20 research outputs found

    Phytoplasmas and their insect vectors in Lithuania

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    The aim of the research was to identify the phytoplasmas detected in insects that were found on various phytoplasma-infected plants, and to reveal phytoplasma insect-vectors as well as phytogenetical relationships of identified phytoplasmas. From previous research, we already know a few mostly widespread phytoplasma groups, subgroups, and many of their host plants in Lithuania. The data on potential vectors of these bacteria are very scarce in Lithuania. The identification and research of insect vectors will help to create more effective strategies and systems to fight with phytoplasmal infections. Identification of phytoplasmas and their vectors will provide important data for research of ecology, distribution, origin, epidemiology, and ways of spreading of these pathogens. Such information is beneficial for plant protection institutions and plant growers in Lithuania and neighbouring countries. It will help to ascertain possible invasive insect species and phytoplasma strains in Lithuania. During this research for the first time in Lithuania, we determined possible phytoplasma insect vectors using molecular biology methods. Most of the detected phytoplasma subgroups were found in the identified insect species for the first time in Lithuania and worldwide. Our data on new potential insect vector species extend the spectrum of phytoplasma vectors in our region. Phytoplasmas were detected for the first time in five plant species in Lithuania. We identified in this work one new phytoplasma subgroup for Lithuania and world, and one new subgroup for Lithuania and their plant-hosts. New phytoplasma subgroups and their host plants found during this study contribute to biodiversity and distribution research of phytoplasma detected in Europe and worldwide

    Fitoplazmos ir jų vabzdžiai pernešėjai Lietuvoje

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    The aim of the research was to identify the phytoplasmas detected in insects that were found on various phytoplasma-infected plants, and to reveal phytoplasma insect-vectors as well as phytogenetical relationships of identified phytoplasmas. From previous research, we already know a few mostly widespread phytoplasma groups, subgroups, and many of their host plants in Lithuania. The data on potential vectors of these bacteria are very scarce in Lithuania. The identification and research of insect vectors will help to create more effective strategies and systems to fight with phytoplasmal infections. Identification of phytoplasmas and their vectors will provide important data for research of ecology, distribution, origin, epidemiology, and ways of spreading of these pathogens. Such information is beneficial for plant protection institutions and plant growers in Lithuania and neighbouring countries. It will help to ascertain possible invasive insect species and phytoplasma strains in Lithuania. During this research for the first time in Lithuania, we determined possible phytoplasma insect vectors using molecular biology methods. Most of the detected phytoplasma subgroups were found in the identified insect species for the first time in Lithuania and worldwide. Our data on new potential insect vector species extend the spectrum of phytoplasma vectors in our region. Phytoplasmas were detected for the first time in five plant species in Lithuania. We identified in this work one new phytoplasma subgroup for Lithuania and world, and one new subgroup for Lithuania and their plant-hosts. New phytoplasma subgroups and their host plants found during this study contribute to biodiversity and distribution research of phytoplasma detected in Europe and worldwide

    Mechanical Properties and Durability of Rubberized and Glass Powder Modified Rubberized Concrete for Whitetopping Structures

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    This paper analyzes concrete fine aggregate (sand) modification by scrap tire rubber particles-fine crumb rubber (FCR) and coarse crumb rubber (CCR) of fraction 0/1 mm. Such rubberized concrete to get better bonding properties were modified by car-boxylated styrene butadiene rubber (SBR) latex and to gain the strength were modified by glass waste. The following tests—slump test, fresh concrete density, fresh concrete air content, compressive strength, flexural strength, fracture energy, freezing-thawing, porosity parameter, and scanning electron microscope—were conducted for rubberized concretes. From experiments, we can see that fresh concrete properties decreased when crumb rubber content has increased. Mostly it is related to crumb rubber (CR) lower specific gravity nature and higher fineness compared with changed fine aggregate-sand. In this research, we obtained a slight loss of compressive strength when CR was used in concrete However, these rubberized concretes with a small amount of rubber provided sufficient compressive strength results (greater than 50 MPa). Due to the pozzolanic reaction, we see that compressive strength results after 56 days in glass powder modified samples increased by 11–13% than 28 days com-pressive strengths, while at the same period control samples increased its compressive strength about 2.5%. Experiments have shown that the flexural strength of rubberized concrete with small amounts of CR increased by 3.4–15.8% compared to control mix, due the fact that rubber is an elastic material and it will absorb high energy and perform positive bending toughness. The test results indicated that CR can intercept the tensile stress in concrete and make the deformation more plastic. Fracturing of such conglomerate concrete is not brittle, there is no abrupt post-peak load drop and gradually continues after the maximum load is exceeded. Such concrete requires much higher fracture energy. It was obtained that FCR particles (lower than A300) will entrap more micropores content than coarse rubbers because due to their high specific area. Freezing-thawing results have confirmed that Kf values can be conveniently used to predict freeze-thaw resistance and durability of concrete. The test has shown that modification of concrete with 10 kg fine rubber waste will lead to similar mechanical and durability properties of concrete as was obtained in control concrete with 2 kg of prefabricated air bubbles

