2,939 research outputs found
Electrocardiographic Screening of Arrhythmogenic Cardiomyopathy in Genotype-Positive and Phenotype-Negative Relatives
Background: Arrhythmogenic cardiomyopathy is a hereditary cause of ventricular arrhythmias and sudden death. Identifying the healthy genetic carriers who will develop the disease remains a challenge. A novel approach to the analysis of the digital electrocardiograms of mutation carriers through signal processing may identify early electrocardiographic abnormalities.
Methods: A retrospective case–control study included a population of healthy genetics carriers and their wild-type relatives. Genotype-positive/phenotype-negative individuals bore mutations associated with the development of arrhythmogenic cardiomyopathy. The relatives included had a non-pathological 12-lead electrocardiogram, echocardiogram, and a cardiac magnetic resonance. Automatic digital electrocardiographic analyses comprised QRS and terminal activation delay duration, the number of QRS fragmentations, ST slope, and T-wave voltage.
Results: Digital 12-lead electrocardiograms from 41 genotype-positive/ phenotype-negative (29 simple carriers and 12 double mutation carriers) and 73 wild-type relatives were analyzed. No differences in the QRS length, the number of QRS fragmentations, and the voltage of the T-wave were observed. After adjusting for potential confounders, double carriers showed an average ST-slope flatter than those of the simple carriers and wild type [5.18° (0.73–8.01), 7.15° (5.14–11.05), and 11.46° (3.94–17.49), respectively, p = 0.005]. There was a significant negative correlation between the ST slope and the age in genotype-positive/phenotype-negative relatives (r = 0.376, p = 0.021) not observed in their wild-type counterparts (r = 0.074, p = 0.570).
Conclusions: A flattened ST segment may be an early sign of electrical remodeling that precedes T-wave inversion in healthy genetic carriers. A thorough analysis of the digital electrocardiographic signal may help identify and measure early electrical abnormalities
Kalman filters for leak diagnosis in pipelines: brief history and future research
The purpose of this paper is to provide a structural review of the progress made on the detection and localization of leaks in pipelines by using approaches based on the Kalman filter. To the best of the author’s knowledge, this is the first review on the topic. In particular, it is the first to try to draw the attention of the leak detection community to the important contributions that use the Kalman filter as the core of a computational pipeline monitoring system. Without being exhaustive, the paper gathers the results from different research groups such that these are presented in a unified fashion. For this reason, a classification of the current approaches based on the Kalman filter is proposed. For each of the existing approaches within this classification, the basic concepts, theoretical results, and relations with the other procedures are discussed in detail. The review starts with a short summary of essential ideas about state observers. Then, a brief history of the use of the Kalman filter for diagnosing leaks is described by mentioning the most outstanding approaches. At last, brief discussions of some emerging research problems, such as the leak detection in pipelines transporting heavy oils; the main challenges; and some open issues are addressed
Drive a Website Performance Using Web Analytics: A Case Study.
With the introduction of Web Analytics into Web Marketing, organizations now have the opportunity to measure, track, and analyze the behavior of their website users. The REAN model, standing for Reach, Engage, Activate and Nurture, appeared to be the most relevant model to plan and measure activities. This model is used to set goals, objectives and define metrics in order to improve Website performances using Web Analytics. The main research objective is to establish a list of optimization actions (based on academic papers, official sources, white papers and best practices) to be implemented, and to test if those actions had a positive impact on the website performance. Preliminary findings from this research-in-progress paper may assist managers on: 1) how to attract new visitors in order to expand traffic, 2) how to transform visitors into users, and increase registrations, and 3) how to build a loyal audience and make visitors come back
Scalable electrodeposition of liquid metal from an acetonitrile-based electrolyte for highly-integrated stretchable electronics
For the advancement of highly-integrated stretchable electronics, the
development of scalable sub-micrometer conductor patterning is required.
Eutectic gallium indium EGaIn is an attractive conductor for stretchable
electronics, as its liquid metallic character grants it high electrical
conductivity upon deformation. However, its high surface energy precludes
patterning it with (sub)-micron resolution. Herein, we overcome this limitation
by reporting for the first time the electrodeposition of EGaIn. We use a
non-aqueous acetonitrile-based electrolyte that exhibits high electrochemical
stability and chemical orthogonality. The electrodeposited material led to
low-resistance lines that remained stable upon (repeated) stretching to a 100
percent strain. Because electrodeposition benefits from the resolution of
mature nanofabrication methods used to pattern the base metal, the proposed
bottom-up approach achieved a record-high density integration of EGaIn regular
lines of 300 nm half-pitch on an elastomer substrate by plating on a gold seed
layer pre-patterned by nanoimprinting. Moreover, vertical integration was
enabled by filling high aspect ratio vias. This capability was conceptualized
by the fabrication of an omnidirectionally stretchable 3D electronic circuit,
and demonstrates a soft-electronic analogue of the stablished damascene process
used to fabricate microchip interconnects. Overall, this work proposes a simple
route to address the challenge of metallization in highly integrated (3D)
stretchable electronics.Comment: The main manuscript contains 29 pages and 5 figures. The supporting
information, attached to the document after the references, contains 8 pages
and 8 figures. The manuscript is submitted to the journal Advanced Materials.
