123 research outputs found

    Automatic recognition of retinal diseases using mathematical models of image processing, based on multilayer-dictionary learning

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    Background and Objective:Image processing is one of the most important issues in the field of artificial intelligence, which is used in various industrial, medical, military, and security systems. One of the most important applications of image processing is the extraction of different types of classification in the field of medical sciences. By using powerful algorithms in this field, intelligent systems can be invented that automatically understand and interpret the medical characteristics of individuals without the need to the physician supervision can discover useful information to help experts make good judgments. When the necessary parameters for the diagnosis of the disease increase, the diagnosis and prognosis of the disease becomes very difficult even for an expert, which is why computer diagnostic tools have been used in recent decades to help the physicians. This has led to a reduction in possible errors due to fatigue or inexperience of the specialist, and to provide the required medical data to the physician in less time and with more detail and accuracy. The purpose of this study is to improve the classification of new methods using a multi-layered model to address retinal diseases diagnosis. Methods: This paper presents a multi-layer dictionary learning method for classification tasks.  Our multi-layer framework uses a label consistent in K-SVD algorithm to learn a discriminative dictionary for sparse coding in order to learn better features in retinal optical coherence tomography images. In addition to using class labels of training data, we also associate label information with each dictionary item (columns of the dictionary matrix) to enforce discrimination in sparse codes during dictionary learning process. In fact, it relies on a succession of sparse coding and pooling steps in order to find an effective representation of data for classification. Moreover, we apply Duke dataset for validating our algorithm: Duke spectral domain OCT (SD-OCT) dataset, consisting of volumetric scans acquired from 45 subjects 15 normal subjects, 15 AMD patients, and 15 DME patients. Findings: Our classifier leads to a correct classification rate of 95.85% and 100.00% for normal and abnormal (DME and AMD). Experimental results demonstrate that our algorithm outperforms compared to many recent proposed supervised dictionary learning and sparse representation techniques. Conlusion: The results of this study were to provide an automatic system for the diagnosis of some retinal abnormalities in a way that it could do data analysis with high accuracy in comparison to other modern methods to diagnosis delicate patterns of OCT, separate images of normal and patient the normal and in two age-related macular degeneration diseases (AMD), and diabetic macular degeneration (DME), and help the physician to diagnose retinal pathology with great care. As a suggestion for professionals and future research, by generalizing this method to the more classes, we can cover the entire retinal myopia and use it as a potentially effective tool in computerized diagnosis and screening for retinal disease or in the wider eye area.   ===================================================================================== COPYRIGHTS  ©2019 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

    The contribution of the Chirality-Induced Spin Selectivity (CISS) effect to the dispersion interaction between chiral molecules

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    Dispersion interactions are one of the components of van der Waals forces, which play a key role in the understanding of intermolecular interactions in many physical, chemical and biological processes. The theory of dispersion forces was developed by London in the early years of quantum mechanics. However, it was only in the 1960s that it was recognized that for molecules lacking an inversion center such as chiral and helical molecules, there are chirality-sensitive corrections to the dispersion forces proportional to the rotatory power known from the theory of circular dichroism and with the same distance scaling law R-6 as the London energy. The discovery of the Chirality-Induced Spin Selectivity (CISS) effect in recent years has led to an additional twist in the study of chiral molecular systems, showing a close relation between spin and molecular geometry. Motivated by it, we propose in this investigation that there may exist additional contributions to the dispersion energy related to intermolecular, induced spin-orbit (ISOC) interactions. Within a second-order perturbative approach, these forces manifest as an effective intermolecular spin-spin exchange interaction. Although they are weaker than the standard London forces, the ISOC interactions turn out to be nevertheless not negligible and display the same R6^{-6} distance scaling. Our results suggest that classical force field descriptions of van-der Waals interactions may require additional modifications to include the effects discussed here.Comment: 21 pages, 2 figure

    Toward a Control Oriented Model of Xerographic Marking Engines

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    This paper presents some preliminary results from a research collaboration concerning the modeling and control of color xerography. In this first communication of our work, we describe our efforts to develop a model for a monochrome marking engine. We adopt the technique of principal component analysis for choice of output coordinates and demonstrate preliminary experimental evidence suggesting that this procedure yields accuracy in data reconstruction superior to present industry practice. Preliminary analysis of the experimental evidence suggests that the process has a nonlinear component that we seek to model using a mixture of physical and empirical insight

    Effect of milrinone on short-term outcome of patients with myocardial dysfunction undergoing coronary artery bypass graft: A randomized controlled trial

