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Sample records for osssi2 enhances resistance

  1. Induced resistance: an enhancement of basal resistance?

    NARCIS (Netherlands)

    Vos, M. de; Robben, C.; Pelt, J.A. van; Loon, L.C. van; Pieterse, C.M.J.

    2002-01-01

    Upon primary pathogen attack, plants activate resistance mechanisms at the site of infection. Besides this so-called basal resistance, plants have also the ability to enhance their defensive capacity against future pathogen attack. There are at least two types of biologically induced resistance.

  2. Enhanced radiation resistant fiber optics

    International Nuclear Information System (INIS)

    Lyons, P.B.; Looney, L.D.

    1993-01-01

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures

  3. Enhanced radiation resistant fiber optics

    Science.gov (United States)

    Lyons, P.B.; Looney, L.D.

    1993-11-30

    A process for producing an optical fiber having enhanced radiation resistance is provided, the process including maintaining an optical fiber within a hydrogen-containing atmosphere for sufficient time to yield a hydrogen-permeated optical fiber having an elevated internal hydrogen concentration, and irradiating the hydrogen-permeated optical fiber at a time while the optical fiber has an elevated internal hydrogen concentration with a source of ionizing radiation. The radiation source is typically a cobalt-60 source and the fiber is pre-irradiated with a dose level up to about 1000 kilorads of radiation. 4 figures.

  4. Enhancing banana weevil ( Cosmopolites sordidus ) resistance by ...

    African Journals Online (AJOL)

    Enhancing banana weevil (Cosmopolites sordidus) resistance by plant genetic modification: A perspective. Andrew Kiggundu, Michael Pillay, Altus Viljoen, Clifford Gold, Wilberforce Tushemereirwe, Karl Kunert ...

  5. Vitamins for enhancing plant resistance.

    Science.gov (United States)

    Boubakri, Hatem; Gargouri, Mahmoud; Mliki, Ahmed; Brini, Faiçal; Chong, Julie; Jbara, Moez

    2016-09-01

    This paper provides an overview on vitamins with inducing activities in plants, the molecular and cellular mechanisms implicated, and the hormonal signalling-network regulating this process. Moreover, it reports how vitamins might be part of the molecular events linked to induced resistance by the conventional elicitors. Induced resistance (IR), exploiting the plant innate-defense system is a sustainable strategy for plant disease control. In the last decade, vitamins have been proven to act as inducers of disease resistance, and these findings have received an important attention owing to their safety and cost effectiveness. Vitamins, including thiamine (TH, vitamin B1), riboflavin (RF, vitamin B2), menadione sodium bisulfite (MSB, vitamin K3), Para-aminobenzoic acid (PABA, vitamin Bx), and folic acid (FA, vitamin B9) provided an efficient protection against a wide range of pathogens through the modulation of specific host-defense facets. However, other vitamins, such as ascorbic acid (AA, vitamin C) and tocopherols (vitamin E), have been shown to be a part of the molecular mechanisms associated to IR. The present review is the first to summarize what vitamins are acting as inducers of disease resistance in plants and how could they be modulated by the conventional elicitors. Thus, this report provides an overview on the protective abilities of vitamins and the molecular and cellular mechanisms underlying their activities. Moreover, it describes the hormonal-signalling network regulating vitamin-signal transduction during IR. Finally, a biochemical model describing how vitamins are involved in the establishment of IR process is discussed.

  6. Strength gradient enhances fatigue resistance of steels

    Science.gov (United States)

    Ma, Zhiwei; Liu, Jiabin; Wang, Gang; Wang, Hongtao; Wei, Yujie; Gao, Huajian

    2016-02-01

    Steels are heavily used in infrastructure and the transportation industry, and enhancing their fatigue resistance is a major challenge in materials engineering. In this study, by introducing a gradient microstructure into 304 austenitic steel, which is one of the most widely used types of stainless steel, we show that a strength gradient substantially enhances the fatigue life of the material. Pre-notched samples with negative strength gradients in front of the notch’s tip endure many more fatigue cycles than do samples with positive strength gradients during the crack initiation stage, and samples with either type of gradient perform better than do gradient-free samples with the same average yield strength. However, as a crack grows, samples with positive strength gradients exhibit better resistance to fatigue crack propagation than do samples with negative gradients or no gradient. This study demonstrates a simple and promising strategy for using gradient structures to enhance the fatigue resistance of materials and complements related studies of strength and ductility.

  7. Enhancement of seismic resistance of buildings

    Directory of Open Access Journals (Sweden)

    Claudiu-Sorin Dragomir

    2014-03-01

    Full Text Available The objectives of the paper are both seismic instrumentation for damage assessment and enhancing of seismic resistance of buildings. In according with seismic design codes in force the buildings are designed to resist at seismic actions. Due to the time evolution of these design provisions, there are buildings that were designed decades ago, under the less stringent provisions. The conceptual conformation is nowadays provided in all Codes of seismic design. According to the Code of seismic design P100-1:2006 the asymmetric structures do not have an appropriate seismic configuration; they have disadvantageous distribution of volumes, mass and stiffness. Using results of temporary seismic instrumentation the safety condition of the building may be assessed in different phases of work. Based on this method, the strengthening solutions may be identified and the need of seismic joints may be emphasised. All the aforementioned ideas are illustrated through a case study. Therefore it will be analysed the dynamic parameter evolution of an educational building obtained in different periods. Also, structural intervention scenarios to enhance seismic resistance will be presented.

  8. Using biotechnology to enhance host resistance to aflatoxin ...

    African Journals Online (AJOL)

    Host resistance is the most widely explored strategy for eliminating aflatoxin contamination by Aspergillus flavus. Breeding strategies for developing resistant corn germplasm have been enhanced by the development of new screening tools for field inoculation and for laboratory screening. RFLP analysis of corn populations ...

  9. Fracture resistance enhancement of layered structures by multiple cracks

    DEFF Research Database (Denmark)

    Goutianos, Stergios; Sørensen, Bent F.

    2016-01-01

    A theoretical model is developed to test if the fracture resistance of a layered structure can be increased by introducing weak layers changing the cracking mechanism. An analytical model, based on the J integral, predicts a linear dependency between the number of cracks and the steady state...... fracture resistance. A finite element cohesive zone model, containing two cracking planes for simplicity, is used to check the theoretical model and its predictions. It is shown that for a wide range of cohesive law parameters, the numerical predictions agree well quantitatively with the theoretical model....... Thus, it is possible to enhance considerably the fracture resistance of a structure by adding weak layers....

  10. Pluripotent cells display enhanced resistance to mutagenesis

    Directory of Open Access Journals (Sweden)

    Daniel J. Cooper

    2017-03-01

    Full Text Available Pluripotent cells have been reported to exhibit lower frequencies of point mutations and higher levels of DNA repair than differentiated cells. This predicts that pluripotent cells are less susceptible to mutagenic exposures than differentiated cells. To test this prediction, we used a lacI mutation-reporter transgene system to assess the frequency of point mutations in multiple lines of mouse pluripotent embryonic stem cells and induced pluripotent cells, as well as in multiple lines of differentiated fibroblast cells, before and after exposure to a moderate dose of the mutagen, methyl methanesulfonate. We also measured levels of key enzymes in the base excision repair (BER pathway in each cell line before and after exposure to the mutagen. Our results confirm that pluripotent cells normally maintain lower frequencies of point mutations than differentiated cells, and show that differentiated cells exhibit a large increase in mutation frequency following a moderate mutagenic exposure, whereas pluripotent cells subjected to the same exposure show no increase in mutations. This result likely reflects the higher levels of BER proteins detectable in pluripotent cells prior to exposure and supports our thesis that maintenance of enhanced genetic integrity is a fundamental characteristic of pluripotent cells.

  11. Herbivory enhances the resistance of mangrove forest to cordgrass invasion.

    Science.gov (United States)

    Zhang, Yihui; Meng, Hanyu; Wang, Yi; He, Qiang

    2018-06-01

    The biotic resistance hypothesis proposes that biotic interactions, such as competition and herbivory, resist the establishment and spread of non-native species. The relative and interactive role of competition and herbivory in resisting plant invasions, however, remains poorly understood. We investigated the interactive role of competition and herbivory (by the native rodent Rattus losea) in resisting Spartina alterniflora (cordgrass) invasions into mangrove forests. In southern China, although exotic cordgrass numerically dominates intertidal mudflats and open gaps in mangrove forests, intact forests appear to be highly resistant to cordgrass invasion. A field transplant and rodent exclusion experiment showed that while the impact of rodent grazing on cordgrass was weak on mangrove forest edges and open mudflats, rodent grazing strongly suppressed cordgrass in mangrove understory habitats. A greenhouse experiment confirmed a synergistic interaction between grazing and light availability (a proxy for mangrove shading and light competition) in suppressing cordgrass establishment, with the strongest impacts of grazing in low light conditions that likely weakened cordgrass to survive and resprout. When both were present, as in mangrove understory habitats, grazing and low light acted in concert to eliminate cordgrass establishment, resulting in resistance of mangrove forests to cordgrass invasion. Our results reveal that grazing by native herbivores can enhance the resistance of mangrove forests to cordgrass invasion in southern China, and suggest that investigating multifactor interactions may be critical to understanding community resistance to exotic invasions. © 2018 by the Ecological Society of America.

  12. Enhanced antioxidative responses of a salt-resistant wheat cultivar ...

    African Journals Online (AJOL)

    Enhanced antioxidative responses of a salt-resistant wheat cultivar facilitate its adaptation to salt stress. L Chen, H Yin, J Xu, X Liu. Abstract. Wheat cultivars capable of accumulating minerals under salt stress are of considerable interest for their potential to improve crop productivity and crop quality. This study addressed the ...

  13. Enhanced tomato disease resistance primed by arbuscular mycorrhizal fungus.

    Science.gov (United States)

    Song, Yuanyuan; Chen, Dongmei; Lu, Kai; Sun, Zhongxiang; Zeng, Rensen

    2015-01-01

    Roots of most terrestrial plants form symbiotic associations (mycorrhiza) with soil- borne arbuscular mycorrhizal fungi (AMF). Many studies show that mycorrhizal colonization enhances plant resistance against pathogenic fungi. However, the mechanism of mycorrhiza-induced disease resistance remains equivocal. In this study, we found that mycorrhizal inoculation with AMF Funneliformis mosseae significantly alleviated tomato (Solanum lycopersicum Mill.) early blight disease caused by Alternaria solani Sorauer. AMF pre-inoculation led to significant increases in activities of β-1,3-glucanase, chitinase, phenylalanine ammonia-lyase (PAL) and lipoxygenase (LOX) in tomato leaves upon pathogen inoculation. Mycorrhizal inoculation alone did not influence the transcripts of most genes tested. However, pathogen attack on AMF-inoculated plants provoked strong defense responses of three genes encoding pathogenesis-related proteins, PR1, PR2, and PR3, as well as defense-related genes LOX, AOC, and PAL, in tomato leaves. The induction of defense responses in AMF pre-inoculated plants was much higher and more rapid than that in un-inoculated plants in present of pathogen infection. Three tomato genotypes: a Castlemart wild-type (WT) plant, a jasmonate (JA) biosynthesis mutant (spr2), and a prosystemin-overexpressing 35S::PS plant were used to examine the role of the JA signaling pathway in AMF-primed disease defense. Pathogen infection on mycorrhizal 35S::PS plants led to higher induction of defense-related genes and enzymes relative to WT plants. However, pathogen infection did not induce these genes and enzymes in mycorrhizal spr2 mutant plants. Bioassays showed that 35S::PS plants were more resistant and spr2 plants were more susceptible to early blight compared with WT plants. Our finding indicates that mycorrhizal colonization enhances tomato resistance to early blight by priming systemic defense response, and the JA signaling pathway is essential for mycorrhiza

  14. Enhanced Macrophage M1 Polarization and Resistance to Apoptosis Enable Resistance to Plague.

    Science.gov (United States)

    Pachulec, Emilia; Abdelwahed Bagga, Rym Ben; Chevallier, Lucie; O'Donnell, Hope; Guillas, Chloé; Jaubert, Jean; Montagutelli, Xavier; Carniel, Elisabeth; Demeure, Christian E

    2017-09-15

    Susceptibility to infection is in part genetically driven, and C57BL/6 mice resist various pathogens through the proinflammatory response of their M1 macrophages (MPs). However, they are susceptible to plague. It has been reported elsewhere that Mus spretus SEG mice resist plague and develop an immune response characterized by a strong recruitment of MPs. The responses of C57BL/6 and SEG MPs exposed to Yersinia pestis in vitro were examined. SEG MPs exhibit a stronger bactericidal activity with higher nitric oxide production, a more proinflammatory polarized cytokine response, and a higher resistance to Y. pestis-induced apoptosis. This response was not specific to Y. pestis and involved a reduced sensitivity to M2 polarization/signal transducer and activator of transcription 6 activation and inhibition of caspase 8. The enhanced M1 profile was inducible in C57BL/6 MPs in vitro, and when transferred to susceptible C57BL/6 mice, these MPs significantly increased survival of bubonic plague. MPs can develop an enhanced functional profile beyond the prototypic M1, characterized by an even more potent proinflammatory response coordinated with resistance to killing. This programming plays a key role in the plague-resistance phenotype and may be similarly significant in other highly lethal infections, suggesting that orienting the MP response may represent a new therapeutic approach. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

  15. Laser processing of cast iron for enhanced erosion resistance

    International Nuclear Information System (INIS)

    Chen, C.H.; Altstetter, C.J.; Rigsbee, J.M.

    1984-01-01

    The surfaces of nodular and gray cast iron have been modified by CO 2 laser processing for enhanced hardness and erosion resistance. Control of the near-surface microstructure was achieved primarily by controlling resolidification of the laser melted layer through variations in laser beam/target interaction time and beam power density. Typical interaction times and power densities used were 5 msec and 500 kW/cm 2 . Two basic kinds of microstructure can be produced-a feathery microstructure with high hardness (up to 1245 HV) and a dendritic microstructure with a metastable, fully austenitic matrix and lower hardness (600 to 800 HV). Erosion testing was done using slurries of SiO 2 or SiC in water. Weight loss and crater profile measurements were used to evaluate the erosion characteristics of the various microstructures. Both ductile and gray cast iron showed marked improvement in erosion resistance after laser processing

  16. Resistance transition assisted geometry enhanced magnetoresistance in semiconductors

    International Nuclear Information System (INIS)

    Luo, Zhaochu; Zhang, Xiaozhong

    2015-01-01

    Magnetoresistance (MR) reported in some non-magnetic semiconductors (particularly silicon) has triggered considerable interest owing to the large magnitude of the effect. Here, we showed that MR in lightly doped n-Si can be significantly enhanced by introducing two diodes and proper design of the carrier path [Wan, Nature 477, 304 (2011)]. We designed a geometrical enhanced magnetoresistance (GEMR) device whose room-temperature MR ratio reaching 30% at 0.065 T and 20 000% at 1.2 T, respectively, approaching the performance of commercial MR devices. The mechanism of this GEMR is: the diodes help to define a high resistive state (HRS) and a low resistive state (LRS) in device by their openness and closeness, respectively. The ratio of apparent resistance between HRS and LRS is determined by geometry of silicon wafer and electrodes. Magnetic field could induce a transition from LRS to HRS by reshaping potential and current distribution among silicon wafer, resulting in a giant enhancement of intrinsic MR. We expect that this GEMR could be also realized in other semiconductors. The combination of high sensitivity to low magnetic fields and large high-field response should make this device concept attractive to the magnetic field sensing industry. Moreover, because this MR device is based on a conventional silicon/semiconductor platform, it should be possible to integrate this MR device with existing silicon/semiconductor devices and so aid the development of silicon/semiconductor-based magnetoelectronics. Also combining MR devices and semiconducting devices in a single Si/semiconductor chip may lead to some novel devices with hybrid function, such as electric-magnetic-photonic properties. Our work demonstrates that the charge property of semiconductor can be used in the magnetic sensing industry, where the spin properties of magnetic materials play a role traditionally

  17. Enhancing VVER annular proliferation resistance fuel with minor actinides

    International Nuclear Information System (INIS)

    Chang, G. S.

    2007-01-01

    Key aspects of the Global Nuclear Energy Partnership (GNEP) are to significantly advance the science and technology of nuclear energy systems and the Advanced Fuel Cycle (AFC) program. It consists of both innovative nuclear reactors and innovative research in separation and transmutation. To accomplish these goals, international cooperation is very important and public acceptance is crucial. The merits of nuclear energy are high-density energy, with low environmental impacts (i.e. almost zero greenhouse gas emission). Planned efforts involve near term and intermediate-term improvements in fuel utilization and recycling in current light water reactors (LWRs) as well as the longer-term development of new nuclear energy systems that offer much improved fuel utilization and proliferation resistance, along with continued advances in operational safety. The challenges are solving the energy needs of the world, protection against nuclear proliferation, the problem of nuclear waste, and the global environmental problem. To reduce spent fuel for storage and enhance the proliferation resistance for the intermediate-term, there are two major approaches (a) increase the discharged spent fuel burnup in the advanced LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 2 38Pu and 2 40Pu isotopes ratio to enhance the proliferation resistance, and (b) use of transuranic nuclides ( 2 37Np and 2 41Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope ratio of 2 38Pu /Pu. For future advanced nuclear systems, the minor actinides (MA) are viewed more as a resource to be recycled, or transmuted to less hazardous and possibly more useful forms, rather than simply as a waste stream to be disposed of in expensive repository facilities. As a result, MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors

  18. Enhancing BWR proliferation resistance fuel with minor actinides

    Science.gov (United States)

    Chang, Gray S.

    2009-03-01

    To reduce spent fuel for storage and enhance the proliferation resistance for the intermediate-term, there are two major approaches (a) increase the discharged spent fuel burnup in the advanced light water reactor- LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu isotopes ratio to enhance the proliferation resistance, and (b) use of transuranic nuclides ( 237Np and 241Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope ratio of 238Pu/Pu. For future advanced nuclear systems, minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. As a result, MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In the study, a typical boiling water reactor (BWR) fuel unit lattice cell model with UO 2 fuel pins will be used to investigate the effectiveness of minor actinide reduction approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance in the intermediate-term goal for future nuclear energy systems. To account for the water coolant density variation from the bottom (0.76 g/cm 3) to the top (0.35 g/cm 3) of the core, the axial coolant channel and fuel pin were divided to 24 nodes. The MA transmutation characteristics at different elevations were compared and their impact on neutronics criticality discussed. The concept of MARA, which involves the use of transuranic nuclides ( 237Np and/or 241Am), significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in

  19. Mast Cells Can Enhance Resistance to Snake and Honeybee Venoms

    Science.gov (United States)

    Metz, Martin; Piliponsky, Adrian M.; Chen, Ching-Cheng; Lammel, Verena; Åbrink, Magnus; Pejler, Gunnar; Tsai, Mindy; Galli, Stephen J.

    2006-07-01

    Snake or honeybee envenomation can cause substantial morbidity and mortality, and it has been proposed that the activation of mast cells by snake or insect venoms can contribute to these effects. We show, in contrast, that mast cells can significantly reduce snake-venom-induced pathology in mice, at least in part by releasing carboxypeptidase A and possibly other proteases, which can degrade venom components. Mast cells also significantly reduced the morbidity and mortality induced by honeybee venom. These findings identify a new biological function for mast cells in enhancing resistance to the morbidity and mortality induced by animal venoms.

  20. A Recombinant Measles Vaccine with Enhanced Resistance to Passive Immunity.

    Science.gov (United States)

    Julik, Emily; Reyes-Del Valle, Jorge

    2017-09-21

    Current measles vaccines suffer from poor effectiveness in young infants due primarily to the inhibitory effect of residual maternal immunity on vaccine responses. The development of a measles vaccine that resists such passive immunity would strongly contribute to the stalled effort toward measles eradication. In this concise communication, we show that a measles virus (MV) with enhanced hemagglutinin (H) expression and incorporation, termed MVvac2-H2, retained its enhanced immunogenicity, previously established in older mice, when administered to very young, genetically modified, MV-susceptible mice in the presence of passive anti-measles immunity. This immunity level mimics the sub-neutralizing immunity prevalent in infants too young to be vaccinated. Additionally, toward a more physiological small animal model of maternal anti-measles immunity interference, we document vertical transfer of passive anti-MV immunity in genetically-modified, MV susceptible mice and show in this physiological model a better MVvac2-H2 immunogenic profile than that of the parental vaccine strain. In sum, these data support the notion that enhancing MV hemagglutinin incorporation can circumvent in vivo neutralization. This strategy merits additional exploration as an alternative pediatric measles vaccine.

  1. Enhanced methanol production in plants provides broad spectrum insect resistance.

    Directory of Open Access Journals (Sweden)

    Sameer Dixit

    Full Text Available Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR and spectra showed up to 16 fold higher methanol as compared to control wild type (WT plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid and Bemisia tabaci (whitefly, respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants.

  2. Enhanced Methanol Production in Plants Provides Broad Spectrum Insect Resistance

    Science.gov (United States)

    Dixit, Sameer; Upadhyay, Santosh Kumar; Singh, Harpal; Sidhu, Om Prakash; Verma, Praveen Chandra; K, Chandrashekar

    2013-01-01

    Plants naturally emit methanol as volatile organic compound. Methanol is toxic to insect pests; but the quantity produced by most of the plants is not enough to protect them against invading insect pests. In the present study, we demonstrated that the over-expression of pectin methylesterase, derived from Arabidopsis thaliana and Aspergillus niger, in transgenic tobacco plants enhances methanol production and resistance to polyphagous insect pests. Methanol content in the leaves of transgenic plants was measured using proton nuclear spectroscopy (1H NMR) and spectra showed up to 16 fold higher methanol as compared to control wild type (WT) plants. A maximum of 100 and 85% mortality in chewing insects Helicoverpa armigera and Spodoptera litura larvae was observed, respectively when fed on transgenic plants leaves. The surviving larvae showed less feeding, severe growth retardation and could not develop into pupae. In-planta bioassay on transgenic lines showed up to 99 and 75% reduction in the population multiplication of plant sap sucking pests Myzus persicae (aphid) and Bemisia tabaci (whitefly), respectively. Most of the phenotypic characters of transgenic plants were similar to WT plants. Confocal microscopy showed no deformities in cellular integrity, structure and density of stomata and trichomes of transgenic plants compared to WT. Pollen germination and tube formation was also not affected in transgenic plants. Cell wall enzyme transcript levels were comparable with WT. This study demonstrated for the first time that methanol emission can be utilized for imparting broad range insect resistance in plants. PMID:24223989

  3. Enhancing motivation for change in treatment-resistant eating disorders.

    Science.gov (United States)

    Vitousek, K; Watson, S; Wilson, G T

    1998-06-01

    Denial and resistance to change are prominent features in most patients with anorexia nervosa. The egosyntonic quality of symptoms can contribute to inaccuracy in self-report, avoidance of treatment, difficulties in establishing a therapeutic relationship, and high rates of attrition and relapse. Individuals with bulimia nervosa are typically more motivated to recover, but often ambivalent about forfeiting the ideal of slenderness and the protective functions of binge-purge behavior. Few attempts have been made to assess denial and resistance in the eating disorders, or to examine alternative strategies for enhancing motivation to change. Review of the clinical literature indicates a striking convergence of recommendations across conceptually distinct treatment approaches. Clinicians are encouraged to acquire a frame of reference that can help them understand the private experience of individuals with eating disorders, empathize with their distress at the prospect of weight gain, and acknowledge the difficulty of change. The Socratic method seems particularly well-suited to work with this population because of its emphasis on collaboration, openness, curiosity, patience, focused and systematic inquiry, and individual discovery. Four themes are crucial in engaging reluctant eating-disordered clients in therapy: the provision of psychoeducational material, an examination of the advantages and disadvantages of symptoms, the explicit use of experimental strategies, and an exploration of personal values.

  4. Enhanced resistance to Spodoptera litura in endophyte infected cauliflower plants.

    Science.gov (United States)

    Thakur, Abhinay; Kaur, Sanehdeep; Kaur, Amarjeet; Singh, Varinder

    2013-04-01

    Endophytic fungi, which live within host plant tissues without causing any visible symptom of disease, are important mediators of plant-herbivore interactions. These endophytes enhance resistance of host plant against insect herbivores mainly by productions of various alkaloid based defensive compounds in the plant tissue or through alterations of plant nutritional quality. Two endophytic fungi, i.e., Nigrospora sp. and Cladosporium sp., were isolated from Tinospora cordifolia (Thunb.) Miers, a traditional indian medicinal plant. Cauliflower (Brassica oleracea L.) plants were inoculated with these two endophytic fungi. The effect of endophyte infected and uninfected cauliflower plants were measured on the survival and development of Spodoptera litura (Fab.), a polyphagous pest. Endophyte infected cauliflower plants showed resistance to S. litura in the form of significant increase in larval and pupal mortality in both the fungi. Inhibitory effects of endophytic fungi also were observed on adult emergence, longevity, reproductive potential, as well as hatchability of eggs. Thus, it is concluded that antibiosis to S. litura could be imparted by artificial inoculation of endophytes and this could be used to develop alternative ecologically safe control strategies.

  5. Enhanced Transmission of Drug-Resistant Parasites to Mosquitoes following Drug Treatment in Rodent Malaria

    OpenAIRE

    Bell, Andrew S.; Huijben, Silvie; Paaijmans, Krijn P.; Sim, Derek G.; Chan, Brian H. K.; Nelson, William A.; Read, Andrew F.

    2012-01-01

    The evolution of drug resistant Plasmodium parasites is a major challenge to effective malaria control. In theory, competitive interactions between sensitive parasites and resistant parasites within infections are a major determinant of the rate at which parasite evolution undermines drug efficacy. Competitive suppression of resistant parasites in untreated hosts slows the spread of resistance; competitive release following treatment enhances it. Here we report that for the murine model Plasm...

  6. Plasmid mediated enhancement of uv resistance in Streptococcus faecalis

    International Nuclear Information System (INIS)

    Miehl, R.; Miller, M.; Yasbin, R.E.

    1980-01-01

    A 38.5-Mdal plasmid of Streptococcus faecalis subdp. zymogenes has been shown to enhance survival following uv irradiation. In addition, the presence of this plasmid increases the mutation frequencies following uv irradiation and enhanced W-reactivation. The data presented indicate that S. faecalis has an inducible error-prone repair system and that the plasmid enhances these repair functions

  7. Transgenic Strategies for Enhancement of Nematode Resistance in Plants

    Directory of Open Access Journals (Sweden)

    Muhammad A. Ali

    2017-05-01

    Full Text Available Plant parasitic nematodes (PPNs are obligate biotrophic parasites causing serious damage and reduction in crop yields. Several economically important genera parasitize various crop plants. The root-knot, root lesion, and cyst nematodes are the three most economically damaging genera of PPNs on crops within the family Heteroderidae. It is very important to devise various management strategies against PPNs in economically important crop plants. Genetic engineering has proven a promising tool for the development of biotic and abiotic stress tolerance in crop plants. Additionally, the genetic engineering leading to transgenic plants harboring nematode resistance genes has demonstrated its significance in the field of plant nematology. Here, we have discussed the use of genetic engineering for the development of nematode resistance in plants. This review article also provides a detailed account of transgenic strategies for the resistance against PPNs. The strategies include natural resistance genes, cloning of proteinase inhibitor coding genes, anti-nematodal proteins and use of RNA interference to suppress nematode effectors. Furthermore, the manipulation of expression levels of genes induced and suppressed by nematodes has also been suggested as an innovative approach for inducing nematode resistance in plants. The information in this article will provide an array of possibilities to engineer resistance against PPNs in different crop plants.

  8. Temperature and mixing effects on electrical resistivity of carbon fiber enhanced concrete

    International Nuclear Information System (INIS)

    Chang, Christiana; Song, Gangbing; Gao, Di; Mo, Y L

    2013-01-01

    In this paper, the effect of temperature and mixing procedure on the electrical resistivity of carbon fiber enhanced concrete is investigated. Different compositions of concrete containing varying concentrations of carbon fiber into normal and self-consolidating concrete (SCC) were tested under DC electrical loading over the temperature range −10 to 20 °C. The electrical resistivity of the bulk samples was calculated and compared against temperature. It was observed that there is an inverse exponential relationship between resistivity and temperature which follows the Arrhenius relationship. The bulk resistivity decreased with increasing fiber concentration, though data from SCC indicates a saturation limit beyond which electrical resistivity begins to drop. The activation energy of the bulk electrically conductive concrete was calculated and compared. While SCC exhibited the lowest observed electrical resistance, the activation energy was similar amongst SCC and surfactant enhanced concrete, both of which were lower than fiber dispersed in normal concrete. (paper)

  9. Technical features to enhance proliferation resistance of nuclear energy systems

    International Nuclear Information System (INIS)

    2010-01-01

    It is generally accepted that proliferation resistance is an essential issue for the continued development and sustainability of nuclear energy. Several comprehensive assessment activities on the proliferation resistance of the nuclear fuel cycle have previously been completed, notably the International Nuclear Fuel Cycle Evaluation (INFCE) carried out under the auspices of the IAEA, and the Non-proliferation Alternative Systems Assessment Program (NASAP) review carried out by the USA. There have been, however, relatively few comprehensive treatments of the issue following these efforts in the 1970s. However, interest in and concern about this issue have increased recently, particularly because of greater interest in innovative nuclear fuel cycles and systems. In 2000, the IAEA initiated the International Project on Innovative Nuclear Reactors and Fuel Cycles (INPRO) and the US Department of Energy initiated the Generation IV International Forum (GIF). These projects are aimed at the selection and development of concepts of innovative nuclear energy systems and fuel cycles. Proliferation resistance is one of the fundamental considerations for both projects. In this context, the IAEA in 2001 initiated a study entitled 'Technical Aspects of Increasing Proliferation Resistance of the Nuclear Fuel Cycle'. This task is not intended as an effort to assess the merits of a particular fuel cycle system for the future, but to describe a qualitative framework for an examination of the proliferation resistance provided by the intrinsic features of an innovative nuclear energy system and fuel cycle. This task also seeks to provide a high level survey of a variety of innovative nuclear energy systems and fuel cycles with respect to that framework. The concept of proliferation resistance is considered in terms of intrinsic features and extrinsic measures. The intrinsic features, sometimes referred to as the physical/technical aspects, are those features that result from the

  10. Pyramids of QTLs enhance host-plant resistance and Bt-mediated resistance to leaf-chewing insects in soybean.

    Science.gov (United States)

    Ortega, María A; All, John N; Boerma, H Roger; Parrott, Wayne A

    2016-04-01

    QTL-M and QTL-E enhance soybean resistance to insects. Pyramiding these QTLs with cry1Ac increases protection against Bt-tolerant pests, presenting an opportunity to effectively deploy Bt with host-plant resistance genes. Plant resistance to leaf-chewing insects minimizes the need for insecticide applications, reducing crop production costs and pesticide concerns. In soybean [Glycine max (L.) Merr.], resistance to a broad range of leaf-chewing insects is found in PI 229358 and PI 227687. PI 229358's resistance is conferred by three quantitative trait loci (QTLs): M, G, and H. PI 227687's resistance is conferred by QTL-E. The letters indicate the soybean Linkage groups (LGs) on which the QTLs are located. This study aimed to determine if pyramiding PI 229358 and PI 227687 QTLs would enhance soybean resistance to leaf-chewing insects, and if pyramiding these QTLs with Bt (cry1Ac) enhances resistance against Bt-tolerant pests. The near-isogenic lines (NILs): Benning(ME), Benning(MGHE), and Benning(ME+cry1Ac) were developed. Benning(ME) and Benning(MGHE) were evaluated in detached-leaf and greenhouse assays with soybean looper [SBL, Chrysodeixis includens (Walker)], corn earworm [CEW, Helicoverpa zea (Boddie)], fall armyworm [FAW, Spodoptera frugiperda (J.E. Smith)], and velvetbean caterpillar [VBC, Anticarsia gemmatalis (Hübner)]; and in field-cage assays with SBL. Benning(ME+cry1Ac) was tested in detached-leaf assays against SBL, VBC, and Southern armyworm [SAW, Spodoptera eridania (Cramer)]. In the detached-leaf assay, Benning(ME) showed the strongest antibiosis against CEW, FAW, and VBC. In field-cage conditions, Benning(ME) and Benning(MGHE) suffered 61 % less defoliation than Benning. Benning(ME+cry1Ac) was more resistant than Benning(ME) and Benning (cry1Ac) against SBL and SAW. Agriculturally relevant levels of resistance in soybean can be achieved with just two loci, QTL-M and QTL-E. ME+cry1Ac could present an opportunity to protect the durability of Bt

  11. Encapsulation of strontium aluminate phosphors to enhance water resistance and luminescence

    International Nuclear Information System (INIS)

    Zhu Yong; Zeng Jianghua; Li Wenyu; Xu Li; Guan Qiu; Liu Yingliang

    2009-01-01

    Strontium aluminate SrAl 2 O 4 :Eu 2+ ,Dy 3+ phosphors are chemically unstable against water or even moisture. To enhance the water resistance of the phosphors, an encapsulation was performed by direct surface reactions with phosphoric acid (H 3 PO 4 ). The morphology, surface structure, surface element composition, water resistance, luminescence, and photoacoustic spectrum of the phosphors before and after encapsulation were discussed. Experimental results showed that phosphors were perfectly encapsulated by amorphous layers in nanoscale and crystalline layers in microscale under different conditions. The water resistance of phosphors was greatly enhanced by the two types of layer. More importantly, the amorphous layers enhanced the luminescence of phosphors markedly. The possible mechanism for the enhancements was also proposed.

  12. Strategies for Enhanced Crop Resistance to Insect Pests.

    Science.gov (United States)

    Douglas, Angela E

    2018-04-29

    Insect pests are responsible for substantial crop losses worldwide through direct damage and transmission of plant diseases, and novel approaches that complement or replace broad-spectrum chemical insecticides will facilitate the sustainable intensification of food production in the coming decades. Multiple strategies for improved crop resistance to insect pests, especially strategies relating to plant secondary metabolism and immunity and microbiome science, are becoming available. Recent advances in metabolic engineering of plant secondary chemistry offer the promise of specific toxicity or deterrence to insect pests; improved understanding of plant immunity against insects provides routes to optimize plant defenses against insects; and the microbiomes of insect pests can be exploited, either as a target or as a vehicle for delivery of insecticidal agents. Implementation of these advances will be facilitated by ongoing advances in plant breeding and genetic technologies.

  13. Materials That Enhance Efficiency and Radiation Resistance of Solar Cells

    Science.gov (United States)

    Sun, Xiadong; Wang, Haorong

    2012-01-01

    A thin layer (approximately 10 microns) of a novel "transparent" fluorescent material is applied to existing solar cells or modules to effectively block and convert UV light, or other lower solar response waveband of solar radiation, to visible or IR light that can be more efficiently used by solar cells for additional photocurrent. Meanwhile, the layer of fluorescent coating material remains fully "transparent" to the visible and IR waveband of solar radiation, resulting in a net gain of solar cell efficiency. This innovation alters the effective solar spectral power distribution to which an existing cell gets exposed, and matches the maximum photovoltaic (PV) response of existing cells. By shifting a low PV response waveband (e.g., UV) of solar radiation to a high PV response waveband (e.g. Vis-Near IR) with novel fluorescent materials that are transparent to other solar-cell sensitive wavebands, electrical output from solar cells will be enhanced. This approach enhances the efficiency of solar cells by converting UV and high-energy particles in space that would otherwise be wasted to visible/IR light. This innovation is a generic technique that can be readily implemented to significantly increase efficiencies of both space and terrestrial solar cells, without incurring much cost, thus bringing a broad base of economical, social, and environmental benefits. The key to this approach is that the "fluorescent" material must be very efficient, and cannot block or attenuate the "desirable" and unconverted" waveband of solar radiation (e.g. Vis-NIR) from reaching the cells. Some nano-phosphors and novel organometallic complex materials have been identified that enhance the energy efficiency on some state-of-the-art commercial silicon and thin-film-based solar cells by over 6%.

  14. Enhanced oxidation resistance of carbon fiber reinforced lithium aluminosilicate composites by boron doping

    International Nuclear Information System (INIS)

    Xia, Long; Jin, Feng; Zhang, Tao; Hu, Xueting; Wu, Songsong; Wen, Guangwu

    2015-01-01

    Highlights: • C f /LAS composites exhibit enhanced oxidation resistance by boron doping. • Boron doping is beneficial to the improvement of graphitization degree of carbon fibers. • Graphitization of carbon fibers together with the decrease of viscosity of LAS matrix is responsible to the enhancement of oxidation resistance of C f /LAS composites. - Abstract: Carbon fiber reinforced lithium aluminosilicate matrix composites (C f /LAS) modified with boron doping were fabricated and oxidized for 1 h in static air. Weight loss, residual strength and microstructure were analyzed. The results indicate that boron doping has a remarkable effect on improving the oxidation resistance for C f /LAS. The synergism of low viscosity of LAS matrix at high temperature and formation of graphite crystals on the surface of carbon fibers, is responsible for excellent oxidation resistance of the boron doped C f /LAS.

  15. Copper-resistant bacteria enhance plant growth and copper phytoextraction.

    Science.gov (United States)

    Yang, Renxiu; Luo, Chunling; Chen, Yahua; Wang, Guiping; Xu, Yue; Shen, Zhenguo

    2013-01-01

    In this study, we investigated the role of rhizospheric bacteria in solubilizing soil copper (Cu) and promoting plant growth. The Cu-resistant bacterium DGS6 was isolated from a natural Cu-contaminated soil and was identified as Pseudomonas sp. DGS6. This isolate solubilized Cu in Cu-contaminated soil and stimulated root elongation of maize and sunflower. Maize was more sensitive to inoculation with DGS6 than was sunflower and exhibited greater root elongation. In pot experiment, inoculation with DGS6 increased the shoot dry weight of maize by 49% and sunflower by 34%, and increased the root dry weight of maize by 85% and sunflower by 45%. Although the concentrations of Cu in inoculated and non-inoculated seedlings did not differ significantly, the total accumulation of Cu in the plants increased after inoculation. DGS6 showed a high ability to solubilize P and produce iron-chelating siderophores, as well as significantly improved the accumulation of P and Fe in both maize and sunflower shoots. In addition, DGS6 produced indole-3-acetic acid (IAA) and ACC deaminase, which suggests that it may modulate ethylene levels in plants. The bacterial strain DGS6 could be a good candidate for re-vegetation of Cu-contaminated sites. Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.

  16. The potyviral suppressor of RNA silencing confers enhanced resistance to multiple pathogens

    International Nuclear Information System (INIS)

    Pruss, Gail J.; Lawrence, Christopher B.; Bass, Troy; Li Qingshun Q.; Bowman, Lewis H.; Vance, Vicki

    2004-01-01

    Helper component-protease (HC-Pro) is a plant viral suppressor of RNA silencing, and transgenic tobacco expressing HC-Pro has increased susceptibility to a broad range of viral pathogens. Here we report that these plants also exhibit enhanced resistance to unrelated heterologous pathogens. Tobacco mosaic virus (TMV) infection of HC-Pro-expressing plants carrying the N resistance gene results in fewer and smaller lesions compared to controls without HC-Pro. The resistance to TMV is compromised but not eliminated by expression of nahG, which prevents accumulation of salicylic acid (SA), an important defense signaling molecule. HC-Pro-expressing plants are also more resistant to tomato black ring nepovirus (TBRV) and to the oomycete Peronospora tabacina. Enhanced TBRV resistance is SA-independent, whereas the response to P. tabacina is associated with early induction of markers characteristic of SA-dependent defense. Thus, a plant viral suppressor of RNA silencing enhances resistance to multiple pathogens via both SA-dependent and SA-independent mechanisms

  17. The potyviral suppressor of RNA silencing confers enhanced resistance to multiple pathogens.

    Science.gov (United States)

    Pruss, Gail J; Lawrence, Christopher B; Bass, Troy; Li, Qingshun Q; Bowman, Lewis H; Vance, Vicki

    2004-03-01

    Helper component-protease (HC-Pro) is a plant viral suppressor of RNA silencing, and transgenic tobacco expressing HC-Pro has increased susceptibility to a broad range of viral pathogens. Here we report that these plants also exhibit enhanced resistance to unrelated heterologous pathogens. Tobacco mosaic virus (TMV) infection of HC-Pro-expressing plants carrying the N resistance gene results in fewer and smaller lesions compared to controls without HC-Pro. The resistance to TMV is compromised but not eliminated by expression of nahG, which prevents accumulation of salicylic acid (SA), an important defense signaling molecule. HC-Pro-expressing plants are also more resistant to tomato black ring nepovirus (TBRV) and to the oomycete Peronospora tabacina. Enhanced TBRV resistance is SA-independent, whereas the response to P. tabacina is associated with early induction of markers characteristic of SA-dependent defense. Thus, a plant viral suppressor of RNA silencing enhances resistance to multiple pathogens via both SA-dependent and SA-independent mechanisms.

  18. Rapid identification of bacterial resistance to Ciprofloxacin using surface-enhanced Raman spectroscopy

    Science.gov (United States)

    Kastanos, Evdokia; Hadjigeorgiou, Katerina; Pitris, Costas

    2014-02-01

    Due to its effectiveness and broad coverage, Ciprofloxacin is the fifth most prescribed antibiotic in the US. As current methods of infection diagnosis and antibiotic sensitivity testing (i.e. an antibiogram) are very time consuming, physicians prescribe ciprofloxacin before obtaining antibiogram results. In order to avoid increasing resistance to the antibiotic, a method was developed to provide both a rapid diagnosis and the sensitivity to the antibiotic. Using Surface Enhanced Raman Spectroscopy, an antibiogram was obtained after exposing the bacteria to Ciprofloxacin for just two hours. Spectral analysis revealed clear separation between sensitive and resistant bacteria and could also offer some inside into the mechanisms of resistance.

  19. Resisting distraction and response inhibition trigger similar enhancements of future performance.

    Science.gov (United States)

    Bissett, Patrick G; Grant, Lauren D; Weissman, Daniel H

    2017-10-01

    Resisting distraction and response inhibition are crucial aspects of cognitive control. Interestingly, each of these abilities transiently improves just after it is utilized. Competing views differ, however, as to whether utilizing either of these abilities (e.g., resisting distraction) enhances future performance involving the other ability (e.g., response inhibition). To distinguish between these views, we combined a Stroop-like task that requires resisting distraction with a restraint variant of the stop-signal task that requires response inhibition. We observed similar sequential-trial effects (i.e., performance enhancements) following trials in which participants (a) resisted distraction (i.e., incongruent go trials) and (b) inhibited a response (i.e., congruent stop trials). First, the congruency effect in go trials, which indexes overall distractibility, was smaller after both incongruent go trials and congruent stop trials than it was after congruent go trials. Second, stop failures were less frequent after both incongruent go trials and congruent stop trials than after congruent go trials. A control experiment ruled out the possibility that perceptual conflict or surprise engendered by occasional stop signals triggers sequential-trial effects independent of stopping. Thus, our findings support a novel, integrated view in which resisting distraction and response inhibition trigger similar sequential enhancements of future performance. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Outcomes of an Enhanced Surveillance Program for Carbapenem-Resistant Enterobacteriaceae

    OpenAIRE

    Fitzpatrick, Margaret; Zembower, Teresa; Malczynski, Michael; Qi, Chao; Bolon, Maureen K.

    2014-01-01

    Optimal surveillance strategies for identifying patients colonized with and at risk for transmitting carbapenem-resistant Enterobacteriaceae (CRE) are urgently needed. We instituted an enhanced surveillance program for CRE that identified unrecognized CRE-colonized patients but failed to identify possible CRE transmissions. We also identified risk factors associated with transmitting CRE.

  1. Utilizing Genetic Resources and Precision Agriculture to Enhance Resistance to Biotic and Abiotic Stress in Watermelon

    Directory of Open Access Journals (Sweden)

    Mihail KANTOR

    2018-03-01

    Full Text Available Originally from Africa, watermelon is a staple crop in South Carolina and rich source of important phytochemicals that promote human health. As a result of many years of domestication and selection for desired fruit quality, modern watermelon cultivars are susceptible to biotic and abiotic stress. The present review discusses how genetic selection and breeding combined with geospatial technologies (precision agriculture may help enhance watermelon varieties for resistance to biotic and abiotic stress. Gene loci identified and selected in undomesticated watermelon accessions are responsible for resistance to diseases, pests and abiotic stress. Vegetable breeding programs use traditional breeding methodologies and genomic tools to introduce gene loci conferring biotic or abiotic resistance into the genome background of elite watermelon cultivars. This continuous approach of collecting, evaluating and identifying useful genetic material is valuable for enhancing genetic diversity and tolerance and combined with precision agriculture could increase food security in the Southeast.

  2. Effects of sulekang capsule in enhancement of resistance to radiation and regulating immunological function in mice

    International Nuclear Information System (INIS)

    Zhao Naikun; Zhou Ouliang; Du Weixia

    1990-01-01

    The effects of Sulekang capsule in enhancing the resistance to radiation and regulating the immunological function in mice were described. The results show that Sulekang capsule may lengthen the survival time (p 60 Co gamma rays. The experimental results of ANAE reaction show that the activety of T cells of normal or exposed mice may be enhanced by Sulekang capsule, which can control the decrease of both ANAE-positive cells and T cells in exposed mice. So it may enhance the immunological function on exposed animals

  3. Application of Sodium Silicate Enhances Cucumber Resistance to Fusarium Wilt and Alters Soil Microbial Communities

    Directory of Open Access Journals (Sweden)

    Xingang Zhou

    2018-05-01

    Full Text Available Exogenous silicates can enhance plant resistance to pathogens and change soil microbial communities. However, the relationship between changes in soil microbial communities and enhanced plant resistance remains unclear. Here, effects of exogenous sodium silicate on cucumber (Cucumis sativus L. seedling resistance to Fusarium wilt caused by the soil-borne pathogen Fusarium oxysporum f.sp. cucumerinum Owen (FOC were investigated by drenching soil with 2 mM sodium silicate. Soil bacterial and fungal community abundances and compositions were estimated by real-time PCR and high-throughput amplicon sequencing; then, feedback effects of changes in soil biota on cucumber seedling resistance to FOC were assessed. Moreover, effects of sodium silicate on the growth of FOC and Streptomyces DHV3-2, an antagonistic bacterium to FOC, were investigated both in vitro and in the soil environment. Results showed that exogenous sodium silicate enhanced cucumber seedling growth and resistance to FOC. In bare soil, sodium silicate increased bacterial and fungal community abundances and diversities. In cucumber-cultivated soil, sodium silicate increased bacterial community abundances, but decreased fungal community abundances and diversities. Sodium silicate also changed soil bacterial and fungal communality compositions, and especially, decreased the relative abundances of microbial taxa containing plant pathogens but increased these with plant-beneficial potentials. Moreover, sodium silicate increased the abundance of Streptomyces DHV3-2 in soil. Soil biota from cucumber-cultivated soil treated with sodium silicate decreased cucumber seedling Fusarium wilt disease index, and enhanced cucumber seedling growth and defense-related enzyme activities in roots. Sodium silicate at pH 9.85 inhibited FOC abundance in vitro, but did not affect FOC abundance in soil. Overall, our results suggested that, in cucumber-cultivated soil, sodium silicate increased cucumber seedling

  4. The identification of aluminium-resistance genes provides opportunities for enhancing crop production on acid soils.

    Science.gov (United States)

    Ryan, P R; Tyerman, S D; Sasaki, T; Furuichi, T; Yamamoto, Y; Zhang, W H; Delhaize, E

    2011-01-01

    Acid soils restrict plant production around the world. One of the major limitations to plant growth on acid soils is the prevalence of soluble aluminium (Al(3+)) ions which can inhibit root growth at micromolar concentrations. Species that show a natural resistance to Al(3+) toxicity perform better on acid soils. Our understanding of the physiology of Al(3+) resistance in important crop plants has increased greatly over the past 20 years, largely due to the application of genetics and molecular biology. Fourteen genes from seven different species are known to contribute to Al(3+) tolerance and resistance and several additional candidates have been identified. Some of these genes account for genotypic variation within species and others do not. One mechanism of resistance which has now been identified in a range of species relies on the efflux of organic anions such as malate and citrate from roots. The genes controlling this trait are members of the ALMT and MATE families which encode membrane proteins that facilitate organic anion efflux across the plasma membrane. Identification of these and other resistance genes provides opportunities for enhancing the Al(3+) resistance of plants by marker-assisted breeding and through biotechnology. Most attempts to enhance Al(3+) resistance in plants with genetic engineering have targeted genes that are induced by Al(3+) stress or that are likely to increase organic anion efflux. In the latter case, studies have either enhanced organic anion synthesis or increased organic anion transport across the plasma membrane. Recent developments in this area are summarized and the structure-function of the TaALMT1 protein from wheat is discussed.

  5. Enhanced transmission of drug-resistant parasites to mosquitoes following drug treatment in rodent malaria.

    Directory of Open Access Journals (Sweden)

    Andrew S Bell

    Full Text Available The evolution of drug resistant Plasmodium parasites is a major challenge to effective malaria control. In theory, competitive interactions between sensitive parasites and resistant parasites within infections are a major determinant of the rate at which parasite evolution undermines drug efficacy. Competitive suppression of resistant parasites in untreated hosts slows the spread of resistance; competitive release following treatment enhances it. Here we report that for the murine model Plasmodium chabaudi, co-infection with drug-sensitive parasites can prevent the transmission of initially rare resistant parasites to mosquitoes. Removal of drug-sensitive parasites following chemotherapy enabled resistant parasites to transmit to mosquitoes as successfully as sensitive parasites in the absence of treatment. We also show that the genetic composition of gametocyte populations in host venous blood accurately reflects the genetic composition of gametocytes taken up by mosquitoes. Our data demonstrate that, at least for this mouse model, aggressive chemotherapy leads to very effective transmission of highly resistant parasites that are present in an infection, the very parasites which undermine the long term efficacy of front-line drugs.

  6. Enterocin A mutants identified by saturation mutagenesis enhance potency towards vancomycin-resistant Enterococci.

    Science.gov (United States)

    McClintock, Maria K; Kaznessis, Yiannis N; Hackel, Benjamin J

    2016-02-01

    Vancomycin-resistant Enterococci infections are a significant clinical problem. One proposed solution is to use probiotics, such as lactic acid bacteria, to produce antimicrobial peptides at the site of infection. Enterocin A, a class 2a bacteriocin, exhibits inhibitory activity against E. faecium and E. faecalis, which account for 86% of vancomycin-resistant Enterococci infections. In this study, we aimed to engineer enterocin A mutants with enhanced potency within a lactic acid bacterial production system. Peptide mutants resulting from saturation mutagenesis at sites A24 and T27 were efficiently screened in a 96-well plate assay for inhibition of pathogen growth. Several mutants exhibit increased potency relative to wild-type enterocin A in both liquid- and solid-medium growth assays. In particular, A24P and T27G exhibit enhanced inhibition of multiple strains of E. faecium and E. faecalis, including clinically isolated vancomycin-resistant strains. A24P and T27G enhance killing of E. faecium 8 by 13 ± 3- and 18 ± 4-fold, respectively. The engineered enterocin A/lactic acid bacteria systems offer significant potential to combat antibiotic-resistant infections. © 2015 Wiley Periodicals, Inc.

  7. Enhanced anticancer activity and circumvention of resistance mechanisms by novel polymeric/ phospholipidic nanocarriers of doxorubicin.

    Science.gov (United States)

    Senkiv, Y; Riabtseva, A; Heffeter, P; Boiko, N; Kowol, C R; Jungwith, U; Shlyakhtina, Y; Garasevych, S G; Mitina, N; Berger, W; Zaichenko, A; Stoika, R

    2014-07-01

    Severe toxic side effects and drug resistance are the major limitations of doxorubicin (Dox), one of the most potent anticancer agents in clinical use. Nanocarrier preparations offer the opportunity to overcome these drawbacks, which is reflected in the clinical approval of two liposomal Dox preparations. Additionally, there are many attempts to enhance the activity of Dox against multi-drug resistant (MDR) cancer cells. However, most of these strategies resulted in the increased uptake of Dox in resistant cells, only, while it remained unchanged in chemo-sensitive cells. Here, we present a new polymeric-phospholipidic hybrid delivery system which distinctly enhanced the accumulation and activity of Dox in all tested cancer cell lines including several MDR cell models. Notably, the resistance levels against Dox were reduced from about 6-fold to about 2-fold. Moreover, the new nanocarriers were shown to rapidly (within 10 min) and effectively transport Dox into resistant as well as sensitive cancer cells. Consequently, treatment with the new Dox-containing nanocarriers resulted in effective cell cycle arrest in G2/M phase and ROS-induced cell death induction. Finally, the new nanocarriers were tested against NK/Ly lymphoma and L1210 leukemia cells in vivo. In both cell models, the nanoformulation of Dox resulted in 100% cured animals already at low concentrations (0.1 mg/kg), while free Dox solely extended survival time. This indicates that the incorporation of phospholipids into PEGylated polymeric nanocarriers is a promising strategy to enhance efficacy and reduce toxicity of Dox treatment against both sensitive and resistant cancer models in vitro and in vivo.

  8. ENHANCEMENT OF RESISTANCE TO OXIDATIVE DEGRADATION OF NATURAL RUBBER THROUGH LATEX DEGRADATION

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    A fully characterised natural rubber latex was subjected to mechanical degradation by stirring at intervals. The resistance to oxidative degradation of the different samples were studied by measuring the Plasticity retention indices (PRI).The results show that there is an enhancement of the PRI from 57% for the undegraded rubber to 79% for the one-hour degraded sample. Further degradation resulted in decrease of PRI as time of degradation increased. Therefore, the one-hour degraded sample is a special rubber with high oxidation resistance which is of great importance in engineering.

  9. Enhanced 2,4-D Metabolism in Two Resistant Papaver rhoeas Populations from Spain

    Directory of Open Access Journals (Sweden)

    Joel Torra

    2017-09-01

    Full Text Available Corn poppy (Papaver rhoeas, the most problematic broadleaf weed in winter cereals in Southern Europe, has developed resistance to the widely-used herbicide, 2,4-D. The first reported resistance mechanism in this species to 2,4-D was reduced translocation from treated leaves to the rest of the plant. However, the presence of other non-target site resistance (NTSR mechanisms has not been investigated up to date. Therefore, the main objective of this research was to reveal if enhanced 2,4-D metabolism is also present in two Spanish resistant (R populations to synthetic auxins. With this aim, HPLC experiments at two 2,4-D rates (600 and 2,400 g ai ha−1 were conducted to identify and quantify the metabolites produced and evaluate possible differences in 2,4-D degradation between resistant (R and susceptible (S plants. Secondarily, to determine the role of cytochrome P450 in the resistance response, dose-response experiments were performed using malathion as its inhibitor. Three populations were used: S, only 2,4-D R (R-703 and multiple R to 2,4-D and ALS inhibitors (R-213. HPLC studies indicated the presence of two hydroxy metabolites in these R populations in shoots and roots, which were not detected in S plants, at both rates. Therefore, enhanced metabolism becomes a new NTSR mechanism in these two P. rhoeas populations from Spain. Results from the dose-response experiments also showed that pre-treatment of R plants with the cytochrome P450 (P450 inhibitor malathion reversed the phenotype to 2,4-D from resistant to susceptible in both R populations. Therefore, it could be hypothesized that a malathion inhibited P450 is responsible of the formation of the hydroxy metabolites detected in the metabolism studies. This and previous research indicate that two resistant mechanisms to 2,4-D could be present in populations R-703 and R-213: reduced translocation and enhanced metabolism. Future experiments are required to confirm these hypotheses

  10. Hydroxyapatite/poly(epsilon-caprolactone) double coating on magnesium for enhanced corrosion resistance and coating flexibility.

    Science.gov (United States)

    Jo, Ji-Hoon; Li, Yuanlong; Kim, Sae-Mi; Kim, Hyoun-Ee; Koh, Young-Hag

    2013-11-01

    Hydroxyapatite was deposited on pure magnesium (Mg) with a flexible poly(ε-caprolactone) interlayer to reduce the corrosion rate of Mg and enhance coating flexibility. The poly(ε-caprolactone) interlayer was uniformly coated on Mg by a spraying method, followed by hydroxyapatite deposition on the poly(ε-caprolactone) using an aerosol deposition method. In scanning electron microscopy observations, inorganic/organic composite-like structure was observed between the hydroxyapatite and poly(ε-caprolactone) layers, resulting from the collisions of hydroxyapatite particles into the poly(ε-caprolactone) matrix at the initial stage of the aerosol deposition. The corrosion resistance of the coated Mg was examined using potentiodynamic polarization tests. The hydroxyapatite/poly(ε-caprolactone) double coating remarkably improved the corrosion resistance of Mg in Hank's solution. In the in vitro cell tests, the coated Mg showed better cell adhesion compared with the bare Mg due to the reduced corrosion rate and enhanced biocompatibility. The stability and flexibility of hydroxyapatite/poly(ε-caprolactone) double coating was investigated by scanning electron microscopy inspections after the coated Mg was deformed. The hydroxyapatite coating on the poly(ε-caprolactone) interlayer revealed enhanced coating stability and flexibility without cracking or delamination during bending and stretching compared with the hydroxyapatite single coating. These results demonstrated that the hydroxyapatite/poly(ε-caprolactone) double coating significantly improved the surface corrosion resistance of Mg and enhanced coating flexibility for use of Mg as a biodegradable implant.

