Search results for "DART"
showing 10 items of 174 documents
Evaluation of the DART 3D model in the thermal domain using satellite/airborne imagery and ground-based measurements
2011
This work provides an evaluation of the discrete anisotropy radiative transfer (DART) three-dimensional (3D) model in assessing the simulation of directional brightness temperatures (Tb) at both sensor and surface levels. Satellite imagery acquired with the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), airborne imagery acquired with the Airborne Hyperspectral Scanner (AHS) sensor and ground-based measurements collected over an agricultural area were used to evaluate the DART model at nadir views. Directional radiometric temperatures measured with a goniometric system at ground level were also used to evaluate modelling results at different view angles. The DART mod…
Preclinical atherosclerosis and metabolic syndrome increase cardio- and cerebrovascular events rate: a 20-year follow up
2013
BACKGROUND: Intima-media thickness (IMT) is a validated marker of preclinical atherosclerosis and a predictor of cardiovascular events. PATIENTS: We studied a population of 529 asymptomatic patients (age 62 ± 12.8 years), divided into two groups of subjects with and without Metabolic Syndrome (MetS). METHODS: All patients, at baseline, have had a carotid ultrasound evaluation and classified in two subgroups: the first one without atherosclerotic lesions and the second one with preclinical atherosclerosis (increased IMT or asymptomatic carotid plaque). Cardiovascular endpoints were investigated in a 20-years follow-up. RESULTS: There were 242 cardiovascular events: 144 among patients with Me…
Bispectral index changes in carotid surgery.
2010
Intraoperative monitoring of cerebral ischemia with shunting during carotid endarterectomy (CEA) remains controversial. Our objective was to evaluate the sensitivity and specificity of BIS changes during carotid clamping in relation to shunted patients in awake CEA.Eighty CEAs under cervical block were included. There were two patient groups: with clinical signs of cerebral ischemia (shunted patients) and without signs of cerebral ischemia (nonshunted patients). Data were based on bispectral index (BIS) values and neurological monitoring at different surgery time points, with special attention paid during carotid clamping. BIS values were compared between shunted and nonshunted patients. Se…
Kinking, coiling, and tortuosity of extracranial internal carotid artery: is it the effect of a metaplasia?
2006
INTRODUCTION: Morphological anomalies of the extracranial internal carotid artery (ICA) cause symptomatic cerebrovascular insufficiency in 4-16% of the cases. The aim of the present study is to evaluate macroscopic and microscopic features of a group of extracranial ICA anomalies, specifically kinking, coiling, and tortuosity, eventually affecting the surgical approach. MATERIALS AND METHODS: From January 2003 to December 2005, 10 out of 169 (6%) revascularized patients (pts) were operated upon because of an ICA anomaly. They were all but two symptomatics. Seven pts were treated by ICA transection and end-to-side reimplantation of the ICA at the level of the carotid bulb; three pts were tre…
Carotid restenosis is associated with plasma ADMA concentrations in carotid endarterectomy patients
2011
Abstract Background: The aim of this work has been to study the association between plasma asymmetric dimethylarginine (ADMA) concentrations and carotid stenosis in a group of 64 patients undergoing carotid endarterectomy (CEA). Methods: Arginine, ADMA and symmetric dimethylarginine (SDMA) were measured using capillary electrophoresis with UV detection. An evaluation of plasma concentrations of total cysteine (tCys) and total homocysteine (tHcy) was also performed. Results: Pearson’s analysis show a positive correlation between ADMA and carotid stenosis (r=0.37, p=0.003), which is also confirmed after stepwise multiple linear regression analysis. ADMA plasma concentrations were significantl…
Diagnosis and management of silent coronary ischemia in patients undergoing carotid endarterectomy.
