319 research outputs found

    A Novel Low-Cost Sensor Prototype for Nocturia Monitoring in Older People

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    Indexación: Scopus.This work was supported in part by CORFO - CENS 16CTTS-66390 through the National Center on Health Information Systems, in part by the National Commission for Scientific and Technological Research (CONICYT) through the program STIC-AMSUD 17STIC-03: ‘‘e-MONITOR âĂŞ Chronic Disease: Ambient Assisted Living and vital teleMONOTORing for e-health,’’ FONDEF ID16I10449 ‘‘Sistema inteligente para la gestión y análisis de la dotación de camas en la red asistencial del sector público,’’ and MEC80170097 ‘‘Red de colaboración científica entre universidades nacionales e internacionales para la estructuración del doctorado y magister en informática médica en la Universidad de Valparaíso.’’ The work of V. H. C. de Albuquerque was supported by the Brazilian National Council for Research and Development (CNPq) under Grant #304315/2017-6.Nocturia is frequently defined as the necessity to get out of bed at least one time during the night to urinate, with each of these episodes being preceded and continued by sleep. Several studies suggest that an increase of nocturia is seen with the onset of age, occurring in around 70% of adults over the age of 70. Its appearance is associated with detrimental quality of life for those who present nocturia, since it leads to daytime sleepiness, cognitive dysfunction, among others. Currently, a voiding diary is necessary for nocturia assessment; these are prone to bias due to their inherent subjectivity. In this paper, we present the design of a low-cost device that automatically detects micturition events. The device obtained 73% in sensibility and 81% in specificity; these results show that systems such as the proposed one can be a valuable tool for the medical team when evaluating nocturia. © 2013 IEEE.https://ieeexplore.ieee.org/document/845445

    A novel monitoring system for fall detection in older people

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    Indexación: Scopus.This work was supported in part by CORFO - CENS 16CTTS-66390 through the National Center on Health Information Systems, in part by the National Commission for Scientific and Technological Research (CONICYT) through the Program STIC-AMSUD 17STIC-03: ‘‘MONITORing for ehealth," FONDEF ID16I10449 ‘‘Sistema inteligente para la gestión y análisis de la dotación de camas en la red asistencial del sector público’’, and in part by MEC80170097 ‘‘Red de colaboración científica entre universidades nacionales e internacionales para la estructuración del doctorado y magister en informática médica en la Universidad de Valparaíso’’. The work of V. H. C. De Albuquerque was supported by the Brazilian National Council for Research and Development (CNPq), under Grant 304315/2017-6.Each year, more than 30% of people over 65 years-old suffer some fall. Unfortunately, this can generate physical and psychological damage, especially if they live alone and they are unable to get help. In this field, several studies have been performed aiming to alert potential falls of the older people by using different types of sensors and algorithms. In this paper, we present a novel non-invasive monitoring system for fall detection in older people who live alone. Our proposal is using very-low-resolution thermal sensors for classifying a fall and then alerting to the care staff. Also, we analyze the performance of three recurrent neural networks for fall detections: Long short-term memory (LSTM), gated recurrent unit, and Bi-LSTM. As many learning algorithms, we have performed a training phase using different test subjects. After several tests, we can observe that the Bi-LSTM approach overcome the others techniques reaching a 93% of accuracy in fall detection. We believe that the bidirectional way of the Bi-LSTM algorithm gives excellent results because the use of their data is influenced by prior and new information, which compares to LSTM and GRU. Information obtained using this system did not compromise the user's privacy, which constitutes an additional advantage of this alternative. © 2013 IEEE.https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=842305

    Ein aktiver und stabiler Cobaltkatalysator für die Sauerstoffentwicklungsreaktion: Polymerisation einer ionischen Flüssigkeit

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    Inspiriert durch die katalytischen Eigenschaften von Single-site-Katalysatoren und der erhöhten Leistungsfähigkeit von Metallkatalysatoren durch ionische Flüssigkeiten wurde eine Methode zur gezielten und skalierbaren Platzierung von einzelnen Cobaltatomen auf Kohlenstoffnanoröhrenoberflächen mithilfe einer polymerisierten ionischen Flüssigkeit entwickelt. Durch eine ionische Flüssigkeit wurden einzelne, fein verteilte Cobaltionen koordiniert und als heterogener Katalysator für die Sauerstoffententwicklungsreaktion (OER) genutzt. Die erhaltenen Daten zeigen eine hohe Aktivität bei gleichzeitig vorhandener Stabilität

