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optical flow

Vytas Reipa, Shannon K Hanna, Aaron Urbas, Lane Sander, John Elliott, Joseph Conny, Elijah J Petersen
As the production mass of multiwall carbon nanotubes (MWCNT) increases, the potential for human and environmental exposure to MWCNTs may also increase. We have shown that exposing an aqueous suspension of pristine MWCNTs to an intense oxidative treatment in an electrochemical reactor, equipped with an efficient hydroxyl radical generating Boron Doped Diamond (BDD) anode, leads to their almost complete mineralization. Thermal optical transmittance analysis showed a total carbon mass loss of over two orders of magnitude due to the electrochemical treatment, a result consistent with measurements of the degraded MWCNT suspensions using UV-vis absorbance...
April 26, 2018: Journal of Hazardous Materials
Mitchell B Robinson, Anna M Wisniowiecki, Ryan J Butcher, Mark A Wilson, M Nance Ericson, Gerard L Cote
Traumatic injury resulting in hemorrhage is a prevalent cause of death worldwide. The current standard of care for trauma patients is to restore hemostasis by controlling bleeding and administering intravenous volume resuscitation. Adequate resuscitation to restore tissue blood flow and oxygenation is critical within the first hours following admission to assess severity and avoid complications. However, current clinical methods for guiding resuscitation are not sensitive or specific enough to adequately understand the patient condition...
May 2018: Journal of Biomedical Optics
Marco Loffi, Petr Tousek, Tomas Budesinsky, Libor Lisa, Andrea Santangelo, Petr Widimsky, Viktor Kocka
This study assessed the Optical Coherence Tomography (OCT) impact on the coronary flow in ST-elevation myocardial infarction (STEMI) after bioresorbable scaffold implantation. Only few data about OCT use in STEMI are available and coronary flow before and after OCT is not well studied yet. 54 patients with OCT performed at the end of procedure from the Prague 19 trial were selected and coronary flow was evaluated as TIMI frame count (TFC) before and just after OCT. Significant increase in TIMI frame count after OCT [from 9...
May 18, 2018: Heart and Vessels
P Sprenger, M A Hoefer, G A El
A notion of hydrodynamic optical soliton tunneling is introduced in which a dark soliton is incident upon an evolving, broad potential barrier that arises from an appropriate variation of the input signal. The barriers considered include smooth rarefaction waves and highly oscillatory dispersive shock waves. Both the soliton and the barrier satisfy the same one-dimensional defocusing nonlinear Schrödinger (NLS) equation, which admits a convenient dispersive hydrodynamic interpretation. Under the scale separation assumption of nonlinear wave (Whitham) modulation theory, the highly nontrivial nonlinear interaction between the soliton and the evolving hydrodynamic barrier is described in terms of self-similar, simple wave solutions to an asymptotic reduction of the Whitham-NLS partial differential equations...
March 2018: Physical Review. E
C G L Tiofack, F Ii Ndzana, A Mohamadou, T C Kofane
We investigate the existence and stability of solitons in parity-time (PT)-symmetric optical media characterized by a generic complex hyperbolic refractive index distribution and fourth-order diffraction (FOD). For the linear case, we demonstrate numerically that the FOD parameter can alter the PT-breaking points. For nonlinear cases, the exact analytical expressions of the localized modes are obtained both in one- and two-dimensional nonlinear Schrödinger equations with self-focusing and self-defocusing Kerr nonlinearity...
March 2018: Physical Review. E
Gilda Cennamo, Claudia Rossi, Maria Angelica Breve, Nunzio Velotti, Antonio Farella, Raffaele Liuzzi, Giovanni Cennamo
PURPOSE: To describe the vascular changes of circumscribed choroidal hemangioma (CCH) after ruthenium-106 brachytherapy using optical coherence tomography angiography (angio-OCT). METHODS: Seven eyes of 7 patients diagnosed with symptomatic CCH who underwent ruthenium-106 plaque radiotherapy were included in the study. Patients underwent complete ophthalmic examination, bulbar echography and angio-OCT. The same protocol was applied 1 year after ruthenium-106 brachytherapy...
May 18, 2018: Eye
F Boschi, F De Sanctis, S Ugel, A E Spinelli
Cancer immunotherapy is a promising strategy based on the ability of the immune system to kill selected cells. In the development of an effective T-cell therapy the non-invasive cell tracking methods play a crucial role. Here we investigate the potentialities of T-cell marked with radionuclides in order to detect their localization with imaging techniques in small animal rodents. A protocol to label T-cells with 32 P-ATP was tested and evaluated. The homing of 32 P-ATP labeled T lymphocytes was investigated by Cerenkov luminescence imaging and radioluminescence imaging The first approach relies on the acquisition of Cerenkov photons produced by the beta particles emitted by the 32 P internalized by lymphocytes; the second one on the detection of photons coming from the conversion of radioactive energy in light done by scintillator crystals layered on the animals...
