469 research outputs found
Prevalence of congenital coronary artery anomalies and variants in 726 consecutive patients based on 64-slice coronary computed tomography angiography
Background: Coronary computed tomography angiography (CCTA) is helpful in making a precise noninvasive evaluation of coronary anatomy, allowing concomitant evaluation of other cardiac structures. The aim of this study was to determine the prevalence of coronary artery variations detected by 64-slice mutidetector CT.
Materials and methods: The results of ECG-gated CCTA in 726 consecutive patients (mean age 58 years) were analysed retrospectively. The main indicationsfor CCTA were a typical chest pain, angina pectoris, screening for coronary artery disease and determination of the patency of bypass grafts or stents. Acquisitionwas performed with a 64-detector CT scanner with retrospective ECG gating. Imaging results were assessed by experienced cardiovascular radiologist.
Results: The overall incidence of coronary artery anomalies was 1.1% (8 out of 726 participants). The most common anomaly was an anomalous origin of the circumflex artery from the right coronary sinus with a retroaortic course (4 patients,0.6%), followed by origin of right coronary artery from the left coronary sinus (2 patients, 0.3%). One patient with abnormal origin of the left main artery from the right coronary sinus (0.1%) and 1 patient with a circumflex artery origin from the proximal segment of the right coronary artery (0.1%) were observed, both with retroartic course.
Conclusions: CCTA is a noninvasive imaging technique useful for the precise evaluation of variations of the coronary arteries. This study shows similar results to other reports on this subject.
Persistent left superior vena cava with an absent right superior vena cava in a 72-year-old male with multivessel coronary artery disease
Congenital anomalies of systemic veins are usually asymptomatic and foundincidentally during ultrasonography, computed tomography (CT) or magneticresonance examinations performed for other clinical indications. Persistent leftsuperior vena cava (PLSVC) with absent right superior vena cava (RSVC) is thecongenital aberration in the thoracic venous system which occurs in only 0.09%to 0.13% of patients who have congenital heart defects. In this paper, we presentthe extremely rare case of a 72-year-old male with PLSVC associated withan absence of RSVC, referred for coronary CT angiography. Multidetector CTangiography is a powerful tool for the detection of venous anomalies, which isessential before invasive procedures such as the implantation of pacemakers
Broadband dielectric spectroscopy of nanocomposites based on PVDF and expanded graphite
International audienceNanocomposites based on poly (vinylidene fluoride) (PVDF) and expanded graphite (EG) were prepared by non-solvent precipitation from solution with different EG concentrations. Films were obtained by compression molding and their structural and dielectric properties studied. From Wide Angle X-ray Scattering (WAXS) experiments, it can be assessed that for all EG concentrations the -crystalline phase of PVDF is the predominant crystalline form. However, for composites with high nanoadditive content, higher than 3 wt.%, the -crystalline phase is also detected. Dielectric spectroscopy results showed that the nanocomposites present both high dielectric constant and electrical conductivity at low percolation threshold
Electrically conductive PTT-block-PTMO/SWCNTs+Graphene Nanoplatelets hybrid nanocomposites prepared by in situ polymerization
Hybrid Materials 2015; Sitges, Barcelona, Spain, 9 - 13 March 2015The studies were financed by the National Science Centre within project PRELUDE no
2013/11/N/ST8/00404.Peer Reviewe
The conception of management of post-industrial landscapes in the light of sustainable development
В сборнике материалов конференции отражены научно-методические и прикладные результаты научных исследований, анализа, оценки, регулирования, картографического и ГИС-обеспечения современных структурных и региональных сдвигов в мировом хозяйстве, социально-экономической модернизации стран и регионов СНГ в условиях глобализации, инновационных факторов социально-экономического развития регионов Беларуси, демографического развития и социально-демографических рисков стран, современных региональных проблем развития туризма, природно-ресурсного потенциала стран и регионов, геоэкологических аспектов стратегии устойчивого развития. Адресуется преподавателям, научным работникам, студентам и аспирантам вузов, сотрудникам органов управления
The late Vistulian and Holocene evolution of Jezioro Lake : a record of environmental change in southern Poland found in deposits and landforms
Jezioro Lake is the only natural lake in
southern Poland outside mountainous areas to have
existed continuously since the Pleistocene. The record
of environmental change in the Late Vistulian
(Weichselian) and Holocene is preserved in the
deposits and landforms around the lake. This paper
presents the results of paleogeographical and paleoecological
research that emabled us to reconstruct the
history of the Jezioro Lake. At the end of the Vistulian
period, the outlet of the lake was blocked by a
parabolic dune moving in from the west. Limnic
sedimentation was evident in the sediment core at all
levels from the Holocene, with remains of Cladocera,
Chironomidae larvae, and aquatic plants. The lake did
not disappear at that time, although its area decreased
by a factor of 12 by the end of the period. Paleobotanical
research permitted the reconstruction of
sequences of plant communities and changes in
nutrient status and water level. An initial oligotrophic
lake, as indicated by the presence of Isoe¨tes lacustris
L., changed to a eutrophic lake, as indicated by the
presence of Potamogeton natans L. and Nuphar sp.,
then the lake progressed to the present-day dystrophic
lake that is surrounded by a swamp. The profile of organic deposits contains a record of environmental
change at least since the Younger Dryas in southern
Poland
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