A5057206109- Photoacoustic and Ultrasonic Imaging
- Optical Imaging and Spectroscopy Techniques
- Thermography and Photoacoustic Techniques
- Ultrasound Imaging and Elastography
- Ultrasonics and Acoustic Wave Propagation
- Ultrasound and Hyperthermia Applications
- Catalytic Alkyne Reactions
- Nitric Oxide and Endothelin Effects
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Synthesis and Catalytic Reactions
- Traditional and Medicinal Uses of Annonaceae
- Chemical synthesis and alkaloids
- Non-Invasive Vital Sign Monitoring
- Synthesis and Characterization of Pyrroles
- Electrical and Bioimpedance Tomography
- Synthetic Organic Chemistry Methods
- Nanoplatforms for cancer theranostics
- Porphyrin and Phthalocyanine Chemistry
- Vanadium and Halogenation Chemistry
- EEG and Brain-Computer Interfaces
- Ferroelectric and Piezoelectric Materials
- Alkaloids: synthesis and pharmacology
- Sulfur-Based Synthesis Techniques
- Heart Rate Variability and Autonomic Control
- Analytical Chemistry and Chromatography
Novartis Institutes for BioMedical Research
2022
Novartis (Switzerland)
2022
University of Alberta
1999-2017
Novartis (United States)
2017
Women and Children’s Health Research Institute
2016
University of Warwick
2010-2012
Columbia University
2011-2012
University of British Columbia
2004-2010
Simon Fraser University
2004
Florida State University
1993
Dry electrodes are becoming popular for both lab-based and consumer-level electrophysiological-recording technologies because they better afford the ability to move traditional research into real world. It is unclear, however, how dry compare in data quality electrodes. The current study compared three EEG electrode types: (a) passive-wet with no onboard amplification, (b) actively amplified, wet moderate impedance levels, low (c) active-dry very high impedance. Participants completed a...
Either silver trifluoromethanesulfonate or a mixture of gold(I) chloride, trifluoromethanesulfonate, and triphenylphosphine catalyze the formation pyrroles from substituted β-alkynyl ketones amines. The reactions proceed by using 5 mol % catalyst with yields isolated ranging 13% to 92%. Sixteen examples are used compare effectiveness each catalyst.
[reaction: see text] Cyclic ene-N-p-toluenesulfonamides tethered to an electron-deficient alkyne undergo cycloisomerizations readily under the influence of catalytic Pt(II) salts (PtCl2 or [dppbPtmu-OH]2(BF4)2) AgOTf. Yields for this process range from 47% 99%. The resulting functionalized 2-azahydrindans can be reacted further using Diels-Alder reaction. Tandem cycloisomerization-cycloaddition reactions in one pot generate highly 1-azadecalin ring systems a stereocontrolled manner.
Cyclic enesulfonamides, enecarbamates, or enamides tethered to an alkyne cyclize readily with use of platinum(II) chloride. This reaction generates quaternary-substituted carbon centers within simple spiro-fused more complex tri- and tetracyclic heterocyclic ring systems. The yields for this process range from 50% 83%. [reaction: see text].
We report on the development of an imaging system capable combined ultrasound and photoacoustic based a fast-scanning single-element 25-MHz transducer unique light-delivery system. The is 20 frames per second slower frame rates limited by laser pulse-repetition rates. Laser pulses are interlaced for co-registration images. In vivo human finger permits ultrasonic visualization vessel structures speckle changes indicative blood flow, while overlaid images highlight some small vessels that not...
A highly efficient and step-economical synthesis of zincophorin methyl ester has been achieved. The unprecedented step economy this is principally due to an application the tandem silylformylation-crotylsilylation/Tamao oxidation-diastereoselective tautomerization reaction, which achieves in a single what would typically require significant multistep sequence.
A modular and concise total synthesis of (±)-daurichromenic acid has been accomplished in four steps from ethyl acetoacetate, crotonate, trans,trans-farnesal. series analogues this natural product, which potent anti-HIV activity, were also prepared or methyl acetoacetate a readily available α,β-unsaturated esters aldehydes.
The metabolic rate of oxygen consumption, an important indicator tissue metabolism, can be expressed as the change net blood flux into and out a region per 100 g tissue. In this work, we propose photoacoustic Doppler ultrasound method for imaging local single vessel. An system combined high-frequency microscopy is presented. This uses swept-scan 25-MHz transducer with confocal dark-field laser illumination optics. A pulse-sequencer enables ultrasonic pulses to interlaced so that images are...