May 16, 2018: Journal of Biophotonics
Tung Nguyen Thanh Uong, Kyung-Hwa Lee, Sung-Ja Ahn, Kyung Won Kim, Jung-Joon Min, Hoon Hyun, Mee Sun Yoon
Introduction: Ex vivo -expanded natural killer (NK) cells are a potential candidate for cancer immunotherapy based on high cytotoxicity against malignant tumor cells. However, a limited understanding of the migration of activated NK cells toward solid tumors is a critical dilemma in the development of effective and adoptive NK cell-based immunotherapy. Methods: Ex vivo -expanded NK cells from healthy donors were stained with near-infrared fluorophores at different concentrations...
2018: Frontiers in Immunology
Yun Liu, Jesse Roll, Stephen Van Kooten, Xinyan Deng
The aerodynamic force on flying insects results from the vortical flow structures that vary both spatially and temporally throughout flight. Due to these complexities and the inherent difficulties in studying flying insects in a natural setting, a complete picture of the vortical flow has been difficult to obtain experimentally. In this paper, Schlieren , a widely used technique for highspeed flow visualization, was adapted to capture the vortex structures around freely flying hawkmoth ( Manduca ). Flow features such as leading-edge vortex, trailing-edge vortex, as well as the full vortex system in the wake were visualized directly...
May 2018: Biology Letters
Christiane Wittmann, Hardy Pfanz
Reassimilation of internal CO2 via corticular photosynthesis (PScort ) has an important effect on the carbon economy of trees. However, little is known about its role as a source of O2 supply to the stem parenchyma and its implications in consumption and movement of O2 within trees. PScort of young Populus nigra (black poplar) trees was investigated by combining optical micro-optode measurements with monitoring of stem chlorophyll fluorescence. During times of zero sap flow in spring, stem oxygen concentrations (cO2 ) exhibited large temporal changes...
May 16, 2018: New Phytologist
Leonard Bezinge, Richard M Maceiczyk, Ioannis Lignos, Maksym V Kovalenko, Andrew J deMello
Recent advances in the development of hybrid organic-inorganic lead halide perovskite (LHP) nanocrystals (NCs) have demonstrated their versatility and potential application as photovoltaics and light emitters through compositional tuning of optical properties. That said, due to their compositional complexity, the targeted synthesis of mixed-cation, mixed-halide LHP NCs still represents an immense challenge for traditional batch scale chemistry. To address this limitation, we herein report the integration of a high-throughput segmented-flow microfluidic reactor and self-optimizing algorithm for the synthesis of nanocrystals with defined emission properties...
May 16, 2018: ACS Applied Materials & Interfaces
Mikhail Viktorovich Pavlov, Tatyana Igorevna Kalganova, Yekaterina Sergeevna Lyubimtseva, Vladimir Ivanovich Plekhanov, German Yurievich Golubyatnikov, Olga Yevgenyevna Ilyinskaya, Anna Gennadjevna Orlova, Pavel Vladimirovich Subochev, Dmitriy Vladimirovich Safonov, Natalia Mikhailovna Shakhova, Anna Vladimirovna Maslennikova
The ability for noninvasive visualization of functional changes of a tumor's oxygenation and circulatory system offers new advantages for prognosis and monitoring of the treatment efficacy. The results of breast cancer oxygen state study under chemotherapy action obtained by diffuse optical spectroscopy (DOS) in combination with Doppler ultrasonic imaging are presented. Complex use of optical and ultrasound methods gives complementary information about the size of the tumor node, peculiarities of its vascular bed, rate of its blood flow as well as oxygenation, and provide a picture of the tumor response to treatment...
May 2018: Journal of Biomedical Optics
Taejin Park, Sun-Joo Jang, Myounghee Han, Sukyoung Ryu, Wang-Yuhl Oh
We demonstrate a novel hybrid-beam scanning-based quantitative optical coherence tomography angiography (OCTA) that provides high-speed wide dynamic range blood flow speed imaging. The hybrid-beam scanning scheme enables multiple OCTA image acquisitions with a wide range of multiple time intervals simultaneously providing wide dynamic range blood flow speed imaging independent of the blood vessel orientation, which was quantified over a speed range of 0.6∼104  mm/s through the blood flow phantom experiments...
