Comprehensive thermal and structural characterization of antimony-phosphate glass

For the first time, we prepare new ternary glass systems of composition (95-x)Sb2O3-xP2O5-5MgO, where x = 45, 40, 35 mol%; (85-x)Sb2O3-xP2O5-15MgO, where x = 55, 35, 25 mol%; (75-x)Sb2O3-xP2O5-25MgO, where x = 45, 35, 25 mol%; and 60Sb2O3-(40-x)P2O5-xMgO, where x = 10, 20 mol% via melt-quenching method. Synthesized glasses are characterized using XRD, FESEM, EDX, and TG/DTA measurements. The influence of varying modifier concentrations on their thermal properties is evaluated. The XRD patterns confirmed the amorphous nature of samples. SEM images demonstrated interesting phase formation with ribbons-like texture. Five crystalline phases are evidenced in the ternary diagram which are antimony phosphate and antimony orthophosphate as major phases as well as magnesium phosphate, magnesium cyclo-tetraphosphate and cervantite as minor phases. EDX spectra detected the right elemental traces. Detailed thermal analysis of these glasses revealed their high-molecular polymer character for Sb2O3 content greater than 50 mol%. Three different glass transition temperatures are achieved around 276, 380–381 and 422–470 °C depending on the composition. Furthermore, the solidus and liquidus temperature are found to decrease with increasing Sb2O3 and increases for MgO contents till 15 mol% and then decrease, where the lowest recorded solidus temperature is 426 °C. This observation may open up new research avenues for antimony based ternary glasses and an exploitation of the derived results for optoelectronics applications, photonic devices and non-linear optical devices

Integration of Mechatronics Design Approach into Teaching of Modeling Practices

Engineering design has transformed significantly due to advances in embedded system design and computer technologies. Almost every mechanical design today has some electrical and electronic components. Many products manufactured today contain both electrical and mechanical components and systems. Mechatronics is a design process that is multi-disciplinary in nature and integrates principles of many engineering disciplines including, but not limited to, mechanical engineering and mechanical engineering technology, electrical engineering and electrical engineering technology, and controls engineering. Mechatronic systems can be found in many different places today. These range from computer hard drives and robotic assembly systems, to washing machines, coffee makers, printers, and medical devices, as well as to various advanced manufacturing machines and devices that are numerically controlled, such as additive manufacturing machines, rapid prototyping machines and multi-axis CNC machines. The main purpose for integrating a mechatronics themed activity into a computer-modeling course is to engage students in project-based learning through hands-on activities related to modeling a mechatronic device. Students learn the basics of electromechanical systems, the integration of machine elements (gear reducer) and the basics of actuators (electrical motor), all of which are fundamental to understanding mechatronic systems through activities related to the mechatronic design principles. Hence, engineering design for mechanical engineers and mechanical engineering technologists have to involve embedded multi-disciplinary knowledge with the understanding of both mechanical and electrical systems. This paper will focus on presenting the use of modeling as a vehicle to teaching more complex engineering concepts, such as gears, linkage analysis, animation and the solid modelling course content

Implementing Mechatronics Design Methodology in Mechanical Engineering Technology Senior Design Projects at the Old Dominion University

In recent years, the nature of engineering design has changed due to advances in embedded system design and computer technologies. It is rare to engineer a purely mechanical design that does not incorporate electrical and electronic components. Mechanical engineers and mechanical engineering technologists must possess a multi-disciplinary knowledge with the understanding of both mechanical and electrical systems. For this purpose, undergraduate programs in engineering technology have added mechatronics courses to their curriculum. Mechatronics is a design process that is multi-disciplinary in nature and integrates principles of many engineering disciplines including, but not limited to, mechanical engineering, electrical engineering, and controls engineering. These courses typically incorporate problem-based learning and project-based pedagogy to effectively build the student’s knowledge and understanding. Old Dominion University’s Mechanical Engineering Technology (ODU MET) program offers undergraduate courses related to Advanced Manufacturing including Robotics; Automation; Lean Manufacturing; Computer Integrated Manufacturing; and Advanced Manufacturing Processes. Recently, two new courses related to mechatronics were added to the same focus area. In addition, ODU MET program has placed an increased emphasis on mechatronics for students’ senior design projects. This paper highlights the benefits of including mechatronics in the ODU MET curriculum and presents several recent senior design projects that showcase how the student has incorporated multi-disciplinary principles into the design and build of a functional mechatronic device. By embedding these experience into their senior design project, students are exposed to other engineering technology areas, learn the terminology of other professions, and feel more confident to join the workforce with the cross-disciplinary skills needed to be successful

