699 research outputs found

    Investigation of furo[2,3-h]- and pyridazino[3,4-f]cinnolin-3-ol scaffolds as substrates for the development of novel HIV-1 integrase inhibitors

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    With the aim to develop novel HIV-1 integrase inhibitors, we obtained a set of condensed ring systems based on the furo[2,3-h]cinnolin-3(2H)-one and pyridazino[3,4-f]cinnolin-3-ol scaffolds bearing a potential chelating pharmacophore, which can be involved in the inhibition mechanism of the enzyme. Herein, we report the design, synthesis, structural investigation and preliminary biological results of these heteroaromatic systems

    Analysing Critical Factors of Strategic Alignment Between Operational Excellence and Industry 4.0 Technologies in Smart Manufacturing

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    The manufacturing sector is highly competitive and operationally complex. Therefore, the strategic alignment between operational excellence methodologies and Industry 4.0 technologies is one of the issues that need to be addressed. The main aim of the study is to determine the critical factors of strategic alignment between operational excellence methodologies and Industry 4.0 technologies for manufacturing industries and make comparative analyses between automotive, food, and textile industries in terms of strategic alignment between operational excellence methodologies and Industry 4.0 technologies. Firstly, determining the critical factors based on literature review and expert opinions, these criteria are weighted, and Analytical Hierarchy Process is run to calculate the weights of these criteria. Afterwards, the best sector is determined by the Gray Relational Analysis method according to the criteria for the three manufacturing industries selected for the study. As a result of AHP, ‘Infrastructure for Right Methodology, Techniques and Tools, is in the first place, ‘Organizational Strategy, is in the second place, while the third highest critical factor is ‘Capital Investment’. Moreover, based on Gray Relational Analysis results, the automotive industry is determined as the best alternative in terms of strategic alignment between OPEX methodologies and I4.0 technologies. This study is unique in that it is primarily possible to obtain the order of importance within the criteria and to make comparisons between three important manufacturing industries that are important for the economies of the world

    Imaging Coulomb Islands in a Quantum Hall Interferometer

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    In the Quantum Hall regime, near integer filling factors, electrons should only be transmitted through spatially-separated edge states. However, in mesoscopic systems, electronic transmission turns out to be more complex, giving rise to a large spectrum of magnetoresistance oscillations. To explain these observations, recent models put forward that, as edge states come close to each other, electrons can hop between counterpropagating edge channels, or tunnel through Coulomb islands. Here, we use scanning gate microscopy to demonstrate the presence of quantum Hall Coulomb islands, and reveal the spatial structure of transport inside a quantum Hall interferometer. Electron islands locations are found by modulating the tunneling between edge states and confined electron orbits. Tuning the magnetic field, we unveil a continuous evolution of active electron islands. This allows to decrypt the complexity of high magnetic field magnetoresistance oscillations, and opens the way to further local scale manipulations of quantum Hall localized states

    Metal sorption by biochars : a trade-off between phosphate and carbonate concentration as governed by pyrolysis conditions

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    Three feedstocks, pine wood, grass and cow manure, were pyrolyzed under various conditions and tested on their ability to sorb metals in aquatic systems. The feedstocks were pyrolyzed at 2 different temperatures (350 degrees C and 550 degrees C) and 2 different residence times (10 and 60 min) and resulting biochars were assessed on their capability to immobilize Pb, Cu, Cd and Zn. Manure-based chars, and to a lesser extent grass-based chars, featured high concentrations of phosphates and carbonates, These anions play an important role in metal sorption because they form insoluble complexes with the metals. Washing reduced the concentration of these anions, leading to a reduced sorption of metals by the biochar. The carbonate concentration on the biochars' surface increased at higher reactor temperature and longer residence times. The opposite trend was observed for the phosphate concentration and the cation exchange capacity. Accordingly, the optimal temperature-residence time combination for sorption was a trade-off between these properties. Biochar produced from cow manure and pyrolyzed at 550 degrees C for 10 min showed the best sorption for all metals considered

    Assessing the Impact of COVID-19 on Sustainable Food Supply Chains

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    Recently, it has become an important issue to ensure sustainability, especially in food supply chains, against the rapidly growing population, increasing demand, and sudden disruptions caused by uncertain times such as that caused by COVID-19. Since food supply chains has vulnerable products and processes, it is critical to understand the sustainability factors of food supply chains especially in uncertain times such during the COVID-19 pandemic. This study aims to determine sustainability factors of food supply chains. An Interpretive Structural Modelling method is used to state the relations between sustainability factors of food supply chains. As a result of the study, Information Sharing and Managerial Approaches are classified as driving factors; Food Safety and Security, Know-How Transfer, Logistics Networking, Risk Mitigation, Employee Commitment, Innovation, Traceability and Responsiveness are categorized as linkage factors. This article will be beneficial for managers in helping them develop sustainable food supply chains during uncertain times by focusing on traceability, information sharing, know-how transfer, food safety and security

    Dissipation effects in spin-Hall transport of electrons and holes

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    We investigate the spin-Hall effect of both electrons and holes in semiconductors using the Kubo formula in the correct zero-frequency limit taking into account the finite momentum relaxation time of carriers in real semiconductors. This approach allows to analyze the range of validity of recent theoretical findings. In particular, the spin-Hall conductivity vanishes for vanishing spin-orbit coupling if the correct zero-frequency limit is performed.Comment: 5 pages, no figures, version to appear in Phys. Rev.

