Wear Resistance of the Glass-Fiber Reinforced Polymer Composite with the Addition of Quartz Filler.

The paper presents the results of investigations on the glass fiber reinforced composite for the floor panels with quartz powder additions of different percentages in terms of wear resistance, friction coefficient, hardness, and strength. The wear resistance was assessed using the specific wear work parameter determined by the novel tribotester with friction band. It was found that an increase in quartz powder addition to the tested polymer composite does not enhance its mechanical increasingly properties. From the wear tests it can be concluded that only the composite with four layers of glass fibers and 6 wt.% of the quartz powder exhibited improvement of the wear resistance, but its shear strength was lower than that of the two layer specimens with similar powder proportions. On the other hand, the highest friction coefficient's, which is microhardness HV05, shear strength and impact strength were attained for the composite with two layers of glass fibers and 3 wt.% of the quartz powder. Among four layer samples, very close results were obtained for the samples with 10% of powder and insignificantly lower strength were observed for the samples with no powder added. The results revealed that there is no clear trend for the effect of silica filler percentage on the composite performance, which indicates the need for individual purpose-dependent decision making in the design of the glass fiber reinforced composites with quartz powder filler.

Acute hypersensitivity pneumonitis in woodworkers caused by inhalation of birch dust contaminated with Pantoea agglomerans and Microbacterium barkeri.

CASE DESCRIPTION: Five workers (2 males and 3 females) employed in a furniture factory located in eastern Poland developed hypersensitivity pneumonitis (HP) after the pine wood used for furniture production was replaced by birch wood. All of them reported onset of respiratory and general symptoms (cough, shortness of breath, general malaise) after inhalation exposure to birch dust, showed crackles at auscultation, ground-glass attenuations in HRCT examination, and lymphocytosis in the BAL examination. The diagnosis of acute HP was set in 4 persons and the diagnosis of subacute HP in one. IDENTIFICATION OF SPECIFIC ALLERGEN: Samples of birch wood associated with evoking disease symptoms were subjected to microbiological analysis with the conventional and molecular methods. Two bacterial isolates were found to occur in large quantities (of the order 108 CFU/g) in examined samples: Gram-negative bacterium of the species Pantoea agglomerans and a non-filamentous Gram-positive actinobacterium of the species Microbacterium barkeri. In the test for inhibition of leukocyte migration, 4 out of 5 examined patients showed a positive reaction in the presence of P. agglomerans and 2 in the presence of M. barkeri. Only one person showed the presence of precipitins to P. agglomerans and none to M. barkeri. In the inhalation challenge, which is the most relevant allergological test in the HP diagnostics, all patients reacted positively to P. agglomerans and only one to M. barkeri. The results indicate that P. agglomerans developing in birch wood was the main agent causing HP in the workers exposed to the inhalation of dust from this wood, while the etiologic role of M. barkeri is probably secondary. CONCLUSION: The results demonstrate that apart from fungi and filamentous actinobacteria, regarded until recently as causative agents of HP in woodworkers, Gram-negative bacteria and non-filamentous actinobacteria may also elicit disease symptoms in the workers processing wood infected with large amounts of these microorganisms. The results obtained also seem to indicate that cellular-mediated reactions are more significant for causing disease symptoms compared to those that are precipitin-mediated.

Thiram - Toxic inhalational lung injury.

INTRODUCTION: Thiram, a fungicides, is widely used on seeds and as foliar agent on turf, vegetables and fruit. It is also used in the rubber industry as a vulcanization accelerator. When absorbed through the respiratory system, it is rapidly metabolised to dimethylthiocarbamate and carbon disulphide, causing noxious effects. A brief review is presented of the literature, centering on the interesting case of a 45-year-old woman admitted to the hospital suffering from acute respiratory failure. RESULTS: Computer tomography in angiographic option (angio-CT) showed an extensive, irregular area of ground glass in both upper lobes and apical segments of the lower lobes of the lungs. A significant enlargement of both atria was also described. There was no improvement after cardiac treatment and patient was transferred to the pulmonary department where she was succesfully treated with systemic glucocortycosteroids. The patient remains under the supervision of the pulmonary out-patient department.

Total anomalous pulmonary vein drainage in a 60-year-old woman diagnosed in an ECG-gated multidetector computed tomography - a case report and review of literature.

PURPOSE: Total anomalous pulmonary vein drainage (TAPVD) is a congenital cardiac defect in which there is no connection between pulmonary veins and the left atrium. Pulmonary veins form a confluence independent of the left atrium and drain to a systemic vein. TAPVD types are: supracardiac, cardiac, infracardiac, and mixed. TAPVD accounts for approximately 1.5-2.2% of all congenital heart diseases. This anomaly is usually diagnosed in the neonatal period, and it coexists with atrial septal defect. Adult cases of TAPVD are rarely reported. CASE REPORT: We report a rare case of a 60-year-old woman with incidentally found, uncorrected TAPVD in ECG-gated multidetector computed tomography. In previous echocardiographic examinations partial anomalous pulmonary venous return and atrial septal defect were diagnosed. CONCLUSIONS: ECG-gated multidetector computed tomography is a valuable diagnostic method for adults with congenital heart disease. It enables evaluation of coronary arteries and simultaneously provides detailed anatomy of great vessels.

The evaluation of mechanical properties of animal tendons after corticosteroid therapy.

The purpose of the study was to examine the effect of systemic glucocorticosteroids administration on mechanical properties of animal tendons. Twenty female Wistar rats were divided into two groups and those that formed experimental group were subjected activity of hydrocortisone given to the peritoneum. Mechanical tests were performed. Hydrocortisone administration caused reduction of force value and the increase of strain, also the value of elasticity module was significantly smaller comparing to the control group. The results of biomechanical tests suggested that glucocorticoids produce less stiffness tendon, which fails in maximum point of load. This study revealed that systemic hydrocortisone administration changes significantly mechanical properties of tendons, which may cause frequent failure of the tendon.