Biomarkers are indicators of biological processes and hold promise for the diagnosis treatment disease. Gliomas represent a heterogeneous group brain tumors with marked intra- inter-tumor variability. The extent surgical resection is significant factor influencing post-surgical recurrence prognosis. Here, we used fluorescence reflectance spectral signatures in vivo quantification multiple biomarkers during glioma surgery, contrast provided by exogenously-induced protoporphyrin IX (PpIX)...

Abstract Design strategies for improving terahertz (THz) quantum cascade lasers (QCLs) in the 5–6 THz range are investigated numerically and experimentally, with goal of overcoming degradation performance that occurs as laser frequency approaches Reststrahlen band. Two designs aimed at 5.4 were selected: one optimized lower power dissipation better temperature performance. The active regions exhibited broadband gain, strongest modes lasing 5.3–5.6 range, but other various observed ranging...

A. Kim, P. Bruinsma, Y. Chen, L. Wang and J. Liu, Chem. Commun., 1997, 161 DOI: 10.1039/A604578B

We here investigate polarimetric behavior of thick samples porcine liver, Intralipid, and microsphere-based tissue phantoms whose absorption scattering properties are matched.Using polarized light we measured reflection mode Mueller matrices derived linear/circular/total depolarization rates, based on polar decomposition.According to our results, exhibit greater rates in the backscattering geometry than liver sample.The enhanced polarization preservation differs from previous reports...

Hypofractionated partial breast irradiation (HPBI) involves treatment to the tumor using high doses per fraction. Recent advances in MRI-Linac solutions have potential being applied HPBI due gains soft tissue contrast of MRI; however, there are potentially deleterious effects magnetic field on dose distribution. The purpose this work is determine distribution for tumors a tangential beam arrangement (TAN), 5-beam intensity-modulated radiation therapy (IMRT), and volumetric modulated arc...

An amplifying quantum-cascade (QC) metasurface, the key component of QC vertical-external-cavity surface-emitting-laser (VECSEL), is studied as a function injected current density using reflection-mode terahertz time domain spectroscopy. Nearly perfect absorption measured at zero bias, which associated with transition from weak to strong coupling condition between metasurface resonance and an intersubband within material. increase in reflectance observed device biased, both due reduction...

This article introduces a silicon-based source that can radiate power from the lower end of terahertz (THz) spectrum into far-infrared region.The radiator consists millimeter-wave (mm-wave) oscillator drives PIN diode multiplier.The p-i-n diodes exhibit reverse recovery when driven strongly, and switches large amount current in short interval.This process is highly non-linear generates harmonic-rich waveform, which utilized here for higher harmonic generation.An on-chip folded dipole antenna...

To quantify and explain the backscatter dose effects for clinically relevant high atomic number materials being irradiated in presence of a 1.5 T transverse magnetic field.Interface were investigated using Monte Carlo simulation techniques. We used gpumcd (v5.1) geant4 (v10.1) this purpose. is commercial software written Elekta AB, MRI linac. Dose was scored cubic voxels side 1 0.5 mm, two different virtual phantoms dimensions 20 × cm 5 13.3 cm, respectively. A photon beam generated from...

Purpose This study aims to measure the surface dose on an anthropomorphic phantom for intensity‐modulated radiation therapy (IMRT) plans treated in a 1.5 T magnetic resonance (MR)‐Linac. Previous studies have used Monte Carlo programs simulate and recognized high as potential limiting factor MR‐Linac; however, our knowledge measurement clinical has not yet been published. Given novelty of MR‐Linac, it is important perform vivo measurements potentially dose‐limiting such when moving forward...

Terahertz (THz) external-cavity lasers based on quantum-cascade (QC) metasurfaces are emerging as widely-tunable, single-mode sources with the potential to cover 1--6 THz range in discrete bands milliwatt-level output power. By operating an ultra-short cavity a length order of wavelength, QC vertical-external-cavity surface-emitting-laser (VECSEL) architecture enables continuous, broadband tuning while producing high quality beam patterns and scalable power output. The methods challenges for...