    PHARMACOGNOSTIC EVALUATION OF GOMPHRENA SERRATA ROOT

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    Objectives: Gomphrena serrata (Amaranthaceae) has been utilized for many ailments in the conventional system ethnomedicinally; most significantly against bronchial asthma, diarrhea, hay fever, pains, tonic, carminative, diabetes, dermatitis, and piles. The key challenge experienced in the standardization of herbal drugs is the correct identification of the plant source. Thus, setting up quality control parameters by means of pharmacognostic and phytochemical analysis which assures the purity, safety, and efficiency of G. serrata is necessary. The current research was conducted to assess the pharmacognostic characteristics including macroscopic, microscopic, phytochemical and physicochemical parameters of the root of G. serrata. Methods:  Micro, as well as macroscopic characteristics was investigated. Physicochemical parameters had been done by implementing WHO suggested parameters; preliminary phytochemical and fluorescent evaluation of root was executed for appropriate identification and standardization. Results:  The color, shape, size, odor, and surface characteristics were reported from the root and powdered root material of G. serrata.  Light microscope images of cross section and powdered root revealed the presence of lignified xylem fibers, xylem vessels, cork cells and parenchyma cells. Phytochemical testing confirmed the presence of alkaloids, carbohydrates, saponins, tannins, proteins, amino acids, phytosterols and flavonoids. Physicochemical parameters such as moisture content, ash value, extractive value and fluorescent behavior of root powder have also been established Conclusion: The current research is useful in order to supplement the information with regard to its standardization, identification and in carrying out further investigation in Ayurvedic system of medicine.            Peer Review History: Received 24 July 2017;   Revised 22 August; Accepted 28 August, Available online 15 September 2017 Academic Editor: Dr. Asia Selman Abdullah, Al-Razi university, Department of Pharmacy, Yemen, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:        Reviewer's Comments: Average Peer review marks at initial stage: 4.0/10 Average Peer review marks at publication stage: 7.5/10 Reviewer(s) detail: Dr. Marwa A. A. Fayed, University of Sadat City, Egypt, [email protected] Dr. Mohamed Said Fathy Al-Refaey, University of Sadat City, Menofia, Egypt, [email protected] Similar Articles: PURIFICATION AND BIOLOGICAL ACTIVITIES OF COMBINATION OF HEMI-SYNTHESIZED THIOSEMICARBAZONES OF MITRACARPUS SCABER ZUC

    A review of selected topics in physics based modeling for tunnel field-effect transistors

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    The research field on tunnel-FETs (TFETs) has been rapidly developing in the last ten years, driven by the quest for a new electronic switch operating at a supply voltage well below 1 V and thus delivering substantial improvements in the energy efficiency of integrated circuits. This paper reviews several aspects related to physics based modeling in TFETs, and shows how the description of these transistors implies a remarkable innovation and poses new challenges compared to conventional MOSFETs. A hierarchy of numerical models exist for TFETs covering a wide range of predictive capabilities and computational complexities. We start by reviewing seminal contributions on direct and indirect band-to-band tunneling (BTBT) modeling in semiconductors, from which most TCAD models have been actually derived. Then we move to the features and limitations of TCAD models themselves and to the discussion of what we define non-self-consistent quantum models, where BTBT is computed with rigorous quantum-mechanical models starting from frozen potential profiles and closed-boundary Schr\uf6dinger equation problems. We will then address models that solve the open-boundary Schr\uf6dinger equation problem, based either on the non-equilibrium Green's function NEGF or on the quantum-transmitting-boundary formalism, and show how the computational burden of these models may vary in a wide range depending on the Hamiltonian employed in the calculations. A specific section is devoted to TFETs based on 2D crystals and van der Waals hetero-structures. The main goal of this paper is to provide the reader with an introduction to the most important physics based models for TFETs, and with a possible guidance to the wide and rapidly developing literature in this exciting research field

    Sex Determination in the Squalius alburnoides Complex: An Initial Characterization of Sex Cascade Elements in the Context of a Hybrid Polyploid Genome

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    BACKGROUND:Sex determination processes vary widely among different vertebrate taxa, but no group offers as much diversity for the study of the evolution of sex determination as teleost fish. However, the knowledge about sex determination gene cascades is scarce in this species-rich group and further difficulties arise when considering hybrid fish taxa, in which mechanisms exhibited by parental species are often disrupted. Even though hybridisation is frequent among teleosts, gene based approaches on sex determination have seldom been conducted in hybrid fish. The hybrid polyploid complex of Squalius alburnoides was used as a model to address this question. METHODOLOGY/PRINCIPAL FINDINGS:We have initiated the isolation and characterization of regulatory elements (dmrt1, wt1, dax1 and figla) potentially involved in sex determination in S. alburnoides and in the parental species S. pyrenaicus and analysed their expression patterns by in situ hybridisation. In adults, an overall conservation in the cellular localization of the gene transcripts was observed between the hybrids and parental species. Some novel features emerged, such as dmrt1 expression in adult ovaries, and the non-dimorphic expression of figla, an ovarian marker in other species, in gonads of both sexes in S. alburnoides and S. pyrenaicus. The potential contribution of each gene to the sex determination process was assessed based on the timing and location of expression. Dmrt1 and wt1 transcripts were found at early stages of male development in S. alburnoides and are most likely implicated in the process of gonad development. CONCLUSIONS/SIGNIFICANCE:For the first time in the study of this hybrid complex, it was possible to directly compare the gene expression patterns between the bisexual parental species and the various hybrid forms, for an extended set of genes. The contribution of these genes to gonad integrity maintenance and functionality is apparently unaltered in the hybrids, suggesting that no abrupt shifts in gene expression occurred as a result of hybridisation
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