Processing and Specimen Thickness to Grain Size (t/d) Ratio Effects on Tensile Behaviour and Microformability of Copper Foils

Javed S. Ibrahim ,Rohit T. Mathew,M. J. N. V. Prasad,K. Narasimhan 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.10

Owing to high heat flux ability and good mechanical strength, copper has been used for micro-electro-mechanical systems(MEMS) components with dimensions in micrometers processed by electrochemical methods. In the present study, finegrained copper foils of different thicknesses and grain sizes produced by pulsed electrodeposition under different controlledcurrent densities were used to investigate the effect of total number of grains across thickness of foil on its tensile responseand formability. For a comparative study, commercially available rolled Cu foils were also used. Vacuum annealing wasemployed to obtain a wide range of fully recrystallized grain sizes within same thickness of the foils. Detailed microstructuralcharacterization was carried out using scanning electron microscope attached with electron backscattered diffraction detector. The foils were subjected to uniaxial tensile testing and formability testing using a miniaturized Nakazima test setup. Asanticipated, finer the grain size higher was the yield strength. However, the strength of copper reduced with decreasing thetotal number of grains across thickness of the foil. The electrodeposited Cu foil exhibited relatively higher strength levelsbut reduced tensile ductility along with decreased strain hardening ability compared to the fully recrystallized Cu foils havingsimilar grain sizes. Furthermore, the number of grains across thickness and the prior history of foils played significantrole on the shape and trend in variation of the forming limit curve of Cu. An α-fiber (< 110 >) texture evolved in Cu duringdeformation and its volume fraction strengthened under biaxial deformation conditions.

Selected aryl thiosemicarbazones as a new class of multi-targeted monoamine oxidase inhibitors

Mathew, Bijo,Baek, Seung Cheol,Grace Thomas Parambi, Della,Pil Lee, Jae,Joy, Monu,Annie Rilda, P. R.,Randev, Rugma V.,Nithyamol, P.,Vijayan, Vijitha,Inasu, Sini T.,Mathew, Githa Elizabeth,Lohidakshan, The Royal Society of Chemistry 2018 MedChemComm Vol.9 No.11

<P>A series of 13 phenyl substituted thiosemicarbazones (SB1-SB13) were synthesized and evaluated for their inhibitory potential towards human recombinant monoamine oxidase A and B (MAO-A and MAO-B, respectively) and acetylcholinesterase. The solid state structure of SB4 was ascertained by the single X-ray diffraction technique. Compounds SB5 and SB11 were potent for MAO-A (IC50 1.82 ± 0.14) and MAO-B (IC50 0.27 ± 0.015 μM), respectively. Furthermore, SB11 showed a high selectivity index (SI > 37.0) for MAO-B. The effects of fluorine orientation revealed that SB11 (<I>m</I>-fluorine) showed 28.2 times higher inhibitory activity than SB12 (<I>o</I>-fluorine) against MAO-B. Furthermore, inhibitions by SB5 and SB11 against MAO-A and MAO-B, respectively, were recovered to near reference levels in reversibility experiments. Both SB5 and SB11 showed competitive inhibition modes, with <I>K</I>i values of 0.97 ± 0.042 and 0.12 ± 0.006 μM, respectively. These results indicate that SB5 and SB11 are selective, reversible and competitive inhibitors of MAO-A and MAO-B, respectively. Compounds SB5, SB7 and SB11 showed moderate inhibition against acetylcholinesterase with IC50 values of 35.35 ± 0.47, 15.61 ± 0.057 and 26.61 ± 0.338 μM, respectively. Blood-brain barrier (BBB) permeation was studied using the parallel artificial membrane permeation assay (PAMPA) method. Molecular docking studies were carried out using AutoDock 4.2.</P>

Comparative analysis of noise from three Falcon 9 launches

Mathews, Logan T.,Gee, Kent L.,Hart, Grant W.,Rasband, Reese D.,Novakovich, Daniel J.,Irarrazabal, Francisco I.,Vaughn, Aaron B.,Nelson, Pauline The Acoustical Society of Korea 2020 韓國音響學會誌 Vol.39 No.4

This study investigates the far-field noise from three Falcon 9 vehicle launches from Vandenberg Air Force Base, CA, USA, as measured from the same location within the nearby community of Lompoc. The overall sound pressure levels for the three launches are shown to be similar, but some differences in the early launch period are thought to be weather-related. The peak directivity angle in overall level is approximately 65 deg, which is consistent with horizontally-fired, static rocket data. For the third launch, waveforms and spectra are analyzed for different events during the launch sequence. The measured spectral bandwidth decreases with time, but spectral levels remain above the ambient noise throughout the main-engine firing. Additionally, late-launch phenomena observed in the data appear to be correlated with main-engine cutoff and second-stage engine start.