2021
Abstract Background Coronary artery disease is the primary cause of death in patients with carotid artery disease and silent ischemia is a marker for adverse coronary events. A new noninvasive cardiac diagnostic test, coronary computed tomography-derived fractional flow reserve (FFRCT) can reliably identify ischemia-producing coronary stenosis in patients with coronary artery disease and help to select patients for coronary revascularization. The purpose of this study is to determine the prevalence of silent coronary ischemia in patients undergoing carotid endarterectomy (CEA) and to evaluate the usefulness of FFRCT in selecting patients for coronary revascularization to decrease cardiac ev…
Direct Peel Monitoring of Xenobiotics in Fruit by Direct Analysis in Real Time Coupled to a Linear Quadrupole Ion Trap–Orbitrap Mass Spectrometer
2013
Study of xenobiotics present in fruit peel by exposing it (without any pretreatment) to direct analysis in real time coupled to a high-resolution orbitrap mass spectrometer (DART-HRMS) is reported for the first time. Variables such as DART gas heater temperature and pressure, source-to-MS distance, and sample velocity are investigated. The analysis of one sample by DART-MS lasts ca. 1 min, and the benefits of both high-resolution and tandem mass spectrometry to elucidate nontarget or unknown compounds are combined. Identification of postharvest fungicides, antioxidants, and sugars in fruit peel is performed in the positive ion mode. A possible elemental formula is suggested for marker compo…
Attālinātā kontrole liela attāluma bezvadu enerģijas pārvadei izmantojot atgriezenisko saiti
2020
Attīstoties Industrija 4.0 konceptam, pieaug pieprasījums pēc bezvadu sensoriem, kas sevī ietver enerģijas avotu un bezvadu pārraides (radio) moduli. Lai nodrošinātu autonomu sensoru darbīub, nepieciešams baterejas uzlādi veikt automātiski, bez cilvēka iesaistes. Šādam mērķim lieliski strādā bezvadu enerģijas pārvades risinājumi, bet, šobdrīd tirgū pieejamais "Qi" standarts, jaudas pārvadi un komunikāciju nodrošina vien 10cm attālumā. Šī maģistra darba ietvaros tiek apskatīts "Qi" standarts, kā arī citi risinājumi, liela attāluma (>20cm) bezvadu enerģijas pārvadei, lai spriestu par to kopīgajām niansēm un nepieciešamībām, lai realizētu tāla attāluma enerģijas pārvadi. Efektīvai un drošai en…
Informācijas un komunikācijas tehnoloģiju iespējas ekonomikas pašmācības un pašpārbaudes jomā
2015
Tēmas aktualitāte pamatojama ar informācijas un komunikācijas tehnoloģiju straujo attīstību, kas piedāvā jaunas iespējas attīstīt izglītības sfēru. Darba mērķis ir, izmantojot informācijas un komunikācijas tehnoloģiju sniegtās iespējas, izveidot efektīvu pašmācības un paštestēšanas programmu, kas atbilstu vietējiem standartiem. Mērķa sasniegšanai izvirzītie uzdevumi: 1.analizēt esošos pašmācību un paštestēšanas standartus un tos aprakstīt, 2.izstrādāt un aprakstīt pašmācības un paštestēšanas programmu. Pētījumā autors atspoguļojis informāciju un komunikāciju tehnoloģiju ietekmi uz pašmācības un paštestēšanas programmām. Autors analizējis vairāku valstu akreditētu pašmācību programmu standar…
Direct analysis in real-time high-resolution mass spectrometry as a valuable tool for polyphenols profiling in olive oil
2018
A fast and reliable method to characterize the polyphenolic compound profiles in extra virgin olive oil (EVOO) has been developed using direct analysis in real time (DART) and linear ion-trap Orbitrap mass spectrometry (LTQ-Orbitrap-MS). Hydroalcoholic extraction increased speed and reduced matrix effects, and DART-MS/MS ensured accurate analysis. Characterization of polyphenol fingerprinting in EVOO samples takes 2 min. This method exhibited proper linearity (R2 ≥ 0.99) in the range of 5–2500 μg g−1, limit of detection (LOD) of 1.5 μg g−1 (signal-to noise S/N = 3), and limits of quantitation (LOQs) of 5 μg g−1 (S/N = 10) for resveratrol (a polyphenol not detected in olive oil). Six spiked …