Avezova N.R.,Academy of Sciences of Uzbekistan |
Kasimov F.S.,Academy of Sciences of Uzbekistan |
Niyazov S.K.,Gulistan State University
Applied Solar Energy (English translation of Geliotekhnika) | Year: 2010
The results of experimental field studies of thermal performance and heat efficiency of solar absorption capacious water heating collectors manufactured using local construction materials are presented. © Allerton Press, Inc., 2010.
Saidov A.S.,Academy of Sciences of Uzbekistan |
Saidov M.S.,Academy of Sciences of Uzbekistan |
Usmonov S.N.,Academy of Sciences of Uzbekistan |
Leiderman A.Y.,Academy of Sciences of Uzbekistan |
And 3 more authors.
Physics of the Solid State | Year: 2011
Single-crystal films of the substitutional solid solution (GaAs) 1 - x(ZnSe) x (0 ≤ x ≤ 0.80) on GaAs substrates have been grown using liquid phase epitaxy. The X-ray diffraction patterns, photoluminescence spectra, and current-voltage characteristics of the n-(GaAs)-p-(GaAs) 1 - x(ZnSe) x (0 ≤ x ≤ 0.80) heterostructures prepared have been investigated. The lattice parameters of the film a f = 5.6544 Å and the substrate a s = 5.6465 Å have been determined, and the profile of the molecular distribution of the solid solution components has been obtained. The photoluminescence spectrum of the (GaAs) 1 - x(ZnSe) x (0 ≤ x ≤ 0.80) films exhibits a narrow peak (against the background of the broad luminescence band) with a maximum in the luminescence intensity at a photon energy of 2.67 eV due to the presence of Zn-Se bonds in the structure (ZnSe is covalently bonded to the tetrahedral lattice of the GaAs matrix). It has been shown that the direct branch of the current-voltage characteristics of the structures under investigation is described by an exponential dependence I = I 0exp(qV/ckT) at low voltages (V & 0.3 V) and by a power-law dependence I ~ V α with exponents α = 4 at V = 0.4-0. 8 V, α = 2 at V = 0.8-1.4 V, and α = 1.5 at V & 2 V. The experimental results have been explained in the framework of the double-injection model for the n-p-p + structure under the condition that the concentration distribution of nonequilibrium charge carriers has a minimum. © 2011 Pleiades Publishing, Ltd.
Kuchboev A.E.,Academy of Sciences of Uzbekistan |
Krucken J.,Free University of Berlin |
Karimova R.R.,Academy of Sciences of Uzbekistan |
Ruziev B.H.,Karshi State University |
Pazilov A.,Gulistan State University
Journal of Helminthology | Year: 2016
Morphological analysis of lungworms collected among Caprinae from Uzbekistan resulted in the identification of four species of Protostrongylidae: Protostrongylus rufescens, Protostrongylus hobmaieri, Spiculocaulus leuckarti and Cystocaulus ocreatus. The following species were recorded as definitive hosts: Ovis aries, Ovis ammon, Ovis vignei, Capra hircus, Capra falconeri and Capra sibirica. The prevalence of P. rufescens reached 45.3%, followed by S. leuckarti and C. ocreatus with 31.7% and P. hobmaieri with 16.9%. The sex ratio ranged between 1:3.1 and 1:6.2, with P. hobmaieri showing the strongest predominance of females over males. The prevalence of infection of small ruminants with protostrongylid nematodes increased with the age of the hosts. Protostrongyles use terrestrial gastropods as intermediate hosts, and infective larvae were found in the species Vallonia costata, Gibbulinopsis signata, Pupilla muscorum, Pseudonapaeus albiplicata, Pseudonapaeus sogdiana, Leucozonella ferghanica, Xeropicta candacharica, Candaharia levanderi and Macrochlamys sogdiana. Xeropicta candacharica was the most abundant gastropod and had the highest prevalence of infection with protostrongylids. Adult X. candacharica had a significantly higher infection intensity than juveniles. The epidemiology of protostrongylid infections is dynamic and subject to considerable changes. Further characterization of the interaction of protostrongylid parasites with their terrestrial gastropods as intermediate hosts and Caprinae as definitive hosts is required to understand these processes and to monitor the effects of changing ecological contexts. Copyright © Cambridge University Press 2016
Basar N.,University of Technology Malaysia |
Basar N.,Liverpool John Moores University |
Talukdar A.D.,Liverpool John Moores University |
Talukdar A.D.,Assam University |
And 5 more authors.
