Proton density fat fraction: magnetic resonance imaging applications beyond the liver

Magnetic resonance imaging-proton density fat fraction (MRI-PDFF) is an emerging quantitative imaging biomarker that accurately measures the fat fraction of tissue by correcting factors influencing magnetic resonance signal intensity. Beyond fat quantification, it also measures R2* which is a direct measure of iron concentration. The utilization of MRI-PDFF in liver diseases is well established. In the present review, we focused on applications of MRI-PDFF in different body areas including pancreas, bone, muscle, spleen, testis, visceral, and subcutaneous adipose tissue. Future studies can enable tracking of quantitative fat fraction changes in different organs simultaneously, which can be critical in understanding fat metabolism

Ensemble Analysis of Angiogenic Growth in Three-Dimensional Microfluidic Cell Cultures

We demonstrate ensemble three-dimensional cell cultures and quantitative analysis of angiogenic growth from uniform endothelial monolayers. Our approach combines two key elements: a micro-fluidic assay that enables parallelized angiogenic growth instances subject to common extracellular conditions, and an automated image acquisition and processing scheme enabling high-throughput, unbiased quantification of angiogenic growth. Because of the increased throughput of the assay in comparison to existing three-dimensional morphogenic assays, statistical properties of angiogenic growth can be reliably estimated. We used the assay to evaluate the combined effects of vascular endothelial growth factor (VEGF) and the signaling lipid sphingoshine-1-phosphate (S1P). Our results show the importance of S1P in amplifying the angiogenic response in the presence of VEGF gradients. Furthermore, the application of S1P with VEGF gradients resulted in angiogenic sprouts with higher aspect ratio than S1P with background levels of VEGF, despite reduced total migratory activity. This implies a synergistic effect between the growth factors in promoting angiogenic activity. Finally, the variance in the computed angiogenic metrics (as measured by ensemble standard deviation) was found to increase linearly with the ensemble mean. This finding is consistent with stochastic agent-based mathematical models of angiogenesis that represent angiogenic growth as a series of independent stochastic cell-level decisions

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

5,17-bisazocalix[4]arenes

Three novel chromogenic cone azocalix[4]arenes 5a-c, which have cavity and the azo groups as metal-binding sites and as coloration sites were synthesized. They were studied by the liquid-liquid extraction of selected metal cations (Sr2+, Ag+, Hg+, Hg2+, Co2+, Ni2+, Cu2+, Zn2+, Cr3+, Al3+). Through examination of the extraction, a novel selectivity of these compounds toward Hg2+ cations has been determined. Besides, it has been also found that azocalix[4]arene 5c is highly sensitive to acid-base titration, which can be detected by the naked eye

para-substituted phenylazocalix[4]arene containing mono ethyl ester unit

In the present study, six new azocalix[4]arenes have been synthesized by reacting calix[4]arene with p-substituted aniline and ethyl bromoacetate. Characterization of these compounds has been used by elemental analyses, UV Vis, FT-IR and H-1 NMR spectroscopic studies. Their phase transfer studies have been performed by using liquid liquid extraction procedure. With respect to the chromogenic behavior of hosts upon metal ion complexation, mono ethyl ester azocalix[4]arene derivatives have shown a significant selectivity toward Hg2+ and Hg+ over many other cations. It has been deduced that these new compounds are selective ionophores toward metal cations (Na+, K+, Sr2+, Ag+, Hg+, Hg2+, Co2+, Ni2+, Cu2+, Zn2+, Cr3+, Al3+ and La3+). (C) 2014 Elsevier Ltd. All rights reserved

Measuring the Performance of Post-Quantum Cryptography on Embedded Systems

Post-quantum cryptography is becoming more important as quantum computers get closer to becoming part of our daily lives. Understanding this need, the NIST organized a competition-based system in 2019 to find public key encryption and digital signature algorithms that could be used in future standardizations. Currently the competition is in the third round. Our project will consist of using and modifying the finalist’s code to compare the timing between Linux and the Raspberry Pi 4 Model B

The Impact Of Standardized Patients' Feedback On The Students' Motivational Levels

In this study, we focused on the impact of standardized patients' feedback on the motivational levels of learners for learning communication skills. A control group post-test design was used. The students had two standardized patient encounters in addition to training and debriefing sessions. The students in the study group received face-to-face feedback after the first encounters; but not the control group. We used the motivation dimension of Motivated Strategies for Learning Questionnaire. The standardized patients' feedback effected students' motivational levels. The students who received feedback had lower levels of test anxiety, and higher levels of self-efficacy. (C) 2009 Elsevier Ltd. All rights reserved

IMMOBILIZATION OF UREASE INTO CARBOXYMETHYLCELLULOSE - GELATIN SYSTEM

In the present work carboxymethylcellulose (CMC) and CMC-gelatin were used as carrier systems for urease immobilization. Immobilization was based on the formation of insoluble salts of CMC and gelatin with chromium(111) ions. Chromium(111) acetate (CA) and chromium(111) sulfate (CS) were used for this purpose and their effect on urease activity was investigated. The activities of immobilized urease using pure and CMC-gelatin carrier systems were compared. Urease activity was determined by using Berthelot method. Reuse number, pH, enzyme and cross linker concentrations and the incubation period were the factors taken into account in this investigation. Activity of immobilized enzymes were found to be stable for at least 2 months and 16-24 usage. Immobilization percentage obtained under optimum conditions was 40%

STUDIES ON IMMOBILIZATION OF UREASE IN GELATIN BY CROSS-LINKING

Urease enzyme was immobilized in photographic gelatin by chemical cross-linking using formaldehyde, glutaraldehyde and chromium (III) acetate. The effects of enzyme and cross-linker concentrations, temperature, incubation time and pH on urea hydrolysis were investigated. Effect of reuse on the activity of immobilized enzyme was also studied. Glutaraldehyde (0.004 M) was the most suitable cross-linker; relative activities within 2.5 months after 24 reuses were stable (about 78%)