Optimization is an important but relatively unexplored aspect of contrast-enhanced fluorescence imaging, since minimizing contrast agent usage reduces the associated cost and potential toxicity. In a previous study, authors developed quantitative experimental approach to optimize quantum dot (QD)-based imaging using homogenized liver as model tissue. this follow-up further extend validate eight different tissues five QDs emission wavelengths, introduce performance metrics, namely threshold...

DEVS has been proposed as the basic modeling and simulation framework for Model-Based System Engineering (MBSE) methodology that supports critical stages in top down design of complex systems. Here we propose a novel Markov Activity-Based Models to provide means experiment examine flows activities with behavioral elements. The approach allows comparing different seamless manner. Also adjustments models become possible would be costly harder maintain otherwise. With application MBSE mind, aim...

This paper presents a silicon-based source that can radiate power beyond 1 THz. A PIN diode frequency multiplier is driven by Colpitts oscillator designed at fundamental of 130 GHz. The exhibits sharp reverse recovery, which be exploited for strong harmonic generation in THz band. Wireless injection locking also demonstrated to lock the chip an external and reduce phase noise. design implemented GlobalFoundries 90 nm SiGe BiCMOS process has effective isotropic radiated (EIRP) 13 dBm 6%...

We demonstrated a broadband THz heterodyne receiver for astrophysics using Hot-Electron Bolometer (HEB) mixers based on high-T <inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">C</inf> superconducting MgB xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> and Quantum Cascade Laser (QCL) as local oscillator (LO). This detector will advance the state-of-the-art by allowing an operation at elevated temperature $(\sim 20\mathrm{K})$ providing...

In this talk, we present direct optical injection locking of a 2.5 THz quantum-cascade VECSEL with electronic source, namely diode frequency multiplier chain (FMC). The FMC outputs ~10 µW power and locks QC-VECSEL ~1 mW output over ~300 GHz bandwidth. high-resolution spectral properties the are monitored subharmonic mixer, locked linewidth Hz is observed signal-to-noise ratio ~40 dB, in good agreement injected signal.

The effects of optical feedback on a terahertz (THz) quantum-cascade vertical-external-cavity surface-emitting laser (QC-VECSEL) are investigated via self-mixing. A nominally single-mode 2.8 THz QC-VECSEL operating in continuous-wave is subjected to various conditions while monitoring variations its terminal voltage associated with Due large emitting aperture, and flat highly-reflective output coupler, the VECSEL architecture found be strongly susceptible feedback. Regions instability...

The effects of optical feedback on a terahertz (THz) quantum-cascade metasurface vertical-external-cavity surface-emitting laser (QC-VECSEL) are investigated via self-mixing. A single-mode 2.80 THz QC-VECSEL operating in continuous-wave is subjected to various conditions (i.e., strength, round-trip time, and angular misalignment) while variations its terminal voltage associated with self-mixing monitored. Due large radiating aperture near-Gaussian beam shape, we find that the strongly...

Harmonic and sub-harmonic RF injection locking is demonstrated in a terahertz (THz) quantum-cascade vertical-external-cavity surface-emitting laser (QC-VECSEL).By tuning the frequency around integer multiples submultiples of cavity round-trip frequency, different harmonic subharmonic orders can be excited same device.Modulation-dependent behavior device has been studied with recorded lasing spectral broadening bandwidths each case.In particular, results observation spectra over 200 GHz.A...

Optical injection locking of a metasurface quantum-cascade (QC) vertical-external-cavity surface-emitting laser (VECSEL) is demonstrated at 2.5 THz using Schottky diode frequency multiplier chain as the source. The spectral properties source are transferred to output with locked linewidth ∼1 Hz, measured by separate subharmonic mixer, and bandwidth ∼300 MHz achieved. large range enabled microwatt power levels available from modern multipliers. interplay between injected signal feedback...

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Polarization switchable terahertz quantum-cascade lasers are candidate sources for polarimetric imaging and sensing as their output polarization can be switched electrically without moving parts. We report on the importance of external cavity spectral properties purity a metasurface VECSEL.