Exploring the role of antigen-presenting cancer-associated fibroblasts and CD74 on the pancreatic ductal adenocarcinoma tumor microenvironment.

Pancreatic ductal adenocarcinoma (PDAC) has proven to be a formidable cancer primarily due to its tumor microenvironment (TME). This highly desmoplastic, hypoxic, and pro-inflammatory environment has not only been shown to facilitate the growth and metastasis of PDAC but has also displayed powerful immunosuppressive capabilities. A critical cell involved in the development of the PDAC TME is the fibroblast, specifically the antigen-presenting cancer-associated fibroblast (apCAF).

Nanoporous antireflection coating for high-temperature applications in the infrared.

Antireflection (AR) coatings are essential to the performance of optical systems; without them, surface reflections increase significantly at steep angles and become detrimental to the functionality. AR coatings apply to a wide range of applications from solar cells and laser optics to optical windows. Many times, operational conditions include high temperatures and steep angles of incidence (AOIs).

Supercontinuum-laser diffuse reflectance spectroscopy in conjunction with an extended Kubelka-Munk model-a methodology for determination of temperature-dependent quantum efficiency in highly scattering and fluorescent media.

Temperature-dependent diffuse reflectance measurements on Cr-doped -alumina monoliths have been performed using supercontinuum-laser illumination and -laser heating. These measurements have been interpreted using an extended Kubelka-Munk (K-M) model describing diffuse-light propagation in highly scattering and fluorescent media to assess the temperature dependence of fluorescence quantum efficiency. Analysis of experimental results has provided a qualitative understanding of the temperature-dependent conditions for model applicability and also suggests methods for using supercontinuum-laser diffuse reflectance spectroscopy for detection of unknown fluorescent dopants.

Experimental characterization and physics-based modeling of the temperature-dependent diffuse reflectance of plasma-sprayed NdZrO in the near to short-wave infrared.

Supercontinuum-laser illumination in conjunction with CO-laser heating has been implemented to measure the near to short-wave infrared (970-1660 nm) diffuse reflectance of plasma-sprayed NdZrO as a function of temperature. Owing to the broadband nature of this experimental technique, the diffuse reflectance of plasma-sprayed NdZrO has been measured at many wavelengths and has been shown to decrease with increasing temperature. A physics-based model for diffuse reflectance predicated on the crystal/electronic band structure of highly scattering semiconductor materials has been constructed to interpret the results of these measurements.

Temperature-dependent diffuse reflectance spectroscopy of plasma-sprayed Cr-doped α-alumina using supercontinuum laser illumination and CO laser heating.

This study presents results for the high-temperature (up to 1550 K) optical properties of polycrystalline Cr-doped α-alumina materials. Diffuse reflectance spectra in the wavelength range of 510-840 nm are presented as a function of temperature to illustrate changes to the optical behavior of these materials including a previously unreported thermally activated splitting of the U-band absorption (A4→T4) in octahedrally coordinated Cr. Measurements were made using a unique laser-based approach for high-temperature solid-state spectroscopy, involving front-side supercontinuum laser illumination and back-side CO laser heating.

Transmittance derived line width and line shift in polycrystalline Nd:YAG.

Temperature dependent transmittance derived line width and line shift measurements are conducted on polycrystalline 1% and 6% Nd doped YAG in the 293 K-473 K range. A single crystal temperature dependent line width model is adapted for polycrystalline YAG. Comparison between line width measurement techniques was conducted, and the transmittance method is preferred for ground state line width measurements.

Lidar measurements of solid rocket propellant fire particle plumes.

This paper presents the first, to our knowledge, direct measurement of aerosol produced by an aluminized solid rocket propellant (SRP) fire on the ground. Such fires produce aluminum oxide particles small enough to loft high into the atmosphere and disperse over a wide area. These results can be applied to spacecraft launchpad accidents that expose spacecraft to such fires; during these fires, there is concern that some of the plutonium from the spacecraft power system will be carried with the aerosols.

Desorption of hydrogen from light metal hydrides: concerted electronic rearrangement and role of H···H interactions.

A theoretical study of the desorption of hydrogen from rhombic Group 1 metal hydride dimers reveals a concerted reorganisation of the electron density for the M-H and H-H moieties as the reaction coordinate is traversed and a closed-shell H···H interaction evolves into a covalent H2 bond. The central role played by homopolar dihydrogen bonding in this process is revealed and analysed.

Backscatter signatures of biological aerosols in the infrared.

To develop a deeper understanding of the optical signatures of both biological aerosols and potential interferents, we made field measurements of optical cross sections and compared them to model-based predictions. We measured aerosol cross sections by conducting a hard-target calibration of a light detection and ranging system (LIDAR) based on the Frequency Agile Laser (FAL). The elastic backscatter cross sections are estimated at 19 long-wave infrared (LWIR) wavelengths spanning the range from 9.

Chamber lidar measurements of biological aerosols.

In order to determine the performance of standoff sensors against agents, there is a need to develop methods to characterize the optical properties of biological warfare agents. The goal of this work is to develop a methodology that would allow the characterization of agent optical cross sections from the UV to the longwave IR. The present work demonstrates an optical measurement architecture based on lidar technology, allowing the measurement of backscatter and depolarization ratio from biological aerosols (either simulants or agents) released in a refereed, 1m chamber.

Self-inducing shape memory geometric cues embedded within smart hydroxyapatite-based biomimetic matrices.

Background: The authors investigated in nonhuman primates (Papio ursinus) whether it is possible to engineer biomimetic matrices that induce the differentiation of osteoblastic cells expressing selected osteogenic mRNA species of the transforming growth factor (TGF)-beta superfamily.

Methods: Four types of sintered hydroxyapatite and biphasic hydroxyapatite/tricalcium phosphate bioceramics were evaluated as osteoinductive self-inducing biomimetic matrices. Matrices were fabricated with a series of repetitive concavities that initiate the induction of bone formation as a secondary response.

Particle shape as revealed by spectral depolarization.

Through a series of numerical simulations we explore some scatter effects due to nonspherical particles. Specifically, we examine the link between the aspect ratio of randomly oriented, prolate spheroidal particles and the resulting linear depolarization of the scattered light in the forward and backscatter directions. The particular objective is to detect the presence of randomly oriented particles that have a systematic size and aspect ratio.

Modeling of the frequency- and temperature-dependent absorption coefficient of long-wave-infrared (2-25 microm) transmitting materials.

A semiempirical multiphonon model based on quantum-mechanical oscillators under a Morse potential is applied to the absorption coefficient of far-infrared transmitting materials. Known material properties are combined with absorption coefficient data to fit the empirical parameters of the model. This provides an accurate means of predicting the intrinsic absorption of the materials in their multiphonon regions.