625 research outputs found

    A comparative study of the performance of seven- and 63-chip optical code-division multiple-access encoders and decoders based on superstructured fiber Bragg gratings

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    We report a range of elementary optical coding and decoding experiments employing superstructured fiber Bragg grating (SSFBG) components: first, we perform a comparative study of the relative merits of bipolar and unipolar coding: decoding schemes and show that the SSFBG approach allows high-quality unipolar and bipolar coding. A performance close to that-theoretically predicted for seven-chip, 160-Gchip/s M-sequence codes is obtained. Second, we report the fabrication and performance of 63-chip, 160-Gchip/s, bipolar Gold sequence grating pairs. These codes are at least eight times longer than those generated by any other scheme based on fiber grating technology so far reported. Last, we describe a range of transmission system experiments for both the seven- and 63-bit bipolar grating pairs. Error-free performance is obtained over transmission distances of ~25 km of standard fiber. In addition, we have demonstrated error-free performance under multiuser operation (two simultaneous users). Our results highlight the precision and flexibility of our particular grating writing process and show that SSFBG technology represents a promising technology not just for optical code division multiple access (OCDMA) but also for an extended range of other pulse-shaping optical processing applications

    Designing Persuasive Avatars in mHealth for Arabic Culture: A Qualitative Study

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    Open innovation is built on the core principles of interactions, interdependence and exchange of knowledge. Clusters are believed to support organisations’ efforts to explore and source external knowledge, commercialise internal innovations and cause externalities through commercial activities. Early research on the innovation capabilities of regional clusters in Europe provides limited understandings of these cluster-based effects through which open innovation is fostered. This study investigates the role of clusters on open innovation practices relating to exploration and exploitation of external knowledge, knowledge sharing, acquisition and sale of IP rights of Indian IT organisations. The results reveal that organisations within a close geographic proximity actively participate in inbound and outbound activities and perform better in terms of innovation performance compared to the organisations outside the cluster. The findings are relevant to both the IT clusters and the IT innovation literature as this study sheds light on the role of clusters in improving an organisation’s innovation capabilities through open innovation

    Peroxidase extraction from jicama skin peels for phenol removal

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    Phenol and its derivatives exist in various types of industrial effluents, and are known to be harmful to aquatic lives even at low concentrations. Conventional treatment technologies for phenol removal are challenged with long retention time, high energy consumption and process cost. Enzymatic treatment has emerged as an alternative technology for phenol removal from wastewater. These enzymes interact with aromatic compounds including phenols in the presence of hydrogen peroxide, forming free radicals which polymerize spontaneously to produce insoluble phenolic polymers. This work aims to extract peroxidase from agricultural wastes materials and establish its application for phenol removal. Peroxidase was extracted from jicama skin peels under varying extraction conditions of pH, sample-to-buffer ratio (w/v %) and temperature. Experimental results showed that extraction process conducted at pH 10, 40% w/v and 25oC demonstrated a peroxidase activity of 0.79 U/mL. Elevated temperatures slightly enhanced the peroxidase activities. Jicama peroxidase extracted at optimum extraction conditions demonstrated a phenol removal efficiency of 87.5% at pH 7. Phenol removal efficiency was ∼ 97% in the range of 30 - 40oC, and H2O2 dosage has to be kept below 100 mM for maximum removal under phenol concentration tested

    Development and characterisation study of liposomes-encapsulated piroxicam

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    The objective of present work was to develop a novel liposomes-based drug delivery system for a lipophilic non-steroidal anti-inflammatory drug, piroxicam. The system was prepared using proliposomes method and optimised for different preparation parameters including type of proliposomes, concentration of drug, duration of hydration and type of particle size reduction treatment used. All prepared liposomal samples were extensively characterized for their drug-entrapment and size profile using various in-vitro techniques. Present work showed that the most optimum formulation (Pro-lipoTM Duo; 12mg piroxicam per gram Pro-lipoTM; 10 hours hydration time) produced highest amount of actual drug been entrapped in liposomes (800.4 mg/g Pro-lipoTM) with a satisfactory entrapment efficiency of 15.36%. This formulation had also produced liposomal samples with a homogenous (polydispersity index = 0.45) and small particle size (359.95nm). Extrusion technique was found to cause significant reduction in drug-entrapment and size profile of drug-loaded liposomes. A 4-weeks storage study showed that drug-entrapment and size profile of liposomal samples were stable in both refrigerated and room temperature. Electron microscopy revealed that prepared liposomal samples were spherical-shaped and showed concentric lamellae. In conclusion, present work successfully demonstrated a simple, reproducible and practical method of preparation for liposomes-encapsulated piroxicam.Keywords: Proliposomes; Liposomes; Piroxicam; Encapsulation; Particle size; Transmission electron microscop

