686 research outputs found

    PHYTOCHEMICAL STUDY AND THE ANTIPROLIFERATIVE ACTIVITY OF INULA VULGARIS SPECIES GROWN IN LEBANON

    Get PDF
    Objective: Cancer represents the second leading cause of death after stroke and heart diseases. Plant extracts have long been used in traditional medicine for the prevention and treatment of many illnesses, including some types of cancer. The aim of this study was to evaluate the antiproliferative effects of ethyl acetate fractions of two Lebanese herbs: Inula viscosa (I. vis) and Inula vulgaris (I. vul).Methods: Plants were extracted with ethanol followed by ethyl acetate, then dried and tested on three cell lines including CaCO2, HepG2, and MCF7, to check for their viability and antiproliferative activity, using trypan blue exclusion and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. Proton (1H) and carbon (13C) nuclear magnetic resonance spectrometry (NMR) were used to identify the compounds that have been isolated from both Inula species.Results: The current findings were consistent for both trypan blue and MTT assays. The results showed that the most potent effect for I. vul was HepG2 (IC50 20 µg/ml, 27 µg/ml), and for I. vis on MCF7 (9 µg/ml, 15 µg/ml) and CaCO2 (12 µg/ml, 22 µg/ml) in the two mentioned assays respectively. However, insignificant differences were observed among the studied plants for each of the evaluated cells indicating comparable potencies. Quercetin, quercetin glycoside, and epicatechin derivatives were isolated by fractionation on column chromatography and identified using NMR spectroscopy.Conclusion: The antiproliferative activities of the two plants could be related to their content that is significant for high levels of secondary metabolites. The identification of those compounds is necessary to establish a relationship between their chemical structures and their activities

    Renewable Electricity Futures Study. Volume 4: Bulk Electric Power Systems: Operations and Transmission Planning

    Full text link
    The Renewable Electricity Futures (RE Futures) Study investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. The analysis focused on the sufficiency of the geographically diverse U.S. renewable resources to meet electricity demand over future decades, the hourly operational characteristics of the U.S. grid with high levels of variable wind and solar generation, and the potential implications of deploying high levels of renewables in the future. RE Futures focused on technical aspects of high penetration of renewable electricity; it did not focus on how to achieve such a future through policy or other measures. Given the inherent uncertainties involved with analyzing alternative long-term energy futures as well as the multiple pathways that might be taken to achieve higher levels of renewable electricity supply, RE Futures explored a range of scenarios to investigate and compare the impacts of renewable electricity penetration levels (30%-90%), future technology performance improvements, potential constraints to renewable electricity development, and future electricity demand growth assumptions. RE Futures was led by the National Renewable Energy Laboratory (NREL) and the Massachusetts Institute of Technology (MIT)

    Natural DNA-recombinations of Spodoptera littoralis NPV among field populations in Egypt

    Get PDF
    Six natural isolates belonging to #Spodotera littoralis$ NPV were identified. Using the restriction endonucleases Eco RI and Bam HI, the DNA profiles of each isolate from Giza, Menya, Kaliubeia-Kaha, Kafr El-Sheikh, Gharbeia and Kaliubeia-Tokh were differentiated from that of the reference Egypt-84. DNA electrophoretic profiles on different isolates collected 5 years later were compared to the difference type. The DNA sequence was not changed trough three serial passages of viral isolates in vivo, while several viral clones were obtained after the 4th passage. (Résumé d'auteur

    Foraging behaviour of Apis mellifera adansonii and its impact on pollination, fruit and seed yields of Citrullus lanatus at Nkolbisson (Yaoundé, Cameroon)

    Get PDF
    Honeybee (Apis mellifera adansonii Latreille (Hymenoptera: Apidae)) foraging activity was observed to evaluate its impact on pollination, fruit and seed yields of Citrullus lanatus (Thunb) Mansf (Cucurbitaceae) in the area of Yaoundé (Cameroon). Two lots of 775 female flowers were marked according to the presence or the absence of a protection for insect visits. The honey bees’ activity, the fruit set, the number of seeds per fruit were recorded. A. m. adansonii primarily foraged for nectar on C. lanatus throughout the whole blooming period of each plant and pollen collection was low. The mean maximum number of workers foraging at the same time was 331 ± 173 (n= 41) per 1000 flowers. The mean foraging speed was 10.20 ± 2.75 (n = 154) flowers per minute. The fruit set and the number of seeds per fruit of unprotected female flowers were significantly higher than those of female flowers protected from insects. A. m. adansonii pollination contributed 70.14% to the fruit set and seed yields. The conservation of A. m. adansonii colonies near C. lanatus population must be encouraged.Key words: Citrullus lanatus, Apis mellifera adansonii, pollination, yields, Cameroon.L’activité de butinage d’Apis mellifera adansonii Latreille (Hymenoptera : Apidae) a été étudiée afin d’évaluer son impact sur la pollinisation, les rendements fruitiers et grainiers de Citrullus lanatus (Thunb) Mansf (Cucurbitaceae) à Yaoundé (Cameroun). Deux lots ont été déterminés par le marquage de 775 fleurs femelles différant selon la présence ou l’absence de protection vis-à-vis des visites d’insectes. Le rythme saisonnier d’activité des abeilles domestiques, le taux de fructification des fleurs femelles et le nombre de graines par fruit ont été évalués. A. m. adansonii butinait les fleurs de C. lanatus tout au long de la période de floraison de chaque plante. Les butineuses prélevaient intensément le nectar pendant que la collecte du pollen était réduite. Le plus grand nombre d’ouvrières butinant simultanément était de 331 ± 173 (n = 41)par 1000 fleurs. La vitesse moyenne de butinage était de 10.20 ± 2.75 (n = 154) fleurs par minute. Le taux de fructification et le nombre moyen de graines matures par fruit des fleurs non protégées de l’activité des insectes étaient significativement élevés que ceux des fleurs femelles protégées. La contribution d’A. m. adansonii sur les rendements fruitiers et grainiers de C. lanatus était de 70.14% grâce à l’action pollinisatrice des ouvrières. La conservation des colonies d’A. m. adansonii à côté des populations de C. lanatus en fleurs doit être encouragée.Mots clés: Citrullus lanatus, Apis mellifera adansonii, pollinisation, rendements, Camerou