Phytochemical Analysis | Year: 2014
Introduction Glycyrrhiza glabra L. (Fabaceae), commonly known as 'liquorice', is one of the most popular ingredients in several traditional herbal medicinal preparations, and glycyrrhizin is the major glycoside present in this plant. The content of glycyrrhizin may vary among G. glabra samples collected from various geographical origins, which may affect the therapeutic efficacy. Thus, quantification of glycyrrhizin in G. glabra samples is important. Objective To develop and validate a simple semi-preparative reversed-phase HPLC with photodiode array (PDA) method for separation and quantification of glycyrrhizin in nine samples of G. glabra root collected from various geographical origins. Methods Dried and ground root of G. glabra was Soxhlet-extracted sequentially with n-hexane and methanol (MeOH). The separation and quantification of glycyrrhizin was achieved on a C18 reversed-phase semi-preparative column using a gradient mobile phase, 30-100% solvent B in solvent A in 30 min (solvent A: 0.1% v/v trifluoroacetic acid (TFA) in water and solvent B: 0.1% v/v of TFA in MeOH), at a flow rate of 3.00 mL/min and UV detection at 254 nm. Results A simple semi-preparative reversed-phase HPLC/PDA method allowing clear separation and quantification of glycyrrhizin content in nine samples has been validated in terms of linearity, selectivity, limits of detection, precision, accuracy and detection. Concentration levels of glycyrrhizin were between 0.177 and 0.688% w/w of dry materials. Conclusion This method is precise, less time consuming and more cost effective, and can be used for the quality control of any G. glabra sample with regard to its glycyrrhizin contents. Copyright © 2014 John Wiley & Sons, Ltd.
PubMed | Selcuk University, University of Technology Malaysia, Liverpool John Moores University, ADAS UK Ltd. and 2 more.
Type: Journal Article | Journal: Phytochemical analysis : PCA | Year: 2016
Nuclear factor (erythroid-derived 2)-like factor 2 (Nrf2) is a transcription factor that regulates expression of many detoxification enzymes. Nrf2-antioxidant responsive element (Nrf2-ARE) signalling pathway can be a target for cancer chemoprevention. Glycyrrhiza glabra, common name, liquorice, is used as a sweetening and flavouring agent, and traditionally, to treat various ailments, and implicated to chemoprevention. However, its chemopreventive property has not yet been scientifically substantiated.To assess the ability of liquorice root samples to induce Nrf2 activation correlating to their potential chemopreventive property.The ability of nine methanolic extracts of liquorice root samples, collected from various geographical origins, to induce Nrf2 activation was determined by the luciferase reporter assay using the ARE-reporter cell line, AREc32. The antioxidant properties were determined by the 2,2-diphenyl-1-picryhydrazyl (DPPH) and the ferric-reducing antioxidant power (FRAP) assays.All extracts exhibited free-radical-scavenging property (RC50 =136.39-635.66g/mL). The reducing capacity of ferrous ion was 214.46-465.59M Fe(II)/g. Nrf2 activation indicated that all extracts induced expression of ARE-driven luciferase activity with a maximum induction of 2.3 fold relative to control. These activities varied for samples from one geographical location to another.The present findings add to the existing knowledge of cancer chemoprevention by plant-derived extracts or purified phytochemicals, particularly the potential use of liquorice for this purpose. Copyright 2016 John Wiley & Sons, Ltd.
