Исследование влияния поляризации на метрологические характеристики сенсора кислорода

В роботі проводилося дослідження різних чинників, які впливають на метрологічні характеристики сенсору. Підвищення метрологічних характеристик приладів може бути досягнуто при використанні імпульсних методів поляризації електродів сенсорів. Новизна роботи полягає в застосуванні імпульсної поляризації сенсорів кисню та розробці нових методів обробки вихідних сигналів з метою підвищення метрологічних характеристик приладів. Досліджено кінетику процесів відновлення кисню на катодах сенсорів при поляризації імпульсною напругою. Застосування нових методів поляризації приводить до мінімального впливу роботи сенсора на рівноважні процеси в біологічних об’єктах, що підвищує точність вимірювання та забезпечує швидку реакцію приладу на зміну впливу зовнішніх чинників.The research of different factors influencing on the metrological characteristics of the sensor was conducted in the paper. The elevation of the devices’ metrological characteristics can be achieved by using pulsed methods of polarization of sensors’ electrodes. Novelty of work consists in application of pulse polarization of sensors of oxygen and development of new methods of processing of target signals for the purpose of increase of metrological characteristics of devices. Kinetics of the processes of oxygen reduction on sensors’ cathode under polarization of the pulse voltage is researched. Application of the new methods of polarization leads to minimal influence on the work of sensor on equilibrium processes in biological objects which increases accuracy of measurement and provides quick reaction of the device on the alteration of the effect of external factors.В работе проводились исследования различных факторов, влияющих на метрологические характеристики сенсора. Повышение метрологических характеристик приборов может быть достигнуто при использовании импульсных методов поляризации электродов сенсоров. Новизна работы заключается в применении импульсной поляризации сенсоров кислорода и разработке новых методов обработки выходных сигналов с целью повышения метрологических характеристик приборов. Исследована кинетика процессов восстановления кислорода на катодах сенсоров при поляризации импульсным напряжением. Применение новых методов поляризации приводит к минимальному влиянию работы сенсора на равновесные процессы в биологических объектах, что повышает точность измерения и обеспечивает быструю реакцию прибора на изменение воздействия внешних факторов

Fast Fencing

We consider very natural "fence enclosure" problems studied by Capoyleas, Rote, and Woeginger and Arkin, Khuller, and Mitchell in the early 90s. Given a set $S$ of $n$ points in the plane, we aim at finding a set of closed curves such that (1) each point is enclosed by a curve and (2) the total length of the curves is minimized. We consider two main variants. In the first variant, we pay a unit cost per curve in addition to the total length of the curves. An equivalent formulation of this version is that we have to enclose $n$ unit disks, paying only the total length of the enclosing curves. In the other variant, we are allowed to use at most $k$ closed curves and pay no cost per curve. For the variant with at most $k$ closed curves, we present an algorithm that is polynomial in both $n$ and $k$. For the variant with unit cost per curve, or unit disks, we present a near-linear time algorithm. Capoyleas, Rote, and Woeginger solved the problem with at most $k$ curves in $n^{O(k)}$ time. Arkin, Khuller, and Mitchell used this to solve the unit cost per curve version in exponential time. At the time, they conjectured that the problem with $k$ curves is NP-hard for general $k$. Our polynomial time algorithm refutes this unless P equals NP

Fast Fencing

International audienceWe consider very natural ”fence enclosure” problems studied by Capoyleas, Rote, and Woeginger and Arkin, Khuller, and Mitchell in the early 90s. Given a set S of n points in the plane, we aim at finding a set of closed curves such that (1) each point is enclosed by a curve and (2) the total length of the curves is minimized. We consider two main variants. In the first variant, we pay a unit cost per curve in addition to the total length of the curves. An equivalent formulation of this version is that we have to enclose n unit disks, paying only the total length of the enclosing curves. In the other variant, we are allowed to use at most k closed curves and pay no cost per curve.For the variant with at most k closed curves,we present an algorithm that is polynomialin bothn andk. For the variant with unit cost per curve, or unit disks, we presenta near-linear time algorithm.Capoyleas, Rote, and Woeginger solved the problem with at most k curves in nO(k) time. Arkin, Khuller, and Mitchell used this to solve the unit cost per curve version in exponential time. At the time, they conjectured that the problem with k curves is NP-hard for general k. Our polynomial time algorithm refutes this unless P equals NP

Defending Financial Infrastructures Through Early Warning Systems: The intelligence cloud approach

Recent evidence of successful Internet-based attacks and frauds involvingnancial institutions highlights the inadequacy of the existing protection mechanisms, in which each instutition implements its own isolated monitoring and reaction strategy. Analyzing on-line activity and detecting attacks on a large scale is an open issue due to the huge amounts of events that should be collected and processed. In this paper, we propose a large-scale distributed event processing system, called intelligence cloud, allowing the nancial entities to participate in a widely distributed monitoring and detection effort through the exchange and processing of information locally available at each participating site. We expect this approach to be able to handle large amounts of events arriving at high rates from multiple domains of the financial scenario. We describe a framework based on the intelligence cloud where each participant can receive early alerts enabling them to deploy proactive countermeasures and mitigation strategies. Copyright © 2009 ACM

Pioglitazone modulates vascular inflammation in atherosclerotic rabbits : noninvasive assessment with FDG-PET-CT and dynamic contrast-enhanced MR imaging

