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https://www.readbyqxmd.com/read/28437995/single-measurement-digital-optical-frequency-comb-based-phase-detection-brillouin-optical-time-domain-analyzer
#1
Chao Jin, Liang Wang, Yuli Chen, Nan Guo, Wenghong Chung, Hoyin Au, Zhaohui Li, Hwa-Yaw Tam, Chao Lu
A single-measurement sweep-free distributed Brillouin optical time domain analyzer (BOTDA) sensor based on phase detection is proposed and experimentally demonstrated employing digital optical frequency comb (DOFC) probe signal. Brillouin Phase Spectrum (BPS) of DOFC probe induced by Brillouin interaction is measured using coherent detection in a single acquisition, without any frequency scanning and data averaging. Single-measurement BOTDA sensor based on BPS in 10km long fiber is demonstrated with a response time of 100 μs, which is limited only by the fiber length...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437994/high-speed-asynchronous-optical-sampling-based-on-ghz-yb-kyw-oscillators
#2
C Li, N Krauß, G Schäfer, L Ebner, O Kliebisch, J Schmidt, S Winnerl, M Hettich, T Dekorsy
A low-cost scheme of high-speed asynchronous optical sampling based on Yb:KYW oscillators is reported. Two GHz diode-pumped oscillators with a slight pulse repetition rate offset serve as pump and probe source, respectively. The temporal resolution of this system is limited to 500 fs mainly by the pulse duration of the oscillators and also by relative timing jitter between the oscillators. A near-shot-noise noise floor around 10<sup>-6</sup> (∆R/R) is obtained within a data acquisition time of a few seconds...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437992/a-large-airborne-survey-of-earth-s-visible-infrared-spectral-dimensionality
#3
David R Thompson, Joseph W Boardman, Michael L Eastwood, Robert O Green
The intrinsic spectral dimensionality indicates the observable degrees of freedom in Earth's solar-reflected light field, quantifying the diversity of spectral content accessible by visible and infrared remote sensing. The solar-reflected regime spans the 0.38 - 2.5 μm interval, and is captured by a wide range of current and planned instruments on both airborne and orbital platforms. To date there has been no systematic study of its spectral dimensionality as a function of space, time, and land cover. Here we report a multi-site, multi-year statistical survey by NASA's "Classic" Airborne Visible Near InfraRed Spectrometer (AVIRIS-C)...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437956/single-shot-areal-profilometry-using-hyperspectral-interferometry-with-a-microlens-array
#4
Pablo D Ruiz, Jonathan M Huntley
We describe a single-shot technique to measure areal profiles on optically smooth and stepped surfaces for applications where rapid data acquisition in non-cooperative environments is essential. It is based on hyperspectral interferometry (HSI), a technique in which the output of a white-light interferometer provides the input to a hyperspectral imaging system. Previous HSI implementations suffered from inefficient utilisation of the available pixels which limited the number of measured coordinates and/or unambiguous depth range...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437905/amplitude-modulation-of-femtosecond-laser-pulses-in-the-megahertz-range-for-frequency-multiplexed-two-photon-imaging
#5
Dmitri Tsyboulski, Natalia Orlova, Peter Saggau
We present a frequency-multiplexed multi-site two-photon imaging method utilizing amplitude modulation of femtosecond laser pulses in the MHz range to tag each excitation beam and the corresponding fluorescence signals with specific frequencies. The frequency tags are generated with an interferometric scheme employing acousto-optic deflectors (AODs) to achieve precise spatial overlap of femtosecond laser pulses with periodically varying phase shift. Creating matching excitation beam patterns in each interferometer arm using multiple AOD driving frequencies, and subsequently overlapping these matching patterns, results in multiple encoded excitation beams with unique beat frequencies available for scanning...
April 17, 2017: Optics Express
https://www.readbyqxmd.com/read/28437244/second-transcatheter-closure-for-residual-shunt-following-percutaneous-closure-of-patent-foramen-ovale
#6
Njomeza Susuri, Slayman Obeid, Mirjam Ulmi, George Cm Siontis, Andreas Wahl, Stephan Windecker, Fabian Nietlispach, Bernhard Meier, Fabien Praz
AIMS: Residual shunt following percutaneous patent foramen ovale (PFO) closure has been described in up to 49% of the patients and is associated with recurrent cerebrovascular events. Our aim was to evaluate the safety, feasibility, and mid-term outcomes of transcatheter residual shunt closure. METHODS AND RESULTS: From 1994 to July 2016, 2679 patients underwent transcatheter PFO closure for treatment of presumed paradoxical embolism at our institution. Among them, 100 patients (3...
