Fe₂O₃ yolk-shell particle-based laccase biosensor for efficient detection of 2,6-dimethoxyphenol

Patel, Sanjay K.S.,Anwar, Muhammad Z.,Kumar, Ashok,Otari, Sachin V.,Pagolu, Ravi T.,Kim, Sang-Yong,Kim, In-Won,Lee, Jung-Kul Elsevier 2018 Biochemical engineering journal Vol.132 No.-

<P><B>Abstract</B></P> <P>The structural morphology and composition of a support play a key role in the performance of nanoparticle-based enzymatic biosensors. In the present study, the influence of different functional groups, including glutaraldehyde, 3-aminopropyltriethoxysilane, carbodiimide, cyano, and polyethyleneimine for the immobilization of laccase on synthesized Fe<SUB>2</SUB>O<SUB>3</SUB> yolk-shell and commercially available Fe<SUB>2</SUB>O<SUB>3</SUB>, SrFe<SUB>12</SUB>O<SUB>19</SUB>, and Y<SUB>3</SUB>Fe<SUB>5</SUB>O<SUB>12</SUB> particles was analyzed. Glutaraldehyde-activated particles showed higher laccase activity after immobilization and higher relative detection currents for 2,6-dimethoxyphenol (2,6-DMP). The multi-shelled structural morphology of Fe<SUB>2</SUB>O<SUB>3</SUB> yolk-shell particles significantly improved the biosensing properties of immobilized laccase compared to that of spherical pure Fe<SUB>2</SUB>O<SUB>3</SUB> and composite SrFe<SUB>12</SUB>O<SUB>19</SUB> and Y<SUB>3</SUB>Fe<SUB>5</SUB>O<SUB>12</SUB> particles. The prepared biosensors showed high selectivity towards 2,6-DMP, with a sensitivity of 452 μA/mM/cm<SUP>2</SUP>. Under optimum conditions, the linear ranges of detection were as follows: 2,6-DMP (0.025–750 μM), guaiacol (0.10–250 μM), pyrogallol (0.25–250 μM), and 3,4-dihydroxy-<SMALL>L</SMALL>-phenylalanine (1.0–125 μM), with limit of detection values of 0.010, 0.052, 0.093, and 0.273 μM, respectively. Laccase immobilized on bio-friendly multi-shelled Fe<SUB>2</SUB>O<SUB>3</SUB> yolk-shell particles showed a broad linear range of detection, the lowest limit of detection, high sensitivity and stability, good reproducibility, anti-interference and recovery, and insignificant inhibition by laccase inhibitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fe<SUB>2</SUB>O<SUB>3</SUB> yolk-shell particles were used to prepare laccase biosensors. </LI> <LI> Particle composition and morphology exhibited significant variation in biosensing. </LI> <LI> Fe<SUB>2</SUB>O<SUB>3</SUB> yolk-shell biosensor showed a high selectivity towards 2,6-dimethoxyphenol. </LI> <LI> A broad linear range of detection with the lowest limit of detection (0.01 μM) was observed. </LI> </UL> </P>

Effects of operating parameters on the production of barium sulfate nanoparticles in stirred media mill

Chetan M. Patel,Mousumi Chakraborty,Z.V.P. Murthy 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.4

A systematic study on wet grinding of barium sulfate to produce nanoparticles (<50 nm) was performed in a stirred media mill. The suspension stabilization by pH adjustment and dispersants addition were investigated using zeta potential measurement and the multiple light scattering methods. It was found that particle size reduction requires use of dispersant (sodium salt of polyacrylic acid). The optimum amount of dispersant concentration was determined to be 2% by weight. Further, the influence of pinlength was found to improve the performance. The influence of solids mass fraction, grinding media diameter on pH variation and final size were evaluated.

Enhancement of stirred media mill performance by a new mixed media grinding strategy

Chetankumar M. Patel,Mousumi Chakraborty,Z.V.P. Murthy 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

Wet grinding experiments were carried out to optimize the cost of grinding media and energy consumption by adding different amount of finer to coarser grinding media. The effects of amount of finer media and finer to coarser grinding media size ratio were investigated. Much smaller product particle sizes were obtained with lesser amount of energy consumption by mixed media grinding. Nanogrinding performance was evaluated by mixing grinding media of different sizes based on the stress energy model. Rheological analysis of ground nanosuspension was conducted to elucidate the role of finer grinding media to improve the wet grinding process.

Different 2D materials based polyetherimide mixed matrix membranes for CO2/N2 separation

Ashwin R. Kamble,Chetan M. Patel,Z.V.P. Murthy 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.81 No.-

Keeping the global warming and climate change issues in mind, various efforts are being taking placeworldwide to separate/capture CO2 fromflue gas mixture in order to reduce its emission in theatmosphere. Therefore, in this work, we improve the gas transport properties of polyetherimide (PEI)membrane for CO2/N2 separation by embedding three differentfillers of two-dimensional materials suchas graphene oxide (GO), molybdenum disulfide (MoS2), and hexagonal boron nitride (h-BN) in its matrix. Additionally, the effect of different weight fraction (0.5,1.5, and 2.5 wt.%) of thesefillers on the CO2/N2 gasseparation performance have been investigated. Membrane morphology, variation in the chemical bondsand membrane surface roughness were observed by employing Field Emission Gun Scanning ElectronMicroscopy (FEG-SEM), Fourier Transform Infrared Spectroscopy (FTIR), and Atomic Force Microscopy(AFM) analysis. Results obtained from the gas permeation showed that PEI embodied with GO exhibitedhigher gas permeation compared to when embodied with h-BN and MoS2. However, the maximumseparation was achieved with MoS2 particles.

