199 research outputs found

    Influence of exogenous urea on photosynthetic pigments, 14CO2 uptake, and urease activity in Elodea densa-environmental implications

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    This paper analyzes the effect of exogenous urea in increased concentration gradient (0, 100, 500 and 1,000 mg L-1) on photosynthetic pigments (measured spectrophotometrically), uptake of 14CO2 (using radioisotope), and urease activity (by measuring ammonia with Nessler's reagent) in leaves of Elodea densa Planch. We have observed that low concentration of urea (100 mg L-1) stimulates the accumulation of photosynthetic pigments and intensifies photosynthesis in E. densa, whereas high concentration (1,000 mg L-1) suppresses these processes. Urease activity increased by approximately 2.7 and 8 fold when exogenous urea concentrations were 100 and 500 mg L-1, respectively. However, exogenous urea in high concentration (1,000 mg L-1) decreased urease activity by 1.5 fold compared to the control. The necessity of mitigating urea and other nitrogen-containing compounds (NH3 from urea) in water bodies has been discussed with emphasis on the potential for phytoremediation of urea using common water weed viz. E. densa. © 2013 Springer-Verlag Berlin Heidelberg

    Developing a modern thermal strengthening technique for regulated fishplate cooling

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    A modern ecologically friendly technique for fishplate (joint bar) thermal strengthening by regulated water cooling is proposed. The proposed technique can successfully replace the conventional one - oil quenching - due to making the cooling process more controlled by obtaining a uniform temperature distribution over fishplate elements with a different mass such as heads and the wet. The oil quenching process is an out of control fire hazardous one and requires controlling the permanent cooling capability, fishplate flushing after the operation. It is necessary to utilize the oil and to have a special ventilation system. As a mineral oil substitute, the usage of polymer media has been investigated. Within the time, the polymer solution needs to be recycled; the high cost of polymer concentrates also plays an important role. Quenching by water spraying is the most ecological and controlled type of thermal strengthening. The technique was validated by a test bench experiment and implemented in the metallurgical industry. The mechanical properties have been obtained to meet the GOST 4133-73 technical requirements. Moreover, the analysis made showed that when the controlled cooling device is fitted into the line existing due to exclusion of the hardening tank and washing machine from the processing flow it is possible to save energy, exclude the expenditures for acquisition, the preparation of oil and washing mixtures as well as for regeneration of the oils used and washing solutions. © 2014 WIT Press.International Journal of Safety and Security Engineering;International Journal of Sustainable Development and Planning;WIT Transactions on Ecology and the Environmen

    RETROSPECTIVE EVALUATION OF THE FETUS AND NEWBORN ON THE BASIS OF INDICATORS OF FETAL HEMODYNAMICS AND TRANSCRANIAL CEREBRAL OXIMETRY

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    Purpose: identify the correlation between antenatal evaluation of fetus and newborn according to cerebral fetal hemodynamic and transcranial cerebral oximetryMaterials and methods. Clinical examination of 90 women before and in 1 termoflabor and 90 newborns. Ultrasound study of fetoplacental complex with Doppler were done to all pregnant women. Study of blood flow were done during functional test wit hapnoe. Cerebral hemodynamic of newborns evaluated by transcranial cerebral oximetry immediately after birth, on the 3rd and 5th days.Results: There are strict correlation between the Dopplerindices, indices of functional test and indicators of trans cranial cerebral oximetry of newborn.Summary: Doppler study with functional tests before and in 1 termoflabor allows to assess the state of blood circulation in the vessels of the placenta and fetus objectively, noninvasively and economically available

    Cryptic Diversity in Paramecium multimicronucleatum Revealed with a Polyphasic Approach

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    Paramecium (Ciliophora) systematics is well studied, and about twenty morphological species have been described. The morphological species may include several genetic species. How-ever, molecular phylogenetic analyses revealed that the species diversity within Paramecium could be even higher and has raised a problem of cryptic species whose statuses remain uncertain. In the present study, we provide the morphological and molecular characterization of two novel Paramecium species. While Paramecium lynni n. sp., although morphologically similar to P. multimicronucleatum, is phylogenetically well separated from all other Paramecium species, Paramecium fokini n. sp. appears to be a cryptic sister species to P. multimicronucleatum. The latter two species can be distinguished only by molecular methods. The number and structure of micronuclei, traditionally utilized to discriminate species in Paramecium, vary not only between but also within each of the three studied species and, thus, cannot be considered a reliable feature for species identification. The geographic distribution of the P. multimicronucleatum and P. fokini n. sp. strains do not show defined patterns, still leaving space for a role of the geographic factor in initial speciation in Paramecium. Future findings of new Paramecium species can be predicted from the molecular data, while morphological characteristics appear to be unstable and overlapping at least in some species