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    Background: Myocardial dysfunction needing inotropic support is a typical complication after on-pump cardiac surgery. In this study, we evaluate the effect of milrinone on patients with ventricular dysfunction undergoing coronary artery bypass graft (CABG). Methods: Seventy patients with impaired left ventricular function [left ventricular ejection fraction (LVEF) < 35%] undergoing on-pump CABG were enrolled. Patients were randomized to receive either an intraoperative bolus of milrinone (50 &#956;g/kg) or saline as placebo followed by a 24-hour infusion of each agent (0.5 &#956;g/kg/min). Hemodynamic parameters and transthoracic echocardiographic measurement of systolic and diastolic functions were the variables evaluated. Results: Serum levels of creatine phosphokinase (CPK), the MB isoenzyme of creatine kinase (CK-MB), occurrence of myocardial ischemia or infarction, and mean duration of using inotropic agents were significantly lower in the milrinone group (p < 0.05). There were no significant differences between the two groups regarding the development of ventricular arrhythmia, duration of cardiopulmonary bypass, intra-aortic balloon pump and inotropic support requirement, duration of mechanical ventilation, duration of intensive care unit stay and mortality rate. Although mean pre-operative LVEF was significantly lower in the milrinone group, there was no significant difference between post-operative LVEFs. Conclusions: We suggest that perioperative administration of milrinone in patients undergoing on-pump CABG, especially those with low LVEF, is beneficial. (Cardiol J 2010; 17, 1: 73-78

    Fully sp²‐carbon‐linked crystalline two‐dimensional conjugated polymers: insight into 2D poly(phenylenecyanovinylene) formation and their optoelectronic properties

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    Cyano‐substituted polyphenylene vinylenes (PPVs) have been in the focus of research for several decades due to their interesting optoelectronic properties and potential applications in organic electronics. With the advent of organic two‐dimensional (2D) crystals, the question arose how the chemical and optoelectronic advantages of PPVs evolve in 2D compared to their linear counterparts. In this work, we present the efficent synthesis of two novel 2D fully sp²‐carbon‐linked crystalline PPVs and investigate the essentiality of inorganic bases for their catalytic formation. Notably, among all bases screened, cesium carbonate (Cs₂CO₃) plays a crucial role and enables reversibility in the first step with subsequent structure locking by formation of a C=C double bond to maintain crystallinity, which is supported by density functional theory (DFT) calculation. We propose a quantifiable energy diagram of a “quasi‐reversible reaction” which allows to identify further suitable C‐C bond formation reactions for 2D polymerizations. Moreover, we delineate the narrowing of the HOMO‐LUMO gap by expanding conjugation into two dimensions. To enable environmentally benign processing, we further perform the post‐modification of 2D PPVs, which renders stable dispersions in the aqueous phase

    Modulation of LXR signaling altered the dynamic activity of human colon adenocarcinoma cancer stem cells in vitro

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    Background: The expansion and metastasis of colorectal cancers are closely associated with the dynamic growth of cancer stem cells (CSCs). This study aimed to explore the possible effect of LXR (a regulator of glycolysis and lipid hemostasis) in the tumorgenicity of human colorectal CD133 cells. Methods: Human HT-29 CD133+ cells were enriched by MACS and incubated with LXR agonist (T0901317) and antagonist (SR9243) for 72 h. Cell survival was evaluated using MTT assay and flow cytometric analysis of Annexin-V. The proliferation rate was measured by monitoring Ki-67 positive cells using IF imaging. The modulation of LXR was studied by monitoring the activity of all factors related to ABC transporters using real-time PCR assay and western blotting. Protein levels of metabolic enzymes such as PFKFB3, GSK3β, FASN, and SCD were also investigated upon treatment of CSCs with LXR modulators. The migration of CSCs was monitored after being exposed to LXR agonist using scratch and Transwell insert assays. The efflux capacity was measured using hypo-osmotic conditions. The intracellular content of reactive oxygen species was studied by DCFH-DA staining. Results: Data showed incubation of CSCs with T0901317 and SR9243 reduced the viability of CD133 cells in a dose-dependent manner compared to the control group. The activation of LXR up-regulated the expression and protein levels of ABC transporters (ABCA1, ABCG5, and ABCG8) compared to the non-treated cells (p < 0.05). Despite these effects, LXR activation suppressed the proliferation, clonogenicity, and migration of CD133 cells, and increased hypo-osmotic fragility (p < 0.05). We also showed that SR9243 inhibited the proliferation and clonogenicity of CD133 cells through down-regulating metabolic enzymes PFKFB3, GSK3β, FASN, and SCD as compared with the control cells (p < 0.05). Intracellular ROS levels were increased after the inhibition of LXR by SR9243 (p < 0.05). Calling attention, both T0901317 and SR9243 compounds induced apoptotic changes in cancer stem cells (p < 0.05). Conclusions: The regulation of LXR activity can be considered as a selective targeting of survival, metabolism, and migration in CSCs to control the tumorigenesis and metastasis in patients with advanced colorectal cancers

