axial pattern flaps in rats with ischaemia-reperfusion injuries.

Oxygen-derived free radicals have been implicated in the pathogenesis of tissue injury after ischaemia-reperfusion. Caffeic acid phenethyl ester (CAPE), an active ingredient of honeybee propolis, has been identified as having potent antioxidant and anti-inflammatory properties. We evaluated the ability of CAPE applied intraperitoneally in reducing tissue injury after ischaemia-reperfusion. To investigate whether treatment with CAPE modifies the concentrations of the endogenous indices of oxidant stress, we examined its effects on a model of flap ischaemia-reperfusion injury in rats. CAPE (10 micromol/kg) was given through the peritoneum before reperfusion. CAPE given intraperitoneally had an inhibitory effect on tissue injury after ischaemia-reperfusion comparable to that of a control group. The anti-inflammatory and antioxidant properties of CAPE may contribute to its suppression of tissue injury.

Apricot sulfurization: an occupation that induces an asthma-like syndrome in agricultural environments.

BACKGROUND: Several cases of bronchial asthma have been presenting with acute attacks during the seasons of apricot sulfurization. The aim of this study was to reveal the effects of sulfur dioxide (SO(2)) exposure on the airways of the workers involved in this process. METHODS: SO(2) levels in air were measured on 15 apricot farms, while the symptom scores of 69 workers were recorded before, during, and after SO(2) exposure. Physical examination and pulmonary function tests (PFT) of the workers were also done prior to and after exposure periods. RESULTS: The measured SO(2) concentrations ranged between 106.6 and 721.0 ppm. Dyspnea (80%), cough (78%), and eye and nose irritation (83-70%) were the most commonly observed symptoms. The workers had significant decreases in pulmonary functions after SO(2) exposure. Decrements in FEV(1), FEV(1)/FVC%, and FEF(25-75%) showed that the acute effect of SO(2) on pulmonary functions of the workers was mostly of obstructive pattern. CONCLUSIONS: Acute exposure to SO(2) induces "asthma-like syndrome" (ALS) in apricot sulfurization workers. SO(2) which has not been previously reported in agricultural environments as a cause of ALS may be considered as a new agent.