  11. Improved Bilayer Resist System Using Contrast-Enhanced Lithography With Water-Soluble Photopolymer

    Science.gov (United States)

    Sasago, Masaru; Endo, Masayuki; Hirai, Yoshihiko; Ogawa, Kazufurni; Ishihara, Takeshi

    1986-07-01

    A new water-soluble contract enhanced material, WSP (Water-soluble Photopolymer), has been developed. The WSP is composed of a mainpolymer and a photobleachable reagents. The mainpolymer is a water-soluble polymer mixed with pullulan (refined through biotechnological process) and polyvinyl-pyrolidone (PVP). The photo-bleachable reagent is of a diazonium compound gorup. The introduction of the mainpolymer and photobleach-able reagent mixture has improved filmity, gas transparency, photobleaching characteristics and solubility in alkaline which are essential to the device fabrication. Submicron photoresist patterns are successfully fabricated by a simple sequence of photolithography process. The WSP layer has been applied to the bilayer resist system--deep-UV portable conformable masking (PCM)--that is not affected by VLSI's topography, and is able to fabricate highly accurate pattern. The aqueous developable layer, PMGI, with high organic solvent resistance is used in the bottom layer. Therefore, no interfacial mixing with conventional positive resist top layer is observed. Furthermore, deep-UV exposure method has been used for the KrF excimer laser optical system in order to increase high throughput. From the experiments, it has been confirmed that good resist transfer profile can be realized by the use of WSP, and that the submicron resist patterns with high aspect-ratio can be developed on the nonplaner wafer with steps of up to 41m by the combination of the WSP with the PCM system. By this technology, has been improved the weak point: variation in the line width due to the thickness of contrast-enhanced layer when the CEL technology is applied, and dependency of both the finished resist profile and the line-width accuracy on the thickness of the top layer resist when the PCM system is adopted.

  12. Does enhanced heat resistance of irradiated insects represent greater ability to adapt

    International Nuclear Information System (INIS)

    Ducoff, H.S.; MacDuff, R.A.

    1985-01-01

    Previous work from this lab demonstrated that irradiated flour beetles (Tribolium) develop resistance to oxygen with similar kinetics: greater sensitivity for about 1 week, increasing resistance over the next week, and resistance persisting for 3-6 months. This is in contrast to the rapid development of heat resistance in yeast exposed to UV or ionizing radiation and to rapid induction of heat-stress proteins in E. coli exposed to UV or nalidixic acid. The authors' early work did not distinguish between intrinsic heat resistance and enhanced ability to adapt. They tried to resolve this problem by comparing response of irradiated and of control beetles to challenge at 45 0 C with or without brief exposure to 41 0 C just prior to challenge. Mean lethal exposure time at 45 0 C was increased to about the same extent in both populations after 15 min at 41 0 C, suggesting that irradiation increases insectors' intrinsic resistance to stress rather than their ability to adapt

  13. Pavlovian conditioning enhances resistance to disruption of dogs performing an odor discrimination.

    Science.gov (United States)

    Hall, Nathaniel J; Smith, David W; Wynne, Clive D L

    2015-05-01

    Domestic dogs are used to aid in the detection of a variety of substances such as narcotics and explosives. Under real-world detection situations there are many variables that may disrupt the dog's performance. Prior research on behavioral momentum theory suggests that higher rates of reinforcement produce greater resistance to disruption, and that this is heavily influenced by the stimulus-reinforcer relationship. The present study tests the Pavlovian interpretation of resistance to change using dogs engaged in an odor discrimination task. Dogs were trained on two odor discriminations that alternated every six trials akin to a multiple schedule in which the reinforcement probability for a correct response was always 1. Dogs then received several sessions of either odor Pavlovian conditioning to the S+ of one odor discrimination (Pavlovian group) or explicitly unpaired exposure to the S+ of one odor discrimination (Unpaired group). The remaining odor discrimination pair for each dog always remained an unexposed control. Resistance to disruption was assessed under presession feeding, a food-odor disruptor condition, and extinction, with baseline sessions intervening between disruption conditions. Equivalent baseline detection rates were observed across experimental groups and odorant pairs. Under disruption conditions, Pavlovian conditioning led to enhanced resistance to disruption of detection performance compared to the unexposed control odor discrimination. Unpaired odor conditioning did not influence resistance to disruption. These results suggest that changes in Pavlovian contingencies are sufficient to influence resistance to change. © Society for the Experimental Analysis of Behavior.

  14. Nanotwin-enhanced fatigue resistance of ultrathin Ag films for flexible electronics applications

    Energy Technology Data Exchange (ETDEWEB)

    Wan, H.Y. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); School of Materials Science and Engineering, University of Science and Technology of China, Shenyang 110016 (China); Luo, X.M.; Li, X.; Liu, W. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, G.P., E-mail: gpzhang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2016-10-31

    Fatigue strength and cracking behavior of ultrathin Ag films on flexible polyimide substrates were investigated. The experimental results show that the enhanced fatigue strength of the 50 nm-thick Ag films not only is caused by the increase in the yield stress and the suppression of cyclic strain localization, but also results from the severe crack deflection induced by the formation of nanotwins, which delays the fatigue crack initiation and enhances the resistance to the fatigue crack growth. The fatigue cracking mechanism for the nanocrystalline metal films is evaluated.

  15. Mutants of Escherichia coli K-12 with enhanced resistance to ionizing radiation

    International Nuclear Information System (INIS)

    Verbenko, V.N.; Akhmedov, A.T.; Kalinin, V.L.

    1986-01-01

    By means of one-dimensional electrophoresis, it is shown that in radiation-resistant Gam 444 ad Gam 445 mutants of Escherichia coli K-12 high-molecular weight heat shock proteins are hyperproduced at 32-37 deg C and are induced more intensively during heat shock (in comparison to the parental) wild-tupe strain AB parallel 57). When the missense htp R15 mutation of the positive regulatory htpR gene for heat shock proteins was introduced by transduction into genome of the Gam 444 mutant, its enhanced radiation-resistance disappeared but could not be restored upon introduction of pKV3 plasmid bearing the htpR, gene. These data show that heat shock Protens are participating in the enhanced radioresistance of Gam mutants

  16. Chemically robust carbon nanotube–PTFE superhydrophobic thin films with enhanced ability of wear resistance

    Institute of Scientific and Technical Information of China (English)

    Kewei Wang; Pan Xiong; Xiuping Xu; Kan Wang; YanLong Li; Yufeng Zheng

    2017-01-01

    A chemically robust superhydrophobic nanocomposite thin film with enhanced wear resistance is prepared from a composite comprising polytetrafluoroethylene (PTFE) and carbon nanotubes. The superhydrophobic thin films with hierarchical structure are fabricated by spraying an environmentally friendly aqueous dispersion containing carbon nanotubes and PTFE resin on silicon wafer. Thin films with a contact angle of 154.1° ± 2° and a sliding angle less than 2° remain superhydrophobic after abrading over 500 times under a pressure of 50 g/cm2. The thin film is also extremely stable even under much stress conditions. To further the understanding of the enhancement of wear resistance, we investigated the formation of microsized structure and their effects. The growth of microbumps is caused by attracting solution droplet to the hydrophilic islands on hydrophobic surface.

  17. Research on test of alkali-resistant glass fibre enhanced seawater coral aggregate concrete

    Science.gov (United States)

    Liu, Leiyang; Wang, Xingquan

    2017-12-01

    It is proposed in the 13th five-year plan that reefs of the south China sea should be constructed. In the paper, an innovative thinking was proposed for the first time in order to realize local material acquisition in island construction and life dependence on sea, namely alkali-resistant glass fibre is mixed in coralaggregate concrete as reinforcing material. The glass fibre is characterized by low price, low hardness, good dispersibility and convenient construction. Reliable guarantee is provided for widely applying the material in future projects. In the paper, an orthogonal test method is firstly applied to determine the mix proportion of grade C50 coral aggregate concrete. Then, the design plan ofmix proportion of alkali-resistant glass fibre enhanced seawater coral aggregate concrete is determined. Finally, the influence law of alkali-resistant glass fibre dosageon tensile compressiveflexture strength of seawatercoralaggregate concrete is made clear.

  18. Companion cropping with potato onion enhances the disease resistance of tomato against Verticillium dahliae

    Directory of Open Access Journals (Sweden)

    Xuepeng eFu

    2015-09-01

    Full Text Available Intercropping could alleviate soil-borne diseases, however, few studies focused on the immunity of the host plant induced by the interspecific interactions. To test whether or not intercropping could enhance the disease resistance of host plant, we investigated the effect of companion cropping with potato onion on tomato Verticillium wilt caused by Verticillium dahliae (V. dahliae. To investigate the mechanisms, the root exudates were collected from tomato and potato onion which were grown together or separately, and were used to examine the antifungal activities against V. dahliae in vitro, respectively. Furthermore, RNA-seq was used to examine the expression pattern of genes related to disease resistance in tomato companied with potato onion compared to that in tomato grown alone, under the condition of infection with V. dahliae. The results showed that companion cropping with potato onion could alleviate the incidence and severity of tomato Verticillium wilt. The further studies revealed that the root exudates from tomato companied with potato onion significantly inhibited the mycelia growth and spore germination of V. dahliae. However, there were no significant effects on these two measurements for the root exudates from potato onion grown alone or from potato onion grown with tomato. RNA-seq data analysis showed the disease defense genes associated with pathogenesis-related proteins, biosynthesis of lignin, hormone metabolism and signal transduction were expressed much higher in the tomato companied with potato onion than those in the tomato grown alone, which indicated that these defense genes play important roles in tomato against V. dahliae infection, and meant that the disease resistance of tomato against V. dahliae was enhanced in the companion copping with potato onion. We proposed that companion cropping with potato onion could enhance the disease resistance of tomato against V. dahliae by regulating the expression of genes related

  19. Genetic diversity enhances the resistance of a seagrass ecosystem to disturbance

    OpenAIRE

    Hughes, A. R.; Stachowicz, John J

    2004-01-01

    Motivated by recent global reductions in biodiversity, empirical and theoretical research suggests that more species-rich systems exhibit enhanced productivity, nutrient cycling, or resistance to disturbance or invasion relative to systems with fewer species. In contrast, few data are available to assess the potential ecosystem-level importance of genetic diversity within species known to play a major functional role. Using a manipulative field experiment, we show that increasing genotypic di...

  20. Nano zinc phosphate coatings for enhanced corrosion resistance of mild steel

    International Nuclear Information System (INIS)

    Tamilselvi, M.; Kamaraj, P.; Arthanareeswari, M.; Devikala, S.

    2015-01-01

    Highlights: • Nano zinc phosphate coating on mild steel was developed. • Nano zinc phosphate coatings on mild steel showed enhanced corrosion resistance. • The nano ZnO increases the number of nucleating sites for phosphating. • Faster attainment of steady state during nano zinc phosphating. - Abstract: Nano crystalline zinc phosphate coatings were developed on mild steel surface using nano zinc oxide particles. The chemical composition and morphology of the coatings were analyzed by X-ray diffraction analysis (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). The particles size of the nano zinc phosphate coating developed was also characterized by TEM analysis. Potentiodynamic polarization and electrochemical impedance studies were carried out in 3.5% NaCl solution. Significant variations in the coating weight, morphology and corrosion resistance were observed as nano ZnO concentrations were varied from 0.25 to 2 g/L in the phosphating baths. The results showed that nano ZnO particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal ZnO particles in the phosphating baths). Better corrosion resistance was observed for coatings derived from phosphating bath containing 1.5 g/L nano ZnO. The activation effect brought about by the nano ZnO reduces the amount of accelerator (NaNO 2 ) required for phosphating

  1. The Enhancement of Mg Corrosion Resistance by Alloying Mn and Laser-Melting

    Directory of Open Access Journals (Sweden)

    Youwen Yang

    2016-03-01

    Full Text Available Mg has been considered a promising biomaterial for bone implants. However, the poor corrosion resistance has become its main undesirable property. In this study, both alloying Mn and laser-melting were applied to enhance the Mg corrosion resistance. The corrosion resistance, mechanical properties, and microstructure of rapid laser-melted Mg-xMn (x = 0–3 wt % alloys were investigated. The alloys were composed of dendrite grains, and the grains size decreased with increasing Mn. Moreover, Mn could dissolve and induce the crystal lattice distortion of the Mg matrix during the solidification process. Mn ranging from 0–2 wt % dissolved completely due to rapid laser solidification. As Mn contents further increased up to 3 wt %, a small amount of Mn was left undissolved. The compressive strength of Mg-Mn alloys increased first (up to 2 wt % and then decreased with increasing Mn, while the hardness increased continuously. The refinement of grains and the increase in corrosion potential both made contributions to the enhancement of Mg corrosion resistance.

  2. Transgenic Citrus Expressing an Arabidopsis NPR1 Gene Exhibit Enhanced Resistance against Huanglongbing (HLB; Citrus Greening).

    Science.gov (United States)

    Dutt, Manjul; Barthe, Gary; Irey, Michael; Grosser, Jude

    2015-01-01

    Commercial sweet orange cultivars lack resistance to Huanglongbing (HLB), a serious phloem limited bacterial disease that is usually fatal. In order to develop sustained disease resistance to HLB, transgenic sweet orange cultivars 'Hamlin' and 'Valencia' expressing an Arabidopsis thaliana NPR1 gene under the control of a constitutive CaMV 35S promoter or a phloem specific Arabidopsis SUC2 (AtSUC2) promoter were produced. Overexpression of AtNPR1 resulted in trees with normal phenotypes that exhibited enhanced resistance to HLB. Phloem specific expression of NPR1 was equally effective for enhancing disease resistance. Transgenic trees exhibited reduced diseased severity and a few lines remained disease-free even after 36 months of planting in a high-disease pressure field site. Expression of the NPR1 gene induced expression of several native genes involved in the plant defense signaling pathways. The AtNPR1 gene being plant derived can serve as a component for the development of an all plant T-DNA derived consumer friendly GM tree.

  3. Transgenic Citrus Expressing an Arabidopsis NPR1 Gene Exhibit Enhanced Resistance against Huanglongbing (HLB; Citrus Greening.

    Directory of Open Access Journals (Sweden)

    Manjul Dutt

    Full Text Available Commercial sweet orange cultivars lack resistance to Huanglongbing (HLB, a serious phloem limited bacterial disease that is usually fatal. In order to develop sustained disease resistance to HLB, transgenic sweet orange cultivars 'Hamlin' and 'Valencia' expressing an Arabidopsis thaliana NPR1 gene under the control of a constitutive CaMV 35S promoter or a phloem specific Arabidopsis SUC2 (AtSUC2 promoter were produced. Overexpression of AtNPR1 resulted in trees with normal phenotypes that exhibited enhanced resistance to HLB. Phloem specific expression of NPR1 was equally effective for enhancing disease resistance. Transgenic trees exhibited reduced diseased severity and a few lines remained disease-free even after 36 months of planting in a high-disease pressure field site. Expression of the NPR1 gene induced expression of several native genes involved in the plant defense signaling pathways. The AtNPR1 gene being plant derived can serve as a component for the development of an all plant T-DNA derived consumer friendly GM tree.

  4. Peculiarities of Enhancing Resistant Starch in Ruminants Using Chemical Methods: Opportunities and Challenges

    Directory of Open Access Journals (Sweden)

    Qendrim Zebeli

    2013-06-01

    Full Text Available High-producing ruminants are fed high amounts of cereal grains, at the expense of dietary fiber, to meet their high energy demands. Grains consist mainly of starch, which is easily degraded in the rumen by microbial glycosidases, providing energy for rapid growth of rumen microbes and short-chain fatty acids (SCFA as the main energy source for the host. Yet, low dietary fiber contents and the rapid accumulation of SCFA lead to rumen disorders in cattle. The chemical processing of grains has become increasingly important to confer their starch resistances against rumen microbial glycosidases, hence generating ruminally resistant starch (RRS. In ruminants, unlike monogastric species, the strategy of enhancing resistant starch is useful, not only in lowering the amount of carbohydrate substrates available for digestion in the upper gut sections, but also in enhancing the net hepatic glucose supply, which can be utilized by the host more efficiently than the hepatic gluconeogenesis of SCFA. The use of chemical methods to enhance the RRS of grains and the feeding of RRS face challenges in the practice; therefore, the present article attempts to summarize the most important achievements in the chemical processing methods used to generate RRS, and review advantages and challenges of feeding RRS to ruminants

  5. Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24.

    Science.gov (United States)

    Huang, Xuan; Wang, Jian; Du, Zhen; Zhang, Chen; Li, Lan; Xu, Ziqin

    2013-10-01

    Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T1 lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T1 plants. Resistance to stripe rust in transgenic T2 and T3 XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27-36 %) was recorded for transgenic T2 and T3 XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat.

  6. A nanometric cushion for enhancing scratch and wear resistance of hard films

    Directory of Open Access Journals (Sweden)

    Katya Gotlib-Vainshtein

    2014-07-01

    Full Text Available Scratch resistance and friction are core properties which define the tribological characteristics of materials. Attempts to optimize these quantities at solid surfaces are the subject of intense technological interest. The capability to modulate these surface properties while preserving both the bulk properties of the materials and a well-defined, constant chemical composition of the surface is particularly attractive. We report herein the use of a soft, flexible underlayer to control the scratch resistance of oxide surfaces. Titania films of several nm thickness are coated onto substrates of silicon, kapton, polycarbonate, and polydimethylsiloxane (PDMS. The scratch resistance measured by scanning force microscopy is found to be substrate dependent, diminishing in the order PDMS, kapton/polycarbonate, Si/SiO2. Furthermore, when PDMS is applied as an intermediate layer between a harder substrate and titania, marked improvement in the scratch resistance is achieved. This is shown by quantitative wear tests for silicon or kapton, by coating these substrates with PDMS which is subsequently capped by a titania layer, resulting in enhanced scratch/wear resistance. The physical basis of this effect is explored by means of Finite Element Analysis, and we suggest a model for friction reduction based on the "cushioning effect” of a soft intermediate layer.

  7. Silencing OsSLR1 enhances the resistance of rice to the brown planthopper Nilaparvata lugens.

    Science.gov (United States)

    Zhang, Jin; Luo, Ting; Wang, Wanwan; Cao, Tiantian; Li, Ran; Lou, Yonggen

    2017-10-01

    DELLA proteins, negative regulators of the gibberellin (GA) pathway, play important roles in plant growth, development and pathogen resistance by regulating multiple phytohormone signals. Yet, whether and how they regulate plant herbivore resistance remain unknown. We found that the expression of the rice DELLA gene OsSLR1 was down-regulated by an infestation of female adults of the brown planthopper (BPH) Nilaparvata lugens. On one hand, OsSLR1 positively regulated BPH-induced levels of two mitogen-activated protein kinase and four WRKY transcripts, and of jasmonic acid, ethylene and H 2 O 2 . On the other hand, silencing OsSLR1 enhanced constitutive levels of defence-related compounds, phenolic acids, lignin and cellulose, as well as the resistance of rice to BPH in the laboratory and in the field. The increased resistance in rice with silencing of OsSLR1 is probably due to impaired JA and ethylene pathways, and, at least in part, to the increased lignin level and mechanical hardness of rice leaf sheaths. Our findings illustrate that OsSLR1, acting as an early negative regulator, plays an important role in regulating the resistance of rice to BPH by activating appropriate defence-related signalling pathways and compounds. Moreover, our data also provide new insights into relationships between plant growth and defence. © 2017 John Wiley & Sons Ltd.

  8. Impairment of Cellulose Synthases Required for Arabidopsis Secondary Cell Wall Formation Enhances Disease Resistance[W

    Science.gov (United States)

    Hernández-Blanco, Camilo; Feng, Dong Xin; Hu, Jian; Sánchez-Vallet, Andrea; Deslandes, Laurent; Llorente, Francisco; Berrocal-Lobo, Marta; Keller, Harald; Barlet, Xavier; Sánchez-Rodríguez, Clara; Anderson, Lisa K.; Somerville, Shauna; Marco, Yves; Molina, Antonio

    2007-01-01

    Cellulose is synthesized by cellulose synthases (CESAs) contained in plasma membrane–localized complexes. In Arabidopsis thaliana, three types of CESA subunits (CESA4/IRREGULAR XYLEM5 [IRX5], CESA7/IRX3, and CESA8/IRX1) are required for secondary cell wall formation. We report that mutations in these proteins conferred enhanced resistance to the soil-borne bacterium Ralstonia solanacearum and the necrotrophic fungus Plectosphaerella cucumerina. By contrast, susceptibility to these pathogens was not altered in cell wall mutants of primary wall CESA subunits (CESA1, CESA3/ISOXABEN RESISTANT1 [IXR1], and CESA6/IXR2) or POWDERY MILDEW–RESISTANT5 (PMR5) and PMR6 genes. Double mutants indicated that irx-mediated resistance was independent of salicylic acid, ethylene, and jasmonate signaling. Comparative transcriptomic analyses identified a set of common irx upregulated genes, including a number of abscisic acid (ABA)–responsive, defense-related genes encoding antibiotic peptides and enzymes involved in the synthesis and activation of antimicrobial secondary metabolites. These data as well as the increased susceptibility of ABA mutants (abi1-1, abi2-1, and aba1-6) to R. solanacearum support a direct role of ABA in resistance to this pathogen. Our results also indicate that alteration of secondary cell wall integrity by inhibiting cellulose synthesis leads to specific activation of novel defense pathways that contribute to the generation of an antimicrobial-enriched environment hostile to pathogens. PMID:17351116

  9. A Lipid Transfer Protein Increases the Glutathione Content and Enhances Arabidopsis Resistance to a Trichothecene Mycotoxin.

    Directory of Open Access Journals (Sweden)

    John E McLaughlin

    Full Text Available Fusarium head blight (FHB or scab is one of the most important plant diseases worldwide, affecting wheat, barley and other small grains. Trichothecene mycotoxins such as deoxynivalenol (DON accumulate in the grain, presenting a food safety risk and health hazard to humans and animals. Despite considerable breeding efforts, highly resistant wheat or barley cultivars are not available. We screened an activation tagged Arabidopsis thaliana population for resistance to trichothecin (Tcin, a type B trichothecene in the same class as DON. Here we show that one of the resistant lines identified, trichothecene resistant 1 (trr1 contains a T-DNA insertion upstream of two nonspecific lipid transfer protein (nsLTP genes, AtLTP4.4 and AtLTP4.5. Expression of both nsLTP genes was induced in trr1 over 10-fold relative to wild type. Overexpression of AtLTP4.4 provided greater resistance to Tcin than AtLTP4.5 in Arabidopsis thaliana and in Saccharomyces cerevisiae relative to wild type or vector transformed lines, suggesting a conserved protection mechanism. Tcin treatment increased reactive oxygen species (ROS production in Arabidopsis and ROS stain was associated with the chloroplast, the cell wall and the apoplast. ROS levels were attenuated in Arabidopsis and in yeast overexpressing AtLTP4.4 relative to the controls. Exogenous addition of glutathione and other antioxidants enhanced resistance of Arabidopsis to Tcin while the addition of buthionine sulfoximine, an inhibitor of glutathione synthesis, increased sensitivity, suggesting that resistance was mediated by glutathione. Total glutathione content was significantly higher in Arabidopsis and in yeast overexpressing AtLTP4.4 relative to the controls, highlighting the importance of AtLTP4.4 in maintaining the redox state. These results demonstrate that trichothecenes cause ROS accumulation and overexpression of AtLTP4.4 protects against trichothecene-induced oxidative stress by increasing the glutathione

  10. 2-deoxy-D-glucose-induced metabolic stress enhances resistance to Listeria monocytogenes infection in mice

    Science.gov (United States)

    Miller, E. S.; Bates, R. A.; Koebel, D. A.; Fuchs, B. B.; Sonnenfeld, G.

    1998-01-01

    Exposure to different forms of psychological and physiological stress can elicit a host stress response, which alters normal parameters of neuroendocrine homeostasis. The present study evaluated the influence of the metabolic stressor 2-deoxy-D-glucose (2-DG; a glucose analog, which when administered to rodents, induces acute periods of metabolic stress) on the capacity of mice to resist infection with the facultative intracellular bacterial pathogen Listeria monocytogenes. Female BDF1 mice were injected with 2-DG (500 mg/kg b. wt.) once every 48 h prior to, concurrent with, or after the onset of a sublethal dose of virulent L. monocytogenes. Kinetics of bacterial growth in mice were not altered if 2-DG was applied concurrently or after the start of the infection. In contrast, mice exposed to 2-DG prior to infection demonstrated an enhanced resistance to the listeria challenge. The enhanced bacterial clearance in vivo could not be explained by 2-DG exerting a toxic effect on the listeria, based on the results of two experiments. First, 2-DG did not inhibit listeria replication in trypticase soy broth. Second, replication of L. monocytogenes was not inhibited in bone marrow-derived macrophage cultures exposed to 2-DG. Production of neopterin and lysozyme, indicators of macrophage activation, were enhanced following exposure to 2-DG, which correlated with the increased resistance to L. monocytogenes. These results support the contention that the host response to 2-DG-induced metabolic stress can influence the capacity of the immune system to resist infection by certain classes of microbial pathogens.

  11. Lifespan extension in the spontaneous dwarf rat and enhanced resistance to hyperoxia-induced mortality.

    Science.gov (United States)

    Sasaki, Toru; Tahara, Shoichi; Shinkai, Tadashi; Kuramoto, Kazunao; Matsumoto, Shigenobu; Yanabe, Makoto; Takagi, Shohei; Kondo, Hiroshi; Kaneko, Takao

    2013-05-01

    Lifespan extension has been demonstrated in dwarfism mouse models relative to their wild-type. The spontaneous dwarf rat (SDR) was isolated from a closed colony of Sprague-Dawley (SD) rats. Growth hormone deficiencies have been indicated to be responsible for dwarfism in SDR. Survival time, the markers of oxidative stress, antioxidant enzymes, and resistance to hyperoxia were compared between SDR and SD rats, to investigate whether SDR, a dwarfism rat model, also extends lifespan and has an enhanced resistance to oxidative stress. SDRs lived 38% longer than SD rats on average. This is the first report to show that dwarf rats exhibit lifespan extensions similar to Ames and Snell mice. Decreased 8-oxo-2'-deoxyguanosine (8-oxodG) content, a marker of oxidative DNA damage, indicated suppressed oxidative stress in the liver, kidney, and lung of SDRs. Increased glutathione peroxidase enzyme activity was consistent with decreased 8-oxodG content in the same tissues. The heart and brain showed a similar tendency, but this was not significant. However, the catalase and superoxide dismutase enzyme activities of SDRs were not different from those of SD rats in any tissue. This was not what the original null hypothesis predicted. SDRs had potent resistance to the toxicity associated with high O2 (85%) exposure. The mean survival time in SDRs was more than 147% that of SD rats with 168h O2 exposure. These results suggest that the enhanced resistance to oxidative stress of SDRs associated with enhanced hydrogen peroxide elimination may support its potential role in lifespan extension. Copyright © 2013 Elsevier Inc. All rights reserved.

  12. Salicylic acid confers enhanced resistance to Glomerella leaf spot in apple.

    Science.gov (United States)

    Zhang, Ying; Shi, Xiangpeng; Li, Baohua; Zhang, Qingming; Liang, Wenxing; Wang, Caixia

    2016-09-01

    Glomerella leaf spot (GLS) caused by Glomerella cingulata is a newly emergent disease that results in severe defoliation and fruit spots in apple. Currently, there are no effective means to control this disease except for the traditional fungicide sprays. Induced resistance by elicitors against pathogens infection is a widely accepted eco-friendly strategy. In the present study, we investigated whether exogenous application of salicylic acid (SA) could improve resistance to GLS in a highly susceptible apple cultivar (Malus domestica Borkh. cv. 'Gala') and the underlying mechanisms. The results showed that pretreatment with SA, at 0.1-1.0 mM, induced strong resistance against GLS in 'Gala' apple leaves, with SA treated leaves showing significant reduction in lesion numbers and disease index. Concurrent with the enhanced disease resistance, SA treatment markedly increased the total antioxidant capacity (T-AOC) and defence-related enzyme activities, including catalase (CAT), superoxide dismutase (SOD), peroxidase (POD), phenylalanine ammonia-lyase (PAL) and polyphenol oxidase (PPO). As expected, SA treatment also induced the expression levels of five pathogenesis-related (PR) genes including PR1, PR5, PR8, Chitinase and β-1,3-glucanase. Furthermore, the most pronounced and/or rapid increase was observed in leaves treated with SA and subsequently inoculated with G. cingulata compared to the treatment with SA or inoculation with the pathogen. Together, these results suggest that exogenous SA triggered increase in reactive oxygen species levels and the antioxidant system might be responsible for enhanced resistance against G. cingulata in 'Gala' apple leaves. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  13. A comparison of assisted, resisted, and common plyometric training modes to enhance sprint and agility performance.

    Science.gov (United States)

    Khodaei, Kazem; Mohammadi, Abbas; Badri, Neda

    2017-10-01

    The purpose of this study was to compare the effect of assisted, resisted and common plyometric training modes to enhance sprint and agility performance. Thirty active young males (age 20.67±1.12, height 174.83±4.69, weight 63.45±7.51) volunteered to participate in this study that 24 completed testing. The participants were randomly assigned into different groups: assisted, resisted and common plyometric exercises groups. Plyometric training involved three sessions per week for 4 weeks. The volume load of plyometric training modes was equated between the groups. The posttest was performed after 48 hours of the last training session. Between-group differences were analyzed with the ANCOVA and LSD post-hoc tests, and within-group differences were analyzed by a paired t-test. The findings of the present study indicated that 0-10-m, 20-30-m sprint time and the Illinois Agility Test time significantly decreased in the assisted and resisted plyometrics modes compared to the common plyometric training mode (P≤0.05). Also, the 0-10-m, 0-30-m sprint time and agility T-test time was significantly reduced with resisted plyometrics modes compared to the assisted and common plyometric modes (P≤0.05). There was no significant difference in the 10-20-m sprint time among the three plyometric training modes. The results of this study demonstrated that assisted and resisted plyometrics modes with elastic bands were effective methods to improve sprint and agility performance than common plyometric training in active males. Also, the resisted plyometrics mode was superior than the assisted plyometrics mode to improving sprint and agility tasks.

  14. Enhancement of antibiotic activity by efflux inhibitors against multidrug resistant Mycobacterium tuberculosis clinical isolates from Brazil

    Directory of Open Access Journals (Sweden)

    Tatiane eCoelho

    2015-04-01

    Full Text Available Drug resistant tuberculosis continues to increase and new approaches for its treatment are necessary. The identification of M. tuberculosis clinical isolates presenting efflux as part of their resistant phenotype has a major impact in tuberculosis treatment. In this work, we used a checkerboard procedure combined with the tetrazolium microplate-based assay (TEMA to study single combinations between antituberculosis drugs and efflux inhibitors (EIs against multidrug resistant M. tuberculosis clinical isolates using the fully susceptible strain H37Rv as reference. Efflux activity was studied on a real-time basis by a fluorometric method that uses ethidium bromide as efflux substrate. Quantification of efflux pump genes mRNA transcriptional levels were performed by RT-qPCR. The fractional inhibitory concentrations (FIC indicated synergistic activity for the interactions between isoniazid, rifampicin, amikacin, ofloxacin, and ethidium bromide plus the EIs verapamil, thioridazine and chlorpromazine. The FICs ranged from 0.25, indicating a four-fold reduction on the MICs, to 0.015, 64-fold reduction. The detection of active efflux by real-time fluorometry showed that all strains presented intrinsic efflux activity that contributes to the overall resistance which can be inhibited in the presence of the EIs. The quantification of the mRNA levels of the most important efflux pump genes on these strains shows that they are intrinsically predisposed to expel toxic compounds as the exposure to subinhibitory concentrations of antibiotics were not necessary to increase the pump mRNA levels when compared with the non-exposed counterpart. The results obtained in this study confirm that the intrinsic efflux activity contributes to the overall resistance in multidrug resistant clinical isolates of M. tuberculosis and that the inhibition of efflux pumps by the EIs can enhance the clinical effect of antibiotics that are their substrates.

  15. Sensitivity enhancement of chemically amplified resists and performance study using EUV interference lithography

    Science.gov (United States)

    Buitrago, Elizabeth; Nagahara, Seiji; Yildirim, Oktay; Nakagawa, Hisashi; Tagawa, Seiichi; Meeuwissen, Marieke; Nagai, Tomoki; Naruoka, Takehiko; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin

    2016-03-01

    Extreme ultraviolet lithography (EUVL, λ = 13.5 nm) is the most promising candidate to manufacture electronic devices for future technology nodes in the semiconductor industry. Nonetheless, EUVL still faces many technological challenges as it moves toward high-volume manufacturing (HVM). A key bottleneck from the tool design and performance point of view has been the development of an efficient, high power EUV light source for high throughput production. Consequently, there has been extensive research on different methodologies to enhance EUV resist sensitivity. Resist performance is measured in terms of its ultimate printing resolution, line width roughness (LWR), sensitivity (S or best energy BE) and exposure latitude (EL). However, there are well-known fundamental trade-off relationships (LRS trade-off) among these parameters for chemically amplified resists (CARs). Here we present early proof-of-principle results for a multi-exposure lithography process that has the potential for high sensitivity enhancement without compromising other important performance characteristics by the use of a Photosensitized Chemically Amplified Resist (PSCAR). With this method, we seek to increase the sensitivity by combining a first EUV pattern exposure with a second UV flood exposure (λ = 365 nm) and the use of a PSCAR. In addition, we have evaluated over 50 different state-of-the-art EUV CARs. Among these, we have identified several promising candidates that simultaneously meet sensitivity, LWR and EL high performance requirements with the aim of resolving line space (L/S) features for the 7 and 5 nm logic node (16 nm and 13 nm half-pitch HP, respectively) for HVM. Several CARs were additionally found to be well resolved down to 12 nm and 11 nm HP with minimal pattern collapse and bridging, a remarkable feat for CARs. Finally, the performance of two negative tone state-of-the-art alternative resist platforms previously investigated was compared to the CAR performance at and

  16. Evaluation of Radiation Response and Gold Nanoparticle Enhancement in Drug-Resistant Pancreatic Cancer Cells

    Science.gov (United States)

    Abourabia, Assya

    Pancreatic cancer is a major cause of cancer-related death worldwide after lung cancer and colorectal cancer Pancreatic treatment modalities consist of surgery, chemotherapy, and radiation therapy or combination of these therapies. These modalities are good to some extents but they do have some limitations. For example, during the chemotherapy, tumor cells can develop some escape mechanisms and become chemoresistant to protect themselves against the chemo drugs and pass on theses escape mechanisms to their offspring, despite the treatment given. Cancer Cells can become chemoresistant by many mechanisms, for example, decreased drug influx mechanisms, decreased of drug transport molecules, decreased drug activation, altered drug metabolism that diminishes the capacity of cytotoxic drugs, and enhanced repair of DNA damage. Given that some of these chemoresistance mechanisms may impact sensitivity to radiation. Therefore, there is a strong need for a new alternative treatment option to amplify the therapeutic efficacy of radiotherapy and eventually increase the overall efficacy of cancer treatment. Nano-radiation therapy is an emerging and promising modality aims to enhance the therapeutic efficacy of radiotherapy through the use of radiosensitizing nanoparticles. The primary goal of using GNP-enhanced radiation is that GNPs are potent radiosensitizer agents that sensitize the tumor cells to radiation, and these agents promote generation of the free radicals produced by Photo- and Auger- electrons emission at the molecular level which can enhance the effectiveness of radiation-induced cancer cell death. The main aim of this research is to analyze and compare the response to radiation of pancreatic cancer cells, PANC-1, and PANC-1 cells that are resistant to oxaliplatin, PANC-1/OR, and investigate the radiation dose enhancement effect attributable to GNP when irradiating the cells with low-energy (220 kVp) beam at various doses. Based on evidence from the existing

  17. Emodin enhances the chemosensitivity of endometrial cancer by inhibiting ROS-mediated Cisplatin-resistance.

    Science.gov (United States)

    Ding, Ning; Zhang, Hong; Su, Shan; Ding, Yumei; Yu, Xiaohui; Tang, Yujie; Wang, Qingfang; Liu, Peishu

    2017-12-18

    Background Endometrial cancer is a common cause of death in gynecological malignancies. Cisplatin is a clinically chemotherapeutic agent. However, drug-resistance is the primary cause of treatment failure. Objective Emodin is commonly used clinically to increase the sensitivity of chemotherapeutic agents, yet whether Emodin promotes the role of Cisplatin in the treatment of endometrial cancer has not been studied. Method CCK-8 kit was utilized to determine the growth of two endometrial cancer cell lines, Ishikawa and HEC-IB. The apoptosis level of Ishikawa and HEC-IB cells was detected by Annexin V / propidium iodide double-staining assay. ROS level was detected by DCFH-DA and NADPH oxidase expression. Expressions of drug-resistant genes were examined by real-time PCR and Western blotting. Results Emodin combined with Cisplatin reduced cell growth and increased the apoptosis of endometrial cancer cells. Co-treatment of Emodin and Cisplatin increased chemosensitivity by inhibiting the expression of drug-resistant genes through reducing the ROS levels in endometrial cancer cells. In an endometrial cancer xenograft murine model, the tumor size was reduced and animal survival time was increased by co-treatment of Emodin and Cisplatin. Conclusion This study demonstrates that Emodin enhances the chemosensitivity of Cisplatin on endometrial cancer by inhibiting ROS-mediated expression of drug-resistance genes. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  18. Improving the packing density of calcium phosphate coating on a magnesium alloy for enhanced degradation resistance.

    Science.gov (United States)

    Kannan, M Bobby

    2013-05-01

    In this study, an attempt was made to improve the packing density of calcium phosphate (CaP) coating on a magnesium alloy by tailoring the coating solution for enhanced degradation resistance of the alloy for implant applications. An organic solvent, ethanol, was added to the coating solution to decrease the conductivity of the coating solution so that hydrogen bubble formation/bursting reduces during the CaP coating process. Experimental results confirmed that ethanol addition to the coating solution reduces the conductivity of the solution and also decreases the hydrogen evolution/bubble bursting. In vitro electrochemical experiments, that is, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization showed that CaP coating produced in 30% (v/v) ethanol containing coating solution (3E) exhibits significantly higher degradation resistance (i.e., ~50% higher polarization resistance and ~60% lower corrosion current) than the aqueous solution coating. Scanning electron microscope (SEM) analysis of the coatings revealed that the packing of 3E coating was denser than that of aqueous coating, which can be attributed to the lower hydrogen evolution in the former than in the latter. Further increase in the ethanol content in the coating solution was not beneficial; in fact, the coating produced in 70% (v/v) ethanol containing solution (7E) showed degradation resistance much inferior to that of the aqueous coating, which is due to low thickness of 7E coating. Copyright © 2012 Wiley Periodicals, Inc.

  19. Transgenic expression of lactoferrin imparts enhanced resistance to head blight of wheat caused by Fusarium graminearum.

    Science.gov (United States)

    Han, Jigang; Lakshman, Dilip K; Galvez, Leny C; Mitra, Sharmila; Baenziger, Peter Stephen; Mitra, Amitava

    2012-03-09

    The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Using the tools of plant genetic engineering, a broad-spectrum antimicrobial gene was tested for resistance against head blight caused by Fusarium graminearum Schwabe, a devastating disease of wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) that reduces both grain yield and quality. A construct containing a bovine lactoferrin cDNA was used to transform wheat using an Agrobacterium-mediated DNA transfer system to express this antimicrobial protein in transgenic wheat. Transformants were analyzed by Northern and Western blots to determine lactoferrin gene expression levels and were inoculated with the head blight disease fungus F. graminearum. Transgenic wheat showed a significant reduction of disease incidence caused by F. graminearum compared to control wheat plants. The level of resistance in the highly susceptible wheat cultivar Bobwhite was significantly higher in transgenic plants compared to control Bobwhite and two untransformed commercial wheat cultivars, susceptible Wheaton and tolerant ND 2710. Quantification of the expressed lactoferrin protein by ELISA in transgenic wheat indicated a positive correlation between the lactoferrin gene expression levels and the levels of disease resistance. Introgression of the lactoferrin gene into elite commercial wheat, barley and other susceptible cereals may enhance resistance to F. graminearum.

  20. Host-Induced Silencing of Pathogenicity Genes Enhances Resistance to Fusarium oxysporum Wilt in Tomato.

    Science.gov (United States)

    Bharti, Poonam; Jyoti, Poonam; Kapoor, Priya; Sharma, Vandana; Shanmugam, V; Yadav, Sudesh Kumar

    2017-08-01

    This study presents a novel approach of controlling vascular wilt in tomato by RNAi expression directed to pathogenicity genes of Fusarium oxysporum f. sp. lycopersici. Vascular wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici leads to qualitative and quantitative loss of the crop. Limitation in the existing control measures necessitates the development of alternative strategies to increase resistance in the plants against pathogens. Recent findings paved way to RNAi, as a promising method for silencing of pathogenicity genes in fungus and provided effective resistance against fungal pathogens. Here, two important pathogenicity genes FOW2, a Zn(II)2Cys6 family putative transcription regulator, and chsV, a putative myosin motor and a chitin synthase domain, were used for host-induced gene silencing through hairpinRNA cassettes of these genes against Fusarium oxysporum f. sp. lycopersici. HairpinRNAs were assembled in appropriate binary vectors and transformed into tomato plant targeting FOW2 and chsV genes, for two highly pathogenic strains of Fusarium oxysporum viz. TOFOL-IHBT and TOFOL-IVRI. Transgenic tomatoes were analyzed for possible attainment of resistance in transgenic lines against fungal infection. Eight transgenic lines expressing hairpinRNA cassettes showed trivial disease symptoms after 6-8 weeks of infection. Hence, the host-induced posttranscriptional gene silencing of pathogenicity genes in transgenic tomato plants has enhanced their resistance to vascular wilt disease caused by Fusarium oxysporum.

  1. Air-Impregnated Nanoporous Anodic Aluminum Oxide Layers for Enhancing the Corrosion Resistance of Aluminum.

    Science.gov (United States)

    Jeong, Chanyoung; Lee, Junghoon; Sheppard, Keith; Choi, Chang-Hwan

    2015-10-13

    Nanoporous anodic aluminum oxide layers were fabricated on aluminum substrates with systematically varied pore diameters (20-80 nm) and oxide thicknesses (150-500 nm) by controlling the anodizing voltage and time and subsequent pore-widening process conditions. The porous nanostructures were then coated with a thin (only a couple of nanometers thick) Teflon film to make the surface hydrophobic and trap air in the pores. The corrosion resistance of the aluminum substrate was evaluated by a potentiodynamic polarization measurement in 3.5 wt % NaCl solution (saltwater). Results showed that the hydrophobic nanoporous anodic aluminum oxide layer significantly enhanced the corrosion resistance of the aluminum substrate compared to a hydrophilic oxide layer of the same nanostructures, to bare (nonanodized) aluminum with only a natural oxide layer on top, and to the latter coated with a thin Teflon film. The hydrophobic nanoporous anodic aluminum oxide layer with the largest pore diameter and the thickest oxide layer (i.e., the maximized air fraction) resulted in the best corrosion resistance with a corrosion inhibition efficiency of up to 99% for up to 7 days. The results demonstrate that the air impregnating the hydrophobic nanopores can effectively inhibit the penetration of corrosive media into the pores, leading to a significant improvement in corrosion resistance.

  2. Transgenic expression of lactoferrin imparts enhanced resistance to head blight of wheat caused by Fusarium graminearum

    Directory of Open Access Journals (Sweden)

    Han Jigang

    2012-03-01

    Full Text Available Abstract Background The development of plant gene transfer systems has allowed for the introgression of alien genes into plant genomes for novel disease control strategies, thus providing a mechanism for broadening the genetic resources available to plant breeders. Using the tools of plant genetic engineering, a broad-spectrum antimicrobial gene was tested for resistance against head blight caused by Fusarium graminearum Schwabe, a devastating disease of wheat (Triticum aestivum L. and barley (Hordeum vulgare L. that reduces both grain yield and quality. Results A construct containing a bovine lactoferrin cDNA was used to transform wheat using an Agrobacterium-mediated DNA transfer system to express this antimicrobial protein in transgenic wheat. Transformants were analyzed by Northern and Western blots to determine lactoferrin gene expression levels and were inoculated with the head blight disease fungus F. graminearum. Transgenic wheat showed a significant reduction of disease incidence caused by F. graminearum compared to control wheat plants. The level of resistance in the highly susceptible wheat cultivar Bobwhite was significantly higher in transgenic plants compared to control Bobwhite and two untransformed commercial wheat cultivars, susceptible Wheaton and tolerant ND 2710. Quantification of the expressed lactoferrin protein by ELISA in transgenic wheat indicated a positive correlation between the lactoferrin gene expression levels and the levels of disease resistance. Conclusions Introgression of the lactoferrin gene into elite commercial wheat, barley and other susceptible cereals may enhance resistance to F. graminearum.

  3. Nanocontainer-Enhanced Self-Healing for Corrosion-Resistant Ni Coating on Mg Alloy.

    Science.gov (United States)

    Xie, Zhi-Hui; Li, Dan; Skeete, Zakiya; Sharma, Anju; Zhong, Chuan-Jian

    2017-10-18

    The ability to manipulate the functionalization of Ni coating is of great importance in improving the corrosion resistance of magnesium (Mg) alloy for many industrial applications. In the present work, MCM-41 type mesoporous silica nanocontainers (MSNs) loaded with corrosion inhibitor (NaF) were synthesized and employed as smart reinforcements to enhance the integrity and corrosion inhibition of the Ni coating. The incorporation of the F-loaded MSNs (F@MSNs) to enhance the corrosion resistant capacity of a metallic coating is reported for the first time. The mesoporous structures of the as-prepared MSNs and F@MSNs were confirmed by transmission electron microscopy (TEM), small angle X-rays scattering (SAXS), and N 2 adsorption-desorption isotherms. The X-ray photoelectron spectroscopy (XPS) data demonstrated the successful immobilization of fluoride ion on the MSNs and formation of a magnesium fluoride (MgF 2 ) protective film at the corrosion sites of the Mg alloy upon soaking in a F@MSNs-containing NaCl solution. The results from potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) for both bare Mg alloy and Ni coatings with and without F@MSNs have revealed a clear decrease in corrosion rate in a corrosive solution for a long-time immersion due to the introduction of F@MSNs. These findings open new opportunities in the exploration of self-healing metallic coatings for highly enhanced anticorrosion protection of Mg alloy.

  4. Hardness enhancement and oxidation resistance of nanocrystalline TiN/Mo xC multilayer films

    International Nuclear Information System (INIS)

    Liu, Q.; Wang, X.P.; Liang, F.J.; Wang, J.X.; Fang, Q.F.

    2006-01-01

    In this paper the influence of the layer's microstructure on the hardness enhancement in multilayer nanocrystalline films and the oxidation resistance are studied. The TiN/Mo x C multilayer films at different modulation period, and Mo x C and TiN monolayer films were deposited on the (0 0 1) silicon wafers and molybdenum sheets by rf and dc magnetron sputtering. The monolayer TiN films with a thickness of about 2 μm are of pure face-center cubic TiN phase, while the monolayer Mo x C films consist of two phases, one of which is body-center cubic Mo and the other is hexagonal Mo 2 C as determined by XRD. The coarse columnar grains of about 200 nm in the monolayer TiN films become much smaller or disappear in the multilayer films. The hardness enhancement of the multilayer films takes place at the modulation period of 320 nm, which can reach to 26 GPa and is much higher than the values of Mo x C and TiN monolayer films. This enhancement in hardness can be explained as the decrease in the size and/or disappearance of columnar grains in the TiN layer. The Young's modulus in the temperature range from 100 to 400 deg. C increases with decreasing modulation period. It is found that about 100 nm thick TiN films can increase largely the oxidation resistance of Mo x C films

  5. Short-term stress enhances cellular immunity and increases early resistance to squamous cell carcinoma.

    Science.gov (United States)

    Dhabhar, Firdaus S; Saul, Alison N; Daugherty, Christine; Holmes, Tyson H; Bouley, Donna M; Oberyszyn, Tatiana M

    2010-01-01

    In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposure would enhance protective immunity and increase resistance to SCC. Control and short-term stress groups were treated identically except that the short-term stress group was restrained (2.5h) before each of nine UV-exposure sessions (minimum erythemal dose, 3-times/week) during weeks 4-6 of the 10-week UV exposure protocol. Tumors were measured weekly, and tissue collected at weeks 7, 20, and 32. Chemokine and cytokine gene expression was quantified by real-time PCR, and CD4+ and CD8+ T cells by flow cytometry and immunohistochemistry. Compared to controls, the short-term stress group showed greater cutaneous T-cell attracting chemokine (CTACK)/CCL27, RANTES, IL-12, and IFN-gamma gene expression at weeks 7, 20, and 32, higher skin infiltrating T cell numbers (weeks 7 and 20), lower tumor incidence (weeks 11-20) and fewer tumors (weeks 11-26). These results suggest that activation of short-term stress physiology increased chemokine expression and T cell trafficking and/or function during/following UV exposure, and enhanced Type 1 cytokine-driven cell-mediated immunity that is crucial for resistance to SCC. Therefore, the physiological fight-or-flight stress response and its adjuvant-like immuno-enhancing effects, may provide a novel and important mechanism for enhancing immune system mediated tumor-detection/elimination that merits further investigation.

  6. Enhanced corrosion resistance of strontium hydroxyapatite coating on electron beam treated surgical grade stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Gopi, D., E-mail: dhanaraj_gopi@yahoo.com [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Rajeswari, D. [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India); Ramya, S. [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Sekar, M. [Department of Chemistry, Periyar University, Salem 636 011, Tamilnadu (India); Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India); R, Pramod; Dwivedi, Jishnu [Industrial and Medical Accelerator Section, Raja Ramanna Centre for Advanced Technology, Indore 452 013, Madhya Pradesh (India); Kavitha, L., E-mail: louiskavitha@yahoo.co.in [Centre for Nanoscience and Nanotechnology, Periyar University, Salem 636 011, Tamilnadu (India); Department of Physics, Periyar University, Salem 636 011, Tamilnadu (India); Ramaseshan, R. [Thin film and Coatings Section, Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, Tamilnadu (India)

    2013-12-01

    The surface of 316L stainless steel (316L SS) is irradiated by high energy low current DC electron beam (HELCDEB) with energy of 500 keV and beam current of 1.5 mA followed by the electrodeposition of strontium hydroxyapatite (Sr-HAp) to enhance its corrosion resistance in physiological fluid. The coatings were characterised by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and High resolution scanning electron microscopy (HRSEM). The Sr-HAp coating on HELCDEB treated 316L SS exhibits micro-flower structure. Electrochemical results show that the Sr-HAp coating on HELCDEB treated 316L SS possesses maximum corrosion resistance in Ringer's solution.

  7. Enhanced corrosion resistance of strontium hydroxyapatite coating on electron beam treated surgical grade stainless steel

    Science.gov (United States)

    Gopi, D.; Rajeswari, D.; Ramya, S.; Sekar, M.; R, Pramod; Dwivedi, Jishnu; Kavitha, L.; Ramaseshan, R.

    2013-12-01

    The surface of 316L stainless steel (316L SS) is irradiated by high energy low current DC electron beam (HELCDEB) with energy of 500 keV and beam current of 1.5 mA followed by the electrodeposition of strontium hydroxyapatite (Sr-HAp) to enhance its corrosion resistance in physiological fluid. The coatings were characterised by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and High resolution scanning electron microscopy (HRSEM). The Sr-HAp coating on HELCDEB treated 316L SS exhibits micro-flower structure. Electrochemical results show that the Sr-HAp coating on HELCDEB treated 316L SS possesses maximum corrosion resistance in Ringer's solution.

  8. Enhanced satellite cell proliferation with resistance training in elderly men and women

    DEFF Research Database (Denmark)

    Mackey, Abigail; Esmarck, B; Kadi, F

    2007-01-01

    In addition to the well-documented loss of muscle mass and strength associated with aging, there is evidence for the attenuating effects of aging on the number of satellite cells in human skeletal muscle. The aim of this study was to investigate the response of satellite cells in elderly men...... and women to 12 weeks of resistance training. Biopsies were collected from the m. vastus lateralis of 13 healthy elderly men and 16 healthy elderly women (mean age 76+/-SD 3 years) before and after the training period. Satellite cells were visualized by immunohistochemical staining of muscle cross.......15+/-0.06; mean+/-SD) and females (from 0.11+/-0.04 to 0.13+/-0.05). These results suggest that 12 weeks of resistance training is effective in enhancing the satellite cell pool in skeletal muscle in the elderly....

  9. Ester-free Thiol-X Resins: New Materials with Enhanced Mechanical Behavior and Solvent Resistance.

    Science.gov (United States)

    Podgórski, Maciej; Becka, Eftalda; Chatani, Shunsuke; Claudino, Mauro; Bowman, Christopher N

    A series of thiol-Michael and radical thiol-ene network polymers were successfully prepared from ester-free as well as ester-containing monomer formulations. Polymerization reaction rates, dynamic mechanical analysis, and solvent resistance experiments were performed and compared between compositions with varied ester loading. The incorporation of ester-free alkyl thiol, vinyl sulfone and allylic monomers significantly improved the mechanical properties when compared with commercial, mercaptopropionate-based thiol-ene or thiol-Michael networks. For polymers with no hydrolytically degradable esters, glass transition temperatures (T g 's) as high as 100 °C were achieved. Importantly, solvent resistance tests demonstrated enhanced stability of ester-free formulations over PETMP-based polymers, especially in concentrated basic solutions. Kinetic analysis showed that glassy step-growth polymers are readily formed at ambient conditions with conversions reaching 80% and higher.

  10. Experimental Study of Laser - enhanced 5A03 Aluminum Alloy and Its Stress Corrosion Resistance

    Science.gov (United States)

    Wang, Guicheng; Chen, Jing; Pang, Tao

    2018-02-01

    Based on the study of improving the stress corrosion resistance of 5A03 aluminum alloy for ship, this paper mainly studied the tensile test, surface morphology and residual stress under laser shock, high temperature and stress corrosion. It is found that the residual compressive stress and the grain refinement on the surface of the material during the heat strengthening process increase the breaking strength of the sample in the stress corrosion environment. Appropriate high temperature maintenance helps to enhance the effect of deformation strengthening. In the 300°C environment insulation, due to recrystallization of the material, the performance decreased significantly. This study provides an experimental basis for effectively improving the stress corrosion resistance of 5A03 aluminum alloy.

  11. Speech Enhancement by Multichannel Crosstalk Resistant ANC and Improved Spectrum Subtraction

    Directory of Open Access Journals (Sweden)

    Zeng Qingning

    2006-01-01

    Full Text Available A scheme combining multichannel crosstalk resistant adaptive noise cancellation (MCRANC algorithm and improved spectrum subtraction (ISS algorithm is presented to enhance noise carrying speech signals. The scheme would permit locating the microphones in close proximity by virtue of using MCRANC which has the capability of removing the crosstalk effect. MCRANC would also permit canceling out nonstationary noise and making the residual noise more stationary for further treatment by ISS algorithm. Experimental results have indicated that this scheme outperforms many commonly used techniques in the sense of SNR improvement and music effect reduction which is an inevitable byproduct of the spectrum subtraction algorithm.