Changes in structural network topology correlate with severity of hallucinatory behavior in Parkinson's disease

Inefficient integration between bottom-up visual input and higher order visual processing regions is implicated in visual hallucinations in Parkinson's disease (PD). Here, we investigated white matter contributions to this perceptual imbalance hypothesis. Twenty-nine PD patients were assessed for hallucinatory behavior. Hallucination severity was correlated to connectivity strength of the network using the network-based statistic approach. The results showed that hallucination severity was associated with reduced connectivity within a subnetwork that included the majority of the diverse club. This network showed overall greater between-module scores compared with nodes not associated with hallucination severity. Reduced between-module connectivity in the lateral occipital cortex, insula, and pars orbitalis and decreased within-module connectivity in the prefrontal, somatosensory, and primary visual cortices were associated with hallucination severity. Conversely, hallucination severity was associated with increased between- and within-module connectivity in the orbitofrontal and temporal cortex, as well as regions comprising the dorsal attentional and default mode network. These results suggest that hallucination severity is associated with marked alterations in structural network topology with changes in participation along the perceptual hierarchy. This may result in the inefficient transfer of information that gives rise to hallucinations in PD. Author SummaryInefficient integration of information between external stimuli and internal perceptual predictions may lead to misperceptions or visual hallucinations in Parkinson's disease (PD). In this study, we show that hallucinatory behavior in PD patients is associated with marked alterations in structural network topology. Severity of hallucinatory behavior was associated with decreased connectivity in a large subnetwork that included the majority of the diverse club, nodes with a high number of between-module connections. Furthermore, changes in between-module connectivity were found across brain regions involved in visual processing, top-down prediction centers, and endogenous attention, including the occipital, orbitofrontal, and posterior cingulate cortex. Together, these findings suggest that impaired integration across different sides across different perceptual processing regions may result in inefficient transfer of information

A network approach for managing and processing big cancer data in clouds

Translational cancer research requires integrative analysis of multiple levels of big cancer data to identify and treat cancer. In order to address the issues that data is decentralised, growing and continually being updated, and the content living or archiving on different information sources partially overlaps creating redundancies as well as contradictions and inconsistencies, we develop a data network model and technology for constructing and managing big cancer data. To support our data network approach for data process and analysis, we employ a semantic content network approach and adopt the CELAR cloud platform. The prototype implementation shows that the CELAR cloud can satisfy the on-demanding needs of various data resources for management and process of big cancer data

Polyisobutylene-paclitaxel conjugates with pendant carboxylic acids and polystyrene chains: Towards multifunctional stent coatings with slow drug release

Drug-eluting stents are used in the treatment of atherosclerosis, where the incorporation of anti-proliferative or anti-inflammatory drugs decreases the rate of restenosis, the recurrence of artery narrowing. However, these stents can suffer from limitations such as drug depletion and delamination of the drug-eluting coating from the stent surface. Described here is an approach aimed at addressing these issues. Starting from a maleic anhydride adduct of polyisobutylene (PIB) prepared from butyl rubber, ring opening using paclitaxel (PTX) or a combination of PTX and polystyrene (PS) afforded covalent conjugates of PTX and PIB or PIB-PS graft copolymers bearing pendant carboxylic acids. When coated on stainless steel, the drug release was slower than that from a control coating that ressembles a clinical formulation comprising a physical mixture of a PS-PIB-PS triblock copolymer (SIBS) and PTX. The PTX conjugates also exhibited enhanced adhesion to stainless steel and increased tensile strength in comparison with the starting rubber. Cytotoxicity assays indicated that the materials did not leach toxic levels of PTX into cell culture media. Nevertheless, they were capable of inhibiting the adhesion and proliferation of C2C12 cells on their surfaces. These properties are advantageous for the potential application of the materials as stent coatings

Discovery of a Histidine‐Based Scaffold as an Inhibitor of Gut Microbial Choline Trimethylamine‐Lyase