Endoscopic Management of Large Peripancreatic Fluid Collections in Two Pediatric Patients by Endoscopic Ultrasound-guided Transmural Drainage

Leonard T. Walsh,Andrew Groff,Abraham Mathew,Matthew T. Moyer 대한소아소화기영양학회 2020 Pediatric gastroenterology, hepatology & nutrition Vol.23 No.1

The incidence of acute pancreatitis (AP) has increased in the pediatric population over the past few decades and it stands to follow that the complications of severe AP, including symptomatic pancreatic fluid collections (PFCs) will increase as well. In adults, the therapeutic options for this situation have undergone a dramatic evolution from mainly surgical approaches to less invasive endoscopic approaches, mainly endoscopic ultrasound-guided transmural drainage (EUS-TD) followed be direct endoscopic necrosectomy if needed. This has proven safe and effective in adults; however, this approach has not been well studied or reported in pediatric populations. Here we demonstrate that EUS-TD seems to offer a safe, efficacious and minimally invasive approach to the management of large PFCs in pediatric patients by reviewing two representative cases at our institution.

Development of a decision-support tool to quantify authorship contributions in clinical trial publications

Sam T. Mathew,Habeeb Ibrahim Abdul Razack,Prasanth Viswanathan 한국과학학술지편집인협의회 2022 Science Editing Vol.9 No.1

Purpose: This study aimed to develop a decision-support tool to quantitatively determine authorship in clinical trial publications. Methods: The tool was developed in three phases: consolidation of authorship recommendations from the Good Publication Practice (GPP) and International Committee of Medical Journal Editors (ICMJE) guidelines, identifying and scoring attributes using a 5-point Likert scale or a dichotomous scale, and soliciting feedback from editors and researchers. Results: The authorship criteria stipulated by the ICMJE and GPP recommendations were categorized into 2 Modules. Criterion 1 and the related GPP recommendations formed Module 1 (sub-criteria: contribution to design, data generation, and interpretation), while Module 2 was based on criteria 2 to 4 and the related GPP recommendations (sub-criteria: contribution to manuscript preparation and approval). The two modules with relevant sub-criteria were then differentiated into attributes (n = 17 in Module 1, n = 12 in Module 2). An individual contributor can be scored for each sub-criterion by summing the related attribute values; the sum of sub-criteria scores constituted the module score (Module 1 score: 70 [contribution to conception or design of the study, 20; data acquisition, 7; data analysis, 27; interpretation of data, 16]; Module 2 score: 50 [content development, 27; content review, 18; accountability, 5]). The concept was integrated into Microsoft Excel with adequate formulae and macros. A threshold of 50% for each sub-criterion and each module, with an overall score of 65%, is predefined as qualifying for authorship. Conclusion: This authorship decision-support tool would be helpful for clinical trial sponsors to assess and provide authorship to deserving contributors.

Pion production via proton synchrotron radiation in strong magnetic fields in relativistic field theory: Scaling relations and angular distributions

Maruyama, T.,Cheoun, M.K.,Kajino, T.,Mathews, G.J. North-Holland Pub. Co 2016 Physics letters: B Vol.757 No.-

<P>We study pion production by proton synchrotron radiation in the presence of a strong magnetic field when the Landau numbers of the initial and final protons are n(i, f) similar to 10(4)-10(5). We find in our relativistic field theory calculations that the pion decay width depends only on the field strength parameter which previously was only conjectured based upon semi-classical arguments. Moreover, we also find new results that the decay width satisfies a robust scaling relation, and that the polar angular distribution of emitted pion momenta is very narrow and can be easily obtained. This scaling implies that one can infer the decay width in more realistic magnetic fields of 10(15) G, where n(i, f) similar to 10(12)-10(13), from the results for n(i, f) similar to 10(4)-10(5). The resultant pion intensity and angular distributions for realistic magnetic field strengths are presented and their physical implications discussed. (C) 2016 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Funded by SCOAP(3).</P>

Endoscopic Management of Large Peripancreatic Fluid Collections in Two Pediatric Patients by Endoscopic Ultrasound-guided Transmural Drainage

Walsh, Leonard T.,Groff, Andrew,Mathew, Abraham,Moyer, Matthew T. The Korean Society of Pediatric Gastroenterology 2020 Pediatric gastroenterology, hepatology & nutrition Vol.23 No.1

The incidence of acute pancreatitis (AP) has increased in the pediatric population over the past few decades and it stands to follow that the complications of severe AP, including symptomatic pancreatic fluid collections (PFCs) will increase as well. In adults, the therapeutic options for this situation have undergone a dramatic evolution from mainly surgical approaches to less invasive endoscopic approaches, mainly endoscopic ultrasound-guided transmural drainage (EUS-TD) followed be direct endoscopic necrosectomy if needed. This has proven safe and effective in adults; however, this approach has not been well studied or reported in pediatric populations. Here we demonstrate that EUS-TD seems to offer a safe, efficacious and minimally invasive approach to the management of large PFCs in pediatric patients by reviewing two representative cases at our institution.

