149 research outputs found

    Interpreting myocardial perfusion scintigraphy using single-photon emission computed tomography. Part 1

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    This article discusses the protocol for myocardial perfusion scintigraphy performed with single-photon emission computed tomography (SPECT). Indications for SPECT are listed with consideration given to the results of the increasingly more common angio-CT examinations of the coronary arteries (multislice computed tomography). The paper also presents basic information about interpreting the results, including the scores of left ventricle myocardial perfusion using the 17-segment polar map, and explains the concept of total perfusion deficit

    Predominant location of coronary artery atherosclerosis in the left anterior descending artery. The impact of septal perforators and the myocardial bridging effect

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    INTRODUCTION: Coronary artery atherosclerosis presents characteristic patterns of plaque distribution despite systemic exposure to risk factors. We hypothesized that local hemodynamic forces induced by the systolic compression of intramuscular septal perforators could be involved in atherosclerotic processes in the left anterior descending artery (LAD) adjacent to the septal perforators' origin. Therefore we studied the spatial distribution of atherosclerosis in coronary arteries, especially in relation to the septal perforators' origin. MATERIAL AND METHODS: 64-slice computed tomography angiography was performed in 309 consecutive patients (92 male and 217 female) with a mean age of 59.9 years. Spatial plaque distribution in the LAD was analyzed in relation to the septal perforators' origin. Additionally, plaque distribution throughout the coronary artery tree is discussed. RESULTS: The coronary calcium score (CCS) was positive in 164 patients (53.1%). In subjects with a CCS > 0, calcifications were more frequent in the LAD (n = 150, 91.5%) compared with the right coronary artery (RCA) (n = 94, 57.3%), circumflex branch (CX) (n = 76, 46.3%) or the left main stem (n = 42, 25.6%) (p < 0.001). Total CCS was higher in the LAD at 46.1 (IQR: 104.2) and RCA at 34.1 (IQR: 90.7) than in the CX at 16.8 (IQR: 61.3) (p = 0.007). In patients with calcifications restricted to a single vessel (n = 54), the most frequently affected artery was the LAD (n = 42, 77.8%). In patients with lesions limited to the LAD, the plaque was located mostly (n = 37, 88.1%) adjacent to the septal perforators' origin. CONCLUSIONS: We demonstrated that coronary calcifications are most frequently located in the LAD in proximity to the septal branch origin. A possible explanation for this phenomenon could be the dynamic compression of the tunneled septal branches, which may result in disturbed blood flow in the adjacent LAD segment (milking effect)

    Polymorphism of the flap endonuclease 1 gene in keratoconus and Fuchs endothelial corneal dystrophy

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    Oxidative stress is implicated in the pathogenesis of many diseases, including serious ocular diseases, keratoconus (KC) and Fuchs endothelial corneal dystrophy (FECD). Flap endonuclease 1 (FEN1) plays an important role in the repair of oxidative DNA damage in the base excision repair pathway. We determined the association between two single nucleotide polymorphisms (SNPs), c.-441G>A (rs174538) and g.61564299G>T (rs4246215), in the FEN1 gene and the occurrence of KC and FECD. This study involved 279 patients with KC, 225 patients with FECD and 322 control individuals. Polymerase chain reaction (PCR) and length polymorphism restriction fragment analysis (RFLP) were applied. The T/T genotype of the g.61564299G>T polymorphism was associated with an increased occurrence of KC and FECD. There was no association between the c.-441G>A polymorphism and either disease. However, the GG haplotype of both polymorphisms was observed more frequently and the GT haplotype less frequently in the KC group than the control. The AG haplotype was associated with increased FECD occurrence. Our findings suggest that the g.61564299G>T and c.-441G>A polymorphisms in the FEN1 gene may modulate the risk of keratoconus and Fuchs endothelial corneal dystrophy.peer-reviewe

    Educating diabetics

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    Cukrzyca podobnie jak wiele innych chorób jest nieuleczalna. Diabetycy, aby mogli skutecznie kontrolować i panować nad chorobą muszą znać jej tajniki. Dogłębne poznanie choroby pozwoli na przewidywanie reakcji, z jakimi można się spotkać. Nieodzownym elementem w leczeniu cukrzycy typu 1 oprócz insulinoterapii jest sposób żywienia. I właśnie zasadom żywienia w cukrzycy poświęcony jest niniejszy artykuł.Like many other illnesses, diabetes is incurable. In order to have the illness under control in a proper manner, diabetics must know all the details related to it. An in-depth knowledge on the disease allows them to anticipate possible reactions. Apart from insulin therapy, an essential element of the treatment of type 1diabetes is a proper diet. This article is devoted precisely to the way diabetics should select their food

    Integration of fluorescent, NV-rich nanodiamond particles with AFM cantilevers by focused ion beam for hybrid optical and micromechanical devices