    secA gene suitability for fast and easy identification of Phytoplasmas by RFLP analysis

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    n this study we investigated the secA gene as possible marker to supplement the classification scheme based on 16S rRNA sequences. We cloned and sequenced secA gene and its flanking region of 'Ca. P. asteris' CPh strain phytoplasma, as well as 1997 bp length secA gene fragment of Canada peach X-disease CX and 1327 bp fragment of 'Ca. P. ziziphi' JWB. This helped us to select a primer pair for a single step PCR that can amplify similar to 1200 kb length fragment of secA gene from different phytoplasma groups. We propose that this fragment could be used in RFLP analysis to quickly identify and distinguish 16SrI-A, I-B, I-C, I-D, III-A, III-B, III-E, III-F, III-H, V-B, XII-B and XXI-A subgroup phytoplasmas using just two restriction endonucleases

    The investigations on properties of self-healing concrete with crystalline admixture and recycled concrete waste

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    The concept of self-healing concrete is becoming more necessary as sustainability in construction is more desirable. Amongst the current solutions in this technology are autogenous, chemical, and bacterial self-healing. It is paramount that secondary raw materials be used in the production of selfhealing concrete as a form of a sustainable solution. Therefore, in this paper, the admixture “Betocrete-CP-360-WP”, which is a crystallizing waterproofing admixture with hydrophobic effect and is 100% recyclable, has been used and its effect on the physical, chemical, and mechanical properties of concrete, as well as selfhealing capabilities of concrete, have been determined. According to the obtained results, the crystalline additive “Betocrete-CP-360-WP” has no effect on density and slightly increases the amount of entrained air in the concrete mix. However, it does decrease the workability of the concrete mixture which could prove problematic in transportation to the construction site or in concreting in general. Also, with the crystalline admixture in the concrete mix, a 60% reduction in concrete compressive strength after one day of hardening has been estimated, but after 7 and 28 days, the strength attained is within the ranges of the control samples. In addition, concrete containing Betocrete-CP360-WP was 30% less water permeable as compared to control samples. The self-healing efficiency of the concrete was determined by a water flow test through a formed crack (approximately 0.35 mm wide). This was done by gluing a plastic pipe to the top of the cracked concrete specimens and maintaining a constant pressure of the water in the pipe. The experiment was continued for 28 days, and the crack self-healing efficiency of the concrete was calculated from the differences in the amount of water passed through the crack before healing and after 7, 14, 21 and 28 days of the healing process. After 28 days of the water flow test, the cracks in the concrete with the crystalline admixture and recycled concrete dust were completely healed, while the control specimens were not

    Fenolinių rūgščių ir fenilpropanoidų įvertinimas vaistinėje žaliavoje

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    Phenolic acids and phenylpropanoids have an important biological activity and are therapeutic agents of crude drugs. Development of validated analysis techniques of these phytotherapeutic agents (fingerprinting and assay procedures) is an important practice for efficacy, safety, and quality control of herbal drug preparations. The aim of the present work was to study analytical capabilities of the evaluation of selected phenolic acids and phenylpropanoids: caffeic acid, chlorogenic acid, cinnamic acid, coumaric acid, ferulic acid, gallic acid, protocatechuic (3,4-dihydroxybenzoic) acid, rosmarinic acid, vanillic acid, and vanillin. Optimization and validation procedures of rapid and simple method of reversed-phase high-performance liquid chromatography were carried out. The mobile phase of the optimized chromatographic method consisted of methanol and 0.5% acetic acid solvent in water. For the application of method, two kinds of raw materials were chosen: propolis and the Herba Origani. Coumaric acid is the dominating phenolic acid of propolis (2785 mg/g). Results of analysis of Herba Origani demonstrated high quantities (6376 mg/g) of rosmarinic and protocatechuic (1485 mg/g) acids in the samples

