A5054220258- Terahertz technology and applications
- Optical Imaging and Spectroscopy Techniques
- Spectroscopy and Quantum Chemical Studies
- Spectroscopy and Laser Applications
- Photoacoustic and Ultrasonic Imaging
- Quantum Dots Synthesis And Properties
- Chalcogenide Semiconductor Thin Films
- Advanced Chemical Physics Studies
- Gas Sensing Nanomaterials and Sensors
- Electromagnetic Scattering and Analysis
- Electronic and Structural Properties of Oxides
- Transition Metal Oxide Nanomaterials
- Electromagnetic Simulation and Numerical Methods
- Medical Imaging Techniques and Applications
- Advanced Fluorescence Microscopy Techniques
- Heart Failure Treatment and Management
- Semiconductor Quantum Structures and Devices
- Protein purification and stability
- Peptidase Inhibition and Analysis
- Muscle Physiology and Disorders
- Advanced Thermoelectric Materials and Devices
- Microwave Engineering and Waveguides
- Spectroscopy Techniques in Biomedical and Chemical Research
- Monoclonal and Polyclonal Antibodies Research
- Atrial Fibrillation Management and Outcomes
Novartis (United States)
2011-2024
Harvard University
2004-2007
Massachusetts General Hospital
2004-2007
Imaging Center
2004-2007
Massachusetts Institute of Technology
2005
Yale University
2000-2004
National Renewable Energy Laboratory
2003
University of Central Florida
2002
Lake Forest College
1995-1997
Columbia University
1997
Terahertz spectroscopy emerged about 13 years ago with the demonstration that nearly single-cycle pulses of far-infrared radiation could be generated, propagated through free space, and subsequently detected in time-domain. Since then, THz has found widespread applicability studies ranging from condensed matter physics to gas-phase biomedical imaging. In this article, properties applications are described context work being done Schmuttenmaer labs at Yale University. particular, it is shown...
The onset and decay of photoconductivity in bulk GaAs has been measured with 200-fs temporal resolution using time-resolved THz spectroscopy. A low carrier density $(<2\ifmmode\times\else\texttimes\fi{}{10}^{16} {\mathrm{cm}}^{\ensuremath{-}3})$ less than 100-meV kinetic energy was generated via photoexcitation. conductivity monitored a noncontact fashion through absorption (far-infrared) pulses several hundred femtosecond duration. complex-valued rises nonmonotonically, displays nearly...
It is shown that the laser induced ultrafast demagnetization of ferromagnetic films results in emission a terahertz electromagnetic pulse. This has been detected from Ni using free-space electro-optic sampling. The radiated electric field E(t) explained by Maxwell equations (radiation time dependent magnetic dipole), and expected to be proportional second derivative magnetization d2M/dt2, as measured far field. technique opens appealing perspectives context measuring understanding spin...
The transient photoconductivity of dye-sensitized titanium dioxide has been measured using time-resolved terahertz spectroscopy, a noncontact electrical probe with sub-picosecond temporal resolution. deviates strongly from Drude behavior and is explained by disorder-induced carrier localization and/or backscattering the photogenerated carriers. In addition, carriers are found to thermally equilibrate lattice in roughly 300 fs. Ramifications for understanding function DSSCs transport...
The transient photoconductivity in a 1 μm layer of low temperature grown GaAs (LT-GaAs) on substrate was measured using time-resolved terahertz spectroscopy. When photoexcitation occurs at 400 nm we find time-dependent mobility that increases from 400±100 to 1100±100 cm2 V−1 s−1 with time constant 2 ps. Photoexcitation 800 produces time-independent 3000±500 s−1. We determine the carrier lifetime LT-GaAs be 1.1 ± 0.1
Estrogen-related receptor gamma (ERRgamma) regulates the perinatal switch to oxidative metabolism in myocardium. We wanted understand significance of induction ERRgamma expression skeletal muscle by exercise. Muscle-specific VP16ERRgamma transgenic mice demonstrated an increase exercise capacity, mitochondrial enzyme activity, and enlarged mitochondria despite lower weights. Furthermore, peak capacity was higher transgenics as compared with control littermates. In contrast, lacking one copy...
The size-dependent transient photoconductivity in CdSe nanoparticles (NPs) has been investigated using time-resolved THz spectroscopy (TRTS). We find that the mobility increases with an r4 dependence for NPs strong confinement regime and is governed by a restricted mean free path weak regime. photoexcited carriers undergo ballistic transport to surface of NPs. average number electron−hole pairs generated falls into three distinct groupings based on NP radius.
We present the first, to our knowledge, experimental images of complex-shaped phantoms embedded in diffuse media by use optical tomography. Imaging is based on a complete-angle projection tomographic technique that utilizes transmitted early photons. Results are contrasted with measurements obtained at later gates as well pseudocontinuous-wave data. The scanning system developed employs noncontact illumination and detection technologies allow for high spatial sampling Combining this found be...
Fluorescence imaging of tissues has gained significant attention in recent years due to the emergence appropriate reporter technologies that enable noninvasive sensing molecular function vivo. Two major approaches have been used so far for fluorescence imaging, i.e., epi-illumination (reflectance) and tomography. Transillumination is an alternative approach employed past could be similarly beneficial imaging. We investigate data normalization schemes reflectance transillumination mode...