    Neuroethics guiding principles for the NIH Brain Initiative

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    Neuroscience presents important neuroethical considerations. Human neuroscience demands focused application of the core research ethics guidelines set out in documents such as the Belmont Report. Various mechanisms, including institutional review boards (IRBs), privacy rules, and the Food and Drug Administration, regulate many aspects of neuroscience research and many articles, books, workshops, and conferences address neuroethics. (Farah, 2010; https://bioethicsarchive.georgetown.edu/pcsbi/studies.html; http://www.neuroethicssociety.org/annual-meeting). However, responsible neuroscience research requires continual dialogue among neuroscience researchers, ethicists, philosophers, lawyers, and other stakeholders to help assess its ethical, legal, and societal implications. The Neuroethics Working Group of the National Institutes of Health (NIH) Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative, a group of experts providing neuroethics input to the NIH BRAIN Initiative Multi-Council Working Group, seeks to promote this dialogue by proposing the following Neuroethics Guiding Principles (Table 1)

    Development and characterisation study of liposomes-encapsulated piroxicam.

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    The objective of present work was to develop a novel liposomes-based drug delivery system for a lipophilic non-steroidal anti-inflammatory drug, piroxicam. The system was prepared using proliposomes method and optimised for different preparation parameters including type of proliposomes, concentration of drug, duration of hydration and type of particle size reduction treatment used. All prepared liposomal samples were extensively characterized for their drug-entrapment and size profile using various in-vitro techniques. Present work showed that the most optimum formulation (Pro-lipoTM Duo; 12mg piroxicam per gram Pro-lipoTM; 10 hours hydration time) produced highest amount of actual drug been entrapped in liposomes (800.4 mg/g Pro-lipoTM) with a satisfactory entrapment efficiency of 15.36%. This formulation had also produced liposomal samples with a homogenous (polydispersity index = 0.45) and small particle size (359.95nm). Extrusion technique was found to cause significant reduction in drug-entrapment and size profile of drug-loaded liposomes. A 4-weeks storage study showed that drug-entrapment and size profile of liposomal samples were stable in both refrigerated and room temperature. Electron microscopy revealed that prepared liposomal samples were spherical-shaped and showed concentric lamellae. In conclusion, present work successfully demonstrated a simple, reproducible and practical method of preparation for liposomes-encapsulated piroxicam

    Experimental validation of a one-dimensional twin-entry radial turbine model under non-linear pulse conditions

