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https://www.readbyqxmd.com/read/28814850/increased-parasympathetic-cardiac-modulation-in-patients-with-acute-exacerbation-of-copd-how-should-we-interpret-it
#1
Erika Zavaglia Kabbach, Adriana Mazzuco, Audrey Borghi-Silva, Ramona Cabiddu, Aline Galvão Agnoleto, Jessica Fernanda Barbosa, Luiz Carlos Soares de Carvalho Junior, Renata Gonçalves Mendes
BACKGROUND: Cardiac autonomic modulation (CAM) is impaired in patients with stable COPD. Exacerbation aggravates the patients' health status and functional capacity. While the clinical and functional effects of exacerbation are known, no studies investigated CAM during exacerbation and whether there is a relationship between CAM and functional capacity and dyspnea. METHODS: Thirty-two patients with moderate to severe COPD were enrolled into two groups: stable COPD (GSta, n=16) and acute exacerbation of COPD (GAE, n=16)...
2017: International Journal of Chronic Obstructive Pulmonary Disease
https://www.readbyqxmd.com/read/28808439/saxs4coll-an-integrated-software-tool-for-analysing-fibrous-collagen-based-tissues
#2
Ahmed Abass, James S Bell, Martin T Spang, Sally Hayes, Keith M Meek, Craig Boote
This article provides an overview of a new integrated software tool for reduction and analysis of small-angle X-ray scattering (SAXS) data from fibrous collagen tissues, with some wider applicability to other cylindrically symmetric scattering systems. SAXS4COLL combines interactive features for data pre-processing, bespoke background subtraction, semi-automated peak detection and calibration. Both equatorial and meridional SAXS peak parameters can be measured, and the former can be deconstructed into cylinder and lattice contributions...
August 1, 2017: Journal of Applied Crystallography
https://www.readbyqxmd.com/read/28771171/vehicle-speed-and-length-estimation-using-data-from-two-anisotropic-magneto-resistive-amr-sensors
#3
Vytautas Markevicius, Dangirutis Navikas, Adam Idzkowski, Algimantas Valinevicius, Mindaugas Zilys, Darius Andriukaitis
Methods for estimating a car's length are presented in this paper, as well as the results achieved by using a self-designed system equipped with two anisotropic magneto-resistive (AMR) sensors, which were placed on a road lane. The purpose of the research was to compare the lengths of mid-size cars, i.e., family cars (hatchbacks), saloons (sedans), station wagons and SUVs. Four methods were used in the research: a simple threshold based method, a threshold method based on moving average and standard deviation, a two-extreme-peak detection method and a method based on the amplitude and time normalization using linear extrapolation (or interpolation)...
August 3, 2017: Sensors
https://www.readbyqxmd.com/read/28752757/a-detailed-investigation-and-comparison-of-the-xcms-and-mzmine-2-chromatogram-construction-and-chromatographic-peak-detection-methods-for-preprocessing-mass-spectrometry-metabolomics-data
#4
Owen D Myers, Susan J Sumner, Shuzhao Li, Stephen Barnes, Xiuxia Du
XCMS and MZmine 2 are two widely used software packages for preprocessing untargeted LC/MS metabolomics data. Both construct extracted ion chromatograms (EICs) and detect peaks from the EICs, the first two steps in the data preprocessing workflow. While both packages have performed admirably in peak picking, they also detect a problematic number of false positive EIC peaks and can also fail to detect real EIC peaks. The former and latter translate downstream into spurious and missing compounds, and present significant limitations with most existing software packages that preprocess untargeted mass spectrometry metabolomics data...
July 28, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28752754/one-step-forward-for-reducing-false-positive-and-false-negative-compound-identifications-from-mass-spectrometry-metabolomics-data-new-algorithms-for-constructing-extracted-ion-chromatograms-and-detecting-chromatographic-peaks
#5
Owen D Myers, Susan J Sumner, Shuzhao Li, Stephen Barnes, Xiuxia Du
False positive and false negative peaks detected from extracted ion chromatograms (EIC) are an urgent problem with existing software packages that preprocess untargeted liquid or gas chromatography-mass spectrometry metabolomics data because they can translate downstream into spurious or missing compound identifications. We have developed new algorithms that carry out the sequential construction of EICs and detection of EIC peaks. We compare the new algorithms to two popular software packages XCMS and MZmine 2, and present evidence that these new algorithms detect significantly fewer false positives...
