Stability of technetium in the moderate oxidation states in acidic media

Technetium is one of the most important radionuclides in the spent nuclear fuel in context of reprocessing, storage and long term disposal. Spectroelectrochemical studies on the redox behavior of this element are presented and possible pathways of pertechnetate ions reduction are discussed. The stability of technetium (III/IV) species are discussed

Noise analysis of the longitudinal paper cutting machine in the context of declaration of compliance of the machinery

Noise analysis of the longitudinal paper cutting machine in the context of declaration of compliance of the machiner

Effect of the alloying metal on the corrosion resistance of Pd-rich binary alloys with Pt, Rh, and Ru in sulfuric acid

The paper presents the study of the corrosion resistance of electrodeposited Pd and its binary alloys with Pt, Rh, and Ru on a polycrystalline Au substrate. The corrosion resistance was tested in 0.5 M sulfuric acid at room temperature using potentiodynamic polarization and electrochemical impedance spectroscopy techniques. The morphology/composition and work function values were determined by scanning electron microscopy/energy–dispersive X–ray spectroscopy and scanning Kelvin probe, respectively. The obtained results revealed that the Pd electrode is the most resistant to corrosion, whereas the Pd-Ru electrode is the most susceptible to dissolution. It was found that the corrosion resistance of Pd-binary alloys decrease in the following order: Pd > Pd-Pt > Pd-Rh > Pd-Ru. This effect was assigned mainly to the difference in surface roughness factor of tested electrodes

The influence of physiotherapy on the concentration of interleukin-8 in patients suffering from chronic obstructive pulmonary disease

Wstęp: Interleukina-8, chemokina produkowana przez makrofagi i komórki nabłonka, silny chemoatraktant dla neutrofili, odgrywa zasadniczą rolę w aktywacji neutrofilów i eozynofilów w drogach oddechowych u chorych na POChP i może służyć jako marker nasilenia reakcji zapalnej. Zapalenie to w przypadku pacjentów z POChP może charakteryzować się zwiększoną liczbą neutrofilów w plwocinie, a także podwyższonym stężeniem interleukiny-8. Celem niniejszej pracy było określenie wpływu fizjoterapii na stężenie interleukiny-8 w indukowanej plwocinie u chorych na POChP. Materiał i metody: Badaniami objęto 44 chorych (21 mężczyzn, 23 kobiety, średnia wieku 56,47 &#177; 9,52) leczonych w SP ZOZ Szpitalu Specjalistycznym MSWiA w Głuchołazach, usprawnianych w Dziale Usprawniania Leczniczego, z rozpoznaną POChP (wskaźnik FEV1%VC < 65%), z niezmieniającym się leczeniem farmakologicznym w trakcie fizjoterapii. U wszystkich chorych przed fizjoterapią przeprowadzono test wydolnościowy na bieżni ruchomej według zmodyfikowanego protokołu Bruce&#8217;a oraz dokonano oceny duszności na podstawie 20-punktowej skali Borga w celu kwalifikacji do fizjoterapii. U wszystkich chorych zastosowano kompleksową 3-tygodniową fizjoterapię pulmonologiczną, której podstawą był trening wydolnościowy na ergometrze rowerowym. Wielkość obciążeń treningowych dobierano indywidualnie dla każdego chorego na podstawie oceny tolerancji wysiłku. Standardowy program fizjoterapii obejmował również ćwiczenia mięśni oddechowych, ze szczególnym uwzględnieniem mięśni brzucha i przepony, inhalacje z roztworu izotonicznego NaCl, drenaż ułożeniowy z oklepywaniem klatki piersiowej, relaksację oraz spacery. U wszystkich chorych oznaczono stężenie IL-8 w indukowanej plwocinie przed rozpoczęciem kompleksowej fizjoterapii i po jej zakończeniu. Stężenie IL-8 określono za pomocą testu ELISA. Wyniki: Wykazano, że stężenie interleukiny-8 było istotnie niższe po 3-tygodniowej fizjoterapii. Interleukina-8 w plwocinie spadła od 18,91 &#177; 25,2 do 9,69 &#177; 14,06 ng/ml (p = 0,0215). Największy spadek stężenia IL-8 dotyczył chorych z jej najwyższym wyjściowym stężeniem. Wnioski: Obniżenie stężenia IL-8 w indukowanej plwocinie po kompleksowej fizjoterapii chorych na POChP wskazuje na obniżenie aktywności neutrofilów, co może być jedną z przyczyn poprawy stanu klinicznego pacjentów. Pneumonol. Alergol. Pol. 2011; 79, 3: 184&#8211;188Background: Interleukin-8 (IL-8, CXCL8), chemokine produced by macrophages and epithelium cells, plays a major role in activating neutrophils and eosinophils in the airways of patients with COPD and might act as a stimulator of inflammatory process. The aim of the research was to assess whether pulmonary physiotherapy influences the concentration of IL-8 in the induced sputum of patients with COPD. Material and methods: The study included 44 patients (21 males, 23 females, average age 56.47 &#177; 9.52) with COPD treated in Physiotherapy Department of MSWiA Hospital in Glucholazy, with unchanged pharmacological treatment for the duration of the therapy. Before treatment, efficiency treadmill test by Bruce modified protocol and dyspnea assessment with the modified 20-point Borg scale was given to qualify each patient for physiotherapy. All patients participated in a 3-week multi-treatment pulmonary physiotherapy programme based on efficiency training on a cycloergometer. The physical workload was determined individually for each patient based on the assessment of individual exercise tolerance. Standard physiotherapy programme also included respiratory muscles&#8217; training with particular emphasis on training of abdominal muscles and diaphragm, inhalations with isotonic saline, drainage, chest clapping, relaxations and walking. IL-8 concentration in each patient&#8217;s induced sputum was collected prior to complex physiotherapy, and after it has been completed. IL-8 concentration was determined with the use of the ELISA test. Results: It was found that the concentration of IL-8 was significantly lower in patients with COPD after a 3-week physiotherapy programme. It fell from 18.91 &#177; 25.2 to 9.69 &#177; 14.06 ng/ml (p = 0.0215). The most significant IL-8 concentration decrease was observed in patients with the highest initial level of IL-8. Conclusions: The study shows that multi-treatment pulmonary physiotherapy causes decrease of IL-8 level in the induced sputum in patients with COPD, what can suggest decrease activity of neutrophils, which may be one of the factors leading to the improvement in patients&#8217; clinical condition. Pneumonol. Alergol. Pol. 2011; 79, 3: 184-18

