4,404 research outputs found
A User-Centred Approach Exploring the Potential of a Novel EMG Switch for Control of Assistive Technology
This study examines the potential application of an EMG technology as an assistive control method for individuals with severe physical disabilities. The usability and acceptability of a prototype EMG switch was evaluated with health care professionals, researchers and end users using participatory approaches
Surfactant-aided impregnation of MnF2 into CNT fabrics as cathode material with high electrochemical performance for lithium ion batteries
© 2018 Elsevier Ltd MnF2 infiltrated-CNT fabrics was prepared by surfactant-aided impregnation of MnSiF6 precursors in acid-treated CNT fabric followed by annealing MnSiF6-loaded CNT fabric. The structural and morphological characterizations by X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) confirmed the formation of MnF2 nanoparticles (average size: 20–30 nm) within CNT fabric structure. Galvanostatic charge-discharge tests of CNT-MnF2 nanocomposite fabrics showed excellent electrochemical performance and good cycle stability between 0.4 and 4.0 V vs Li/Li+. A specific capacity of 388 mAh/g was measured at 0.1C for CNT-MnF2 fabric with 70% MnF2 loading after 100 cycles. Stable cyclability and good rate performance were obtained at high charge-discharge cycling rates. MnF2 loading largely affect the performance of MnF2 infiltrated-CNT fabrics cathodes when lower than 70% MnF2 loaded-CNT fabrics were prepared. It can be concluded that nano-sized active materials infiltrated inside conductive carbon matrix in optimized content can lead to rapid kinetics and stable performance for flexible metal fluoride-based cathode materials.This work was funded by a grant from the Qatar National Research Fund under its National Priorities Research Program award number NPRP7-567-2-216 . Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Qatar National Research Fund . The authors are thankful to Prof Gleb Yushin from Georgia Institute of Technology for his collaboration in this subject
Serological, hematological, Biochemical and Oxidative Markers During Foot and Mouth Disease Serotype ‘O’ Infection, Egypt
Foot and mouth disease (FMD) is an extremely grave communicable disease of livestock. It affects all wild and domestic animals with cloven hoof. It is caused by Aphtho virus (Apthous fever) or (FMDV) foot and mouth disease virus which is originated from family Picornaviridae. 30 adult female water buffaloes, 3-5 years old infected with FMD serotypes, O. These animals were located at Sharkia governorate, Egypt during the period beetwen December 2014 to March 2015. Hematological findings showed no significant change in erythrogram and reduction in total leukocytes in the early stage of FMDV infection. Moreover development of macrocytic normochromic anemia and increase in total leukocytes and lymphocytic counts was reported in the late stage of infection. A significant decrease in cholesterol , progesterone , total proteins, albumin , globulins, calcium and sodium levels in infected groups, while a significant increase in serum activities of ALT ,AST, glucose, total, direct ,indirect bilirubine, phosphorous potassium, NO. MDA, CK-MB, LDH and CTNI. Without alterations in creatinine level
Isolation and characterization of antineoplastic alkaloids from Catharanthus roseus l. Don. cultivated in Egypt
Vinblastine and vincristine (the antileukemic agents) were isolated, in a pure form, from Catharanthus roseus L. Don., cultivated in Egypt, by several chromatographic techniques. Five modified methods for the preparation of total alkaloids were carried out. All the isolated mixtures were evaluated by HPLC and HPTLC analyses. The antineoplastic alkaloids; vinblastine and vincristine, were isolated by the use of vacuum liquid chromatographic column on silica gel : aluminium oxide (1:1) mixed bed vacuum liquid chromatography (VLC), Charcoal column, and finally purified by centrifugally accelerated radial chromatography (Chromatotrone).Key words: Catharanthus roseus L., Apocyanaceae, Vinblastine, Vincrisitine, Antileuckemic alkaloids, VLC, HPLC, HPTL
MICROWAVE-ASSISTED EXTRACTION OF BIO-ACTIVE COMPOUNDS (PHENOLICS AND ALKAMIDES) FROM ECHINACEA PURPUREA
Objective: Echinacea purpurea is used widely for its unspecific enhancement of the immune system. It contains multiple bioactive substances, including, phenolics (caffeic acid derivatives), flavonoids, anthocyanins and alkamides. In this currently investigation, efforts are focused on the evaluation of extraction techniques viz., conventional extraction (CE) and microwave-assisted extraction (MAE) for the regeneration of the active constituents of Echinacea purpurea.