  12. Sensitivity enhancement of chemically amplified resists and performance study using extreme ultraviolet interference lithography

    Science.gov (United States)

    Buitrago, Elizabeth; Nagahara, Seiji; Yildirim, Oktay; Nakagawa, Hisashi; Tagawa, Seiichi; Meeuwissen, Marieke; Nagai, Tomoki; Naruoka, Takehiko; Verspaget, Coen; Hoefnagels, Rik; Rispens, Gijsbert; Shiraishi, Gosuke; Terashita, Yuichi; Minekawa, Yukie; Yoshihara, Kosuke; Oshima, Akihiro; Vockenhuber, Michaela; Ekinci, Yasin

    2016-07-01

    Extreme ultraviolet lithography (EUVL, λ=13.5 nm) is the most promising candidate to manufacture electronic devices for future technology nodes in the semiconductor industry. Nonetheless, EUVL still faces many technological challenges as it moves toward high-volume manufacturing (HVM). A key bottleneck from the tool design and performance point of view has been the development of an efficient, high-power EUV light source for high throughput production. Consequently, there has been extensive research on different methodologies to enhance EUV resist sensitivity. Resist performance is measured in terms of its ultimate printing resolution, line width roughness (LWR), sensitivity [S or best energy (BE)], and exposure latitude (EL). However, there are well-known fundamental trade-off relationships (line width roughness, resolution and sensitivity trade-off) among these parameters for chemically amplified resists (CARs). We present early proof-of-principle results for a multiexposure lithography process that has the potential for high sensitivity enhancement without compromising other important performance characteristics by the use of a "Photosensitized Chemically Amplified Resist™" (PSCAR™). With this method, we seek to increase the sensitivity by combining a first EUV pattern exposure with a second UV-flood exposure (λ=365 nm) and the use of a PSCAR. In addition, we have evaluated over 50 different state-of-the-art EUV CARs. Among these, we have identified several promising candidates that simultaneously meet sensitivity, LWR, and EL high-performance requirements with the aim of resolving line space (L/S) features for the 7- and 5-nm logic node [16- and 13-nm half-pitch (HP), respectively] for HVM. Several CARs were additionally found to be well resolved down to 12- and 11-nm HP with minimal pattern collapse and bridging, a remarkable feat for CARs. Finally, the performance of two negative tone state-of-the-art alternative resist platforms previously investigated

  13. Overexpressing CYP71Z2 enhances resistance to bacterial blight by suppressing auxin biosynthesis in rice.

    Directory of Open Access Journals (Sweden)

    Wenqi Li

    Full Text Available The hormone auxin plays an important role not only in the growth and development of rice, but also in its defense responses. We've previously shown that the P450 gene CYP71Z2 enhances disease resistance to pathogens through regulation of phytoalexin biosynthesis in rice, though it remains unclear if auxin is involved in this process or not.The expression of CYP71Z2 was induced by Xanthomonas oryzae pv. oryzae (Xoo inoculation was analyzed by qRT-PCR, with GUS histochemical staining showing that CYP71Z2 expression was limited to roots, blades and nodes. Overexpression of CYP71Z2 in rice durably and stably increased resistance to Xoo, though no significant difference in disease resistance was detected between CYP71Z2-RNA interference (RNAi rice and wild-type. Moreover, IAA concentration was determined using the HPLC/electrospray ionization/tandem mass spectrometry system. The accumulation of IAA was significantly reduced in CYP71Z2-overexpressing rice regardless of whether plants were inoculated or not, whereas it was unaffected in CYP71Z2-RNAi rice. Furthermore, the expression of genes related to IAA, expansin and SA/JA signaling pathways was suppressed in CYP71Z2-overexpressing rice with or without inoculation.These results suggest that CYP71Z2-mediated resistance to Xoo may be via suppression of IAA signaling in rice. Our studies also provide comprehensive insight into molecular mechanism of resistance to Xoo mediated by IAA in rice. Moreover, an available approach for understanding the P450 gene functions in interaction between rice and pathogens has been provided.

  14. Silencing of copine genes confers common wheat enhanced resistance to powdery mildew.

    Science.gov (United States)

    Zou, Baohong; Ding, Yuan; Liu, He; Hua, Jian

    2018-06-01

    Powdery mildew, caused by the biotrophic fungal pathogen Blumeria graminis f. sp. tritici (Bgt), is a major threat to the production of wheat (Triticum aestivum). It is of great importance to identify new resistance genes for the generation of Bgt-resistant or Bgt-tolerant wheat varieties. Here, we show that the wheat copine genes TaBON1 and TaBON3 negatively regulate wheat disease resistance to Bgt. Two copies of TaBON1 and three copies of TaBON3, located on chromosomes 6AS, 6BL, 1AL, 1BL and 1DL, respectively, were identified from the current common wheat genome sequences. The expression of TaBON1 and TaBON3 is responsive to both pathogen infection and temperature changes. Knocking down of TaBON1 or TaBON3 by virus-induced gene silencing (VIGS) induces the up-regulation of defence responses in wheat. These TaBON1- or TaBON3-silenced plants exhibit enhanced wheat disease resistance to Bgt, accompanied by greater accumulation of hydrogen peroxide and heightened cell death. In addition, high temperature has little effect on the up-regulation of defence response genes conferred by the silencing of TaBON1 or TaBON3. Our study shows a conserved function of plant copine genes in plant immunity and provides new genetic resources for the improvement of resistance to powdery mildew in wheat. © 2017 BSPP AND JOHN WILEY & SONS LTD.

  15. Engineering Hydrophobic Organosilica Nanoparticle-Doped Nanofibers for Enhanced and Fouling Resistant Membrane Distillation

    KAUST Repository

    Hammami, Mohamed Amen; Croissant, Jonas G.; Francis, Lijo; Alsaiari, Shahad K.; Anjum, Dalaver H.; Ghaffour, NorEddine; Khashab, Niveen M.

    2016-01-01

    Engineering and scaling-up new materials for better water desalination are imperative to find alternative fresh water sources to meet future demands. Herein, the fabrication of hydrophobic poly(ether imide) composite nanofiber membranes doped with novel ethylene-pentafluorophenylene-based periodic mesoporous organosilica nanoparticles is reported for enhanced and fouling resistant membrane distillation. Novel organosilica nanoparticles were homogeneously incorporated into electrospun nanofiber membranes depicting a proportional increase of hydrophobicity to the particle contents. Direct contact membrane distillation experiments on the organosilica-doped membrane with only 5% doping showed an increase of flux of 140% compared to commercial membranes. The high porosity of organosilica nanoparticles was further utilized to load the eugenol antimicrobial agent which produced a dramatic enhancement of the antibiofouling properties of the membrane of 70% after 24 h.

  16. Engineering Hydrophobic Organosilica Nanoparticle-Doped Nanofibers for Enhanced and Fouling Resistant Membrane Distillation

    KAUST Repository

    Hammami, Mohamed Amen

    2016-12-15

    Engineering and scaling-up new materials for better water desalination are imperative to find alternative fresh water sources to meet future demands. Herein, the fabrication of hydrophobic poly(ether imide) composite nanofiber membranes doped with novel ethylene-pentafluorophenylene-based periodic mesoporous organosilica nanoparticles is reported for enhanced and fouling resistant membrane distillation. Novel organosilica nanoparticles were homogeneously incorporated into electrospun nanofiber membranes depicting a proportional increase of hydrophobicity to the particle contents. Direct contact membrane distillation experiments on the organosilica-doped membrane with only 5% doping showed an increase of flux of 140% compared to commercial membranes. The high porosity of organosilica nanoparticles was further utilized to load the eugenol antimicrobial agent which produced a dramatic enhancement of the antibiofouling properties of the membrane of 70% after 24 h.

  17. Enhanced Arabidopsis disease resistance against Botrytis cinerea induced by sulfur dioxide.

    Science.gov (United States)

    Xue, Meizhao; Yi, Huilan

    2018-01-01

    Sulfur dioxide (SO 2 ) is a common air pollutant that has complex impacts on plants. The effect of prior exposure to 30mgm -3 SO 2 on defence against Botrytis cinerea (B. cinerea) in Arabidopsis thaliana and the possible mechanisms of action were investigated. The results indicated that pre-exposure to 30mgm -3 SO 2 resulted in significantly enhanced resistance to B. cinerea infection. SO 2 pre-treatment significantly enhanced the activities of defence-related enzymes including phenylalanine ammonia-lyase (PAL), polyphenol oxidase (PPO), β-1,3-glucanase (BGL) and chitinase (CHI). Transcripts of the defence-related genes PAL, PPO, PR2, and PR3, encoding PAL, PPO, BGL and CHI, respectively, were markedly elevated in Arabidopsis plants pre-exposed to SO 2 and subsequently inoculated with B. cinerea (SO 2 + treatment group) compared with those that were only treated with SO 2 (SO 2 ) or inoculated with B. cinerea (CK+). Moreover, SO 2 pre-exposure also led to significant increases in the expression levels of MIR393, MIR160 and MIR167 in Arabidopsis. Meanwhile, the expression of known targets involved in the auxin signalling pathway, was negatively correlated with their corresponding miRNAs. Additionally, the transcript levels of the primary auxin-response genes GH3-like, BDL/IAA12, and AXR3/IAA17 were markedly repressed. Our findings indicate that 30mgm -3 SO 2 pre-exposure enhances disease resistance against B. cinerea in Arabidopsis by priming defence responses through enhancement of defence-related gene expression and enzyme activity, and miRNA-mediated suppression of the auxin signalling pathway. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Sensitivity enhancement of polysilicon piezo-resistive pressure sensors with phosphorous diffused resistors

    International Nuclear Information System (INIS)

    Sivakumar, K; Dasgupta, N; Bhat, K N; Natarajan, K

    2006-01-01

    It is generally accepted that the piezo-resistive coefficient in single crystal silicon is higher when P-type impurities such as boron are used for doping the resistors. In this paper we demonstrate that the sensitivity of polycrystalline silicon piezo-resistive pressure sensors can be enhanced considerably when phosphorus diffusion source is used instead of boron dopant for realizing the piezo-resistors. Pressure sensors have been designed and fabricated with the polycrystalline piezo-resistors connected in the form of a Wheatstone bridge and laid out on thermal oxide grown on membranes obtained with a Silicon On Insulator (SOI) approach. The SOI wafers required for this purpose have been realized in-house by Silicon Fusion Bonding (SFB) and etch back technique in our laboratory. This approach provides excellent isolation between the resistors and enables zero temperature coefficient of the polysilicon resistor. The results obtained in our laboratory have clearly demonstrated that by optimizing the phosphorus diffusion temperature and duration, it is possible to achieve sensitivities in excess of 20mV /Bar for bridge input voltage of 10V, with linearity within 1% over a differential pressure range up to 10Bar (10 6 Pascal), and burst pressure in excess of 50 Bar as compared to the 10mV /Bar sensitivity obtained with boron doped polysilicon piezo-resistors. This enhancement is attributed to grain boundary passivation by phosphorous atoms

  19. Cold water immersion enhances recovery of submaximal muscle function after resistance exercise.

    Science.gov (United States)

    Roberts, Llion A; Nosaka, Kazunori; Coombes, Jeff S; Peake, Jonathan M

    2014-10-15

    We investigated the effect of cold water immersion (CWI) on the recovery of muscle function and physiological responses after high-intensity resistance exercise. Using a randomized, cross-over design, 10 physically active men performed high-intensity resistance exercise followed by one of two recovery interventions: 1) 10 min of CWI at 10°C or 2) 10 min of active recovery (low-intensity cycling). After the recovery interventions, maximal muscle function was assessed after 2 and 4 h by measuring jump height and isometric squat strength. Submaximal muscle function was assessed after 6 h by measuring the average load lifted during 6 sets of 10 squats at 80% of 1 repetition maximum. Intramuscular temperature (1 cm) was also recorded, and venous blood samples were analyzed for markers of metabolism, vasoconstriction, and muscle damage. CWI did not enhance recovery of maximal muscle function. However, during the final three sets of the submaximal muscle function test, participants lifted a greater load (P work during subsequent training sessions, which could enhance long-term training adaptations. Copyright © 2014 the American Physiological Society.

  20. Enhanced antimicrobial properties, cytocompatibility, and corrosion resistance of plasma-modified biodegradable magnesium alloys.

    Science.gov (United States)

    Zhao, Ying; Jamesh, Mohammed Ibrahim; Li, Wing Kan; Wu, Guosong; Wang, Chenxi; Zheng, Yufeng; Yeung, Kelvin W K; Chu, Paul K

    2014-01-01

    Magnesium alloys are potential biodegradable materials and have received increasing attention due to their outstanding biological performance and mechanical properties. However, rapid degradation in the physiological environment and potential toxicity limit clinical applications. Recently, special magnesium-calcium (Mg-Ca) and magnesium-strontium (Mg-Sr) alloys with biocompatible chemical compositions have been reported, but the rapid degradation still does not meet clinical requirements. In order to improve the corrosion resistance, a rough, hydrophobic and ZrO(2)-containing surface film is fabricated on Mg-Ca and Mg-Sr alloys by dual zirconium and oxygen ion implantation. Weight loss measurements and electrochemical corrosion tests show that the corrosion rate of the Mg-Ca and Mg-Sr alloys is reduced appreciably after surface treatment. A systematic investigation of the in vitro cellular response and antibacterial capability of the modified binary magnesium alloys is performed. The amounts of adherent bacteria on the Zr-O-implanted and Zr-implanted samples diminish remarkably compared to the unimplanted control. In addition, significantly enhanced cell adhesion and proliferation are observed from the Zr-O-implanted sample. The results suggest that dual zirconium and oxygen ion implantation, which effectively enhances the corrosion resistance, in vitro biocompatibility and antimicrobial properties of Mg-Ca and Mg-Sr alloys, provides a simple and practical means to expedite clinical acceptance of biodegradable magnesium alloys. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  1. Enhanced disease resistance and drought tolerance in transgenic rice plants overexpressing protein elicitors from Magnaporthe oryzae.

    Science.gov (United States)

    Wang, Zhenzhen; Han, Qiang; Zi, Qian; Lv, Shun; Qiu, Dewen; Zeng, Hongmei

    2017-01-01

    Exogenous application of the protein elicitors MoHrip1 and MoHrip2, which were isolated from the pathogenic fungus Magnaporthe oryzae (M. oryzae), was previously shown to induce a hypersensitive response in tobacco and to enhance resistance to rice blast. In this work, we successfully transformed rice with the mohrip1 and mohrip2 genes separately. The MoHrip1 and MoHrip2 transgenic rice plants displayed higher resistance to rice blast and stronger tolerance to drought stress than wild-type (WT) rice and the vector-control pCXUN rice. The expression of salicylic acid (SA)- and abscisic acid (ABA)-related genes was also increased, suggesting that these two elicitors may trigger SA signaling to protect the rice from damage during pathogen infection and regulate the ABA content to increase drought tolerance in transgenic rice. Trypan blue staining indicated that expressing MoHrip1 and MoHrip2 in rice plants inhibited hyphal growth of the rice blast fungus. Relative water content (RWC), water usage efficiency (WUE) and water loss rate (WLR) were measured to confirm the high capacity for water retention in transgenic rice. The MoHrip1 and MoHrip2 transgenic rice also exhibited enhanced agronomic traits such as increased plant height and tiller number.

  2. Regulation of the glucocorticoid receptor via a BET-dependent enhancer drives antiandrogen resistance in prostate cancer.

    Science.gov (United States)

    Shah, Neel; Wang, Ping; Wongvipat, John; Karthaus, Wouter R; Abida, Wassim; Armenia, Joshua; Rockowitz, Shira; Drier, Yotam; Bernstein, Bradley E; Long, Henry W; Freedman, Matthew L; Arora, Vivek K; Zheng, Deyou; Sawyers, Charles L

    2017-09-11

    In prostate cancer, resistance to the antiandrogen enzalutamide (Enz) can occur through bypass of androgen receptor (AR) blockade by the glucocorticoid receptor (GR). In contrast to fixed genomic alterations, here we show that GR-mediated antiandrogen resistance is adaptive and reversible due to regulation of GR expression by a tissue-specific enhancer. GR expression is silenced in prostate cancer by a combination of AR binding and EZH2-mediated repression at the GR locus, but is restored in advanced prostate cancers upon reversion of both repressive signals. Remarkably, BET bromodomain inhibition resensitizes drug-resistant tumors to Enz by selectively impairing the GR signaling axis via this enhancer. In addition to revealing an underlying molecular mechanism of GR-driven drug resistance, these data suggest that inhibitors of broadly active chromatin-readers could have utility in nuanced clinical contexts of acquired drug resistance with a more favorable therapeutic index.

  3. Laser cladding of copper with molybdenum for wear resistance enhancement in electrical contacts

    International Nuclear Information System (INIS)

    Ng, K.W.; Man, H.C.; Cheng, F.T.; Yue, T.M.

    2007-01-01

    Laser cladding of Mo on Cu has been attempted with the aim of enhancing the wear resistance and hence increasing the service life of electrical contacts made of Cu. In order to overcome the difficulties arising from the large difference in thermal properties and the low mutual solubility between Cu and Mo, Ni was introduced as an intermediate layer between Mo and Cu. The Ni and Mo layers were laser clad one after the other to form a sandwich layer of Mo/Ni/Cu. Excellent bonding between the clad layer and the Cu substrate was ensured by strong metallurgical bonding. The hardness of the surface of the clad layer is seven times higher than that of the Cu substrate. Pin-on-disc wear tests consistently showed that the abrasive wear resistance of the clad layer was also improved by a factor of seven as compared with untreated Cu substrate. The specific electrical contact resistance of the clad surface was about 5.6 x 10 -7 Ω cm 2

  4. Enhanced corrosion resistance of magnesium alloy AM60 by cerium(III) in chloride solution

    Energy Technology Data Exchange (ETDEWEB)

    Heakal, F. El-Taib, E-mail: fakihaheakal@yahoo.com [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt); Shehata, O.S. [Physical Chemistry Department, National Research Centre, Dokki, Giza (Egypt); Tantawy, N.S. [Girl' s College of Arts, Science and Education, Ain Shams University, Asma Fahmi Street, Cairo (Egypt)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Corrosion rate of AM60 in Cl{sup -} solution decreases with increasing [Ce{sup 3+}] up to 1 mM. Black-Right-Pointing-Pointer Beyond that level the corrosion rate increases and then stabilizes. Black-Right-Pointing-Pointer The spontaneously formed film characterises by increasing resistance with time. Black-Right-Pointing-Pointer The converted film after 10 d immersion exhibits self-healing in plain Cl{sup -} solution. Black-Right-Pointing-Pointer Ce(III) should be present in the corrodent to form a more compact surface coating. - Abstract: Cerium(III) was utilised to enhance the corrosion resistance of AM60 in NaCl solution. Ce{sup 3+} can suppress corrosion deterioration up to 1.0 mM. Beyond that level corrosion rate increases till a steady value. Surface film resistance increases with time evolution until 24 h, then decreases and stabilizes. The converted film after 240 h immersion exhibits self-healing and thickening when re-exposed to plain chloride solution. SEM and EDX confirmed that when Ce is present as additive in solution, more compact coating is formed better than its presence as a post coating on the alloy surface before being immersed in the corrosive environment.

  5. Enhanced corrosion resistance of magnesium alloy AM60 by cerium(III) in chloride solution

    International Nuclear Information System (INIS)

    Heakal, F. El-Taib; Shehata, O.S.; Tantawy, N.S.

    2012-01-01

    Highlights: ► Corrosion rate of AM60 in Cl − solution decreases with increasing [Ce 3+ ] up to 1 mM. ► Beyond that level the corrosion rate increases and then stabilizes. ► The spontaneously formed film characterises by increasing resistance with time. ► The converted film after 10 d immersion exhibits self-healing in plain Cl − solution. ► Ce(III) should be present in the corrodent to form a more compact surface coating. - Abstract: Cerium(III) was utilised to enhance the corrosion resistance of AM60 in NaCl solution. Ce 3+ can suppress corrosion deterioration up to 1.0 mM. Beyond that level corrosion rate increases till a steady value. Surface film resistance increases with time evolution until 24 h, then decreases and stabilizes. The converted film after 240 h immersion exhibits self-healing and thickening when re-exposed to plain chloride solution. SEM and EDX confirmed that when Ce is present as additive in solution, more compact coating is formed better than its presence as a post coating on the alloy surface before being immersed in the corrosive environment.

  6. Enhanced wear resistance of production tools and steel samples by implantation of nitrogen and carbon ions

    International Nuclear Information System (INIS)

    Mikkelsen, N.J.; Straede, C.A.

    1992-01-01

    In recent years ion implantation has become a feasible technique for obtaining improved wear resistance of production tools. However, basic knowledge of how and in which cases ion implantation is working at its best is still needed. The present paper discusses structural and tribological investigations of carbon and nitrogen implanted steels. The nitrogen data were obtained mainly from field tests and the investigation of carbon implantations took place mainly in the laboratory. A study was made of how the tribological behaviour of implanted steels changes with different implantation parameters. The tribological laboratory investigations were carried out using pin-on-disc equipment under controlled test conditions, and deal with high dose carbon implantation (approximately (1-2)x10 18 ions cm -2 ). The wear resistance of steels was enhanced dramatically, by up to several orders of magnitude. The field test results cover a broad range of ion implanted production tools, which showed a marked improvement in wear resistance. Nitrogen implanted tools are also compared with carbon and titanium implanted tools. (orig.)

  7. A single bout of resistance exercise can enhance episodic memory performance.

    Science.gov (United States)

    Weinberg, Lisa; Hasni, Anita; Shinohara, Minoru; Duarte, Audrey

    2014-11-01

    Acute aerobic exercise can be beneficial to episodic memory. This benefit may occur because exercise produces a similar physiological response as physical stressors. When administered during consolidation, acute stress, both physical and psychological, consistently enhances episodic memory, particularly memory for emotional materials. Here we investigated whether a single bout of resistance exercise performed during consolidation can produce episodic memory benefits 48 h later. We used a one-leg knee extension/flexion task for the resistance exercise. To assess the physiological response to the exercise, we measured salivary alpha amylase (a biomarker of central norepinephrine), heart rate, and blood pressure. To test emotional episodic memory, we used a remember-know recognition memory paradigm with equal numbers of positive, negative, and neutral IAPS images as stimuli. The group that performed the exercise, the active group, had higher overall recognition accuracy than the group that did not exercise, the passive group. We found a robust effect of valence across groups, with better performance on emotional items as compared to neutral items and no difference between positive and negative items. This effect changed based on the physiological response to the exercise. Within the active group, participants with a high physiological response to the exercise were impaired for neutral items as compared to participants with a low physiological response to the exercise. Our results demonstrate that a single bout of resistance exercise performed during consolidation can enhance episodic memory and that the effect of valence on memory depends on the physiological response to the exercise. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Alternating current electrical stimulation enhanced chemotherapy: a novel strategy to bypass multidrug resistance in tumor cells

    International Nuclear Information System (INIS)

    Janigro, Damir; Perju, Catalin; Fazio, Vincent; Hallene, Kerri; Dini, Gabriele; Agarwal, Mukesh K; Cucullo, Luca

    2006-01-01

    Tumor burden can be pharmacologically controlled by inhibiting cell division and by direct, specific toxicity to the cancerous tissue. Unfortunately, tumors often develop intrinsic pharmacoresistance mediated by specialized drug extrusion mechanisms such as P-glycoprotein. As a consequence, malignant cells may become insensitive to various anti-cancer drugs. Recent studies have shown that low intensity very low frequency electrical stimulation by alternating current (AC) reduces the proliferation of different tumor cell lines by a mechanism affecting potassium channels while at intermediate frequencies interfere with cytoskeletal mechanisms of cell division. The aim of the present study is to test the hypothesis that permeability of several MDR1 over-expressing tumor cell lines to the chemotherapic agent doxorubicin is enhanced by low frequency, low intensity AC stimulation. We grew human and rodent cells (C6, HT-1080, H-1299, SKOV-3 and PC-3) which over-expressed MDR1 in 24-well Petri dishes equipped with an array of stainless steel electrodes connected to a computer via a programmable I/O board. We used a dedicated program to generate and monitor the electrical stimulation protocol. Parallel cultures were exposed for 3 hours to increasing concentrations (1, 2, 4, and 8 μM) of doxorubicin following stimulation to 50 Hz AC (7.5 μA) or MDR1 inhibitor XR9576. Cell viability was assessed by determination of adenylate kinase (AK) release. The relationship between MDR1 expression and the intracellular accumulation of doxorubicin as well as the cellular distribution of MDR1 was investigated by computerized image analysis immunohistochemistry and Western blot techniques. By the use of a variety of tumor cell lines, we show that low frequency, low intensity AC stimulation enhances chemotherapeutic efficacy. This effect was due to an altered expression of intrinsic cellular drug resistance mechanisms. Immunohistochemical, Western blot and fluorescence analysis revealed

  9. Bipolar resistive switching characteristics of low temperature grown ZnO thin films by plasma-enhanced atomic layer deposition

    International Nuclear Information System (INIS)

    Zhang Jian; Yang Hui; Zhang Qilong; Dong Shurong; Luo, J. K.

    2013-01-01

    ZnO films deposited by plasma-enhanced atomic layer deposition (PEALD) have been used to investigate resistive memory behavior. The bipolar resistance switching properties were observed in the Al/PEALD-ZnO/Pt devices. The resistance ratio for the high and low resistance states (HRS/LRS) is more than 10 3 , better than ZnO devices deposited by other methods. The dominant conduction mechanisms of HRS and LRS are trap-controlled space charge limited current and Ohmic behavior, respectively. The resistive switching behavior is induced upon the formation/disruption of conducting filaments. This study demonstrated that the PEALD-ZnO films have better properties for the application in 3D resistance random access memory.

  10. Stress-enhanced fear learning in rats is resistant to the effects of immediate massed extinction

    Science.gov (United States)

    Long, Virginia A.; Fanselow, Michael S.

    2014-01-01

    Enhanced fear learning occurs subsequent to traumatic or stressful events and is a persistent challenge to the treatment of post-traumatic stress disorder (PTSD). Facilitation of learning produced by prior stress can elicit an exaggerated fear response to a minimally aversive event or stimulus. Stress-enhanced fear learning (SEFL) is a rat model of PTSD; rats previously exposed to the SEFL 15 electrical shocks procedure exhibit several behavioral responses similar to those seen in patients with PTSD. However, past reports found that SEFL is not mitigated by extinction (a model of exposure therapy) when the spaced extinction began 24 h after stress. Recent studies found that extinction from 10 min to 1 h subsequent to fear conditioning “erased” learning, whereas later extinction, occurring from 24 to 72 h after conditioning did not. Other studies indicate that massed extinction is more effective than spaced procedures. Therefore, we examined the time-dependent nature of extinction on the stress-induced enhancement of fear learning using a massed trial’s procedure. Experimental rats received 15 foot shocks and were given either no extinction or massed extinction 10 min or 72 h later. Our present data indicate that SEFL, following traumatic stress, is resistant to immediate massed extinction. Experimental rats showed exaggerated new fear learning regardless of when extinction training occurred. Thus, post-traumatic reactivity such as SEFL does not seem responsive to extinction treatments. PMID:22176467

  11. Dragon enhances BMP signaling and increases transepithelial resistance in kidney epithelial cells.

    Science.gov (United States)

    Xia, Yin; Babitt, Jodie L; Bouley, Richard; Zhang, Ying; Da Silva, Nicolas; Chen, Shanzhuo; Zhuang, Zhenjie; Samad, Tarek A; Brenner, Gary J; Anderson, Jennifer L; Hong, Charles C; Schneyer, Alan L; Brown, Dennis; Lin, Herbert Y

    2010-04-01

    The neuronal adhesion protein Dragon acts as a bone morphogenetic protein (BMP) coreceptor that enhances BMP signaling. Given the importance of BMP signaling in nephrogenesis and its putative role in the response to injury in the adult kidney, we studied the localization and function of Dragon in the kidney. We observed that Dragon localized predominantly to the apical surfaces of tubular epithelial cells in the thick ascending limbs, distal convoluted tubules, and collecting ducts of mice. Dragon expression was weak in the proximal tubules and glomeruli. In mouse inner medullary collecting duct (mIMCD3) cells, Dragon generated BMP signals in a ligand-dependent manner, and BMP4 is the predominant endogenous ligand for the Dragon coreceptor. In mIMCD3 cells, BMP4 normally signaled through BMPRII, but Dragon enhanced its signaling through the BMP type II receptor ActRIIA. Dragon and BMP4 increased transepithelial resistance (TER) through the Smad1/5/8 pathway. In epithelial cells isolated from the proximal tubule and intercalated cells of collecting ducts, we observed coexpression of ActRIIA, Dragon, and BMP4 but not BMPRII. Taken together, these results suggest that Dragon may enhance BMP signaling in renal tubular epithelial cells and maintain normal renal physiology.

  12. Dietary Curcuma longa enhances resistance against Eimeria maxima and Eimeria tenella infections in chickens.

    Science.gov (United States)

    Kim, Duk Kyung; Lillehoj, Hyun S; Lee, Sung Hyen; Jang, Seung I; Lillehoj, Erik P; Bravo, David

    2013-10-01

    The effects of dietary supplementation with an organic extract of Curcuma longa on systemic and local immune responses to experimental Eimeria maxima and Eimeria tenella infections were evaluated in commercial broiler chickens. Dietary supplementation with C. longa enhanced coccidiosis resistance as demonstrated by increased BW gains, reduced fecal oocyst shedding, and decreased gut lesions compared with infected birds fed a nonsupplemented control diet. The chickens fed C. longa-supplemented diet showed enhanced systemic humoral immunity, as assessed by greater levels of serum antibodies to an Eimeria microneme protein, MIC2, and enhanced cellular immunity, as measured by concanavalin A-induced spleen cell proliferation, compared with controls. At the intestinal level, genome-wide gene expression profiling by microarray hybridization identified 601 differentially expressed transcripts (287 upregulated, 314 downregulated) in gut lymphocytes of C. longa-fed chickens compared with nonsupplemented controls. Based on the known functions of the corresponding mammalian genes, the C. longa-induced intestinal transcriptome was mostly associated with genes mediating anti-inflammatory effects. Taken together, these results suggest that dietary C. longa could be used to attenuate Eimeria-induced, inflammation-mediated gut damage in commercial poultry production.

  13. Radiation enhanced copper clustering processes in Fe-Cu alloys during electron and ion irradiations as measured by electrical resistivity

    International Nuclear Information System (INIS)

    Ishino, S.; Chimi, Y.; Bagiyono; Tobita, T.; Ishikawa, N.; Suzuki, M.; Iwase, A.

    2003-01-01

    To study the mechanism of radiation-enhanced clustering of copper atoms in Fe-Cu alloys, in situ electrical resistivity measurements are performed during irradiation with 100 MeV carbon ions and with 2 MeV electrons at 300 K. Two kinds of highly pure Fe-Cu alloys with Cu content of 0.02 and 0.6 wt% are used. The results are summarized as follows: - Although there is a steep initial resistivity increase below about 10 μdpa, the resistivity steadily decreases after this initial transient in Fe-0.6wt%Cu alloy, while in Fe-0.02wt%Cu alloy, the resistivity either decreases slowly or stays almost constant. The rate of change in resistivity depends on copper concentration. - The rate of change in resistivity per dpa is larger for electron irradiation than for ion irradiation. - Change in dose rate from 10 -8 to 10 -9 dpa/s slightly enhances the rate of resistivity change per dpa. The decrease in resistivity with dose is considered to be due to clustering or precipitation of copper atoms. The initial abrupt increase in resistivity is too large to be accounted for by initial introduction of point defects before copper clustering. Tentatively the phenomenon is explained as due to the formation of embryos of copper precipitates with a large strain field around them. Quantitative evaluation of the results using resistivity contribution of a unit concentration of Frenkel pairs and that of copper atoms gives an important conclusion that more than one copper atom are removed from solid solution by one Frenkel pair. The clustering efficiency is surprisingly high in the present case compared with the ordinary radiation-induced or radiation-enhanced precipitation processes

  14. Insecticide mixtures could enhance the toxicity of insecticides in a resistant dairy population of Musca domestica L [corrected].

    Directory of Open Access Journals (Sweden)

    Hafiz Azhar Ali Khan

    Full Text Available House flies, Musca domestica L., are important pests of dairy operations worldwide, with the ability to adapt wide range of environmental conditions. There are a number of insecticides used for their management, but development of resistance is a serious problem. Insecticide mixtures could enhance the toxicity of insecticides in resistant insect pests, thus resulting as a potential resistance management tool. The toxicity of bifenthrin, cypermethrin, deltamethrin, chlorpyrifos, profenofos, emamectin benzoate and fipronil were assessed separately, and in mixtures against house flies. A field-collected population was significantly resistant to all the insecticides under investigation when compared with a laboratory susceptible strain. Most of the insecticide mixtures like one pyrethroid with other compounds evaluated under two conditions (1∶1-"A" and LC50: LC50-"B" significantly increased the toxicity of pyrethroids in the field population. Under both conditions, the combination indices of pyrethroids with other compounds, in most of the cases, were significantly below 1, suggesting synergism. The enzyme inhibitors, PBO and DEF, when used in combination with insecticides against the resistant population, toxicities of bifenthrin, cypermethrin, deltamethrin and emamectin were significantly increased, suggesting esterase and monooxygenase based resistance mechanism. The toxicities of bifenthrin, cypermethrin and deltamethrin in the resistant population of house flies could be enhanced by the combination with chlorpyrifos, profenofos, emamectin and fipronil. The findings of the present study might have practical significance for resistance management in house flies.

  15. Insecticide Mixtures Could Enhance the Toxicity of Insecticides in a Resistant Dairy Population of Musca domestica L

    Science.gov (United States)

    Khan, Hafiz Azhar Ali; Akram, Waseem; Shad, Sarfraz Ali; Lee, Jong-Jin

    2013-01-01

    House flies, Musca domestica L., are important pests of dairy operations worldwide, with the ability to adapt wide range of environmental conditions. There are a number of insecticides used for their management, but development of resistance is a serious problem. Insecticide mixtures could enhance the toxicity of insecticides in resistant insect pests, thus resulting as a potential resistance management tool. The toxicity of bifenthrin, cypermethrin, deltamethrin, chlorpyrifos, profenofos, emamectin benzoate and fipronil were assessed separately, and in mixtures against house flies. A field-collected population was significantly resistant to all the insecticides under investigation when compared with a laboratory susceptible strain. Most of the insecticide mixtures like one pyrethroid with other compounds evaluated under two conditions (1∶1-“A” and LC50: LC50-“B”) significantly increased the toxicity of pyrethroids in the field population. Under both conditions, the combination indices of pyrethroids with other compounds, in most of the cases, were significantly below 1, suggesting synergism. The enzyme inhibitors, PBO and DEF, when used in combination with insecticides against the resistant population, toxicities of bifenthrin, cypermethrin, deltamethrin and emamectin were significantly increased, suggesting esterase and monooxygenase based resistance mechanism. The toxicities of bifenthrin, cypermethrin and deltamethrin in the resistant population of house flies could be enhanced by the combination with chlorpyrifos, profenofos, emamectin and fipronil. The findings of the present study might have practical significance for resistance management in house flies. PMID:23613758

  16. Motuporamine Derivatives as Antimicrobial Agents and Antibiotic Enhancers against Resistant Gram-Negative Bacteria.

    Science.gov (United States)

    Borselli, Diane; Blanchet, Marine; Bolla, Jean-Michel; Muth, Aaron; Skruber, Kristen; Phanstiel, Otto; Brunel, Jean Michel

    2017-02-01

    Dihydromotuporamine C and its derivatives were evaluated for their in vitro antimicrobial activities and antibiotic enhancement properties against Gram-negative bacteria and clinical isolates. The mechanism of action of one of these derivatives, MOTU-N44, was investigated against Enterobacter aerogenes by using fluorescent dyes to evaluate outer-membrane depolarization and permeabilization. Its efficiency correlated with inhibition of dye transport, thus suggesting that these molecules inhibit drug transporters by de-energization of the efflux pump rather than by direct interaction of the molecule with the pump. This suggests that depowering the efflux pump provides another strategy to address antibiotic resistance. © 2017 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  17. Reward acts on the pFC to enhance distractor resistance of working memory representations.

    Science.gov (United States)

    Fallon, Sean James; Cools, Roshan

    2014-12-01

    Working memory and reward processing are often thought to be separate, unrelated processes. However, most daily activities involve integrating these two types of information, and the two processes rarely, if ever, occur in isolation. Here, we show that working memory and reward interact in a task-dependent manner and that this task-dependent interaction involves modulation of the pFC by the ventral striatum. Specifically, BOLD signal during gains relative to losses in the ventral striatum and pFC was associated not only with enhanced distractor resistance but also with impairment in the ability to update working memory representations. Furthermore, the effect of reward on working memory was accompanied by differential coupling between the ventral striatum and ignore-related regions in the pFC. Together, these data demonstrate that reward-related signals modulate the balance between cognitive stability and cognitive flexibility by altering functional coupling between the ventral striatum and the pFC.

  18. Enhancing the formation and shear resistance of nitrifying biofilms on membranes by surface modification

    DEFF Research Database (Denmark)

    Lackner, Susanne; Holmberg, Maria; Terada, Akihiko

    2009-01-01

    Polypropylene (PP) membranes and polyethylene (PE) surfaces were modified to enhance formation and shear resistance of nitrifying biofilms for wastewater treatment applications. A combination of plasma polymerization and wet chemistry was employed to ultimately introduce poly(ethyleneglycol) (PEG......) chains with two different functional groups (-PEG-NH2 and -PEG-CH3). Biofilm growth experiments using a mixed nitrifying bacterial culture revealed that the specific combination of PEG chains with amino groups resulted in most biofilm formation on both PP and PE samples. Detachment experiments showed...... structure might be possible explanations of the superiority of the -PEG-NH2 modification. The success of the-PEG-NH2 modification was independent of the original surface and might, therefore, be used in wastewater treatment bioreactors to improve reactor performance by making biofilm formation more stable...

  19. Enhancement of bile resistance in Lactobacillus plantarum strains by soy lecithin.

    Science.gov (United States)

    Hu, B; Tian, F; Wang, G; Zhang, Q; Zhao, J; Zhang, H; Chen, W

    2015-07-01

    This study evaluated the effect of soy lecithin on the bile resistance of Lactobacillus plantarum. Six strains were cultured in MRS broth supplemented with soy lecithin at different concentrations. The strains incubated in MRS broth with 1·0% soy lecithin showed no inhibitory effect on cell growth. After culturing in MRS broth with 0·2-1·0% soy lecithin, the survival rate of harvested cells increased significantly (P bile challenge compared with the no added soy lecithin group. The cells incubated with 0·6% soy lecithin were able to grow in an MRS broth with a higher bile salt content. The surface hydrophobicity and cell leakage in the bile challenge were assessed to reveal the physical changes caused by the addition of soy lecithin. The cell surface hydrophobicity was enhanced and the membrane integrity in the bile challenge increased after culturing with soy lecithin. A shift in the fatty acid composition was also observed, illustrating the cell membrane change in the soy lecithin culture. In this study, we report for the first time the beneficial effect of adding soy lecithin to an MRS broth on subsequent bile tolerance of Lactobacillus plantarum. Soy lecithin had no inhibitory effect on strain viability but significantly enhanced bile resistance. Surface hydrophobicity and cell integrity increased in strains cultured with soy lecithin. The observed shift in the cell fatty acid composition indicated changes to the cell membrane. As soy lecithin is safe for use in the food industry, its protective effects can be harnessed for the development of bile-sensitive strains with health-benefit functions for use in probiotic products. © 2015 The Society for Applied Microbiology.

  20. Enhanced resistance to soybean cyst nematode Heterodera glycines in transgenic soybean by silencing putative CLE receptors.

    Science.gov (United States)

    Guo, Xiaoli; Chronis, Demosthenis; De La Torre, Carola M; Smeda, John; Wang, Xiaohong; Mitchum, Melissa G

    2015-08-01

    CLE peptides are small extracellular proteins important in regulating plant meristematic activity through the CLE-receptor kinase-WOX signalling module. Stem cell pools in the SAM (shoot apical meristem), RAM (root apical meristem) and vascular cambium are controlled by CLE signalling pathways. Interestingly, plant-parasitic cyst nematodes secrete CLE-like effector proteins, which act as ligand mimics of plant CLE peptides and are required for successful parasitism. Recently, we demonstrated that Arabidopsis CLE receptors CLAVATA1 (CLV1), the CLAVATA2 (CLV2)/CORYNE (CRN) heterodimer receptor complex and RECEPTOR-LIKE PROTEIN KINASE 2 (RPK2), which transmit the CLV3 signal in the SAM, are required for perception of beet cyst nematode Heterodera schachtii CLEs. Reduction in nematode infection was observed in clv1, clv2, crn, rpk2 and combined double and triple mutants. In an effort to develop nematode resistance in an agriculturally important crop, orthologues of Arabidopsis receptors including CLV1, CLV2, CRN and RPK2 were identified from soybean, a host for the soybean cyst nematode Heterodera glycines. For each of the receptors, there are at least two paralogues in the soybean genome. Localization studies showed that most receptors are expressed in the root, but vary in their level of expression and spatial expression patterns. Expression in nematode-induced feeding cells was also confirmed. In vitro direct binding of the soybean receptors with the HgCLE peptide was analysed. Knock-down of the receptors in soybean hairy roots showed enhanced resistance to SCN. Our findings suggest that targeted disruption of nematode CLE signalling may be a potential means to engineer nematode resistance in crop plants. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  1. Triclosan-immobilized polyamide thin film composite membranes with enhanced biofouling resistance

    Science.gov (United States)

    Park, Sang-Hee; Hwang, Seon Oh; Kim, Taek-Seung; Cho, Arah; Kwon, Soon Jin; Kim, Kyoung Taek; Park, Hee-Deung; Lee, Jung-Hyun

    2018-06-01

    We report on a strategy to improve biofouling resistance of a polyamide (PA) thin-film composite (TFC) reverse osmosis (RO) membrane via chemically immobilizing triclosan (TC), known as a common organic biocide, on its surface. To facilitate covalent attachment of TC on the membrane surface, TC was functionalized with amine moiety to prepare aminopropyl TC. Then, the TC-immobilized TFC (TFC-TC) membranes were fabricated through a one-step amide formation reaction between amine groups of aminopropyl TC and acyl chloride groups present on the PA membrane surface, which was confirmed by high-resolution XPS. Strong stability of the immobilized TC was also confirmed by a hydraulic washing test. Although the TFC-TC membrane showed slightly reduced separation performance compared to the pristine control, it still maintained a satisfactory RO performance level. Importantly, the TFC-TC membrane exhibited excellent antibacterial activity against both gram negative (E. coli and P. aeruginosa) and gram positive (S. aureus) bacteria along with greatly enhanced resistance to biofilm formation. Our immobilization approach offers a robust and relatively benign strategy to control biofouling of functional surfaces, films and membranes.

  2. A Novel Peptide from Soybean Protein Isolate Significantly Enhances Resistance of the Organism under Oxidative Stress.

    Directory of Open Access Journals (Sweden)

    Heran Ma

    Full Text Available Recent studies have indicated that protein hydrolysates have broad biological effects. In the current study we describe a novel antioxidative peptide, FDPAL, from soybean protein isolate (SPI. The aim of this study was to purify and characterize an antioxidative peptide from SPI and determine its antioxidative mechanism. LC-MS/MS was used to isolate and identify the peptide from SPI. The sequence of the peptide was determined to be Phe-Asp-Pro-Ala-Leu (FDPAL, 561 Da. FDPAL can cause significant enhancement of resistance to oxidative stress both in cells as well as simple organisms. In Caenorhabditis elegans (C. elegans, FDPAL can up-regulate the expression of certain genes associated with resistance. The antioxidant activity of this peptide can be attributed to the presence of a specific amino acid sequence. Results from our work suggest that FDPAL can facilitate potential applications of proteins carrying this sequence in the nutraceutical, bioactive material and clinical medicine areas, as well as in cosmetics and health care products.

  3. Arabidopsis EF-Tu receptor enhances bacterial disease resistance in transgenic wheat.

    Science.gov (United States)

    Schoonbeek, Henk-Jan; Wang, Hsi-Hua; Stefanato, Francesca L; Craze, Melanie; Bowden, Sarah; Wallington, Emma; Zipfel, Cyril; Ridout, Christopher J

    2015-04-01

    Perception of pathogen (or microbe)-associated molecular patterns (PAMPs/MAMPs) by pattern recognition receptors (PRRs) is a key component of plant innate immunity. The Arabidopsis PRR EF-Tu receptor (EFR) recognizes the bacterial PAMP elongation factor Tu (EF-Tu) and its derived peptide elf18. Previous work revealed that transgenic expression of AtEFR in Solanaceae confers elf18 responsiveness and broad-spectrum bacterial disease resistance. In this study, we developed a set of bioassays to study the activation of PAMP-triggered immunity (PTI) in wheat. We generated transgenic wheat (Triticum aestivum) plants expressing AtEFR driven by the constitutive rice actin promoter and tested their response to elf18. We show that transgenic expression of AtEFR in wheat confers recognition of elf18, as measured by the induction of immune marker genes and callose deposition. When challenged with the cereal bacterial pathogen Pseudomonas syringae pv. oryzae, transgenic EFR wheat lines had reduced lesion size and bacterial multiplication. These results demonstrate that AtEFR can be transferred successfully from dicot to monocot species, further revealing that immune signalling pathways are conserved across these distant phyla. As novel PRRs are identified, their transfer between plant families represents a useful strategy for enhancing resistance to pathogens in crops. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  4. Quercetin-Based Modified Porous Silicon Nanoparticles for Enhanced Inhibition of Doxorubicin-Resistant Cancer Cells.

    Science.gov (United States)

    Liu, Zehua; Balasubramanian, Vimalkumar; Bhat, Chinmay; Vahermo, Mikko; Mäkilä, Ermei; Kemell, Marianna; Fontana, Flavia; Janoniene, Agne; Petrikaite, Vilma; Salonen, Jarno; Yli-Kauhaluoma, Jari; Hirvonen, Jouni; Zhang, Hongbo; Santos, Hélder A

    2017-02-01

    One of the most challenging obstacles in nanoparticle's surface modification is to achieve the concept that one ligand can accomplish multiple purposes. Upon such consideration, 3-aminopropoxy-linked quercetin (AmQu), a derivative of a natural flavonoid inspired by the structure of dopamine, is designed and subsequently used to modify the surface of thermally hydrocarbonized porous silicon (PSi) nanoparticles. This nanosystem inherits several advanced properties in a single carrier, including promoted anticancer efficiency, multiple drug resistance (MDR) reversing, stimuli-responsive drug release, drug release monitoring, and enhanced particle-cell interactions. The anticancer drug doxorubicin (DOX) is efficiently loaded into this nanosystem and released in a pH-dependent manner. AmQu also effectively quenches the fluorescence of the loaded DOX, thereby allowing the use of the nanosystem for monitoring the intracellular drug release. Furthermore, a synergistic effect with the presence of AmQu is observed in both normal MCF-7 and DOX-resistant MCF-7 breast cancer cells. Due to the similar structure as dopamine, AmQu may facilitate both the interaction and internalization of PSi into the cells. Overall, this PSi-based platform exhibits remarkable superiority in both multifunctionality and anticancer efficiency, making this nanovector a promising system for anti-MDR cancer treatment. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. A CRISPR-Cas system enhances envelope integrity mediating antibiotic resistance and inflammasome evasion.

    Science.gov (United States)

    Sampson, Timothy R; Napier, Brooke A; Schroeder, Max R; Louwen, Rogier; Zhao, Jinshi; Chin, Chui-Yoke; Ratner, Hannah K; Llewellyn, Anna C; Jones, Crystal L; Laroui, Hamed; Merlin, Didier; Zhou, Pei; Endtz, Hubert P; Weiss, David S

    2014-07-29

    Clustered, regularly interspaced, short palindromic repeats-CRISPR associated (CRISPR-Cas) systems defend bacteria against foreign nucleic acids, such as during bacteriophage infection and transformation, processes which cause envelope stress. It is unclear if these machineries enhance membrane integrity to combat this stress. Here, we show that the Cas9-dependent CRISPR-Cas system of the intracellular bacterial pathogen Francisella novicida is involved in enhancing envelope integrity through the regulation of a bacterial lipoprotein. This action ultimately provides increased resistance to numerous membrane stressors, including antibiotics. We further find that this previously unappreciated function of Cas9 is critical during infection, as it promotes evasion of the host innate immune absent in melanoma 2/apoptosis associated speck-like protein containing a CARD (AIM2/ASC) inflammasome. Interestingly, the attenuation of the cas9 mutant is complemented only in mice lacking both the AIM2/ASC inflammasome and the bacterial lipoprotein sensor Toll-like receptor 2, but not in single knockout mice, demonstrating that Cas9 is essential for evasion of both pathways. These data represent a paradigm shift in our understanding of the function of CRISPR-Cas systems as regulators of bacterial physiology and provide a framework with which to investigate the roles of these systems in myriad bacteria, including pathogens and commensals.

  6. Ectopic Expression of JcWRKY Confers Enhanced Resistance in Transgenic Tobacco Against Macrophomina phaseolina.

    Science.gov (United States)

    Agarwal, Parinita; Patel, Khantika; Agarwal, Pradeep K

    2018-04-01

    Plants possess an innate immune system comprising of a complex network of closely regulated defense responses involving differential gene expression mediated by transcription factors (TFs). The WRKYs comprise of an important plant-specific TF family, which is involved in regulation of biotic and abiotic defenses. The overexpression of JcWRKY resulted in improved resistance in transgenic tobacco against Macrophomina phaseolina. The production of reactive oxygen species (ROS) and its detoxification through antioxidative system in the transgenics facilitates defense against Macrophomina. The enhanced catalase activity on Macrophomina infection limits the spread of infection. The transcript expression of antioxidative enzymes gene (CAT and SOD) and salicylic acid (SA) biosynthetic gene ICS1 showed upregulation during Macrophomina infection and combinatorial stress. The enhanced transcript of pathogenesis-related genes PR-1 indicates the accumulation of SA during different stresses. The PR-2 and PR-5 highlight the activation of defense responses comprising of activation of hydrolytic cleavage of glucanases and thaumatin-like proteins causing disruption of fungal cells. The ROS homeostasis in coordination with signaling molecules regulate the defense responses and inhibit fungal growth.

  7. Enhanced Cadmium (Cd Phytoextraction from Contaminated Soil using Cd-Resistant Bacterium

    Directory of Open Access Journals (Sweden)

    Kunchaya Setkit

    2014-01-01

    Full Text Available A cadmium (Cd-resistant bacterium, Micrococcus sp. MU1, is able to produce indole-3-acetic acid and promotes root elongation and plant growth. The potential of this bacterium on enhancement of Cd uptake and bioaccumulation of Cd in Helianthus annuus L. planted in Cd-contaminated soil was evaluated in greenhouse condition. The results showed that Micrococcus sp. MU1promoted the growth of H. annuus L. by increasing the root length, stem height, dry biomass, root to shoot ratio and also significantly increased Cd accumulation in the root and above-ground tissues of H. annuus L. compared to uninoculated control. Re-inoculation with Micrococcus sp. MU1in contaminated soil helped in promoting plant growth and Cd phytoextraction throughout the cultivation period. In addition, phytoextraction coefficient and translocation factor (TF of H. annuus L. inoculated with Micrococcus sp. MU1were higher than that of uninoculated control and TF continuously increased with time. Our results suggested that Micrococcus sp. MU1 has an ability to enhance plant growth and Cd uptake in H. annuus L. Synergistic interaction between Micrococcus sp. MU1 and H. annuus L. could be further applied for Cd phytoextraction in polluted areas.

  8. Fruit-Enhanced Resistance to Microbial Infection Induced by Selective Laser Excitation

    Directory of Open Access Journals (Sweden)

    Alicia G. Gonzálvez

    2013-01-01

    Full Text Available Table grapes were irradiated with laser pulses at two different wavelengths: one selected at 302.1 nm, that is, resonant with the transresveratrol biphoton absorption band, and another selected at 300 nm, that is a nonresonant wavelength where trans-resveratrol two-photon absorption is negligible. Attenuated total reflectance Fourier transformed infrared spectroscopic analyses of the irradiated grapes' skin showed an enhancement of polyphenols' content when the resonant wavelength was employed. Furthermore, microbiological analysis performed with nontreated (control, nonresonant, and resonantly irradiated grapes demonstrated how the last samples developed a significantly lower number of colony forming units. Since the only difference between the two (resonant and nonresonant irradiation conditions was just a couple of nanometres in the employed UV-B laser wavelengths, the germicidal effect should be considered very similar. As a result, the observed difference in the table grape resistance to microbial infection was attributed to a wavelength-dependent-induced photochemistry. Finally, the potentiality of this method to enhance the postharvest health status of table grapes is remarked.

  9. Expression of rabbit IL-4 by recombinant myxoma viruses enhances virulence and overcomes genetic resistance to myxomatosis.

    Science.gov (United States)

    Kerr, P J; Perkins, H D; Inglis, B; Stagg, R; McLaughlin, E; Collins, S V; Van Leeuwen, B H

    2004-06-20

    Rabbit IL-4 was expressed in the virulent standard laboratory strain (SLS) and the attenuated Uriarra (Ur) strain of myxoma virus with the aim of creating a Th2 cytokine environment and inhibiting the development of an antiviral cell-mediated response to myxomatosis in infected rabbits. This allowed testing of a model for genetic resistance to myxomatosis in wild rabbits that have undergone 50 years of natural selection for resistance to myxomatosis. Expression of IL-4 significantly enhanced virulence of both virulent and attenuated virus strains in susceptible (laboratory) and resistant (wild) rabbits. SLS-IL-4 completely overcame genetic resistance in wild rabbits. The pathogenesis of SLS-IL-4 was compared in susceptible and resistant rabbits. The results support a model for resistance to myxomatosis of an enhanced innate immune response controlling virus replication and allowing an effective antiviral cell-mediated immune response to develop in resistant rabbits. Expression of IL-4 did not overcome immunity to myxomatosis induced by immunization.

  10. Overexpression of Phosphomimic Mutated OsWRKY53 Leads to Enhanced Blast Resistance in Rice

    Science.gov (United States)

    Ogawa, Satoshi; Masuda, Yuka; Shimizu, Takafumi; Kishi-Kaboshi, Mitsuko; Takahashi, Akira; Nishizawa, Yoko; Minami, Eiichi; Nojiri, Hideaki; Yamane, Hisakazu; Okada, Kazunori

    2014-01-01

    WRKY transcription factors and mitogen-activated protein kinase (MAPK) cascades have been shown to play pivotal roles in the regulation of plant defense responses. We previously reported that OsWRKY53-overexpressing rice plants showed enhanced resistance to the rice blast fungus. In this study, we identified OsWRKY53 as a substrate of OsMPK3/OsMPK6, components of a fungal PAMP-responsive MAPK cascade in rice, and analyzed the effect of OsWRKY53 phosphorylation on the regulation of basal defense responses to a virulence race of rice blast fungus Magnaporthe oryzae strain Ina86-137. An in vitro phosphorylation assay revealed that the OsMPK3/OsMPK6 activated by OsMKK4 phosphorylated OsWRKY53 recombinant protein at its multiple clustered serine-proline residues (SP cluster). When OsWRKY53 was coexpressed with a constitutively active mutant of OsMKK4 in a transient reporter gene assay, the enhanced transactivation activity of OsWRKY53 was found to be dependent on phosphorylation of the SP cluster. Transgenic rice plants overexpressing a phospho-mimic mutant of OsWRKY53 (OsWRKY53SD) showed further-enhanced disease resistance to the blast fungus compared to native OsWRKY53-overexpressing rice plants, and a substantial number of defense-related genes, including pathogenesis-related protein genes, were more upregulated in the OsWRKY53SD-overexpressing plants compared to the OsWRKY53-overexpressing plants. These results strongly suggest that the OsMKK4-OsMPK3/OsMPK6 cascade regulates transactivation activity of OsWRKY53, and overexpression of the phospho-mimic mutant of OsWRKY53 results in a major change to the rice transcriptome at steady state that leads to activation of a defense response against the blast fungus in rice plants. PMID:24892523

  11. Overexpression of phosphomimic mutated OsWRKY53 leads to enhanced blast resistance in rice.

    Directory of Open Access Journals (Sweden)

    Tetsuya Chujo

    Full Text Available WRKY transcription factors and mitogen-activated protein kinase (MAPK cascades have been shown to play pivotal roles in the regulation of plant defense responses. We previously reported that OsWRKY53-overexpressing rice plants showed enhanced resistance to the rice blast fungus. In this study, we identified OsWRKY53 as a substrate of OsMPK3/OsMPK6, components of a fungal PAMP-responsive MAPK cascade in rice, and analyzed the effect of OsWRKY53 phosphorylation on the regulation of basal defense responses to a virulence race of rice blast fungus Magnaporthe oryzae strain Ina86-137. An in vitro phosphorylation assay revealed that the OsMPK3/OsMPK6 activated by OsMKK4 phosphorylated OsWRKY53 recombinant protein at its multiple clustered serine-proline residues (SP cluster. When OsWRKY53 was coexpressed with a constitutively active mutant of OsMKK4 in a transient reporter gene assay, the enhanced transactivation activity of OsWRKY53 was found to be dependent on phosphorylation of the SP cluster. Transgenic rice plants overexpressing a phospho-mimic mutant of OsWRKY53 (OsWRKY53SD showed further-enhanced disease resistance to the blast fungus compared to native OsWRKY53-overexpressing rice plants, and a substantial number of defense-related genes, including pathogenesis-related protein genes, were more upregulated in the OsWRKY53SD-overexpressing plants compared to the OsWRKY53-overexpressing plants. These results strongly suggest that the OsMKK4-OsMPK3/OsMPK6 cascade regulates transactivation activity of OsWRKY53, and overexpression of the phospho-mimic mutant of OsWRKY53 results in a major change to the rice transcriptome at steady state that leads to activation of a defense response against the blast fungus in rice plants.

  12. Insecticide resistance may enhance the response to a host-plant volatile kairomone for the codling moth, Cydia pomonella (L.)

