6 research outputs found

    Quantifying morphology of sands using 3D imaging

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    Particle morphology plays a significant role in influencing engineering behavior of granular materials. Surface texture, roundness, and sphericity represent distinct multiscale measures needed to fully describe particle morphology. Most studies reported in the literature rely on two-dimensional (2D) projected images of particles with a few three-dimensional (3D) images that mostly focused on relatively large-size aggregate samples. In this paper, 3D synchrotron microcomputed tomography (SMT) was used to acquire high-resolution images of glass beads, F-35 Ottawa sand, #1 dry glass sand, GS#40 Columbia sand, Toyoura sand, and Hostun RF sand. New roundness and sphericity indexes are proposed and calculated for the samples based on 3D measurements of surface area, volume, and three orthogonal diameters of particles. In addition, the surface texture of particles were measured using optical interferometry technique. The measurements reported in this paper can serve as a good source for other researchers working on sands to build on these intrinsic particle properties to link engineering behavior of sands to their morphology. 2014 American Society of Civil Engineers.National Science FoundationScopu

    Online, Absolute Quantitation of Propranolol from Spatially Distinct 20- and 40-μm Dissections of Brain, Liver, and Kidney Thin Tissue Sections by Laser Microdissection–Liquid Vortex Capture–Mass Spectrometry

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    Spatial resolved quantitation of chemical species in thin tissue sections by mass spectrometric methods has been constrained by the need for matrix-matched standards or other arduous calibration protocols and procedures to mitigate matrix effects (e.g., spatially varying ionization suppression). Reported here is the use of laser “cut and drop” sampling with a laser microdissection-liquid vortex capture electrospray ionization tandem mass spectrometry (LMD-LVC/ESI-MS/MS) system for online and absolute quantitation of propranolol in mouse brain, kidney, and liver thin tissue sections of mice administered with the drug at a 7.5 mg/kg dose, intravenously. In this procedure either 20 μm × 20 μm or 40 μm × 40 μm tissue microdissections were cut and dropped into the flowing solvent of the capture probe. During transport to the ESI source drug related material was completely extracted from the tissue into the solvent, which contained a known concentration of propranolol-<i>d</i><sub>7</sub> as an internal standard. This allowed absolute quantitation to be achieved with an external calibration curve generated from standards containing the same fixed concentration of propranolol-<i>d</i><sub>7</sub> and varied concentrations of propranolol. Average propranolol concentrations determined with the laser “cut and drop” sampling method closely agreed with concentration values obtained from 2.3 mm diameter tissue punches from serial sections that were extracted and quantified by HPLC/ESI-MS/MS measurements. In addition, the relative abundance of hydroxypropranolol glucuronide metabolites were recorded and found to be consistent with previous findings

    Integrated molecular and multiparametric MRI mapping of high-grade glioma identifies regional biologic signatures

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    Abstract Sampling restrictions have hindered the comprehensive study of invasive non-enhancing (NE) high-grade glioma (HGG) cell populations driving tumor progression. Here, we present an integrated multi-omic analysis of spatially matched molecular and multi-parametric magnetic resonance imaging (MRI) profiling across 313 multi-regional tumor biopsies, including 111 from the NE, across 68 HGG patients. Whole exome and RNA sequencing uncover unique genomic alterations to unresectable invasive NE tumor, including subclonal events, which inform genomic models predictive of geographic evolution. Infiltrative NE tumor is alternatively enriched with tumor cells exhibiting neuronal or glycolytic/plurimetabolic cellular states, two principal transcriptomic pathway-based glioma subtypes, which respectively demonstrate abundant private mutations or enrichment in immune cell signatures. These NE phenotypes are non-invasively identified through normalized K2 imaging signatures, which discern cell size heterogeneity on dynamic susceptibility contrast (DSC)-MRI. NE tumor populations predicted to display increased cellular proliferation by mean diffusivity (MD) MRI metrics are uniquely associated with EGFR amplification and CDKN2A homozygous deletion. The biophysical mapping of infiltrative HGG potentially enables the clinical recognition of tumor subpopulations with aggressive molecular signatures driving tumor progression, thereby informing precision medicine targeting
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