Methods: The aerial parts have been separately extracted with 80% methanol by two methods; CE and MAE. Identification of the isolated compounds was carried out by spectroscopic analysis viz., UV, TLC, 1H- NMR and MS. TLC scanner system and RP-HPLC with UV detection have been employed for the quantitative determination of caffeic acid derivatives and that of alkamides content in both extracts.
Results: Chicoric and caftaric acids have been isolated and identified. The results of the TLC scanner system have revealed that the concentration is about 1.19 ± 0.02 and 1.35 ± 0.03 % (w/w) for caftaric and chicoric acid, respectively of the dry plant material extracted with CE, while the concentration is 1.81 ± 0.04 and 6.19 ± 0.26 % (w/w) for the two acids, respectively of the dry plant material extracted by MAE. The results of the HPLC have revealed that the concentration of alkamides is 0.25 and 0.33 % (w/w) of the dry plant material obtained with CE and MAE, respectively.
Conclusion: Our study proved that MAE is a more effective technique compared to the CE. Extraction time was reduced, with the use of less solvent and the yield amount of the extracted active compounds was increased
Heat and freezing pre-thermal treatments as a means of freeing potatoes from mosaic virus and its effects on potato plants quality characters
The aim of the study was to control of potato mosaic virus by using hot-air, hot-water and freezing as a physical pre-thermal treatments. Infected tubers of Lady Rosetta and Mondial potato (Solanum tuberosum L.) cultivars were treated by hot-air and hot-water treatments at 55± 2 ̊ C and freezing treatment at -18±2 ̊ C for 1, 2, 3 and 4 hours. Hot-air and freezing treatments showed complete elimination of mosaic virus from treated tubers. Hot-water treatment caused tuber damage at different exposure times. In this respect, hot-air treatment at 55± 2 ̊ C and freezing treatment at -18±2 ̊ C for two hours gave the best results of eliminating the virus from tubers and did not affect on economic characters of potato cultivars.
A Scanning Electron Microscopic Study of the Chick Chorioallantoic Membrane: Cell Death and the Involvement of Oxygen Free Radicals
Cell death is a normal feature within the chick chorioallantoic membrane, occurring principally between days 10 and 14 of incubation.
Samples of chorioallantoic membrane were obtained on days 6, 8, 10, 12 and 14 of incubation, after the creation of artificial air chambers on day 3. These were examined by scanning electron microscopy (SEM), transmission electron microscopy (TEM) after staining for acid phosphatase activity, and by light microscopy after demonstrating oxygen free radicals with nitro blue tetrazolium. On day 6, small defects in the plasmalemma, approximately 200 nm in diameter, could be seen by SEM. A sequence of events leading to complete destruction of the plasmalemma, with exposure of the nucleus and other cytoplasmic organelles, could be traced, and by day 8 the membrane was a mosaic of healthy cells and others in various stages of degeneration.
TEM revealed that acid phosphatase activity was confined to the golgi apparatus and associated vesicles even in advanced stages of degeneration. By comparison, oxygen free radicals were demonstrated in individual cells from day 6 onwards. Application of superoxide dismutase and catalase to the epithelium using a nebuliser spray significantly reduced the amount of cell death seen by scanning microscopy on day 12. It is concluded that oxygen free radicals may mediate cell death in the chorioallantoic membrane
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