Studies of discrete symmetries in decays of positronium atoms

A positronium - a bound state of electron and positron - is an eigenstate of parity and charge conjugation operators which decays into photons. It is a unique laboratory to study discrete symmetries whose precision is limited, in principle, by the effects due to the weak interactions expected at the level of 10−14 and photon-photon interactions expected at the level of 10−9. The Jagiellonian Positron Emission Tomograph (J-PET) is a detector for medical imaging as well as for physics studies involving detection of electronpositron annihilation into photons. The physics case covers the areas of discrete symmetries studies and genuine multipartite entanglement. The J-PET detector has high angular and time resolution and allows for determination of spin of the positronium and the momenta and polarization vectors of annihilation quanta. In this article, we present the potential of the J-PET system for studies of discrete symmetries in decays of positronium atoms

Prevalence of home mechanical ventilation in Poland

Wstęp: Domowe wspomaganie wentylacji (DWW) staje się coraz powszechniejszą metodą leczenia chorych z przewlekłą niewydolnością oddychania. Na jej rozwój wpływa starzenie się społeczeństwa, rozwój technologii umożliwiających stosowanie wentylacji w domu oraz stale poszerzający się zakres wskazań. Autorzy podjęli próbę oceny rozpowszechnienia DWW w Polsce, metod oraz wskazań do jej stosowania. Materiał i metody: Do wszystkich ośrodków prowadzących DWW oraz do wszystkich wojewódzkich oddziałów NFZ wysłano ankiety, w których proszono o udzielenie informacji na temat stosowania DWW. Wyniki: Na podstawie uzyskanych odpowiedzi ze wszystkich oddziałów NFZ ustalono, że na przełomie roku 2008/2009 w Polsce leczenie DWW stosowano u 846 chorych, w tym 31% dzieci, czyli u średnio 2,2 pacjenta na 100 tys. mieszkańców. Na ankiety odpowiedziało tylko 12 ośrodków (31%) prowadzących DWW. Zgłosiły one łącznie 206 leczonych chorych (24% wszystkich leczonych), z tego 122 (59%) było leczonych w sposób inwazyjny przez tracheostomię. Na schorzenia nerwowo-mięśniowe cierpiało 168 chorych (82%), pozostałych 38 (18%) na choroby układu oddechowego. Najczęstszymi przyczynami stosowania DWW była dystrofia mięśniowa (57 chorych, co stanowiło 34% pacjentów z chorobami nerwowo-mięśniowymi) i stwardnienie zanikowe boczne (39, 23%). Wśród chorób płuc i klatki piersiowej przeważali chorzy z POChP (17 pacjentów) oraz kifoskoliozą (10 chorych). Wnioski: Mimo znacznego rozwoju DWW w Polsce w ciągu ostatnich 10 lat, rozpowszechnienie tej metody leczenia nadal odbiega od stanu w innych krajach europejskich. Przyczyną tych różnic może być bardzo mała liczba pacjentów z chorobami układu oddechowego leczonych DWW. Wysoki odsetek chorych stanowią pacjenci leczeni w sposób inwazyjny. Głównymi przyczynami hamującymi rozwój DWW jest system kwalifikacji, który pomija udział specjalisty chorób płuc, brak ustalonych przez towarzystwa naukowe wskazań, wyjątkowo wymagające kryteria udzielania tego świadczenia nałożone przez NFZ oraz mała świadomość pulmonologów na temat potrzeby i możliwości leczenia tą metodą, zwłaszcza pacjentów z chorobami restrykcyjnymi układu oddechowego oraz zespołem hipowentylacji w przebiegu otyłości. Pneumonol. Alergol. Pol. 2010; 78, 6: 392-398Introduction: Home mechanical ventilation (HMV) is increasingly used in the treatment of chronic respiratory failure thanks to rapid technological development, increasing number of elderly people and extension of indications. The aim of the study was to assess: prevalence of HMV in Poland, the proportions of lung disease and neuromuscular patients using HMV and the type of interface (invasive v. non-invasive). Material and methods: The questionnaire was send to all institutions providing HMV in Poland and to regional departments of National Health System (NHS). Results: All NHS departments responded. They reported 846 HMV users, 31% of children. The prevalence of HMV in Poland was assessed as 2,2 patient per 100.000 population without striking differences between provinces. Among 39 HMV centers in Poland 12 (31%) answered. They reported 206 patients (24% of all HMV users). Proportion of ventilation mode consisted of 59% (122 pts) treated via a tracheostomy and 41% (84 pts) with non invasive ventilation (NIV). 168 patients (82%) had neuromuscular diseases (ND), majority of them muscular dystrophy - 57 patients ( 34% of ND) and amyotrophic lateral sclerosis - 39 patients (23% of ND). There were only 38 patients (18%) with lung and thoracic cage diseases: 17 with COPD and 10 with kyphoscoliosis. Conclusions: The prevalence of HMV treatment in Poland has developed dramatically in the last decade, but is still very low comparing to other European countries, especially due to very low number of patients with lung and chest wall diseases. The prevalence of invasive mode of ventilation is extremely high. The most important factors which inhibit development of HMV in Poland are: omission of respiratory physicians in the process of qualification, lack of national guidelines, sophisticated demands for HMV providers. The awareness of the need of HMV especially in patients with respiratory failure due to obesity hypoventilation syndrome and restrictive lung diseases should be increased among chest physicians. Pneumonol. Alergol. Pol. 2010; 78, 6: 392-39

