106 research outputs found
A fast algorithm for vision-based hand gesture recognition for robot control
We propose a fast algorithm for automatically recognizing a limited set of gestures from hand images for a robot control application. Hand gesture recognition is a challenging problem in its general form. We consider a fixed set of manual commands and a reasonably structured environment, and develop a simple, yet effective, procedure for gesture recognition. Our approach contains steps for segmenting the hand region, locating the fingers, and finally classifying the gesture. The algorithm is invariant to translation, rotation, and scale of the hand. We demonstrate the effectiveness of the technique on real imagery
The role of dislocation-induced scattering in electronic transport in GaxIn1-xN alloys
Abstract
Electronic transport in unintentionally doped GaxIn1-xN alloys with various Ga concentrations (x = 0.06, 0.32 and 0.52) is studied. Hall effect measurements are performed at temperatures between 77 and 300 K. Temperature dependence of carrier mobility is analysed by an analytical formula based on two-dimensional degenerate statistics by taking into account all major scattering mechanisms for a two-dimensional electron gas confined in a triangular quantum well between GaxIn1-xN epilayer and GaN buffer. Experimental results show that as the Ga concentration increases, mobility not only decreases drastically but also becomes less temperature dependent. Carrier density is almost temperature independent and tends to increase with increasing Ga concentration. The weak temperature dependence of the mobility may be attributed to screening of polar optical phonon scattering at high temperatures by the high free carrier concentration, which is at the order of 1014 cm−2. In our analytical model, the dislocation density is used as an adjustable parameter for the best fit to the experimental results. Our results reveal that in the samples with lower Ga compositions and carrier concentrations, alloy and interface roughness scattering are the dominant scattering mechanisms at low temperatures, while at high temperatures, optical phonon scattering is the dominant mechanism. In the samples with higher Ga compositions and carrier concentrations, however, dislocation scattering becomes more significant and suppresses the effect of longitudinal optical phonon scattering at high temperatures, leading to an almost temperature-independent behaviour.</jats:p
Small Bowel Obstruction due to Mesodiverticular Band of Meckel's Diverticulum: A Case Report
Meckel's diverticulum is the most common congenital anomaly of the small intestine. Common complications related to a Meckel's diverticulum include haemorrhage, intestinal obstruction, and inflammation. Small bowel obstruction due to mesodiverticular band of Meckel's diverticulum is a rare complication. Herein, we report the diagnosis and management of a small bowel obstruction occurring due to mesodiverticular band of a Meckel's diverticulum
Excitation energy-dependent nature of Raman scattering spectrum in GaInNAs/GaAs quantum well structures
The excitation energy-dependent nature of Raman scattering spectrum, vibration, electronic or both, has been studied using different excitation sources on as-grown and annealed n- and p-type modulation-doped Ga(1 − x)In(x)N(y)As(1 − y)/GaAs quantum well structures. The samples were grown by molecular beam technique with different N concentrations (y = 0%, 0.9%, 1.2%, 1.7%) at the same In concentration of 32%. Micro-Raman measurements have been carried out using 532 and 758 nm lines of diode lasers, and the 1064 nm line of the Nd-YAG laser has been used for Fourier transform-Raman scattering measurements. Raman scattering measurements with different excitation sources have revealed that the excitation energy is the decisive mechanism on the nature of the Raman scattering spectrum. When the excitation energy is close to the electronic band gap energy of any constituent semiconductor materials in the sample, electronic transition dominates the spectrum, leading to a very broad peak. In the condition that the excitation energy is much higher than the band gap energy, only vibrational modes contribute to the Raman scattering spectrum of the samples. Line shapes of the Raman scattering spectrum with the 785 and 1064 nm lines of lasers have been observed to be very broad peaks, whose absolute peak energy values are in good agreement with the ones obtained from photoluminescence measurements. On the other hand, Raman scattering spectrum with the 532 nm line has exhibited only vibrational modes. As a complementary tool of Raman scattering measurements with the excitation source of 532 nm, which shows weak vibrational transitions, attenuated total reflectance infrared spectroscopy has been also carried out. The results exhibited that the nature of the Raman scattering spectrum is strongly excitation energy-dependent, and with suitable excitation energy, electronic and/or vibrational transitions can be investigated
Effect of angiotensin converting enzyme inhibitors on periprocedural myocardial infarction in patients with metabolic syndrome
Background: Metabolic syndrome (MetS) has been reported as a risk factor for cardiovascular events. The aim of the present study is to investigate the association between chronic angiotensin-converting enzyme inhibitors (ACE-I) therapy and the rate of periprocedural myocardial infarction (PMI) after elective coronary stenting among patients with MetS.
Methods: The inclusion criteria were MetS and plan for elective percutaneous coronary intervention. To assess the effect of ACE-I treatment on the incidence of PMI, measurements of cardiac biomarkers (CK-MB mass and troponin I) were performed at baseline and 24 h after the procedure.