Objectives We sought to determine the antiatherosclerotic properties of pioglitazone using multimethod noninvasive imaging techniques. Background Inflammation is an essential component of vulnerable or high-risk atheromas. Pioglitazone, a peroxisome proliferator-activated receptor-gamma agonist, possesses potent anti-inflammatory properties. We aimed to quantify noninvasively the anti-inflammatory effects of pioglitazone on atheroma using 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography (PET)/computed tomography (CT) and dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI). Methods Atherosclerotic plaques were induced in the aorta of 15 New Zealand white rabbits by a combination of a hyperlipidemic diet and 2 balloon endothelial denudations. Nine rabbits continued the same diet, whereas 6 rabbits received pioglitazone (10 mg/kg orally) in addition to the diet. Twelve animals underwent 18F-FDG-PET/CT, and 15 animals underwent DCE-MRI at baseline, 1 month, and 3 months after treatment initiation. Concomitantly, serum metabolic parameters were monitored. After imaging was completed, aortic histologic analysis and correlation analysis were performed. Results The 18F-FDG-PET/CT imaging detected an increase in average standardized uptake value in the control group (p <0.01), indicating progressive inflammation, whereas stable standardized uptake values were observed in the treatment group, indicating no progression. The DCE-MRI analysis detected a significant decrease in the area under the curve for the pioglitazone group (p <0.01). Immunohistologic examination of the aortas demonstrated a significant decrease in macrophage and oxidized phospholipid immunoreactivity in the pioglitazone group (p = 0.04 and p = 0.01, respectively) with respect to control animals, underlining the imaging results. Serum metabolic parameters showed no difference between groups. Strong positive correlations between standardized uptake value and macrophage density and between area under the curve and neovessels were detected (r2 = 0.86 and p <0.0001, and r2 = 0.66 and p = 0.004, respectively). Conclusions Both 18F-FDG-PET/CT and DCE-MRI demonstrate noninvasively the anti-inflammatory effects of pioglitazone on atheroma. Both imaging methods seem suited to monitor inflammation in atherosclerosis

Gallium-68 DOTATATE PET in the Evaluation of Intracranial Meningiomas.

BACKGROUND AND PURPOSE: Meningiomas are the most common primary intracranial tumors, typically treated with surgery and adjuvant radiation in cases of subtotal resection and/or higher histopathologic grade. Contrast-enhanced magnetic resonance imaging (MRI) is the gold standard for postoperative assessment and adjuvant treatment planning. However, MRI can have limited accuracy particularly in the presence of posttreatment change. [68Ga]-DOTATATE is a Positron Emission Tomography (PET) radiotracer targeting somatostatin receptor 2A (SSTR2A). SSTR2A is a reliable biomarker of meningiomas. We report a consecutive case series of 20 patients evaluated with [68Ga]-DOTATATE PET/MRI, propose a novel approach to quantitative analysis, and discuss clinical implications. METHODS: We present a consecutive case series of 20 patients with clinically suspected or pathology-proven meningioma evaluated between July 2018 and February 2019. [68Ga]-DOTATATE PET/MRI was obtained in order to confirm the diagnosis or determine tumor recurrence/progression to help guide surgical and/or radiation therapy management in cases in which MRI findings were indeterminate or equivocal. RESULTS: Seventeen (85%) patients had undergone prior surgery and 11 (55%) underwent adjuvant radiation therapy. In 17 patients [68Ga]-DOTATATE confirmed the presence of recurrent meningioma. A total of 49 meningiomas were identified (median: 2 meningiomas/patient, range 0-14). There was excellent differentiation between meningioma and posttreatment change based on our approach of target lesion/superior sagittal sinus maximum standardized uptake values ratio (16.6 vs. 1.6, P \u3c .0001). CONCLUSIONS: [68Ga]-DOTATATE PET/MRI is a promising tool in the assessment of both treatment naïve and resected/irradiated meningiomas, allowing improved diagnosis and extent of disease evaluation. Future prospective studies are needed to determine utility of [68Ga]-DOTATATE PET/MRI in treatment response assessment

Severe Acute Hepatocellular Injury Attributed to OxyELITE Pro: A Case Series

BACKGROUND/AIMS: Herbal and dietary supplement (HDS) hepatotoxicity is increasingly being reported in the United States. This case series describes the presenting clinical features and outcomes of 7 patients with liver injury attributed to OxyELITE Pro enrolled in the Drug Induced Liver Injury Network (DILIN) study. METHODS: The 6 month outcomes of patients with hepatotoxicity attributed to OxyELITE Pro enrolled in the DILIN prospective registry between 2004 and 2015 are presented. RESULTS: Six of the 7 patients (86%) presented in 2013 with symptoms of hepatitis and acute hepatocellular injury. The median duration of OxyELITE Pro use was 18 weeks (range: 5 to 102 weeks). Median age was 36 years (range: 28 to 62), 86% were female, and 43% were Asian. One patient had rash, none had eosinophilia and 3 had antinuclear antibody reactivity. The median peak ALT was 2242 U/L, alkaline phosphatase 284 U/L and bilirubin 15.0 mg/dL. Six patients (86%) were hospitalized, 3 developed acute liver failure and 2 underwent liver transplantation. DILIN causality scores for OxyELITE Pro were definite in 1, highly likely in 3, probable in 2, and possible in 1. Four of the 5 patients without liver transplant recovered completely within 6 months while one patient had mild residual ALT elevations. CONCLUSIONS: Seven cases of severe acute hepatocellular injury attributed to OxyELITE Pro are reported. These results reinforce the need to assess for HDS supplement use in patients presenting with unexplained acute hepatitis and point to the need for additional regulatory oversight of HDS products