April 25, 2017: EuroIntervention
https://www.readbyqxmd.com/read/28437229/quinolone-resistance-determinants-of-clinical-salmonella-enteritidis-in-thailand
#7
Fuangfa Utrarachkij, Chie Nakajima, Ruchirada Changkwanyeun, Kanokrat Siripanichgon, Siriporn Kongsoi, Srirat Pornruangwong, Kanjana Changkaew, Risa Tsunoda, Yutaka Tamura, Orasa Suthienkul, Yasuhiko Suzuki
Salmonella Enteritidis has emerged as a global concern regarding quinolone resistance and invasive potential. Although quinolone-resistant S. Enteritidis has been observed with high frequency in Thailand, information on the mechanism of resistance acquisition is limited. To elucidate the mechanism, a total of 158 clinical isolates of nalidixic acid (NAL)-resistant S. Enteritidis were collected throughout Thailand, and the quinolone resistance determinants were investigated in the context of resistance levels to NAL, norfloxacin (NOR), and ciprofloxacin (CIP)...
February 23, 2017: Microbial Drug Resistance: MDR: Mechanisms, Epidemiology, and Disease
https://www.readbyqxmd.com/read/28437215/contraceptive-use-and-pregnancy-incidence-among-women-participating-in-an-hiv-prevention-trial
#8
Carolyne A Akello, Katherine E Bunge, Clemensia Nakabiito, Brenda G Mirembe, Mary Glenn Fowler, Anupam Mishra, Jeanne Marrazzo, Zvavahera M Chirenje, Connie Celum, Jennifer E Balkus
BACKGROUND: Recent HIV prevention trials required use of effective contraceptive methods to fulfill eligibility for enrollment. We compared pregnancy rates in a subset of participants enrolled in the Microbicide Trials Network protocol (MTN-003), a randomized trial of chemoprophylaxis to prevent HIV acquisition among women aged 18-45 years who initiated depot medroxyprogesterone acetate (DMPA) or combined oral contraceptives (COCs) at enrollment, relative to those already using DMPA or COCs...
February 17, 2017: Journal of Women's Health
https://www.readbyqxmd.com/read/28437154/prediction-of-relapse-from-hyperthyroidism-following-antithyroid-medication-withdrawal-using-technetium-thyroid-uptake-scanning
#9
Manouchehr Nakhjavani, Soraya Abdollahi, Saeed Farzanefar, Mohammadtagi Abousaidi, Alireza Esteghamati, Maryam Naseri, Mohamad Eftekhari, Mehrshad Abbasi
OBJECTIVE: Technetium thyroid uptake (TTU) is not inhibited by antithyroid drugs (ATD) and reflects the degree of thyroid stimulation. We intended to predict the relapse rate from hyperthyroidism based on TTU measurement. METHODS: Out of 44 initially enrolled subjects, 38 patients aged 41.6 ± 14.6 with Graves disease (duration: 84 ± 78 months) completed the study. TTU was performed with 40-second imaging of the neck and mediastinum 20 minutes after injection of 1 mCi technetium-99m pertechnetate...
April 2, 2017: Endocrine Practice
https://www.readbyqxmd.com/read/28437011/noise-reduction-and-functional-maps-image-quality-improvement-in-dynamic-ct-perfusion-using-a-new-k-means-clustering-guided-bilateral-filter-kmgb
#10
Francesco Pisana, Thomas Henzler, Stefan Schönberg, Ernst Klotz, Bernhard Schmidt, Marc Kachelrieß
PURPOSE: Dynamic CT perfusion (CTP) consists in repeated acquisitions of the same volume in different time steps, slightly before, during and slightly afterwards the injection of contrast media. Important functional information can be derived for each voxel, which reflect the local hemodynamic properties and hence the metabolism of the tissue. Different approaches are being investigated to exploit data redundancy and prior knowledge for noise reduction of such datasets, ranging from iterative reconstruction schemes to high dimensional filters...