July 28, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28731935/predictive-value-of-the-water-drinking-test-and-the-risk-glaucomatous-visual-field-progression
#6
Carlos G De Moraes, Remo Susanna, Lisandro M Sakata, Marcelo Hatanaka
PURPOSE: The purpose of this is to test the hypothesis the intraocular pressure (IOP) peaks during a stress test [the water drinking test (WDT)] can estimate the risk of future visual field progression in treated primary open-angle glaucoma (POAG) patients. PATIENTS AND METHODS: Design: Prospective, longitudinal study. SETTING: Clinical practice. STUDY POPULATION: Treated POAG patients whose IOP was ≤18 mm Hg and who had no IOP-lowering interventions between the date of the WDT and the last eligible visual field...
July 20, 2017: Journal of Glaucoma
https://www.readbyqxmd.com/read/28708586/whole-genome-and-transcriptome-analysis-reveal-maldi-tof-ms-and-sds-page-have-limited-performance-for-the-detection-of-the-key-outer-membrane-protein-in-carbapenem-resistant-klebsiella-pneumoniae-isolates
#7
Naina Adren Pinto, Roshan D'Souza, In Sik Hwang, Jongrak Choi, Yong Ha In, Hyung Soon Park, Choong-Min Ryu, Dongeun Yong, Kyungwon Lee
To detect the outer membrane protein (OMP), which plays a key role in carbapenem resistance, whole-genome and transcriptome analysis of the clinical carbapenem-resistant Klebsiella pneumoniae was carried out. The index strain lacked both OmpK35 and OmpK36, whereas the other strains lacked only OmpK35. After SDS-PAGE, the putative OMP bands were excised and identified as OmpA and OmpK36. MALDI-TOF MS showed peaks at ~36 and ~38 kDa that corresponded to OmpA and OmpK36, respectively. In all the strains except YMC2014/03/P345, the ~38 kDa peaks were present...
July 5, 2017: Oncotarget
https://www.readbyqxmd.com/read/28678241/enhanced-sensitivity-and-metabolite-coverage-with-remote-laser-ablation-electrospray-ionization-mass-spectrometry-aided-by-coaxial-plume-and-gas-dynamics
#8
Jarod A Fincher, Andrew R Korte, Brent Reschke, Nicholas J Morris, Matthew J Powell, Akos Vertes
Laser ablation electrospray ionization-mass spectrometry (LAESI-MS) allows for direct analysis of biological tissues at atmospheric pressure with minimal to no sample preparation. In LAESI, a mid-IR laser beam (λ = 2.94 μm) is focused onto the sample to produce an ablation plume that is intercepted and ionized by an electrospray at the inlet of the mass spectrometer. In the remote LAESI platform, the ablation process is removed from the mass spectrometer inlet and takes place in an ablation chamber, allowing for incorporation of additional optics for microscopic imaging and targeting of specific features of the sample for laser ablation sampling...
July 5, 2017: Analyst
https://www.readbyqxmd.com/read/28674558/analysis-of-stable-isotope-assisted-metabolomics-data-acquired-by-high-resolution-mass-spectrometry
#9
X Wei, P K Lorkiewicz, B Shi, J K Salabei, B G Hill, S Kim, C J McClain, X Zhang
Stable isotope assisted metabolomics (SIAM) uses stable isotope tracers to support studies of biochemical mechanisms. We report a suite of data analysis algorithms for automatic analysis of SIAM data acquired on a high resolution mass spectrometer. To increase the accuracy of isotopologue assignment, metabolites detected in the unlabeled samples were used as reference metabolites to generate possible isotopologue candidates for analysis of peaks detected in the labeled samples. An iterative linear regression model was developed to deconvolute the overlapping isotopic peaks of isotopologues present in a full MS spectrum, where the threshold for the weight factor was determined by a simulation study assuming different levels of Gaussian white noise contamination...
April 21, 2017: Analytical Methods: Advancing Methods and Applications
https://www.readbyqxmd.com/read/28668515/elucidation-of-photocatalysis-photoluminescence-and-antibacterial-studies-of-zno-thin-films-by-spin-coating-method
#10
K Kaviyarasu, C Maria Magdalane, K Kanimozhi, J Kennedy, B Siddhardha, E Subba Reddy, Naresh Kumar Rotte, Chandra Shekhar Sharma, F T Thema, Douglas Letsholathebe, Genene Tessema Mola, M Maaza
The ZnO thin films have been prepared by spin coating followed by annealing at different temperatures like 300°C, 350°C, 400°C, 450°C, 500°C & 550°C and ZnO nanoparticles have been used for photocatalytic and antibacterial applications. The morphological investigation and phase analysis of synthesized thin films well characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Photoluminescence (PL), Transmission Electron Microscopy (TEM) and Raman studies. The luminescence peaks detected in the noticeable region between 350nm to 550nm for all synthesized nanosamples are associated to the existence of defects of oxygen sites...
