Verification of doses in electron beam radiotherapy

Entrance doses measured in 50 patients treated by electron beams were compared with planned values as the percentage difference between the given dose and its planned value. Electron beams of energy 6, 9, 12, 15, 18 and 22 MeV were generated by the Clinac 2300 C/D linear accelerator (Varian). Semiconductor EDE-5 diodes connected to a DPD-510 (Scanditronix) electrometer were applied for entrance dose measurements. In our investigations, the mean values of doses administered agreed well with the values of planned doses. The observed relatively large discrepancies in a few patients (up to 12%) should be carefully investigated

Analysis of risk factors for nosocomial infections in the Neonatal Intensive Care Unit of the Pomeranian Medical University in Szczecin in the years 2005-2008

Summary The aim of the study was to assess the significance of some perinatal risk factors and neonatal complications in occurrence of nosocomial infections in the population of NICU patients. Material and methods: Analysis of risk factors was performed in all patients treated in the years 2005-2008 in NICU Department of the Pomeranian Medical University in Szczecin, Poland. Five hundred and seventeen neonates divided into groups with and without occurrence of nosocomial infection were included into the study. Results: Seventy nine (15.28%) neonates developed nosocomial infection. Among them pneumonia (56.96%) and sepsis (21.5%) were the most common. The proportion of Gram-positive and Gram negative organisms were 44.3% and 50.6% respectively. The main risk factor for nosocomial infection was colonization (sensitivity - 100% and specificity – 94.75%). Univariate analysis showed that premature rupture of fetal membrane, GA< 32 hbd, birthweigh

The absorption spectrum of 13 CH 4 at 80 K and 296 K near 1.73 µm

International audienc

Analytical-function correction to the Hartmann–Tran profile for more reliable representation of the Dicke-narrowed molecular spectra

International audienc

Thermal and epithermal neutrons in the vicinity of the Primus Siemens biomedical accelerator

In this paper, the thermal and epithermal neutron fluence distributions in the vicinity of the Primus Siemens accelerator are presented. The measurements were carried out by the use of the neutron activation method for 15 MV X-rays and electron beams of 18 MeV and 21 MeV. From the radiation safety point of view for the hospital personnel, it is important to know the thermal and epithermal neutron fluence distribution in the vicinity of the accelerator because the neutrons interacting with atoms of a medium by various processes induce the activity of objects (accelerator, other apparatus etc.) and walls in the treatment room. The thermal and epithermal neutron capture, particularly, in high atomic number materials of the accelerator head can be a significant source of gamma radiation and it has to be taken into account for estimation of the work safety of the personnel. Values of the neutron fluence were normalized to the maximum photon (or electron) dose Dmax,gamma (e) measured at the central axis of therapeutic X-ray (or electron) beam in a water phantom. The thermal neutron fluences measured during the 15 MV X-ray emission varied between 1.1 × 10 5 n ź cm 2ź Gy -1 and 4.4 × 10 5 n ź cm -2ź Gy 1 whereas the epithermal neutron fluences ranged from 0.2 × 10 5 n ź cm 2ź Gy- 1 to 1.8 × 105 n ź cm -2ź Gy -1. In the case of electron beams, the neutron fluence measurements were performed only at the isocentre. The obtained thermal and epithermal neutron fluences were 1.2 × 10 4 n ź cm -2ź Gy -1 and 0.6 × 10 4 n ź cm -2ź Gy -1, respectively, for the 18 MeV electrons. In the the case of the 21 MeV electron beams the thermal neutron fluence was -2.0 × 10 4 n ź cm -2ź Gy -1 whereas the epithermal neutron fluence was 0.8 × 10 4 n ź cm -2ź Gy-1

Surface modification of titanium with plasmochemical methods

W pracy przedstawiono wyniki badań nad modyfikacją powierzchni tytanu Ti Grade 2 warstwami a-C: H i a-C:N:H oraz warstwami węgloazotku krzemu SiCxNy(H) przy zastosowaniu metody chemicznego osadzania z fazy gazowej ze wspomaganiem plazmowym MWCVD (2kW, 2.45GHz) oraz RFCVD (400W, 13.45MHz). W roli prekursorów gazowych zastosowano NH3, N2, CH4, H2, SiH4 oraz Ar. Określono zachowanie korozyjne w roztworze sztucznej śliny otrzymanych układów warstwa-podłoże metaliczne w porównaniu z niemodyfikowanymi metalami.The paper presents results of research on titanium Ti Grade 2 surface modification with a-C:H, a-C:N:H and silicon carbonitride SiCxNy(H) layers synthesis by plasma assisted chemical vapour deposition method MWCVD (2kW, 2.45GHz) and RFCVD (400 W, 13.45MHz). As a gas precursors NH3, N2, CH4, H2, SiH4 and Ar were used. Corrosion behaviour of obtained systems in the solution of artificial saliva determined in comparison with the unmodified metal

