Read by QxMD icon Read

Depth sensor

Wenting Dang, Libu Manjakkal, William Taube Navaraj, Leandro Lorenzelli, Vincenzo Vinciguerra, Ravinder Dahiya
Sensor-laden wearable systems that are capable of providing continuous measurement of key physiological parameters coupled with data storage, drug delivery and feedback therapy have attracted huge interest. Here we report a stretchable wireless system for sweat pH monitoring, which is able to withstand up to 53% uniaxial strain and more than 500 cycles to 30% strain. The stretchability of the pH sensor patch is provided by a pair of serpentine-shaped stretchable interconnects. The pH sensing electrode is made of graphite-polyurethane composite, which is suitable for biosensor application...
February 10, 2018: Biosensors & Bioelectronics
Syaiful Redzwan Mohd Shah, Jacob Velander, Parul Mathur, Mauricio D Perez, Noor Badariah Asan, Dhanesh G Kurup, Taco J Blokhuis, Robin Augustine
In recent research, microwave sensors have been used to follow up the recovery of lower extremity trauma patients. This is done mainly by monitoring the changes of dielectric properties of lower limb tissues such as skin, fat, muscle, and bone. As part of the characterization of the microwave sensor, it is crucial to assess the signal penetration in in vivo tissues. This work presents a new approach for investigating the penetration depth of planar microwave sensors based on the Split-Ring Resonator in the in vivo context of the femoral area...
February 21, 2018: Sensors
Carl J Houtman, Eranda Maligaspe, Christopher G Hunt, Elena Fernandez-Fueyo, Angel T Martínez, Kenneth E Hammel
Peroxidases are considered essential agents of lignin degradation by white-rot basidiomycetes. However, low-molecular-weight oxidants likely have a primary role in lignin breakdown because many of these fungi delignify wood before its porosity has sufficiently increased for enzymes to infiltrate. It has been proposed that lignin peroxidases (LiPs, EC fulfill this role by oxidizing the secreted fungal metabolite veratryl alcohol (VA) to its aryl cation radical (VA+• ), releasing it to act as a one-electron lignin oxidant within woody plant cell walls...
February 9, 2018: Journal of Biological Chemistry
Zhenyu Liu, Rui Li, Jianrong Tan
With the introduction of cost-effective depth sensors, a tremendous amount of research has been devoted to studying human action recognition using 3D motion data. However, most existing methods work in an offline fashion, i.e., they operate on a segmented sequence. There are a few methods specifically designed for online action recognition, which continually predicts action labels as a stream sequence proceeds. In view of this fact, we propose a question: can we draw inspirations and borrow techniques or descriptors from existing offline methods, and then apply these to online action recognition? Note that extending offline techniques or descriptors to online applications is not straightforward, since at least two problems-including real-time performance and sequence segmentation-are usually not considered in offline action recognition...
February 20, 2018: Sensors
Stijn Bruneel, Sacha Gobeyn, Pieterjan Verhelst, Jan Reubens, Tom Moens, Peter Goethals
Movement is considered an essential process in shaping the distributions of species. Nevertheless, most species distribution models (SDMs) still focus solely on environment-species relationships to predict the occurrence of species. Furthermore, the currently used indirect estimates of movement allow to assess habitat accessibility, but do not provide an accurate description of movement. Better proxies of movement are needed to assess the dispersal potential of individual species and to gain a more practical insight in the interconnectivity of communities...
February 15, 2018: Science of the Total Environment
Eliza S Deutsch, Ibrahim Alameddine, Mutasem El-Fadel
The launch of the Landsat 8 in February 2013 extended the life of the Landsat program to over 40 years, increasing the value of using Landsat to monitor long-term changes in the water quality of small lakes and reservoirs, particularly in poorly monitored freshwater systems. Landsat-based water quality hindcasting often incorporate several Landsat sensors in an effort to increase the temporal range of observations; yet the transferability of water quality algorithms across sensors remains poorly examined. In this study, several empirical algorithms were developed to quantify chlorophyll-a, total suspended matter (TSM), and Secchi disk depth (SDD) from surface reflectance measured by Landsat 7 ETM+ and Landsat 8 OLI sensors...