Results: A total of 459 patients fulfilling the inclusion criteria were recruited to chronic ACE-I treatment and ACE-I naive groups in a 2/1 ratio. Baseline troponin I and CK-MB levels were similar in both treatment groups, whereas they were significantly lower in ACE-I group 24 h after the procedure. Univariate analysis identified body mass index (BMI), LDL cholesterol, nitrate and ACE-I use as significant factors for the development of PMI. Multivariate regression model revealed that body mass index increased and use of nitrate and ACE-I decreased the probability of PMI independent from confounding factors (OR 1.14, 95% CI 1.05–1.23, p = 0.002 for BMI; OR 0.26, 95% CI 0.14–0.48, p = 0.01 for nitrate use, OR 0.51, 95% CI 0.27–0.93, p = 0.03 for ACE-I use).
Conclusions: This prospective observational cohort trial demonstrated that chronic ACE-I therapy was an independent predictor for reduced PMI among patients with MetS who underwent elective coronary intervention
GW29-e1129 Clinical Outcomes Associated with Medical Management versus Coronary Intervention in Patients with Acute Coronary Syndrome
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The relation between endothelial dependent flow mediated dilation of the brachial artery and coronary collateral development – a cross sectional study
<p>Abstract</p> <p>Background</p> <p>Endothelial dysfunction is thought to be a potential mechanism for the decreased presence of coronary collaterals. The aim of the study was to investigate the association between systemic endothelial function and the extent of coronary collaterals.</p> <p>Methods</p> <p>We investigated the association between endothelial function assessed via flow mediated dilation (FMD) of the brachial artery following reactive hyperemia and the extent of coronary collaterals graded from 0 to 3 according to Rentrop classification in a cohort of 171 consecutive patients who had high grade coronary stenosis or occlusion on their angiograms.</p> <p>Results</p> <p>Mean age was 61 years and 75% were males. Of the 171 patients 88 (51%) had well developed collaterals (grades of 2 or 3) whereas 83 (49%) had impaired collateral development (grades of 0 or 1). Patients with poor collaterals were significantly more likely to have diabetes (<it>p </it>= 0.001), but less likely to have used statins (<it>p </it>= 0.083). FMD measurements were not significantly different among good and poor collateral groups (11.5 ± 5.6 vs. 10.4 ± 6.2% respectively, <it>p </it>= 0.214). Nitroglycerin mediated dilation was also similar (13.4 ± 5.9 vs. 12.8 ± 6.5%, <it>p </it>= 0.521).</p> <p>Conclusion</p> <p>No significant association was found between the extent of angiographically visible coronary collaterals and systemic endothelial function assessed by FMD of the brachial artery.</p
Об управлении непрофильными активами в структуре капиталов организаций
Материалы XX Междунар. науч.-техн. конф. студентов, аспирантов и молодых ученых, Гомель, 23–24 апр. 2020 г
Editor's Choice-2017 ESC Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases, in collaboration with the European Society for Vascular Surgery (ESVS)
Document covering atherosclerotic disease of extracranial carotid and vertebral, mesenteric, renal, upper and lower extremity arteries Endorsed by: the European Stroke Organization (ESO) The Task Force for the Diagnosis and Treatment of Peripheral Arterial Diseases of the European Society of Cardiology (ESC) and of the European Society for Vascular Surgery (ESVS) Authors/Task Force Members (a), Victor Aboyans (*), Jean- Baptiste Ricco (*), Marie- Louise E. L. Bartelink, Martin Bjorck, Marianne Brodmann, Tina Cohnert, Jean-Philippe Collet, Martin Czerny, Marco De Carlo, Sebastian Debus, Christine Espinola-Klein, Thomas Kahan, Serge Kownator, Lucia Mazzolai, A. Ross Naylor, Marco Roffi, Joachim Rother, Muriel Sprynger, Michal Tendera, Gunnar Tepe, Maarit Venermo, Charalambos Vlachopoulos, Ileana Desormais Document Reviewers (b), Petr Widimsky, Philippe Kolh, Stefan Agewall, Hector Bueno, Antonio Coca, Gert J. De Borst, Victoria Delgado, Florian Dick, Cetin Erol, Marc Ferrini, Stavros Kakkos, Hugo A. Katus, Juhani Knuuti, Jes Lindholt, Heinrich Mattle, Piotr Pieniazek, Massimo Francesco Piepoli, Dierk Scheinert, Horst Sievert, Iain Simpson, Jakub Sulzenko, Juan Tamargo, Lale Tokgozoglu, Adam Torbicki, Nikolaos Tsakountakis, Jose Tunon, Melina Vega de Ceniga, Stephan Windecker, Jose Luis ZamoranoPeer reviewe
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