    Science.gov (United States)

    Sauphanor, Benoît; Franck, Pierre; Lasnier, Thérèse; Toubon, Jean-François; Beslay, Dominique; Boivin, Thomas; Bouvier, Jean-Charles; Renou, Michel

    2007-06-01

    The behavioral and electroantennographic responses of Cydia pomonella (L.) to the ripe pear volatile ethyl (2 E,4 Z)-2,4-decadienoate (Et- E, Z-DD), were compared in insecticide-susceptible and -resistant populations originating from southern France. A dose-response relationship to this kairomonal attractant was established for antennal activity and did not reveal differences between susceptible and resistant strains. Conversely, males of the laboratory strains expressing metabolic [cytochrome P450-dependent mixed-function oxidases (mfo)] or physiological (kdr-type mutation of the sodium-channel gene) resistance mechanisms exhibited a significantly higher response to Et- E, Z-DD than those of the susceptible strain in a wind tunnel experiment. No response of the females to this kairomone could be obtained in our wind-tunnel conditions. In apple orchards, mfo-resistant male moths were captured at significantly higher rates in kairomone-baited traps than in traps baited with the sex pheromone of C. pomonella. Such a differential phenomenon was not verified for the kdr-resistant insects, which exhibited a similar response to both the sex pheromone and the kairomonal attractant in apple orchards. Considering the widespread distribution of metabolic resistance in European populations of C. pomonella and the enhanced behavioral response to Et- E, Z-DD in resistant moths, the development of control measures based on this kairomonal compound would be of great interest for the management of insecticide resistance in this species.

  13. Voluntary resistance running with short distance enhances spatial memory related to hippocampal BDNF signaling.

    Science.gov (United States)

    Lee, Min Chul; Okamoto, Masahiro; Liu, Yu Fan; Inoue, Koshiro; Matsui, Takashi; Nogami, Haruo; Soya, Hideaki

    2012-10-15

    Although voluntary running has beneficial effects on hippocampal cognitive functions if done abundantly, it is still uncertain whether resistance running would be the same. For this purpose, voluntary resistance wheel running (RWR) with a load is a suitable model, since it allows increased work levels and resultant muscular adaptation in fast-twitch muscle. Here, we examined whether RWR would have potential effects on hippocampal cognitive functions with enhanced hippocampal brain-derived neurotrophic factor (BDNF), as does wheel running without a load (WR). Ten-week-old male Wistar rats were assigned randomly to sedentary (Sed), WR, and RWR (to a maximum load of 30% of body weight) groups for 4 wk. We found that in RWR, work levels increased with load, but running distance decreased by about half, which elicited muscular adaptation for fast-twitch plantaris muscle without causing any negative stress effects. Both RWR and WR led to improved spatial learning and memory as well as gene expressions of hippocampal BDNF signaling-related molecules. RWR increased hippocampal BDNF, tyrosine-related kinase B (TrkB), and cAMP response element-binding (CREB) protein levels, whereas WR increased only BDNF. With both exercise groups, there were correlations between spatial memory and BDNF protein (r = 0.41), p-CREB protein (r = 0.44), and work levels (r = 0.77). These results suggest that RWR plays a beneficial role in hippocampus-related cognitive functions associated with hippocampal BDNF signaling, even with short distances, and that work levels rather than running distance are more determinant of exercise-induced beneficial effects in wheel running with and without a load.

  14. Antibacterial Activity and Antibiotic-Enhancing Effects of Honeybee Venom against Methicillin-Resistant Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Sang Mi Han

    2016-01-01

    Full Text Available Methicillin-resistant Staphylococcus aureus (MRSA, along with other antibiotic resistant bacteria, has become a significant social and clinical problem. There is thus an urgent need to develop naturally bioactive compounds as alternatives to the few antibiotics that remain effective. Here we assessed the in vitro activities of bee venom (BV, alone or in combination with ampicillin, penicillin, gentamicin or vancomycin, on growth of MRSA strains. The antimicrobial activity of BV against MRSA strains was investigated using minimum inhibitory concentrations (MIC, minimum bactericidal concentrations (MBC and a time-kill assay. Expression of atl which encodes murein hydrolase, a peptidoglycan-degrading enzyme involved in cell separation, was measured by reverse transcription-polymerase chain reaction. The MICs of BV were 0.085 µg/mL and 0.11 µg/mL against MRSA CCARM 3366 and MRSA CCARM 3708, respectively. The MBC of BV against MRSA 3366 was 0.106 µg/mL and that against MRSA 3708 was 0.14 µg/mL. The bactericidal activity of BV corresponded to a decrease of at least 3 log CFU/g cells. The combination of BV with ampicillin or penicillin yielded an inhibitory concentration index ranging from 0.631 to 1.002, indicating a partial and indifferent synergistic effect. Compared to ampicillin or penicillin, both MRSA strains were more susceptible to the combination of BV with gentamicin or vancomycin. The expression of atl gene was increased in MRSA 3366 treated with BV. These results suggest that BV exhibited antibacterial activity and antibiotic-enhancing effects against MRSA strains. The atl gene was increased in MRSA exposed to BV, suggesting that cell division was interrupted. BV warrants further investigation as a natural antimicrobial agent and synergist of antibiotic activity.

  15. High carotenoids content can enhance resistance of selected Pinctada fucata families to high temperature stress.

    Science.gov (United States)

    Meng, Zihao; Zhang, Bo; Liu, Baosuo; Li, Haimei; Fan, Sigang; Yu, Dahui

    2017-02-01

    Carotenoids are a class of natural antioxidants widely found in aquatic, and they have significant effects on the growth, survival, and immunity of these organisms. To investigate the mechanisms of carotenoids in high temperature resistance, we observed the immune response of selected pearl oyster Pinctada fucata (Akoya pearl oyster) families with different carotenoids contents to high temperature stress. The results indicated that the survival rate (SR) of P. fucata decreased significantly with increase in temperature from 26 °C to 34 °C and with the decrease of total carotenoids content (TCC); when the TCC was higher, the SR tended to be higher. TCC and total antioxidant capacity (TAC) decreased significantly at 30 °C with increasing stress time. Correlation analysis indicated that TAC was positively and linearly correlated with TCC, and SR was S-type correlated with TCC and TAC. Immune analysis indicated that levels of superoxide dismutase (SOD), catalase (CAT), and malondialdehyde (MDA) in selected families (with higher TCC) under temperature stress (at 30 °C) were generally significantly lower than in the control group (with lowest TCC) and from 0 to 96 h, the levels of each of these substances varied significantly. Levels of SOD, CAT, and MDA within each family first rose from 0 to 3 h, then decreased to their lowest point after 24 h, and then rose again to their highest levels at 96 h. When TCC was higher, the levels of SOD, CAT, and MDA tended to be lower. These findings indicated that carotenoids play an important role in improving survival rates of P. fucata under high temperature stress by enhancing animals' antioxidant system, and could serve as an index for breeding stress-resistant lines in selective breeding practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Controlling the resistivity gradient in aluminum-doped zinc oxide grown by plasma-enhanced chemical vapor deposition

    NARCIS (Netherlands)

    Ponomarev, M.; Verheijen, M.A.; Keuning, W.; Sanden, van de M.C.M.; Creatore, M.

    2012-01-01

    Aluminum-doped ZnO (ZnO:Al) grown by chemical vapor deposition (CVD) generally exhibit a major drawback, i.e., a gradient in resistivity extending over a large range of film thickness. The present contribution addresses the plasma-enhanced CVD deposition of ZnO:Al layers by focusing on the control

  17. Chitosan and oligochitosan enhance ginger (Zingiber officinale Roscoe) resistance to rhizome rot caused by Fusarium oxysporum in storage

    Science.gov (United States)

    The ability of chitosan and oligochitosan to enhance the resistance of ginger (Zingiber officinale) to rhizome rot, caused by Fusarium oxysporum, in storage was investigated. Both chitosan and oligochitosan at 1 and 5 g/L significantly inhibited rhizome rot, relative to the untreated control, with...

  18. Utilizing genetic diversity in the desert watermelon citrullus colocynthis for enhancing watermelon cultivars for resistance to biotic and abiotic stress

    Science.gov (United States)

    Wide genetic diversity exists among the desert watermelon Citrullus colocynthis (L.) Schrad. (CC) accessions collected in the deserts of northern Africa, the Middle East, and Asia. Because of their resistance to biotic and abiotic stresses, there can be a viable source of genes used for enhancing wa...

  19. Simultaneous modification of three homoeologs of TaEDR1 by genome editing enhances powdery mildew resistance in wheat.

    Science.gov (United States)

    Zhang, Yunwei; Bai, Yang; Wu, Guangheng; Zou, Shenghao; Chen, Yongfang; Gao, Caixia; Tang, Dingzhong

    2017-08-01

    Wheat (Triticum aestivum L.) incurs significant yield losses from powdery mildew, a major fungal disease caused by Blumeria graminis f. sp. tritici (Bgt). enhanced disease resistance1 (EDR1) plays a negative role in the defense response against powdery mildew in Arabidopsis thaliana; however, the edr1 mutant does not show constitutively activated defense responses. This makes EDR1 an ideal target for approaches using new genome-editing tools to improve resistance to powdery mildew. We cloned TaEDR1 from hexaploid wheat and found high similarity among the three homoeologs of EDR1. Knock-down of TaEDR1 by virus-induced gene silencing or RNA interference enhanced resistance to powdery mildew, indicating that TaEDR1 negatively regulates powdery mildew resistance in wheat. We used CRISPR/Cas9 technology to generate Taedr1 wheat plants by simultaneous modification of the three homoeologs of wheat EDR1. No off-target mutations were detected in the Taedr1 mutant plants. The Taedr1 plants were resistant to powdery mildew and did not show mildew-induced cell death. Our study represents the successful generation of a potentially valuable trait using genome-editing technology in wheat and provides germplasm for disease resistance breeding. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  20. TaCPK2-A, a calcium-dependent protein kinase gene that is required for wheat powdery mildew resistance enhances bacterial blight resistance in transgenic rice.

    Science.gov (United States)

    Geng, Shuaifeng; Li, Aili; Tang, Lichuan; Yin, Lingjie; Wu, Liang; Lei, Cailin; Guo, Xiuping; Zhang, Xin; Jiang, Guanghuai; Zhai, Wenxue; Wei, Yuming; Zheng, Youliang; Lan, Xiujin; Mao, Long

    2013-08-01

    Calcium-dependent protein kinases (CPKs) are important Ca2+ signalling components involved in complex immune and stress signalling networks; but the knowledge of CPK gene functions in the hexaploid wheat is limited. Previously, TaCPK2 was shown to be inducible by powdery mildew (Blumeria graminis tritici, Bgt) infection in wheat. Here, its functions in disease resistance are characterized further. This study shows the presence of defence-response and cold-response cis-elements on the promoters of the A subgenome homoeologue (TaCPK2-A) and D subgenome homoeologue (TaCPK2-D), respectively. Their expression patterns were then confirmed by quantitative real-time PCR (qRT-PCR) using genome-specific primers, where TaCPK2-A was induced by Bgt treatment while TaCPK2-D mainly responded to cold treatment. Downregulation of TaCPK2-A by virus-induced gene silencing (VIGS) causes loss of resistance to Bgt in resistant wheat lines, indicating that TaCPK2-A is required for powdery mildew resistance. Furthermore, overexpression of TaCPK2-A in rice enhanced bacterial blight (Xanthomonas oryzae pv. oryzae, Xoo) resistance. qRT-PCR analysis showed that overexpression of TaCPK2-A in rice promoted the expression of OsWRKY45-1, a transcription factor involved in both fungal and bacterial resistance by regulating jasmonic acid and salicylic acid signalling genes. The opposite effect was found in wheat TaCPK2-A VIGS plants, where the homologue of OsWRKY45-1 was significantly repressed. These data suggest that modulation of WRKY45-1 and associated defence-response genes by CPK2 genes may be the common mechanism for multiple disease resistance in grass species, which may have undergone subfunctionalization in promoters before the formation of hexaploid wheat.

  1. CO2 fertilization and enhanced drought resistance in Greek firs from Cephalonia Island, Greece.

    Science.gov (United States)

    Koutavas, Athanasios

    2013-02-01

    Growth-climate relationships were investigated in Greek firs from Ainos Mountain on the island of Cephalonia in western Greece, using dendrochronology. The goal was to test whether tree growth is sensitive to moisture stress, whether such sensitivity has been stable through time, and whether changes in growth-moisture relationships support an influence of atmospheric CO2 on growth. Regressions of tree-ring indices (ad 1820-2007) with instrumental temperature, precipitation, and Palmer Drought Severity Index (PDSI) indicate that growth is fundamentally limited by growing-season moisture in late spring/early summer, most critically during June. However, this simple picture obscures a pattern of sharply evolving growth-climate relationships during the 20th century. Correlations between growth and June temperature, precipitation, and PDSI were significantly greater in the early 20th century but later degraded and disappeared. By the late 20th-early 21st century, there remains no statistically significant relationship between moisture and growth implying markedly enhanced resistance to drought. Moreover, growth experienced a net increase over the last half-century culminating with a sharp spike in ad 1988-1990. This recent growth acceleration is evident in the raw ring-width data prior to standardization, ruling out artifacts from statistical detrending. The vanishing relationship with moisture and parallel enhancement of growth are all the more notable because they occurred against a climatic backdrop of increasing aridity. The results are most consistent with a significant CO2 fertilization effect operating through restricted stomatal conductance and improved water-use efficiency. If this interpretation is correct, atmospheric CO2 is now overcompensating for growth declines anticipated from drier climate, suggesting its effect is unusually strong and likely to be detectable in other up-to-date tree-ring chronologies from the Mediterranean. © 2012 Blackwell Publishing

  2. Enhancing pharmacists' role in developing countries to overcome the challenge of antimicrobial resistance: a narrative review.

    Science.gov (United States)

    Sakeena, M H F; Bennett, Alexandra A; McLachlan, Andrew J

    2018-01-01

    Antimicrobial resistance (AMR) is a global health challenge and developing countries are more vulnerable to the adverse health impacts of AMR. Health care workers including pharmacists can play a key role to support the appropriate use of antimicrobials in developing countries and reduce AMR. The aim of this review is to investigate the role of pharmacists in the appropriate use of antibiotics and to identify how the pharmacists' role can be enhanced to combat AMR in developing countries. The databases MEDLINE, EMBASE, Web of Science and Google Scholar were searched for articles published between 2000 and the end of August 2017 that involved studies on the role of pharmacists in developing countries, the expanded services of pharmacists in patient care in developed countries and pharmacists' contributions in antimicrobial use in both developed and developing nations. In developing countries pharmacists role in patient care are relatively limited. However, in developed nations, the pharmacists' role has expanded to provide multifaceted services in patient care resulting in improved health outcomes from clinical services and reduced health care costs. Success stories of pharmacist-led programs in combating AMR demonstrates that appropriately trained pharmacists can be part of the solution to overcome the global challenge of AMR. Pharmacists can provide education to patients enabling them to use antibiotics appropriately. They can also provide guidance to their healthcare colleagues on appropriate antibiotic prescribing. This review highlights that appropriately trained pharmacists integrated into the health care system can make a significant impact in minimising inappropriate antibiotic use in developing countries. Strengthening and enhancing the pharmacists' role in developing countries has the potential to positively impact the global issue of AMR.

  3. Methodology development for plutonium categorization and enhancement of proliferation resistance by P3 mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Saito, M.; Kimura, Y.; Sagara, H.; Han, C. Y. [Tokyo Institute of Technology, Tokyo (Japan); Koyama, S. [Japan Atomic Energy Agency, Ibaraki (Japan)

    2012-03-15

    'Protected Plutonium Production (P3)' has been proposed to enhance the proliferation resistance of plutonium by the transmutation of Minor Actinides (MA). For example, adding the small amount of Minor Actinides such as {sup 237}Np or {sup 241}Am with large neutron capture cross-section to the uranium fuel to enhance the production of {sup 238}Pu, which has high spontaneous fission neutron rate do deteriorate the quality of the nuclear weapon manufacture and maintenance technologically difficult, is very effective for improving the isotopic barrier for the proliferation of plutonium. To demonstrate the P3 mechanism experimentally, U samples with 2, 5 and 10% {sup 237}Np doping were irradiated in Advanced Thermal Reactor (ATR) of INL. The fuel test samples were removed from the core at 100, 200 and 300 effective full power days (EFPD), and then post irradiation examination was completed at Chemical Lab. in Idaho National Laboratory(INL). The theoretical results of P3 mechanism predict the experimental ones quite well. The evaluation function, 'Attractiveness', was introduced as the ratio of function of Rossi-alpha to the 'Technical Difficulties for Fission Explosive Device Use. 'Rossi-alpha defined as the ratio of super-criticality to prompt neutron lifetime is the meaningful feature of the explosive yield. The Technical Difficulties for Fission Explosive Device Use can be expressed by the function of specific decay heat , spontaneous fission neutron rate and radiation of plutonium metal. Original methodology to evaluate Attractiveness of Plutonium has been improved by considering the effect of the compression of Plutonium isotope and also pre-detonation probability due to spontaneous fission neutron ate, which was applied for the categorization of the plutonium from the conventional reactors and the innovative reactors based on P3 mechanism. In the present paper, the fundamentals of P3 mechanism, the experimental demonstration of P3

  4. Methodology development for plutonium categorization and enhancement of proliferation resistance by P3 mechanism

    International Nuclear Information System (INIS)

    Saito, M.; Kimura, Y.; Sagara, H.; Han, C. Y.; Koyama, S.

    2012-01-01

    'Protected Plutonium Production (P3)' has been proposed to enhance the proliferation resistance of plutonium by the transmutation of Minor Actinides (MA). For example, adding the small amount of Minor Actinides such as 237 Np or 241 Am with large neutron capture cross-section to the uranium fuel to enhance the production of 238 Pu, which has high spontaneous fission neutron rate do deteriorate the quality of the nuclear weapon manufacture and maintenance technologically difficult, is very effective for improving the isotopic barrier for the proliferation of plutonium. To demonstrate the P3 mechanism experimentally, U samples with 2, 5 and 10% 237 Np doping were irradiated in Advanced Thermal Reactor (ATR) of INL. The fuel test samples were removed from the core at 100, 200 and 300 effective full power days (EFPD), and then post irradiation examination was completed at Chemical Lab. in Idaho National Laboratory(INL). The theoretical results of P3 mechanism predict the experimental ones quite well. The evaluation function, 'Attractiveness', was introduced as the ratio of function of Rossi-alpha to the 'Technical Difficulties for Fission Explosive Device Use. 'Rossi-alpha defined as the ratio of super-criticality to prompt neutron lifetime is the meaningful feature of the explosive yield. The Technical Difficulties for Fission Explosive Device Use can be expressed by the function of specific decay heat , spontaneous fission neutron rate and radiation of plutonium metal. Original methodology to evaluate Attractiveness of Plutonium has been improved by considering the effect of the compression of Plutonium isotope and also pre-detonation probability due to spontaneous fission neutron ate, which was applied for the categorization of the plutonium from the conventional reactors and the innovative reactors based on P3 mechanism. In the present paper, the fundamentals of P3 mechanism, the experimental demonstration of P3 mechanism in ATR of INL and the methodology

  5. A response regulator from a soil metagenome enhances resistance to the β-lactam antibiotic carbenicillin in Escherichia coli.

    Directory of Open Access Journals (Sweden)

    Heather K Allen

    Full Text Available Functional metagenomic analysis of soil metagenomes is a method for uncovering as-yet unidentified mechanisms for antibiotic resistance. Here we report an unconventional mode by which a response regulator derived from a soil metagenome confers resistance to the β-lactam antibiotic carbenicillin in Escherichia coli. A recombinant clone (βlr16 harboring a 5,169 bp DNA insert was selected from a metagenomic library previously constructed from a remote Alaskan soil. The βlr16 clone conferred specific resistance to carbenicillin, with limited increases in resistance to other tested antibiotics, including other β-lactams (penicillins and cephalosporins, rifampin, ciprofloxacin, erythromycin, chloramphenicol, nalidixic acid, fusidic acid, and gentamicin. Resistance was more pronounced at 24°C than at 37°C. Zone-of-inhibition assays suggested that the mechanism of carbenicillin resistance was not due to antibiotic inactivation. The DNA insert did not encode any genes known to confer antibiotic resistance, but did have two putative open reading frames (ORFs that were annotated as a metallopeptidase and a two-component response regulator. Transposon mutagenesis and subcloning of the two ORFs followed by phenotypic assays showed that the response regulator gene was necessary and sufficient to confer the resistance phenotype. Quantitative reverse transcriptase PCR showed that the response regulator suppressed expression of the ompF porin gene, independently of the small RNA regulator micF, and enhanced expression of the acrD, mdtA, and mdtB efflux pump genes. This work demonstrates that antibiotic resistance can be achieved by the modulation of gene regulation by heterologous DNA. Functional analyses such as these can be important for making discoveries in antibiotic resistance gene biology and ecology.

  6. Macrophage Resistance to HIV-1 Infection Is Enhanced by the Neuropeptides VIP and PACAP

    Science.gov (United States)

    Temerozo, Jairo R.; Joaquim, Rafael; Regis, Eduardo G.; Savino, Wilson; Bou-Habib, Dumith Chequer

    2013-01-01

    It is well established that host factors can modulate HIV-1 replication in macrophages, critical cells in the pathogenesis of HIV-1 infection due to their ability to continuously produce virus. The neuropeptides VIP and PACAP induce well-characterized effects on macrophages through binding to the G protein-coupled receptors VPAC1, VPAC2 and PAC1, but their influence on HIV-1 production by these cells has not been established. Here, we describe that VIP and PACAP reduce macrophage production of HIV-1, acting in a synergistic or additive manner to decrease viral growth. Using receptor antagonists, we detected that the HIV-1 inhibition promoted by VIP is dependent on its ligation to VPAC1/2, whereas PACAP decreases HIV-1 growth via activation of the VPAC1/2 and PAC1 receptors. Specific agonists of VPAC2 or PAC1 decrease macrophage production of HIV-1, whereas sole activation of VPAC1 enhances viral growth. However, the combination of specific agonists mimicking the receptor preference of the natural neuropeptides reproduces the ability of VIP and PACAP to increase macrophage resistance to HIV-1 replication. VIP and PACAP up-regulated macrophage secretion of the β-chemokines CCL3 and CCL5 and the cytokine IL-10, whose neutralization reversed the neuropeptide-induced inhibition of HIV-1 replication. Our results suggest that VIP and PACAP and the receptors VPAC2 and PAC1 could be used as targets for developing alternative therapeutic strategies for HIV-1 infection. PMID:23818986

  7. Overexpression of Soybean Isoflavone Reductase (GmIFR) Enhances Resistance to Phytophthora sojae in Soybean.

    Science.gov (United States)

    Cheng, Qun; Li, Ninghui; Dong, Lidong; Zhang, Dayong; Fan, Sujie; Jiang, Liangyu; Wang, Xin; Xu, Pengfei; Zhang, Shuzhen

    2015-01-01

    Isoflavone reductase (IFR) is an enzyme involved in the biosynthetic pathway of isoflavonoid phytoalexin in plants. IFRs are unique to the plant kingdom and are considered to have crucial roles in plant response to various biotic and abiotic environmental stresses. Here, we report the characterization of a novel member of the soybean isoflavone reductase gene family GmIFR. Overexpression of GmIFR transgenic soybean exhibited enhanced resistance to Phytophthora sojae. Following stress treatments, GmIFR was significantly induced by P. sojae, ethephon (ET), abscisic acid (placeCityABA), salicylic acid (SA). It is located in the cytoplasm when transiently expressed in soybean protoplasts. The daidzein levels reduced greatly for the seeds of transgenic plants, while the relative content of glyceollins in transgenic plants was significantly higher than that of non-transgenic plants. Furthermore, we found that the relative expression levels of reactive oxygen species (ROS) of transgenic soybean plants were significantly lower than those of non-transgenic plants after incubation with P. sojae, suggesting an important role of GmIFR might function as an antioxidant to reduce ROS in soybean. The enzyme activity assay suggested that GmIFR has isoflavone reductase activity.

  8. Enhanced resistance to both γ rays and neutrons in a Li-Fraumeni syndrome strain

    International Nuclear Information System (INIS)

    Gentner, N.E.; Smith, B.P.; Mirzayans, R.; Paterson, M.C.

    1985-01-01

    The authors have been investigating the radioresistance (RR) phenotype in a fibroblast strain derived from an affected member in a Li-Fraumeni syndrome family. The strain's D(10) value for acute exposure to Co-60 γ rays is 5.59+-0.42 Cy, compared to a composite value of 3.82+-0.09 Gy for normal controls. This difference is highly significant, giving a dose enhancement factor (DEF) of 1.46. The RR trait is independent of radiation quality in that the strain manifests the same degree of resistance (DEF=1.45) for high LET (14 MeV neutrons) radiation [D(10)=2.92 Gy, vs 2.01 Gy for ''normal'']. In contrast, the dose reduction factor for radiosensitive ataxia telangiectasia strains is diminished for 14 MeV neutrons (1.6) compared to γ rays (2.9), a finding consistent with a deficiency in DNA repair. In keeping with these combined data, the RR phenotype cannot be ascribed to a hyperactive repair process, since several conventional assays have yielded normal kinetics for the removal of radiogenic damage in the RR strain. Rather, its radioresistance may stem from a peculiar ability to ''buy more time'' for repair of non-coding lesions in DNA

  9. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Cijun Shuai

    2017-03-01

    Full Text Available Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  10. Biodegradation Resistance and Bioactivity of Hydroxyapatite Enhanced Mg-Zn Composites via Selective Laser Melting.

    Science.gov (United States)

    Shuai, Cijun; Zhou, Yuanzhuo; Yang, Youwen; Feng, Pei; Liu, Long; He, Chongxian; Zhao, Mingchun; Yang, Sheng; Gao, Chengde; Wu, Ping

    2017-03-17

    Mg-Zn alloys have attracted great attention as implant biomaterials due to their biodegradability and biomechanical compatibility. However, their clinical application was limited due to the too rapid degradation. In the study, hydroxyapatite (HA) was incorporated into Mg-Zn alloy via selective laser melting. Results showed that the degradation rate slowed down due to the decrease of grain size and the formation of protective layer of bone-like apatite. Moreover, the grain size continually decreased with increasing HA content, which was attributed to the heterogeneous nucleation and increased number of nucleation particles in the process of solidification. At the same time, the amount of bone-like apatite increased because HA could provide favorable areas for apatite nucleation. Besides, HA also enhanced the hardness due to the fine grain strengthening and second phase strengthening. However, some pores occurred owing to the agglomerate of HA when its content was excessive, which decreased the biodegradation resistance. These results demonstrated that the Mg-Zn/HA composites were potential implant biomaterials.

  11. Error-prone PCR mutation of Ls-EPSPS gene from Liriope spicata conferring to its enhanced glyphosate-resistance.

    Science.gov (United States)

    Mao, Chanjuan; Xie, Hongjie; Chen, Shiguo; Valverde, Bernal E; Qiang, Sheng

    2017-09-01

    Liriope spicata (Thunb.) Lour has a unique LsEPSPS structure contributing to the highest-ever-recognized natural glyphosate tolerance. The transformed LsEPSPS confers increased glyphosate resistance to E. coli and A. thaliana. However, the increased glyphosate-resistance level is not high enough to be of commercial value. Therefore, LsEPSPS was subjected to error-prone PCR to screen mutant EPSPS genes capable of endowing higher resistance levels. A mutant designated as ELs-EPSPS having five mutated amino acids (37Val, 67Asn, 277Ser, 351Gly and 422Gly) was selected for its ability to confer improved resistance to glyphosate. Expression of ELs-EPSPS in recombinant E. coli BL21 (DE3) strains enhanced resistance to glyphosate in comparison to both the LsEPSPS-transformed and -untransformed controls. Furthermore, transgenic ELs-EPSPS A. thaliana was about 5.4 fold and 2-fold resistance to glyphosate compared with the wild-type and the Ls-EPSPS-transgenic plants, respectively. Therefore, the mutated ELs-EPSPS gene has potential value for has potential for the development of glyphosate-resistant crops. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Enhancement of resistive switching properties in Al2O3 bilayer-based atomic switches: multilevel resistive switching

    Science.gov (United States)

    Vishwanath, Sujaya Kumar; Woo, Hyunsuk; Jeon, Sanghun

    2018-06-01

    Atomic switches are considered to be building blocks for future non-volatile data storage and internet of things. However, obtaining device structures capable of ultrahigh density data storage, high endurance, and long data retention, and more importantly, understanding the switching mechanisms are still a challenge for atomic switches. Here, we achieved improved resistive switching performance in a bilayer structure containing aluminum oxide, with an oxygen-deficient oxide as the top switching layer and stoichiometric oxide as the bottom switching layer, using atomic layer deposition. This bilayer device showed a high on/off ratio (105) with better endurance (∼2000 cycles) and longer data retention (104 s) than single-oxide layers. In addition, depending on the compliance current, the bilayer device could be operated in four different resistance states. Furthermore, the depth profiles of the hourglass-shaped conductive filament of the bilayer device was observed by conductive atomic force microscopy.

  13. Alpha-momorcharin enhances Tobacco mosaic virus resistance in tobaccoNN by manipulating jasmonic acid-salicylic acid crosstalk.

    Science.gov (United States)

    Yang, Ting; Zhu, Li-Sha; Meng, Yao; Lv, Rui; Zhou, Zhuo; Zhu, Lin; Lin, Hong-Hui; Xi, De-Hui

    2018-04-01

    Alpha-momorcharin (α-MMC) is a type-I ribosome inactivating protein (RIP) with a molecular weight of 29 kDa found in plants. This protein has been shown to be effective against a broad range of human viruses and also has anti-tumor activities. However, the mechanism by which α-MMC induces plant defense responses and regulates the N gene to promote resistance to the Tobacco mosaic virus (TMV) is still not clear. By using pharmacological and infection experiments, we found that α-MMC enhances TMV resistance of tobacco plants containing the N gene (tobacco NN ). Our results showed that plants pretreated with 0.5 mg/ml α-MMC could relieve TMV-induced oxidative damage, had enhanced the expression of the N gene and increased biosynthesis of jasmonic acid (JA) and salicylic acid (SA). Moreover, transcription of JA and SA signaling pathway genes were increased, and their expression persisted for a longer period of time in plants pretreated with α-MMC compared with those pretreated with water. Importantly, exogenous application of 1-Aminobenzotriazole (ABT, SA inhibitor) and ibuprofen (JA inhibitor) reduced α-MMC induced plant resistance under viral infection. Thus, our results revealed that α-MMC enhances TMV resistance of tobacco NN plants by manipulating JA-SA crosstalk. Copyright © 2017 Elsevier GmbH. All rights reserved.

  14. Connecting elements for wind power plants with an enhanced vibration resistance; Verbindungselemente fuer Windenergieanlagen mit erhoehter Schwingfestigkeit

    Energy Technology Data Exchange (ETDEWEB)

    Hasselmann, Uwe; Braun, Tobias [Peiner Umformtechnik GmbH, Peine (Germany)

    2010-07-01

    In wind power plants, large quantities of screws with large dimensions are used. This concerns to steel construction screws according to the regulations DIN EN 14399-4 or DASt 021. These screws are hot-galvanized. The wind power plants are exposed to large stochastic oscillation loads. Therefore, there exist fatigue proof procedures which follow a regulation from the construction sector (DIN EN 1993-1-9) and still are continued to specify in a certification guideline of the Germanic Lloyd. Within the range of mechanical engineering of wind power plants, a strength verification of the screwed joints follows the VDI regulation 2230. The vibration resistance of the screw is an input for the proof of vibration resistance. During the production of screws with an enhanced vibration resistance in the hot-galvanized condition one may dispense with the reducing coefficients for hot-galvanizing due to the technical measures. The use of connecting elements with enhanced vibration resistance enables the dimensioning of ring flange joints with less or smaller screws. This economically can be of advantage, since this positively affects the dimensions of the flange. In the borderline case with enhanced swinging loads the computational proof is enabled yet.

  15. Enhancing Docetaxel Delivery to Multidrug-Resistant Cancer Cells with Albumin-Coated Nanocrystals.

    Science.gov (United States)

    Gad, Sheryhan F; Park, Joonyoung; Park, Ji Eun; Fetih, Gihan N; Tous, Sozan S; Lee, Wooin; Yeo, Yoon

    2018-01-29

    Intravenous delivery of poorly water-soluble anticancer drugs such as docetaxel (DTX) is challenging due to the low bioavailability and the toxicity related to solubilizing excipients. Colloidal nanoparticles are used as alternative carriers, but low drug loading capacity and circulation instability limit their clinical translation. To address these challenges, DTX nanocrystals (NCs) were prepared using Pluronic F127 as an intermediate stabilizer and albumin as a functional surface modifier, which were previously found to be effective in producing small and stable NCs. We hypothesize that the albumin-coated DTX NCs (DTX-F-alb) will remain stable in serum-containing medium so as to effectively leverage the enhanced permeability and retention effect. In addition, the surface-bound albumin, in its native form, may contribute to cellular transport of NCs through interactions with albumin-binding proteins such as secreted protein acidic and rich in cysteine (SPARC). DTX-F-alb NCs showed sheet-like structure with an average length, width, and thickness of 284 ± 96, 173 ± 56, and 40 ± 8 nm and remained stable in 50% serum solution at a concentration greater than 10 μg/mL. Cytotoxicity and cellular uptake of DTX-F-alb and unformulated (free) DTX were compared on three cell lines with different levels of SPARC expression and DTX sensitivity. While the uptake of free DTX was highly dependent on DTX sensitivity, DTX-F-alb treatment resulted in relatively consistent cellular levels of DTX. Free DTX was more efficient in entering drug-sensitive B16F10 and SKOV-3 cells than DTX-F-alb, with consistent cytotoxic effects. In contrast, multidrug-resistant NCI/ADR-RES cells took up DTX-F-alb more than free DTX with time and responded better to the former. This difference was reduced by SPARC knockdown. The high SPARC expression level of NCI/ADR-RES cells, the known affinity of albumin for SPARC, and the opposing effect of SPARC knockdown support that DTX-F-alb have exploited the

  16. Stimulated phase-shift acoustic nanodroplets enhance vancomycin efficacy against methicillin-resistant Staphylococcus aureus biofilms

    Directory of Open Access Journals (Sweden)

    Guo H

    2017-06-01

    Full Text Available Hao Guo,1 Ziming Wang,1 Quanyin Du,1 Pan Li,2 Zhigang Wang,2 Aimin Wang1 1Department of Orthopedics, Institute of Surgery Research, Daping Hospital, Third Military Medical University, Chongqing, China; 2Chongqing Key Laboratory of Ultrasound Molecular Imaging, Institute of Ultrasound Imaging, Second Affiliated Hospital of Chongqing Medical University, Chongqing, China Purpose: Bacterial biofilms on the surface of prostheses are becoming a rising concern in managing prosthetic joint infections. The inherent resistant features of biofilms render traditional antimicrobial therapy unproductive and revision surgery outcomes uncertain. This situation has prompted the exploration of novel antimicrobial strategies. The synergy of ultrasound microbubbles and vancomycin has been proposed as an efficient alternative for biofilm eradication. The purpose of this study was to evaluate the anti-biofilm effect of stimulated phase-shift acoustic nanodroplets (NDs combined with vancomycin.Materials and methods: We fabricated lipid phase-shift NDs with a core of liquid perfluoropentane. A new phase change mode for NDs incorporating an initial unfocused low-intensity pulsed ultrasound for 5 minutes and a subsequent incubation at 37°C into a 24-hour duration was developed. Methicillin-resistant Staphylococcus aureus (MRSA biofilms were incubated with vancomycin and NDs under the hybrid stimulation. Biofilm morphology following treatment was determined using confocal laser scanning microscopy and scanning electron microscopy. Resazurin assay was used to quantify bactericidal efficacy against MRSA biofilm bacteria.Results: NDs treated sequentially with ultrasound and heating at 37°C achieved gradual and substantial ND vaporization and cavitation in a successive process. NDs after stimulation were capable of generating stronger destruction on biofilm structure which was best characterized by residual circular arc margins and more dead bacteria. Furthermore, NDs

  17. Enhanced mechanical properties and increased corrosion resistance of a biodegradable magnesium alloy by plasma electrolytic oxidation (PEO).

    Science.gov (United States)

    White, Leon; Koo, Youngmi; Neralla, Sudheer; Sankar, Jagannathan; Yun, Yeoheung

    2016-06-01

    We report the enhanced mechanical properties of AZ31 magnesium alloys by plasma electrolytic oxidation (PEO) coating in NaOH, Na 2 SiO 3 , KF and NaH 2 PO 4 ·2H 2 O containing electrolytes. Mechanical properties including wear resistance, surface hardness and elastic modulus were increased for PEO-coated AZ31 Mg alloys (PEO-AZ31). DC polarization in Hank's solution indicating that the corrosion resistance significantly increased for PEO-coating in KF-contained electrolyte. Based on these results, the PEO coating method shows promising potential for use in biodegradable implant applications where tunable corrosion and mechanical properties are needed.

  18. Insulin Resistance in PCOS Patients Enhances Oxidative Stress and Leukocyte Adhesion: Role of Myeloperoxidase

    Science.gov (United States)

    Victor, Victor M.; Rovira-Llopis, Susana; Bañuls, Celia; Diaz-Morales, Noelia; Martinez de Marañon, Arantxa; Rios-Navarro, Cesar; Alvarez, Angeles; Gomez, Marcelino; Rocha, Milagros; Hernández-Mijares, Antonio

    2016-01-01

    Cardiovascular diseases and oxidative stress are related to polycystic ovary syndrome (PCOS) and insulin resistance (IR). We have evaluated the relationship between myeloperoxidase (MPO) and leukocyte activation in PCOS patients according to homeostatic model assessment of IR (HOMA-IR), and have explored a possible correlation between these factors and endocrine and inflammatory parameters. This was a prospective controlled study conducted in an academic medical center. The study population consisted of 101 PCOS subjects and 105 control subjects. We divided PCOS subjects into PCOS non-IR (HOMA-IRPCOS IR (HOMA-IR>2.5). Metabolic and anthropometric parameters, total and mitochondrial reactive oxygen species (ROS) production, MPO levels, interactions between human umbilical vein endothelial cells and leukocytes, adhesion molecules (E-selectin, ICAM-1 and VCAM-1) and proinflammatory cytokines (IL-6 and TNF-α) were evaluated. Oxidative stress was observed in PCOS patients, in whom there was an increase in total and mitochondrial ROS production and MPO levels. Enhanced rolling flux and adhesion, and a decrease in polymorphonuclear cell rolling velocity were also detected in PCOS subjects. Increases in IL-6 and TNF-α and adhesion molecules (E-selectin, ICAM-1 and VCAM-1) were also observed, particularly in the PCOS IR group, providing evidence that inflammation and oxidative stress are related in PCOS patients. HOMA-IR was positively correlated with hsCRP (pPCOS patients in general, and particularly in those with IR. Inflammation in PCOS induces leukocyte-endothelium interactions and a simultaneous increase in IL-6, TNF-α, E-selectin, ICAM-1 and VCAM-1. These conditions are aggravated by the presence of IR. PMID:27007571

  19. Can an egg-dropping race enhance students' conceptual understanding of air resistance?

    Science.gov (United States)

    Lee, Yeung Chung; Kwok, Ping Wai

    2009-03-01

    Children are familiar with situations in which air resistance plays an important role, such as parachuting. However, it is not known whether they have any understanding about the concept of air resistance, how air resistance affects falling objects, and the differential effect it has on different objects. The literature reveals that there are misconceptions even among undergraduate physics students about how air resistance is affected by the mass and size of falling objects. A study was carried out in Hong Kong to explore Grade 6 students' (aged 11-12) conceptions of air resistance with respect to falling objects of different size and mass, and whether the subjects showed any change in their conceptual understanding after participating in an egg-dropping race. The findings show that students had a wide range of conceptions, which could be characterized into different levels. Their conceptions seem rather robust, and more structured interventions are required to bring about changes in students' conceptual understanding of air resistance.

  20. Bulgecin A as a β-lactam enhancer for carbapenem-resistant Pseudomonas aeruginosa and carbapenem-resistant Acinetobacter baumannii clinical isolates containing various resistance mechanisms.

    Science.gov (United States)

    Skalweit, Marion J; Li, Mei

    2016-01-01

    Genetic screening of Pseudomonas aeruginosa (PSDA) and Acinetobacter baumannii (ACB) reveals genes that confer increased susceptibility to β-lactams when disrupted, suggesting novel drug targets. One such target is lytic transglycosylase. Bulgecin A (BlgA) is a natural product of Pseudomonas mesoacidophila and a lytic transglycosolase inhibitor that works synergistically with β-lactams targeting PBP3 for Enterobacteriaceae. BlgA also weakly inhibits di-Zn 2+ metallo-β-lactamases like L1 of Stenotrophomonas maltophilia . We hypothesized that because of its unique mechanism of action, BlgA could restore susceptibility to carbapenems in carbapenem-resistant PSDA (CR-PSDA) and carbapenem-resistant ACB, as well as ACB resistant to sulbactam. A BlgA-containing extract was prepared using a previously published protocol. CR-PSDA clinical isolates demonstrating a variety of carbapenem resistance mechanisms (VIM-2 carbapenemases, efflux mechanisms, and AmpC producer expression) were characterized with agar dilution minimum inhibitory concentration (MIC) testing and polymerase chain reaction. Growth curves using these strains were prepared using meropenem, BlgA extract, and meropenem plus BlgA extract. A concentrated Blg A extract combined with low concentrations of meropenem, was able to inhibit the growth of clinical strains of CR-PSDA for strains that had meropenem MICs ≥8 mg/L by agar dilution, and a clinical strain of an OXA-24 producing ACB that had a meropenem MIC >32 mg/L and intermediate ampicillin/sulbactam susceptibility. Similar experiments were conducted on a TEM-1 producing ACB strain resistant to sulbactam. BlgA with ampicillin/sulbactam inhibited the growth of this organism. As in Enterobacteriaceae, BlgA appears to restore the efficacy of meropenem in suppressing the growth of CR-PSDA and carbapenem-resistant ACB strains with a variety of common carbapenem resistance mechanisms. BlgA extract also inhibits VIM-2 β-lactamase in vitro. BlgA may prove to be

  1. Enhanced mechanical properties and increased corrosion resistance of a biodegradable magnesium alloy by plasma electrolytic oxidation (PEO)

    International Nuclear Information System (INIS)

    White, Leon; Koo, Youngmi; Neralla, Sudheer; Sankar, Jagannathan; Yun, Yeoheung

    2016-01-01

    Highlights: • Plasma electrolytic oxidation (PEO) method was developed to control corrosion, porosity, and mechanical property. • Mechanical properties of PEO-coated AZ31 alloys were affected by the different electrolyte. • Mechanical properties and corrosion resistance of PEO-coated AZ31 alloys were compared with uncoated one. - Abstract: We report the enhanced mechanical properties of AZ31 magnesium alloys by plasma electrolytic oxidation (PEO) coating in NaOH, Na_2SiO_3, KF and NaH_2PO_4·2H_2O containing electrolytes. Mechanical properties including wear resistance, surface hardness and elastic modulus were increased for PEO-coated AZ31 Mg alloys (PEO-AZ31). DC polarization in Hank's solution indicating that the corrosion resistance significantly increased for PEO-coating in KF-contained electrolyte. Based on these results, the PEO coating method shows promising potential for use in biodegradable implant applications where tunable corrosion and mechanical properties are needed.

  2. UV Enhanced Oxygen Response Resistance Ratio of ZnO Prepared by Thermally Oxidized Zn on Sapphire Substrate

    Directory of Open Access Journals (Sweden)

    Cheng-Chang Yu

    2013-01-01

    Full Text Available ZnO thin film was fabricated by thermally oxidized Zn at 600°C for 1 h. A surface containing nanostructured dumbbell and lines was observed by scanning electron microscope (SEM. The ZnO resistor device was formed after the following Ti/Au metallization. The device resistance was characterized at different oxygen pressure environment in the dark and under ultraviolet (UV light illumination coming from the mercury lamp with a short pass filter. The resistance increases with the increase of oxygen pressure. The resistance decreases and response increases with the increase of light intensity. Models considering the barrier height variation caused by the adsorbed oxygen related species were used to explain these results. The UV light illumination technology shows an effective method to enhance the detection response for this ZnO resistor oxygen sensor.

  3. Mutation in Rice Abscisic Acid2 Results in Cell Death, Enhanced Disease-Resistance, Altered Seed Dormancy and Development

    Directory of Open Access Journals (Sweden)

    Yongxiang Liao

    2018-03-01

    Full Text Available Lesion mimic mutants display spontaneous cell death, and thus are valuable for understanding the molecular mechanism of cell death and disease resistance. Although a lot of such mutants have been characterized in rice, the relationship between lesion formation and abscisic acid (ABA synthesis pathway is not reported. In the present study, we identified a rice mutant, lesion mimic mutant 9150 (lmm9150, exhibiting spontaneous cell death, pre-harvest sprouting, enhanced growth, and resistance to rice bacterial and blast diseases. Cell death in the mutant was accompanied with excessive accumulation of H2O2. Enhanced disease resistance was associated with cell death and upregulation of defense-related genes. Map-based cloning identified a G-to-A point mutation resulting in a D-to-N substitution at the amino acid position 110 of OsABA2 (LOC_Os03g59610 in lmm9150. Knock-out of OsABA2 through CRISPR/Cas9 led to phenotypes similar to those of lmm9150. Consistent with the function of OsABA2 in ABA biosynthesis, ABA level in the lmm9150 mutant was significantly reduced. Moreover, exogenous application of ABA could rescue all the mutant phenotypes of lmm9150. Taken together, our data linked ABA deficiency to cell death and provided insight into the role of ABA in rice disease resistance.

  4. Mutation in Rice Abscisic Acid2 Results in Cell Death, Enhanced Disease-Resistance, Altered Seed Dormancy and Development.

    Science.gov (United States)

    Liao, Yongxiang; Bai, Que; Xu, Peizhou; Wu, Tingkai; Guo, Daiming; Peng, Yongbin; Zhang, Hongyu; Deng, Xiaoshu; Chen, Xiaoqiong; Luo, Ming; Ali, Asif; Wang, Wenming; Wu, Xianjun

    2018-01-01

    Lesion mimic mutants display spontaneous cell death, and thus are valuable for understanding the molecular mechanism of cell death and disease resistance. Although a lot of such mutants have been characterized in rice, the relationship between lesion formation and abscisic acid (ABA) synthesis pathway is not reported. In the present study, we identified a rice mutant, lesion mimic mutant 9150 ( lmm9150 ), exhibiting spontaneous cell death, pre-harvest sprouting, enhanced growth, and resistance to rice bacterial and blast diseases. Cell death in the mutant was accompanied with excessive accumulation of H 2 O 2 . Enhanced disease resistance was associated with cell death and upregulation of defense-related genes. Map-based cloning identified a G-to-A point mutation resulting in a D-to-N substitution at the amino acid position 110 of OsABA2 (LOC_Os03g59610) in lmm9150 . Knock-out of OsABA2 through CRISPR/Cas9 led to phenotypes similar to those of lmm9150 . Consistent with the function of OsABA2 in ABA biosynthesis, ABA level in the lmm9150 mutant was significantly reduced. Moreover, exogenous application of ABA could rescue all the mutant phenotypes of lmm9150 . Taken together, our data linked ABA deficiency to cell death and provided insight into the role of ABA in rice disease resistance.

  5. Cefditoren and ceftriaxone enhance complement-mediated immunity in the presence of specific antibodies against antibiotic-resistant pneumococcal strains.

    Directory of Open Access Journals (Sweden)

    Elisa Ramos-Sevillano

    Full Text Available BACKGROUND: Specific antibodies mediate humoral and cellular protection against invading pathogens such as Streptococcus pneumoniae by activating complement mediated immunity, promoting phagocytosis and stimulating bacterial clearance. The emergence of pneumococcal strains with high levels of antibiotic resistance is of great concern worldwide and a serious threat for public health. METHODOLOGY/PRINCIPAL FINDINGS: Flow cytometry was used to determine whether complement-mediated immunity against three antibiotic-resistant S. pneumoniae clinical isolates is enhanced in the presence of sub-inhibitory concentrations of cefditoren and ceftriaxone. The binding of acute phase proteins such as C-reactive protein and serum amyloid P component, and of complement component C1q, to pneumococci was enhanced in the presence of serum plus either of these antibiotics. Both antibiotics therefore trigger the activation of the classical complement pathway against S. pneumoniae. C3b deposition was also increased in the presence of specific anti-pneumococcal antibodies and sub-inhibitory concentrations of cefditoren and ceftriaxone confirming that the presence of these antibiotics enhances complement-mediated immunity to S. pneumoniae. CONCLUSIONS/SIGNIFICANCE: Using cefditoren and ceftriaxone to promote the binding of acute phase proteins and C1q to pneumococci, and to increase C3b deposition, when anti-pneumococcal antibodies are present, might help reduce the impact of antibiotic resistance in S. pneumoniae infections.

  6. Enhanced radiation resistance through interface modification of nano-structured steels for Gen IV in-core applications

    International Nuclear Information System (INIS)

    Jang, Jinsung; Kang, Suk Hoon; Kim, Min Chul

    2013-06-01

    This project is to increase radiation tolerance of candidate alloys for Gen IV core component through the optimization of grain size and grain boundary characteristics. The focus is on nanocrystalline metal alloys with a fcc crystal structure. The long-term goal is to design and develop bulk nanostructured austenitic steels with enhanced void swelling resistance and substantial ductility, and to enhance their creep resistance at elevated temperatures via grain boundary engineering. An austenitic stainless steel, HT-UPS (high temperature ultra-fine precipitates strengthened) was developed at ORNL, and is expected to show enhanced void swelling resistance through the trapping of point defects at nanometer-sized carbides. Reducing the grain size and increasing the fraction-induced point defects (due to the increased sink area of the grain boundaries), to make bubble nucleation at the boundaries less likely (by reducing the fraction of high-energy boundaries), and to improve the strength and ductility under radiation by producing a higher density of nanometer sized carbides on the boundaries

  7. Emancipatory Sexuality Education and Sexual Assault Resistance: Does the Former Enhance the Latter?

    Science.gov (United States)

    Senn, Charlene Y.; Gee, Stephanie S.; Thake, Jennifer

    2011-01-01

    The current study examined whether adding emancipatory sexuality education, which encourages the exploration of women's own sexual values and desires, to a sexual assault resistance program would improve women's resistance to sexual assault by known men. The participants were 214 first-year university students. A randomized experimental design…

  8. Enhanced Earthquake-Resistance on the High Level Radioactive Waste Canister

    International Nuclear Information System (INIS)

    Choi, Youngchul; Yoon, Chanhoon; Lee, Jeaowan; Kim, Jinsup; Choi, Heuijoo

    2014-01-01

    In this paper, the earthquake-resistance type buffer was developed with the method protecting safely about the earthquake. The main parameter having an effect on the earthquake-resistant performance was analyzed and the earthquake-proof type buffer material was designed. The shear analysis model was developed and the performance of the earthquake-resistance buffer material was evaluated. The dynamic behavior of the radioactive waste disposal canister was analyzed in case the earthquake was generated. In the case, the disposal canister gets the serious damage. In this paper, the earthquake-resistance buffer material was developed in order to prevent this damage. By putting the buffer in which the density is small between the canister and buffer, the earthquake-resistant performance was improved about 80%

  9. Enhanced resistive switching in forming-free graphene oxide films embedded with gold nanoparticles deposited by electrophoresis

    International Nuclear Information System (INIS)

    Khurana, Geetika; Kumar, Nitu; Katiyar, Ram S; Misra, Pankaj; Kooriyattil, Sudheendran; Scott, James F

    2016-01-01

    Forming-free resistive random access memory (ReRAM) devices having low switching voltages are a prerequisite for their commercial applications. In this study, the forming-free resistive switching characteristics of graphene oxide (GO) films embedded with gold nanoparticles (Au Nps), having an enhanced on/off ratio at very low switching voltages, were investigated for non-volatile memories. The GOAu films were deposited by the electrophoresis method and as-grown films were found to be in the low resistance state; therefore no forming voltage was required to activate the devices for switching. The devices having an enlarged on/off ratio window of ∼10"6 between two resistance states at low voltages (<1 V) for repetitive dc voltage sweeps showed excellent properties of endurance and retention. In these films Au Nps were uniformly dispersed over a large area that provided charge traps, which resulted in improved switching characteristics. Capacitance was also found to increase by a factor of ∼10, when comparing high and low resistance states in GOAu and pristine GO devices. Charge trapping and de-trapping by Au Nps was the mechanism responsible for the improved switching characteristics in the films. (paper)

  10. Heterologous Expression of the Cotton NBS-LRR Gene GbaNA1 Enhances Verticillium Wilt Resistance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Nan-Yang Li

    2018-02-01

    Full Text Available Verticillium wilt caused by Verticillium dahliae results in severe losses in cotton, and is economically the most destructive disease of this crop. Improving genetic resistance is the cleanest and least expensive option to manage Verticillium wilt. Previously, we identified the island cotton NBS-LRR-encoding gene GbaNA1 that confers resistance to the highly virulent V. dahliae isolate Vd991. In this study, we expressed cotton GbaNA1 in the heterologous system of Arabidopsis thaliana and investigated the defense response mediated by GbaNA1 following inoculations with V. dahliae. Heterologous expression of GbaNA1 conferred Verticillium wilt resistance in A. thaliana. Moreover, overexpression of GbaNA1 enabled recovery of the resistance phenotype of A. thaliana mutants that had lost the function of GbaNA1 ortholog gene. Investigations of the defense response in A. thaliana showed that the reactive oxygen species (ROS production and the expression of genes associated with the ethylene signaling pathway were enhanced significantly following overexpression of GbaNA1. Intriguingly, overexpression of the GbaNA1 ortholog from Gossypium hirsutum (GhNA1 in A. thaliana did not induce the defense response of ROS production due to the premature termination of GhNA1, which lacks the encoded NB-ARC and LRR motifs. GbaNA1 therefore confers Verticillium wilt resistance in A. thaliana by the activation of ROS production and ethylene signaling. These results demonstrate the functional conservation of the NBS-LRR-encoding GbaNA1 in a heterologous system, and the mechanism of this resistance, both of which may prove valuable in incorporating GbaNA1-mediated resistance into other plant species.

  11. CTGF enhances resistance to 5-FU-mediating cell apoptosis through FAK/MEK/ERK signal pathway in colorectal cancer

    Directory of Open Access Journals (Sweden)

    Yang K

    2016-11-01

    Full Text Available Kai Yang, Kai Gao, Gui Hu, Yanguang Wen, Changwei Lin, Xiaorong Li Department of General Surgery, The Third Affiliated Hospital of Central South University, Central South University, Changsha, Hunan, People’s Republic of China Abstract: Colorectal cancer (CRC is one of the most commonly diagnosed cancers among both males and females; the chemotherapy drug 5-fluorouracil (5-FU is one of a doctors’ first lines of defense against CRC. However, therapeutic failures are common because of the emergence of drug resistance. Connective tissue growth factor (CTGF is a secreted protein that binds to integrins, and regulates the invasiveness and metastasis of certain carcinoma cells. Here, we found that CTGF was upregulated in drug-resistant phenotype of human CRC cells. Overexpression of CTGF enhanced the resistance to 5-FU-induced cell apoptosis. Moreover, downregulating the expression of CTGF promoted the curative effect of chemotherapy and blocked the cell cycle in the G1 phase. We also found that CTGF facilitated resistance to 5-FU-induced apoptosis by increasing the expression of B-cell lymphoma-extra large (Bcl-xL and survivin. Then we pharmacologically blocked MEK/ERK signal pathway and assessed 5-FU response by MTT assays. Our current results indicate that the expression of phosphorylated forms of MEK/ERK increased in high CTGF expression cells and MEK inhibited increases in 5-FU-mediated apoptosis of resistant CRC cells. Therefore, our data suggest that MEK/ERK signaling contributes to 5-FU resistance through upstream of CTGF, and supports CRC cell growth. Comprehending the molecular mechanism underlying 5-FU resistance may ultimately aid the fight against CRC. Keywords: connective tissue growth factor, 5-fluorouracil, mitogen-activated protein kinase/extracellular regulated protein kinases, phosphatidyl inositol 3-kinase/serine/threonine kinase Akt, colorectal cancer

  12. Polyelectrolyte Multicomponent Colloidosomes Loaded with Nisin Z for Enhanced Antimicrobial Activity against Foodborne Resistant Pathogens

    Directory of Open Access Journals (Sweden)

    Taskeen Niaz

    2018-01-01

    Full Text Available Food grade micro- or nano-carrier systems (NCS are being developed to improve the controlled release of antimicrobial agents. To augment the stability of liposomal NCS and to overcome the limitations associated with the use of free bacteriocin (nisin in the food system, multi-component colloidosomes (MCCS were developed by electrostatic interactions between anionic alginate and cationic chitosan (multilayer around phospholipids based liposomes (core. Zeta-sizer results revealed the average diameter of 145 ± 2 nm, 596 ± 3 nm, and 643 ± 5 nm for nano-liposome (NL, chitosomes (chitosan coated NL and MCCS, respectively. Zeta potential values of NCS varied from −4.37 ± 0.16 mV to 33.3 ± 6 mV, thus both chitosomes (CS and MCCS were positively charged. Microstructure analysis by scanning electron microscope (SEM revealed relatively higher size of MCCS with smooth and round morphology. TGA and DSC based experiments revealed that MCCS were thermally more stable than uncoated liposomes. Encapsulation efficiency of nisin in MCCS was observed to be 82.9 ± 4.1%, which was significantly higher than NL (56.5 ± 2.5%. FTIR analyses confirmed the cross-linking between sodium alginate and chitosan layer. Both qualitative (growth kinetics and quantitative (colony forming unit antimicrobial assays revealed that nisin loaded MCCS have superior potential to control resistant foodborne pathogens including Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis, (5.8, 5.4, and 6.1 Log CFUmL−1 reduction, respectively as compared to free nisin, loaded NL or CS. Controlled release kinetics data fitted with Korsmeyer–Peppas model suggested that nisin release from MCCS followed Fickian diffusion. Cytotoxic studies on human blood cells and HepG2 cell lines revealed hemocompatibility and non-toxicity of MCCS. Thus, due to enhanced controlled release, stability and biocompatibility; these multi-component colloidosomes can be useful for

  13. Novel oral administrated paclitaxel micelles with enhanced bioavailability and antitumor efficacy for resistant breast cancer.