April 24, 2017: Medical Physics
https://www.readbyqxmd.com/read/28436918/an-integrated-and-highly-sensitive-ultrafast-acoustoelectric-imaging-system-for-biomedical-applications
#11
Beatrice Berthon, Pierre-Marc Dansette, Mickael Tanter, Mathieu Pernot, Jean Provost
PURPOSE: Direct imaging of cardiac electrical activation is crucial to better understand and diagnose diseases linked to arrhythmias. This work presents an Ultrafast Acoustoelectric Imaging (UAI) system for direct and non-invasive ultrafast mapping of propagating current densities. MATERIALS AND METHODS: Acoustoelectric imaging is based on the acoustoelectric effect, the modulation of the medium's electrical impedance by a propagating ultrasonic wave. UAI triggers this effect with plane wave emissions to image current densities...
April 24, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28436863/optimization-of-camera-arrangement-using-correspondence-field-to-improve-depth-estimation
#12
Shichao Fu, Farzad Safaei, Wanqing Li
Stereo matching algorithms attempt to estimate depth from the images obtained by two cameras. In most cases, the arrangement of cameras (their locations and orientations with respect to the scene) are determined based on human experience. In this paper, it is shown that the camera arrangement can be optimized using the concept of correspondence field (CF) for better acquisition of depth. Specifically, the paper demonstrates the relationship between the correspondence field of a pair of cameras and depth estimation accuracy and presents a method to optimize their arrangement based on the gradient of CF...
April 18, 2017: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
https://www.readbyqxmd.com/read/28436853/automatic-skin-lesion-segmentation-using-deep-fully-convolutional-networks-with-jaccard-distance
#13
Yading Yuan, Ming Chao, Yeh-Chi Lo
Automatic skin lesion segmentation in dermoscopic images is a challenging task due to the low contrast between lesion and the surrounding skin, the irregular and fuzzy lesion borders, the existence of various artifacts, and various imaging acquisition conditions. In this article, we present a fully automatic method for skin lesion segmentation by leveraging a 19-layer deep convolutional neural networks (CNNs) that is trained end-to- end and does not rely on prior knowledge of the data. We propose a set of strategies to ensure effective and efficient learning with limited training data...
April 18, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28436852/frequency-selective-computed-tomography-applications-during-periodic-thoracic-motion
#14
Jacob Herrmann, Eric A Hoffman, David W Kaczka
We seek to use computed tomography (CT) to characterize regional lung parenchymal deformation during highfrequency and multi-frequency oscillatory ventilation. Periodic motion of thoracic structures results in artifacts of CT images obtained by standard reconstruction algorithms, especially for frequencies exceeding that of the X-ray source rotation. In this study, we propose an acquisition and reconstruction technique for high resolution imaging of the thorax during periodic motion. Our technique relies on phase-binning projections according to the frequency of subject motion relative to the scanner rotation, prior to volumetric reconstruction...
April 18, 2017: IEEE Transactions on Medical Imaging
https://www.readbyqxmd.com/read/28436834/active-auditory-experience-in-infancy-promotes-brain-plasticity-in-theta-and-gamma-oscillations
#15
Gabriella Musacchia, Silvia Ortiz-Mantilla, Naseem Choudhury, Teresa Realpe-Bonilla, Cynthia Roesler, April A Benasich
Language acquisition in infants is driven by on-going neural plasticity that is acutely sensitive to environmental acoustic cues. Recent studies showed that attention-based experience with non-linguistic, temporally-modulated auditory stimuli sharpens cortical responses. A previous ERP study from this laboratory showed that interactive auditory experience via behavior-based feedback (AEx), over a 6-week period from 4- to 7-months-of-age, confers a processing advantage, compared to passive auditory exposure (PEx) or maturation alone (Naïve Control, NC)...