June 23, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28666530/development-of-a-supercritical-fluid-chromatography-method-with-ultraviolet-and-mass-spectrometry-detection-for-the-characterization-of-biomass-fast-pyrolysis-bio-oils
#11
Julien Crepier, Agnès Le Masle, Nadège Charon, Florian Albrieux, Sabine Heinisch
The characterization of complex mixtures is a challenging issue for the development of innovative processes dedicated to biofuels and bio-products production. The huge number of compounds present in biomass fast pyrolysis oils combined with the large diversity of chemical functions represent a bottleneck as regards analytical technique development. For the extensive characterization of complex samples, supercritical fluid chromatography (SFC) can be alternative to usual separation techniques such as gas (GC) or liquid chromatography (LC)...
August 11, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28644795/a-novel-short-term-event-extraction-algorithm-for-biomedical-signals
#12
Sasan Yazdani, Sibylle Fallet, Jean-Marc Vesin
In this paper we propose a fast novel non-linear filtering method named Relative-Energy (Rel-En), for robust short-term event extraction from biomedical signals. We developed an algorithm that extracts short- and long-term energies in a signal and provides a coefficient vector with which the signal is multiplied, heightening events of interest. This algorithm is thoroughly assessed on benchmark datasets in three different biomedical applications namely, ECG QRS-complex detection, EEG K-complex detection, and imaging photoplethysmography (iPPG) peak detection...
June 21, 2017: IEEE Transactions on Bio-medical Engineering
https://www.readbyqxmd.com/read/28570056/intensity-independent-noise-filtering-in-ft-ms-and-ft-ms-ms-spectra-for-shotgun-lipidomics
#13
Kai Schuhmann, Henrik Thomas, Jacobo Miranda Ackerman, Konstantin O Nagornov, Yury O Tsybin, Andrej Shevchenko
Shotgun lipidomics relies on the direct infusion of total lipid extracts into a high resolution tandem mass spectrometer. A single shotgun analysis produces several hundred of densely populated FT MS and FT MS/MS spectra, each of which might comprise thousands of peaks although a very small percentage of those belong to lipids. Eliminating noise by adjusting a minimal peak intensity threshold is biased and inefficient since lipid species and classes vary in their natural abundance and ionization capacity. We developed a method of peak intensity-independent noise filtering in shotgun FT MS and FT MS/MS spectra that capitalizes on a stable composition of the infused analyte leading to consistent time-independent detection of its bona fide components...
June 15, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/28567128/noninvasive-fetal-electrocardiography-part-i-pan-tompkins-algorithm-adaptation-to-fetal-r-peak-identification
#14
Angela Agostinelli, Ilaria Marcantoni, Elisa Moretti, Agnese Sbrollini, Sandro Fioretti, Francesco Di Nardo, Laura Burattini
BACKGROUND: Indirect fetal electrocardiography is preferable to direct fetal electrocardiography because of being noninvasive and is applicable also during the end of pregnancy, besides labor. Still, the former is strongly affected by noise so that even R-peak detection (which is essential for fetal heart-rate evaluations and subsequent processing procedures) is challenging. Some fetal studies have applied the Pan-Tompkins' algorithm that, however, was originally designed for adult applications...