    Science.gov (United States)

    Zhang, Ting; Luo, Jingwen; Fu, Yao; Li, Hanmei; Ding, Rui; Gong, Tao; Zhang, Zhirong

    2017-02-01

    Paclitaxel (PTX) is a widely used antineoplastic drug in clinic. Due to poor aqueous solubility, it is administrated by intravenous infusion of cremophor EL containing formulation with serious adverse effects. The low oral bioavailability is a great challenge for oral formulation development. In addition, P-gp mediated multidrug resistance limit its clinical use in various resistant cancers. In this study, a novel super-antiresistant PTX micelle formulation for oral administration was developed. A P-gp inhibitor, bromotetrandrine (W198) was co-encapsulated in the micelle. The micelles were composed of Solutol HS 15 and d-a-tocopheryl polyethylene glycol succinate to avoid Cremophor EL induced toxicity. The micelles were round with a mean particle size of ∼13nm and an encapsulation efficiency of ∼90%. A series of in vitro evaluations were performed in non-resistant MCF-7 cells and resistant MCF-7/Adr cells. The super-antiresistant PTX micelles showed higher cell uptake efficiency, significantly increased cytotoxicity and antimitotic effect in drug resistant MCF-7/Adr cells when compared with Taxol and other PTX micelle formulations. Compared with Taxol, the super-antiresistant PTX micelles significantly improved bioavailability after oral administration in rats, and inhibited tumor growth in multidrug resistance xenografted MCF-7/Adr nude mice. In summary, the noval super-antiresistant PTX micelles showed a great potential for oral delivery of PTX against resistant breast cancer. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Fabrication of Nanostructures on Implantable Biomaterials for Biocompatibility Enhancement and Infection Resistance

    Science.gov (United States)

    Liu, Luting

    An implant or implantable medical device, which is used to replace or restore the function of traumatized or degenerated tissues or organs, or acts as a fraction of or the whole biological structure, has been used in many different parts of the body for various applications (such as orthopedics, cardiovascular stents, or drug delivery systems for medical treatment). The best performance of the vast majority of implants is achieved when the biomaterial used promotes some biological activity (such as bone regeneration) while minimizing undesirable activity (such as infection, one of the most common reasons for the failure of many implants). The surface of the implant, through its interactions with proteins, bacteria and tissue forming cells, plays a critical role in the success or failure of the implant. Therefore, in this study, we sought to employ various nanofabrication techniques for tailoring implant surfaces to minimize bacteria and promote mammalian cell functions without using drugs. Titanium (Ti) and polyetheretherketone (PEEK) are commonly used biomaterials in orthopedic implants. Further surface modification is needed to support osseointegration while inhibiting bacteria attachment. Herein, temperature controlled atomic layer deposition (ALD) was utilized to provide unique nanostructured TiO2 coatings on commercial Ti. In vitro bacteria experiments revealed that the nano-TiO2 coatings showed promising antimicrobial efficacy towards Gram-positive bacteria (S. aureus), Gram-negative bacteria (E. coli) and antibiotic-resistant bacteria ( MRSA). Impressively, cell results indicated that this nano-TiO 2 coating stimulated osteoblast (or bone forming cell) adhesion and proliferation while suppressing undesirable fibroblast functions. The same procedure was performed on PEEK and also resulted in enhanced osteoblast functions and produced antimicrobial properties. In another study, to isolate the effect of surface chemistry on cell and bacteria activities, a

  15. RNA-Seq analysis reveals insight into enhanced rice Xa7-mediated bacterial blight resistance at high temperature.

    Directory of Open Access Journals (Sweden)

    Stephen P Cohen

    Full Text Available Plant disease is a major challenge to agriculture worldwide, and it is exacerbated by abiotic environmental factors. During some plant-pathogen interactions, heat stress allows pathogens to overcome host resistance, a phenomenon which could severely impact crop productivity considering the global warming trends associated with climate change. Despite the importance of this phenomenon, little is known about the underlying molecular mechanisms. To better understand host plant responses during simultaneous heat and pathogen stress, we conducted a transcriptomics experiment for rice plants (cultivar IRBB61 containing Xa7, a bacterial blight disease resistance (R gene, that were infected with Xanthomonas oryzae, the bacterial blight pathogen of rice, during high temperature stress. Xa7-mediated resistance is unusual relative to resistance mediated by other R genes in that it functions better at high temperatures. Using RNA-Seq technology, we identified 8,499 differentially expressed genes as temperature responsive in rice cultivar IRBB61 experiencing susceptible and resistant interactions across three time points. Notably, genes in the plant hormone abscisic acid biosynthesis and response pathways were up-regulated by high temperature in both mock-treated plants and plants experiencing a susceptible interaction and were suppressed by high temperature in plants exhibiting Xa7-mediated resistance. Genes responsive to salicylic acid, an important plant hormone for disease resistance, were down-regulated by high temperature during both the susceptible and resistant interactions, suggesting that enhanced Xa7-mediated resistance at high temperature is not dependent on salicylic acid signaling. A DNA sequence motif similar to known abscisic acid-responsive cis-regulatory elements was identified in the promoter region upstream of genes up-regulated in susceptible but down-regulated in resistant interactions. The results of our study suggest that the plant

  16. Enhanced corrosion resistance and biocompatibility of β-type Ti–25Nb–25Zr alloy by electrochemical anodization

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Her-Hsiung [Department of Dentistry, National Yang-Ming University, Taipei, 112 Taiwan (China); Graduate Institute of Basic Medical Science, China Medical University, Taichung, 404 Taiwan (China); Department of Biomedical Informatics, Asia University, Taichung, 413 Taiwan (China); Department of Stomatology, Taipei Veterans General Hospital, Taipei, 112 Taiwan (China); Wu, Chia-Ping; Sun, Ying-Sui; Huang, Hsun-Miao [Institute of Oral Biology, National Yang-Ming University, Taipei, 112 Taiwan (China); Lee, Tzu-Hsin, E-mail: biomaterials@hotmail.com [School of Dentistry, Chung Shan Medical University, Taichung, 402 Taiwan (China); Oral Medicine Center, Chung Shan Medical University Hospital, Taichung, 402 Taiwan (China)

    2013-12-31

    The biocompatibility of implants is largely determined by their surface characteristics. This study presents a novel method for performing electrochemical anodization on β-type Ti–25Nb–25Zr alloy with a low elastic modulus (approximately 70 GPa). This method results in a thin hybrid layer capable of enhancing the surface characteristics of the implants. We investigated the surface topography and microstructure of the resulting Ti–25Nb–25Zr alloy. The corrosion resistance was evaluated using potentiodynamic polarization curve measurements in simulated body fluid. The cytotoxicity was evaluated according to International Organization for Standardization 10993–5 specification. Cell adhesion of human bone marrow mesenchymal stem cells on the test specimens was observed using scanning electron microscopy and fluorescence microscopy. The anodization produced a thin (approximately 40 nm-thick) hybrid oxide layer with a nanoporous outer sublayer (pore size < 15 nm) and a dense inner layer. The thin hybrid oxide layer increased the corrosion resistance of the Ti–25Nb–25Zr alloy by increasing the corrosion potential and decreasing both the corrosion rate and passive current. Ti–25Nb–25Zr alloys with and without anodization treatment were non-toxic. Surface nanotopography on the anodized Ti–25Nb–25Zr alloy enhanced protein adsorption and cell adhesion. Our results demonstrate that electrochemical anodization increases the corrosion resistance and cell adhesion of β-type Ti–25Nb–25Zr alloy while providing a lower elastic modulus suitable for implant applications. - Highlights: • An electrochemical anodization was applied to β-type Ti–25Nb–25Zr alloy surface. • Anodized surface had nanoscale hybrid oxide layer. • Anodized surface increased corrosion resistance due to dense inner sublayer. • Anodized surface enhanced cell adhesion due to nanoporous outer sublayer. • Electrochemical anodization has potential as implant surface treatment.

  17. Whey Protein Supplementation Enhances Whole Body Protein Metabolism and Performance Recovery after Resistance Exercise: A Double-Blind Crossover Study.

    Science.gov (United States)

    West, Daniel W D; Abou Sawan, Sidney; Mazzulla, Michael; Williamson, Eric; Moore, Daniel R

    2017-07-11

    No study has concurrently measured changes in free-living whole body protein metabolism and exercise performance during recovery from an acute bout of resistance exercise. We aimed to determine if whey protein ingestion enhances whole body net protein balance and recovery of exercise performance during overnight (10 h) and 24 h recovery after whole body resistance exercise in trained men. In a double-blind crossover design, 12 trained men (76 ± 8 kg, 24 ± 4 years old, 14% ± 5% body fat; means ± standard deviation (SD)) performed resistance exercise in the evening prior to consuming either 25 g of whey protein (PRO; MuscleTech 100% Whey) or an energy-matched placebo (CHO) immediately post-exercise (0 h), and again the following morning (~10 h of recovery). A third randomized trial, completed by the same participants, involving no exercise and no supplement served as a rested control trial (Rest). Participants ingested [ 15 N]glycine to determine whole body protein kinetics and net protein balance over 10 and 24 h of recovery. Performance was assessed pre-exercise and at 0, 10, and 24 h of recovery using a battery of tests. Net protein balance tended to improve in PRO ( P = 0.064; effect size (ES) = 0.61, PRO vs. CHO) during overnight recovery. Over 24 h, net balance was enhanced in PRO ( P = 0.036) but not in CHO ( P = 0.84; ES = 0.69, PRO vs. CHO), which was mediated primarily by a reduction in protein breakdown (PRO protein supplementation improved MVC (ES = 0.76), REP (ES = 0.44), and peak power (ES = 0.55). In conclusion, whey protein supplementation enhances whole body anabolism, and may improve acute recovery of exercise performance after a strenuous bout of resistance exercise.

  18. Enhanced corrosion resistance and biocompatibility of β-type Ti–25Nb–25Zr alloy by electrochemical anodization

    International Nuclear Information System (INIS)

    Huang, Her-Hsiung; Wu, Chia-Ping; Sun, Ying-Sui; Huang, Hsun-Miao; Lee, Tzu-Hsin

    2013-01-01

    The biocompatibility of implants is largely determined by their surface characteristics. This study presents a novel method for performing electrochemical anodization on β-type Ti–25Nb–25Zr alloy with a low elastic modulus (approximately 70 GPa). This method results in a thin hybrid layer capable of enhancing the surface characteristics of the implants. We investigated the surface topography and microstructure of the resulting Ti–25Nb–25Zr alloy. The corrosion resistance was evaluated using potentiodynamic polarization curve measurements in simulated body fluid. The cytotoxicity was evaluated according to International Organization for Standardization 10993–5 specification. Cell adhesion of human bone marrow mesenchymal stem cells on the test specimens was observed using scanning electron microscopy and fluorescence microscopy. The anodization produced a thin (approximately 40 nm-thick) hybrid oxide layer with a nanoporous outer sublayer (pore size < 15 nm) and a dense inner layer. The thin hybrid oxide layer increased the corrosion resistance of the Ti–25Nb–25Zr alloy by increasing the corrosion potential and decreasing both the corrosion rate and passive current. Ti–25Nb–25Zr alloys with and without anodization treatment were non-toxic. Surface nanotopography on the anodized Ti–25Nb–25Zr alloy enhanced protein adsorption and cell adhesion. Our results demonstrate that electrochemical anodization increases the corrosion resistance and cell adhesion of β-type Ti–25Nb–25Zr alloy while providing a lower elastic modulus suitable for implant applications. - Highlights: • An electrochemical anodization was applied to β-type Ti–25Nb–25Zr alloy surface. • Anodized surface had nanoscale hybrid oxide layer. • Anodized surface increased corrosion resistance due to dense inner sublayer. • Anodized surface enhanced cell adhesion due to nanoporous outer sublayer. • Electrochemical anodization has potential as implant surface treatment

  19. Organic acids enhance bioavailability of tetracycline in water to Escherichia coli for uptake and expression of antibiotic resistance.

    Science.gov (United States)

    Zhang, Yingjie; Boyd, Stephen A; Teppen, Brian J; Tiedje, James M; Li, Hui

    2014-11-15

    Tetracyclines are a large class of antimicrobials used most extensively in livestock feeding operations. A large portion of tetracyclines administered to livestock is excreted in manure and urine which is collected in waste lagoons. Subsequent land application of these wastes introduces tetracyclines into the soil environment, where they could exert selective pressure for the development of antibiotic resistance genes in bacteria. Tetracyclines form metal-complexes in natural waters, which could reduce their bioavailability for bacterial uptake. We hypothesized that many naturally-occurring organic acids could effectively compete with tetracyclines as ligands for metal cations, hence altering the bioavailability of tetracyclines to bacteria in a manner that could enhance the selective pressure. In this study, we investigated the influence of acetic acid, succinic acid, malonic acid, oxalic acid and citric acid on tetracycline uptake from water by Escherichia coli bioreporter construct containing a tetracycline resistance gene which induces the emission of green fluorescence when activated. The presence of the added organic acid ligands altered tetracycline speciation in a manner that enhanced tetracycline uptake by E. coli. Increased bacterial uptake of tetracycline and concomitant enhanced antibiotic resistance response were quantified, and shown to be positively related to the degree of organic acid ligand complexation of metal cations in the order of citric acid > oxalic acid > malonic acid > succinic acid > acetic acid. The magnitude of the bioresponse increased with increasing aqueous organic acid concentration. Apparent positive relation between intracellular tetracycline concentration and zwitterionic tetracycline species in aqueous solution indicates that (net) neutral tetracycline is the species which most readily enters E. coli cells. Understanding how naturally-occurring organic acid ligands affect tetracycline speciation in solution, and how speciation

  20. Increase in Docetaxel-Resistance of Ovarian Carcinoma-Derived RMG-1 Cells with Enhanced Expression of Lewis Y Antigen

    Directory of Open Access Journals (Sweden)

    Bei Lin

    2011-10-01

    Full Text Available Epithelial carcinomas of the ovary exhibit the highest mortality rate among gynecologic malignancies. Studies found that the metabolism of glycolipids or carbohydrates is associated with acquirement of anticancer drug-resistance by cancer cells. This study was to characterize possible involvement of Lewis Y (LeY antigen in the drug-resistance of cancer cells. We transfected the α1,2-fucosyltransferase gene into human ovarian carcinoma-derived RMG-1 cells and established RMG-1-hFUT cells with enhanced expression of LeY. We determined the effects of docetaxel on the survival of cells by MTT assaying and observed the apoptosis of cells in the presence of docetaxel by flow cytometric analysis and by transmission electron microscopy. Plasma membranes and intracellular granules in RMG-1-hFUT cells were stained with anti-LeY antibody, the intensity of the staining was higher than that in control cells. The RMG-1-hFUT cells exhibited higher resistance to docetaxel than the control cells with regard to the docetaxel concentration and time course. After treatment with 10 μg/mL docetaxel for 72 h, the control cells, but not RMG-1-hFUT, contained abundant positively stained cell debris due to disintegration of the cytoskeleton. On transmission electron microscopy, although the control cells treated with docetaxel as above showed the following morphology, i.e., absence of villi, cells shrunken in size, pyknosis, agglutinated chromatin and cell buds containing nuclei in the process of apoptosis, the RMG-1-hFUT cells showed only agglutinated chromatin and vacuoles in the cytoplasm. In summary, cells with enhanced expression of LeY were shown to acquire docetaxel-resistance, indicating the possible involvement of glycoconjugates in the drug-resistance.

  1. Biological characterization of lead-enhanced exopolysaccharide produced by a lead resistant Enterobacter cloacae strain P2B.

    Science.gov (United States)

    Naik, Milind Mohan; Pandey, Anju; Dubey, Santosh Kumar

    2012-09-01

    A lead resistant bacterial strain isolated from effluent of lead battery manufacturing company of Goa, India has been identified as Enterobacter cloacae strain P2B based on morphological, biochemical characters, FAME profile and 16S rDNA sequence data. This bacterial strain could resist lead nitrate up to 1.6 mM. Significant increase in exopolysaccharide (EPS) production was observed as the production increased from 28 to 108 mg/L dry weight when exposed to 1.6 mM lead nitrate in Tris buffered minimal medium. Fourier-transformed infrared spectroscopy of this EPS revealed presence of several functional groups involved in metal binding viz. carboxyl, hydroxyl and amide groups along with glucuronic acid. Gas chromatography coupled with mass spectrometry analysis of alditol-acetate derivatives of acid hydrolysed EPS produced in presence of 1.6 mM lead nitrate demonstrated presence of several neutral sugars such as rhamnose, arabinose, xylose, mannose, galactose and glucose, which contribute to lead binding hydroxyl groups. Scanning electron microscope coupled with energy dispersive X-ray spectrometric analysis of this lead resistant strain exposed to 1.6 mM lead nitrate interestingly revealed mucous EPS surrounding bacterial cells which sequestered 17 % lead (as weight %) extracellularly and protected the bacterial cells from toxic effects of lead. This lead resistant strain also showed multidrug resistance. Thus these results significantly contribute to better understanding of structure, function and environmental application of lead-enhanced EPSs produced by bacteria. This lead-enhanced biopolymer can play a very important role in bioremediation of several heavy metals including lead.

  2. Coated steel rebar for enhanced concrete-steel bond strength and corrosion resistance.

    Science.gov (United States)

    2010-10-01

    This report summarizes the findings and recommendations on the use of enamel coating in reinforced concrete structures both for bond strength and : corrosion resistance of steel rebar. Extensive laboratory tests were conducted to characterize the pro...

  3. Enhancing corrosion resistance of reinforced concrete structures with hybrid fiber reinforced concrete

    International Nuclear Information System (INIS)

    Blunt, J.; Jen, G.; Ostertag, C.P.

    2015-01-01

    Highlights: • Reinforced concrete beams were subjected to cyclic flexural loading. • Hybrid fiber reinforced composites were effective in reducing corrosion rates. • Crack resistance due to fibers increased corrosion resistance of steel rebar. • Galvanic corrosion measurements underestimated corrosion rates. • Polarization resistance measurements predicted mass loss more accurately. - Abstract: Service loads well below the yield strength of steel reinforcing bars lead to cracking of reinforced concrete. This paper investigates whether the crack resistance of Hybrid Fiber Reinforced Concrete (HyFRC) reduces the corrosion rate of steel reinforcing bars in concrete after cyclic flexural loading. The reinforcing bars were extracted to examine their surface for corrosion and compare microcell and macrocell corrosion mass loss estimates against direct gravimetric measurements. A delay in corrosion initiation and lower active corrosion rates were observed in the HyFRC beam specimens when compared to reinforced specimens containing plain concrete matrices cycled at the same flexural load

  4. Enhanced oxidative killing of azole-resistant Candida glabrata strains with ERG11 deletion.

    Science.gov (United States)

    Kan, V L; Geber, A; Bennett, J E

    1996-01-01

    The susceptibility of genetically defined Candida glabrata strains to killing by H2O2 and neutrophils was assessed. Fluconazole-susceptible L5L and L5D strains demonstrated survival rates higher than those of two fluconazole-resistant strains lacking the ERG11 gene coding for 14 alpha-demethylase. Fluconazole resistance can occur by mechanisms which increase fungal susceptibility to oxidative killing by H2O2 and neutrophils. PMID:8807069

  5. Nordihydroguaiaretic acid enhances the activities of aminoglycosides against methicillin- sensitive and resistant Staphylococcus aureus in vitro and in vivo.

    Science.gov (United States)

    Cunningham-Oakes, Edward; Soren, Odel; Moussa, Caroline; Rathor, Getika; Liu, Yingjun; Coates, Anthony; Hu, Yanmin

    2015-01-01

    Infections caused by methicillin-sensitive Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) are prevalent. MRSA infections are difficult to treat and there are no new classes of antibiotics produced to the market to treat infections caused by the resistant bacteria. Therefore, using antibiotic enhancers to rescue existing classes of antibiotics is an attractive strategy. Nordihydroguaiaretic acid (NDGA) is an antioxidant compound found in extracts from plant Larrea Tridentata. It exhibits antimicrobial activity and may target bacterial cell membrane. Combination efficacies of NDGA with many classes of antibiotics were examined by chequerboard method against 200 clinical isolates of MRSA and MSSA. NDGA in combination with gentamicin, neomycin, and tobramycin was examined by time-kill assays. The synergistic combinations of NDGA and aminoglycosides were tested in vivo using a murine skin infection model. Calculations of the fractional inhibitory concentration index (FICI) showed that NDGA when combined with gentamicin, neomycin, or tobramycin displayed synergistic activities in more than 97% of MSSA and MRSA, respectively. Time kill analysis demonstrated that NDGA significantly augmented the activities of these aminoglycosides against MRSA and MSSA in vitro and in murine skin infection model. The enhanced activity of NDGA resides on its ability to damage bacterial cell membrane leading to accumulation of the antibiotics inside bacterial cells. We demonstrated that NDGA strongly revived the therapeutic potencies of aminoglycosides in vitro and in vivo. This combinational strategy could contribute major clinical implications to treat antibiotic resistant bacterial infections.

  6. Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males

    Directory of Open Access Journals (Sweden)

    Orem Ihsan

    2009-04-01

    Full Text Available Abstract Background Recent research has indicated that short term administration of glycine propionyl-L-carnitine (GPLC significantly elevates levels of nitric oxide metabolites at rest and in response to reactive hyperaemia. However, no scientific evidence exists that suggests such supplementation enhances exercise performance in healthy, trained individuals. The purpose of this study was to examine the effects of GPLC on the performance of repeated high intensity stationary cycle sprints with limited recovery periods in resistance trained male subjects. Methods In a double-blind, placebo-controlled, cross-over design, twenty-four male resistance trained subjects (25.2 ± 3.6 years participated in two test sessions separated by one week. Testing was performed 90 minutes following oral ingestion of either 4.5 grams GPLC or 4.5 grams cellulose (PL, in randomized order. The exercise testing protocol consisted of five 10-second Wingate cycle sprints separated by 1-minute active recovery periods. Peak (PP and mean values (MP of sprint power output and percent decrement of power (DEC were determined per bout and standardized relative to body masss. Heart rate (HR and blood lactate (LAC were measured prior to, during and following the five sprint bouts. Results Significant main effects (p Conclusion These findings indicate that short-term oral supplementation of GPLC can enhance peak power production in resistance trained males with significantly less LAC accumulation.

  7. Time dependent enhanced resistance against antibiotics & metal salts by planktonic & biofilm form of Acinetobacter haemolyticus MMC 8 clinical isolate

    Directory of Open Access Journals (Sweden)

    Sharvari Vijaykumar Gaidhani

    2014-01-01

    Full Text Available Background & objectives: Available literature shows paucity of reports describing antibiotic and metal resistance profile of biofilm forming clinical isolates of Acinetobacter haemolyticus. The present study was undertaken to evaluate the antibiotic and metal resistance profile of Indian clinical isolate of A. haemolyticus MMC 8 isolated from human pus sample in planktonic and biofilm form. Methods: Antibiotic susceptibility and minimum inhibitory concentration were determined employing broth and agar dilution techniques. Biofilm formation was evaluated quantitatively by microtiter plate method and variation in complex architecture was determined by scanning electron microscopy. Minimum biofilm inhibiting concentration was checked by Calgary biofilm device. Results: Planktonic A. haemolyticus MMC 8 was sensitive to 14 antibiotics, AgNO 3 and HgC1 2 resistant to streptomycin and intermediately resistant to netilmycin and kanamycin. MMC 8 exhibited temporal variation in amount and structure of biofilm. There was 32 - 4000 and 4 - 256 fold increase in antibiotic and metal salt concentration, respectively to inhibit biofilm over a period of 72 h as against susceptible planktonic counterparts. Total viable count in the range of 10 5 -10 6 cfu / ml was observed on plating minimum biofilm inhibiting concentration on Muller-Hinton Agar plate without antimicrobial agents. Biofilm forming cells were several folds more resistant to antibiotics and metal salts in comparison to planktonic cells. Presence of unaffected residual cell population indicated presence of persister cells. Interpretation & conclusions: The results indicate that biofilm formation causes enhanced resistance against antibiotics and metal salts in otherwise susceptible planktonic A. haemolyticus MMC 8.

  8. Resistance training enhances insulin suppression of endogenous glucose production in elderly women.

    Science.gov (United States)

    Honka, Miikka-Juhani; Bucci, Marco; Andersson, Jonathan; Huovinen, Ville; Guzzardi, Maria Angela; Sandboge, Samuel; Savisto, Nina; Salonen, Minna K; Badeau, Robert M; Parkkola, Riitta; Kullberg, Joel; Iozzo, Patricia; Eriksson, Johan G; Nuutila, Pirjo

    2016-03-15

    An altered prenatal environment during maternal obesity predisposes offspring to insulin resistance, obesity, and their consequent comorbidities, type 2 diabetes and cardiovascular disease. Telomere shortening and frailty are additional risk factors for these conditions. The aim of this study was to evaluate the effects of resistance training on hepatic metabolism and ectopic fat accumulation. Thirty-five frail elderly women, whose mothers' body mass index (BMI) was known, participated in a 4-mo resistance training program. Endogenous glucose production (EGP) and hepatic and visceral fat glucose uptake were measured during euglycemic hyperinsulinemia with [(18)F]fluorodeoxyglucose and positron emission tomography. Ectopic fat was measured using magnetic resonance spectroscopy and imaging. We found that the training intervention reduced EGP during insulin stimulation [from 5.4 (interquartile range 3.0, 7.0) to 3.9 (-0.4, 6.1) μmol·kg body wt(-1)·min(-1), P = 0.042] in the whole study group. Importantly, the reduction was higher among those whose EGP was more insulin resistant at baseline (higher than the median) [-5.6 (7.1) vs. 0.1 (5.4) μmol·kg body wt(-1)·min(-1), P = 0.015]. Furthermore, the decrease in EGP was associated with telomere elongation (r = -0.620, P = 0.001). The resistance training intervention did not change either hepatic or visceral fat glucose uptake or the amounts of ectopic fat. Maternal obesity did not influence the studied measures. In conclusion, resistance training improves suppression of EGP in elderly women. The finding of improved insulin sensitivity of EGP with associated telomere lengthening implies that elderly women can reduce their risk for type 2 diabetes and cardiovascular disease with resistance training. Copyright © 2016 the American Physiological Society.

  9. A compensatory mutation provides resistance to disparate HIV fusion inhibitor peptides and enhances membrane fusion.

    Directory of Open Access Journals (Sweden)

    Matthew P Wood

    Full Text Available Fusion inhibitors are a class of antiretroviral drugs used to prevent entry of HIV into host cells. Many of the fusion inhibitors being developed, including the drug enfuvirtide, are peptides designed to competitively inhibit the viral fusion protein gp41. With the emergence of drug resistance, there is an increased need for effective and unique alternatives within this class of antivirals. One such alternative is a class of cyclic, cationic, antimicrobial peptides known as θ-defensins, which are produced by many non-human primates and exhibit broad-spectrum antiviral and antibacterial activity. Currently, the θ-defensin analog RC-101 is being developed as a microbicide due to its specific antiviral activity, lack of toxicity to cells and tissues, and safety in animals. Understanding potential RC-101 resistance, and how resistance to other fusion inhibitors affects RC-101 susceptibility, is critical for future development. In previous studies, we identified a mutant, R5-tropic virus that had evolved partial resistance to RC-101 during in vitro selection. Here, we report that a secondary mutation in gp41 was found to restore replicative fitness, membrane fusion, and the rate of viral entry, which were compromised by an initial mutation providing partial RC-101 resistance. Interestingly, we show that RC-101 is effective against two enfuvirtide-resistant mutants, demonstrating the clinical importance of RC-101 as a unique fusion inhibitor. These findings both expand our understanding of HIV drug-resistance to diverse peptide fusion inhibitors and emphasize the significance of compensatory gp41 mutations.

  10. Insulin resistance enhances the mitogen-activated protein kinase signaling pathway in ovarian granulosa cells.

    Directory of Open Access Journals (Sweden)

    Linghui Kong

    Full Text Available The ovary is the main regulator of female fertility. Granulosa cell dysfunction may be involved in various reproductive endocrine disorders. Here we investigated the effect of insulin resistance on the metabolism and function of ovarian granulosa cells, and dissected the functional status of the mitogen-activated protein kinase signaling pathway in these cells. Our data showed that dexamethasone-induced insulin resistance in mouse granulosa cells reduced insulin sensitivity, accompanied with an increase in phosphorylation of p44/42 mitogen-activated protein kinase. Furthermore, up-regulation of cytochrome P450 subfamily 17 and testosterone and down-regulation of progesterone were observed in insulin-resistant mouse granulosa cells. Inhibition of p44/42 mitogen-activated protein kinase after induction of insulin resistance in mouse granulosa cells decreased phosphorylation of p44/42 mitogen-activated protein kinase, downregulated cytochrome P450 subfamily 17 and lowered progesterone production. This insulin resistance cell model can successfully demonstrate certain mechanisms such as hyperandrogenism, which may inspire a new strategy for treating reproductive endocrine disorders by regulating cell signaling pathways.

  11. Enhanced switching stability in Ta2O5 resistive RAM by fluorine doping

    Science.gov (United States)

    Sedghi, N.; Li, H.; Brunell, I. F.; Dawson, K.; Guo, Y.; Potter, R. J.; Gibbon, J. T.; Dhanak, V. R.; Zhang, W. D.; Zhang, J. F.; Hall, S.; Robertson, J.; Chalker, P. R.

    2017-08-01

    The effect of fluorine doping on the switching stability of Ta2O5 resistive random access memory devices is investigated. It shows that the dopant serves to increase the memory window and improve the stability of the resistive states due to the neutralization of oxygen vacancies. The ability to alter the current in the low resistance state with set current compliance coupled with large memory window makes multilevel cell switching more favorable. The devices have set and reset voltages of <1 V with improved stability due to the fluorine doping. Density functional modeling shows that the incorporation of fluorine dopant atoms at the two-fold O vacancy site in the oxide network removes the defect state in the mid bandgap, lowering the overall density of defects capable of forming conductive filaments. This reduces the probability of forming alternative conducting paths and hence improves the current stability in the low resistance states. The doped devices exhibit more stable resistive states in both dc and pulsed set and reset cycles. The retention failure time is estimated to be a minimum of 2 years for F-doped devices measured by temperature accelerated and stress voltage accelerated retention failure methods.

  12. GmPGIP3 enhanced resistance to both take-all and common root rot diseases in transgenic wheat.

    Science.gov (United States)

    Wang, Aiyun; Wei, Xuening; Rong, Wei; Dang, Liang; Du, Li-Pu; Qi, Lin; Xu, Hui-Jun; Shao, Yanjun; Zhang, Zengyan

    2015-05-01

    Take-all (caused by the fungal pathogen Gaeumannomyces graminis var. tritici, Ggt) and common root rot (caused by Bipolaris sorokiniana) are devastating root diseases of wheat (Triticum aestivum L.). Development of resistant wheat cultivars has been a challenge since no resistant wheat accession is available. GmPGIP3, one member of polygalacturonase-inhibiting protein (PGIP) family in soybean (Glycine max), exhibited inhibition activity against fungal endopolygalacturonases (PGs) in vitro. In this study, the GmPGIP3 transgenic wheat plants were generated and used to assess the effectiveness of GmPGIP3 in protecting wheat from the infection of Ggt and B. sorokiniana. Four independent transgenic lines were identified by genomic PCR, Southern blot, and reverse transcription PCR (RT-PCR). The introduced GmPGIP3 was integrated into the genomes of these transgenic lines and could be expressed. The expressing GmPGIP3 protein in these transgenic wheat lines could inhibit the PGs produced by Ggt and B. sorokiniana. The disease response assessments postinoculation showed that the GmPGIP3-expressing transgenic wheat lines displayed significantly enhanced resistance to both take-all and common root rot diseases caused by the infection of Ggt and B. sorokiniana. These data suggested that GmPGIP3 is an attractive gene resource in improving resistance to both take-all and common root rot diseases in wheat.

  13. Enhanced Oxidation-Resistant Cu@Ni Core-Shell Nanoparticles for Printed Flexible Electrodes.

    Science.gov (United States)

    Kim, Tae Gon; Park, Hye Jin; Woo, Kyoohee; Jeong, Sunho; Choi, Youngmin; Lee, Su Yeon

    2018-01-10

    In this work, the fabrication and application of highly conductive, robust, flexible, and oxidation-resistant Cu-Ni core-shell nanoparticle (NP)-based electrodes have been reported. Cu@Ni core-shell NPs with a tunable Ni shell thickness were synthesized by varying the Cu/Ni molar ratios in the precursor solution. Through continuous spray coating and flash photonic sintering without an inert atmosphere, large-area Cu@Ni NP-based conductors were fabricated on various polymer substrates. These NP-based electrodes demonstrate a low sheet resistance of 1.3 Ω sq -1 under an optical energy dose of 1.5 J cm -2 . In addition, they exhibit highly stable sheet resistances (ΔR/R 0 flexible heater fabricated from the Cu@Ni film is demonstrated, which shows uniform heat distribution and stable temperature compared to those of a pure Cu film.

  14. Development of hyper osmotic resistant CHO host cells for enhanced antibody production.

    Science.gov (United States)

    Kamachi, Yasuharu; Omasa, Takeshi

    2018-04-01

    Cell culture platform processes are generally employed to shorten the duration of new product development. A fed-batch process with continuous feeding is a conventional platform process for monoclonal antibody production using Chinese hamster ovary (CHO) cells. To establish a simplified platform process, the feeding method can be changed from continuous feed to bolus feed. However, this change induces a rapid increase of osmolality by the bolus addition of nutrients. The increased osmolality suppresses cell culture growth, and the final product concentration is decreased. In this study, osmotic resistant CHO host cells were developed to attain a high product concentration. To establish hyper osmotic resistant CHO host cells, CHO-S host cells were passaged long-term in a hyper osmotic basal medium. There were marked differences in cell growth of the original and established host cells under iso- (328 mOsm/kg) or hyper-osmolality (over 450 mOsm/kg) conditions. Cell growth of the original CHO host cells was markedly decreased by the induction of osmotic stress, whereas cell growth of the hyper osmotic resistant CHO host cells was not affected. The maximum viable cell concentration of hyper osmotic resistant CHO host cells was 132% of CHO-S host cells after the induction of osmotic stress. Moreover, the hyper osmotic resistant characteristic of established CHO host cells was maintained even after seven passages in iso-osmolality basal medium. The use of hyper osmotic resistance CHO host cells to create a monoclonal antibody production cell line might be a new approach to increase final antibody concentrations with a fed-batch process. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  15. Cow excrements enhance the occurrence of tetracycline resistance genes in soil regardless of their oxytetracycline content

    Czech Academy of Sciences Publication Activity Database

    Kyselková, Martina; Jirout, Jiří; Chroňáková, Alica; Vrchotová, Naděžda; Bradley, R.; Schmitt, H.; Elhottová, Dana

    2013-01-01

    Roč. 93, č. 10 (2013), s. 2413-2418 ISSN 0045-6535 R&D Projects: GA ČR GAP504/10/2077; GA MŠk(CZ) EE2.3.30.0032; GA MŠk(CZ) ED1.1.00/02.0073 Grant - others:OECD(FR) JA00054767 Institutional support: RVO:60077344 ; RVO:67179843 Keywords : cattle excrement * environmental risk assessment * manured soil * oxytetracycline * tetracycline resistance * tetracycline resistance gene Subject RIV: EE - Microbiology, Virology Impact factor: 3.499, year: 2013

  16. Extracellular matrix metalloproteinase inducer enhances host resistance against pseudomonas aeruginosa infection through MAPK signaling pathway

    OpenAIRE

    Li, Yongwei; Chen, Lu; Wang, Chunxia; Chen, Jianshe; Zhang, Xiaoqian; Hu, Yue; Niu, Xiaobin; Pei, Dongxu; He, Zhiqiang; Bi, Yongyi

    2016-01-01

    This study aims to explore the role of extra-cellular matrix metalloproteinase inducer (EMMPRIN) in the drug resistance of the pseudomonas aeruginosa (PA). The BALB/c mice were transfected with PA, then the mice were infected with the siRNA of EMMPRIN to silence the EMMPRIN gene. The EMMPRIN mRNA and protein were detected by using RT-PCR and western blot, respectively. In order to examine the function of EMMPRIN in drug resistance of PA, the BALB/c and C57BL/6 mice were treated with EMMPRIN s...

  17. Whey Protein Supplementation Enhances Whole Body Protein Metabolism and Performance Recovery after Resistance Exercise: A Double-Blind Crossover Study

    Directory of Open Access Journals (Sweden)

    Daniel W. D. West

    2017-07-01

    Full Text Available No study has concurrently measured changes in free-living whole body protein metabolism and exercise performance during recovery from an acute bout of resistance exercise. We aimed to determine if whey protein ingestion enhances whole body net protein balance and recovery of exercise performance during overnight (10 h and 24 h recovery after whole body resistance exercise in trained men. In a double-blind crossover design, 12 trained men (76 ± 8 kg, 24 ± 4 years old, 14% ± 5% body fat; means ± standard deviation (SD performed resistance exercise in the evening prior to consuming either 25 g of whey protein (PRO; MuscleTech 100% Whey or an energy-matched placebo (CHO immediately post-exercise (0 h, and again the following morning (~10 h of recovery. A third randomized trial, completed by the same participants, involving no exercise and no supplement served as a rested control trial (Rest. Participants ingested [15N]glycine to determine whole body protein kinetics and net protein balance over 10 and 24 h of recovery. Performance was assessed pre-exercise and at 0, 10, and 24 h of recovery using a battery of tests. Net protein balance tended to improve in PRO (P = 0.064; effect size (ES = 0.61, PRO vs. CHO during overnight recovery. Over 24 h, net balance was enhanced in PRO (P = 0.036 but not in CHO (P = 0.84; ES = 0.69, PRO vs. CHO, which was mediated primarily by a reduction in protein breakdown (PRO < CHO; P < 0.01. Exercise decreased repetitions to failure (REP, maximal strength (MVC, peak and mean power, and countermovement jump performance (CMJ at 0 h (all P < 0.05 vs. Pre. At 10 h, there were small-to-moderate effects for enhanced recovery of the MVC (ES = 0.56, mean power (ES = 0.49, and CMJ variables (ES: 0.27–0.49 in PRO. At 24 h, protein supplementation improved MVC (ES = 0.76, REP (ES = 0.44, and peak power (ES = 0.55. In conclusion, whey protein supplementation enhances whole body anabolism, and may improve acute recovery of

  18. Multielement (P-Yb-Zr-Ce-Al-Ca) fiber for moderate-power laser application with enhanced photodarkening resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Dhar, Anirban; Paul, Mukul Chandra [CSIR-Central Glass and Ceramic Research Institute, 196 Raja S. C. Mullick Road, Jadavpur, Kolkata 700 032 (India); Das, Shyamal; Reddy, Pinninty Harshavardhan; Siddiki, Salim H.; Dutta, Debjit; Pal, Mrinmay [Academy of Scientific and Innovative Research (AcSIR), CSIR-CGCRI Campus, Kolkata 700 032 (India); Kir' yanov, Alexander V. [Centro de Investigaciones en Optica, Loma del Bosque 115, Col. Lomas del Campestre, Leon 37150, Guanajuato (Mexico)

    2017-06-15

    Multielement (ME) (P-Yb-Zr-Ce-Al-Ca) nanophase separated silica-glass-based optical fiber is fabricated through a conventional-modified chemical vapor deposition (MCVD) process, coupled with solution doping technique. The lasing and photodarkening behaviors of this ME fiber have been demonstrated and compared, in terms of its photodarkening (PD) performance at moderate pump powers (tens of Watts), with standard Yb-doped fiber with phospho-alumino-silicate (PAS) glass composition, which clearly reveals that the ME-Yb doped fiber is a promising candidate for laser applications with enhanced PD resistivity. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Overexpression of a modified plant thionin enhances disease resistance to citrus canker and Huanglongbing (HLB)

    Science.gov (United States)

    Huanglongbing (HLB or citrus greening disease) caused by Candidatus Liberibacter asiaticus (Las) is a great threat to the United States citrus industry. There are no proven strategies to eliminate HLB disease and no cultivar has been identified with strong HLB resistance. Citrus canker is also an ec...

  20. SP-LL-37, human antimicrobial peptide, enhances disease resistance in transgenic rice.

    Science.gov (United States)

    Lee, In Hye; Jung, Yu-Jin; Cho, Yong Gu; Nou, Ill Sup; Huq, Md Amdadul; Nogoy, Franz Marielle; Kang, Kwon-Kyoo

    2017-01-01

    Human LL-37 is a multifunctional antimicrobial peptide of cathelicidin family. It has been shown in recent studies that it can serve as a host's defense against influenza A virus. We now demonstrate in this study how signal peptide LL-37 (SP-LL-37) can be used in rice resistance against bacterial leaf blight and blast. We synthesized LL-37 peptide and subcloned in a recombinant pPZP vector with pGD1 as promoter. SP-LL-37 was introduced into rice plants by Agrobacterium mediated transformation. Stable expression of SP-LL-37 in transgenic rice plants was confirmed by RT-PCR and ELISA analyses. Subcellular localization of SP-LL-37-GFP fusion protein showed evidently in intercellular space. Our data on testing for resistance to bacterial leaf blight and blast revealed that the transgenic lines are highly resistant compared to its wildtype. Our results suggest that LL-37 can be further explored to improve wide-spectrum resistance to biotic stress in rice.

  1. Medical-grade honey enriched with antimicrobial peptides has enhanced activity against antibiotic-resistant pathogens

    NARCIS (Netherlands)

    Kwakman, P.H.S.; Boer, den L.; Ruyter-Spira, C.; Creemers-Molenaar, T.; Helsper, J.P.F.G.; Vandenbroucke-Grauls, C.M.J.E.; Zaat, S.A.J.; Velde, te A.A.

    2011-01-01

    Honey has potent activity against both antibioticsensitive and -resistant bacteria, and is an interesting agent for topical antimicrobial application to wounds. As honey is diluted by wound exudate, rapid bactericidal activity up to high dilution is a prerequisite for its successful application. We

  2. Medical-grade honey enriched with antimicrobial peptides has enhanced activity against antibiotic-resistant pathogens

    NARCIS (Netherlands)

    Kwakman, P. H. S.; de Boer, L.; Ruyter-Spira, C. P.; Creemers-Molenaar, T.; Helsper, J. P. F. G.; Vandenbroucke-Grauls, C. M. J. E.; Zaat, S. A. J.; te Velde, A. A.

    2011-01-01

    Honey has potent activity against both antibiotic-sensitive and -resistant bacteria, and is an interesting agent for topical antimicrobial application to wounds. As honey is diluted by wound exudate, rapid bactericidal activity up to high dilution is a prerequisite for its successful application. We

  3. Enhancement of resistance to coccidiosis and necrotic enteritis in broiler chickens by dietary muscadine pomace.

    Science.gov (United States)

    McDougald, L R; Hofacre, C; Mathis, G; Fuller, L; Hargrove, J L; Greenspan, P; Hartle, D K

    2008-12-01

    Muscadine pomace (MP), a by-product of the production of wine and juice from Vitis rotundifolia, was dried and tested in chickens for effects on primary resistance to coccidiosis, development of protective immunity after vaccination with live coccidia, and resistance to necrotic enteritis (NE) caused by the joint action of Clostridium perfringens and coccidia. To test primary resistance to coccidiosis, 2-wk-old chicks were given 2% or 5% MP in the diet and inoculated with Eimeria acervulina and E. maxima. Birds given MP at either level had significantly (P chickens were given 2% or 5% MP and grown to 42 days to test the palatability of MP. Birds given 2% MP in feed grew similarly to untreated controls, but birds given 5% had poorer average live weight. This suggested a negative effect on feed intake at the higher level. The effects of dietary 0.5% or 2.0% MP on immune protection were tested after live coccidiosis vaccination in the hatchery. Chicks were removed from each pen at 21 days of age and challenged with E acervulina, E. maxima, and E. tenella. Resistance to infection was improved by MP as suggested by significantly (P chickens. Chicks were inoculated with live coccidia at 14 days of age and dosed orally with live cultures of C perfringens on day 19, day 20, and day 21. Enteritis caused 48% mortality in the first study and 67% mortality in the second study. Dietary MP at 0.5-2.0% significantly (P chickens.

  4. A CRISPR-Cas system enhances envelope integrity mediating antibiotic resistance and inflammasome evasion

    NARCIS (Netherlands)

    T.R. Sampson (Timothy); B.A. Napier (Brooke); M.R. Schroeder (Max); J. Zhao (Jingshi); R.P.L. Louwen (Rogier); C.-Y. Chin (Chui-Yoke); H.K. Ratner (Hannah); A.C. Llewellyn (Anna); C.L. Jones (Crystal); H. Laroui (Hamed); D. Merlin (Didier); P. Zhou (Pei); H.P. Endtz (Hubert); D.S. Weiss (David)

    2014-01-01

    textabstractClustered, regularly interspaced, short palindromic repeats-CRISPR associated (CRISPR-Cas) systems defend bacteria against foreign nucleic acids, such as during bacteriophage infection and transformation, processes which cause envelope stress. It is unclear if these machineries enhance

  5. Changes of renal blood flow after ESWL: assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index.

    Science.gov (United States)

    Abd Ellah, Mohamed; Kremser, Christian; Pallwein, Leo; Aigner, Friedrich; Schocke, Michael; Peschel, Reinhard; Pedross, Florian; Pinggera, Germar-Michael; Wolf, Christian; Alsharkawy, Mostafa A M; Jaschke, Werner; Frauscher, Ferdinand

    2010-10-01

    The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12h before and 12h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (pESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.

  6. Root bacterial endophytes confer drought resistance and enhance expression and activity of a vacuolar H+ -pumping pyrophosphatase in pepper plants.

    Science.gov (United States)

    Vigani, Gianpiero; Rolli, Eleonora; Marasco, Ramona; Dell'Orto, Marta; Michoud, Grégoire; Soussi, Asma; Raddadi, Noura; Borin, Sara; Sorlini, Claudia; Zocchi, Graziano; Daffonchio, Daniele

    2018-05-22

    It has been previously shown that the transgenic overexpression of the plant root vacuolar proton pumps H + -ATPase (V-ATPase) and H + -PPase (V-PPase) confer tolerance to drought. Since plant-root endophytic bacteria can also promote drought tolerance, we hypothesize that such promotion can be associated to the enhancement of the host vacuolar proton pumps expression and activity. To test this hypothesis, we selected two endophytic bacteria endowed with an array of in vitro plant growth promoting traits. Their genome sequences confirmed the presence of traits previously shown to confer drought resistance to plants, such as the synthesis of nitric oxide and of organic volatile organic compounds. We used the two strains on pepper (Capsicuum annuum L.) because of its high sensitivity to drought. Under drought conditions, both strains stimulated a larger root system and enhanced the leaves' photosynthetic activity. By testing the expression and activity of the vacuolar proton pumps, H + -ATPase (V-ATPase) and H + -PPase (V-PPase), we found that bacterial colonization enhanced V-PPase only. We conclude that the enhanced expression and activity of V-PPase can be favoured by the colonization of drought-tolerance-inducing bacterial endophytes. This article is protected by copyright. All rights reserved. © 2018 Society for Applied Microbiology and John Wiley & Sons Ltd.

  7. Denaturing of plutonium by transmutation of minor-actinides for enhancement of proliferation resistance

    International Nuclear Information System (INIS)

    Sagara, Hiroshi; Saito, Masaki; Peryoga, Yoga; Ezoubtchenko, Alexey; Takivayev, Alan

    2005-01-01

    Feasibility study for the plutonium denaturing by utilizing minor-actinide transmutation in light water reactors has been performed. And the intrinsic feature of proliferation resistance of plutonium has been discussed based on IAEA's publication and Kessler's proposal. The analytical results show that not only 238 Pu but also other plutonium isotopes with even-mass-number have very important role for denaturing of plutonium due to their relatively large critical mass and noticeably high spontaneous fission neutron generation. With the change of the minor-actinide doping ratio in U-Pu mix oxide fuel and moderator to fuel ratio, it is found that the reactor-grade plutonium from conventional light water reactors can be denatured to satisfy the proliferation resistance criterion based on the Kessler's proposal but not to be sufficient for the criterion based on IAEA's publication. It has been also confirmed that all the safety coefficients take negative value throughout the irradiation. (author)

  8. Enhancement of oxidation resistance in Cu and Cu(Al) thin layers

    Energy Technology Data Exchange (ETDEWEB)

    Horvath, Z.E.; Peto, G. E-mail: peto@mfa.kfki.hu; Paszti, Z.; Zsoldos, E.; Szilagyi, E.; Battistig, G.; Lohner, T.; Molnar, G.L.; Gyulai, J

    1999-01-02

    High conductivity and good resistance to electromigration makes copper a promising interconnect material in microelectronics. However, one of its disadvantages is the poor corrosion resistance. Two methods of passivation are investigated and compared: Al alloying and BF{sub 2}{sup +} ion implantation. X-ray diffraction (XRD) and Rutherford Backscattering Spectrometry (RBS) show the oxidation inhibition of both methods, but the different ratio of CuO{sub 2} to CuO phases suggests different mechanisms of passivation. There are no definite oxide lines in the XRD spectrum of the implanted and annealed Cu(Al) sample, so the presence of Al and the implantation together give increased protection against oxidation. The difference between the two mechanisms of oxidation inhibition is discussed briefly.

  9. Enhancement of oxidation resistance in Cu and Cu(Al) thin layers

    International Nuclear Information System (INIS)

    Horvath, Z.E.; Peto, G.; Paszti, Z.; Zsoldos, E.; Szilagyi, E.; Battistig, G.; Lohner, T.; Molnar, G.L.; Gyulai, J.

    1999-01-01

    High conductivity and good resistance to electromigration makes copper a promising interconnect material in microelectronics. However, one of its disadvantages is the poor corrosion resistance. Two methods of passivation are investigated and compared: Al alloying and BF 2 + ion implantation. X-ray diffraction (XRD) and Rutherford Backscattering Spectrometry (RBS) show the oxidation inhibition of both methods, but the different ratio of CuO 2 to CuO phases suggests different mechanisms of passivation. There are no definite oxide lines in the XRD spectrum of the implanted and annealed Cu(Al) sample, so the presence of Al and the implantation together give increased protection against oxidation. The difference between the two mechanisms of oxidation inhibition is discussed briefly

  10. Thermally oxidized titania nanotubes enhance the corrosion resistance of Ti6Al4V.

    Science.gov (United States)

    Grotberg, John; Hamlekhan, Azhang; Butt, Arman; Patel, Sweetu; Royhman, Dmitry; Shokuhfar, Tolou; Sukotjo, Cortino; Takoudis, Christos; Mathew, Mathew T

    2016-02-01

    The negative impact of in vivo corrosion of metallic biomedical implants remains a complex problem in the medical field. We aimed to determine the effects of electrochemical anodization (60V, 2h) and thermal oxidation (600°C) on the corrosive behavior of Ti-6Al-4V, with serum proteins, at physiological temperature. Anodization produced a mixture of anatase and amorphous TiO2 nanopores and nanotubes, while the annealing process yielded an anatase/rutile mixture of TiO2 nanopores and nanotubes. The surface area was analyzed by the Brunauer-Emmett-Teller method and was estimated to be 3 orders of magnitude higher than that of polished control samples. Corrosion resistance was evaluated on the parameters of open circuit potential, corrosion potential, corrosion current density, passivation current density, polarization resistance and equivalent circuit modeling. Samples both anodized and thermally oxidized exhibited shifts of open circuit potential and corrosion potential in the noble direction, indicating a more stable nanoporous/nanotube layer, as well as lower corrosion current densities and passivation current densities than the smooth control. They also showed increased polarization resistance and diffusion limited charge transfer within the bulk oxide layer. The treatment groups studied can be ordered from greatest corrosion resistance to least as Anodized+Thermally Oxidized > Anodized > Smooth > Thermally Oxidized for the conditions investigated. This study concludes that anodized surface has a potential to prevent long term implant failure due to corrosion in a complex in-vivo environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Bioactive glass–ceramic coating for enhancing the in vitro corrosion resistance of biodegradable Mg alloy

    International Nuclear Information System (INIS)

    Ye Xinyu; Cai Shu; Dou Ying; Xu Guohua; Huang Kai; Ren Mengguo; Wang Xuexin

    2012-01-01

    Highlights: ► Sol–gel derived 45S5 glass–ceramic coating was prepared on Mg alloy substrate. ► The corrosion resistance of glass–ceramic coated Mg alloy was markedly improved. ► The corrosion behavior of the coated sample varied due to the cracking of coating. - Abstract: In this work, a bioactive 45S5 glass–ceramic coating was synthesized on magnesium (Mg) alloy substrate by using a sol–gel dip-coating method, to improve the initial corrosion resistance of AZ31 Mg alloy. The surface morphology and phase composition of the glass–ceramic coating were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The coating composed of amorphous phase and crystalline phase Na 2 Ca 2 Si 3 O 9 , with the thickness of ∼1.0 μm, exhibited a uniform and crack-free surface morphology. The corrosion behavior of the uncoated and coated Mg alloy substrates was investigated by the electrochemical measurements and immersion tests in simulated body fluid (SBF). Potentiodynamic polarization tests recorded an increase of potential (E corr ) form −1.60 V to −1.48 V, and a reduction of corrosion current density (i corr ) from 4.48 μA cm −2 to 0.16 μA cm −2 , due to the protection provided by the glass–ceramic coating. Immersion tests also showed the markedly improved corrosion resistance of the coated sample over the immersion period of 7 days. Moreover, after 14 days of immersion in SBF, the corrosion resistance of the coated sample declined due to the cracking of the glass–ceramic coating, which was confirmed by electrochemical impedance spectroscopy (EIS) analysis. The results suggested that the 45S5 glass–ceramic coated Mg alloy could provide a suitable corrosion behavior for use as degradable implants.

  12. The enhancement in wear resistance of W18Cr4V steel by ion implantation

    International Nuclear Information System (INIS)

    Zhou Ping; Xu Peiguang

    1987-01-01

    Two new methods of ion implantation were adopted in comparison with nitrogen implantation: carbon monoxide was implanted directly into W18Cr4V steel, and nitrogen was implanted into a deposited titanium film about 1000 A thick. It is shown that higher surface hardness and wear resistance have been achieved. The composition and phase structure of the implanted layer was determined in detail. The wear mechanisms were discussed

  13. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    DEFF Research Database (Denmark)

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham

    2016-01-01

    be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing...... findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT....

  14. Ester-free Thiol-X Resins: New Materials with Enhanced Mechanical Behavior and Solvent Resistance

    OpenAIRE

    Podgórski, Maciej; Becka, Eftalda; Chatani, Shunsuke; Claudino, Mauro; Bowman, Christopher N.

    2015-01-01

    A series of thiol-Michael and radical thiol-ene network polymers were successfully prepared from ester-free as well as ester-containing monomer formulations. Polymerization reaction rates, dynamic mechanical analysis, and solvent resistance experiments were performed and compared between compositions with varied ester loading. The incorporation of ester-free alkyl thiol, vinyl sulfone and allylic monomers significantly improved the mechanical properties when compared with commercial, mercapto...

  15. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    International Nuclear Information System (INIS)

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham; Sarri, Gianluca; Ng, Chi-Ho; Sharba, Ahmed; Man, Hau-Chung

    2016-01-01

    Graphical abstract: - Highlights: • Laser technology is a fast, clean and flexible method for surface hardening of TNZT. • Laser can form a protective hard layer on TNZT surface without altering surface roughness. • The laser-formed layer is metallurgically bonded to the substrate. • Laser-treated TNZT is highly resistant to corrosion and wear in Hank's solution. - Abstract: The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti–Nb–Zr–Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti–35.3Nb–7.3Zr–5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing incidence X-ray diffraction (GI-XRD) and X-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks’ solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT.