TOF-PET detector concept based on organic scintillators

In this contribution we present a new concept of the large acceptance detector systems based on organic scintillators which may allow for simultaneous diagnostic of large fraction of the human body. Novelty of the concept lies in employing large blocks of polymer scintillators instead of crystals as detectors of annihilation quanta, and in using predominantly the timing of signals instead of their amplitudes

Strip- PET : a novel detector concept for the TOF-PET scanner

We briefly present a design of a new PET scanner based on strips of polymer scintillators arranged in a barrel constituting a large acceptance detector. The solution proposed is based on the superior timing properties of the polymer scintillators. The position and time of the reaction of the gamma quanta in the detector material will be determined based on the time of arrival of light signals to the edges of the scintillator strips

Effect of electron beam irradiation on filtering facepiece respirators integrity and filtering efficiency

The outbreak of the COVID-19 pandemic has shown that the demand for medical masks and respirators exceeds the current global stockpile of these items, and there is a dire need to increase the production capacity. Considering that ionizing radiation has been used for sterilization of medical products for many years and electron beam (EB) irradiation enables the treatment of huge quantities of disposable medical products in a short time this method should be tested for the mask’s decontamination. In this work, three different filtering facepiece respirators (FFRs) were irradiated with electron beams of 12 kGy and 25 kGy. The results confirmed that the decrease in filtration efficiency after irradiation of all respirators results from the elimination of the electric charge from the polypropylene (PP) fibers in the irradiation process. Moreover, the applied doses may affect the thermal stability of PP fabrics, while filtering materials structure and integrity have not changed after irradiation

As, Cr, Cd, and Pb in Bee Products from a Polish Industrialized Region

Bee pollen and bee bread from stationary apiaries in the southwest Polish Legnica-Glogow copper district (LGOM) were analyzed for Cr, Pb, Cd and As by ICP-AES. Their concentrations in both products were As > Cr > Pb > Cd. Concentrations in bee pollen were higher than in bee bread. Average Cr, Pb, As and Cd concentrations in bee products were 0.138, 0.093, 0.325, and 0.019 mg kg−1, respectively. Chromium was the most problematic element in bee pollen because its concentration limit was exceeded in more than 50% of the samples. Differences in Cd level between bee pollen and bread were significant (p ≤ 0.05

E-beam irradiation for the control of Phytophthora nicotianae var. nicotianae in stonewool cubes

Effectiveness of electron beam irradiation was evaluated against Phytophthora nicotianae var. nicotianae, the causal agent of stem base and root rot of tomato. In laboratory trials, irradiation of 7-day-old Phytophthora cultures growing on potato-dextrose-agar (PDA) medium with 1 kGy resulted in the disintegration of the pathogen’s hyphae. Increasing the irradiation dose to 3 kGy caused decay of the hyphae. Irradiation of infested stonewool with 5 kGy caused decrease of the pathogen population about 5 times. Application of 20 kGy completely eliminated the pathogen from stonewool. Irradiation of substratum resulted in significant increase of tomato seedlings healthiness, especially when the dose 20 kGy was applied

E-Beam Irradiation and Ozonation as an Alternative to the Sulphuric Method of Wine Preservation

Potassium metabisulphite is usually used for microbial stabilization in the process of vinification and wine preservation, but it is considered to be allergenic. The objective of the present study was to assess the efficiency of ozonation and ionizing radiation as alternatives to wine sulphurization. The efficiency of yeast removal and the retention of the chemical quality of wine were evaluated. Wine was subjected to 60 min of ozonation, and radiation doses were set at 1–10 kGy. Moreover, a combination of ozonation and ionizing radiation treatment was used. The ozonation of wine did not produce the expected results. That is, it did not limit the number of yeast cells. From the sixth minute, a significant deterioration in the taste and the color of the wine was found. Ionizing radiation at a dose of 1 kGy reduced the yeast count by 95.5%, and a reduction of 99.9% was seen after the application of 2.5 kGy. Moreover, these doses did not have a significant effect on the organoleptic properties or the chemical composition of wine. The total amount of polyphenols reduced from the maximum of 1127.15 to 1023.73 mg at the dose of 5 kGy. Radiation is widely used to preserve food products. Its use for finished wine preservation may be an alternative to sulphurization