    Optimal opportunistic screening of atrial fibrillation using pulse palpation in cardiology outpatient clinics: Who and how

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    Atrial fibrillation (AF) remain a prevalent undiagnosed condition frequently encountered in primary care.We aimed to find the parameters that optimize the diagnostic accuracy of pulse palpation to detect AF. We also aimed to create a simple algorithm for selecting which individuals would benefit from pulse palpation and, if positive, receive an ECG to detect AF.Nurses from four Cardiology outpatient clinics palpated 7,844 pulses according to a randomized list of arterial territories and durations of measure and immediately followed by a 12-lead ECG, which we used as the reference standard. We calculated the sensitivity and specificity of the palpation parameters. We also assessed whether diagnostic accuracy depended on the nurse's experience or on a list of clinical factors of the patients. With this information, we estimated the positive predictive values and false omission rates according to very few clinical factors readily available in primary care (age, sex, and diagnosis of heart failure) and used them to create the algorithm.The parameters associated with the highest diagnostic accuracy were palpation of the radial artery and classifying as irregular those palpations in which the nurse was uncertain about pulse regularity or unable to palpate pulse (sensitivity = 79%; specificity = 86%). Specificity decreased with age. Neither the nurse's experience nor any investigated clinical factor influenced diagnostic accuracy. We provide the algorithm to select the ≥40 years old individuals that would benefit from a pulse palpation screening: a) do nothing in <60 years old individuals without heart failure; b) do ECG in ≥70 years old individuals with heart failure; c) do radial pulse palpation in the remaining individuals and do ECG if the pulse is irregular or you are uncertain about its regularity or unable to palpate it.Opportunistic screening for AF using optimal pulse palpation in candidate individuals according to a simple algorithm may have high effectiveness in detecting AF in primary care

    Razvoj i validacija spektrofotometrijskih metoda za određivanje ceftazidima u farmaceutskim doziranim pripravcima

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    Two spectrophotometric methods for the determination of ceftazidime (CFZM) in either pure form or in its pharmaceutical formulations are described. The first method is based on the reaction of 3-methylbenzothiazolin-2-one hydrazone (MBTH) with ceftazidime in the presence of ferric chloride in acidic medium. The resulting blue complex absorbs at λmax 628 nm. The second method describes the reaction between the diazotized drug and N-(1-naphthyl)ethylenediamine dihydrochloride (NEDA) to yield a purple colored product with λmax at 567 nm. The reaction conditions were optimized to obtain maximum color intensity. The absorbance was found to increase linearly with increasing the concentration of CFZM; the systems obeyed the Beer’s law in the range 210 and 1050 µg mL1 for MBTH and NEDA methods, respectively. LOD, LOQ and correlation coefficient values were 0.15, 0.79 and 0.50, 2.61. No interference was observed from common excipients present in pharmaceutical formulations. The proposed methods are simple, sensitive, accurate and suitable for quality control applications.Razvijene su dvije spektrofotometrijske metode za određivanje ceftazidima (CFZM), čistog ili u farmaceutskim pripravcima. Prva metoda se temelji na reakciji 3-metilbenzotiazolin-2-on hidrazona (MBTH) sa ceftazidimom u prisutnosti željezovog(III) klorida u kiselom mediju. Nastaje plavi kompleks s maksimumom apsorpcije pri λmax 628 nm. Druga metoda se temelji na reakciji između diazotiranog lijeka i N-(1-naftil)etilendiamin dihidroklorida (NEDA), pri čemu nastaje ljubičasti produkt s λmax pri 567 nm. Reakcijski uvjeti su optimirani da se dobije maksimalni intenzitet boje. Apsorbancija raste linearno s porašću koncentracije CFZM; sustavi slijede Beerov zakon u koncentracijskom području 210 za MBTH metodu i 1050 µg mL1 za NEDA metodu. LOD i LOQ te vrijednosti korelacijskog koeficijenta su 0,15, 0,79 i 0,50, 2,61. Uobičajene pomoćne tvari ne smetaju određivanju ceftazidima. Predložene metode su jednostavne, osjetljive, točne i pogodne za primjenu u kontroli kvalitete