April 15, 2017: Developmental Cognitive Neuroscience
https://www.readbyqxmd.com/read/28436819/insight-into-the-evolution-of-microbial-metabolism-from-the-deep-branching-bacterium-thermovibrio-ammonificans
#16
Donato Giovannelli, Stefan M Sievert, Michael Hügler, Stephanie Markert, Dörte Becher, Thomas Schweder, Costantino Vetriani
Anaerobic thermophiles inhabit relic environments that resemble the early Earth. However, the lineage of these modern organisms co-evolved with our planet. Hence, these organisms carry both ancestral and acquired genes and serve as models to reconstruct early metabolism. Based on comparative genomic and proteomic analyses, we identified two distinct groups of genes in Thermovibrio ammonificans: the first codes for enzymes that do not require oxygen and use substrates of geothermal origin; the second appears to be a more recent acquisition, and may reflect adaptations to cope with the rise of oxygen on Earth...
April 24, 2017: ELife
https://www.readbyqxmd.com/read/28436625/-effects-of-crocin-on-hippocampus-rapid-kindling-epilepsy-in-mice
#17
Xiting Wang, Oufeng Tang, Yilu Ye, Mingzhi Zheng, Jue Hu, Zhong Chen, Kai Zhong
Objective: To investigate the effect of crocin on the progression and generalized seizure of temporal lobe epilepsy in mice. Methods: Hippocampus rapid kindling model was established in C57BL/6J mice. The effects of crocin on seizure stage, afterdischarge duration (ADD), number of stimulation in each stage and final state, the incidence of generalized seizure (GS), average seizure stage and ADD were observed. Results: Crocin (20 mg/kg) significantly retarded behavioral seizure stages ( P<0.05) and shortened cumulative ADD ( P<0...
January 25, 2017: Zhejiang da Xue Xue Bao. Yi Xue Ban, Journal of Zhejiang University. Medical Sciences
https://www.readbyqxmd.com/read/28436624/-mechanisms-of-histamine-ameliorating-memory-impairment-induced-by-pentylenetetrazole-kindling-epilepsy-in-rats
#18
Lisan Zhang, Guanfeng Chen, Jiefang Chen, Xudong He, Xingyue Hu
Objective: To investigate the effects of neuronal histamine on spatial memory acquisition impairment in rats with pentylenetetrazole-kindling epilepsy, and to explore its mechanisms. Methods: A subconvulsive dose of pentylenetetrazole (35 mg/kg) was intraperitoneally injected in rats every 48 h to induce chemical kindling until fully kindled. Morris water maze was used to measure the spatial memory acquisition of the rats one week after fully pentylenetetrazole-kindled, and the histamine contents in different brain areas were measured spectrofluorometrically...
January 25, 2017: Zhejiang da Xue Xue Bao. Yi Xue Ban, Journal of Zhejiang University. Medical Sciences
https://www.readbyqxmd.com/read/28436590/identification-of-small-molecules-using-accurate-mass-ms-ms-search
#19
REVIEW
Tobias Kind, Hiroshi Tsugawa, Tomas Cajka, Yan Ma, Zijuan Lai, Sajjan S Mehta, Gert Wohlgemuth, Dinesh Kumar Barupal, Megan R Showalter, Masanori Arita, Oliver Fiehn
Tandem mass spectral library search (MS/MS) is the fastest way to correctly annotate MS/MS spectra from screening small molecules in fields such as environmental analysis, drug screening, lipid analysis, and metabolomics. The confidence in MS/MS-based annotation of chemical structures is impacted by instrumental settings and requirements, data acquisition modes including data-dependent and data-independent methods, library scoring algorithms, as well as post-curation steps. We critically discuss parameters that influence search results, such as mass accuracy, precursor ion isolation width, intensity thresholds, centroiding algorithms, and acquisition speed...
April 24, 2017: Mass Spectrometry Reviews
https://www.readbyqxmd.com/read/28436568/effects-of-programmed-teaching-errors-on-acquisition-and-durability-of-self-care-skills
#20
Maeve G Donnelly, Amanda M Karsten
This investigation sheds light on necessary and sufficient conditions to establish self-care behavior chains among people with developmental disabilities. First, a descriptive assessment (DA) identified the types of teaching errors that occurred during self-care instruction. Second, the relative effects of three teaching errors observed during the DA were evaluated across two behavior chains for three participants. Third, the effects of individual teaching errors were studied with a third behavior chain per participant...
April 24, 2017: Journal of Applied Behavior Analysis
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