Despite myriad potential advantages over piezoelectric ultrasound transducers, capacitive micromachined transducers (CMUTs) have not yet seen widespread commercial implementation. The possible reasons for this may include key issues of the following: (1) long-term device reliability and (2) electrical safety associated with relatively high voltage electrodes on surfaces which could present an hazard to patients. A CMUT design presented here mitigate some these problems. Dielectric charging...
The key compound responsible for the aroma of bread, 6-acetyl-1,2,3,4-tetrahydropyridine (1), has been constructed in an efficient three-step procedure from 2-piperidone overall yield 56%. Compound 1 was liberated final step under basic conditions. A related synthetic route produced 2-acetyl-1-pyrroline (2), principal component cooked rice, 10% yield.
Cyclic enamine derivatives (enesulfonamides and enamides) tethered to an 1-arylalkynyl fragment undergo a platinum(II)-catalyzed tandem alkyne addition/Friedel-Crafts ring closure form nitrogen-containing polycyclic structures. Regioselectivity in the initial addition of enesulfonamide or enamide nucleophile platinum(II)-alkyne complex is important. Electron-rich arenes heterocycles led formation products resulting from 6-endo cyclization. Twenty-three examples this process are presented.
Photoacoustic tomography is a promising imaging modality offering high ultrasonic resolution with intrinsic optical contrast.However, quantification in photoacoustic challenging.We present an algorithm for quantitative estimation of absorption and diffusion coefficients based on minimizing error function between measured channel data calculated forward model multiple-illumination pattern.Unlike many other algorithms, the proposed method does not require erroneous assumption ideal tomographic...
Abstract A pulsed Nd : YAG laser is focused to a sharp ring on an aluminium sample in the thermoelastic regime. This achieved by firstly expanding collimated beam before passing it through bi-convex lens and axicon lens. The addition of extra convex provides significant focusing improvement. On thick samples, this shape acoustic source generates simultaneously surface Rayleigh wave bulk waves. waves generated travel outwards from also inwards focus at point centre ring. Large amplitude are...
Recently, top-orthogonal-to-bottom electrode 2-D arrays were introduced as a practical design for 3-D ultrasound imaging without requiring the wiring of grid elements. However, previously proposed schemes suffered from speed or image-quality limitations. Here, we propose new scheme which call Fast Orthogonal Row-Column Electronic Scanning (FORCES). This approach takes advantage bias sensitivity to enable high-quality and fast B-scan imaging. We compare this with an equivalent linear array,...
Depuis le début des années 1980, les greffes se sont multipliées tant en nombre qu'en variété, partout dans monde. L'augmentation s'est accompagnée de l'émergence d'un marché pour organes humains. Il est soumis présent article que, bien que humains dépende progrès technologiques, il convient considérer une perspective plus large, celle la mondialisation, soit l'extension et l'intensification du mode d'échange capitaliste. De ce point vue, avancé commerce reflète système normal d'échanges...
The optical absorption of tissues provides important information for clinical and pre-clinical studies.The challenge in recovering from photoacoustic images is that the measured pressure depends on local fluence.One reconstruction approach uses a fixed-point iterative technique based minimizing mean-squared error combined with modeling light source to determine absorption.With this technique, convergence not guaranteed even an accurate measure scattering.In work we demonstrate using...
Synthetic transmit aperture (STA) ultrasound imaging offers near-ideal reconstruction across an entire field of view. This performance comes at the cost SNR compared with scanning using only dynamic receive focusing. may be enhanced by spatial encoding a Hadamard sequence. An based on sequence has two main drawbacks: array must capable transmitting pulse and inverted same time, transmission symmetrical respect to non-inverted transmission. These are often not case in practice, thus require...
Traditional synthetic aperture ultrasound scanning involves firing on one element and receiving all elements of an array, then another transmit until transmit-receive pairs have been sampled. It offers excellent resolution but at the expense signal-to-noise. To remedy this difficulty we propose encoding scheme that multiple sampled from a Hadamard S-matrix, applying matrix inversion methods to decouple signals recover effective imaging set for subsequent image reconstruction. Because more...
Heart rate, measured in beats per minute, can be used as an index of individual's physiological state. Each time the heart beats, blood is expelled and travels through body. This flow detected face using a standard webcam that able to pick up subtle changes color cannot seen by naked eye. Due light absorption spectrum blood, we are detect differences amount absorbed traveling just below skin (i.e., photoplethysmography). By modulating emotional stress-that is, viewing arousing images sitting...