Does atrial fibrillation affect plasma endothelin level?

Background: Atrial fibrillation (AF) may result in endocardial endothelium dysfunction. The main objective of the study was to evaluate the plasma concentration of endothelin-1 (ET-1) during persistent AF and after sinus rhythm recovery following direct-current cardioversion and to assess the predictive value of ET-1 in AF patients. Methods: The study group consisted of 43 patients with persistent AF and normal left ventricle systolic function who had undergone successful cardioversion. Blood samples were collected twice: 24 hours before and 24 hours after cardioversion. All patients were also examined in terms of sinus rhythm maintenance on the 30th day after cardioversion. Results: There were no differences in ET-1 plasma concentration between the persistent AF group and the control group (2.6 ± 2.9 fmol/mL vs 2.3 ± 4.5 fmol/mL, NS). Plasma ET-1 levels did not change within 24 hours after successful cardioversion (2.5 ± 2.8 fmol/mL vs 2.6 ± 2.9 fmol/mL, NS). There was no correlation between the baseline plasma levels of ET-1 in patients with persistent AF and sinus rhythm maintenance 30 days after cardioversion. Conclusions: Persistent AF does not affect plasma ET-1 concentration in patients with normal left ventricle systolic function and with no symptoms of heart failure. There are no significant changes in plasma ET-1 level during the 24 hours after cardioversion. (Cardiol J 2010; 17, 5: 471-476

Properties and performance of mesoporous activated carbons from scrap tyres, bituminous wastes and coal

Tyre wastes and their blends with coal and a bituminous waste material obtained from the benzol distillation column of a by-product section of a coking plant were employed as a precursor for the production of activated carbons (ACs). Pyrolysis up to 850 °C followed by physical activation with CO2 produced mesoporous carbons with different pore size distributions and surface areas. The surface chemistry of the samples was studied by measuring the point of zero charge (pHpzc) and by temperature programmed desorption (TPD). The activated carbons obtained contained higher amounts of basic functional groups. Their textural and surface chemistry characteristics make them highly suitable for adsorbing anionic dyes of large molecular size, such as Congo red. The adsorption kinetics was found to conform closely to the pseudo-second-order kinetic model. To determine the adsorption mechanism, the kinetic data were also analyzed using the Weber and Morris intraparticle diffusion model and the Boyd model to distinguish between the pore and film diffusion steps. The equilibrium isotherms were of the Langmuir isotherm type. The efficiency of the low-cost ACs prepared for the removal of Congo red dye was similar to that reported in the literature for coal-based ACs and greater than that of other low-cost ACs

Development of business tourism in Cracow

Przedmiotem niniejszej pracy są perspektywy rozwoju turystyki biznesowej wKrakowie. Celem pracy była analiza zasobów krakowskiej infrastruktury biznesowej,określenie największych problemów miasta w kwestii organizacji przemysłu spotkań orazocena jakości świadczonych usług w krakowskich obiektach szkoleniowo – konferencyjnych.Turystyka biznesowa jest generującym najwyższe dochody i jednym z najszybciejrozwijających się segmentów turystyki. Także i władze Krakowa, miasta doświadczonego wobsłudze turystów, próbują wspierać w swych działaniach firmy organizujące spotkaniabiznesowe, szczególnie te o dużej randze, gdyż wpływają one pozytywnie na prestiż samegomiasta. Podstawowymi źródłami danych były raporty Polskiej Organizacji Turystyki, pozycjeksiążkowe, źródła Internetowe oraz badania własne przeprowadzone wśród tzw. turystówbiznesowych, przebywających w Krakowie w podróży służbowej.The main issue of MA thesis is development of Cracow’s business tourism. The mainpurpose is an analysis of business infrastructure in Cracow, indication of vital problems andestimation quality of Cracow’s hotels service . Business tourism means every kind of activityconected with work. Nowadays, this segment of tourism, becomes more and more popular,especially in big cities, like Cracow, so that’s why te goverment of town tries to do its best, toimprove development possibilities. The MA thesis based on database reports, articles frombusiness press, science and elektronic publications

Recent Studies on the Development of Nicotine Abuse and Behavioral Changes Induced by Chronic Stress Depending on Gender

Nowadays, stressful situations are an unavoidable element of everyday life. Stressors activate a number of complex mental and physiological reactions in the organism, thus affecting the state of health of an individual. Stress is the main risk factor in the development of mental disorders, such as depression and other disorders developing as a result of addiction. Studies indicate that women are twice as likely as men to develop anxiety, depression and therefore addiction, e.g., to nicotine. Even though the data presented is indicative of significant differences between the sexes in the prevalence of these disorders, the majority of preclinical animal models for investigating stress-induced disorders use predominantly male subjects. However, the recent data indicates that this type of studies has also been launched in female rodents. Therefore, conducting research on both sexes allows for a more accurate understanding and assessment of the impact of stress on stress-induced behavioral, peripheral and molecular changes in the body and brain. In this manuscript we have gathered the data from 41 years (from 1981–2022) on the influence of stress on the development of depression and nicotine addiction in both sexes