3,303 research outputs found

    Evaluation of anticancer activity of Debregeasia Salicifolia extract against estrogen receptor positive cell line

    Get PDF
    Crude methanol extract and fractions of Debregeasia salicifolia stem were examined for their anticancer activity. To determine anticancer activity, different concentrations of crude extract were tested on MCF- 7 cancer cell line by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. D. salicifolia extract showed a significant antiproliferative activity and a dose dependent effect was observed. Minimum inhibition of 25.31% was shown by extract at concentration 10 ìg/ml and maximuminhibition (99%) was observed at 500 ìg/ml. Hexane, chloroform, ethyl acetate, methanol and aqueous fractions were also tested at a  concentration of 200 ìg/ml. Hexane, chloroform and ethyl acetatefractions appeared to be most active with 90 to 99% activity. These results indicate the possible potential use of D. salicifolia as antineoplastic agent. Preliminary phytochemical screening revealed the chemical composition of D. salicifolia extract containing flavonoids, anthraquinones and tannins.Anticancer properties of D. salicifolia can be linked with the presence of these chemicals.Key words: Anticancer, cytotoxic, Debregeasia salicifolia, MCF-7 cell line, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, phytochemical

    Fabrication of carbon thin films by pulsed laser deposition in different ambient environments

    Get PDF
    In this work, carbon thin films are grown in different background environments (Air, Helium and Argon) at different pressures (60, 160, 500 and 1000 mbar) by ablating the graphite target with Nd:YAG laser of wavelength of 1064 nm, pulse energy of 740 mJ and pulse rate of 6 ns. 10,000 laser shots are used to ablate graphite target under different ambient conditions. Grown thin films are analyzed by Atomic Force Microscopy (AFM) to measure thickness, roughness average, maximum profile peak height, average maximum height of profile and spacing ratio of the surface. The obtained results show that the roughness average, thickness of film, maximum profile peak height, average maximum height of profile and spacing ratio of thin films decreases with increase in ambient pressures and shows highest value at low pressure (160 mbar) in helium environment as compared with air and argon

    Local Ferromagnetism in Microporous Carbon with the Structural Regularity of Zeolite Y

    Full text link
    Magnetization M(H,T) measurements have been performed on microporous carbon (MC) with a three-dimensional nano-array structure corresponding to that of a zeolite Y supercage. The obtained results unambiguously demonstrate the occurrence of high-temperature ferromagnetism in MC, probably originating from a topological disorder associated with curved graphene sheets. The results provide evidence that the ferromagnetic behavior of MC is governed by isolated clusters in a broad temperature range, and suggest the occurrence of percolative-type transition with the temperature lowering. A comparative analysis of the results obtained on MC and related materials is given.Comment: To be published in Physical Review B (2003

    Electrochemical Insight into the Use of Microbial Fuel Cells for Bioelectricity Generation and Wastewater Treatment

    Get PDF
    Microbial fuel cell (MFC) technology is anticipated to be a practical alternative to the activated sludge technique for treating domestic and industrial effluents. The relevant literature mainly focuses on developing the systems and materials for maximum power output, whereas understanding the fundamental electrochemical characteristics is inadequate. This experimental study uses a double-chamber MFC having graphite electrodes and an anion-exchange membrane to investigate the electrochemical process limitations and the potential of bioelectricity generation and dairy effluent treatment. The results revealed an 81% reduction in the chemical oxygen demand (COD) in 10 days of cell operation, with an initial COD loading of 4520 mg/L. The third day recorded the highest open circuit voltage of 396 mV, and the maximum power density of 36.39 mW/m2 was achieved at a current density of 0.30 A/m2. The electrochemical impedance spectroscopy analysis disclosed that the activation polarization of the aerated cathode was the primary factor causing the cell’s resistance, followed by the ohmic and anodic activation overpotentials

    First order phase transition from ferromagnetism to antiferromagnetism in Ce(Fe0.96_{0.96}Al0.04_{0.04})2_2

    Full text link
    Taking the pseudobinary C15 Laves phase compound Ce(Fe0.96_{0.96}Al0.04_{0.04})2_2 as a paradigm for studying a ferromagnetic to antiferromagnetic phase transition, we present interesting thermomagnetic history effects in magnetotransport as well as magnetisation measurements across this phase transition. A comparison is made with history effects observed across the ferromagnetic to antiferromagnetic transition in R0.5_{0.5}Sr0.5_{0.5}MnO3_3 crystals.Comment: 11 pages of text and 4 figures; submitted to Physical Review Letter