  16. Enhanced expression of transferrin receptor confers UV-resistance in human and monkey cells

    International Nuclear Information System (INIS)

    Chen, Zheng; Nomura, Jun; Suzuki, Toshikazu; Suzuki, Nobuo

    2005-01-01

    One of the most intriguing biological subjects is cell-surface molecules that regulate the susceptibility of human cells to cell-killing effects after irradiation with far-ultraviolet light (UV, principally 254 nm wavelength). Human RSa cells have unusual sensitivity to UV-induced cell-killing. We searched for molecules on the cell-surface of RSa cells that were present in different amounts as compared to a variant of these cells, UV r -1 cells, which have increased resistance to UV cell-killing. Among the 21 molecules examined, the amount of transferrin receptor (TfR) protein was found to be 2-fold higher in UV r -1 cells compared with in RSa cells. The amounts of this protein were also higher in the UV-resistant hematopoietic cell lines, CEM6 and Daudi, as compared to the UV-sensitive cell lines, Molt4 and 697. Culturing of UV r -1 cells in a medium containing anti-transferrin antibodies resulted in sensitization of the cells to UV cell-killing as demonstrated by colony formation assay. Similar results were observed by treatment of the cells with TfR siRNA. In contrast, overexpression of TfR protein led to a resistance to UV cell-killing in RSa cells and monkey COS7 cells as demonstrated by both colony formation and apoptosis assay. In TfR-overexpressing cells, reduction of p53 and Bax protein was observed after UV-irradiation. Thus, TfR expression appears to be involved in the regulation of UV-resistance, possibly via modulation of the amount of p53 and Bax protein. (author)

  17. Magnetic field induced enhancement of resistance in polycrystalline ZrTe5

    Science.gov (United States)

    Behera, Prakash; Bera, Sumit; Patidar, Manju Mishra; Singh, Durgesh; Mishra, A. K.; Krishnan, M.; Gangrade, M.; Deshpande, U. P.; Venkatesh, R.; Ganesan, V.

    2018-04-01

    Transport properties of the polycrystalline ZrTe5 showing a considerable positive Magneto-Resistance (MR) in the intermediate temperatures has been reported. Substantial shift of peak temperature by approximately 65 K with an applied magnetic field of 13.5 Tesla has been observed. Magneto resistance of this polycrystalline sample (˜100%) is comparable with its single crystalline counterpart reported in literature. The peak intensity scales with peak temperature and obeys reasonably the Dionne relationship that is a clear indication of polaron mediated conduction in this system. Magneto Resistance (MR) in this system is attributed to the two carrier polaronic conduction model similar to the Holstein's approach. The results are further complemented with the Peak shift in magnetic field expected for a system having a fraction of localized carrier density. This observation places this famous thermoelectric material that displays a topological Dirac to Weyl transition in magnetic field in to the family of materials that have potential technological applications in the liquid nitrogen temperature range viz. 85-150 K.

  18. Evolution of copper arsenate resistance for enhanced enargite bioleaching using the extreme thermoacidophile Metallosphaera sedula.

    Science.gov (United States)

    Ai, Chenbing; McCarthy, Samuel; Liang, Yuting; Rudrappa, Deepak; Qiu, Guanzhou; Blum, Paul

    2017-12-01

    Adaptive laboratory evolution (ALE) was employed to isolate arsenate and copper cross-resistant strains, from the copper-resistant M. sedula CuR1. The evolved strains, M. sedula ARS50-1 and M. sedula ARS50-2, contained 12 and 13 additional mutations, respectively, relative to M. sedula CuR1. Bioleaching capacity of a defined consortium (consisting of a naturally occurring strain and a genetically engineered copper sensitive strain) was increased by introduction of M. sedula ARS50-2, with 5.31 and 26.29% more copper recovered from enargite at a pulp density (PD) of 1 and 3% (w/v), respectively. M. sedula ARS50-2 arose as the predominant species and modulated the proportions of the other two strains after it had been introduced. Collectively, the higher Cu 2+ resistance trait of M. sedula ARS50-2 resulted in a modulated microbial community structure, and consolidating enargite bioleaching especially at elevated PD.

  19. Enhancement of wear and corrosion resistance of beta titanium alloy by laser gas alloying with nitrogen

    Science.gov (United States)

    Chan, Chi-Wai; Lee, Seunghwan; Smith, Graham; Sarri, Gianluca; Ng, Chi-Ho; Sharba, Ahmed; Man, Hau-Chung

    2016-03-01

    The relatively high elastic modulus coupled with the presence of toxic vanadium (V) in Ti6Al4V alloy has long been a concern in orthopaedic applications. To solve the problem, a variety of non-toxic and low modulus beta-titanium (beta-Ti) alloys have been developed. Among the beta-Ti alloy family, the quaternary Ti-Nb-Zr-Ta (TNZT) alloys have received the highest attention as a promising replacement for Ti6Al4V due to their lower elastic modulus and outstanding long term stability against corrosion in biological environments. However, the inferior wear resistance of TNZT is still a problem that must be resolved before commercialising in the orthopaedic market. In this work, a newly developed laser surface treatment technique was employed to improve the surface properties of Ti-35.3Nb-7.3Zr-5.7Ta alloy. The surface structure and composition of the laser-treated TNZT surface were examined by grazing incidence X-ray diffraction (GI-XRD) and X-ray photoelectron spectroscopy (XPS). The wear and corrosion resistance were evaluated by pin-on-plate sliding test and anodic polarisation test in Hanks' solution. The experimental results were compared with the untreated (or base) TNZT material. The research findings showed that the laser surface treatment technique reported in this work can effectively improve the wear and corrosion resistance of TNZT.

  20. Non-cytotoxic nanomaterials enhance antimicrobial activities of cefmetazole against multidrug-resistant Neisseria gonorrhoeae.

    Directory of Open Access Journals (Sweden)

    Lan-Hui Li

    Full Text Available The emergence and spread of antibiotic-resistant Neisseria gonorrhoeae has led to difficulties in treating patients, and novel strategies to prevent and treat this infection are urgently needed. Here, we examined 21 different nanomaterials for their potential activity against N. gonorrhoeae (ATCC 49226. Silver nanoparticles (Ag NPs, 120 nm showed the greatest potency for reducing N. gonorrhoeae colony formation (MIC: 12.5 µg/ml and possessed the dominant influence on the antibacterial activity with their properties of the nanoparticles within a concentration range that did not induce cytotoxicity in human fibroblasts or epithelial cells. Electron microscopy revealed that the Ag NPs significantly reduced bacterial cell membrane integrity. Furthermore, the use of clinical isolates of multidrug-resistant N. gonorrhoeae showed that combined treatment with 120 nm Ag NPs and cefmetazole produced additive effects. This is the first report to screen the effectiveness of nanomaterials against N. gonorrhoeae, and our results indicate that 120 nm Ag NPs deliver low levels of toxicity to human epithelial cells and could be used as an adjuvant with antibiotic therapy, either for topical use or as a coating for biomaterials, to prevent or treat multidrug-resistant N. gonorrhoeae.

  1. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Science.gov (United States)

    von Burg, Simone; Álvarez-Alfageme, Fernando; Romeis, Jörg

    2012-01-01

    In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici) and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM) mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew) became more favourable for another pest (aphids).

  2. Indirect effect of a transgenic wheat on aphids through enhanced powdery mildew resistance.

    Directory of Open Access Journals (Sweden)

    Simone von Burg

    Full Text Available In agricultural ecosystems, arthropod herbivores and fungal pathogens are likely to colonise the same plant and may therefore affect each other directly or indirectly. The fungus that causes powdery mildew (Blumeria graminis tritici and cereal aphids are important pests of wheat but interactions between them have seldom been investigated. We studied the effects of powdery mildew of wheat on two cereal aphid species, Metopolophium dirhodum and Rhopalosiphum padi. We hypothesized that aphid number and size will be smaller on powdery mildew-infected plants than on non-infected plants. In a first experiment we used six commercially available wheat varieties whereas in the second experiment we used a genetically modified (GM mildew-resistant wheat line and its non-transgenic sister line. Because the two lines differed only in the presence of the transgene and in powdery mildew resistance, experiment 2 avoided the confounding effect of variety. In both experiments, the number of M. dirhodum but not of R. padi was reduced by powdery mildew infection. Transgenic mildew-resistant lines therefore harboured bigger aphid populations than the non-transgenic lines. For both aphid species individual size was mostly influenced by aphid number. Our results indicate that plants that are protected from a particular pest (powdery mildew became more favourable for another pest (aphids.

  3. Advanced core concepts with enhanced proliferation resistance by transmutation of minor actinides

    International Nuclear Information System (INIS)

    Saito, Masaki

    2005-01-01

    ''Protected Plutonium Production (P 3 )'' has been proposed to establish high burn-up cores and to produce protected with high proliferation resistance due to high decay heat and large number of spontaneous fission neutron of 238 Pu by the transmutation of Minor Actinides (MAs) which is presently treated as high-level waste. The burn-up calculations have shown that the advanced fuel with UO 2 (11-13% enrichment of 235 U) by doping 237 Np to produce 238 Pu in the commercialized large LWRs burn up to 100 GWd/t with 238 Pu to Pu ratio of about 20% which means the fuel is highly protected from proliferation. It was also predicted that medium or small size LWR cores with 15-17% enrichment, liquid metal cooled cores, and gas cooled cores added by 1-2% Np could achieve 100 GWd/t burning with bearing high proliferation resistance. The 237 Np mass balance calculations have revealed that more than 20 nuclear P 3 plants of 300 MWe could be supplied with enough 237 Np from the Japanese commercial plants in equilibrium fuel cycles. From the present studies, it is confirmed that MAs are treated as burnable and fertile materials not only to extend the core life but also to improve plutonium proliferation resistance of the future nuclear energy systems instead of their geological disposal or just their burning through fission. (author)

  4. Cholesterol-producing transgenic Caenorhabditis elegans lives longer due to newly acquired enhanced stress resistance

    International Nuclear Information System (INIS)

    Lee, Eun-Young; Shim, Yhong-Hee; Chitwood, David J.; Hwang, Soon Baek; Lee, Junho; Paik, Young-Ki

    2005-01-01

    Because Caenorhabditis elegans lacks several components of the de novo sterol biosynthetic pathway, it requires sterol as an essential nutrient. Supplemented cholesterol undergoes extensive enzymatic modification in C. elegans to form other sterols of unknown function. 7-Dehydrocholesterol reductase (DHCR) catalyzes the reduction of the Δ 7 double bond of sterols and is suspected to be defective in C. elegans, in which the major endogenous sterol is 7-dehydrocholesterol (7DHC). We microinjected a human DHCR expression vector into C. elegans, which was then incorporated into chromosome by γ-radiation. This transgenic C. elegans was named cholegans, i.e., cholesterol-producing C. elegans, because it was able to convert 7DHC into cholesterol. We investigated the effects of changes in sterol composition on longevity and stress resistance by examining brood size, mean life span, UV resistance, and thermotolerance. Cholegans contained 80% more cholesterol than the wild-type control. The brood size of cholegans was reduced by 40% compared to the wild-type control, although the growth rate was not significantly changed. The mean life span of cholegans was increased up to 131% in sterol-deficient medium as compared to wild-type. The biochemical basis for life span extension of cholegans appears to partly result from its acquired resistance against both UV irradiation and thermal stress

  5. Overexpression of Pyrabactin Resistance-Like Abscisic Acid Receptors Enhances Drought, Osmotic, and Cold Tolerance in Transgenic Poplars

    Directory of Open Access Journals (Sweden)

    Jingling Yu

    2017-10-01

    Full Text Available Abscisic acid (ABA has been known participate in a wider range of adaptive responses to diverse environmental abiotic stresses such as drought, osmosis, and low temperatures. ABA signaling is initiated by its receptors PYR/PYL/RCARs, a type of soluble proteins with a conserved START domain which can bind ABA and trigger the downstream pathway. Previously, we discovered that poplar (Populus trichocarpa genome encodes 14 PYR/PYL/RCAR orthologs (PtPYRLs, and two of them, PtPYRL1 and PtPYRL5 have been functionally characterized to positively regulate drought tolerance. However, the physiological function of these ABA receptors in poplar remains uncharacterized. Here, we generated transgenic poplar plants overexpressing PtPYRL1 and PtPYRL5 and found that they exhibited more vigorous growth and produced greater biomass when exposed to drought stress. The improved drought tolerance was positively correlated with the key physiological responses dictated by the ABA signaling pathway, including increase in stomatal closure and decrease in leaf water loss. Further analyses revealed that overexpression lines showed improved capacity in scavenging reactive oxygen species and enhanced the activation of antioxidant enzymes under drought stress. Moreover, overexpression of PtPYRL1 or PtPYRL5 significantly increased the poplar resistance to osmotic and cold stresses. In summary, our results suggest that constitutive expression of PtPYRL1 and PtPYRL5 significantly enhances the resistance to drought, osmotic and cold stresses by positively regulating ABA signaling in poplar.

  6. Current-induced nonuniform enhancement of sheet resistance in A r+ -irradiated SrTi O3

    Science.gov (United States)

    Roy, Debangsu; Frenkel, Yiftach; Davidovitch, Sagi; Persky, Eylon; Haham, Noam; Gabay, Marc; Kalisky, Beena; Klein, Lior

    2017-06-01

    The sheet resistance Rs of A r+ irradiated SrTi O3 in patterns with a length scale of several microns increases significantly below ˜40 K in connection with driving currents exceeding a certain threshold. The initial lower Rs is recovered upon warming with accelerated recovery around 70 and 160 K. Scanning superconducting quantum interference device microscopy shows local irreversible changes in the spatial distribution of the current with a length scale of several microns. We attribute the observed nonuniform enhancement of Rs to the attraction of the charged single-oxygen and dioxygen vacancies by the crystallographic domain boundaries in SrTi O3 . The boundaries, which are nearly ferroelectric below 40 K, are polarized by the local electrical field associated with the driven current and the clustered vacancies which suppress conductivity in their vicinity and yield a noticeable enhancement in the device resistance when the current path width is on the order of the boundary extension. The temperatures of accelerated conductivity recovery are associated with the energy barriers for the diffusion of the two types of vacancies.

  7. Alloying element's substitution in titanium alloy with improved oxidation resistance and enhanced magnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ang-Yang, E-mail: ayyu@imr.ac.cn; Wei, Hua; Hu, Qing-Miao; Yang, Rui

    2017-01-15

    First-principles method is used to characterize segregation and magnetic properties of alloyed Ti/TiO{sub 2}interface. We calculate the segregation energy of the doped Ti/TiO{sub 2} interface to investigate alloying atom's distribution. The oxidation resistance of Ti/TiO{sub 2} interface is enhanced by elements Fe and Ni but reduced by element Co. Magnetism could be produced by alloying elements such as Co, Fe and Ni in the bulk of titanium and the surface of Ti at Ti/TiO{sub 2} interface. The presence of these alloying elements could transform the non-magnetic titanium alloys into magnetic systems. We have also calculated the temperature dependence of magnetic permeability for the doped and pure Ti/TiO{sub 2} interfaces. Alloying effects on the Curie temperature of the Ti/TiO{sub 2} interface have been elaborated. - Highlights: • We consider the segregation of alloying atoms on the Ti(101¯0)/TiO{sub 2}(100) interface. • Alloying the Ti//TiO{sub 2} interface with Fe and Ni has a great advantage of improving the oxidation resistance. • Fe, Co and Nican enhance the magnetic properties of the investigated system. • The variation of permeability with temperature has been presented.

  8. Enhanced resistance in Theobroma cacao against oomycete and fungal pathogens by secretion of phosphatidylinositol-3-phosphate-binding proteins.

    Science.gov (United States)

    Helliwell, Emily E; Vega-Arreguín, Julio; Shi, Zi; Bailey, Bryan; Xiao, Shunyuan; Maximova, Siela N; Tyler, Brett M; Guiltinan, Mark J

    2016-03-01

    The internalization of some oomycete and fungal pathogen effectors into host plant cells has been reported to be blocked by proteins that bind to the effectors' cell entry receptor, phosphatidylinositol-3-phosphate (PI3P). This finding suggested a novel strategy for disease control by engineering plants to secrete PI3P-binding proteins. In this study, we tested this strategy using the chocolate tree Theobroma cacao. Transient expression and secretion of four different PI3P-binding proteins in detached leaves of T. cacao greatly reduced infection by two oomycete pathogens, Phytophthora tropicalis and Phytophthora palmivora, which cause black pod disease. Lesion size and pathogen growth were reduced by up to 85%. Resistance was not conferred by proteins lacking a secretory leader, by proteins with mutations in their PI3P-binding site, or by a secreted PI4P-binding protein. Stably transformed, transgenic T. cacao plants expressing two different PI3P-binding proteins showed substantially enhanced resistance to both P. tropicalis and P. palmivora, as well as to the fungal pathogen Colletotrichum theobromicola. These results demonstrate that secretion of PI3P-binding proteins is an effective way to increase disease resistance in T. cacao, and potentially in other plants, against a broad spectrum of pathogens. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  9. Enhanced mechanical properties and increased corrosion resistance of a biodegradable magnesium alloy by plasma electrolytic oxidation (PEO)

    Energy Technology Data Exchange (ETDEWEB)

    White, Leon; Koo, Youngmi [FIT BEST Laboratory, Engineering Research Center, Department of Chemical, Biological, and Bio Engineering, North Carolina A& T State University, Greensboro, NC 27411 (United States); Neralla, Sudheer [Jet-Hot LLC, Burlington, NC 27215 (United States); Sankar, Jagannathan [FIT BEST Laboratory, Engineering Research Center, Department of Chemical, Biological, and Bio Engineering, North Carolina A& T State University, Greensboro, NC 27411 (United States); Yun, Yeoheung, E-mail: yyun@ncat.edu [FIT BEST Laboratory, Engineering Research Center, Department of Chemical, Biological, and Bio Engineering, North Carolina A& T State University, Greensboro, NC 27411 (United States)

    2016-06-15

    Highlights: • Plasma electrolytic oxidation (PEO) method was developed to control corrosion, porosity, and mechanical property. • Mechanical properties of PEO-coated AZ31 alloys were affected by the different electrolyte. • Mechanical properties and corrosion resistance of PEO-coated AZ31 alloys were compared with uncoated one. - Abstract: We report the enhanced mechanical properties of AZ31 magnesium alloys by plasma electrolytic oxidation (PEO) coating in NaOH, Na{sub 2}SiO{sub 3}, KF and NaH{sub 2}PO{sub 4}·2H{sub 2}O containing electrolytes. Mechanical properties including wear resistance, surface hardness and elastic modulus were increased for PEO-coated AZ31 Mg alloys (PEO-AZ31). DC polarization in Hank's solution indicating that the corrosion resistance significantly increased for PEO-coating in KF-contained electrolyte. Based on these results, the PEO coating method shows promising potential for use in biodegradable implant applications where tunable corrosion and mechanical properties are needed.

  10. Identification of tomato introgression lines with enhanced susceptibility or resistance to infection by parasitic giant dodder (Cuscuta reflexa).

    Science.gov (United States)

    Krause, Kirsten; Johnsen, Hanne R; Pielach, Anna; Lund, Leidulf; Fischer, Karsten; Rose, Jocelyn K C

    2018-02-01

    The parasitic flowering plant genus Cuscuta (dodder) is a parasitic weed that infects many important crops. Once it winds around the shoots of potential host plants and initiates the development of penetration organs, called haustoria, only a few plant species have been shown to deploy effective defense mechanisms to ward off Cuscuta parasitization. However, a notable exception is Solanum lycopersicum (tomato), which exhibits a local hypersensitive reaction when attacked by giant dodder (Cuscuta reflexa). Interestingly, the closely related wild desert tomato, Solanum pennellii, is unable to stop the penetration of its tissue by the C. reflexa haustoria. In this study, we observed that grafting a S. pennellii scion onto the rootstock of the resistant S. lycopersicum did not change the susceptibility phenotype of S. pennellii. This suggests that hormones, or other mobile substances, produced by S. lycopersicum do not induce a defense reaction in the susceptible tissue. Screening of a population of introgression lines harboring chromosome fragments from S. pennellii in the genome of the recurrent parent S. lycopersicum, revealed that most lines exhibit the same defense reaction as shown by the S. lycopersicum parental line. However, several lines showed different responses and exhibited either susceptibility, or cell death that extended considerably beyond the infection site. These lines will be valuable for the future identification of key loci involved in the perception of, and resistance to, C. reflexa and for developing strategies to enhance resistance to infection in crop species. © 2017 Scandinavian Plant Physiology Society.

  11. Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

    Directory of Open Access Journals (Sweden)

    Zongli eHu

    2015-01-01

    Full Text Available Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi technology to partially silence three different genes (FOW2, FRP1 and OPR in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

  12. Enhanced corrosion resistance and biocompatibility of AZ31 Mg alloy using PCL/ZnO NPs via electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jinwoo [Department of Bionanosystem Engineering, Graduate School, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Mousa, Hamouda M. [Department of Bionanosystem Engineering, Graduate School, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Engineering Materials and Mechanical Design, Faculty of Engineering, South Valley University, Qena 83523 (Egypt); Park, Chan Hee, E-mail: biochan@jbnu.ac.kr [Department of Bionanosystem Engineering, Graduate School, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of); Kim, Cheol Sang, E-mail: chskim@jbnu.ac.kr [Department of Bionanosystem Engineering, Graduate School, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Division of Mechanical Design Engineering, Chonbuk National University, Jeonju, Jeonbuk 561-756 (Korea, Republic of)

    2017-02-28

    Highlights: • PCL/ZnO composite coating layer by electrospinning techniques showed the nano-scaled and porous surface structure. • Addition of zinc oxide NPs in the PCL fibers led to enhanced coating adhesion and corrosion resistance. • The composite coated surfaces on Mg substrates improved cell attachment and proliferation. - Abstract: In the efforts to improve corrosion resistance and biocompatibility of magnesium alloys, polycarprolactone (PCL) and zinc oxide nanoparticles (ZnO NPs) composite coatings were applied onto AZ31 Mg alloys via electrospinning technique in this study. The PCL/ZnO composite coatings on Mg alloys were characterized by using FE-SEM, EDX, XPS, and FT-IR. Moreover, coating adhesion test, electrochemical corrosion test, and biocompatibility test in vitro were performed to measure coating performance. Our results revealed that the increase in the content of ZnO NPs in the composite coatings not only improved the coating adhesion of composite coatings on Mg alloys, but also increased the corrosion resistance. Furthermore, the biocompatibility of MC3T3-E1 osteoblasts of the PCL/ZnO composite coated samples was superior to the biocompatibility of the bare samples. Such data suggest that applying PCL/ZnO composite coating to the magnesium alloys has suitable potential in biomedical applications.

  13. Investigation of the Use of Laser Shock Peening for Enhancing Fatigue and Stress Corrosion Cracking Resistance of Nuclear Energy Materials

    Energy Technology Data Exchange (ETDEWEB)

    Vasudevan, Vijay K. [Univ. of Cincinnati, OH (United States); Jackson, John [Idaho National Lab. (INL), Idaho Falls, ID (United States); Teysseyre, Sebastien [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alexandreanu, Bogdan [Argonne National Lab. (ANL), Argonne, IL (United States); Chen, Yiren [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-03-07

    The objective of this project, which includes close collaboration with scientists from INL and ANL, is to investigate and demonstrate the use of advanced mechanical surface treatments like laser shock peening (LSP) and ultrasonic nanocrystal surface modification (UNSM) and establish baseline parameters for enhancing the fatigue properties and SCC resistance of nuclear materials like nickel-based alloy 600 and 304 stainless steel. The research program includes the following key elements/tasks: 1) Procurement of Alloy 600 and 304 SS, heat treatment studies; 2) LSP and UNSM processing of base metal and welds/HAZ of alloys 600 and 304; (3) measurement and mapping of surface and sub-surface residual strains/stresses and microstructural changes as a function of process parameters using novel methods; (4) determination of thermal relaxation of residual stresses (macro and micro) and microstructure evolution with time at high temperatures typical of service conditions and modeling of the kinetics of relaxation; (5) evaluation of the effects of residual stress, near surface microstructure and temperature on SCC and fatigue resistance and associated microstructural mechanisms; and (6) studies of the effects of bulk and surface grain boundary engineering on improvements in the SCC resistance and associated microstructural and cracking mechanisms

  14. Down-regulation of Fusarium oxysporum endogenous genes by Host-Delivered RNA interference enhances disease resistance

    Science.gov (United States)

    Hu, Zongli; Parekh, Urvi; Maruta, Natsumi; Trusov, Yuri; Botella, Jimmy

    2015-01-01

    Fusarium oxysporum is a devastating pathogen causing extensive yield losses in a variety of crops and development of sustainable, environmentally friendly methods to improve crop resistance is crucial. We have used Host-Derived RNA interference (HD-RNAi) technology to partially silence three different genes (FOW2, FRP1 and OPR) in the hemi-biotrophic fungus Fusarium oxysporum f. sp. conglutinans. Expression of double stranded RNA molecules targeting fungal pathogen genes was achieved in a number of transgenic Arabidopsis lines. F. oxysporum infecting the transgenic lines displayed substantially reduced mRNA levels on all three targeted genes, with an average of 75%, 83% and 72% reduction for FOW2, FRP1 and OPR respectively. The silencing of pathogen genes had a clear positive effect on the ability of the transgenic lines to fight infection. All transgenic lines displayed enhanced resistance to F. oxysporum with delayed disease symptom development, especially FRP1 and OPR lines. Survival rates after fungal infection were higher in the transgenic lines compared to control wild type plants which consistently showed survival rates of 10%, with FOW2 lines showing 25% survival; FRP1 lines 30-50% survival and FOW2 between 45-70% survival. The down-regulation effect was specific for the targeted genes without unintended effects in related genes. In addition to producing resistant crops, HD-RNAi can provide a useful tool to rapidly screen candidate fungal pathogenicity genes without the need to produce fungal knockout mutants.

  15. Enhanced corrosion resistance and biocompatibility of AZ31 Mg alloy using PCL/ZnO NPs via electrospinning

    International Nuclear Information System (INIS)

    Kim, Jinwoo; Mousa, Hamouda M.; Park, Chan Hee; Kim, Cheol Sang

    2017-01-01

    Highlights: • PCL/ZnO composite coating layer by electrospinning techniques showed the nano-scaled and porous surface structure. • Addition of zinc oxide NPs in the PCL fibers led to enhanced coating adhesion and corrosion resistance. • The composite coated surfaces on Mg substrates improved cell attachment and proliferation. - Abstract: In the efforts to improve corrosion resistance and biocompatibility of magnesium alloys, polycarprolactone (PCL) and zinc oxide nanoparticles (ZnO NPs) composite coatings were applied onto AZ31 Mg alloys via electrospinning technique in this study. The PCL/ZnO composite coatings on Mg alloys were characterized by using FE-SEM, EDX, XPS, and FT-IR. Moreover, coating adhesion test, electrochemical corrosion test, and biocompatibility test in vitro were performed to measure coating performance. Our results revealed that the increase in the content of ZnO NPs in the composite coatings not only improved the coating adhesion of composite coatings on Mg alloys, but also increased the corrosion resistance. Furthermore, the biocompatibility of MC3T3-E1 osteoblasts of the PCL/ZnO composite coated samples was superior to the biocompatibility of the bare samples. Such data suggest that applying PCL/ZnO composite coating to the magnesium alloys has suitable potential in biomedical applications.

  16. Enhancement of optical transmittance and electrical resistivity of post-annealed ITO thin films RF sputtered on Si

    Science.gov (United States)

    Ali, Ahmad Hadi; Hassan, Zainuriah; Shuhaimi, Ahmad

    2018-06-01

    This paper reports on the enhancement of optical transmittance and electrical resistivity of indium tin oxide (ITO) transparent conductive oxides (TCO) deposited by radio frequency (RF) sputtering on Si substrate. Post-annealing was conducted on the samples at temperature ranges of 500-700 °C. From X-ray diffraction analysis (XRD), ITO (2 2 2) peak was observed after post-annealing indicating crystallization phase of the films. From UV-vis measurements, the ITO thin film shows highest transmittance of more than 90% at post-annealing temperature of 700 °C as compared to the as-deposited thin films. From atomic force microscope (AFM), the surface roughness becomes smoother after post-annealing as compared to the as-deposited. The lowest electrical resistivity for ITO sample is 6.68 × 10-4 Ω cm after post-annealed at 700 °C that are contributed by high carrier concentration and mobility. The improved structural and surface morphological characteristics helps in increasing the optical transmittance and reducing the electrical resistivity of the ITO thin films.

  17. Diamond-like carbon coatings enhance scratch resistance of bearing surfaces for use in joint arthroplasty: hard substrates outperform soft.

    Science.gov (United States)

    Roy, Marcel E; Whiteside, Leo A; Katerberg, Brian J

    2009-05-01

    The purpose of this study was to test the hypotheses that diamond-like carbon (DLC) coatings will enhance the scratch resistance of a bearing surface in joint arthroplasty, and that a hard ceramic substrate will further enhance scratch resistance by reducing plastic deformation. We tested these hypotheses by applying a hard DLC coating to medical-grade cobalt chromium alloy (CoCr) and magnesia-stabilized zirconia (Mg-PSZ) femoral heads and performing scratch tests to determine the loads required to cause cohesive and adhesive fracture of the coating. Scratch tracks of DLC-coated and noncoated heads were then scanned by optical profilometry to determine scratch depth, width, and pile-up (raised edges), as measures of susceptibility to scratching. DLC-coated CoCr specimens exhibited cohesive coating fracture as wedge spallation at an average load of 9.74 N, whereas DLC-coated Mg-PSZ exhibited cohesive fracture as arc-tensile cracks and chipping at a significantly higher average load of 41.3 N (p coating fracture, DLC-CoCr delaminated at an average load of 35.2 N, whereas DLC-Mg-PSZ fractured by recovery spallation at a significantly higher average load of 46.8 N (p DLC-CoCr and DLC-Mg-PSZ specimens exhibited significantly shallower scratches and less pile-up than did uncoated specimens (p DLC-Mg-PSZ better resisted plastic deformation, requiring significantly higher loads for cohesive and adhesive coating fracture. These findings supported both of our hypotheses. (c) 2008 Wiley Periodicals, Inc.

  18. Resistive heating enhanced soil vapor extraction of chlorinated solvents from trichloroethylene contaminated silty, low permeable soil

    NARCIS (Netherlands)

    Zutphen, M. van; Heron, G.; Enfield, C.G.; Christensen, T.H.

    1998-01-01

    A 2D-laboratory box experiment (12 x 56 x 116 cm) was conducted to simulate the enhancement of soil vapor extraction by the application of low frequency electrical heating Uoule heating) for the remediation of a low permeable, silty soil contaminated with trichloroethylene. Joule heating enlarged

  19. Enhanced coagulation activation in preeclampsia: the role of APC resistance, microparticles and other plasma constituents

    NARCIS (Netherlands)

    VanWijk, Marja J.; Boer, Kees; Berckmans, René J.; Meijers, Joost C. M.; van der Post, Joris A. M.; Sturk, Augueste; VanBavel, Ed; Nieuwland, Rienk

    2002-01-01

    Coagulation activation in pregnancy is further enhanced in preeclampsia. We investigated whether this results from increased thrombin generation by the plasma itself or its cell-derived microparticles. Plasma samples were obtained from preeclamptic, normal pregnant and nonpregnant women (each n =

  20. CYP 2E1 mutant mice are resistant to DDC-induced enhancement of MPTP toxicity.

    Science.gov (United States)

    Viaggi, C; Vaglini, F; Pardini, C; Sgadò, P; Caramelli, A; Corsini, G U

    2007-01-01

    In order to reach a deeper insight into the mechanism of diethyldithiocarbamate (DDC)-induced enhancement of MPTP toxicity in mice, we showed that CYP450 (2E1) inhibitors, such as diallyl sulfide (DAS) or phenylethylisothiocyanate (PIC), also potentiate the selective DA neuron degeneration in C57/bl mice. Furthermore we showed that CYP 2E1 is present in the brain and in the basal ganglia of mice (Vaglini et al., 2004). However, because DAS and PIC are not selective CYP 2E1 inhibitors and in order to provide direct evidence for CYP 2E1 involvement in the enhancement of MPTP toxicity, CYP 2E1 knockout mice (GONZ) and wild type animals (SVI) of the same genetic background were treated with MPTP or the combined DDC + MPTP treatment. In CYP 2E1 knockout mice, DDC pretreatment completely fails to enhance MPTP toxicity, although enhancement of MPTP toxicity was regularly present in the SVI control animals. The immunohistochemical study confirms our results and suggests that CYP 2E1 may have a detoxifying role.

  1. Enhancement of wear and ballistic resistance of armour grade AA7075 aluminium alloy using friction stir processing

    Directory of Open Access Journals (Sweden)

    I. Sudhakar

    2015-03-01

    Full Text Available Industrial applications of aluminium and its alloys are restricted because of their poor tribological properties. Thermal spraying, laser surfacing, electron beam welding are the most widely used techniques to alter the surface morphology of base metal. Preliminary studies reveal that the coating and layering of aluminium alloys with ceramic particles enhance the ballistic resistance. Furthermore, among aluminium alloys, 7075 aluminium alloy exhibits high strength which can be compared to that of steels and has profound applications in the designing of lightweight fortification structures and integrated protection systems. Having limitations such as poor bond integrity, formation of detrimental phases and interfacial reaction between reinforcement and substrate using fusion route to deposit hard particles paves the way to adopt friction stir processing for fabricating surface composites using different sizes of boron carbide particles as reinforcement on armour grade 7075 aluminium alloy as matrix in the present investigation. Wear and ballistic tests were carried out to assess the performance of friction stir processed AA7075 alloy. Significant improvement in wear resistance of friction stir processed surface composites is attributed to the change in wear mechanism from abrasion to adhesion. It has also been observed that the surface metal matrix composites have shown better ballistic resistance compared to the substrate AA7075 alloy. Addition of solid lubricant MoS2 has reduced the depth of penetration of the projectile to half that of base metal AA7075 alloy. For the first time, the friction stir processing technique was successfully used to improve the wear and ballistic resistances of armour grade high strength AA7075 alloy.

  2. Phage “delay” towards enhancing bacterial escape from biofilms: a more comprehensive way of viewing resistance to bacteriophages

    Directory of Open Access Journals (Sweden)

    Stephen T. Abedon

    2017-03-01

    Full Text Available In exploring bacterial resistance to bacteriophages, emphasis typically is placed on those mechanisms which completely prevent phage replication. Such resistance can be detected as extensive reductions in phage ability to form plaques, that is, reduced efficiency of plating. Mechanisms include restriction-modification systems, CRISPR/Cas systems, and abortive infection systems. Alternatively, phages may be reduced in their “vigor” when infecting certain bacterial hosts, that is, with phages displaying smaller burst sizes or extended latent periods rather than being outright inactivated. It is well known, as well, that most phages poorly infect bacteria that are less metabolically active. Extracellular polymers such as biofilm matrix material also may at least slow phage penetration to bacterial surfaces. Here I suggest that such “less-robust” mechanisms of resistance to bacteriophages could serve bacteria by slowing phage propagation within bacterial biofilms, that is, delaying phage impact on multiple bacteria rather than necessarily outright preventing such impact. Related bacteria, ones that are relatively near to infected bacteria, e.g., roughly 10+ µm away, consequently may be able to escape from biofilms with greater likelihood via standard dissemination-initiating mechanisms including erosion from biofilm surfaces or seeding dispersal/central hollowing. That is, given localized areas of phage infection, so long as phage spread can be reduced in rate from initial points of contact with susceptible bacteria, then bacterial survival may be enhanced due to bacteria metaphorically “running away” to more phage-free locations. Delay mechanisms—to the extent that they are less specific in terms of what phages are targeted—collectively could represent broader bacterial strategies of phage resistance versus outright phage killing, the latter especially as require specific, evolved molecular recognition of phage presence. The

  3. Darker eggs of mosquitoes resist more to dry conditions: Melanin enhances serosal cuticle contribution in egg resistance to desiccation in Aedes, Anopheles and Culex vectors.

    Science.gov (United States)

    Farnesi, Luana C; Vargas, Helena C M; Valle, Denise; Rezende, Gustavo L

    2017-10-01

    Mosquito vectors lay their white eggs in the aquatic milieu. During early embryogenesis water passes freely through the transparent eggshell, which at this moment is composed of exochorion and endochorion. Within two hours the endochorion darkens via melanization but even so eggs shrink and perish if removed from moisture. However, during mid-embryogenesis, cells of the extraembryonic serosa secrete the serosal cuticle, localized right below the endochorion, becoming the third and innermost eggshell layer. Serosal cuticle formation greatly reduces water flow and allows egg survival outside the water. The degree of egg resistance to desiccation (ERD) at late embryogenesis varies among different species: Aedes aegypti, Anopheles aquasalis and Culex quinquefasciatus eggs can survive in a dry environment for ≥ 72, 24 and 5 hours, respectively. In some adult insects, darker-body individuals show greater resistance to desiccation than lighter ones. We asked if egg melanization enhances mosquito serosal cuticle-dependent ERD. Species with higher ERD at late embryogenesis exhibit more melanized eggshells. The melanization-ERD hypothesis was confirmed employing two Anopheles quadrimaculatus strains, the wild type and the mutant GORO, with a dark-brown and a golden eggshell, respectively. In all cases, serosal cuticle formation is fundamental for the establishment of an efficient ERD but egg viability outside the water is much higher in mosquitoes with darker eggshells than in those with lighter ones. The finding that pigmentation influences egg water balance is relevant to understand the evolutionary history of insect egg coloration. Since eggshell and adult cuticle pigmentation ensure insect survivorship in some cases, they should be considered regarding species fitness and novel approaches for vector or pest insects control.

  4. Bioactive glass-ceramic coating for enhancing the in vitro corrosion resistance of biodegradable Mg alloy

    Science.gov (United States)

    Ye, Xinyu; Cai, Shu; Dou, Ying; Xu, Guohua; Huang, Kai; Ren, Mengguo; Wang, Xuexin

    2012-10-01

    In this work, a bioactive 45S5 glass-ceramic coating was synthesized on magnesium (Mg) alloy substrate by using a sol-gel dip-coating method, to improve the initial corrosion resistance of AZ31 Mg alloy. The surface morphology and phase composition of the glass-ceramic coating were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The coating composed of amorphous phase and crystalline phase Na2Ca2Si3O9, with the thickness of ∼1.0 μm, exhibited a uniform and crack-free surface morphology. The corrosion behavior of the uncoated and coated Mg alloy substrates was investigated by the electrochemical measurements and immersion tests in simulated body fluid (SBF). Potentiodynamic polarization tests recorded an increase of potential (Ecorr) form -1.60 V to -1.48 V, and a reduction of corrosion current density (icorr) from 4.48 μA cm-2 to 0.16 μA cm-2, due to the protection provided by the glass-ceramic coating. Immersion tests also showed the markedly improved corrosion resistance of the coated sample over the immersion period of 7 days. Moreover, after 14 days of immersion in SBF, the corrosion resistance of the coated sample declined due to the cracking of the glass-ceramic coating, which was confirmed by electrochemical impedance spectroscopy (EIS) analysis. The results suggested that the 45S5 glass-ceramic coated Mg alloy could provide a suitable corrosion behavior for use as degradable implants.

  5. Menadione Sodium Bisulphite (MSB) enhances the resistance response of tomato, leading to repel mollusc pests.

    Science.gov (United States)

    Carrillo-Perdomo, Estefanía; Jiménez-Arias, David; Aller, Ángel; Borges, Andrés A

    2016-05-01

    Snails and slugs are terrestrial gastropods representing an important biotic stress that adversely affects crop yields. These pests are typically controlled with molluscicides, which produce pollution and toxicity and further induce the evolution of resistance mechanisms, making pest management even more challenging. In our work, we have assessed the efficacy of two different plant defence activators, menadione sodium bisulphite (MSB) and 1,2,3-benzothiadiazole-7-thiocarboxylic acid S-methyl ester (BTH), as inducers of resistance mechanisms of the model plant for defence, Solanum lycopersicum, against the generalist mollusc Theba grasseti (Helicidae). The study was designed to test the feeding behaviour and choice of snails, and also to analyse the expression profile of different genes specifically involved in defence against herbivores and wounds. Our data suggest that, through the downregulation of the terpene volatile genes and the production of proteinase inhibitors, treated MSB plants may be less apparent to herbivores that use herbivore-induced plant volatiles for host location. By contrast, BTH was not effective in the treatment of the pest, probably owing to an antagonistic effect derived from the induction of both salicylic-acid-dependent and jasmonic-acid-dependent pathways. This information is crucial to determine the genetic basis of the choice of terrestrial gastropod herbivores in tomato, providing valuable insight into how the plant defence activators could control herbivore pests in plants. Our work not only reports for the first time the interaction between tomato and a mollusc pest but also presents the action of two plant defence inductors that seems to produce opposed responses by inducing resistance mechanisms through different defence pathways. © 2015 Society of Chemical Industry.

  6. Overexpression of a defensin enhances resistance to a fruit-specific anthracnose fungus in pepper.

    Directory of Open Access Journals (Sweden)

    Hyo-Hyoun Seo

    Full Text Available Functional characterization of a defensin, J1-1, was conducted to evaluate its biotechnological potentiality in transgenic pepper plants against the causal agent of anthracnose disease, Colletotrichum gloeosporioides. To determine antifungal activity, J1-1 recombinant protein was generated and tested for the activity against C. gloeosporioides, resulting in 50% inhibition of fungal growth at a protein concentration of 0.1 mg·mL-1. To develop transgenic pepper plants resistant to anthracnose disease, J1-1 cDNA under the control of 35S promoter was introduced into pepper via Agrobacterium-mediated genetic transformation method. Southern and Northern blot analyses confirmed that a single copy of the transgene in selected transgenic plants was normally expressed and also stably transmitted to subsequent generations. The insertion of T-DNA was further analyzed in three independent homozygous lines using inverse PCR, and confirmed the integration of transgene in non-coding region of genomic DNA. Immunoblot results showed that the level of J1-1 proteins, which was not normally accumulated in unripe fruits, accumulated high in transgenic plants but appeared to differ among transgenic lines. Moreover, the expression of jasmonic acid-biosynthetic genes and pathogenesis-related genes were up-regulated in the transgenic lines, which is co-related with the resistance of J1-1 transgenic plants to anthracnose disease. Consequently, the constitutive expression of J1-1 in transgenic pepper plants provided strong resistance to the anthracnose fungus that was associated with highly reduced lesion formation and fungal colonization. These results implied the significance of the antifungal protein, J1-1, as a useful agronomic trait to control fungal disease.

  7. Overexpression of a defensin enhances resistance to a fruit-specific anthracnose fungus in pepper.

    Science.gov (United States)

    Seo, Hyo-Hyoun; Park, Sangkyu; Park, Soomin; Oh, Byung-Jun; Back, Kyoungwhan; Han, Oksoo; Kim, Jeong-Il; Kim, Young Soon

    2014-01-01

    Functional characterization of a defensin, J1-1, was conducted to evaluate its biotechnological potentiality in transgenic pepper plants against the causal agent of anthracnose disease, Colletotrichum gloeosporioides. To determine antifungal activity, J1-1 recombinant protein was generated and tested for the activity against C. gloeosporioides, resulting in 50% inhibition of fungal growth at a protein concentration of 0.1 mg·mL-1. To develop transgenic pepper plants resistant to anthracnose disease, J1-1 cDNA under the control of 35S promoter was introduced into pepper via Agrobacterium-mediated genetic transformation method. Southern and Northern blot analyses confirmed that a single copy of the transgene in selected transgenic plants was normally expressed and also stably transmitted to subsequent generations. The insertion of T-DNA was further analyzed in three independent homozygous lines using inverse PCR, and confirmed the integration of transgene in non-coding region of genomic DNA. Immunoblot results showed that the level of J1-1 proteins, which was not normally accumulated in unripe fruits, accumulated high in transgenic plants but appeared to differ among transgenic lines. Moreover, the expression of jasmonic acid-biosynthetic genes and pathogenesis-related genes were up-regulated in the transgenic lines, which is co-related with the resistance of J1-1 transgenic plants to anthracnose disease. Consequently, the constitutive expression of J1-1 in transgenic pepper plants provided strong resistance to the anthracnose fungus that was associated with highly reduced lesion formation and fungal colonization. These results implied the significance of the antifungal protein, J1-1, as a useful agronomic trait to control fungal disease.

  8. Enhancement of the oxidation resistance of carbon fibres in C/C composites via surface treatments

    Energy Technology Data Exchange (ETDEWEB)

    Labruquere, S.; Pailler, R.; Naslain, R. [Bordeaux Univ., Pessac (France). Lab. des Composites Thermostructuraux; Desbat, B. [Lab. de Spectroscopie Moleculaire et Cristalline, Univ. of Bordeaux, Talence (France)

    1997-12-31

    Carbon-carbon (C/C) composites are commonly used in rockets and braking systems. However, the carbon reacts with oxygen, burning away rapidly at temperatures as low as 450 C. This work deals with the protection of carbon fibres from oxidation between 600 and 1000 C. Two kinds of methods were investigated to protect carbon fibres: (i) surface treatment with aqueous solutions (e.g. of H3PO4) and (ii) chemical vapour deposition (CVD) of SiC coatings. Oxidation resistance of the as treated preforms was studied under dry air atmosphere. (orig.) 2 refs.

  9. Bioactive glass-ceramic coating for enhancing the in vitro corrosion resistance of biodegradable Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Ye Xinyu [Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Cai Shu, E-mail: caishu@tju.edu.cn [Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Dou Ying [Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China); Xu Guohua [Shanghai Changzheng Hospital, Shanghai 200003 (China); Huang Kai; Ren Mengguo; Wang Xuexin [Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, Tianjin University, Tianjin 300072 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer Sol-gel derived 45S5 glass-ceramic coating was prepared on Mg alloy substrate. Black-Right-Pointing-Pointer The corrosion resistance of glass-ceramic coated Mg alloy was markedly improved. Black-Right-Pointing-Pointer The corrosion behavior of the coated sample varied due to the cracking of coating. - Abstract: In this work, a bioactive 45S5 glass-ceramic coating was synthesized on magnesium (Mg) alloy substrate by using a sol-gel dip-coating method, to improve the initial corrosion resistance of AZ31 Mg alloy. The surface morphology and phase composition of the glass-ceramic coating were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The coating composed of amorphous phase and crystalline phase Na{sub 2}Ca{sub 2}Si{sub 3}O{sub 9}, with the thickness of {approx}1.0 {mu}m, exhibited a uniform and crack-free surface morphology. The corrosion behavior of the uncoated and coated Mg alloy substrates was investigated by the electrochemical measurements and immersion tests in simulated body fluid (SBF). Potentiodynamic polarization tests recorded an increase of potential (E{sub corr}) form -1.60 V to -1.48 V, and a reduction of corrosion current density (i{sub corr}) from 4.48 {mu}A cm{sup -2} to 0.16 {mu}A cm{sup -2}, due to the protection provided by the glass-ceramic coating. Immersion tests also showed the markedly improved corrosion resistance of the coated sample over the immersion period of 7 days. Moreover, after 14 days of immersion in SBF, the corrosion resistance of the coated sample declined due to the cracking of the glass-ceramic coating, which was confirmed by electrochemical impedance spectroscopy (EIS) analysis. The results suggested that the 45S5 glass-ceramic coated Mg alloy could provide a suitable corrosion behavior for use as degradable implants.

  10. Overexpression of TiERF1 enhances resistance to sharp eyespot in transgenic wheat

    OpenAIRE

    Chen, Liang; Zhang, ZengYan; Liang, HongXia; Liu, HongXia; Du, LiPu; Xu, Huijun; Xin, Zhiyong

    2008-01-01

    Wheat sharp eyespot, primarily caused by a soil-borne fungus Rhizoctonia cerealis, has become one of the most serious diseases of wheat in China. In this study, an ethylene response factor (ERF) gene from a wheat relative Thinopyrum intermedium, TiERF1, was characterized further, transgenic wheat lines expressing TiERF1 were developed, and the resistance of the transgenic wheat lines against R. cerealis was investigated. Southern blotting analysis indicated that at least two copies of the TiE...

  11. Polyamide desalination membrane characterization and surface modification to enhance fouling resistance.

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mukul M. (Univeristy of Texas at Austin, Austin, TX); Freeman, Benny D. (Univeristy of Texas at Austin, Austin, TX); Van Wagner, Elizabeth M. (Univeristy of Texas at Austin, Austin, TX); Hickner, Michael A. (Pennsylvania State University, University Park, PA); Altman, Susan Jeanne

    2010-08-01

    The market for polyamide desalination membranes is expected to continue to grow during the coming decades. Purification of alternative water sources will also be necessary to meet growing water demands. Purification of produced water, a byproduct of oil and gas production, is of interest due to its dual potential to provide water for beneficial use as well as to reduce wastewater disposal costs. However, current polyamide membranes are prone to fouling, which decreases water flux and shortens membrane lifetime. This research explored surface modification using poly(ethylene glycol) diglycidyl ether (PEGDE) to improve the fouling resistance of commercial polyamide membranes. Characterization of commercial polyamide membrane performance was a necessary first step before undertaking surface modification studies. Membrane performance was found to be sensitive to crossflow testing conditions. Concentration polarization and feed pH strongly influenced NaCl rejection, and the use of continuous feed filtration led to higher water flux and lower NaCl rejection than was observed for similar tests performed using unfiltered feed. Two commercial polyamide membranes, including one reverse osmosis and one nanofiltration membrane, were modified by grafting PEGDE to their surfaces. Two different PEG molecular weights (200 and 1000) and treatment concentrations (1% (w/w) and 15% (w/w)) were studied. Water flux decreased and NaCl rejection increased with PEGDE graft density ({micro}g/cm{sup 2}), although the largest changes were observed for low PEGDE graft densities. Surface properties including hydrophilicity, roughness and charge were minimally affected by surface modification. The fouling resistance of modified and unmodified membranes was compared in crossflow filtration studies using model foulant solutions consisting of either a charged surfactant or an oil in water emulsion containing n-decane and a charged surfactant. Several PEGDE-modified membranes demonstrated improved

  12. Resistance training enhances muscular performance in patients with anorexia nervosa: A randomized controlled trial

    OpenAIRE

    Fernández del Valle, María; Larumbe Zabala, Eneko; Villaseñor Montarroso, Ángel; Cardona González, Claudia Andrea; Díez Vega, Ignacio; López Mojares, Luis Miguel; Pérez Ruiz, Margarita

    2014-01-01

    OBJECTIVE: Low-intensity exercise applied in anorexia nervosa patients has been shown to have a harmless effect on body composition and to effect short-term improvements in muscular strength and agility. The aim of this study was to determine the effects of a high-intensity resistance training program designed for adolescents to improve strength and agility in anorexia nervosa restricting-type patients (AN-R). METHODS: From a total of 36 female patients with AN-R, one group (interven...

  13. The enhanced corrosion resistance of UMAO coatings on Mg by silane treatment

    Directory of Open Access Journals (Sweden)

    Muqin Li

    2014-10-01

    Full Text Available The surface silanization was carried out on ultrasonic micro-arc oxidation (UMAO coatings on pure magnesium using KH550 as silane coupling agent (SCA. The surface morphology, chemical bonds and corrosion resistance of the silane films were investigated by scanning electron microscope (SEM, Fourier transform infrared spectroscopy (FTIR and electrochemical workstation, respectively. The results showed that hybrid coatings were successfully prepared on pure magnesium by UMAO-NaOH (1 mol/L, 2 mol/L, 3 mol/L-SCA processing. The organic films with Si–O–Mg bonds are helpful for the reduction of the pores in UMAO coatings. The pores decreased with increasing NaOH concentration. Compared with single UMAO treatment, the corrosion potentials (Ecorr of magnesium plates with UMAO-NaOH (1 mol/L, 2 mol/L, 3 mol/L-SCA treatment increased by 29 mV, 53 mV and 75 mV, respectively, meanwhile the corrosion current density (Icorr reduced one to two orders of magnitude. It indicated that the corrosion resistance of the coatings was improved by silane treatment.

  14. Do metabolites that are produced during resistance exercise enhance muscle hypertrophy?

    Science.gov (United States)

    Dankel, Scott J; Mattocks, Kevin T; Jessee, Matthew B; Buckner, Samuel L; Mouser, J Grant; Loenneke, Jeremy P

    2017-11-01

    Many reviews conclude that metabolites play an important role with respect to muscle hypertrophy during resistance exercise, but their actual physiologic contribution remains unknown. Some have suggested that metabolites may work independently of muscle contraction, while others have suggested that metabolites may play a secondary role in their ability to augment muscle activation via inducing fatigue. Interestingly, the studies used as support for an anabolic role of metabolites use protocols that are not actually designed to test the importance of metabolites independent of muscle contraction. While there is some evidence in vitro that metabolites may induce muscle hypertrophy, the only study attempting to answer this question in humans found no added benefit of pooling metabolites within the muscle post-exercise. As load-induced muscle hypertrophy is thought to work via mechanotransduction (as opposed to being metabolically driven), it seems likely that metabolites simply augment muscle activation and cause the mechanotransduction cascade in a larger proportion of muscle fibers, thereby producing greater muscle growth. A sufficient time under tension also appears necessary, as measurable muscle growth is not observed after repeated maximal testing. Based on current evidence, it is our opinion that metabolites produced during resistance exercise do not have anabolic properties per se, but may be anabolic in their ability to augment muscle activation. Future studies are needed to compare protocols which produce similar levels of muscle activation, but differ in the magnitude of metabolites produced, or duration in which the exercised muscles are exposed to metabolites.

  15. Enhancing wear resistance of working bodies of grinder through lining crushed material

    Science.gov (United States)

    Romanovich, A. A.; Annenko, D. M.; Romanovich, M. A.; Apukhtina, I. V.

    2018-03-01

    The article presents the analysis of directions of increasing wear resistance of working surfaces of rolls. A technical solution developed at the level of the invention is proposed, which is simple to implement in production conditions and which makes it possible to protect the roll surface from heavy wear due to surfacing of wear-resistant mesh material, cells of which are filling with grinding material in the process of work. Retaining them enables one to protect the roll surface from wear. The paper dwells on conditions of pressing materials in cells of eccentric rolls on the working surface with a grid of rectangular shape. The paper presents an equation for calculation of the cell dimension that provides the lining of the working surface by a mill material with respect to its properties. The article presents results of comparative studies on the grinding process of a press roller grinder (PRG) between rolls with and without a fusion-bonded mesh. It is clarified that the lining of rolls working surface slightly reduces the quality of the grinding, since the material thickness in the cell is small and has a finely divided and compacted structure with high strength.

  16. Molecular carbon nitride ion beams for enhanced corrosion resistance of stainless steel

    Science.gov (United States)

    Markwitz, A.; Kennedy, J.

    2017-10-01

    A novel approach is presented for molecular carbon nitride beams to coat stainless surfaces steel using conventional safe feeder gases and electrically conductive sputter targets for surface engineering with ion implantation technology. GNS Science's Penning type ion sources take advantage of the breaking up of ion species in the plasma to assemble novel combinations of ion species. To test this phenomenon for carbon nitride, mixtures of gases and sputter targets were used to probe for CN+ ions for simultaneous implantation into stainless steel. Results from mass analysed ion beams show that CN+ and a variety of other ion species such as CNH+ can be produced successfully. Preliminary measurements show that the corrosion resistance of stainless steel surfaces increased sharply when implanting CN+ at 30 keV compared to reference samples, which is interesting from an application point of view in which improved corrosion resistance, surface engineering and short processing time of stainless steel is required. The results are also interesting for novel research in carbon-based mesoporous materials for energy storage applications and as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost.

  17. Enhanced biocorrosion resistance and biocompatibility of degradable Mg-Nd-Zn-Zr alloy by brushite coating.

    Science.gov (United States)

    Niu, Jialin; Yuan, Guangyin; Liao, Yi; Mao, Lin; Zhang, Jian; Wang, Yongping; Huang, Feng; Jiang, Yao; He, Yaohua; Ding, Wenjiang

    2013-12-01

    To further improve the corrosion resistance and biocompatibility of Mg-Nd-Zn-Zr alloy (JDBM), a biodegradable calcium phosphate coating (Ca-P coating) with high bonding strength was developed using a novel chemical deposition method. The main composition of the Ca-P coating was brushite (CaHPO4·2H2O). The bonding strength between the coating and the JDBM substrate was measured to be over 10 MPa, and the thickness of the coating layer was about 10-30 μm. The in vitro corrosion tests indicated that the Ca-P treatment improved the corrosion resistance of JDBM alloy in Hank's solution. Ca-P treatment significantly reduced the hemolysis rate of JDBM alloy from 48% to 0.68%, and induced no toxicity to MC3T3-E1 cells. The in vivo implantation experiment in New Zealand's rabbit tibia showed that the degradation rate was reduced obviously by the Ca-P treatment and less gas was produced from Ca-P treated JDBM bone plates and screws in early stage of the implantation, and at least 10weeks degradation time can be prolonged by the present coating techniques. Both Ca-P treated and untreated JDBM Mg alloy induced bone growth. The primary results indicate that the present Ca-P treatment is a promising technique for the degradable Mg-based biomaterials for orthopedic applications. © 2013.