3D PET image reconstruction based on Maximum Likelihood Estimation Method (MLEM) algorithm

Positron emission tomographs (PET) do not measure an image directly. Instead, they measure at the boundary of the field-of-view (FOV) of PET tomograph a sinogram that consists of measurements of the sums of all the counts along the lines connecting two detectors. As there is a multitude of detectors build-in typical PET tomograph structure, there are many possible detector pairs that pertain to the measurement. The problem is how to turn this measurement into an image (this is called imaging). Decisive improvement in PET image quality was reached with the introduction of iterative reconstruction techniques. This stage was reached already twenty years ago (with the advent of new powerful computing processors). However, three dimensional (3D) imaging remains still a challenge. The purpose of the image reconstruction algorithm is to process this imperfect count data for a large number (many millions) of lines-of-responce (LOR) and millions of detected photons to produce an image showing the distribution of the labeled molecules in space.Comment: 10 pages, 7 figure

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

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

Multiple scattering and accidental coincidences in the J-PET detector simulated using GATE package

Novel Positron Emission Tomography system, based on plastic scintillators, is developed by the J-PET collaboration. In order to optimize geometrical configuration of built device, advanced computer simulations are performed. Detailed study is presented of background given by accidental coincidences and multiple scattering of gamma quanta

Plastic scintillators for positron emission tomography obtained by the bulk polymerization method

This paper describes three methods regarding the production of plastic scintillators. One method appears to be suitable for the manufacturing of plastic scintillator, revealing properties which fulfill the requirements of novel positron emission tomography scanners based on plastic scintillators. The key parameters of the manufacturing process are determined and discussed.Comment: 7 pages, 4 figure

Application of the compress sensing theory for improvement of the TOF resolution in a novel J-PET instrument

Nowadays, in positron emission tomography (PET) systems, a time of fl ight (TOF) information is used to improve the image reconstruction process. In TOF-PET, fast detectors are able to measure the difference in the arrival time of the two gamma rays, with the precision enabling to shorten signifi cantly a range along the line-of-response (LOR) where the annihilation occurred. In the new concept, called J-PET scanner, gamma rays are detected in plastic scintillators. In a single strip of J-PET system, time values are obtained by probing signals in the amplitude domain. Owing to compressive sensing (CS) theory, information about the shape and amplitude of the signals is recovered. In this paper, we demonstrate that based on the acquired signals parameters, a better signal normalization may be provided in order to improve the TOF resolution. The procedure was tested using large sample of data registered by a dedicated detection setup enabling sampling of signals with 50-ps intervals. Experimental setup provided irradiation of a chosen position in the plastic scintillator strip with annihilation gamma quanta