2017: Open Biomedical Engineering Journal
https://www.readbyqxmd.com/read/28559848/efficient-fetal-maternal-ecg-signal-separation-from-two-channel-maternal-abdominal-ecg-via-diffusion-based-channel-selection
#15
Ruilin Li, Martin G Frasch, Hau-Tieng Wu
There is a need for affordable, widely deployable maternal-fetal ECG monitors to improve maternal and fetal health during pregnancy and delivery. Based on the diffusion-based channel selection, here we present the mathematical formalism and clinical validation of an algorithm capable of accurate separation of maternal and fetal ECG from a two channel signal acquired over maternal abdomen. The proposed algorithm is the first algorithm, to the best of the authors' knowledge, focusing on the fetal ECG analysis based on two channel maternal abdominal ECG signal, and we apply it to two publicly available databases, the PhysioNet non-invasive fECG database (adfecgdb) and the 2013 PhysioNet/Computing in Cardiology Challenge (CinC2013), to validate the algorithm...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/28504936/wave-mode-discrimination-of-coded-ultrasonic-guided-waves-using-two-dimensional-compressed-pulse-analysis
#16
Sergio Malo, Sina Fateri, Makis Livadas, Cristinel Mares, Tat-Hean Gan
Ultrasonic guided waves testing is a technique successfully used in many industrial scenarios worldwide. For many complex applications, the dispersive nature and multimode behavior of the technique still poses a challenge for correct defect detection capabilities. In order to improve the performance of the guided waves, a 2-D compressed pulse analysis is presented in this paper. This novel technique combines the use of pulse compression and dispersion compensation in order to improve the signal-to-noise ratio (SNR) and temporal-spatial resolution of the signals...
July 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
https://www.readbyqxmd.com/read/28495007/a-lightweight-qrs-detector-for-single-lead-ecg-signals-using-a-max-min-difference-algorithm
#17
Diptangshu Pandit, Li Zhang, Chengyu Liu, Samiran Chattopadhyay, Nauman Aslam, Chee Peng Lim
BACKGROUND AND OBJECTIVES: Detection of the R-peak pertaining to the QRS complex of an ECG signal plays an important role for the diagnosis of a patient's heart condition. To accurately identify the QRS locations from the acquired raw ECG signals, we need to handle a number of challenges, which include noise, baseline wander, varying peak amplitudes, and signal abnormality. This research aims to address these challenges by developing an efficient lightweight algorithm for QRS (i.e., R-peak) detection from raw ECG signals...
June 2017: Computer Methods and Programs in Biomedicine
https://www.readbyqxmd.com/read/28494427/on-line-detection-of-escherichia-coli-intrusion-in-a-pilot-scale-drinking-water-distribution-system
#18
Jenni Ikonen, Tarja Pitkänen, Pascal Kosse, Robert Ciszek, Mikko Kolehmainen, Ilkka T Miettinen
Improvements in microbial drinking water quality monitoring are needed for the better control of drinking water distribution systems and for public health protection. Conventional water quality monitoring programmes are not always able to detect a microbial contamination of drinking water. In the drinking water production chain, in addition to the vulnerability of source waters, the distribution networks are prone to contamination. In this study, a pilot-scale drinking-water distribution network with an on-line monitoring system was utilized for detecting bacterial intrusion...
May 8, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28420215/a-phonocardiographic-based-fiber-optic-sensor-and-adaptive-filtering-system-for-noninvasive-continuous-fetal-heart-rate-monitoring
#19
Radek Martinek, Jan Nedoma, Marcel Fajkus, Radana Kahankova, Jaromir Konecny, Petr Janku, Stanislav Kepak, Petr Bilik, Homer Nazeran
This paper focuses on the design, realization, and verification of a novel phonocardiographic- based fiber-optic sensor and adaptive signal processing system for noninvasive continuous fetal heart rate (fHR) monitoring. Our proposed system utilizes two Mach-Zehnder interferometeric sensors. Based on the analysis of real measurement data, we developed a simplified dynamic model for the generation and distribution of heart sounds throughout the human body. Building on this signal model, we then designed, implemented, and verified our adaptive signal processing system by implementing two stochastic gradient-based algorithms: the Least Mean Square Algorithm (LMS), and the Normalized Least Mean Square (NLMS) Algorithm...
April 18, 2017: Sensors
https://www.readbyqxmd.com/read/28388939/auto-detection-and-segmentation-of-daily-living-activities-during-a-timed-up-and-go-task-in-people-with-parkinson-s-disease-using-multiple-inertial-sensors
#20
Hung Nguyen, Karina Lebel, Patrick Boissy, Sarah Bogard, Etienne Goubault, Christian Duval
BACKGROUND: Wearable sensors have the potential to provide clinicians with access to motor performance of people with movement disorder as they undergo intervention. However, sensor data often have to be manually classified and segmented before they can be processed into clinical metrics. This process can be time consuming. We recently proposed detection and segmentation algorithms based on peak detection using Inertial Measurement Units (IMUs) to automatically identify and isolate common activities during daily living such as standing up, walking, turning, and sitting down...
April 7, 2017: Journal of Neuroengineering and Rehabilitation
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