50 research outputs found

    Educational studies of cosmic rays with telescope of Geiger-Muller counters

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    A group of high school students (XII Liceum) in the framework of the Roland Maze Project has built a compact telescope of three Geiger-Muller counters. The connection between the telescope and PC computer was also created and programed by students involved in the Project. This has allowed students to use their equipment to perform serious scientific measurements concerning the single cosmic ray muon flux at ground level and below. These measurements were then analyzed with the programs based on the 'nowadays' knowledge on statistics. An overview of the apparatus, methods and results were presented at several students conferences and recently won the first prize in a national competition of high school students scientific work. The telescope itself, in spite of its 'scientific' purposes, is built in such a way that it is hung on a wall in a school physics lab and counts muons continuously. This can help to raise the interest for studying physics among others. At present a few (3) groups of young participants of the Roland Maze Project have already built their own telescopes for their schools and some others are working on it. This work is a perfect example of what can be done by young people when respective opportunities are created by more experienced researchers and a little help and advice is given.Comment: 5 figures, 10 page

    Prevention of contrast-induced acute kidney injury in patients undergoing cardiovascular procedures : a systematic review and network meta-analysis

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    BACKGROUND: Interventional diagnostic and therapeutic procedures requiring intravascular iodinated contrast steadily increase patient exposure to the risks of contrast-induced acute kidney injury (CIAKI), which is associated with death, nonfatal cardiovascular events, and prolonged hospitalization. The aim of this study was to investigate the efficacy of pharmacological and non-pharmacological treatments for CIAKI prevention in patients undergoing cardiovascular invasive procedures with iodinated contrast.METHODS AND FINDINGS: MEDLINE, Google Scholar, EMBASE and Cochrane databases as well as abstracts and presentations from major cardiovascular and nephrology meetings were searched, up to 22 April 2016. Eligible studies were randomized trials comparing strategies to prevent CIAKI (alone or in combination) when added to saline versus each other, saline, placebo, or no treatment in patients undergoing cardiovascular invasive procedures with administration of iodinated contrast. Two reviewers independently extracted trial-level data including number of patients, duration of follow-up, and outcomes. Eighteen strategies aimed at CIAKI prevention were identified. The primary outcome was the occurrence of CIAKI. Secondary outcomes were mortality, myocardial infarction, dialysis and heart failure. The data were pooled using network meta-analysis. Treatment estimates were calculated as odds ratios (ORs) with 95% credible intervals (CrI). 147 RCTs involving 33,463 patients were eligible. Saline plus N-acetylcysteine (OR 0.72, 95%CrI 0.57-0.88), ascorbic acid (0.59, 0.34-0.95), sodium bicarbonate plus N-acetylcysteine (0.59, 0.36-0.89), probucol (0.42, 0.15-0.91), methylxanthines (0.39, 0.20-0.66), statin (0.36, 0.21-0.59), device-guided matched hydration (0.35, 0.12-0.79), prostaglandins (0.26, 0.08-0.62) and trimetazidine (0.26, 0.09-0.59) were associated with lower odds of CIAKI compared to saline. Methylxanthines (0.12, 0.01-0.94) or left ventricular end-diastolic pressure-guided hydration (0.09, 0.01-0.59) were associated with lower mortality compared to saline.CONCLUSIONS: Currently recommended treatment with saline as the only measure to prevent CIAKI during cardiovascular procedures may not represent the optimal strategy. Vasodilators, when added to saline, may significantly reduce the odds of CIAKI following cardiovascular procedures

    Risks to human and animal health related to the presence of deoxynivalenol and its acetylated and modified forms in food and feed

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    Deoxynivalenol (DON) is a mycotoxin primarily produced by Fusarium fungi, occurring predominantly in cereal grains. Following the request of the European Commission, the CONTAM Panel assessed the risk to animal and human health related to DON, 3-acetyl-DON (3-Ac-DON), 15-acetyl-DON (15-Ac-DON) and DON-3-glucoside in food and feed. A total of 27,537, 13,892, 7,270 and 2,266 analytical data for DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside, respectively, in food, feed and unprocessed grains collected from 2007 to 2014 were used. For human exposure, grains and grain-based products were main sources, whereas in farm and companion animals, cereal grains, cereal by-products and forage maize contributed most. DON is rapidly absorbed, distributed, and excreted. Since 3-Ac-DON and 15-Ac-DON are largely deacetylated and DON-3-glucoside cleaved in the intestines the same toxic effects as DON can be expected. The TDI of 1 μg/kg bw per day, that was established for DON based on reduced body weight gain in mice, was therefore used as a group-TDI for the sum of DON, 3-Ac-DON, 15-Ac-DON and DON-3-glucoside. In order to assess acute human health risk, epidemiological data from mycotoxicoses were assessed and a group-ARfD of 8 μg/kg bw per eating occasion was calculated. Estimates of acute dietary exposures were below this dose and did not raise a health concern in humans. The estimated mean chronic dietary exposure was above the group-TDI in infants, toddlers and other children, and at high exposure also in adolescents and adults, indicating a potential health concern. Based on estimated mean dietary concentrations in ruminants, poultry, rabbits, dogs and cats, most farmed fish species and horses, adverse effects are not expected. At the high dietary concentrations, there is a potential risk for chronic adverse effects in pigs and fish and for acute adverse effects in cats and farmed mink