This is the peer reviewed version of the following article: Discovery of a Histidine‐Based Scaffold as an Inhibitor of Gut Microbial Choline Trimethylamine‐Lyase, which has been published in final form at https://doi.org/10.1002/cmdc.202000571. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions.Anaerobic choline metabolism by human gut microbiota to produce trimethylamine (TMA) has recently evolved as a potential therapeutic target because of its association with chronic kidney disease and increased cardiovascular risks. Limited examples of choline analogues have been reported as inhibitors of bacterial enzyme choline TMA‐lyase (CutC), a key enzyme regulating choline anaerobic metabolism. We used a new workflow to discover CutC inhibitors based on focused screening of a diversified library of small molecules for intestinal metabolic stability followed by in vitro CutC inhibitory assay. This workflow identified a histidine‐based scaffold as a CutC inhibitor with an IC50 value of 1.9±0.2 μM. Remarkably, the identified CutC inhibitor was able to reduce the production of TMA in whole‐cell assays using various bacterial strains as well as in complex gut microbiota environment. The improved efficiency of the new scaffold identified in this study in comparison to previously reported CutC inhibitors would enable optimization of potential leads for in vivo screening and clinical translation. Finally, docking studies and molecular‐dynamic simulations were used to predict putative interactions created between inhibitor and CutC

EGFR tyrosine kinase targeted compounds

In this study, we illustrate computer aided drug design of new benzothiazole and pyrimido[2,1-b]benzothiazole derivatives as epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors. Compounds 1-5 were screened at NCI, USA, for antitumor activity against non-small cell lung cancer (NCI-H522), colon cancer (HCT-116, HCT-15 and HT29) and breast cancer (MDA-MB-468 and MDA-MB-231/ATCC) cell lines in which EGFR is overexpressed in varying levels. Results indicated that these compounds are more potent antitumor agents compared to erlotinib against HT29 and MDA-MB-231/ATCC cell lines. Compound 3 showed GI50 value of 22.3 nM against NCI-H522 cell line, while erlotinib exhibited GI50 value of 1 μM against the same cell line. In addition, these compounds were studied for their EGFR tyrosine kinase inhibitory activity. Virtual screening utilizing molecular modeling and QSAR techniques enabled the understanding of the pharmacophoric requirements for antitumor activity. Docking the designed compounds into the ATP binding site of EGFR-TK domain was done to predict the analogous binding mode of these compounds to the EGFR-TK inhibitors

Efficacite technique des producteurs de mais participant au warrantage dans le nord-est du Benin

Face au bradage massif des productions agroalimentaires en période de récolte, le warrantage a été promu pour faciliter l’accès des producteurs au crédit agricole, aux marchés des facteurs de production et de produits agricoles afin d’améliorer leur efficacité technique et leurs revenus agricoles. La présente étude vise à mesurer le niveau d’efficacité technique des producteurs de maïs participants et non participants au warrantage dans une région du Bénin et à déterminer les facteurs qui influencent cette efficacité. L'approche d'estimation en une seule étape de la frontière stochastique de production et du modèle qui détermine les facteurs d'inefficacité technique a été appliquée à un échantillon aléatoire stratifié de 314 producteurs de maïs dont 157 producteurs participants au warrantage. Les résultats ont montré que les producteurs n’opèrent pas tous sur la frontière de production. Le niveau moyen d’efficacité technique a été de 74 % avec 78 % pour les bénéficiaires et 70 % pour les non bénéficiaires. Le niveau actuel moyen de leur production annuelle qui est de 16 014 kg pourrait être encore amélioré de 33 % avec les mêmes ressources productives. L’accès au warrantage, le sexe, l’utilisation de la semence améliorée de maïs, l’appartenance à un groupement de producteurs hors warrantage et la possession d’un moyen d’information sont les facteurs qui influencent positivement l’efficacité technique des producteurs. Ainsi, il est important que l’évaluation de l’impact du warrantage soit réalisée afin d’améliorer sa promotion. English title: TECHNICAL EFFICIENCY OF MAIZE PRODUCERS PARTICIPATING IN WARRANTAGE IN THE NORTHEASTERN OF BENIN Abstract Faced with the massive sell-off of agri-food production during the harvest period, warrantage was promoted to facilitate producers’ access to agricultural credit, production factors and agricultural products markets in order to improve their technical efficiency and farm income. This study aims to measure the level of technical efficiency of maize producers participating and not participating in warrantage in a region of Benin and to determine the factors that influence this efficiency. A one stage stochastic frontier production which incorporates a model for the technical ineffiency effects was applied to a stratified random sample of 314 maize producers, including 157 producers participating in warrantage. The results showed that the producers do not operate on the production frontier. The average level of technical efficiency is 74% with 78% for beneficiaries and 70% for non-beneficiaries. The current average level of their annual production, which is 16,014 kg, could be further improved by 33% with the same productive resources. Access to warrantage, gender, use of improved maize seed, membership in a non-warrantage producers’ group and possession of a means of information are the factors that positively influence the technical efficiency of producers. Thus, it is important that the impact of warrantage be evaluated in order to improve its promotion. Maize; technical efficiency; warrantage; stochastic production frontier; Beni