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    In this paper, a novel fabrication technology of atomic force microscopy (AFM) probes integrating cantilever tips with an NV-rich diamond particle is presented. Nanomanipulation techniques combined with the focused electron beam-induced deposition (FEBID) procedure were applied to position the NV-rich diamond particle on an AFM cantilever tip. Ultrasonic treatment of nanodiamond suspension was applied to reduce the size of diamond particles for proper geometry and symmetry. The fabricated AFM probes were tested utilizing measurements of the electrical resistance at highly oriented pyrolytic graphite (HOPG) and compared with a standard AFM cantilever performance. The results showed novel perspectives arising from combining the functionalities of a scanning AFM with optically detected magnetic resonance (ODMR). In particular, it offers enhanced magnetometric sensitivity and the nanometric resolution

    The monitoring of glycaemia concentration

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    Jedną z najważniejszych rzeczy jakiej muszą nauczyć się diabetycy to kontrola glikemii. Autorzy w artykule omawiają zasady funkcjonowania i posługiwania się glukometrem. Szczegółowiej charakteryzują także urządzenia do pobierania krwi kapilarnej, oraz urządzenia alternatywne służące temu procederowi. Podkreślają także znaczenie oznaczeń stężenie hemoglobiny glikowanej u diabetyków.One of the most crucial things diabetics have to learn is controlling the glycaemia concentration. In this paper, the description of functions and operation of a glucometer is offered. Devices used to draw capillary blood and their substitutes are characterised in greater detail. Moreover, the significance of glycated haemoglobin measures for diabetics

    The self-care of diabetics : the role of a nurse

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    Chorzy na cukrzycę powinni stać się samowystarczalni w zakresie kontroli stężenia glukozy we krwi oraz wstrzyknięć insuliny do tkanki podskórnej. Posiadanie tych umiejętności nie uzależnia ich od innych osób. Stawiają się w komfortowej sytuacji, jaką jest zdolność do samoopieki. Wychodząc naprzeciw tej tezie autorzy omawiają korzystanie ze strzykawki do wstrzyknięć insuliny, charakteryzują obsługę automatycznych wstrzykiwaczy ( PEN-ów). Przedstawiają także nowoczesne rozwiązania techniczne stosowane w leczeniu chorych na cukrzycę insulinozależną.Diabetics should become self-sufficient as far as controlling their glucose level and injecting insulin to the subcutaneous tissue are concerned. Having these skill makes them independent from the help of others. It puts them in a convenient position of being capable of self-care. With the intention of exploring this matter, the authors discuss using the syringe to inject insulin and characterize the use of automatic injectors (pens). They also present modern technological solutions used for treating the insulin-dependent diabetics

    Radiological features of sacrococcygeal teratomas in fetal magnetic resonance imaging and computed tomography : a case report

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    Purpose: Sacrococcygeal teratomas (SCT) can be detected in ultrasonography as early as in the first trimester. Currently, prenatal ultrasonography enables a thorough examination of tumors, but it is not always sufficient. The purpose of this study was to determine the most important features of SCTs in fetal magnetic resonance imaging and to confront them with postnatal computed tomography (CT). Case report: Between 2009 and 2013, 5 cases of sacrococcygeal teratomas were diagnosed in our hospital using fetal magnetic resonance imaging (3 female and 2 male infants). Three of the affected newborns underwent postnatal CT before surgery. In each case, tumor size, its content, mass effect, and classification according to the Altman’s criteria were determined and compared with other features. Fetal magnetic resonance imaging (MRI) and postnatal CT were in excellent agreement with respect to tumor classification using the aformentioned criteria. MRI better characterizes tumor content and its extent compared to ultrasound, and enables a precise structural assessment of the central nervous system. Postnatal CT is complementary to fetal MRI and optional. Conclusions: Fetal MRI may help in the prenatal diagnosis of SCTs as it overcomes the limitations of obstetric ultrasound. Postnatal computed tomography is useful in determining tumor vascularity or calcifications, and it can depict the surrounding bone structures

    Enhanced near-infrared response of nano- and microstructured silicon/organic hybrid photodetectors

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    Heterojunctions between an organic semiconductor and silicon are an attractive route to extending the response of silicon photodiodes into the near infrared (NIR) range, up to 2000 nm. Silicon-based alternatives are of interest to replace expensive low band-gap materials, like InGaAs, in telecommunications and imaging applications. Herein, we report on the significant enhancement in NIR photodetector performance afforded by nano- and microstructuring of p-doped silicon (p-Si) prior to deposition of a layer of the organic semiconductor Tyrian Purple (TyP). We show how different silicon structuring techniques, namely, electrochemically grown porous Si, metal-assisted chemical etching, and finally micropyramids produced by anisotropic chemical etching (Si μP), are effective in increasing the NIR responsivity of p-Si/TyP heterojunction diodes. In all cases, the structured interfaces were found to give photodiodes with superior characteristics as compared with planar interface devices, providing up to 100-fold improvement in short-circuit photocurrent, corresponding with responsivity values of 1–5  mA/W in the range of 1.3–1.6 μm. Our measurements show this increased performance is neither correlated to optical effects, i.e., light trapping, nor simply to geometric surface area increase by micro- and nanostructuring. We conclude that the performance enhancement afforded by the structured p-Si/organic diodes is caused by a yet unresolved mechanism, possibly related to electric field enhancement near the sharp tips of the structured substrate. The observed responsivity of these devices places them closer to parity with other, well-established, Si-based NIR detection technologies
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