February 15, 2018: Environmental Monitoring and Assessment
Jean Cacheux, Marie Brut, Aurélien Bancaud, Pierre Cordelier, Thierry Leichlé
In this work, we demonstrate that the analysis of spatially resolved nanofluidic-embedded biosensors permits the fast and direct discrimination of SND (single-nucleotide difference) within oligonucleotide sequences in a single step interaction. We design a sensor with a linear dimension much larger than the channel depth in order to ensure that the reaction over the whole sensor is limited by the convection rate. Thus, the targets are fully collected, inducing a non-uniform spatial hybridization profile. We also use the nanoscale height of the channel, which enables us to minimize the amount of labeled molecules flowing over the sensor and hence to reduce the fluorescence background, to carry out real-time hybridization detection by fluorescence microscopy...
February 13, 2018: ACS Sensors
Yan Liu, Renbin Zhong, Zhen Lian, Chen Bu, Shenggang Liu
Dynamically tunable band stop filter based on metal-graphene metamaterials is proposed and numerically investigated at mid-infrared frequencies. The proposed filter is constructed by unit cells with simple gold strips on the stack of monolayer graphene and the substrate of BaF2. A stable modulation depth up to -23.26 dB can be achieved. Due to the cooperative effect of the "bright-bright" elements, the amount of the gold strips in each unit cell determines the number of the stop-bands, providing a simple and flexible approach to develop multispectral devices...
February 12, 2018: Scientific Reports
M Shahzeb Khan Gul, Bahadir K Gunturk
Light field imaging extends the traditional photography by capturing both spatial and angular distribution of light, which enables new capabilities, including post-capture refocusing, post-capture aperture control, and depth estimation from a single shot. Micro-lens array (MLA) based light field cameras offer a cost-effective approach to capture light field. A major drawback of MLA based light field cameras is low spatial resolution, which is due to the fact that a single image sensor is shared to capture both spatial and angular information...
May 2018: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Xin Zhang, Fei Zeng, Yi Li, Yanfeng Qiao
High focusing accuracy in microscopes could improve the imaging quality to reduce the error rate in DNA sequencing. We propose a new feedback method to improve the focusing condition to a very high accuracy. A reference laser reflected by the sample is detected by two or more sensors around the confocal point. After acquiring the signals from the out-of-focus positions, online data processing is implemented to provide feedbacks for real-time focus-plane locking on the sample surface. This method provides an accuracy better than 1/10 of the objective depth-of-focus...
January 22, 2018: Optics Express
Yonas Muanenda, Stefano Faralli, Claudio J Oton, Fabrizio Di Pasquale
We propose and experimentally demonstrate a stable homodyne phase demodulation technique in a ϕ-OTDR using a double-pulse probe and a simple direct detection receiver. The technique uses selective phase modulation of one of a pair of pulses to generate a carrier for dynamic phase changes and involves an enhanced phase demodulation scheme suitable for distributed sensing by being robust against light intensity fluctuations, independent of the modulation depth, and convenient for analogue signal processing. The capability of the technique to quantify distributed dynamic phase change due to a generic external impact is experimentally demonstrated by measuring the phase change induced by a nonlinear actuator generating a 2 kHz perturbation at a distance of 1...
January 22, 2018: Optics Express
Elise Munz Hall, Timothy W Fahringer, Daniel R Guildenbecher, Brian S Thurow
The volumetric calibration of a plenoptic camera is explored to correct for inaccuracies due to real-world lens distortions and thin-lens assumptions in current processing methods. Two methods of volumetric calibration based on a polynomial mapping function that does not require knowledge of specific lens parameters are presented and compared to a calibration based on thin-lens assumptions. The first method, volumetric dewarping, is executed by creation of a volumetric representation of a scene using the thin-lens assumptions, which is then corrected in post-processing using a polynomial mapping function...
February 1, 2018: Applied Optics
Micheál D Scanlon, Evgeny Smirnov, T Jane Stockmann, Pekka Peljo
The functionality of liquid-liquid interfaces formed between two immiscible electrolyte solutions (ITIES) can be markedly enhanced by modification with supramolecular assemblies or solid nanomaterials. The focus of this Review is recent progress involving ITIES modified with floating assemblies of gold nanoparticles or "nanofilms". Experimental methods to controllably modify liquid-liquid interfaces with gold nanofilms are detailed. Also, we outline an array of techniques to characterize these gold nanofilms in terms of their physiochemical properties (such as reflectivity, conductivity, catalytic activity, or plasmonic properties) and physical interfacial properties (for example, interparticle spacing and immersion depth at the interface)...