    THE ROLE OF THE CHANGED PRODUCTION OF INTRACELLULAR REGULATORS IN PATHOGENESIS OF PRETERM DELIVERY

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    Purpose: To determine the influence of the changed production of bioactive components on the trophoblast invasion disorders and as a result development of preterm delivery.Materials and methods: 69 pregnant women were under observation, among them there were 48 women with the threatened miscarriage in the 1st trimester and preterm delivery and 21 women with physiological gestation. The determination of the content of glycodelin-A, follistatin, IL-1β and TNF-α in the blood serum during the 1st trimester and in case of preterm delivery in the 34th - 37th weeks was realized by means of immunoenzyme method.Results: An evident imbalance of intracellular bioregulators that determine nidation of the ovum and chorion formation was revealed.Summary: A high level of TNF-α causes the disorder of calcium ion concentration in myometrium cells that leads to initiation of preterm delivery

    THE FACTORS OF CELLULAR REGULATION OF THE UTERUS CONTRACTIVE ACTIVITY BY PHYSIOLOGICAL ACT OF DELIVERY AND BY UTERINE INERTIA

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    Purpose. To develop a method of prediction of primary uterine inertia on the basis of study of cytokine and vasoactive bioregulator content dynamics.Materials and methods. The material for the research was blood of women taken in the end of gestation (38-40 weeks) and also in the I period of delivery over time from 23 women with physiological act of delivery and from 19 – with uterine inertia.Results. By primary uterine inertia there is an increase of relaxin production by 2 times and a decrease of TNF-α production: before delivery – by 1.5 times, during delivery – by 2 times, relative to the data by physiological delivery. Differently directed changes of TGF-β1 and IL-1β content – increase of the first one and decrease of the second one – are one of the reasons of low generation of nitric oxide as a result of reduction of NO-synthase activity under the action of these cytokines. High level of relaxin neutralizes the endogenous oxytocin action and the decrease of TNF-α and nitric oxide production causes changes in the content of intracellular calcium in myometrium cells.Summary: The detected character of the intracellular regulation disturbance of the uterus contractive activity is a basis for the development of uterine inertia

    Dibenzo[ f,h]furazano[3,4- b]quinoxalines: Synthesis by Intramolecular Cyclization through Direct Transition Metal-Free C-H Functionalization and Electrochemical, Photophysical, and Charge Mobility Characterization

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    Herein, we describe the synthesis of unsymmetrically substituted dibenzo[f,h]furazano[3,4-b]quinoxalines by intramolecular cyclization through direct transition metal-free C-H functionalization. The electrochemical and photophysical properties for several polycycles have been measured. In thin films of the dibenzo[f,h]furazano[3,4-b]quinoxalines, hole mobility is in the order of 10-4 cm2 V-1 s-1. The results show that the HOMO and LUMO energy levels are appropriate for using the compounds as hole-transport materials in thin-film devices, in particular, organic and perovskite solar cells. Copyright © 2020 American Chemical Society.Russian Foundation for Basic Research, RFBR: 18-33-00103-mol_aRussian Science Foundation, RSF: 18-13-00409The research was financially supported by the Russian Science Foundation (project no. 18-13-00409). Y.A.K would like to acknowledge the financial support for the part of the synthetic section from the Russian Foundation for Basic Research (research project no. 18-33-00103-mol_a). The authors are grateful to Grigory A. Kim for carrying out the DFT calculations, which were performed by using “Uran” supercomputer of the Institute of Mathematics and Mechanics of the Ural Branch of the Russian Academy of Sciences. NMR experiments were carried out by using equipment of the Center for Joint Use “Spectroscopy and Analysis of Organic Compounds” at the Postovsky Institute of Organic Synthesis of the Ural Branch of the Russian Academy of Sciences

    Benzo[ b]selenophene/thieno[3,2- b]indole-Based N,S,Se-Heteroacenes for Hole-Transporting Layers

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    Two series of new N,S,Se-heteroacenes, namely, 6H-benzo[4′,5′]selenopheno[2′,3′:4,5]thieno[3,2-b]indoles and 12H-benzo[4″,5″]selenopheno[2″,3″:4′,5′]thieno[2′,3′4,5]thieno[3,2-b]indoles, were successfully obtained using an effective strategy based on Fiesselmann thiophene and Fischer indole synthesis. The new molecules exhibit a large optical band gap (2.82 eV < Egopt < 3.23 eV) and their highest occupied molecular orbital (HOMO) energy formed by the plane π-core ranges between -5.2 and -5.6 eV, with the narrower optical band gap and lower HOMO level corresponding to selenated heteroacenes. In thin solid films of the heteroacenes, hole mobility measured using the conventional CELIV technique ranges between 10-5 and 10-4 cm2·V-1·s-1. All these make the proposed condensed-ring compounds a promising platform for the development of hole-transporting materials applicable in organic electronics. Copyright © 2020 American Chemical Society.The research (synthesis of new heteroacenes and investigation of their semiconductor properties) was financially supported by the Russian Science Foundation (project no. 18-13-00409). N.S.D. and N.A.R. would like to acknowledge the financial support for the analytical studies of synthesized compounds from the Ministry of Education and Science of the Russian Federation within the framework of the State Assignment for Research (project no. AAAA-A19-119012490006-1). The authors are grateful to Grigory A. Kim for carrying out the DFT calculations which were performed using ⟨⟨Uran⟩⟩ supercomputer of the Institute of Mathematic and Mechanics of the Ural Branch of the Russian Academy of Sciences. The XRD measurements were performed using the equipment of CKP FMI IPCE RAS
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