Different distribution of CD4 and CD8 T cells in synovial membrane and peripheral blood of rheumatoid arthritis and osteoarthritis patients.

Rheumatoid arthritis (RA) and osteoarthritis (OA) are chronic diseases associated with morphological joint changes. Synovial membrane (SM) involvement was established for RA, but the data for OA are limited, because OA is usually regarded as noninflammatory disease. Changes in immune system in RA are not limited to joints, and the significant role of T cells of peripheral blood (PB) is not disputable. However, there is still an open debate about PB immunological profile in OA. Therefore, we decided to measure the distribution of CD4+ and CD8+ T cells, regarding CD28 expression, both in PB and SM of RA and OA patients, on the same day. Altogether, eleven RA patients, 11 OA patients and similar numbers of age-matched healthy controls were included into the study. Flow cytometry was used for T cells subpopulation distinguishing and quantification; monoclonal antibodies against CD3, CD4, CD8 and CD28 with different fluorochromes were used for stainings. The RA patients had significantly higher percentage of CD3+4+ cells in PB as compared to OA patients and relevant control group. Both within the CD4+ and CD8+ compartments, significantly lower percentages of cells bearing the CD28 marker were found in the PB of OA as compared to RA patients. The proportion of CD3+CD4+ cells in SM was dependent on age of OA patients, older OA patients had significantly higher value of their SM/blood ratio than RA patients. Older OA subjects were also characterized by higher values of the SM/blood ratio of both CD4+CD28+ and CD8+CD28+ subpopulations than RA or younger OA patients. In conclusion, in contrast to the traditional view of OA disease, our results give support to the hypothesis that OA may also (like RA) be a disease with a local immunological involvement

Verification of Baffle Factor for Straight Pipe Flow

The baffle factor is a parameter widely used to describe flow system characteristics. This indicator is very important in designing disinfection devices. For example, it is used to convert the plug flowtime to the actual fluid residence time in the flowsystem of interest. Its accurate determination is a complex problem requiring tracer experiments or computational fluid dynamics simulations. Therefore, in practice, it is often taken from tables provided in the literature. The literature sources, however, state that the baffle factor for a flow in a straight pipe is equal to unity, which implies the identity between the pipe flow model and the plug flow model. This assumption is doubtful. The aim of the present work is to verify the baffle factor values assumed for the pipe flow. The merit of this study is the analytical derivation of the expression describing the baffle factor value with respect to flow characteristics. To this purpose, the analytical solution of a one-dimensional advection-diffusion equation with a Heaviside initial condition was used. It was demonstrated that the aforementioned assumption is wrong, as the baffle factor for a straight pipe is significantly less than unity

Thermal disintegration as a process supporting sewage sludge utilization

Highly effective methods of biological and chemical wastewater treatment applied in Poland resulted in an increased amount of generated sewage sludge, which pose serious problem related to its utilization. The purpose of this studies was to determine the impact of the thermal disintegration process (in low temperatures 70%) already at a temperature of 45°C. At the same time, the concentration of volatile fatty acids (VFAs) increases more than 55 times, which can significantly shorten the fermentation process