    Scanning Electron Microscopy: Extrapolation of 3D Data from SEM Micrographs

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    n this manuscript we suggest a three-dimensional reconstruction technique to fully characterize structural performance of solid materials. The described technique extrapolates, measures and interprets the 3-dimensional data which is extracted from SEM images, obtained from different angles. Further, finer results were achieved by extrapolating of spatial data from three or more sample images using visual reconstruction software applications. Gold particles, silicon wafers and dendrites were selected as model materials for the spatial 3D surface reconstruction. For comparison and proof-of-concept, stereoscopy technique was also included into the research.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.11101</p

    Fenolinių rūgščių ir fenilpropanoidų įvertinimas vaistinėje žaliavoje

    No full text
    Phenolic acids and phenylpropanoids have an important biological activity and are therapeutic agents of crude drugs. Development of validated analysis techniques of these phytotherapeutic agents (fingerprinting and assay procedures) is an important practice for efficacy, safety, and quality control of herbal drug preparations. The aim of the present work was to study analytical capabilities of the evaluation of selected phenolic acids and phenylpropanoids: caffeic acid, chlorogenic acid, cinnamic acid, coumaric acid, ferulic acid, gallic acid, protocatechuic (3,4-dihydroxybenzoic) acid, rosmarinic acid, vanillic acid, and vanillin. Optimization and validation procedures of rapid and simple method of reversed-phase high-performance liquid chromatography were carried out. The mobile phase of the optimized chromatographic method consisted of methanol and 0.5% acetic acid solvent in water. For the application of method, two kinds of raw materials were chosen: propolis and the Herba Origani. Coumaric acid is the dominating phenolic acid of propolis (2785 mg/g). Results of analysis of Herba Origani demonstrated high quantities (6376 mg/g) of rosmarinic and protocatechuic (1485 mg/g) acids in the samples

    16SrI-a pogrupio fitoplazmų sukelta epidemija sode Vilniaus rajone Lietuvoje

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    Here we report on a plant disease caused by insect-transmitted unculturable plant pathogenic bacteria detected in a private garden in Vilnius region. Samples of symptomatic peas (Pisum sativum L.), nasturtium (Tropaeolum majus L.), strawberry (Fragaria × ananassa Duchesne) and zucchini (Cucurbita pepo var. giromontina) plant tissues were collected. Based on the molecular technique, the Internet tools and phylogenetic analysis, these pathogens were identified as phytoplasmas and classified in phytoplasma RFLP (restriction fragment length polymorphism) group 16SrI, subgroup A. Because this pathogen may be spread by insect-vector that comes from the wild nature, the phytoplasmas could cause a problem in agriculture of Lithuania

    The Influence of Expanded Glass and Expanded Clay on Lightweight Aggregate Shotcrete Properties

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    In the construction industry, the selection of sustainable materials leads to a movement towards more sustainable construction. In this study, lightweight aggregate shotcrete based on expanded glass (EG) and expanded clay (EC) is investigated. The goal of the study is to determine the influence of EG and EC inclusion on the properties of shotcrete. Ordinary Portland cement (OPC) powder with supplementary cementitious materials, such as silica fume and ground glass waste, are used as binders. The mechanical, physical and morphological properties, as well as the mineral and oxygen compositions, are obtained through compressive and flexural strength tests, thermal conductivity measurements, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM–EDX), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analysis. In this study, the mechanical, physical and thermal properties and waste utilization as cement supplementary materials are balanced. The shotcrete samples show that a density of 790 kg/m3 had a good thermal performance (thermal conductivity coefficient of 0.174 W/(m·K)) with the sufficient compressive strength of 6.26 MPa
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