Impact of Universal Suicide Risk Screening in a Pediatric Emergency Department: A Discrete Event Simulation Approach

Kenneth W. McKinley,Kelly N. Z. Rickard,Finza Latif,Theresa Wavra,Julie Berg,Sephora Morrison,James M. Chamberlain,Shilpa J. Patel 대한의료정보학회 2022 Healthcare Informatics Research Vol.28 No.1

Objectives: The aim of this study was to use discrete event simulation (DES) to model the impact of two universal suiciderisk screening scenarios (emergency department [ED] and hospital-wide) on mean length of stay (LOS), wait times, andoverflow of our secure patient care unit for patients being evaluated for a behavioral health complaint (BHC) in the ED of alarge, academic children’s hospital. Methods: We developed a conceptual model of BHC patient flow through the ED, incorporatinganticipated system changes with both universal suicide risk screening scenarios. Retrospective site-specific patienttracking data from 2017 were used to generate model parameters and validate model output metrics with a random 50/50split for derivation and validation data. Results: The model predicted small increases (less than 1 hour) in LOS and waittimes for our BHC patients in both universal screening scenarios. However, the days per year in which the ED experiencedsecure unit overflow increased (existing system: 52.9 days; 95% CI, 51.5–54.3 days; ED: 94.4 days; 95% CI, 92.6–96.2 days;and hospital-wide: 276.9 days; 95% CI, 274.8–279.0 days). Conclusions: The DES model predicted that implementation of eitheruniversal suicide risk screening scenario would not severely impact LOS or wait times for BHC patients in our ED. However,universal screening would greatly stress our existing ED capacity to care for BHC patients in secure, dedicated patientareas by creating more overflow.

Preparation, characterization and application of GO-TiO2/PVC mixed matrix membranes for improvement in performance

Jainesh H. Jhaveri,Chetan M. Patel,Z.V.P. Murthy 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.52 No.-

Poly vinyl chloride (PVC) membranes are known for their low cost as well as good mechanical, thermaland chemical stability. However, the inherent hydrophobicity of the PVC material leads to fouling ofmembrane. Thus, in this paper, we have attempted to use GO-TiO2 nanosheets-blended PVC membranes. GO-TiO2 nanosheets are blended in the casting solution containing PVC and polyvinylpyrrolidone (PVP). Filtration experiments show that blending of GO-TiO2 sheets enhanced the permeateflux while keepingthe rejection of humic acid almost same. The results are supported by characterizations like SEM, EDX,TEM, AFM, XRD and contact angle measurements.

Inhibition of Neurogenic Inflammatory Pathways Associated with the Reduction in Discogenic Back Pain

Canseco Jose A.,Levy Hannah A.,Karamian Brian Abedi,Blaber Olivia,Chang Michael,Patel Neil,Curran John,Hilibrand Alan S.,Schroeder Gregory D.,Vaccaro Alexander R.,Markova Dessislava Z.,Surrey David E. 대한척추외과학회 2023 Asian Spine Journal Vol.17 No.6

Study Design: Retrospective cohort study.Purpose: This study aimed to determine whether the initiation of anti-calcitonin gene-related peptide (CGRP inhibitor) medication therapy for migraines was also associated with improvements in back/neck pain, mobility, and function in a patient population with comorbid degenerative spinal disease and migraine.Overview of Literature: CGRP upregulates pro-inflammatory cytokines such as tumor necrosis factor-α, interleukin-6, brain-derived neurotrophic factor, and nerve growth factor in spinal spondylotic disease, which results in disc degeneration and sensitization of nociceptive neurons. Although CGRP inhibitors can quell neurogenic inflammation in migraines, their off-site efficacy as a therapeutic target for discogenic back/neck pain conditions remains unknown.Methods: All adult patients diagnosed with spinal spondylosis and migraine treated with CGRP inhibitors at a single academic institution between 2017 and 2020 were retrospectively identified. Patient demographic and medical data, follow-up duration, migraine severity and frequency, spinal pain, functional status, and mobility before and after the administration of CGRP inhibitors were collected. Paired univariate analysis was conducted to determine significant changes in spinal pain, headache severity, and headache frequency before and after the administration of CGRP inhibitors. The correlation between changes in the spinal pain score and functional or mobility improvement was assessed with Spearman’s rho.Results: In total, 56 patients were included. The mean follow-up time after the administration of CGRP inhibitors was 123 days for spinal pain visits and 129 days for migraine visits. Back/neck pain decreased significantly (<i>p</i> <0.001) from 6.30 to 4.36 after starting CGRP inhibitor therapy for migraine control. As recorded in the spine follow-up notes, 25% of patients experienced a functional improvement in the activities of daily living, and 17.5% experienced mobility improvement while taking CGRP inhibitors. Change in back/ neck pain moderately correlated (ρ=−0.430) with functional improvement but was not correlated with mobility improvement (ρ=−0.052).Conclusions: Patients taking CGRP inhibitors for chronic migraines with comorbid degenerative spinal conditions experienced significant off-target reduction of back/neck pain.