Diffuse Intrinsic Pontine Glioma : Clinical Features, Molecular Genetics, and Novel Targeted Therapeutics

Mathew, Ryan K.,Rutka, James T. The Korean Neurosurgical Society 2018 Journal of Korean neurosurgical society Vol.61 No.3

Diffuse intrinsic pontine glioma (DIPG) is a deadly paediatric brain cancer. Transient response to radiation, ineffective chemotherapeutic agents and aggressive biology result in rapid progression of symptoms and a dismal prognosis. Increased availability of tumour tissue has enabled the identification of histone gene aberrations, genetic driver mutations and methylation changes, which have resulted in molecular and phenotypic subgrouping. However, many of the underlying mechanisms of DIPG oncogenesis remain unexplained. It is hoped that more representative in vitro and preclinical models-using both xenografted material and genetically engineered mice-will enable the development of novel chemotherapeutic agents and strategies for targeted drug delivery. This review provides a clinical overview of DIPG, the barriers to progress in developing effective treatment, updates on drug development and preclinical models, and an introduction to new technologies aimed at enhancing drug delivery.

Production of chiral β-amino acids using ω-transaminase from Burkholderia graminis

Mathew, S.,Bea, H.,Nadarajan, S.P.,Chung, T.,Yun, H. Elsevier Science Publishers 2015 Journal of biotechnology Vol.196 No.-

<P>Optically pure beta-amino acids are of high pharmacological significance since they are used as key ingredients in many physiologically active compounds. Despite a number of enzymatic routes to these compounds, an efficient synthesis of beta-amino acids continues to pose a major challenge for researchers. omega-Transaminase has emerged as an important class of enzymes for generating amine compounds. However, only a few omega-transaminases have been reported so far which show activity towards aromatic beta-amino acids. In this study, (S)-omega-transaminase from Burkholderia graminis C4D1M has been functionally characterized and used for the production of chiral aromatic beta-amino acids via kinetic resolution. The enzyme showed a specific activity of 3.1 U/mg towards rac-beta-phenylalanine at 37 degrees C. The K-m and K-cat values of this enzyme towards rac-beta-phenylalanine with pyruvate as the amino acceptor were 2.88 mM and 91.57 min(-1) respectively. Using this enzyme, racemic beta-amino acids were kinetically resolved to produce (R)-beta-amino acids with an excellent enantiomeric excess (> 99%) and similar to 50% conversion. Additionally, kinetic resolution of aromatic beta-amino acids was performed using benzaldehyde as a cheapamino acceptor. (C)2015 Elsevier B.V. All rights reserved.</P>

C?H bond arylation of anilides inside copper-exchanged zeolites

Mathew, B.P.,Yang, H.J.,Jeon, H.,Lee, J.H.,Kim, J.C.,Shin, T.J.,Myung, K.,Kwak, S.K.,Kwak, J.H.,Hong, S.Y. Elsevier 2016 Journal of molecular catalysis Chemical Vol.417 No.-

<P>Syntheses of fine-chemicals using heterogeneous catalysts have tremendous industrial potentials, yet C-H functionalization studies have been largely focused on homogeneous catalysis. We report here the first meta-selective C-H bond arylation of anilides inside copper-exchanged zeolites. Mid- or large-pore zeolite frameworks are selected as supports to access large organic molecules, and atomically distributed copper catalysts exhibit high activities (84-90% conversions) toward direct arylation of anilides with diphenyliodonium salt on 0.5 mol% copper concentration. Computational studies indicate the well fitted copper-aryl complexes inside zeolite frameworks. Electron micrographs, elemental analyses, and reusability study show no observable leaching of catalytically active copper species during the reactions tested. These results demonstrate the practical synthetic potential of copper-exchanged zeolites as promising supported molecular catalysts to afford biaryl motifs-containing compounds with high catalytic activity, chemical stability, and recyclability. (C) 2016 Elsevier B.V. All rights reserved.</P>