January 30, 2018: Chemical Reviews
Patricia Maria Graf, Rory Paul Wilson, Lea Cohen Sanchez, Klaus Hacklӓnder, Frank Rosell
Semi-aquatic mammals have secondarily returned to the aquatic environment, although they spend a major part of their life operating in air. Moving both on land, as well as in, and under water is challenging because such species are considered to be imperfectly adapted to both environments. We deployed accelerometers combined with a depth sensor to study the diving behavior of 12 free-living Eurasian beavers Castor fiber in southeast Norway between 2009 and 2011 to examine the extent to which beavers conformed with mass-dependent dive capacities, expecting them to be poorer than wholly aquatic species...
January 2018: Ecology and Evolution
Crystal E Owens, A John Hart
Wider use and adaptation of microfluidics is hindered by the infrastructure, knowledge, and time required to build prototype systems, especially when multiple fluid operations and measurements are required. As a result, 3D printing of microfluidics is attracting interest, yet cannot readily achieve the feature size, smoothness, and optical transparency needed for many standard microfluidic systems. Herein we present a new approach to the design and construction of high-precision modular microfluidics, using standard injection-molded blocks that are modified using micromilling and assembled via elastically averaged contacts...
January 26, 2018: Lab on a Chip
Istvan Gyongy, Neale A W Dutton, Robert K Henderson
Quanta Imager Sensors provide photon detections at high frame rates, with negligible read-out noise, making them ideal for high-speed optical tracking. At the basic level of bit-planes or binary maps of photon detections, objects may present limited detail. However, through motion estimation and spatial reassignment of photon detections, the objects can be reconstructed with minimal motion artefacts. We here present the first demonstration of high-speed two-dimensional (2D) tracking and reconstruction of rigid, planar objects with a Quanta Image Sensor, including a demonstration of depth-resolved tracking...
January 23, 2018: Sensors
Shanshan Liu, Huanxiang Yuan, Haotian Bai, Pengbo Zhang, Fengting Lv, Libing Liu, Zhihui Dai, Jianchun Bao, Shu Wang
The employment of physical light source in clinical photodynamic therapy (PDT) system endow it with crucial defect in the treatment of deeper tissue lesions due to the limited penetration depth of light in biological tissues. In this work, we constructed for the first time an electric driven luminous system based on electrochemiluminescence (ECL) for killing pathogenic bacteria, where ECL is used for the excitation of photosensitizer instead of physical light source to produce reactive oxygen species (ROS)...
January 21, 2018: Journal of the American Chemical Society
Ruopeng Sun, Jacob J Sosnoff
BACKGROUND: Falls are a major health problem for older adults with significant physical and psychological consequences. A first step of successful fall prevention is to identify those at risk of falling. Recent advancement in sensing technology offers the possibility of objective, low-cost and easy-to-implement fall risk assessment. The objective of this systematic review is to assess the current state of sensing technology on providing objective fall risk assessment in older adults. METHODS: A systematic review was conducted in accordance to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement (PRISMA)...
January 16, 2018: BMC Geriatrics
Jean-Michel Friedt, Gilles Martin, Gwenhael Goavec-Mérou, David Rabus, Sébastien Alzuaga, Lilia Arapan, Marianne Sagnard, Émile Carry
Passive wireless transducers are used as sensors, probed by a RADAR system. A simple way to separate the returning signal from the clutter is to delay the response, so that the clutter decays before the echoes are received. This can be achieved by introducing a fixed delay in the sensor design. Acoustic wave transducers are ideally suited as cooperative targets for passive, wireless sensing. The incoming electromagnetic pulse is converted into an acoustic wave, propagated on the sensor substrate surface, and reflected as an electromagnetic echo...
January 16, 2018: Sensors
Minyu Xiao, Joshua Jasensky, Leanna L Foster, Kenichi Kuroda, Zhan Chen
Antimicrobial peptides (AMPs) free in solution can kill bacteria by disrupting bacterial cell membranes. Their modes of action have been extensively studied and various models ranging from Pore formation to Carpet-like mechanism were proposed. Surface immobilized AMPs have been used as coatings to kill bacteria and as sensors to capture bacteria, but the interaction mechanisms of surface immobilized AMPs and bacteria are not fully understood. In this research, an analytical platform, SFG-microscope, which is composed of a sum frequency generation (SFG) vibrational spectrometer and a fluorescence microscope, was used to probe molecular interactions between surface immobilized AMPs and bacteria in situ in real time at the solid/liquid interface...
January 15, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"