    Development of a pulsar-based timescale

    Get PDF
    Using observations of pulsars from the Parkes Pulsar Timing Array (PPTA) project we develop the first pulsar-based timescale that has a precision comparable to the uncertainties in international atomic timescales. Our ensemble of pulsars provides an Ensemble Pulsar Scale (EPS) analogous to the free atomic timescale Echelle Atomique Libre (EAL). The EPS can be used to detect fluctuations in atomic timescales and therefore can lead to a new realisation of Terrestrial Time, TT(PPTA11). We successfully follow features known to affect the frequency of the International Atomic Timescale (TAI) and we find marginally significant differences between TT(PPTA11) and TT(BIPM11). We discuss the various phenomena that lead to a correlated signal in the pulsar timing residuals and therefore limit the stability of the pulsar timescale.Comment: Accepted for publication in MNRA

    Development and characterisation of novel electrospun polylactic acid/tubular clay nanocomposites

    Get PDF
    A novel material formulation method of polylactic acid /tubular clay nanocomposites via electrospinning was introduced and the important processing parameters such as solution concentration, clay loading, material feed rate were particularly investigated. The hybrid fibre diameter, the clay dispersability and the thermal properties of such nanocomposites were then characterised by using the scanning electron microscopy, wide-angle X-ray diffraction and differential scanning calorimetry, respectively, to establish a fundamental structure–property relationship for the future application

    Effects of Organoantimony(III) Compounds of Sterically Hindered Bifunctional Tetradentate Ligands on the Reproductive System of Male Rats

    Get PDF
    The antifertility activity of organoantimony(III) complexes PhSb[RC(NC6H4S)CH2(NC6H4S)CR′] {R' = CH3 (R1) and R = R' = CF3 (R2)} derived from corresponding sterically hinlered bifuinctional tetradentate ligands in the male rats was determined. The administration of compounds R1 and R2 at the dose level of 20 mg/kg. b. wt. siignificantly reduced the weights of testes and epididymides. Auxiliary glands showed a significant reduction after the treatment of compound R1 only. Treated animals showed a notable depression of spermatogenesis. The preleptotene spermatocytes were decreased by 76.19 and 47.06; the secondary spermatocytes by 87.4% and 54.87337; and the step-19 spermatids by 72.9 and 46.77% respectively, following the compound R1 and R2 treatment. Reduced sperm count and motility resulted in 100% negative fertility in both the treated groups. A significant fall in the content of various biochemical parameters of eproductive tissues was observed after R1 and R2 treatment in comparison to controls

    Магнитоэлектрические свойства мультиферроиков BiFeO3 замещенных цинком

    Get PDF
    Проведены исследования магнитоэлектрических свойств керамических образцов мультиферроиков BiFe1−xZnxO3 и Bi1−xZnxFe1−xZnxO3 в области магнитных полей от 0 до 80kOe при комнатной температуре. Все образцы имеют линейные зависимости магнитоэлектрического коэффициента αME с малыми горбообраз- ными максимумами αME как при 10, так и при 85 kHz. Проведенные магнитоэлектрические исследования в образцах серий феррита висмута с двойным замещенным Zn показывает, что двойное замещение ионов Bi3+ и Fe3+ ионами Zn2+ не дают желаемого усиления магнитоэлектрических свойств по сравнению с ординарным замещением Zn2+

    Intrusion Detection in Industrial Networks via Data Streaming

    Get PDF
    Given the increasing threat surface of industrial networks due to distributed, Internet-of-Things (IoT) based system architectures, detecting intrusions in\ua0 Industrial IoT (IIoT) systems is all the more important, due to the safety implications of potential threats. The continuously generated data in such systems form both a challenge but also a possibility: data volumes/rates are high and require processing and communication capacity but they contain information useful for system operation and for detection of unwanted situations.In this chapter we explain that\ua0 stream processing (a.k.a. data streaming) is an emerging useful approach both for general applications and for intrusion detection in particular, especially since it can enable data analysis to be carried out in the continuum of edge-fog-cloud distributed architectures of industrial networks, thus reducing communication latency and gradually filtering and aggregating data volumes. We argue that usefulness stems also due to\ua0 facilitating provisioning of agile responses, i.e. due to potentially smaller latency for intrusion detection and hence also improved possibilities for intrusion mitigation. In the chapter we outline architectural features of IIoT networks, potential threats and examples of state-of-the art intrusion detection methodologies. Moreover, we give an overview of how leveraging distributed and parallel execution of streaming applications in industrial setups can influence the possibilities of protecting these systems. In these contexts, we give examples using electricity networks (a.k.a. Smart Grid systems).We conclude that future industrial networks, especially their Intrusion Detection Systems (IDSs), should take advantage of data streaming concept by decoupling semantics from the deployment
    corecore