    Career in vascular surgery – the medical student’s perspective

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    Aim: Under the supervision of the Department of General and Vascular Surgery of Poznan University of Medical Sciences, a questionnaire was distributed online or as a paper version to medical students (MSs) in order to better understand the attitudes towards surgery as a specialty and to determine the reasons why students do and do not choose vascular surgery as their career path. Materials and methods: The questionnaire was distributed online or as a paper version to MSs in the 3rd, 5th, and 6th year of the PUMS 6-year M.D. program. It provided the data on the year of study, grade point average (GPA), sex, age, respondent’s specialty choice, 33 questions with responses on a 1-5 Likert scale (1 was the least important reason and 5 was the most important reason), and 2 questions with socres between 0 and 4. A total of 136 Polish MSs of PUMS completed the survey. Results: For MSs who choose vascular surgery as their career path, “endovascular capabilities of vascular surgery” and “higher income possibilities than a general surgeon” were the most important reasons. The “poor availability of work in other places than the vascular surgery department of your choice, few such clinics in the region” was the most important reason not to choose vascular surgery. A role of gender was also noted - 13% of male MSs classified gender as an “important factor”, in contrast to 60% of female MSs. Conclusions: The findings of this study might help to develop better strategies to attract future trainees to surgical specialties, particularly vascular surgery, and improve work environment

    Prevalence of Chronic Venous Disorders Among Employees Working in Prolonged Sitting and Standing Postures

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    Research was conducted to determine the prevalence and severity of chronic venous disorders (CVD) among people working in prolonged sitting or static standing postures. Clinical examination and duplex Doppler sonography were performed on 126 employees working in a sitting (96 individuals) or a standing posture (30 individuals). Evidence of CVD was found in 59.4% of individuals working in a sitting posture and in 83.4% of those working in a standing posture, and was significantly higher in employees working in a standing posture (p = .015). Incompetent perforating veins and vena saphena magna valves, and bilateral changes were the more frequent signs of CVD. The investigation showed that prolonged standing and sitting at work increases risk of developing CVD. Further, people working in a standing posture are at a significantly greater risk for CVD than those working in a prolonged sitting posture. They should thus be the subject of specific prophylaxis interventions

    Kariera w chirurgii naczyniowej – spojrzenie studenta

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    Cel: Na Oddziale Chirurgii Ogólnej i Naczyń Uniwersytetu Medycznego w Poznaniu wśród studentów rozdystrybuowano medycyny kwestionariusze w wersji papierowej i online. Celem pozyskanych w ten sposób odpowiedzi było lepsze zrozumienie nastawienia studentów do chirurgii jako specjalizacji oraz określenie przyczyn, dla których chcą, lub nie chcą, dokonywać wyboru chirurgii naczyniowej jako ścieżki dalszej kariery. Materiały i metody: Kwestionariusz rozdystrybuowano w wersji papierowej i online studentom III, V i VI roku 6-letnich studiów medycznych na UMP. Zebrano dane dotyczące: roku studiów, średniej ocen, płci, wieku, wyboru specjalizacji, odpowiedzi na 33 pytania oceniane w skali Likerta 1–5 (1 –najmniej istotna przyczyna, 5 – najbardziej istotna), a także dwa pytania oceniane w skali 0–4. Ankietę wypełniło łącznie 136 polskich studentów medycyny na UMP. Wyniki: Wśród studentów, którzy zadeklarowaliwybór chirurgii naczyniowej, najistotniejszymi powodami decyzji były „endowaskularne możliwości leczenia w chirurgii naczyniowej” oraz „dochód wyższy niż chirurga ogólnego”. Najważniejszy powód niewybierania tej specjalizacji stanowił „brak możliwości zatrudnienia w innych placówkach niż oddziały chirurgii naczyniowej, niewielka ilość tego typu oddziałów w regionie”. Odnotowano również wpływ płci – aż 60% kobiet i tylko 13% mężczyzn uznało w ankiecie płeć za „istotny czynnik wyboru specjalizacji z zakresu chirurgii naczyniowej” Wnioski: Wyniki naszego badania mogą pomóc w opracowaniu lepszych strategii zachęcania przyszłych lekarzy do wyboru specjalizacji zabiegowych, szczególnie chirurgii naczyniowej oraz w poprawie warunków prac

    Synthesis and characterization of hydroxyapatite/chitosan composites

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    Hydroxyapatite (HAp)/chitosan (CS) composites were synthesized via a one-step co-precipitation method from aqueous solution, with the use of calcium chloride (CaCl2) and disodium hydrogen phosphate (Na2HPO4). CS was obtained via partial deacetylation of chitin with the use of strong sodium hydroxide solution. Composites were prepared with various HAp/CS ratios (30/70, 50/50, 70/30, 85/15) for comprehensive comparison of their properties. Fourier Transform Infrared Spectroscopy (FT-IR) analysis showed that hydrogen bonds were formed between the organic matrix and the mineral compound, confirming a successful phase interconnection. X-ray diffraction patterns were obtained, enabling examination of the crystalline properties of the composites, including HAp identification. The porous structure parameters of the composites were investigated, and morphological analysis (SEM) was performed. Differential Thermal Gravimetry (DTG) analysis of the composites indicated that the material is thermally stable up to 200 oC. Additionally, Energy Dispersive Spectroscopy (EDS) analysis of the mineral was carried out to check the Ca/P ratio, and confirmed its similarity to pure HAp
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