    Bailouts in a common market: a strategic approach

    Get PDF
    Governments in the EU grant Rescue and Restructure Subsidies to bail out ailing firms. In an international asymmetric Cournot duopoly we study effects of such subsidies on market structure and welfare. We adopt a common market setting, where consumers from the two countries form one market. We show that the subsidy is positive also when it fails to prevent the exit. The reason is a strategic effect, which forces the more efficient firm to make additional cost-reducing effort. When the exit is prevented, allocative and productive efficiencies are lower and the only gaining player is the rescued firm

    Crystal structures of complexes between aminoglycosides and decoding A site oligonucleotides: role of the number of rings and positive charges in the specific binding leading to miscoding

    Get PDF
    The crystal structures of six complexes between aminoglycoside antibiotics (neamine, gentamicin C1A, kanamycin A, ribostamycin, lividomycin A and neomycin B) and oligonucleotides containing the decoding A site of bacterial ribosomes are reported at resolutions between 2.2 and 3.0 Å. Although the number of contacts between the RNA and the aminoglycosides varies between 20 and 31, up to eight direct hydrogen bonds between rings I and II of the neamine moiety are conserved in the observed complexes. The puckered sugar ring I is inserted into the A site helix by stacking against G1491 and forms a pseudo base pair with two H-bonds to the Watson–Crick sites of the universally conserved A1408. This central interaction helps to maintain A1492 and A1493 in a bulged-out conformation. All these structures of the minimal A site RNA complexed to various aminoglycosides display crystal packings with intermolecular contacts between the bulging A1492 and A1493 and the shallow/minor groove of Watson–Crick pairs in a neighbouring helix. In one crystal, one empty A site is observed. In two crystals, two aminoglycosides are bound to the same A site with one bound specifically and the other bound in various ways in the deep/major groove at the edge of the A sites

    Super-sieving effect in phenol adsorption from aqueous solutions on nanoporous carbon beads

    Get PDF
    Removal of aromatic contaminants, like phenol, from water can be efficiently achieved by preferential adsorption on porous carbons which exhibit molecular sieving properties. Here, we present nanoporous carbon beads exhibiting an outstanding sieving effect in phenol adsorption from aqueous solution at neutral pH, which is evidenced experimentally and theoretically. The molecular sieving with pure phenol adsorbed phase is achieved by tuning the pore size and surface chemistry of the adsorbent. This study elucidates the essential role of hydrophobic interactions in narrow carbon micropores in removal and clean-up of water from organic pollutants. Furthermore, we suggest a new theoretical approach for evaluation of phenol adsorption capacity that is based on the Monte Carlo simulation of phenol adsorption with the relevance to the pore size distribution function determined by the density functional theory method from low temperature nitrogen adsorption

    Optimization of distyryl-Bodipy chromophores for efficient panchromatic sensitization in dye sensitized solar cells

    Get PDF
    Cataloged from PDF version of article.Versatility of Bodipy (4,4-difluoro-4-bora-3a, 4a-diaza-s-indacene) dyes was further expanded in recent dye-sensitized solar cell applications. Here we report a series of derivatives designed to address earlier problems in Bodipy sensitized solar cells. In the best case example, an overall efficiency of a modest 2.46% was achieved, but panchromatic nature of the dyes is quite impressive. This is the best reported efficiency in liquid electrolyte solar cells with Bodipy dyes as photosensitizers

    A major zebrafish polymorphism resource for genetic mapping

    Get PDF
    645,088 candidate polymorphisms in zebrafish were identified and positioned on genetic and physical maps as a resource for positional cloning

    Dipole polarizability of 120Sn and nuclear energy density functionals

    Full text link
    The electric dipole strength distribution in 120Sn between 5 and 22 MeV has been determined at RCNP Osaka from a polarization transfer analysis of proton inelastic scattering at E_0 = 295 MeV and forward angles including 0{\deg}. Combined with photoabsorption data an electric dipole polarizability \alpha_D(120Sn) = 8.93(36) fm^3 is extracted. The dipole polarizability as isovector observable par excellence carries direct information on the nuclear symmetry energy and its density dependence. The correlation of the new value with the well established \alpha_D(208Pb) serves as a test of its prediction by nuclear energy density functionals (EDFs). Models based on modern Skyrme interactions describe the data fairly well while most calculations based on relativistic Hamiltonians cannot.Comment: 6 pages, 4 figure
    • …
    corecore