Chemiczne osadzanie z fazy gazowej wspomagane plazmowo – projektowanie technologii funkcjonalnych powłok

Plasma Assisted Chemical Vapour Deposition (PA CVD) method allows to deposit of homogeneous, well-adhesive coatings at lower temperature on different substrates. Plasmochemical treatment significantly impacts on physicochemical parameters of modified surfaces. In this study we present the overview of the possibilities of plasma processes for the deposition of diamond-like carbon coatings doped Si and/or N atoms on the Ti Grade2, aluminum-zinc alloy and polyetherketone substrate. Depending on the type of modified substrate had improved the corrosion properties including biocompatibility of titanium surface, increase of surface hardness with deposition of good adhesion and fine-grained coatings (in the case of Al-Zn alloy) and improving of the wear resistance (in the case of PEEK substrate).Metoda chemicznego otrzymywania warstw z fazy gazowej w warunkach plazmy (PA CVD – Plasma Assisted Chemical Vapour Deposition) umożliwia otrzymywanie homogenicznych struktur warstwowych w niskich temperaturach, o dobrej adhezji do podłoży. Warunki w jakich prowadzone są procesy plazmochemiczne w znacznym stopniu decydują o właściwościach fizykochemicznych modyfikowanych powierzchni. W pracy przedstawiono możliwości w zakresie projektowania procesów plazmochemicznych z otrzymaniem warstw DLC (Diamond-like Carbon) dotowanych atomami Si i/lub N. W zależności od rodzaju modyfikowanego podłoża uzyskano poprawę właściwości korozyjnych przy zachowaniu biokompatybilności powierzchni (w przypadku Ti Grade2), poprawę twardości powierzchni na drodze otrzymania drobnoziarnistej powłoki o dobrej adhezji do podłoża (w przypadku Al-Zn) i poprawę odporności na zużycie (w przypadku PEEK)

Characteristics of external loads of Hockey5s associated with the new version of U16 youth field hockey competition

Abstract External workloads associated Hockey 5 s, the new version of youth field hockey, were evaluated in 31 elite U16 male field players (15.4 ± 0.7 years) from three national teams. Mixed-longitudinal observations for the 31 players provided complete data for 33 forwards and 43 defenders. Activities of the players during games were monitored with the GPSports SPI Elite System with a sampling frequency of 10 Hz and were analysed with GPSports Team AMS (version R1 2015.14, Australia). Observed variables did not differ between forwards and defenders, and the three periods of play were differentiated only by maximal speed in the second and third periods. The greatest distances covered were in speed zone 3 (10.0–15.9 km h−1; 35.5–38.2%) and the smallest in speed zones 4 (16.0–22.9 km h−1; 14.8–15.6%) and 5 (> 23 km h−1; 0.4–1.4%). The trends indicated high intensity levels for the entire match and by position and periods. Active time of forwards and defenders accounted for about one-half of a game’s duration (~ 15.7 of 30 min). Overall, the Hockey 5s format was highly demanding of players and included relatively short intervals for recovery. The results emphasize the need for preparation that includes specific mixed anaerobic and aerobic training and also the importance of recovery during breaks

Scavenging of reactive oxygen species by phenolic compound-modified maghemite nanoparticles

Maghemite (γ-Fe2O3) nanoparticles obtained through co-precipitation and oxidation were coated with heparin (Hep) to yield γ-Fe2O3@Hep, and subsequently with chitosan that was modified with different phenolic compounds, including gallic acid (CS-G), hydroquinone (CS-H), and phloroglucinol (CS-P), to yield γ-Fe2O3@Hep-CS-G, γ-Fe2O3@Hep-CS-H, and γ-Fe2O3@Hep-CS-P particles, respectively. Surface modification of the particles was analyzed by transmission electron microscopy, dynamic light scattering, attenuated total reflection Fourier transform infrared spectroscopy, and thermogravimetric analysis. Magnetic measurements indicated that the polymer coating does not affect the superparamagnetic character of the iron oxide core. However, magnetic saturation decreased with increasing thickness of the polymer coating. The antioxidant properties of the nanoparticles were analyzed using a 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. Cellular uptake and intracellular antioxidant activity of the particles were evaluated by an iron assay and flow cytometry, respectively, using L-929 and LN-229 cells. Compared to the control, the phenolic modification significantly reduced intracellular reactive oxygen species (ROS) levels to 35–56%, which was associated with a 6–8-times higher cellular uptake in L-929 cells and a 21–31-times higher cellular uptake in LN-229 cells. In contrast, γ-Fe2O3@Hep particles induced a 3.8-times and 14.9-times higher cellular uptake without inducing antioxidant activity. In conclusion, the high cellular uptake and the antioxidant properties associated with the phenolic moieties in the modified particles allow for a potential application in biomedical areas