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    This is the author¿s version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087419869157[EN] This article presents the experimental validation of a complete integrated one-dimensional twin-scroll turbine model able to be used in reciprocating internal combustion engine unsteady simulations. A passenger car with a twin-entry-type turbine has been tested under engine-like pulse conditions by means of a specifically built gas stand. To obtain high-resolution quality data, the turbine and turbine line pipes have been instrumented with mean and instantaneous pressure sensors as well as temperature and mass flow sensors, employing a uniquely designed rotating valve for the pulse generation. This experimental configuration enables to obtain the pressure decomposition in both inlets and outlets of the turbine. Using the experimental data obtained, the model is fully validated, with special focus on the reflected and transmitted components for analysing the performance of the model and its non-linear acoustics prediction capabilities. The model presents a very high degree of correlation with the experimental results, providing a range of errors similar to the uncertainty of the measurements, even in the medium- and high-frequency spectra.The author(s) disclosed receipt of the following financial support for the research, authorship and/or publication of this article: This work was supported by the 'Ayuda a Primeros Proyectos de Investigacion' (PAID-06-18), Vicerrectorado de Investigacion, Innovacion y Transferencia de la Universitat Politecnica de Valencia (UPV), Valencia, Spain. P.S. was partially supported through contract FPI-2017-S2-1428 of Programa de Apoyo para la Investigacion y Desarrollo (PAID) of Universitat Politecnica de Valencia.Serrano, J.; Arnau Martínez, FJ.; García-Cuevas González, LM.; Soler-Blanco, P.; Cheung, R. (2021). Experimental validation of a one-dimensional twin-entry radial turbine model under non-linear pulse conditions. 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A detailed one-dimensional model to predict the unsteady behavior of turbocharger turbines for internal combustion engine applications. International Journal of Engine Research, 20(3), 327-349. doi:10.1177/1468087417752525Galindo, J., Arnau, F. J., García-Cuevas, L. M., & Soler, P. (2018). Experimental validation of a quasi-two-dimensional radial turbine model. International Journal of Engine Research, 21(6), 915-926. doi:10.1177/1468087418788502Rajoo, S., Romagnoli, A., & Martinez-Botas, R. F. (2012). Unsteady performance analysis of a twin-entry variable geometry turbocharger turbine. Energy, 38(1), 176-189. doi:10.1016/j.energy.2011.12.017Rajoo, S., & Martinez-Botas, R. (2008). Variable Geometry Mixed Flow Turbine for Turbochargers: An Experimental Study. International Journal of Fluid Machinery and Systems, 1(1), 155-168. doi:10.5293/ijfms.2008.1.1.155Copeland, C. D., Martinez-Botas, R., & Seiler, M. (2010). Comparison Between Steady and Unsteady Double-Entry Turbine Performance Using the Quasi-Steady Assumption. Journal of Turbomachinery, 133(3). doi:10.1115/1.4000580Copeland, C. D., Martinez-Botas, R., & Seiler, M. (2011). Unsteady Performance of a Double Entry Turbocharger Turbine With a Comparison to Steady Flow Conditions. Journal of Turbomachinery, 134(2). doi:10.1115/1.4003171Costall, A. W., McDavid, R. M., Martinez-Botas, R. F., & Baines, N. C. (2010). Pulse Performance Modeling of a Twin Entry Turbocharger Turbine Under Full and Unequal Admission. Journal of Turbomachinery, 133(2). doi:10.1115/1.4000566Yang, M., Martinez-Botas, R., Rajoo, S., Yokoyama, T., & Ibaraki, S. (2015). An investigation of volute cross-sectional shape on turbocharger turbine under pulsating conditions in internal combustion engine. Energy Conversion and Management, 105, 167-177. doi:10.1016/j.enconman.2015.06.038Copeland, C. D., Newton, P. J., Martinez-Botas, R., & Seiler, M. (2011). The Effect of Unequal Admission on the Performance and Loss Generation in a Double-Entry Turbocharger Turbine. Journal of Turbomachinery, 134(2). doi:10.1115/1.4003226Cerdoun, M., & Ghenaiet, A. (2018). Unsteady behaviour of a twin entry radial turbine under engine like inlet flow conditions. Applied Thermal Engineering, 130, 93-111. doi:10.1016/j.applthermaleng.2017.11.001Payri, F., Benajes, J., & Reyes, M. (1996). Modelling of supercharger turbines in internal-combustion engines. International Journal of Mechanical Sciences, 38(8-9), 853-869. doi:10.1016/0020-7403(95)00105-0Chiong, M. S., Rajoo, S., Martinez-Botas, R. F., & Costall, A. W. (2012). Engine turbocharger performance prediction: One-dimensional modeling of a twin entry turbine. Energy Conversion and Management, 57, 68-78. doi:10.1016/j.enconman.2011.12.001Chiong, M. S., Rajoo, S., Romagnoli, A., Costall, A. W., & Martinez-Botas, R. F. (2016). One-dimensional pulse-flow modeling of a twin-scroll turbine. 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    Angiotensin-(1-7) prevents lipopolysaccharide-induced autophagy via the Mas receptor in skeletal muscle

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    Skeletal muscle atrophy, which occurs in lipopolysaccharide (LPS)-induced sepsis, causes a severe muscle function reduction. The increased autophagy contributes to sepsis-induced skeletal muscle atrophy in a model of LPS injection, increasing LC3II/LC3I ratio, autophagy flux, and autophagosomes. Angiotensin-(1-7) (Ang-(1-7)) has anti-atrophic effects via the Mas receptor in skeletal muscle. However, the impact of Ang-(1-7) on LPS-induced autophagy is unknown. In this study, we determined the effect of Ang-(1-7) on sepsis-induced muscle autophagy. C57BL6 wild-type (WT) mice and mice lacking the Mas receptor (KO Mas) were injected with LPS together with the systemic administration of Ang-(1-7) to determine autophagy in skeletal muscle. We also evaluated autophagy and p38 and c-Jun N-terminal kinase (JNK)activation. Our results show that Ang-(1-7) prevents LPS-induced autophagy in the diaphragm, tibialis anterior, and gastrocnemius of WT mice, which is demonstrated by a decrease in the LC3II/LC3I ratio and mRNA levels of lc3b and ctsl. This effect was lost in KO Mas mice, suggesting the role of the Mas receptor. The results in C2C12 cells show that Ang-(1-7) reduces several LPS-dependent effects, such as autophagy (LC3II/LC3I ratio, autophagic flux, and autophagosomes), activation of p38 and JNK, B-cell lymphoma-2 (BCL2) phosphorylation, and disassembly of the Beclin1/BCL2 complex. In conclusion, Ang-(1-7)/Mas receptor reduces LPS-induced autophagy in skeletal muscle. In vitro assays indicate that Ang-(1-7) prevents LPS-induced autophagy and modifies the MAPK signaling and the disassembly of a complex involved at the beginning of autophagy
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