    Muon-induced background in the EDELWEISS dark matter search

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    A dedicated analysis of the muon-induced background in the EDELWEISS dark matter search has been performed on a data set acquired in 2009 and 2010. The total muon flux underground in the Laboratoire Souterrain de Modane (LSM) was measured to be Φμ=(5.4±0.20.9+0.5)\Phi_{\mu}=(5.4\pm 0.2 ^{+0.5}_{-0.9})\,muons/m2^2/d. The modular design of the muon-veto system allows the reconstruction of the muon trajectory and hence the determination of the angular dependent muon flux in LSM. The results are in good agreement with both MC simulations and earlier measurements. Synchronization of the muon-veto system with the phonon and ionization signals of the Ge detector array allowed identification of muon-induced events. Rates for all muon-induced events Γμ=(0.172±0.012)evts/(kgd)\Gamma^{\mu}=(0.172 \pm 0.012)\, \rm{evts}/(\rm{kg \cdot d}) and of WIMP-like events Γμn=0.0080.004+0.005evts/(kgd)\Gamma^{\mu-n} = 0.008^{+0.005}_{-0.004}\, \rm{evts}/(\rm{kg \cdot d}) were extracted. After vetoing, the remaining rate of accepted muon-induced neutrons in the EDELWEISS-II dark matter search was determined to be Γirredμn<6104evts/(kgd)\Gamma^{\mu-n}_{\rm irred} < 6\cdot 10^{-4} \, \rm{evts}/(\rm{kg \cdot d}) at 90%\,C.L. Based on these results, the muon-induced background expectation for an anticipated exposure of 3000\,\kgd\ for EDELWEISS-3 is N3000kgdμn<0.6N^{\mu-n}_{3000 kg\cdot d} < 0.6 events.Comment: 21 pages, 16 figures, Accepted for publication in Astropart. Phy

    Metal organic framework nanosheets in polymer composite materials for gas separation

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    [EN] Composites incorporating two-dimensional nanostructures within polymeric matrices have potential as functional components for several technologies, including gas separation. Prospectively, employing metal-organic frameworks (MOFs) as versatile nanofillers would notably broaden the scope of functionalities. However, synthesizing MOFs in the form of freestanding nanosheets has proved challenging. We present a bottom-up synthesis strategy for dispersible copper 1,4-benzenedicarboxylate MOF lamellae of micrometre lateral dimensions and nanometre thickness. Incorporating MOF nanosheets into polymer matrices endows the resultant composites with outstanding CO2 separation performance from CO2/CH4 gas mixtures, together with an unusual and highly desired increase in the separation selectivity with pressure. As revealed by tomographic focused ion beam scanning electron microscopy, the unique separation behaviour stems from a superior occupation of the membrane cross-section by the MOF nanosheets as compared with isotropic crystals, which improves the efficiency of molecular discrimination and eliminates unselective permeation pathways. This approach opens the door to ultrathin MOF-polymer composites for various applications.The research leading to these results has received funding (J.G., B.S.) from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013)/ERC Grant Agreement no. 335746, CrystEng-MOF-MMM. T.R. is grateful to TUDelft for funding. G.P. acknowledges the A. von Humboldt Foundation for a research grant. A.C., I.L. and F.X.L.i.X. thank Consolider-Ingenio 2010 (project MULTICAT) and the ‘Severo Ochoa’ programme for support. 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    Chaos for the Hyperbolic Bioheat Equation

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    The Hyperbolic Heat Transfer Equation describes heat processes in which extremely short periods of time or extreme temperature gradients are involved. It is already known that there are solutions of this equation which exhibit a chaotic behaviour, in the sense of Devaney, on certain spaces of analytic functions with certain growth control. We show that this chaotic behaviour still appears when we add a source term to this equation, i.e. in the Hyperbolic Bioheat Equation. These results can also be applied for the Wave Equation and for a higher order version of the Hyperbolic Bioheat Equation.The authors are supported in part by MEC and FEDER, Projects MTM2010-14909 and MTM2013-47093-P.Conejero, JA.; Ródenas Escribá, FDA.; Trujillo Guillen, M. (2015). Chaos for the Hyperbolic Bioheat Equation. Discrete and Continuous Dynamical Systems - Series A. 35(2):653-668. doi:10.3934/dcds.2015.35.653S65366835
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