552 research outputs found

    Arteriovenous fistula of superficial temporal vessels

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    We present a case of patient with a rare vessel pathology — arteriovenous fistula (AVF) of superficial temporal artery and vein. The 56-year-old man was admitted to the Department of Neurology because of a headache in the right temporal region with concomitant buzzing sound in his right ear. The pain was present mainly in the evenings and was stronger when touching the temporal region. He denied having any head injury in the last few years. There were no signs of central nervous system involvement in the neurological examination. Within the right temporal area a subcutaneous mass with redness of the surrounding skin and with palpable and audible pulsatile thrill was observed. In computed tomography (CT) of the head no abnormalities were found. In duplex-Doppler ultrasound examination of carotid arteries the systolic blood velocity in the right external carotid artery was over two times higher than in the left one. Its flow profile was turbulent and low-resistant. In CT angiography (CTA) an AVF between superficial temporal artery and vein was revealed — it was located at the level of the right zygomatic arch. In both CTA and magnetic resonance angiography, no abnormal connections between extra- and intracranial vessels were found. The patient underwent surgery with good result — all the symptoms disappeared. AVFs of vessels of the scalp are rare and their aetiology is mainly traumatic or iatrogenic. By describing this case we wanted to draw attention to less frequent causes of headache

    Program Nauczania W KOMPUTEROWYM ŚWIECIE. Zajęcia komputerowe II etap edukacyjny szkoła podstawowa klasy IV-VI

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    Program nauczania przedmiotu zajęcia komputerowe dla II etapu edukacyjneg

    Comments on the High Pressure Preservation of Human Milk

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    The current state of studies on the high pressure preservation of the human milk is briefly presented. It is indicated that reaching (i) the antimicrobial safety, (ii) antiviral safety, and (iii) high nutritional, metabolic and immunological quality, may be difficult for a “classical” single pressure pulse High Pressure Preservation (HPP) treatment. It is shown that the sudden decompression leads to additional physical processes, which can be important for supporting the HPP technology. Additional advantages were reached due to the two-pulse compression, with subsequent values: P = 200 MPa and 400 MPa. Tests included the microbiological insight for the two-weeks storage. It is also shown that the decay of the number of microorganisms under the high pressure follows the relation n(t) = n0exp(At)exp(Bt2). Finally, issues regarding containers for the high pressure preservation of human milk are discussed

    orchaRd 2.0 : an R package for visualising meta-analyses with orchard plots

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    1. Although meta-analysis has become an essential tool in ecology and evolution, reporting of meta-analytic results can still be much improved. To aid this, we have introduced the orchard plot, which presents not only overall estimates and their confidence intervals, but also shows corresponding heterogeneity (as prediction intervals) and individual effect sizes. 2. Here, we have added significant enhancements by integrating many new functionalities into orchaRd 2.0. This updated version allows the visualisation of heteroscedasticity (different variances across levels of a categorical moderator), marginal estimates (e.g. marginalising out effects other than the one visualised), conditional estimates (i.e. estimates of different groups conditioned upon specific values of a continuous variable) and visualisations of all types of interactions between two categorical/continuous moderators. 3. orchaRd 2.0 has additional functions which calculate key statistics from multilevel meta-analytic models such as I2I^{2} and R2R^{2}. Importantly, orchaRd 2.0 contributes to better reporting by complying with PRISMA-EcoEvo (preferred reporting items for systematic reviews and meta-analyses in ecology and evolution). Taken together, orchaRd 2.0 can improve the presentation of meta-analytic results and facilitate the exploration of previously neglected patterns. 4. In addition, as a part of a literature survey, we found that graphical packages are rarely cited (~3%). We plea that researchers credit developers and maintainers of graphical packages, for example, by citations in a figure legend, acknowledging the use of relevant packages

    Microelectrode-based probing of charge propagation and redox transitions in concentrated polyoxometallate electrolyte of potential utility for redox flow battery

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    Concentrated solutions of Keggin-type silicotungstic acid, as well as the system's single crystals (H4SiW12O40*31H2O) and their colloidal suspensions have been tested using the microelectrode methodology to determine mass-transport, electron self-exchange and apparent (effective) diffusion-type coefficients for charge propagation and homogeneous (electron self-exchange) rates of electron transfers. Silicotungstic acid facilitates proton conductivity, and undergoes fast, reversible, multi-electron transfers leading to the formation of highly conducting, mixed-valence (tungsten(VI,V) heteropoly blue) compounds. To develop useful electroanalytical diagnostic criteria, electroanalytical approaches utilizing microdisk electrodes have been adapted to characterize redox transitions of the system and to determine kinetic parameters. Combination of microelectrode-based experiments performed in two distinct diffusional regimes: radial (long-term experiment; e.g., slow scan rate voltammetry or long-pulse chronoamperometry) and linear (short-term experiment; e.g., fast scan rate voltammetry or short-pulse chronocoulometry) permits absolute determination of such parameters as effective concentration of redox centers (C0) and apparent transport (diffusion) coefficient (Dapp). The knowledge of these parameters, in particular of [Dapp1/2 C0] seems to be of importance to the evaluation of utility of redox electrolytes for charge storage. For the colloidal suspension of silicotungstic acid (H4SiW12O40) crystals in the saturated solution, the following values have been obtained: Dapp = 1.8*10-6 cm2 s−1 and C0 = 1.1 mol dm−3, as well as the [Dapp1/2 C0] diagnostic parameter has reached the value as high as 6*10-3 mol/dm−3 cm s−1/2, provided that four electrons are involved in the H4SiW12O40 redox transitions. In this respect, the fact that crystals (dispersed solids) are characterized by high electron self-exchange rate (kex = 1.1*108 dm3 mol−1 s−1) and low activation energy (EA = 18.7 kJ mol−1) facilitating electron transfers between immobilized WVI and WV redox sites is also advantageous
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