  18. Hierarchically ordered self-lubricating superhydrophobic anodized aluminum surfaces with enhanced corrosion resistance.

    Science.gov (United States)

    Vengatesh, Panneerselvam; Kulandainathan, Manickam Anbu

    2015-01-28

    Herein, we report a facile method for the fabrication of self-lubricating superhydrophobic hierarchical anodic aluminum oxide (AAO) surfaces with improved corrosion protection, which is greatly anticipated to have a high impact in catalysis, aerospace, and the shipping industries. This method involves chemical grafting of as-formed AAO using low surface free energy molecules like long chain saturated fatty acids, perfluorinated fatty acid (perfluorooctadecanoic acid, PFODA), and perfluorosulfonicacid-polytetrafluoroethylene copolymer. The pre and post treatment processes in the anodization of aluminum (Al) play a vital role in the grafting of fatty acids. Wettability and surface free energy were analyzed using a contact angle meter and achieved 161.5° for PFODA grafted anodized aluminum (PFODA-Al). This study was also aimed at evaluating the surface for corrosion resistance by Tafel polarization and self-lubricating properties by tribological studies using a pin-on-disc tribometer. The collective results showed that chemically grafted AAO nanostructures exhibit high corrosion resistance toward seawater and low frictional coefficient due to low surface energy and self-lubricating property of fatty acids covalently linked to anodized Al surfaces.

  19. Enhanced Corrosion Resistance of PVD-CrN Coatings by ALD Sealing Layers

    Science.gov (United States)

    Wan; Zhang, Teng Fei; Ding, Ji Cheng; Kim, Chang-Min; Park, So-Won; Yang, Yang; Kim, Kwang-Ho; Kwon, Se-Hun

    2017-04-01

    Multilayered hard coatings with a CrN matrix and an Al2O3, TiO2, or nanolaminate-Al2O3/TiO2 sealing layer were designed by a hybrid deposition process combined with physical vapor deposition (PVD) and atomic layer deposition (ALD). The strategy was to utilize ALD thin films as pinhole-free barriers to seal the intrinsic defects to protect the CrN matrix. The influences of the different sealing layers added in the coatings on the microstructure, surface roughness, and corrosion behaviors were investigated. The results indicated that the sealing layer added by ALD significantly decreased the average grain size and improved the corrosion resistance of the CrN coatings. The insertion of the nanolaminate-Al2O3/TiO2 sealing layers resulted in a further increase in corrosion resistance, which was attributed to the synergistic effect of Al2O3 and TiO2, both acting as excellent passivation barriers to the diffusion of corrosive substances.

  20. Microstructural effects associated to CTE mismatch for enhancing the thermal shock resistance of refractories

    International Nuclear Information System (INIS)

    Huger, M; Tessier-Doyen, N; Michaud, P; Chotard, T; Ota, T

    2011-01-01

    This work is devoted to the study of thermomechanical properties of several industrial and model refractory materials in relation with the evolution of their microstructure during thermal treatments. The aim is, in particular, to highlight the role of thermal expansion mismatches existing between phases which can induce damage at local scale. The resulting network of microcracks is well known to improve thermal shock resistance of materials, since it usually involves a significant decrease in elastic properties. Moreover, this network of microcracks can strongly affect the thermal expansion at low temperature and the stress-strain behaviour in tension. Even if these two last aspects are not so much documented in the literature, they certainly also constitute key points for the improvement of the thermal shock resistance of refractory materials. Evolution of damage during thermal cycling has been monitored by a specific ultrasonic device at high temperature. Beyond its influence on Young's modulus, this damage also allows to decrease the thermal expansion and to improve the non-linear character of the stress-strain curves determined in tension. The large increase in strain to rupture, which results from this non-linearity, is of great interest for thermal shock application.

  1. Curcumin Encapsulated in Milk Exosomes Resists Human Digestion and Possesses Enhanced Intestinal Permeability in Vitro.

    Science.gov (United States)

    Vashisht, Monika; Rani, Payal; Onteru, Suneel Kumar; Singh, Dheer

    2017-11-01

    Exosomes, the extracellular secretary nano-vesicles, act as carriers of biomolecules to the target cells. They exhibit several attributes of an efficient drug delivery system. Curcumin, despite having numerous bioactive and therapeutic properties, has limited pharmaceutical use due to its poor water solubility, stability, and low systemic bioavailability. Hence, this study aims to enhance the therapeutic potential of curcumin, a model hydrophobic drug, by its encapsulation into milk exosomes. In the present study, we investigated the stability of free curcumin and exosomal curcumin in PBS and in vitro digestive processes. Additionally, their uptake and trans-epithelial transport were studied on Caco-2 cells. Curcumin in milk exosomes had higher stability in PBS, sustained harsh digestive processes, and crossed the intestinal barrier than free curcumin. In conclusion, the encapsulation of curcumin into the exosomes enhances its stability, solubility, and bioavailability. Therefore, the present study demonstrated that milk exosomes act as stable oral drug delivery vehicles.

  2. Changes of renal blood flow after ESWL: Assessment by ASL MR imaging, contrast enhanced MR imaging, and renal resistive index

    Energy Technology Data Exchange (ETDEWEB)

    Abd Ellah, Mohamed, E-mail: dr_m_hamdy2006@hotmail.co [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Kremser, Christian, E-mail: christian.kremser@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pallwein, Leo, E-mail: leo.pallwein-prettner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Aigner, Friedrich, E-mail: friedrich.Aigner@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Schocke, Michael, E-mail: michael.schocke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Peschel, Reinhard, E-mail: reinhard.peschel@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Pedross, Florian, E-mail: florian.pedross@i-med.ac.a [Innsbruck Medical University, Medical Statistics Dept., Anich St. 35, 6020 Innsbruck (Austria); Pinggera, Germar-Michael, E-mail: germar.pinggera@uki.a [Innsbruck Medical University, Urology Dept., Anich St. 35, 6020 Innsbruck (Austria); Wolf, Christian, E-mail: christian.wolf@bkh-reutte.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Alsharkawy, Mostafa A.M., E-mail: drmostafamri@yahoo.co [Assiut University, Radiology Dept., Assiut (Egypt); Jaschke, Werner, E-mail: werner.jaschke@i-med.ac.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria); Frauscher, Ferdinand, E-mail: ferdinand.frauscher@uki.a [Innsbruck Medical University, Radiology Dept., Anich St. 35, 6020 Innsbruck (Austria)

    2010-10-15

    The annual incidence of stone formation is increased in the industrialised world. Extracorporeal shockwave lithotripsy is a non-invasive effective treatment of upper urinary tract stones. This study is aimed to evaluate changes of renal blood flow in patients undergoing extracorporeal shock wave lithotripsy (ESWL) by arterial spin labeling (ASL) MR imaging, contrast enhanced dynamic MR imaging, and renal resistive index (RI). Thirteen patients with nephrolithiasis were examined using MR imaging and Doppler ultrasound 12 h before and 12 h after ESWL. ASL sequence was done for both kidneys and followed by contrast enhanced MR imaging. In addition RI Doppler ultrasound measurements were performed. A significant increase in RI (p < 0.001) was found in both treated and untreated kidneys. ASL MR imaging also showed significant changes in both kidneys (p < 0.001). Contrast enhanced dynamic MR imaging did not show significant changes in the kidneys. ESWL causes changes in RI and ASL MR imaging, which seem to reflect changes in renal blood flow.

  3. SHORT-TERM STRESS ENHANCES CELLULAR IMMUNITY AND INCREASES EARLY RESISTANCE TO SQUAMOUS CELL CARCINOMA

    OpenAIRE

    Dhabhar, Firdaus S.; Saul, Alison N.; Daugherty, Christine; Holmes, Tyson H.; Bouley, Donna M.; Oberyszyn, Tatiana M.

    2009-01-01

    In contrast to chronic/long-term stress that suppresses/dysregulates immune function, an acute/short-term fight-or-flight stress response experienced during immune activation can enhance innate and adaptive immunity. Moderate ultraviolet-B (UV) exposure provides a non-invasive system for studying the naturalistic emergence, progression and regression of squamous cell carcinoma (SCC). Because SCC is an immunoresponsive cancer, we hypothesized that short-term stress experienced before UV exposu...

  4. IS ENHANCED-ECCENTRIC RESISTANCE TRAINING SUPERIOR TO TRADITIONAL TRAINING FOR INCREASING ELBOW FLEXOR STRENGTH?

    Directory of Open Access Journals (Sweden)

    Thomas W. Kaminski

    2003-06-01

    Full Text Available Protocols for strengthening muscle are important for fitness, rehabilitation, and the prevention of myotendinous injuries. In trained individuals, the optimal method of increasing strength remains unclear. The purpose of this study was to compare the effects of a traditional method of strengthening with a method that allowed for enhanced-eccentric training, on changes in elbow flexor strength in trained subjects. Thirty-nine (8 male, 31 female trained subjects with normal elbow function participated in this study. Subjects were rank-ordered according to isometric force production and randomly assigned to one of three training groups: control (CONT, traditional concentric/eccentric (TRAD, and concentric/enhanced-eccentric (NEG. The training groups completed 24 training sessions. An evaluator blinded to training group performed all testing. Mixed model ANOVA techniques were used to determine if differences existed in concentric one repetition maximum strength, and isometric force production among groups. Changes in peak and average isokinetic force production were also compared. Type 1 error was maintained at 5%. While both groups improved concentric one repetition maximum (NEG = 15.5%, TRAD = 13.8% neither training group statistically differed from changes demonstrated by the CONT group. Nor did either training group show significant improvements in isometric or isokinetic force production over the CONT group. These results do not support the superiority of enhanced-eccentric training for increasing force production in trained subjects.

  5. Caffeine ingestion acutely enhances muscular strength and power but not muscular endurance in resistance-trained men.

    Science.gov (United States)

    Grgic, Jozo; Mikulic, Pavle

    2017-09-01

    The goal of this randomized, double-blind, cross-over study was to assess the acute effects of caffeine ingestion on muscular strength and power, muscular endurance, rate of perceived exertion (RPE), and pain perception (PP) in resistance-trained men. Seventeen volunteers (mean ± SD: age = 26 ± 6 years, stature = 182 ± 9 cm, body mass = 84 ± 9 kg, resistance training experience = 7 ± 3 years) consumed placebo or 6 mg kg -1 of anhydrous caffeine 1 h before testing. Muscular power was assessed with seated medicine ball throw and vertical jump exercises, muscular strength with one-repetition maximum (1RM) barbell back squat and bench press exercises, and muscular endurance with repetitions of back squat and bench press exercises (load corresponding to 60% of 1RM) to momentary muscular failure. RPE and PP were assessed immediately after the completion of the back squat and bench press exercises. Compared to placebo, caffeine intake enhanced 1RM back squat performance (+2.8%; effect size [ES] = 0.19; p = .016), which was accompanied by a reduced RPE (+7%; ES = 0.53; p = .037), and seated medicine ball throw performance (+4.3%, ES = 0.32; p = .009). Improvements in 1RM bench press were not noted although there were significant (p = .029) decreases in PP related to this exercise when participants ingested caffeine. The results point to an acute benefit of caffeine intake in enhancing lower-body strength, likely due to a decrease in RPE; upper-, but not lower-body power; and no effects on muscular endurance, in resistance-trained men. Individuals competing in events in which strength and power are important performance-related factors may consider taking 6 mg kg -1 of caffeine pre-training/competition for performance enhancement.

  6. Two-phase mixed media dielectric with macro dielectric beads for enhancing resistivity and breakdown strength

    Science.gov (United States)

    Falabella, Steven; Meyer, Glenn A; Tang, Vincent; Guethlein, Gary

    2014-06-10

    A two-phase mixed media insulator having a dielectric fluid filling the interstices between macro-sized dielectric beads packed into a confined volume, so that the packed dielectric beads inhibit electro-hydrodynamically driven current flows of the dielectric liquid and thereby increase the resistivity and breakdown strength of the two-phase insulator over the dielectric liquid alone. In addition, an electrical apparatus incorporates the two-phase mixed media insulator to insulate between electrical components of different electrical potentials. And a method of electrically insulating between electrical components of different electrical potentials fills a confined volume between the electrical components with the two-phase dielectric composite, so that the macro dielectric beads are packed in the confined volume and interstices formed between the macro dielectric beads are filled with the dielectric liquid.

  7. Heat enhancement of radiation resistivity of evaporated CsI, KI and KBr photocathodes

    CERN Document Server

    Tremsin, A S

    2000-01-01

    The photoemissive stability of as-deposited and heat-treated CsI, KI and KBr evaporated thin films under UV radiation is examined in this paper. After the deposition, some photocathodes were annealed for several hours at 90 deg. C in vacuum and their performance was then compared to the performance of non-heated samples. We observed that the post-evaporation thermal treatment not only increases the photoyield of CsI and KI photocathodes in the spectral range of 115-190 nm, but also reduces CsI, KI and KBr photocurrent degradation that occurs after UV irradiation. KBr evaporated layers appeared to be more radiation-resistant than CsI and KI layers. Post-deposition heat treatment did not result in any significant variation of KBr UV sensitivity.

  8. The enhanced callose deposition in barley with ml-o powdery mildew resistance genes

    DEFF Research Database (Denmark)

    Skou, Jens-Peder

    1985-01-01

    Carborundum treatment of barley leaves induced a callose deposition which was detected as diffuse blotches in the epidermal cells of susceptible barleys and as deeply stained tracks along the scratches in barleys with the ml-o powdery mildew resistance gene. Subsequent inoculation with powdery...... mildew resulted in appositions that enlarged inversely to their size in the respective varieties when inoculated without carborundum treatment. Aphids sucking the leaves resulted in rows of callose containing spots along the anticlinal cell walls. The spots were larger in the ml-o mutant than...... in the mother variety. Callose was deposited in connection with the pleiotropic necrotic spotting in barleys with the ml-o gene. Modification of the necrotic spotting by crossing the ml-o gene into other gene backgrounds did not result in any change in the size of appositions upon inoculation with powdery...

  9. Enhancing the Thermal Resistance of a Novel Acidobacteria-Derived Phytase by Engineering of Disulfide Bridges.

    Science.gov (United States)

    Tan, Hao; Miao, Renyun; Liu, Tianhai; Cao, Xuelian; Wu, Xiang; Xie, Liyuan; Huang, Zhongqian; Peng, Weihong; Gan, Bingcheng

    2016-10-28

    A novel phytase of Acidobacteria was identified from a soil metagenome, cloned, overexpressed, and purified. It has low sequence similarity (phytases. At the optimum pH (2.5), the phytase shows an activity level of 1,792 μmol/min/mg at physiological temperature (37°C) and could retain 92% residual activity after 30 min, indicating the phytase is acidophilic and acidostable. However the phytase shows poor stability at high temperatures. To improve its thermal resistance, the enzyme was redesigned using Disulfide by Design 2.0, introducing four additional disulfide bridges. The half-life time of the engineered phytase at 60°C and 80°C, respectively, is 3.0× and 2.8× longer than the wild-type, and its activity and acidostability are not significantly affected.

  10. Ethanol from lignocellulose - Fermentation inhibitors, detoxification and genetic engineering of Saccharomyces cerevisiae for enhanced resistance

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Simona

    2000-07-01

    Ethanol can be produced from lignocellulose by first hydrolysing the material to sugars, and then fermenting the hydrolysate with the yeast Saccharomyces cerevisiae. Hydrolysis using dilute sulphuric acid has advantages over other methods, however, compounds which inhibit fermentation are generated during this kind of hydrolysis. The inhibitory effect of aliphatic acids, furans, and phenolic compounds was investigated. The generation of inhibitors during hydrolysis was studied using Norway spruce as raw material. It was concluded that the decrease in the fermentability coincided with increasing harshness of the hydrolysis conditions. The decrease in fermentability was not correlated solely to the content of aliphatic acids or furan derivatives. To increase the fermentability, detoxification is often employed. Twelve detoxification methods were compared with respect to the chemical composition of the hydrolysate and the fermentability after treatment. The most efficient detoxification methods were anion-exchange at pH 10.0, overliming and enzymatic detoxification with the phenol-oxidase laccase. Detailed analyses of ion exchange revealed that anion exchange and unspecific hydrophobic interactions greatly contributed to the detoxification effect, while cation exchange did not. The comparison of detoxification methods also showed that phenolic compounds are very important fermentation inhibitors, as their selective removal with laccase had a major positive effect on the fermentability. Selected compounds; aliphatic acids, furans and phenolic compounds, were characterised with respect to their inhibitory effect on ethanolic fermentation by S. cerevisiae. When aliphatic acids or furans were compared, the inhibitory effects were found to be in the same range, but the phenolic compounds displayed widely different inhibitory effects. The possibility of genetically engineering S. cerevisiae to achieve increased inhibitor resistance was explored by heterologous expression of

  11. Enhanced performance of electrostatic precipitators through chemical modification of particle resistivity and cohesion

    Energy Technology Data Exchange (ETDEWEB)

    Durham, M.D.; Baldrey, K.E.; Bustard, C.J. [ADA Technologies, Inc., Englewood, CO (United States)

    1995-11-01

    Control of fine particles, including particulate air toxics, from utility boilers is required near-term by state and federal air regulations. Electrostatic precipitators (ESP) serve as the primary air pollution control device for the majority of coal-fired utility boilers in the Eastern and Midwestern united States. Cost-effective retrofit technologies for fine particle control, including flue gas conditioning, are needed for the large base of existing ESPs. Flue has conditioning is an attractive option because it requires minimal structural changes and lower capital costs. For flue gas conditioning to be effective for fine particle control, cohesive and particle agglomerating agents are needed to reduce reentrainment losses, since a large percentage of particulate emissions from well-performing ESPs are due to erosion, rapping, and non-rapping reentrainment. A related and somewhat ironic development is that emissions reductions of SO{sub 2} from utility boilers, as required by the Title IV acid rain program of the 1990 Clean Air Act amendments, has the potential to substantially increase particulate air toxics from existing ESPs. The switch to low-sulfur coals as an SO{sub 2} control strategy by many utilities has exacerbated ESP performance problems associated with high resistivity flyash. The use of flue gas conditioning has increased in the past several years to maintain adequate performance in ESPs which were not designed for high resistivity ash. However, commercially available flue gas conditioning systems, including NH{sub 3}/SO{sub 3} dual gas conditioning systems, have problems and inherent drawbacks which create a need for alternative conditioning agents. in particular, NH{sub 3}/SO{sub 3} systems can create odor and ash disposal problems due to ammonia outgassing. In addition, there are concerns over chemical handling safety and the potential for accidental releases.

  12. Fate of antibiotic resistance genes in mesophilic and thermophilic anaerobic digestion of chemically enhanced primary treatment (CEPT) sludge.

    Science.gov (United States)

    Jang, Hyun Min; Shin, Jingyeong; Choi, Sangki; Shin, Seung Gu; Park, Ki Young; Cho, Jinwoo; Kim, Young Mo

    2017-11-01

    Anaerobic digestion (AD) of chemically enhanced primary treatment (CEPT) sludge and non-CEPT (conventional sedimentation) sludge were comparatively operated under mesophilic and thermophilic conditions. The highest methane yield (692.46±0.46mL CH 4 /g VS removed in CEPT sludge) was observed in mesophilic AD of CEPT sludge. Meanwhile, thermophilic conditions were more favorable for the removal of total antibiotic resistance genes (ARGs). In this study, no measurable difference in the fates and removal of ARGs and class 1 integrin-integrase gene (intI1) was observed between treated non-CEPT and CEPT sludge. However, redundancy analysis indicated that shifts in bacterial community were primarily accountable for the variations in ARGs and intI1. Network analysis further revealed potential host bacteria for ARGs and intI1. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. The Arabidopsis mutant cev1 has constitutively active jasmonate and ethylene signal pathways and enhanced resistance to pathogens.

    Science.gov (United States)

    Ellis, C; Turner, J G

    2001-05-01

    Jasmonates (JAs) inhibit plant growth and induce plant defense responses. To define genes in the Arabidopsis JA signal pathway, we screened for mutants with constitutive expression of a luciferase reporter for the JA-responsive promoter from the vegetative storage protein gene VSP1. One mutant, named constitutive expression of VSP1 (cev1), produced plants that were smaller than wild type, had stunted roots with long root hairs, accumulated anthocyanin, had constitutive expression of the defense-related genes VSP1, VSP2, Thi2.1, PDF1.2, and CHI-B, and had enhanced resistance to powdery mildew diseases. Genetic evidence indicated that the cev1 phenotype required both COI1, an essential component of the JA signal pathway, and ETR1, which encodes the ethylene receptor. We conclude that cev1 stimulates both the JA and the ethylene signal pathways and that CEV1 regulates an early step in an Arabidopsis defense pathway.

  14. Biotin-Pt (IV)-indomethacin hybrid: A targeting anticancer prodrug providing enhanced cancer cellular uptake and reversing cisplatin resistance.

    Science.gov (United States)

    Hu, Weiwei; Fang, Lei; Hua, Wuyang; Gou, Shaohua

    2017-10-01

    A Pt(IV) prodrug (2) composed of cancer-targeting biotin and nonsteroidal anti-inflammatory drug indomethacin in the axial positions of the six-coordinated octahedral geometry derived from cisplatin was developed, which could be highly accumulated in cancer cells more than normal ones and activated by endogenous reducing molecules to release cisplatin and indomethacin moieties simultaneously to inhibit tumor progression synergistically. In vitro assays revealed that 2 exhibited significantly selective inhibition to the tested cancer cell lines and sensitivity to cisplatin resistant cancer cells. Moreover, 2 presented cyclooxygenases inhibition properties to reduce tumor-associated inflammation, reduced the invasiveness of the highly aggressive PC-3 cells, and disrupted capillary-like tube formation in EA.hy926 cells. In all, this study offers a new strategy to enhance sensitivity and reduce toxicity of cisplatin. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Multifunctional Nano-engineered Polymer Surfaces with Enhanced Mechanical Resistance and Superhydrophobicity

    Science.gov (United States)

    Hernández, Jaime J.; Monclús, Miguel A.; Navarro-Baena, Iván; Viela, Felipe; Molina-Aldareguia, Jon M.; Rodríguez, Isabel

    2017-03-01

    This paper presents a multifunctional polymer surface that provides superhydrophobicity and self-cleaning functions together with an enhancement in mechanical and electrical performance. These functionalities are produced by nanoimprinting high aspect ratio pillar arrays on polymeric matrix incorporating functional reinforcing elements. Two distinct matrix-filler systems are investigated specifically, Carbon Nanotube reinforced Polystyrene (CNT-PS) and Reduced Graphene Oxide reinforced Polyvinylidene Difluoride (RGO-PVDF). Mechanical characterization of the topographies by quantitative nanoindentation and nanoscratch tests are performed to evidence a considerable increase in stiffness, Young’s modulus and critical failure load with respect to the pristine polymers. The improvement on the mechanical properties is rationalized in terms of effective dispersion and penetration of the fillers into the imprinted structures as determined by confocal Raman and SEM studies. In addition, an increase in the degree of crystallization for the PVDF-RGO imprinted nanocomposite possibly accounts for the larger enhancement observed. Improvement of the mechanical ruggedness of functional textured surfaces with appropriate fillers will enable the implementation of multifunctional nanotextured materials in real applications.

  16. Chronic mitragynine (kratom) enhances punishment resistance in natural reward seeking and impairs place learning in mice.

    Science.gov (United States)

    Ismail, Nurul Iman W; Jayabalan, Nanthini; Mansor, Sharif Mahsufi; Müller, Christian P; Muzaimi, Mustapha

    2017-07-01

    Kratom (Mitragyna speciosa) is a widely abused herbal drug preparation in Southeast Asia. It is often consumed as a substitute for heroin, but imposing itself unknown harms and addictive burdens. Mitragynine is the major psychostimulant constituent of kratom that has recently been reported to induce morphine-like behavioural and cognitive effects in rodents. The effects of chronic consumption on non-drug related behaviours are still unclear. In the present study, we investigated the effects of chronic mitragynine treatment on spontaneous activity, reward-related behaviour and cognition in mice in an IntelliCage® system, and compared them with those of morphine and Δ-9-tetrahydrocannabinol (THC). We found that chronic mitragynine treatment significantly potentiated horizontal exploratory activity. It enhanced spontaneous sucrose preference and also its persistence when the preference had aversive consequences. Furthermore, mitragynine impaired place learning and its reversal. Thereby, mitragynine effects closely resembled that of morphine and THC sensitisation. These findings suggest that chronic mitragynine exposure enhances spontaneous locomotor activity and the preference for natural rewards, but impairs learning and memory. These findings confirm pleiotropic effects of mitragynine (kratom) on human lifestyle, but may also support the recognition of the drug's harm potential. © 2016 Society for the Study of Addiction.

  17. Overexpression of Three Glucosinolate Biosynthesis Genes in Brassica napus Identifies Enhanced Resistance to Sclerotinia sclerotiorum and Botrytis cinerea.

    Directory of Open Access Journals (Sweden)

    Yuanyuan Zhang

    Full Text Available Sclerotinia sclerotiorum and Botrytis cinerea are notorious plant pathogenic fungi with an extensive host range including Brassica crops. Glucosinolates (GSLs are an important group of secondary metabolites characteristic of the Brassicales order, whose degradation products are proving to be increasingly important in plant protection. Enhancing the defense effect of GSL and their associated degradation products is an attractive strategy to strengthen the resistance of plants by transgenic approaches. We generated the lines of Brassica napus with three biosynthesis genes involved in GSL metabolic pathway (BnMAM1, BnCYP83A1 and BnUGT74B1, respectively. We then measured the foliar GSLs of each transgenic lines and inoculated them with S. sclerotiorum and B. cinerea. Compared with the wild type control, over-expressing BnUGT74B1 in B. napus increased the aliphatic and indolic GSL levels by 1.7 and 1.5 folds in leaves respectively; while over-expressing BnMAM1 or BnCYP83A1 resulted in an approximate 1.5-fold higher only in the aliphatic GSL level in leaves. The results of plant inoculation demonstrated that BnUGT74B1-overexpressing lines showed less severe disease symptoms and tissue damage compared with the wild type control, but BnMAM1 or BnCYP83A1-overexpressing lines showed no significant difference in comparison to the controls. These results suggest that the resistance to S. sclerotiorum and B. cinerea in B. napus could be enhanced through tailoring the GSL profiles by transgenic approaches or molecular breeding, which provides useful information to assist plant breeders to design improved breeding strategies.

  18. The Wheat Bax Inhibitor-1 Protein Interacts with an Aquaporin TaPIP1 and Enhances Disease Resistance in Arabidopsis

    Directory of Open Access Journals (Sweden)

    Pan-Pan Lu

    2018-01-01

    Full Text Available Bax inhibitor-1 (BI-1 is an endoplasmic reticulum (ER-resident cell death suppressor evolutionarily conserved in eukaryotes. The ability of BI-1 to inhibit the biotic and abiotic stresses have been well-studied in Arabidopsis, while the functions of wheat BI-1 are largely unknown. In this study, the wheat BI-1 gene TaBI-1.1 was isolated by an RNA-seq analysis of Fusarium graminearum (Fg-treated wheat. TaBI-1.1 expression was induced by a salicylic acid (SA treatment and down-regulated by an abscisic acid (ABA treatment. Based on β-glucuronidase (GUS staining, TaBI-1.1 was expressed in mature leaves and roots but not in the hypocotyl or young leaves. Constitutive expression of TaBI-1.1 in Arabidopsis enhanced its resistance to Pseudomonas syringae pv. Tomato (Pst DC3000 infection and induced SA-related gene expression. Additionally, TaBI-1.1 transgenic Arabidopsis exhibited an alleviation of damage caused by high concentrations of SA and decreased the sensitivity to ABA. Consistent with the phenotype, the RNA-seq analysis of 35S::TaBI-1.1 and Col-0 plants showed that TaBI-1.1 was involved in biotic stresses. These results suggested that TaBI-1.1 positively regulates SA signals and plays important roles in the response to biotic stresses. In addition, TaBI-1.1 interacted with the aquaporin TaPIP1, and both them were localized to ER membrane. Furthermore, we demonstrated that TaPIP1 was up-regulated by SA treatment and TaPIP1 transgenic Arabidopsis enhanced the resistance to Pst DC3000 infection. Thus, the interaction between TaBI-1.1 and TaPIP1 on the ER membrane probably occurs in response to SA signals and defense response.

  19. Overexpression of VpPR10.1 by an efficient transformation method enhances downy mildew resistance in V. vinifera.

    Science.gov (United States)

    Su, Hang; Jiao, Yun-Tong; Wang, Fang-Fang; Liu, Yue-E; Niu, Wei-Li; Liu, Guo-Tian; Xu, Yan

    2018-05-01

    Putrescine and spermidine increase the transformation efficiency of Vitis vinifera L. cv. Thompson seedless. Accumulation of VpPR10.1 in transgenic V. vinifera Thompson seedless, likely increases its resistance to downy mildew. A more efficient method is described for facilitating Agrobacterium-mediated transformation of Vitis vinifera L. cv. Thompson Seedless somatic embryogenesis using polyamines (PAs). The efficacies of putrescine, spermidine and spermine are identified at a range of concentrations (10 µM, 100 µM and 1 mM) added to the culture medium during somatic embryo growth. Putrescine (PUT) and spermidine (SPD) promote the recovery of proembryonic masses (PEM) and the development of somatic embryos (SE) after co-cultivation. Judging from the importance of the time-frame in genetic transformation, PAs added at the co-cultivation stage have a stronger effect than delayed selection treatments, which are superior to antibiotic treatments in the selection stage. Best embryogenic responses are with 1 mM PUT and 100 µM SPD added to the co-culture medium. Using the above method, a pathogenesis-related gene (VpPR10.1) from Chinese wild Vitis pseudoreticulata was transferred into Thompson Seedless for functional evaluation. The transgenic line, confirmed by western blot analysis, was inoculated with Plasmopara viticola to test for downy mildew resistance. Based on observed restrictions of hyphal growth and increases in H 2 O 2 accumulation in the transgenic plants, the accumulation of VpPR10.1 likely enhanced the transgenic plants resistance to downy mildew.

  20. Enhancement of non-specific immune response, resistance and growth of (Litopenaeus vannamei by oral administration of nucleotide

    Directory of Open Access Journals (Sweden)

    Henky Manoppo

    2011-01-01

    Full Text Available This research evaluated the nonspecific immune responsse, resistance, and growth of Litopenaeus vannamei fed nucleotide diet. Shrimp juveniles (mean weight 5.39±0.56 g were reared in two groups of glass aquaria, each with three replications. Shrimps in group one and group two were fed nucleotide diet and basal diet each for four weeks. Total haemocyte count (THC and PO activity were evaluated at the end of feeding while growth was measured at two weeks interval. At the end of feeding trial, the shrimps were intramuscularly injected with Vibrio harveyi 0.1x106 cfu.shrimp-1. THC of shrimp fed nucleotide diet significantly increased (P-1 diet showed positive effect on the enhancement of nonspecific immune responsse, resistance, and growth of L. vannamei.  Key words: Litopenaeus vannamei, nucleotide, THC, PO activity, resistance   ABSTRAK Penelitian bertujuan untuk mengevaluasi respons imun non-spesifik dan resistensi udang vaname (Litopenaeus vannamei yang diberi pakan nukleotida.  Juvenil (5,39±0,56 g dipelihara dalam dua kelompok akuarium kaca masing-masing dengan 3 ulangan.  Udang dalam dalam kelompok pertama diberi pakan nukleotida sedangkan udang dalam kelompok kedua diberi pakan standar selama 4 minggu. Total haemocyte count (THC dan aktivitas phenoloxidase (PO diukur pada akhir pemberian pakan sedangkan pertumbuhan udang diukur setiap dua minggu. Pada akhir periode pemberian pakan perlakuan, udang diuji tantang secara injeksi intramuskular dengan bakteri Vibrio harveyi 0,1x106 cfu.udang-1. THC udang yang diberi pakan nukleotida meningkat secara signifikan (P-1 pakan selama 4 minggu memberi pengaruh positif terhadap peningkatan respons imun non-spesifik, resistensi dan pertumbuhan udang vaname. Kata kunci: Litopenaeus vannamei, nukleotida, THC, aktivitas PO, resistensi

  1. Further studies on O2-resistant photosynthesis and photorespiration in a tobacco mutant with enhanced catalase activity

    International Nuclear Information System (INIS)

    Zelitch, I.

    1990-01-01

    The increase in net photosynthesis in M 4 progeny of an O 2 -resistant tobacco (Nicotiana tabacum) mutant relative to wild-type plants at 21 and 42% O 2 has been confirmed and further investigated. Self-pollination of an M 3 mutant produced M 4 progeny segregating high catalase phenotypes (average 40% greater than wild type) at a frequency of about 60%. The high catalase phenotype cosegregated precisely with O 2 -resistant photosynthesis. About 25% of the F 1 progeny of reciprocal crosses between the same M 3 mutant and wild type had high catalase activity, whether the mutant was used as the maternal or paternal parent, indicating nuclear inheritance. In high-catalase mutants the activity of NADH-hydroxypyruvate reductase, another peroxisomal enzyme, was the same as wild type. The mutants released 15% less photorespiratory CO 2 as a percent of net photosynthesis in CO 2 -free 21% O 2 and 36% less in CO 2 -free 42% O 2 compared with wild type. The mutant leaf tissue also released less 14 CO 2 per [1- 14 C]glycolate metabolized than wild type in normal air, consistent with less photorespiration in the mutant. The O 2 -resistant photosynthesis appears to be caused by a decrease in photorespiration especially under conditions of high O 2 where the stoichiometry of CO 2 release per glycolate metabolized is expected to be enhanced. The higher catalase activity in the mutant may decrease the nonenzymatic peroxidation of keto-acids such as hydroxypyruvate and glyoxylate by photorespiratory H 2 O 2

  2. Ectopic expression of a horseradish peroxidase enhances growth rate and increases oxidative stress resistance in hybrid aspen.

    Science.gov (United States)

    Kawaoka, Akiyoshi; Matsunaga, Etsuko; Endo, Saori; Kondo, Shinkichi; Yoshida, Kazuya; Shinmyo, Atsuhiko; Ebinuma, Hiroyasu

    2003-07-01

    We previously demonstrated that overexpression of the horseradish (Armoracia rusticana) peroxidase prxC1a gene stimulated the growth rate of tobacco (Nicotiana tabacum) plants. Here, the cauliflower mosaic virus 35S::prxC1a construct was introduced into hybrid aspen (Populus sieboldii x Populus grandidentata). The growth rate of these transformed hybrid aspen plants was substantially increased under greenhouse conditions. The average stem length of transformed plants was 25% greater than that of control plants. There was no other obvious phenotypic difference between the transformed and control plants. Fast-growing transformed hybrid aspen showed high levels of expression of prxC1a and had elevated peroxidase activities toward guaiacol and ascorbate. However, there was no increase of the endogenous class I ascorbate peroxidase activities in the transformed plants by separate assay and activity staining of native polyacrylamide gel electrophoresis. Furthermore, calli derived from the transformed hybrid aspen grew faster than those from control plants and were resistant to the oxidative stress imposed by hydrogen peroxide. Therefore, enhanced peroxidase activity affects plant growth rate and oxidative stress resistance.

  3. Plasmon Enhancement of Photoinduced Resistivity Changes in Bi1-xCaxMnO3 Thin Films

    Science.gov (United States)

    Smolyaninova, Vera; Talanova, E.; Kolagani, Rajeswari; Yong, G.; Kennedy, R.; Steger, M.; Wall, K.

    2007-03-01

    Doped rare-earth manganese oxides (manganites) exhibit a wide variety of physical phenomena due to complex interplay of electronic, magnetic, orbital, and structural degrees of freedom and their sensitivity to external fields. A photoinduced insulator to conductor transition in charge-ordered manganites is especially interesting from the point of view of creating photonic devices. Thin films of Bi0.4Ca0.6MnO3 exhibit large photoinduced resistivity changes associated with melting of the charge ordering by visible light [1]. We have found a considerable increase of the photoinduced resistivity changes in the Bi0.4Ca0.6MnO3 thin film after depositing metal nanoparticles on the surface. This increase can be explained by enhancement of local electromagnetic field in the vicinity of the gold nanoparticle due to the plasmon resonance. The changes in lifetime of the photoinduced state will be reported, and the possible origin of these effects will be discussed. [1] V. N. Smolyaninova at al., Appl. Phys. Lett. 86, 071922 (2005).

  4. Electrostatic Assembly Preparation of High-Toughness Zirconium Diboride-Based Ceramic Composites with Enhanced Thermal Shock Resistance Performance.

    Science.gov (United States)

    Zhang, Baoxi; Zhang, Xinghong; Hong, Changqing; Qiu, Yunfeng; Zhang, Jia; Han, Jiecai; Hu, PingAn

    2016-05-11

    The central problem of using ceramic as a structural material is its brittleness, which associated with rigid covalent or ionic bonds. Whiskers or fibers of strong ceramics such as silicon carbide (SiC) or silicon nitride (Si3N4) are widely embedded in a ceramic matrix to improve the strength and toughness. The incorporation of these insulating fillers can impede the thermal flow in ceramic matrix, thus decrease its thermal shock resistance that is required in some practical applications. Here we demonstrate that the toughness and thermal shock resistance of zirconium diboride (ZrB2)/SiC composites can be improved simultaneously by introducing graphene into composites via electrostatic assembly and subsequent sintering treatment. The incorporated graphene creates weak interfaces of grain boundaries (GBs) and optimal thermal conductance paths inside composites. In comparison to pristine ZrB2-SiC composites, the toughness of (2.0%) ZrB2-SiC/graphene composites exhibited a 61% increasing (from 4.3 to 6.93 MPa·m(1/2)) after spark plasma sintering (SPS); the retained strength after thermal shock increased as high as 74.8% at 400 °C and 304.4% at 500 °C. Present work presents an important guideline for producing high-toughness ceramic-based composites with enhanced thermal shock properties.

  5. Oreochromis mossambicus diet supplementation with Psidium guajava leaf extracts enhance growth, immune, antioxidant response and resistance to Aeromonas hydrophila.

    Science.gov (United States)

    Gobi, Narayanan; Ramya, Chinnu; Vaseeharan, Baskaralingam; Malaikozhundan, Balasubramanian; Vijayakumar, Sekar; Murugan, Kadarkarai; Benelli, Giovanni

    2016-11-01

    In this research, we focused on the efficacy of aqueous and ethanol leaf extracts of Psidium guajava L. (guava) based experimental diets on the growth, immune, antioxidant and disease resistance of tilapia, Oreochromis mossambicus following challenge with Aeromonas hydrophila. The experimental diets were prepared by mixing powdered (1, 5 and 10 mg/g) aqueous and ethanol extract of guava leaf with commercial diet. The growth (FW, FCR and SGR), non-specific cellular immune (myeloperoxidase activity, reactive oxygen activity and reactive nitrogen activity) humoral immune (complement activity, antiprotease, alkaline phosphatase activity and lysozyme activity) and antioxidant enzyme responses (SOD, GPX, and CAT) were examined after 30 days of post-feeding. A significant enhancement in the biochemical and immunological parameters of fish were observed fed with experimental diets compared to control. The dietary supplementation of P. guajava leaf extract powder for 30 days significantly reduced the mortality and increased the disease resistance of O. mossambicus following challenge with A. hydrophila at 50 μl (1 × 10 7  cells ml -1 ) compared to control after post-infection. The results suggest that the guava leaf extract could be used as a promising feed additive in aquaculture. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Transgenic plants producing the bacterial pheromone N-acyl-homoserine lactone exhibit enhanced resistance to the bacterial phytopathogen Erwinia carotovora.

    Science.gov (United States)

    Mäe, A; Montesano, M; Koiv, V; Palva, E T

    2001-09-01

    Bacterial pheromones, mainly different homoserine lactones, are central to a number of bacterial signaling processes, including those involved in plant pathogenicity. We previously demonstrated that N-oxoacyl-homoserine lactone (OHL) is essential for quorum sensing in the soft-rot phytopathogen Erwinia carotovora. In this pathogen, OHL controls the coordinate activation of genes encoding the main virulence determinants, extracellular plant cell wall degrading enzymes (PCWDEs), in a cell density-dependent manner. We suggest that E. carotovora employ quorum sensing to avoid the premature production of PCWDEs and subsequent activation of plant defense responses. To test whether modulating this sensory system would affect the outcome of a plant-pathogen interaction, we generated transgenic tobacco, producing OHL. This was accomplished by ectopic expression in tobacco of the E. carotovora gene expI, which is responsible for OHL biosynthesis. We show that expI-positive transgenic tobacco lines produced the active pheromone and partially complemented the avirulent phenotype of expI mutants. The OHL-producing tobacco lines exhibited enhanced resistance to infection by wild-type E. carotovora. The results were confirmed by exogenous addition of OHL to wild-type plants, which also resulted in increased resistance to E. carotovora.

  7. Hyaluronan-induced masking of ErbB2 and CD44-enhanced trastuzumab internalisation in trastuzumab resistant breast cancer.

    Science.gov (United States)

    Pályi-Krekk, Zsuzsanna; Barok, Márk; Isola, Jorma; Tammi, Markku; Szöllosi, János; Nagy, Peter

    2007-11-01

    Although trastuzumab, a recombinant humanised anti-ErbB2 antibody, is widely used in the treatment of breast cancer, neither its mechanism of action, nor the factors leading to resistance are fully understood. We have previously shown that antibody-dependent cellular cytotoxicity is pivotal in the in vivo effect of trastuzumab against JIMT-1, a cell line showing in vitro resistance to the antibody, and suggested that masking of the trastuzumab-binding epitope by MUC-4, a cell surface mucin, took place. Here, we further explored the role of masking of ErbB2 in connection with CD44 expression and synthesis of its ligand, hyaluronan. We show that high expression of CD44 observed in JIMT-1 cells correlates with ErbB2 downregulation in vivo, while siRNA-mediated inhibition of CD44 expression leads to decreased rate of trastuzumab internalisation and low cell proliferation in vitro. An inhibitor of hyaluronan synthesis, 4-methylumbelliferon (4-MU) significantly reduced the hyaluronan level of JIMT-1 cells both in vivo and in vitro leading to enhanced binding of trastuzumab to ErbB2 and increased ErbB2 down-regulation. Furthermore, the inhibitory effect of trastuzumab on the growth of JIMT-1 xenografts was significantly increased by 4-MU treatment. Our results point to the importance of the CD44-hyaluronan pathway in the escape of tumour cells from receptor-oriented therapy.

  8. Overexpression of HvIcy6 in Barley Enhances Resistance against Tetranychus urticae and Entails Partial Transcriptomic Reprogramming

    Directory of Open Access Journals (Sweden)

    M. Estrella Santamaria

    2018-03-01

    Full Text Available Cystatins have been largely used for pest control against phytophagous species. However, cystatins have not been commonly overexpressed in its cognate plant species to test their pesticide capacity. Since the inhibitory role of barley HvCPI-6 cystatin against the phytophagous mite Tetranychus urticae has been previously demonstrated, the purpose of our study was to determine if barley transgenic lines overexpressing its own HvIcy6 gene were more resistant against this phytophagous infestation. Besides, a transcriptomic analysis was done to find differential expressed genes among wild-type and transformed barley plants. Barley plants overexpressing HvIcy6 cystatin gene remained less susceptible to T. urticae attack when compared to wild-type plants, with a significant lesser foliar damaged area and a lower presence of the mite. Transcriptomic analysis revealed a certain reprogramming of cellular metabolism and a lower expression of several genes related to photosynthetic activity. Therefore, although caution should be taken to discard potential deleterious pleiotropic effects, cystatins may be used as transgenes with impact on agricultural crops by conferring enhanced levels of resistance to phytophagous pests.

  9. [Molecular mechanism of cisplatin to enhance the ability of TRAIL in reversing multidrug resistance in gastric cancer cells].

    Science.gov (United States)

    Zhu, Xingchao; Zhang, Kaiguang; Wang, Qiaomin; Chen, Si; Gou, Yawen; Cui, Yufang; Li, Qin

    2015-06-01

    To study the molecular mechanism of cisplatin to enhance the ability of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) in reversing multidrug resistance in vincristine-resistant human gastric cancer SGC7901/VCR cells. MTT assay was used to measure the 50% inhibiting concentration (IC₅₀) and cell survival in SGC7901 and SGC7901/VCR cells after different treatments. SGC7901/VCR cells were treated with different concentrations of DDP, different concentrations of TRAIL alone or in combination, and then the mRNA and protein levels of several genes were determined by RT-PCR, RT-qPCR and Western-blot analysis. After targeted silencing with specific siRNA and transfection of recombinant plasmid c-myc into the SGC7901/VCR cells, the mRNA and protein levels of DR4, DR5 and c-myc were determined by RT-PCR and Western-blot analysis. After combined treatment with TRAIL and DDP of the SGC7901/VCR cells, the IC₅₀ of VCR, DDP, ADM, and 5-Fu treatment was significantly decreased compared with the control group or TRAIL-treated group (P mechanism of DDP-induced sensitization of TRAIL to reverse the multidrug resistancein SGC7901/VCR cells.

  10. Topological design of all-ceramic dental bridges for enhancing fracture resistance.

    Science.gov (United States)

    Zhang, Zhongpu; Chen, Junning; Li, Eric; Li, Wei; Swain, Michael; Li, Qing

    2016-06-01

    Layered all-ceramic systems have been increasingly adopted in major dental prostheses. However, ceramics are inherently brittle, and they often subject to premature failure under high occlusion forces especially in the posterior region. This study aimed to develop mechanically sound novel topological designs for all-ceramic dental bridges by minimizing the fracture incidence under given loading conditions. A bi-directional evolutionary structural optimization (BESO) technique is implemented within the extended finite element method (XFEM) framework. Extended finite element method allows modeling crack initiation and propagation inside all-ceramic restoration systems. Following this, BESO searches the optimum distribution of two different ceramic materials, namely porcelain and zirconia, for minimizing fracture incidence. A performance index, as per a ratio of peak tensile stress to material strength, is used as a design objective. In this study, the novel XFEM based BESO topology optimization significantly improved structural strength by minimizing performance index for suppressing fracture incidence in the structures. As expected, the fracture resistance and factor of safety of fixed partial dentures structure increased upon redistributing zirconia and porcelain in the optimal topological configuration. Dental CAD/CAM systems and the emerging 3D printing technology were commercially available to facilitate implementation of such a computational design, exhibiting considerable potential for clinical application in the future. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  11. [Enhanced Resistance of Pea Plants to Oxidative: Stress Caused by Paraquat during Colonization by Aerobic Methylobacteria].

    Science.gov (United States)

    Agafonova, N V; Doronina, N Y; Trotsenko, Yu A

    2016-01-01

    The influence of colonization of the pea (Pisum sativum L.) by aerobic methylobacteria of five different species (Methylophilus flavus Ship, Methylobacterium extorquens G10, Methylobacillus arboreus Iva, Methylopila musalis MUSA, Methylopila turkiensis Sidel) on plant resistance to paraquat-induced stresses has been studied. The normal conditions of pea colonization by methylobacteria were characterized by a decrease in the activity of antioxidant enzymes (superoxide dismutase, catalase, and peroxidases) and in the concentrations of endogenous H2O2, proline, and malonic dialdehyde, which is a product of lipid peroxidation and indicator of damage to plant cell membranes, and an increase in the activity of the photosynthetic apparatus (the content of chlorophylls a, b and carotenoids). In the presence of paraquat, the colonized plants had higher activities of antioxidant enzymes, stable photosynthetic indices, and a less intensive accumulation of the products of lipid peroxidation as compared to noncolonized plants. Thus, colonization by methylobacteria considerably increased the adaptive protection of pea plants to the paraquat-induced oxidative stress.

  12. Female scent signals enhance the resistance of male mice to influenza.

    Directory of Open Access Journals (Sweden)

    Ekaterina A Litvinova

    Full Text Available BACKGROUND: The scent from receptive female mice functions as a signal, which stimulates male mice to search for potential mating partners. This searching behavior is coupled with infection risk due to sniffing both scent marks as well as nasal and anogenital areas of females, which harbor bacteria and viruses. Consideration of host evolution under unavoidable parasitic pressures, including helminthes, bacteria, viruses, etc., predicts adaptations that help protect hosts against the parasites associated with mating. METHODS AND FINDINGS: We propose that the perception of female signals by BALB/c male mice leads to adaptive redistribution of the immune defense directed to protection against respiratory infection risks. Our results demonstrate migration of macrophages and neutrophils to the upper airways upon exposure to female odor stimuli, which results in an increased resistance of the males to experimental influenza virus infection. This moderate leukocyte intervention had no negative effect on the aerobic performance in male mice. CONCLUSIONS: Our data provide the first demonstration of the adaptive immunological response to female odor stimuli through induction of nonspecific immune responses in the upper respiratory tract.

  13. Expression of Pinellia pedatisecta Lectin Gene in Transgenic Wheat Enhances Resistance to Wheat Aphids

    Directory of Open Access Journals (Sweden)

    Xiaoliang Duan

    2018-03-01

    Full Text Available Wheat aphids are major pests during the seed filling stage of wheat. Plant lectins are toxic to sap-sucking pests such as wheat aphids. In this study, Pinellia pedatisecta agglutinin (ppa, a gene encoding mannose binding lectin, was cloned, and it shared 92.69% nucleotide similarity and 94% amino acid similarity with Pinellia ternata agglutinin (pta. The ppa gene, driven by the constitutive and phloem-specific ribulose bisphosphate carboxylase small subunit gene (rbcs promoter in pBAC-rbcs-ppa expression vector, was transferred into the wheat cultivar Baofeng104 (BF104 by particle bombardment transformation. Fifty-four T0 transgenic plants were generated. The inheritance and expression of the ppa gene were confirmed by PCR and RT-PCR analysis respectively, and seven homozygous transgenic lines were obtained. An aphid bioassay on detached leaf segments revealed that seven ppa transgenic wheat lines had lower aphid growth rates and higher inhibition rates than BF104. Furthermore, two-year aphid bioassays in isolated fields showed that aphid numbers per tiller of transgenic lines were significantly decreased, compared with wild type BF104. Therefore, ppa could be a strong biotechnological candidate to produce aphid-resistant wheat.

  14. Field enhanced charge carrier reconfiguration in electronic and ionic coupled dynamic polymer resistive memory

    International Nuclear Information System (INIS)

    Zhao Junhui; Thomson, Douglas J; Freund, Michael S; Pilapil, Matt; Pillai, Rajesh G; Aminur Rahman, G M

    2010-01-01

    Dynamic resistive memory devices based on a conjugated polymer composite (PPy 0 DBS - Li + (PPy: polypyrrole; DBS - : dodecylbenzenesulfonate)), with field-driven ion migration, have been demonstrated. In this work the dynamics of these systems has been investigated and it has been concluded that increasing the applied field can dramatically increase the rate at which information can be 'written' into these devices. A conductance model using space charge limited current coupled with an electric field induced ion reconfiguration has been successfully utilized to interpret the experimentally observed transient conducting behaviors. The memory devices use the rising and falling transient current states for the storage of digital states. The magnitude of these transient currents is controlled by the magnitude and width of the write/read pulse. For the 500 nm length devices used in this work an increase in 'write' potential from 2.5 to 5.5 V decreased the time required to create a transient conductance state that can be converted into the digital signal by 50 times. This work suggests that the scaling of these devices will be favorable and that 'write' times for the conjugated polymer composite memory devices will decrease rapidly as ion driving fields increase with decreasing device size.

  15. A Resistive Boundary Condition Enhanced DGTD Scheme for the Transient Analysis of Graphene

    KAUST Repository

    Li, Ping

    2015-04-24

    In this paper, the electromagnetic (EM) features of graphene are characterized by a discontinuous Galerkin timedomain (DGTD) algorithm with a resistive boundary condition (RBC). The atomically thick graphene is equivalently modeled using a RBC by regarding the graphene as an infinitesimally thin conductive sheet. To incorporate RBC into the DGTD analysis, the surface conductivity of the graphene composed of contributions from both intraband and interband terms is firstly approximated by rational basis functions using the fastrelaxation vector-fitting (FRVF) method in the Laplace-domain. Next, through the inverse Laplace transform, the corresponding time-domain matrix equations in integral can be obtained. Finally, these matrix equations are solved by time-domain finite integral technique (FIT). For elements not touching the graphene sheet, however, the well-known Runge-Kutta (RK) method is employed to solve the two first-order time-derivative Maxwell’s equations. The application of the surface boundary condition significantly alleviates the memory consuming and the limitation of time step size required by Courant-Friedrichs-Lewy (CFL) condition. To validate the proposed algorithm, various numerical examples are presented and compared with available references.

  16. A Resistive Boundary Condition Enhanced DGTD Scheme for the Transient Analysis of Graphene

    KAUST Repository

    Li, Ping; Jiang, Li; Bagci, Hakan

    2015-01-01

    In this paper, the electromagnetic (EM) features of graphene are characterized by a discontinuous Galerkin timedomain (DGTD) algorithm with a resistive boundary condition (RBC). The atomically thick graphene is equivalently modeled using a RBC by regarding the graphene as an infinitesimally thin conductive sheet. To incorporate RBC into the DGTD analysis, the surface conductivity of the graphene composed of contributions from both intraband and interband terms is firstly approximated by rational basis functions using the fastrelaxation vector-fitting (FRVF) method in the Laplace-domain. Next, through the inverse Laplace transform, the corresponding time-domain matrix equations in integral can be obtained. Finally, these matrix equations are solved by time-domain finite integral technique (FIT). For elements not touching the graphene sheet, however, the well-known Runge-Kutta (RK) method is employed to solve the two first-order time-derivative Maxwell’s equations. The application of the surface boundary condition significantly alleviates the memory consuming and the limitation of time step size required by Courant-Friedrichs-Lewy (CFL) condition. To validate the proposed algorithm, various numerical examples are presented and compared with available references.

  17. Untranslatable tospoviral NSs fragment coupled with L conserved region enhances transgenic resistance against the homologous virus and a serologically unrelated tospovirus.

    Science.gov (United States)

    Yazhisai, Uthaman; Rajagopalan, Prem Anand; Raja, Joseph A J; Chen, Tsung-Chi; Yeh, Shyi-Dong

    2015-08-01

    Tospoviruses cause severe damages to important crops worldwide. In this study, Nicotiana benthamiana transgenic lines carrying individual untranslatable constructs comprised of the conserved region of the L gene (denoted as L), the 5' half of NSs coding sequence (NSs) or the antisense fragment of whole N coding sequence (N) of Watermelon silver mottle virus (WSMoV), individually or in combination, were generated. A total of 15-17 transgenic N. benthamiana lines carrying individual transgenes were evaluated against WSMoV and the serologically unrelated Tomato spotted wilt virus (TSWV). Among lines carrying single or chimeric transgenes, the level of resistance ranged from susceptible to completely resistant against WSMoV. From the lines carrying individual transgenes and highly resistant to WSMoV (56-63% of lines assayed), 30% of the L lines (3/10 lines assayed) and 11% of NSs lines (1/9 lines assayed) were highly resistant against TSWV. The chimeric transgenes provided higher degrees of resistance against WSMoV (80-88%), and the NSs fragment showed an additive effect to enhance the resistance to TSWV. Particularly, the chimeric transgenes with the triple combination of fragments, namely L/NSs/N or HpL/NSs/N (a hairpin construct), provided a higher degree of resistance (both 50%, with 7/14 lines assayed) against TSWV. Our results indicate that the untranslatable NSs fragment is able to enhance the transgenic resistance conferred by the L conserved region. The better performance of L/NSs/N and HpL/NSs/N in transgenic N. benthamiana lines suggests their potential usefulness in generating high levels of enhanced transgenic resistance against serologically unrelated tospoviruses in agronomic crops.

  18. K70Q adds high-level tenofovir resistance to "Q151M complex" HIV reverse transcriptase through the enhanced discrimination mechanism.