    Visual change detection on tunnel linings

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    We describe an automated system for detecting, localising, clustering and ranking visual changes on tunnel surfaces. The system is designed to provide assistance to expert human inspectors carrying out structural health monitoring and maintenance on ageing tunnel networks. A three-dimensional tunnel surface model is first recovered from a set of reference images using Structure from Motion techniques. New images are localised accurately within the model and changes are detected versus the reference images and model geometry. We formulate the problem of detecting changes probabilistically and evaluate the use of different feature maps and a novel geometric prior to achieve invariance to noise and nuisance sources such as parallax and lighting changes. A clustering and ranking method is proposed which efficiently presents detected changes and further improves the inspection efficiency. System performance is assessed on a real data set collected using a low-cost prototype capture device and labelled with ground truth. Results demonstrate that our system is a step towards higher frequency visual inspection at a reduced cost.The authors gratefully acknowledge the support by Toshiba Research Europe.This is the accepted manuscript. The final publication is available at Springer via http://dx.doi.org/10.1007/s00138-014-0648-8

    Wpływ stosowania milrinonu na wczesne wyniki leczenia pacjentów z dysfunkcją mięśnia sercowego poddawanych pomostowaniu aortalno-wieńcowemu: badanie kontrolowane z randomizacją

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    Wstęp: Dysfunkcja mięśnia sercowego wymagająca stosowania leczenia inotropowego jest częstym powikłaniem zabiegów kardiochirurgicznych z wykorzystaniem krążenia pozaustrojowego. W niniejszym badaniu podjęto próbę oceny wpływu stosowania milrinonu u pacjentów z nieprawidłową czynnością mięśnia sercowego, poddawanych pomostowaniu aortalno-wieńcowemu. Metody: Do badania włączono 70 pacjentów z upośledzoną funkcją lewej komory (frakcja wyrzutowa lewej komory - LVEF < 35%), u których wykonano pomostowanie aortalno-wieńcowe. Zostali oni losowo podzieleni na dwie grupy. Osoby z jednej z nich otrzymywały w trakcie operacji milrinon w bolusie (50 &#956;g/kg mc.), natomiast chorzy z drugiej grupy roztwór soli fizjologicznej jako placebo. Następnie w każdej grupie zastosowano 24-godzinny wlew wcześniej podanej substancji w przepływie 0,5 &#956;g/kg mc./min. Analizie poddano dane hemodynamiczne oraz pomiary skurczowej i rozkurczowej funkcji serca uzyskane podczas echokardiografii przezklatkowej. Wyniki: Osoczowe stężenie kinazy fosfokreatynowej (CPK), izoenzymu MB kinazy kreatynowej (CK-MB), częstość występowania niedokrwienia lub zawału serca oraz średni czas leczenia inotropowego były znacząco niższe w grupie pacjentów otrzymujących milrinon (p < 0,05). Nie stwierdzono istotnych różnic między grupami w występowaniu arytmii komorowych, długości trwania krążenia pozaustrojowego i wentylacji mechanicznej, konieczności stosowania kontrapulsacji wewnątrzaortalnej i leczenia inotropowego, długości pobytu na oddziale intensywnej opieki medycznej oraz śmiertelności. Mimo że średnia LVEF była istotnie niższa u pacjentów otrzymujących milrinon, nie stwierdzono istotnych różnic w średniej LVEF w pooperacyjnej obserwacji badanych grup. Wnioski: Okołooperacyjne stosowanie milrinonu jest korzystne u pacjentów poddawanych pomostowaniu aortalno-wieńcowemu z wykorzystaniem krążenia pozaustrojowego, zwłaszcza u chorych z obniżoną LVEF. (Folia Cardiologica Excerpta 2010; 5, 5: 266-272

    The hOGG1 Ser326Cys polymorphism and prostate cancer risk: a meta-analysis of 2584 cases and 3234 controls

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    <p>Abstract</p> <p>Background</p> <p>Genetic polymorphism of human 8-oxoguanine glycosylase 1 (hOGG1) Ser326Cys (rs1052133) has been implicated to alter the risk of prostate cancer, but the results are controversial.</p> <p>Methods</p> <p>Two investigators independently searched the Medline, and Cochrane Library up to June 7, 2011. Summary odds ratios (OR) and 95% confidence interval (CI) for Ser326Cys polymorphism and prostate cancer were calculated. Statistical analysis was performed with the software program Review Manage, version 5.0 and Stata 10.0.</p> <p>Results</p> <p>A total of 8 independent studies, including 2584 cases and 3234 controls, were identified. Our analysis suggested that Ser326Cys was not associated with prostate cancer risk in overall population. In the subgroup analysis, we detected the significant association between Ser326Cys polymorphism and decreased prostate risk in mixed population under additive model (OR = 0.67, 95% CI = 0.50-0.90, P = 0.007), recessive model (OR = 0.68, 95% CI = 0.51-0.91, P = 0.008), and Cys allele versus Ser allele (OR = 0.88, 95% CI = 0.78-0.98, P = 0.02). Subanalysis on Caucasian subjects demonstrated that Ser326Cys was not associated with prostate cancer risk.</p> <p>Conclusion</p> <p>This meta-analysis showed the evidence that hOGG1 Ser326Cys polymorphism was associated with a decreased risk of prostate cancer development in mixed populations.</p
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