We report the direct measurement of intramolecular electron transfer by detecting electromagnetic (EM) waveform that is emitted during this process. It detected in time domain via free-space electro-optic sampling and then related to dynamics charge-transfer event. Electromagnetic pulse generation from two systems, Betaine-30 chloroform DMANS toluene, are studied illustrate technique. A finite-difference time-domain calculation with a time-dependent polarization used model EM propagation...
Arrays and lattices formed from nanoparticles (NPs) present unique opportunities for new optoelectronic materials whose properties can be tuned by controlling the size of individual NPs their interparticle separation to effect strong inter-NP electronic coupling. Characterization interdot coupling as a function distance is essential. Using time-resolved THz spectroscopy, we report six-fold increase in transient photoconductivity disordered arrays 3.2 nm diameter InP separated 0.9 compared...
Recent advances in optical imaging systems and systemically administered fluorescent probes have significantly improved the ways by which we can visualize proteomics vivo. A key component design of is a favorable biodistribution, i.e., localization only targeted diseased tissue, order to achieve high contrast good detection characteristics. In practice, however, there always some level background fluorescence present that could result distorted or obscured visualization quantification...
As small animal optical imaging and tomography are gaining popularity for interrogating functional molecular events in vivo, it becomes increasingly necessary to gain knowledge of the properties species investigated better understand describe photon propagation through their tissues. To achieve characterization spatial variation average murine chest cavities, time- spatially resolved measurements femto-second laser pulse transmission performed mice using a high-speed gated image intensifier....
The mouse is a useful preclinical species for evaluating disease etiology due to the availability of wide variety genetically modified strains and ability perform disease-modifying manipulations. In order establish an atrial filtration (AF) model in our laboratory, we profiled several commonly used murine AF models. We initially evaluated pharmacological acute carbachol (CCh) treatment plus burst pacing C57BL/6 mice. effort observe micro-reentrant circuits indicative authentic AF, employed...
Fluorescence molecular tomography (FMT) has emerged as a means of quantitatively imaging fluorescent probes in three dimensions living systems. To assess the accuracy FMT vivo, translucent plastic tubes containing turbid solution with known concentration Cy 5.5 dye are constructed and implanted subcutaneously nude mice, simulating presence tumor accumulating reporter. Comparisons between measurements made before after implantation demonstrate that reported for homogeneous phantoms extends to...
Type 2 diabetes (T2D) is caused by loss of pancreatic β-cell mass and failure the remaining β-cells to deliver sufficient insulin meet demand. β-Cell glucolipotoxicity (GLT), which refers combined, deleterious effects elevated glucose fatty acid levels on function survival, contributes T2D-associated failure. Drugs mechanisms that protect from GLT stress could potentially improve metabolic control in patients with T2D. In a phenotypic screen seeking low-molecular-weight compounds protected...
The serine protease factor XI (FXI) is a prominent drug target as it holds promise to deliver efficacious anticoagulation without an enhanced risk of major bleeds. Several efforts have been described targeting the active form enzyme, FXIa. Herein, we disclose our identify potent, selective, and orally bioavailable inhibitors Compound 1, identified from diverse library internal inhibitors, was originally designed complement D inhibitor exhibited submicromolar FXIa activity encouraging...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTMeasurement of Electromagnetic Radiation Emitted during Rapid Intramolecular Electron TransferMatthew C. Beard, Gordon M. Turner, and Charles A. SchmuttenmaerView Author Information Chemistry Department, Yale University 225 Prospect Street, New Haven, Connecticut 06520-8107 Cite this: J. Am. Chem. Soc. 2000, 122, 46, 11541–11542Publication Date (Web):November 4, 2000Publication History Received9 May 2000Revised29 September 2000Published...
This work presents a new application of the finite-difference time-domain (FDTD) method to generalized analysis phased array antennas. The generality FDTD brings important advantages antenna problem, allowing modeling complex conductor and dielectric geometries with relative ease. Additionally, broad-band periodic boundary condition is developed which allows problem be simplified unit cell computational domain. hybrid frequency/time-domain enables solution for arbitrary scan conditions in...
Measuring myotube thickness is a physiological and unbiased approach for screening therapeutic compounds that prevent skeletal muscle atrophy or induce hypertrophy. However, an accurate cell estimate often quite challenging because of the extreme heterogeneity cellular population therefore lack regular distribution perturbed myotubes. Here authors present novel method to evaluate changes in via measuring electrical impedance. They demonstrate both qualitative quantitative impedance as...
Terahertz spectroscopy represents a frontier in the field of biomedical imaging. It is possible to image complex objects that are opaque visible and infrared light. In this paper, we have used THz imaging reveal structure inside sunflower seed. We compare images based on time- frequency-domain representations scans, conclude for type specimen time-domain scans provide more detailed information than their counterparts.
Optical tomography using early photons can improve resolution and reduce the ill‐posed nature of inversion problem. In this work we use projection experimental data to investigate performance three commonly used numerical methods: random algebraic reconstruction technique (rART), singular value decomposition (SVD), conjugate‐gradient‐type method LSQR. Results are contrasted each other effects different photon propagation models also investigated. We find that all methods perform adequately...
Prognostic markers and biological pathways linked to detrimental clinical outcomes in heart failure with preserved ejection fraction (HFpEF) remain incompletely defined.