Francisco Molina-Lopez an Jan Fransaer share the role of corresponding autho
Expression of the alpha-thionin gene from barley in tobacco confers enhanced resistance to bacterial pathogens
Thionins are cysteine-rich, 5 kDa polypeptides which are toxic to plant pathogens in vitro. Expression of the gene encoding alpha-thionin from barley endosperm, under the 35S promoter from cauliflower mosaic virus, conferred to transgenic tobacco enhanced resistance to the bacterial plant pathogens Pseudomonas syringae pv. tabaci 153 and P. syringae pv. syringae. The barley alpha-thionin gene, which has two introns, was correctly spliced in tobacco. The alpha-thionin in transgenic plants had the expected mobility in the gradient, when separated by high- performance liquid chromatography, reacted with monospecific antibodies and showed the expected antibiotic properties in vitr
The influence of history of severe periodontitis on estimated long-term marginal bone loss around implants restored with fixed segmented full-arch rehabilitation
The aim of this study was to analyze the long-term marginal bone level (MBL) of implants supporting fixed full-arch restoration in patients who had previously lost their dentition due to severe periodontitis. This retrospective study included 35 patients in whom 342 implants with internal tapered conical connections were placed. MBL was analyzed radiographically over time and a long-term estimation of MBL was calculated. A mixed linear model with abutment height, graft, diameter and location (maxilla/mandible) as factors and gender, age, implant length and prosthetic variables as covariates was used to evaluate the influence on MBL. MBL in these patients showed an estimator of predictions at 4108 days after loading of −0.307 mm, SE = 0.042. Only 0.15% of implants were radiographically affected with MBL of 3 mm or more. The mixed linear model results showed a main effect of the type of opposing dentition, gender, implant diameter, and abutment height. Particularly, an abutment height of 1 mm had associated larger MBL than the remaining heights. Thus, it can be concluded that dental implants restored with fixed segmented full-arch rehabilitation in patients with a history of severe periodontal disease do not suffer important marginal bone loss if some specific factors are considered, mainly the use of long transmucosal abutments (≥2 mm).info:eu-repo/semantics/publishedVersio
Evaluation of a dehumidifier in a mild weather greenhouse
The high humidity that surrounds crop plants, aggravated in mild weather greenhouses by high transpiration and lack of ventilation, encourages plant diseases and physiological disorders. A heat pump dehumidifier (HPD) has been installed in a mild weather greenhouse. Its development and the characteristics of the dehumidification process have been studied. The results indicate that the HPD reduced the risk of crop damage caused by humidity. Its effectiveness was related to the temperature value and the air humidity inside the greenhouse. HPD operation was not suitable under dry weather conditions. Conversely, when humidity was excessive, the HPD did not eliminate the risk of moisture damage. The appropiate conditions for using an HPD to eliminate humidity damage risk are relative humidity between 84% and 88%, and air temperature higher than 15.0 °C. Under these conditions, the condensed steam production value was 14.2 kg h−1, the specific moisture extraction rate was 2.3 kg (kW h−1), and the coefficient of performance was 2.5
Characterization and analysis of thionin genes
The general designation of thionins has been proposed for a family of homologous proteins that have been isolated from different tissues in a wide range of plant taxa and have been variously named purothionins, viscotoxins, crambins, etc. (see Garcia-Olmedo et al., 1989). The possible involvement of thionins in plant defense was first suggested, on the basis of their in vitro toxicity to plant pathogens, by Fernandez de Caleya et al., (1972). Those observations had been prompted by earlier reports concerning the antimicrobial properties of these polypeptides (Stuart and Harris, 1942; Balls and Harris, 1944). Work on the thionins, which has been actively pursued over the past half-century, has been recently reviewed in detail (Garcia-Olmedo et al., 1989). For this reason, earlier work will only be partially summarized in the present chapter, which will focus on recent developments concerning thionin genes and their potential role in plant defense mechanisms
Associations of Sedentary Behaviour, Physical Activity, Cardiorespiratory Fitness and Body Composition with Risk of Sleep-Related Breathing Disorders in Children with Overweight/Obesity: A Cross-Sectional Study
The aim of this study was to examine the associations of sedentary behaviour, physical activity, cardiorespiratory fitness (CRF), and body composition parameters with risk of sleep-related breathing disorders (SRBD) in children with overweight/obesity. One-hundred and nine children (10.0 +/- 1.1 years old, 45 girls) with overweight (n = 27) and obesity (n = 82) were included. Television viewing time was self-reported by using the Spanish adaptation of the "Youth Activity Profile" (YAP) questionnaire. Sedentary time and physical activity were measured with accelerometry. CRF was assessed with the 20-m shuttle-run test and body composition parameters with Dual-energy X-ray absorptiometry. SRBD were evaluated by using the Spanish version of the Pediatric Sleep Questionnaire. Television viewing time was positively associated with risk of SRBD (r = 0.222, p = 0.021). CRF was negatively correlated with risk of SRBD (r = -0.210, p = 0.030). Body composition parameters were positively associated with risk of SRBD (all p < 0.05), except fat mass index. Stepwise regression analyses showed that body mass index (BMI) explained the largest proportion of the variance in SRBD (r(2) = 0.063, p = 0.01) and television viewing time was the only one added after BMI (r(2) change = 0.048, p = 0.022). This study supports the notion that higher body weight status negatively influences risk of SRBD and adds that unhealthy behaviours could contribute to worsen SRBD, related to an increased risk of cardiovascular diseases. All the significant association observed in this manuscript were of small magnitude, indicating than other factors in addition to the one hereby studied contribute to explain the variance in SRBD
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