May 15, 2018: Optics Letters
Paul T Charles, Varun Wadhwa, Amara Kouyate, Kelly J Mesa-Donado, Andre A Adams, Jeffrey R Deschamps, Anne W Kusterbeck
Design and evolution of explosives monitoring and detection platforms to address the challenges of trace level chemical identification have led investigations into the use of intricately designed microfluidic devices. Microfluidic devices are unique tools that possess distinct characteristics that, when designed properly and configured with optical and fluidic components, can produce detection platforms with unmatched performance levels. Herein, we report the design, fabrication and integration of a bifurcated high aspect ratio microfluidic device containing 128 microchannels (40 mm × 40 μm × 250 μm; L × W × H) for explosives detection at trace levels...
May 15, 2018: Sensors
Kun Wu, Yuanlai Peng, Guangji Sheng, Ang Li, Xiao Liu, Xiaoyan Deng, Yubo Fan
We aimed to establish an optical coherence tomography (OCT) system to measure the strain of blood vessels. A general OCT system was constructed firstly and its reliability was confirmed by comparing the OCT imaging of the porcine coronary and the corresponding histological slices. The strain of the porcine coronary was induced by static flow pressure and correlation algorithm was used to calculate the strain field of blood vessels within OCT images. The results suggest that bright-dark stratification of blood vessels displayed in OCT images is consistent with the intima and media layers of histological image...
October 1, 2017: Sheng Wu Yi Xue Gong Cheng Xue za Zhi, Journal of Biomedical Engineering, Shengwu Yixue Gongchengxue Zazhi
Vytautas Zickus, Jonathan M Taylor
We present SPIM-μPIV as a flow imaging system, capable of measuring in vivo flow information with 3D micron-scale resolution. Our system was validated using a phantom experiment consisting of a flow of beads in a 50 μm diameter FEP tube. Then, with the help of optical gating techniques, we obtained 3D + time flow fields throughout the full heartbeat in a ∼3 day old zebrafish larva using fluorescent red blood cells as tracer particles. From this we were able to recover 3D flow fields at 31 separate phases in the heartbeat...
May 1, 2018: Biomedical Optics Express
Neda Haj-Hosseini, Johan C O Richter, Peter Milos, Martin Hallbeck, Karin Wårdell
A fiber optic probe was developed for guidance during stereotactic brain biopsy procedures to target tumor tissue and reduce the risk of hemorrhage. The probe was connected to a setup for the measurement of 5-aminolevulinic acid (5-ALA) induced fluorescence and microvascular blood flow. Along three stereotactic trajectories, fluorescence (n = 109) and laser Doppler flowmetry (LDF) (n = 144) measurements were done in millimeter increments. The recorded signals were compared to histopathology and radiology images...
May 1, 2018: Biomedical Optics Express
Shaohua Pi, Acner Camino, William Cepurna, Xiang Wei, Miao Zhang, David Huang, John Morrison, Yali Jia
Accurate, quantitative assessment of retinal blood oxygen saturation ( sO2 ) may provide a useful early indicator of pathophysiology in several ocular diseases. Here, with visible-light optical coherence tomography (OCT), we demonstrate an automated spectroscopic retinal oximetry algorithm to measure the sO2 within the retinal arteries (A- sO2 ) and veins (V- sO2 ) in rats by automatically detecting the vascular posterior boundary on cross-sectional structural OCT. The algorithm was validated in vitro with flow phantoms and in vivo in rats by comparing the sO2 results, respectively, to those obtained using a blood gas analyzer and pulse oximetry...
May 1, 2018: Biomedical Optics Express
Francisco M Hernández-Maya, María P Cañizares-Macías
β-glucosidase from almonds was immobilized on a polydimethylsiloxane (PDMS) microdevice by covalent chain using 3-aminopropyltrietoxysilane and glutaraldehyde. Enzymatic activity was evaluated using p-nitro-phenyl-β-D-glucopyranoside dissolved in a 0.01 M pH 5.0 phosphate solution at 45 °C measuring the reaction product (p-nitrophenol) at 410 nm. The microdevice consisted of two parts: the one part where the enzymatic reaction was carried out and a second part where pH was adjusted at 10, with NaOH...
August 1, 2018: Talanta
Jayabrata Dhar, Suman Chakraborty
The flow of nematic liquid crystals (NLCs) in the presence of an electric field is typically characterized by the variation in its rheological properties due to transition in its molecular arrangements. Here, we bring out a nontrivial interplay of a consequent alteration in the resistive viscous effects and driving electrocapillary interactions, toward maneuvering the capillary filling dynamics over miniaturized scales. Considering a dynamic interplay of the relevant bulk and interfacial forces acting in tandem, our results converge nicely to previously reported experimental data...
April 2018: Physical Review. E
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