Slabo izražene pojave u epr spektru paramagnetičnog centra sličnog šupljini u citozin hidrokloridu

The fine phenomena in the EPR spectra of the hole-like paramagnetic centre formed in cytosine(thiocytosine)-HCl crystals upon irradiation are studied with EPR spectroscopy. The spin Hamiltonian including the electronic Zeeman term, hyperfine coupling, quadrupole coupling and the nuclear Zeeman term has been used in the second-order perturbation treatment for the interpretation of the experimental observations. It is shown that the quadrupolar term causes a detectable shift of the EPR lines and also induces the "forbidden\u27\u27 transitions. From the shift of the "allowed\u27\u27 transitions and the positions of the ``forbidden\u27\u27 transitions, the chlorine quadrupolar coupling tensor [P], has been determined.Proučavane su slabo izražene, neredovite pojave u EPR spektrima paramagnetičnog centra sličnog šupljini u ozračenim kristalima citozin hidroklorida s primjesama tiocitozina. Za objašnjenje ponašanja upotrijebljen je spinski Hamiltonijan koji se sastoji od elektronskog Zeemanovog člana, nuklearnog Zeemanovog člana, člana hiperfine i člana kvadrupolne sprege jezgre s elektronom. Pokazano je da kvadrupolni član koji potječe od klora ne samo unosi pomak EPR spektralnih linija, nego uzrokuje i pojavu dodatnih, “zabranjenih” prijelaza. Iz mjerenja slabo izraženih pomaka linija i položaja “zabranjenih” linija izračunat je kvadrupolni tenzor

INDOOR AIR QUALITY IN A HIGH SCHOOL CLASSROOM IN RIJEKA, CROATIA (SICK CLASSROOMS CAUSED BY RISING CO2 LEVELS)

School’s indoor air quality (IAQ) is very important as it can affect student’s learning abilities and lead to health issues. Therefore, indoor air quality, and in particular the CO2 concentration, was monitored on a daily basis from mid-November till the end of December 2017, by using several low-cost instruments. The measuring was performed in the physics classroom of a grammar school in Rijeka, Croatia. Detailed CO2 generation rates, air exchange rates, and ventilation rates are calculated and reported in this work, from the experimentally obtained data. Very high concentrations of over 4.000 ppm were recorded, indicating that ventilation rates are far below 5 Ls-1 per person, which is the lowest recommended value of ventilation rate according to the European standard EN 13779. The experimentally obtained data are compared with the theoretical models and a strong correlation are achieved. This is one of the first comprehensive studies of this kind in Croatia; therefore, we hope that it will stimulate interest between health workers, scientists, and school management to implement indoor air quality monitoring practices and perhaps introduce automated ventilation systems in classrooms for the benefit of students’ health and their learning abilities

Epidemiological study on the incidence of haemorrhagic fever with renal syndrome in five Western Balkan countries for a 10-year period: 2006–2015

Background: Large-scale epidemics of haemorrhagic fever with renal syndrome (HFRS) have been reported mostly in Asia and Europe, with around 100,000 people affected each year. In the Southeast Europe, Balkan region, HFRS is endemic disease with approximately 100 cases per year. Our aim was to describe epidemiological characteristics of HFRS in five Western Balkan (WB) countries and to describe correlation between HFRS incidence and major meteorological event that hit the area in May 2014. Methods: National surveillance data of HFRS from Bosnia and Herzegovina, Croatia, Montenegro, North Macedonia and Serbia obtained from 1 January 2006 to 31 December 2015 were collected and analysed. Results: In a 10-year period, a total of 1,065 HFRS patients were reported in five WB countries. Cumulative incidence rate ranged from 0.05 to 15.80 per 100.000 inhabitants (in North Macedonia and Montenegro respectively). Increasing number of HFRS cases was reported with a peak incidence in three specific years (2008, 2012, and 2014). Average incidence for the entire area was higher in males than females (5.63 and 1.90 per 100.000 inhabitants respectively). Summer was the season with the highest number of cases and an average incidence rate of 1.74/100.000 inhabitants across 10-year period. Haemorrhagic fever with renal syndrome incidence was significantly increased (7.91/100.000 inhabitants) in 2014, when a few months earlier, severe floods affected several WB countries. A strong significant negative correlation (r = −.84, p < .01) between the monthly incidence of HFRS and the number of months after May's floods was demonstrated for the total area of WB. Conclusion: Our findings demonstrate that the HFRS incidence had similar distribution (general, age, sex and seasonality) across majority of the included countries. Summer was the season with the highest recorded incidence. Common epidemic years were detected in all observed countries as well as a negative correlation between the monthly incidence of HFRS and the number of months after May's cyclone