PubMed | Selcuk University, ADAS UK Ltd., Liverpool John Moores University and Gulistan State University
Type: Comparative Study | Journal: Phytotherapy research : PTR | Year: 2015
Glycyrrhiza glabra L. (Fabaceae), commonly known as liquorice, is a well-known medicinal plant. Roots of this plant have long been used as a sweetening and flavouring agent in food and pharmaceutical products, and also as a traditional remedy for cough, upper and lower respiratory ailments, kidney stones, hepatitis C, skin disorder, cardiovascular diseases, diabetes, gastrointestinal ulcers and stomach ache. Previous pharmacological and clinical studies have revealed its antitussive, antiinflammatory, antiviral, antimicrobial, antioxidant, immunomodulatory, hepatoprotective and cardioprotective properties. While glycyrrhizin, a sweet-tasting triterpene saponin, is the principal bioactive compound, several bioactive flavonoids and isoflavonoids are also present in the roots of this plant. In the present study, the cytotoxicity of the methanol extracts of nine samples of the roots of G.glabra, collected from various geographical origins, was assessed against immortal human keratinocyte (HaCaT), lung adenocarcinoma (A549) and liver carcinoma (HepG2) cell lines using the in vitro 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazoliumbromide cell toxicity/viability assay. Considerable variations in levels of cytotoxicity were observed among various samples of G.glabra.
Tvrda E.,Slovak University of Agriculture |
Kovacik A.,Slovak University of Agriculture |
Tusimova E.,Slovak University of Agriculture |
Paal D.,Constantine the Philosopher University |
And 3 more authors.
Journal of Animal Science and Biotechnology | Year: 2016
Background: Lycopene (LYC) is a natural carotenoid with powerful reactive oxygen species (ROS) scavenging activities. The aim of this study was to investigate if lycopene has the ability to reverse ROS-mediated alterations to the motility, viability and intracellular antioxidant profile of bovine spermatozoa subjected to ferrous ascorbate (FeAA). Spermatozoa were washed out of fresh bovine semen, suspended in 2.9 % sodium citrate and subjected to LYC treatment (0.25, 0.5, 1 or 2 mmol/L) in the presence or absence of FeAA (150 μmol/L FeSO4 and 750 μmol/L ascorbic acid) during a 6 h in vitro culture. Spermatozoa motion characteristics were assessed using the SpermVision™ computer-aided sperm analysis (CASA) system. Cell viability was examined with the metabolic activity (MTT) assay, ROS generation was quantified via luminometry and the nitroblue-tetrazolium (NBT) test was applied to quantify the intracellular superoxide formation. Cell lysates were prepared at the end of the in vitro culture to investigate the intracellular activity of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) as well as the concentrations of glutathione (GSH) and malondialdehyde (MDA). Results: FeAA treatment led to a reduced spermatozoa motility (P < 0.001), viability (P < 0.001) and a decline of the antioxidant capacity of spermatozoa (P < 0.001) but increased the ROS generation (P < 0.001), superoxide production (P < 0.001) and lipid peroxidation (P < 0.001). LYC administration resulted in a preservation of the spermatozoa motion parameters (P < 0.001), mitochondrial activity (P < 0.001) and antioxidant characteristics (P < 0.001 with respect to SOD; P < 0.01 in relation to CAT; P < 0.05 as for GPx and GSH) with a concentration range of 1 and 2 mmol/L LYC revealed to be the most effective. Conclusions: Our results suggest that LYC exhibits significant ROS-scavenging and antioxidant properties which may prevent spermatozoa alterations caused by oxidative stress, and preserve the functionality of male reproductive cells. © 2016 The Author(s).
Gulistan State University | Entity website
Gulistan State University | Entity website
Gulistan State University | Entity website
Guliston Davlat Universiteti