    Directory of Open Access Journals (Sweden)

    Atsuko Hachiya

    2011-01-01

    Full Text Available HIV-1 carrying the "Q151M complex" reverse transcriptase (RT mutations (A62V/V75I/F77L/F116Y/Q151M, or Q151Mc is resistant to many FDA-approved nucleoside RT inhibitors (NRTIs, but has been considered susceptible to tenofovir disoproxil fumarate (TFV-DF or TDF. We have isolated from a TFV-DF-treated HIV patient a Q151Mc-containing clinical isolate with high phenotypic resistance to TFV-DF. Analysis of the genotypic and phenotypic testing over the course of this patient's therapy lead us to hypothesize that TFV-DF resistance emerged upon appearance of the previously unreported K70Q mutation in the Q151Mc background. Virological analysis showed that HIV with only K70Q was not significantly resistant to TFV-DF. However, addition of K70Q to the Q151Mc background significantly enhanced resistance to several approved NRTIs, and also resulted in high-level (10-fold resistance to TFV-DF. Biochemical experiments established that the increased resistance to tenofovir is not the result of enhanced excision, as K70Q/Q151Mc RT exhibited diminished, rather than enhanced ATP-based primer unblocking activity. Pre-steady state kinetic analysis of the recombinant enzymes demonstrated that addition of the K70Q mutation selectively decreases the binding of tenofovir-diphosphate (TFV-DP, resulting in reduced incorporation of TFV into the nascent DNA chain. Molecular dynamics simulations suggest that changes in the hydrogen bonding pattern in the polymerase active site of K70Q/Q151Mc RT may contribute to the observed changes in binding and incorporation of TFV-DP. The novel pattern of TFV-resistance may help adjust therapeutic strategies for NRTI-experienced patients with multi-drug resistant (MDR mutations.

  19. Nano-socketed nickel particles with enhanced coking resistance grown in situ by redox exsolution

    Science.gov (United States)

    Neagu, Dragos; Oh, Tae-Sik; Miller, David N.; Ménard, Hervé; Bukhari, Syed M.; Gamble, Stephen R.; Gorte, Raymond J.; Vohs, John M.; Irvine, John T. S.

    2015-09-01

    Metal particles supported on oxide surfaces are used as catalysts for a wide variety of processes in the chemical and energy conversion industries. For catalytic applications, metal particles are generally formed on an oxide support by physical or chemical deposition, or less commonly by exsolution from it. Although fundamentally different, both methods might be assumed to produce morphologically and functionally similar particles. Here we show that unlike nickel particles deposited on perovskite oxides, exsolved analogues are socketed into the parent perovskite, leading to enhanced stability and a significant decrease in the propensity for hydrocarbon coking, indicative of a stronger metal-oxide interface. In addition, we reveal key surface effects and defect interactions critical for future design of exsolution-based perovskite materials for catalytic and other functionalities. This study provides a new dimension for tailoring particle-substrate interactions in the context of increasing interest for emergent interfacial phenomena.

  20. Surfactant-free electrodeposition of reduced graphene oxide/copper composite coatings with enhanced wear resistance

    Science.gov (United States)

    Mai, Y. J.; Zhou, M. P.; Ling, H. J.; Chen, F. X.; Lian, W. Q.; Jie, X. H.

    2018-03-01

    How to uniformly disperse graphene sheets into the electrolyte is one of the main challenges to synthesize graphene enhanced nanocomposites by electrodeposition. A surfactant-free colloidal solution comprised of copper (II)-ethylene diamine tetra acetic acid ([CuIIEDTA]2-) complexes and graphene oxide (GO) sheets is proposed to electrodeposit reduced graphene oxide/copper (RGO/Cu) composite coatings. Anionic [CuIIEDTA]2- complexes stably coexist with negatively charged GO sheets due to the electrostatic repulsion between them, facilitating the electrochemical reduction and uniform dispersion of GO sheets into the copper matrix. The RGO/Cu composite coatings are well characterized by XRD, Raman, SEM and XPS. Their tribological behavior as a function of RGO content in composite coatings and normal loads are investigated. Also the chemical composition and topography of the wear tracks for the composite coatings are analyzed to deduce the lubricating and anti-wear mechanism of RGO/Cu composite coatings.

  1. Gene expression analysis of two extensively drug-resistant tuberculosis isolates show that two-component response systems enhance drug resistance.

    Science.gov (United States)

    Yu, Guohua; Cui, Zhenling; Sun, Xian; Peng, Jinfu; Jiang, Jun; Wu, Wei; Huang, Wenhua; Chu, Kaili; Zhang, Lu; Ge, Baoxue; Li, Yao

    2015-05-01

    Global analysis of expression profiles using DNA microarrays was performed between a reference strain H37Rv and two clinical extensively drug-resistant isolates in response to three anti-tuberculosis drug exposures (isoniazid, capreomycin, and rifampicin). A deep analysis was then conducted using a combination of genome sequences of the resistant isolates, resistance information, and related public microarray data. Certain known resistance-associated gene sets were significantly overrepresented in upregulated genes in the resistant isolates relative to that observed in H37Rv, which suggested a link between resistance and expression levels of particular genes. In addition, isoniazid and capreomycin response genes, but not rifampicin, either obtained from published works or our data, were highly consistent with the differentially expressed genes of resistant isolates compared to those of H37Rv, indicating a strong association between drug resistance of the isolates and genes differentially regulated by isoniazid and capreomycin exposures. Based on these results, 92 genes of the studied isolates were identified as candidate resistance genes, 10 of which are known resistance-related genes. Regulatory network analysis of candidate resistance genes using published networks and literature mining showed that three two-component regulatory systems and regulator CRP play significant roles in the resistance of the isolates by mediating the production of essential envelope components. Finally, drug sensitivity testing indicated strong correlations between expression levels of these regulatory genes and sensitivity to multiple anti-tuberculosis drugs in Mycobacterium tuberculosis. These findings may provide novel insights into the mechanism underlying the emergence and development of drug resistance in resistant tuberculosis isolates and useful clues for further studies on this issue. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. A mutation in a coproporphyrinogen III oxidase gene confers growth inhibition, enhanced powdery mildew resistance and powdery mildew-induced cell death in Arabidopsis.

    Science.gov (United States)

    Guo, Chuan-yu; Wu, Guang-heng; Xing, Jin; Li, Wen-qi; Tang, Ding-zhong; Cui, Bai-ming

    2013-05-01

    A gene encoding a coproporphyrinogen III oxidase mediates disease resistance in plants by the salicylic acid pathway. A number of genes that regulate powdery mildew resistance have been identified in Arabidopsis, such as ENHANCED DISEASE RESISTANCE 1 to 3 (EDR1 to 3). To further study the molecular interactions between the powdery mildew pathogen and Arabidopsis, we isolated and characterized a mutant that exhibited enhanced resistance to powdery mildew. The mutant also showed dramatic powdery mildew-induced cell death as well as growth defects and early senescence in the absence of pathogens. We identified the affected gene by map-based cloning and found that the gene encodes a coproporphyrinogen III oxidase, a key enzyme in the tetrapyrrole biosynthesis pathway, previously known as LESION INITIATION 2 (LIN2). Therefore, we designated the mutant lin2-2. Further studies revealed that the lin2-2 mutant also displayed enhanced resistance to Hyaloperonospora arabidopsidis (H.a.) Noco2. Genetic analysis showed that the lin2-2-mediated disease resistance and spontaneous cell death were dependent on PHYTOALEXIN DEFICIENT 4 (PAD4), SALICYLIC ACID INDUCTION-DEFICIENT 2 (SID2), and NONEXPRESSOR OF PATHOGENESIS-RELATED GENES 1 (NPR1), which are all involved in salicylic acid signaling. Furthermore, the relative expression levels of defense-related genes were induced after powdery mildew infection in the lin2-2 mutant. These data indicated that LIN2 plays an important role in cell death control and defense responses in plants.

  3. Expression of multiple resistance genes enhances tolerance to environmental stressors in transgenic poplar (Populus × euramericana 'Guariento'.

    Directory of Open Access Journals (Sweden)

    Xiaohua Su

    Full Text Available Commercial and non-commercial plants face a variety of environmental stressors that often cannot be controlled. In this study, transgenic hybrid poplar (Populus × euramericana 'Guariento' harboring five effector genes (vgb, SacB, JERF36, BtCry3A and OC-I were subjected to drought, salinity, waterlogging and insect stressors in greenhouse or laboratory conditions. Field trials were also conducted to investigate long-term effects of transgenic trees on insects and salt tolerance in the transformants. In greenhouse studies, two transgenic lines D5-20 and D5-21 showed improved growth, as evidenced by greater height and basal diameter increments and total biomass relative to the control plants after drought or salt stress treatments. The improved tolerance to drought and salt was primarily attributed to greater instantaneous water use efficiency (WUEi in the transgenic trees. The chlorophyll concentrations tended to be higher in the transgenic lines under drought or saline conditions. Transformed trees in drought conditions accumulated more fructan and proline and had increased Fv/Fm ratios (maximum quantum yield of photosystem II under waterlogging stress. Insect-feeding assays in the laboratory revealed a higher total mortality rate and lower exuviation index of leaf beetle [Plagiodera versicolora (Laicharting] larvae fed with D5-21 leaves, suggesting enhanced insect resistance in the transgenic poplar. In field trials, the dominance of targeted insects on 2-year-old D5-21 transgenic trees was substantially lower than that of the controls, indicating enhanced resistance to Coleoptera. The average height and DBH (diameter at breast height of 2.5-year-old transgenic trees growing in naturally saline soil were 3.80% and 4.12% greater than those of the control trees, but these increases were not significant. These results suggested that multiple stress-resistance properties in important crop tree species could be simultaneously improved, although

  4. Subtle genetic changes enhance virulence of methicillin resistant and sensitive Staphylococcus aureus

    Directory of Open Access Journals (Sweden)

    Hawes Alicia C

    2007-11-01

    Full Text Available Abstract Background Community acquired (CA methicillin-resistant Staphylococcus aureus (MRSA increasingly causes disease worldwide. USA300 has emerged as the predominant clone causing superficial and invasive infections in children and adults in the USA. Epidemiological studies suggest that USA300 is more virulent than other CA-MRSA. The genetic determinants that render virulence and dominance to USA300 remain unclear. Results We sequenced the genomes of two pediatric USA300 isolates: one CA-MRSA and one CA-methicillin susceptible (MSSA, isolated at Texas Children's Hospital in Houston. DNA sequencing was performed by Sanger dideoxy whole genome shotgun (WGS and 454 Life Sciences pyrosequencing strategies. The sequence of the USA300 MRSA strain was rigorously annotated. In USA300-MRSA 2658 chromosomal open reading frames were predicted and 3.1 and 27 kilobase (kb plasmids were identified. USA300-MSSA contained a 20 kb plasmid with some homology to the 27 kb plasmid found in USA300-MRSA. Two regions found in US300-MRSA were absent in USA300-MSSA. One of these carried the arginine deiminase operon that appears to have been acquired from S. epidermidis. The USA300 sequence was aligned with other sequenced S. aureus genomes and regions unique to USA300 MRSA were identified. Conclusion USA300-MRSA is highly similar to other MRSA strains based on whole genome alignments and gene content, indicating that the differences in pathogenesis are due to subtle changes rather than to large-scale acquisition of virulence factor genes. The USA300 Houston isolate differs from another sequenced USA300 strain isolate, derived from a patient in San Francisco, in plasmid content and a number of sequence polymorphisms. Such differences will provide new insights into the evolution of pathogens.

  5. Increased resistance during jump exercise does not enhance cortical bone formation.

    Science.gov (United States)

    Boudreaux, Ramon D; Swift, Joshua M; Gasier, Heath G; Wiggs, Michael P; Hogan, Harry A; Fluckey, James D; Bloomfield, Susan A

    2014-01-01

    This study sought to elucidate the effects of a low- and high-load jump resistance exercise (RE) training protocol on cortical bone of the tibia and femur mid-diaphyses. Sprague-Dawley rats (male, 6 months old) were randomly assigned to high-load RE (HRE; n = 16), low-load RE (LRE; n = 15), or cage control (CC; n = 11) groups. Animals in the HRE and LRE groups performed 15 sessions of jump RE for 5 wk. Load in the HRE group was progressively increased from 80 g added to a weighted vest (50 repetitions) to 410 g (16 repetitions). The LRE rats completed the same protocol as the HRE group (same number of repetitions), with only a 30-g vest applied. Low- and high-load jump RE resulted in 6%-11% higher cortical bone mineral content and cortical bone area compared with controls, as determined by in vivo peripheral quantitative computed tomography measurements. In the femur, however, only LRE demonstrated improvements in cortical volumetric bone mineral density (+11%) and cross-sectional moment of inertia (+20%) versus the CC group. The three-point bending to failure revealed a marked increase in tibial maximum force (25%-29%), stiffness (19%-22%), and energy to maximum force (35%-55%) and a reduction in elastic modulus (-11% to 14%) in both LRE and HRE compared with controls. Dynamic histomorphometry assessed at the tibia mid-diaphysis determined that both LRE and HRE resulted in 20%-30% higher periosteal mineralizing surface versus the CC group. Mineral apposition rate and bone formation rate were significantly greater in animals in the LRE group (27%, 39%) than those in the HRE group. These data demonstrate that jump training with minimal loading is equally, and sometimes more, effective at augmenting cortical bone integrity compared with overload training in skeletally mature rats.

  6. PPARγ1 phosphorylation enhances proliferation and drug resistance in human fibrosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Pang, Xiaojuan; Shu, Yuxin; Niu, Zhiyuan; Zheng, Wei; Wu, Haochen [State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Lu, Yan, E-mail: luyan@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Shen, Pingping, E-mail: ppshen@nju.edu.cn [State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing (China); Model Animal Research Center (MARC), Nanjing University, Nanjing (China)

    2014-03-10

    Post-translational regulation plays a critical role in the control of cell growth and proliferation. The phosphorylation of peroxisome proliferator-activated receptor γ (PPARγ) is the most important post-translational modification. The function of PPARγ phosphorylation has been studied extensively in the past. However, the relationship between phosphorylated PPARγ1 and tumors remains unclear. Here we investigated the role of PPARγ1 phosphorylation in human fibrosarcoma HT1080 cell line. Using the nonphosphorylation (Ser84 to alanine, S84A) and phosphorylation (Ser84 to aspartic acid, S84D) mutant of PPARγ1, the results suggested that phosphorylation attenuated PPARγ1 transcriptional activity. Meanwhile, we demonstrated that phosphorylated PPARγ1 promoted HT1080 cell proliferation and this effect was dependent on the regulation of cell cycle arrest. The mRNA levels of cyclin-dependent kinase inhibitor (CKI) p21{sup Waf1/Cip1} and p27{sup Kip1} descended in PPARγ1{sup S84D} stable HT1080 cell, whereas the expression of p18{sup INK4C} was not changed. Moreover, compared to the PPARγ1{sup S84A}, PPARγ1{sup S84D} up-regulated the expression levels of cyclin D1 and cyclin A. Finally, PPARγ1 phosphorylation reduced sensitivity to agonist rosiglitazone and increased resistance to anticancer drug 5-fluorouracil (5-FU) in HT1080 cell. Our findings establish PPARγ1 phosphorylation as a critical event in human fibrosarcoma growth. These findings raise the possibility that chemical compounds that prevent the phosphorylation of PPARγ1 could act as anticancer drugs. - Highlights: • Phosphorylation attenuates PPARγ1 transcriptional activity. • Phosphorylated PPARγ1 promotes HT1080 cells proliferation. • PPARγ1 phosphorylation regulates cell cycle by mediating expression of cell cycle regulators. • PPARγ1 phosphorylation reduces sensitivity to agonist and anticancer drug. • Our findings establish PPARγ1 phosphorylation as a critical event in HT1080

  7. Lipocalin 2 Enhances Migration and Resistance against Cisplatin in Endometrial Carcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Tsutomu Miyamoto

    Full Text Available Lipocalin 2 (LCN2 is a secretory protein that is involved in various physiological processes including iron transport. We previously identified LCN2 as an up-regulated gene in endometrial carcinoma, and found that the overexpression of LCN2 and its receptor, SLC22A17, was associated with a poor prognosis. However, the functions and mechanism of action of LCN2 currently remain unclear.The LCN2-overexpressing endometrial carcinoma cell lines, HHUA and RL95-2, and LCN2-low-expressing one, HEC1B, were used. The effects of LCN2 on cell migration, cell viability, and apoptosis under various stresses, including ultraviolet (UV irradiation and cisplatin treatment, were examined using the scratch wound healing assay, WST-1 assay, and Apostrand assay, respectively.LCN2-silencing using shRNA method significantly reduced the migration ability of cells (p<0.05. Cytotoxic stresses significantly decreased the viability of LCN2-silenced cells more than that of control cells. In contrast, LCN2 overexpression was significantly increased cisplatin resistance. These effects were canceled by the addition of the iron chelator, deferoxamine. After UV irradiation, the expression of phosphorylated Akt (pAkt was decreased in LCN2-silenced cells, and the PI3K inhibitor canceled the difference induced in UV sensitivity by LCN2. The cisplatin-induced expression of pAkt was not affected by LCN2; however, the expression of p53 and p21 was increased by LCN2-silencing.These results indicated that LCN2 was involved in the migration and survival of endometrial carcinoma cells under various stresses in an iron-dependent manner. The survival function of LCN2 may be exerted through the PI3K pathway and suppression of the p53-p21 pathway. These functions of LCN2 may increase the malignant potential of endometrial carcinoma cells.

  8. Pentiptycene-based polyurethane with enhanced mechanical properties and CO2-plasticization resistance for thin film gas separation membranes.

    Science.gov (United States)

    Pournaghshband Isfahani, Ali; Sadeghi, Morteza; Wakimoto, Kazuki; Shrestha, Binod Babu; Bagheri, Rouhollah; Sivaniah, Easan; Ghalei, Behnam

    2018-04-30

    Development of thin film composite (TFC) membranes offers an opportunity to achieve the permeability/selectivity requirements for optimum CO2 separation performance. However, the durability and performance of thin film gas separation membranes are mostly challenged by weak mechanical properties and high CO2 plasticization. Here, we designed new polyurethane (PU) structures with bulky aromatic chain extenders that afford preferred mechanical properties for ultra-thin film formation. An improvement of about 1500% in Young's modulus and 600% in hardness was observed for pentiptycene-based PUs compared to typical PU membranes. Single (CO2, H2, CH4, and N2) and mixed (CO2/N2 and CO2/CH4) gas permeability tests were performed on the PU membranes. The resulting TFC membranes showed a high CO2 permeance up to 1400 GPU (10-6 cm3(STP) cm-2s-1 cmHg-1) and the CO2/N2 and CO2/H2 selectivities of about 22 and 2.1, respectively. The enhanced mechanical properties of pentiptycene-based PUs results in high performance thin membranes with the similar selectivity of the bulk polymer. The thin film membranes prepared from pentiptycene-based PUs also showed a two-fold enhanced plasticization resistance compared to non-pentiptycene containing PU membranes.

  9. Feeding behaviour of generalist pests on Brassica juncea: implication for manipulation of glucosinolate biosynthesis pathway for enhanced resistance.

    Science.gov (United States)

    Kumar, Pawan; Augustine, Rehna; Singh, Amarjeet Kumar; Bisht, Naveen C

    2017-10-01

    Differential accumulation of plant defence metabolites has been suggested to have important ecological consequence in the context of plant-insect interactions. Feeding of generalist pests on Brassica juncea showed a distinct pattern with selective exclusion of leaf margins which are high in glucosinolates. Molecular basis of this differential accumulation of glucosinolates could be explained based on differential expression profile of BjuMYB28 homologues, the major biosynthetic regulators of aliphatic glucosinolates, as evident from quantitative real-time PCR and promoter:GUS fusion studies in allotetraploid B. juncea. Constitutive overexpression of selected BjuMYB28 homologues enhanced accumulation of aliphatic glucosinolates in B. juncea. Performance of two generalist pests, Helicoverpa armigera and Spodoptera litura larvae, on transgenic B. juncea plants were poor compared to wild-type plants in a no-choice experiment. Correlation coefficient analysis suggested that weight gain of H. armigera larvae was negatively correlated with gluconapin (GNA) and glucobrassicanapin (GBN), whereas that of S. litura larvae was negatively correlated with GNA, GBN and sinigrin (SIN). Our study explains the significance and possible molecular basis of differential distribution of glucosinolates in B. juncea leaves and shows the potential of overexpressing BjuMYB28 for enhanced resistance of Brassica crops against the tested generalist pests. © 2017 John Wiley & Sons Ltd.

  10. Lead-resistant strain KQBT-3 inoculants of Tricholoma lobayensis Heim that enhance remediation of lead-contaminated soil.

    Science.gov (United States)

    Li, Ying; Qin, Chui-Xin; Gao, Biyu; Hu, Yuanjia; Xu, Heng

    2015-01-01

    To enhance lead-detoxifying efficiency of Tricholoma lobayensis Heim, one lead-resistant strain KQBT-3 (Bacillus thuringiensis) was applied owing to its excellent ability to tolerate Pb. KQBT-3 domesticated in liquid medium with increasing lead concentrations could tolerate Pb(NO3)2 up to a concentration of 800 mg L(-1). Pot experiments showed that the KQBT-3 not only could promote the growth of T. lobayensis, but also could enhance its Pb accumulation ability under heavy metal stress. Biomass and accumulation of Pb increased 47.3% and 33.2%, respectively. In addition, after inoculation of KQBT-3, the significant decrease of malondialdehyde indicated KQBT-3 could alleviate lipid peroxidation in T. lobayensis. What is interesting is that superoxide dismutase and peroxidase activities in T. lobayensis inoculated with KQBT-3 were increased, and the maximum increasing rate was 121.71% and 117.29%, respectively. However, the catalase activity increased slightly. This revealed that inoculating KQBT-3 further induced oxidative response in T. lobayensis due to Pb accumulation. Therefore, the present work showed that KQBT-3 made a major contribution to promote growth and lead uptake of T. lobayensis and alleviate the oxidative stress. This kind of auxiliary effect on macrofungi can be developed into a novel bioremediation strategy.

  11. Transgenic tomato plants overexpressing tyramine N-hydroxycinnamoyltransferase exhibit elevated hydroxycinnamic acid amide levels and enhanced resistance to Pseudomonas syringae.

    Science.gov (United States)

    Campos, Laura; Lisón, Purificación; López-Gresa, María Pilar; Rodrigo, Ismael; Zacarés, Laura; Conejero, Vicente; Bellés, José María

    2014-10-01

    Hydroxycinnamic acid amides (HCAA) are secondary metabolites involved in plant development and defense that have been widely reported throughout the plant kingdom. These phenolics show antioxidant, antiviral, antibacterial, and antifungal activities. Hydroxycinnamoyl-CoA:tyramine N-hydroxycinnamoyl transferase (THT) is the key enzyme in HCAA synthesis and is induced in response to pathogen infection, wounding, or elicitor treatments, preceding HCAA accumulation. We have engineered transgenic tomato plants overexpressing tomato THT. These plants displayed an enhanced THT gene expression in leaves as compared with wild type (WT) plants. Consequently, leaves of THT-overexpressing plants showed a higher constitutive accumulation of the amide coumaroyltyramine (CT). Similar results were found in flowers and fruits. Moreover, feruloyltyramine (FT) also accumulated in these tissues, being present at higher levels in transgenic plants. Accumulation of CT, FT and octopamine, and noradrenaline HCAA in response to Pseudomonas syringae pv. tomato infection was higher in transgenic plants than in the WT plants. Transgenic plants showed an enhanced resistance to the bacterial infection. In addition, this HCAA accumulation was accompanied by an increase in salicylic acid levels and pathogenesis-related gene induction. Taken together, these results suggest that HCAA may play an important role in the defense of tomato plants against P. syringae infection.

  12. Is rheumatoid arthritis a consequence of natural selection for enhanced tuberculosis resistance?

    Science.gov (United States)

    Mobley, James L

    2004-01-01

    Although the bubonic plague or "Black Death" is notorious for the toll it took on the population of Europe in the middle ages, another epidemic, the "White Death" of tuberculosis is responsible for millions of deaths worldwide over the past 300 years. With one in four deaths due to tuberculosis in Western Europe and the United States in the 19th century, this disease undoubtedly acted as a powerful genetic selective force. The epidemiology of modern day rheumatoid arthritis (RA) is strikingly similar to the epidemiology of tuberculosis 100-200 years ago, suggesting the possibility that genetic factors that enhanced survival in tuberculosis epidemics are now influencing susceptibility to RA. Recent advances in the analysis of genetic polymorphisms associated with disease have identified several genes linked to RA susceptibility that encode proteins involved in the immune response to Mycobacterium tuberculosis infection, including TNF-alpha, NRAMP1, PARP-1, HLA-DRB1, and PADI4. These results suggest that rheumatoid arthritis, and possibly other autoimmune diseases, are modern day manifestations of the genetic selective pressure exerted by tuberculosis epidemics of the recent past.

  13. Enhanced proline synthesis may determine resistance to salt stress in tomato cultivars

    International Nuclear Information System (INIS)

    Ali, S.; Khan, N.U.

    2011-01-01

    The physiological and biochemical responses of tomato cultivars were studied at Khyber Pakhtunkhwa Agricultural University, Peshawar, Pakistan during 2005-2006 for salt tolerance. Tomato cultivars were Roma Rio Super, Roma V.F., Chinese 87-5, Rio Grand and Super Blocky and subjected to salt stress (75 mM NaCl). Fresh weight, dry weight, and ions sodium and potassium accumulation, Na/sup +/K sup +/ ratio and proline content were determined after imposing the tomato cultivars to NaCl salt for 80 days. Salt stress significantly decreased the fresh and dry weight in Roma Rio Super, Roma V.F, Chinese 87-5 and Rio Grand, however, in Super Blocky the fresh and dry weight were enhanced under stress conditions. Salinity stress increased sodium uptake from 191.828 to 436.170 mu mg/sup -1/ D wt while potassium accumulation decreased from 1033.12 to 926.80 mu mg/sup -1/ D wt resulting in higher Na/sup +/ ratio in stressed (0.48 g) as compared to unstressed control (0.19). The mean proline contents also increased from 28.95 to 40.96 mu M Proline g/sup -1/ F. wt with the maximum increase (57.378%) in Super Blocky followed by Rio Grand (49.325%). (author)

  14. Transcutaneous spinal direct current stimulation induces lasting fatigue resistance and enhances explosive vertical jump performance

    Science.gov (United States)

    Tate, Rothwelle J.; Conway, Bernard A.

    2017-01-01

    Transcutaneous spinal direct current stimulation (tsDCS) is a non-invasive neuromodulatory intervention that has been shown to modify excitability in spinal and supraspinal circuits in animals and humans. Our objective in this study was to explore the functional neuromodulatory potential of tsDCS by examining its immediate and lasting effects over the repeated performance of a whole body maximal exercise in healthy volunteers. Using a double-blind, randomized, crossover, sham-controlled design we investigated the effects of 15 min of anodal tsDCS on repeated vertical countermovement jump (VCJ) performance at 0, 20, 60, and 180 minutes post-stimulation. Measurements of peak and take-off velocity, vertical displacement, peak power and work done during countermovement and push-off VCJ phases were derived from changes in vertical ground reaction force (12 performance parameters) in 12 healthy participants. The magnitude and direction of change in VCJ performance from pre- to post-stimulation differed significantly between sham and active tsDCS for 7 of the 12 VCJ performance measures (P 0.05). Our original findings demonstrate that one single session of anodal tsDCS in healthy subjects can prevent fatigue and maintain or enhance different aspects of whole body explosive motor power over repeated sets of VCJs performed over a period of three hours. The observed effects are discussed in relation to alterations in central fatigue mechanisms, muscle contraction mode during jump execution and changes in spinal cord excitability. These findings have important implications for power endurance sport performance and for neuromotor rehabilitation. PMID:28379980

  15. Transcutaneous spinal direct current stimulation induces lasting fatigue resistance and enhances explosive vertical jump performance.

    Directory of Open Access Journals (Sweden)

    Helen R Berry

    Full Text Available Transcutaneous spinal direct current stimulation (tsDCS is a non-invasive neuromodulatory intervention that has been shown to modify excitability in spinal and supraspinal circuits in animals and humans. Our objective in this study was to explore the functional neuromodulatory potential of tsDCS by examining its immediate and lasting effects over the repeated performance of a whole body maximal exercise in healthy volunteers. Using a double-blind, randomized, crossover, sham-controlled design we investigated the effects of 15 min of anodal tsDCS on repeated vertical countermovement jump (VCJ performance at 0, 20, 60, and 180 minutes post-stimulation. Measurements of peak and take-off velocity, vertical displacement, peak power and work done during countermovement and push-off VCJ phases were derived from changes in vertical ground reaction force (12 performance parameters in 12 healthy participants. The magnitude and direction of change in VCJ performance from pre- to post-stimulation differed significantly between sham and active tsDCS for 7 of the 12 VCJ performance measures (P 0.05. Our original findings demonstrate that one single session of anodal tsDCS in healthy subjects can prevent fatigue and maintain or enhance different aspects of whole body explosive motor power over repeated sets of VCJs performed over a period of three hours. The observed effects are discussed in relation to alterations in central fatigue mechanisms, muscle contraction mode during jump execution and changes in spinal cord excitability. These findings have important implications for power endurance sport performance and for neuromotor rehabilitation.

  16. ICP27-dependent resistance of herpes simplex virus type 1 to leptomycin B is associated with enhanced nuclear localization of ICP4 and ICP0

    International Nuclear Information System (INIS)

    Lengyel, Joy; Strain, Anna K.; Perkins, Keith D.; Rice, Stephen A.

    2006-01-01

    It was previously shown that herpes simplex virus type 1 (HSV-1) is sensitive to leptomycin B (LMB), an inhibitor of nuclear export factor CRM1, and that a single methionine to threonine change at residue 50 (M50T) of viral immediate-early (IE) protein ICP27 can confer LMB resistance. In this work, we show that deletion of residues 21-63 from ICP27 can also confer LMB resistance. We further show that neither the M50T mutation nor the presence of LMB affects the nuclear shuttling activity of ICP27, suggesting that another function of ICP27 determines LMB resistance. A possible clue to this function emerged when it was discovered that LMB treatment of HSV-1-infected cells dramatically enhances the cytoplasmic accumulation of two other IE proteins, ICP0 and ICP4. This effect is completely dependent on ICP27 and is reversed in cells infected with LMB-resistant mutants. Moreover, LMB-resistant mutations in ICP27 enhance the nuclear localization of ICP0 and ICP4 even in the absence of LMB, and this effect can be discerned in transfected cells. Thus, the same amino (N)-terminal region of ICP27 that determines sensitivity to LMB also enhances ICP27's previously documented ability to promote the cytoplasmic accumulation of ICP4 and ICP0. We speculate that ICP27's effects on ICP4 and ICP0 may contribute to HSV-1 LMB sensitivity

  17. Postexercise blood flow restriction does not enhance muscle hypertrophy induced by multiple-set high-load resistance exercise.

    Science.gov (United States)

    Madarame, Haruhiko; Nakada, Satoshi; Ohta, Takahisa; Ishii, Naokata

    2018-05-01

    To test the applicability of postexercise blood flow restriction (PEBFR) in practical training programmes, we investigated whether PEBFR enhances muscle hypertrophy induced by multiple-set high-load resistance exercise (RE). Seven men completed an eight-week RE programme for knee extensor muscles. Employing a within-subject design, one leg was subjected to RE + PEBFR, whereas contralateral leg to RE only. On each exercise session, participants performed three sets of unilateral knee extension exercise at approximately 70% of their one-repetition maximum for RE leg first, and then performed three sets for RE + PEBFR leg. Immediately after completion of the third set, the proximal portion of the RE + PEBFR leg was compressed with an air-pressure cuff for 5 min at a pressure ranging from 100 to 150 mmHg. If participants could perform 10 repetitions for three sets in two consecutive exercise sessions, the work load was increased by 5% at the next exercise session. Muscle thickness and strength of knee extensor muscles were measured before and after the eight-week training period and after the subsequent eight-week detraining period. There was a main effect of time but no condition × time interaction or main effect of condition for muscle thickness and strength. Both muscle thickness and strength increased after the training period independent of the condition. This result suggests that PEBFR would not be an effective training method at least in an early phase of adaptation to high-load resistance exercise. © 2017 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

  18. Overexpression of miR529a confers enhanced resistance to oxidative stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Yue, Erkui; Liu, Zhen; Li, Chao; Li, Yu; Liu, Qiuxiang; Xu, Jian-Hong

    2017-07-01

    Overexpressing miR529a can enhance oxidative stress resistance by targeting OsSPL2 and OsSPL14 genes that can regulate the expression of their downstream SOD and POD related genes. MicroRNAs are involved in the regulation of plant developmental and physiological processes, and their expression can be altered when plants suffered environment stresses, including salt, oxidative, drought and Cadmium. The expression of microRNA529 (miR529) can be induced under oxidative stress. However, its biological function under abiotic stress responses is still unclear. In this study, miR529a was overexpressed to investigate the function of miR529a under oxidative stress in rice. Our results demonstrated that the expression of miR529a can be induced by exogenous H 2 O 2 , and overexpressing miR529a can increase plant tolerance to high level of H 2 O 2 , resulting in increased seed germination rate, root tip cell viability, reduced leaf rolling rate and chlorophyll retention. The expression of oxidative stress responsive genes and the activities of superoxide dismutase (SOD) and peroxidase (POD) were increased in miR529a overexpression plant, which could help to reduce redundant reactive oxygen species (ROS). Furthermore, only OsSPL2 and OsSPL14 were targeted by miR529a in rice seedlings, repressing their expression in miR529aOE plants could lead to strengthen plant tolerance to oxidation stress. Our study provided the evidence that overexpression of miR529a could strengthen oxidation resistance, and its target genes OsSPL2 and OsSPL14 were responsible for oxidative tolerance, implied the manipulation of miR529a and its target genes regulation on H 2 O 2 related response genes could improve oxidative stress tolerance in rice.

  19. KP4 to control Ustilago tritici in wheat: Enhanced greenhouse resistance to loose smut and changes in transcript abundance of pathogen related genes in infected KP4 plants.

    Science.gov (United States)

    Quijano, Carolina Diaz; Wichmann, Fabienne; Schlaich, Thomas; Fammartino, Alessandro; Huckauf, Jana; Schmidt, Kerstin; Unger, Christoph; Broer, Inge; Sautter, Christof

    2016-09-01

    Ustilago tritici causes loose smut, which is a seed-borne fungal disease of wheat, and responsible for yield losses up to 40%. Loose smut is a threat to seed production in developing countries where small scale farmers use their own harvest as seed material. The killer protein 4 (KP4) is a virally encoded toxin from Ustilago maydis and inhibits growth of susceptible races of fungi from the Ustilaginales. Enhanced resistance in KP4 wheat to stinking smut, which is caused by Tilletia caries, had been reported earlier. We show that KP4 in genetically engineered wheat increased resistance to loose smut up to 60% compared to the non-KP4 control under greenhouse conditions. This enhanced resistance is dose and race dependent. The overexpression of the transgene kp4 and its effect on fungal growth have indirect effects on the expression of endogenous pathogen defense genes.

  20. KP4 to control Ustilago tritici in wheat: Enhanced greenhouse resistance to loose smut and changes in transcript abundance of pathogen related genes in infected KP4 plants

    Directory of Open Access Journals (Sweden)

    Carolina Diaz Quijano

    2016-09-01

    Full Text Available Ustilago tritici causes loose smut, which is a seed-borne fungal disease of wheat, and responsible for yield losses up to 40%. Loose smut is a threat to seed production in developing countries where small scale farmers use their own harvest as seed material. The killer protein 4 (KP4 is a virally encoded toxin from Ustilago maydis and inhibits growth of susceptible races of fungi from the Ustilaginales. Enhanced resistance in KP4 wheat to stinking smut, which is caused by Tilletia caries, had been reported earlier. We show that KP4 in genetically engineered wheat increased resistance to loose smut up to 60% compared to the non-KP4 control under greenhouse conditions. This enhanced resistance is dose and race dependent. The overexpression of the transgene kp4 and its effect on fungal growth have indirect effects on the expression of endogenous pathogen defense genes.

  1. Dietary supplementation with Cynodon dactylon (L.) enhances innate immunity and disease resistance of Indian major carp, Catla catla (Ham.).

    Science.gov (United States)

    Kaleeswaran, B; Ilavenil, S; Ravikumar, S

    2011-12-01

    Indian major carp (Catla catla) was subjected to study the immunostimulatory effects when the grass Cynodon dactylon(L) ethanolic extract administrated as feed supplement. C. catla was fed with 0% (Control), 0.05% (group I), 0.5% (group II) and 5% (group III) extract provided for 60 days. Blood samples were collected at every 10 days of interval up to 60 days for analyzing the non-specific humoral (lysozyme activity, antiprotease activity and haemolytic complement) and cellular (production of reactive oxygen and nitrogen species, myeloperoxidase activity) immune response study. The results indicate that C. dactylon ethanolic extract administered as feed supplement significantly (P < 0.05) enhanced most of the non-specific immune parameters tested. Among the experimental diet groups, significantly increased response of non-specific immunity was seen in group III (5%). Disease resistant analysis against Aeromonas hydrophila was performed in control group and plant extract treated fish for 7, 14, 21 and 28 days. Relative percent survival rate (RPS) was observed in treated samples, which is directly proportional to concentration of the extract. Additionally, electron microscopic studies and gelatin zymography for Matrix Metalo Proteinase (MMPs) were examined in spleen at 7th and 28th days of feeding. Administration of C. dactylon mixed diet delayed the lymphocyte destruction with positive ultrastructural changes. An induced stress (A. hydrophila infection) was observed by using MMPs expression, which was reduced in the experimental diet groups than the control. All these experimental results prove that C. dactylon ethanolic extract enhances the immunity of Catla fish. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. The Multifarious PGPR Serratia marcescens CDP-13 Augments Induced Systemic Resistance and Enhanced Salinity Tolerance of Wheat (Triticum aestivum L..

    Directory of Open Access Journals (Sweden)

    Rajnish Prakash Singh

    Full Text Available The present study demonstrates the plant growth promoting (PGP potential of a bacterial isolate CDP-13 isolated from 'Capparis decidua' plant, and its ability to protect plants from the deleterious effect of biotic and abiotic stressors. Based on 16S rRNA gene sequence analysis, the isolate was identified as Serratia marcescens. Among the PGP traits, the isolate was found to be positive for ACC deaminase activity, phosphate solubilization, production of siderophore, indole acetic acid production, nitrogen fixation, and ammonia production. CDP-13 showed growth at an increased salt (NaCl concentration of up to 6%, indicating its potential to survive and associate with plants growing in saline soil. The inoculation of S. marcescens enhanced the growth of wheat plant under salinity stress (150-200 mM. It significantly reduced inhibition of plant growth (15 to 85% caused by salt stressors. Application of CDP-13 also modulated concentration (20 to 75% of different osmoprotectants (proline, malondialdehyde, total soluble sugar, total protein content, and indole acetic acid in plants suggesting its role in enabling plants to tolerate salt stressors. In addition, bacterial inoculation also reduced the disease severity caused by fungal infection, which illustrated its ability to confer induced systemic resistance (ISR in host plants. Treatment of wheat plants with the test organism caused alteration in anti-oxidative enzymes activities (Superoxide dismutase, Catalase, and Peroxidase under various salinity levels, and therefore minimizes the salinity-induced oxidative damages to the plants. Colonization efficiency of strain CDP-13 was confirmed by CFU count, epi-fluorescence microscopy, and ERIC-PCR-based DNA fingerprinting approach. Hence, the study indicates that bacterium CDP-13 enhances plant growth, and has potential for the amelioration of salinity stress in wheat plants. Likewise, the results also provide insights into biotechnological approaches to

  3. Application of glycerol as a foliar spray activates the defence response and enhances disease resistance of Theobroma cacao.

    Science.gov (United States)

    Zhang, Yufan; Smith, Philip; Maximova, Siela N; Guiltinan, Mark J

    2015-01-01

    Previous work has implicated glycerol-3-phosphate (G3P) as a mobile inducer of systemic immunity in plants. We tested the hypothesis that the exogenous application of glycerol as a foliar spray might enhance the disease resistance of Theobroma cacao through the modulation of endogenous G3P levels. We found that exogenous application of glycerol to cacao leaves over a period of 4 days increased the endogenous level of G3P and decreased the level of oleic acid (18:1). Reactive oxygen species (ROS) were produced (a marker of defence activation) and the expression of many pathogenesis-related genes was induced. Notably, the effects of glycerol application on G3P and 18:1 fatty acid content, and gene expression levels, in cacao leaves were dosage dependent. A 100 mm glycerol spray application was sufficient to stimulate the defence response without causing any observable damage, and resulted in a significantly decreased lesion formation by the cacao pathogen Phytophthora capsici; however, a 500 mm glycerol treatment led to chlorosis and cell death. The effects of glycerol treatment on the level of 18:1 and ROS were constrained to the locally treated leaves without affecting distal tissues. The mechanism of the glycerol-mediated defence response in cacao and its potential use as part of a sustainable farming system are discussed. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  4. Electrical resistivity tomography to monitor enhanced biodegradation of hydrocarbons with Rhodococcus erythropolis T902.1 at a pilot scale

    Science.gov (United States)

    Masy, Thibaut; Caterina, David; Tromme, Olivier; Lavigne, Benoît; Thonart, Philippe; Hiligsmann, Serge; Nguyen, Frédéric

    2016-01-01

    Petroleum hydrocarbons (HC) represent the most widespread contaminants and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique (by biostimulation or bioaugmentation) strongly depends on the environment affected and is still difficult to predict a priori. In order to overcome these uncertainties, Electrical Resistivity Tomography (ERT) appears as a valuable non-invasive tool to detect soil heterogeneities and to monitor biodegradation. The main objective of this study was to isolate an electrical signal linked to an enhanced bacterial activity with ERT, in an aged HC-contaminated clay loam soil. To achieve this, a pilot tank was built to mimic field conditions. Compared to a first insufficient biostimulation phase, bioaugmentation with Rhodococcus erythropolis T902.1 led to a HC depletion of almost 80% (6900 to 1600 ppm) in 3 months in the center of the contaminated zone, where pollutants were less bioavailable. In the meantime, lithological heterogeneities and microbial activities (growth and biosurfactant production) were successively discriminated by ERT images. In the future, this cost-effective technique should be more and more transferred to the field in order to monitor biodegradation processes and assist in selecting the most appropriate remediation technique.

  5. Reprogramming of murine macrophages through TLR2 confers viral resistance via TRAF3-mediated, enhanced interferon production.

    Directory of Open Access Journals (Sweden)

    Darren J Perkins

    Full Text Available The cell surface/endosomal Toll-like Receptors (TLRs are instrumental in initiating immune responses to both bacteria and viruses. With the exception of TLR2, all TLRs and cytosolic RIG-I-like receptors (RLRs with known virus-derived ligands induce type I interferons (IFNs in macrophages or dendritic cells. Herein, we report that prior ligation of TLR2, an event previously shown to induce "homo" or "hetero" tolerance, strongly "primes" macrophages for increased Type I IFN production in response to subsequent TLR/RLR signaling. This occurs by increasing activation of the transcription factor, IFN Regulatory Factor-3 (IRF-3 that, in turn, leads to enhanced induction of IFN-β, while expression of other pro-inflammatory genes are suppressed (tolerized. In vitro or in vivo "priming" of murine macrophages with TLR2 ligands increase virus-mediated IFN induction and resistance to infection. This priming effect of TLR2 is mediated by the selective upregulation of the K63 ubiquitin ligase, TRAF3. Thus, we provide a mechanistic explanation for the observed antiviral actions of MyD88-dependent TLR2 and further define the role of TRAF3 in viral innate immunity.

  6. Electrical resistivity tomography to monitor enhanced biodegradation of hydrocarbons with Rhodococcus erythropolis T902.1 at a pilot scale.

    Science.gov (United States)

    Masy, Thibaut; Caterina, David; Tromme, Olivier; Lavigne, Benoît; Thonart, Philippe; Hiligsmann, Serge; Nguyen, Frédéric

    2016-01-01

    Petroleum hydrocarbons (HC) represent the most widespread contaminants and in-situ bioremediation remains a competitive treatment in terms of cost and environmental concerns. However, the efficiency of such a technique (by biostimulation or bioaugmentation) strongly depends on the environment affected and is still difficult to predict a priori. In order to overcome these uncertainties, Electrical Resistivity Tomography (ERT) appears as a valuable non-invasive tool to detect soil heterogeneities and to monitor biodegradation. The main objective of this study was to isolate an electrical signal linked to an enhanced bacterial activity with ERT, in an aged HC-contaminated clay loam soil. To achieve this, a pilot tank was built to mimic field conditions. Compared to a first insufficient biostimulation phase, bioaugmentation with Rhodococcus erythropolis T902.1 led to a HC depletion of almost 80% (6900 to 1600ppm) in 3months in the center of the contaminated zone, where pollutants were less bioavailable. In the meantime, lithological heterogeneities and microbial activities (growth and biosurfactant production) were successively discriminated by ERT images. In the future, this cost-effective technique should be more and more transferred to the field in order to monitor biodegradation processes and assist in selecting the most appropriate remediation technique. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Genetic Ablation of miR-33 Increases Food Intake, Enhances Adipose Tissue Expansion, and Promotes Obesity and Insulin Resistance

    Directory of Open Access Journals (Sweden)

    Nathan L. Price

    2018-02-01

    Full Text Available While therapeutic modulation of miRNAs provides a promising approach for numerous diseases, the promiscuous nature of miRNAs raises concern over detrimental off-target effects. miR-33 has emerged as a likely target for treatment of cardiovascular diseases. However, the deleterious effects of long-term anti-miR-33 therapies and predisposition of miR-33−/− mice to obesity and metabolic dysfunction exemplify the possible pitfalls of miRNA-based therapies. Our work provides an in-depth characterization of miR-33−/− mice and explores the mechanisms by which loss of miR-33 promotes insulin resistance in key metabolic tissues. Contrary to previous reports, our data do not support a direct role for SREBP-1-mediated lipid synthesis in promoting these effects. Alternatively, in adipose tissue of miR-33−/− mice, we observe increased pre-adipocyte proliferation, enhanced lipid uptake, and impaired lipolysis. Moreover, we demonstrate that the driving force behind these abnormalities is increased food intake, which can be prevented by pair feeding with wild-type animals.

  8. Propolis and Herba Epimedii extracts enhance the non-specific immune response and disease resistance of Chinese sucker, Myxocyprinus asiaticus.

    Science.gov (United States)

    Zhang, Guobin; Gong, Shiyuan; Yu, Denghang; Yuan, Hanwen

    2009-03-01

    The effect of traditional Chinese medicine (TCM) formulated from propolis and Herba Epimedii extracts at the ratio of 3:1 (w/w) on non-specific immune response of Chinese sucker (Myxocyprinus asiaticus) was investigated. Fish were fed diets containing 0 (control), 0.1%, 0.5% or 1.0% TCM extracts for five weeks. The respiratory burst and phagocytic activities of blood leukocytes, lysozyme and natural haemolytic complement activities in plasma were measured weekly. After five weeks of feeding, fish were infected with Aeromonas hydrophila and mortalities were recorded. Results of this study showed that feeding Chinese sucker with different dosage of TCM extracts stimulated respiratory burst activity, phagocytosis of phagocytic cells in blood and lysozyme activity in plasma. They had no effect on plasma natural haemolytic complement activity. All dosage of treated groups showed reduced mortality following A. hydrophila infection. Feed containing 0.5% TCM extracts was the most effective with the mortality of the fish significantly reduced by 35% compared to the control. The results indicate that propolis and Herba Epimedii extracts in combination enhances the non-specific immune response and disease resistance of Chinese sucker against A. hydrophila.

  9. Interaction of CDCP1 with HER2 Enhances HER2-Driven Tumorigenesis and Promotes Trastuzumab Resistance in Breast Cancer

    Directory of Open Access Journals (Sweden)

    Abdullah Alajati

    2015-04-01

    Full Text Available Understanding the molecular pathways that contribute to the aggressive behavior of HER2-positive breast cancers may aid in the development of novel therapeutic interventions. Here, we show that CDCP1 and HER2 are frequently co-overexpressed in metastatic breast tumors and associated with poor patient prognosis. HER2 and CDCP1 co-overexpression leads to increased transformation ability, cell migration, and tumor formation in vivo, and enhanced HER2 activation and downstream signaling in different breast cancer cell lines. Mechanistically, we demonstrate that CDCP1 binds to HER2 through its intracellular domain, thereby increasing HER2 interaction with the non-receptor tyrosine kinase c-SRC (SRC, leading to trastuzumab resistance. Taken together, our findings establish that CDCP1 is a modulator of HER2 signaling and a biomarker for the stratification of breast cancer patients with poor prognosis. Our results also provide a rationale for therapeutic targeting of CDCP1 in HER2-positive breast cancer patients.

  10. Chitosan and oligochitosan enhance ginger (Zingiber officinale Roscoe) resistance to rhizome rot caused by Fusarium oxysporum in storage.

    Science.gov (United States)

    Liu, Yiqing; Wisniewski, Michael; Kennedy, John F; Jiang, Yusong; Tang, Jianmin; Liu, Jia

    2016-10-20

    The ability of chitosan and oligochitosan to enhance ginger (Zingiber officinale) resistance to rhizome rot caused by Fusarium oxysporum in storage was investigated. Both chitosan and oligochitosan at 1 and 5g/L significantly inhibited rhizome rot, with the best control at 5g/L. Chitosan and oligochitosan applied at 5g/L also reduced weight loss, measured as a decrease in fresh weight, but did not affect soluble solids content or titratable acidity of rhizomes. The two compounds applied at 5g/L induced β-1,3-glucanase and phenylalanine ammonia-lyase enzyme activity and the transcript levels of their coding genes, as well as the total phenolic compounds in rhizome tissues. Therefore, the ability of chitosan and oligochitosan to reduce rot in stored rhizomes may be associated with their ability to induce defense responses in ginger. These results have practical implications for the application of chitosan and oligochitosan to harvested ginger rhizomes to reduce postharvest losses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Multifunctional substrate of Al alloy based on general hierarchical micro/nanostructures: superamphiphobicity and enhanced corrosion resistance

    Science.gov (United States)

    Li, Xuewu; Shi, Tian; Liu, Cong; Zhang, Qiaoxin; Huang, Xingjiu

    2016-10-01

    Aluminum alloys are vulnerable to penetrating and peeling failures in seawater and preparing a barrier coating to isolate the substrate from corrosive medium is an effective anticorrosion method. Inspired by the lotus leaves effect, a wetting alloy surface with enhanced anticorrosion behavior has been prepared via etch, deposition, and low-surface-energy modification. Results indicate that excellent superamphiphobicity has been achieved after the modification of the constructed hierarchical labyrinth-like microstructures and dendritic nanostructures. The as-prepared surface is also found with good chemical stability and mechanical durability. Furthermore, superior anticorrosion behaviors of the resultant samples in seawater are investigated by electrochemical measurements. Due to trapped air in micro/nanostructures, the newly presented solid-air-liquid contacting interface can help to resist the seawater penetration by greatly reducing the interface interaction between corrosive ions and the superamphiphobic surface. Finally, an optimized two-layer perceptron artificial neural network is set up to model and predict the cause-and-effect relationship between preparation conditions and the anticorrosion parameters. This work provides a great potential to extend the applications of aluminum alloys especially in marine engineering fields.

  12. Rated-voltage enhancement by fast-breaking of the fault current for a resistive superconducting fault current limiter component

    International Nuclear Information System (INIS)

    Park, C.-R.; Kim, M.-J.; Yu, S.-D.; Yim, S.-W.; Kim, H.-R.; Hyun, O.-B.

    2010-01-01

    Performance of a resistive superconducting fault current limiter (SFCL) component is usually limited by temperature rise associated with energy input by fault current application during a fault. Therefore, it is expected that short application of the fault current may enhance the power ratings of the component. This can be accomplished by a combination of a HTS component and a mechanical switch. The fast switch (FS) developed recently enables the fault duration to be as short as 1/2 cycle after a fault. Various second-generation (2G) high temperature superconductors (HTS) and YBCO thin films have been tested. The relation between the rated voltage V and the fault duration time t was found to be V 2 ∼ t -1 . Based upon the relation, we predict that when the FS break the fault current within 1/2 cycle after a fault, the amount of HTS components required to build an SFCL can be reduced by as much as about 60%, of that when breaking the fault current at three cycles.

  13. Calycophyllum spruceanum (Benth., the Amazonian “Tree of Youth” Prolongs Longevity and Enhances Stress Resistance in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Herbenya Peixoto

    2018-02-01

    Full Text Available The tree popularly known in Brazil as mulateiro or pau-mulato (Calycophyllum spruceanum (Benth. K. Schum. is deeply embedded in the herbal medicine of the Amazon region. Different preparations of the bark are claimed to have anti-aging, antioxidant, antimicrobial, emollient, wound healing, hemostatic, contraceptive, stimulant, and anti-diabetic properties. The current study aims to provide the first step towards a science-based evidence of the beneficial effects of C. spruceanum in the promotion of longevity and in the modulation of age-related markers. For this investigation, we used the model system Caenorhabditis elegans to evaluate in vivo antioxidant and anti-aging activity of a water extract from C. spruceanum. To chemically characterize the extract, HPLC MS (High Performance Liquid Chromatography Mass Spectrometry/MS analyses were performed. Five secondary metabolites were identified in the extract, namely gardenoside, 5-hydroxymorin, cyanidin, taxifolin, and 5-hydroxy-6-methoxycoumarin-7-glucoside. C. spruceanum extract was able to enhance stress resistance and to extend lifespan along with attenuation of aging-associated markers in C. elegans. The demonstrated bioactivities apparently depend on the DAF-16/FOXO pathway. The data might support the popular claims of mulateiro as the “tree of youth”, however more studies are needed to clarify its putative benefits to human health.

  14. Enhanced resistive switching and multilevel behavior in bilayered HfAlO/HfAlO{sub x} structures for non-volatile memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Faita, F. L., E-mail: fabriciofaita@gmail.com [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); Departamento de Física, Universidade Federal de Santa Catarina, Campus Trindade, 88040-900 Florianópolis, SC (Brazil); Silva, J. P. B., E-mail: josesilva@fisica.uminho.pt [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal); IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia, Faculdade de Ciências da Universidade do Porto, 4169-007 Porto (Portugal); Pereira, M.; Gomes, M. J. M. [Centre of Physics, University of Minho, Campus de Gualtar, 4710-057 Braga (Portugal)

    2015-12-14

    In this work, hafnium aluminum oxide (HfAlO) thin films were deposited by ion beam sputtering deposition technique on Si substrate. The presence of oxygen vacancies in the HfAlO{sub x} layer deposited in oxygen deficient environment is evidenced from the photoluminescence spectra. Furthermore, HfAlO(oxygen rich)/HfAlO{sub x}(oxygen poor) bilayer structures exhibit multilevel resistive switching (RS), and the switching ratio becomes more prominent with increasing the HfAlO layer thickness. The bilayer structure with HfAlO/HfAlO{sub x} thickness of 30/40 nm displays the enhanced multilevel resistive switching characteristics, where the high resistance state/intermediate resistance state (IRS) and IRS/low resistance state resistance ratios are ≈10{sup 2} and ≈5 × 10{sup 5}, respectively. The switching mechanisms in the bilayer structures were investigated by the temperature dependence of the three resistance states. This study revealed that the multilevel RS is attributed to the coupling of ionic conduction and the metallic conduction, being the first associated to the formation and rupture of conductive filaments related to oxygen vacancies and the second with the formation of a metallic filament. Moreover, the bilayer structures exhibit good endurance and stability in time.

  15. A strategic framework for proliferation resistance: a systematic approach for the identification and evaluation of technology opportunities to enhance the proliferation resistance of civilian nuclear energy systems

    International Nuclear Information System (INIS)

    Hassberger, J.A.; Isaac, T.; Schock, R.N.

    2001-01-01

    The United State Department of Energy Nuclear Energy Research Advisory Committee recently completed a study ''Technological Opportunities To Increase The Proliferation Resistance Of Global Civilian Nuclear Power Systems (TOPS)''. That effort included the development of a set of both intrinsic and extrinsic barriers to proliferation that technologies can directly impact. In this paper we will review these barriers as and framework for assisting in the evaluation of the relative proliferation resistance of various nuclear fuel cycles, technologies and alternatives. (author)

  16. Enhanced activity of carbohydrate- and lipid-metabolizing enzymes in insecticide-resistant populations of the maize weevil, Sitophilus zeamais.

    Science.gov (United States)

    Araújo, R A; Guedes, R N C; Oliveira, M G A; Ferreira, G H

    2008-08-01

    Insecticide resistance is frequently associated with fitness disadvantages in the absence of insecticides. However, intense past selection with insecticides may allow the evolution of fitness modifier alleles that mitigate the cost of insecticide resistance and their consequent fitness disadvantages. Populations of Sitophilus zeamais with different levels of susceptibility to insecticides show differences in the accumulation and mobilization of energy reserves. These differences may allow S. zeamais to better withstand toxic compounds without reducing the beetles' reproductive fitness. Enzymatic assays with carbohydrate- and lipid-metabolizing enzymes were, therefore, carried out to test this hypothesis. Activity levels of trehalase, glycogen phosphorylase, lipase, glycosidase and amylase were determined in two insecticide-resistant populations showing (resistant cost) or not showing (resistant no-cost) associated fitness cost, and in an insecticide-susceptible population. Respirometry bioassays were also carried out with these weevil populations. The resistant no-cost population showed significantly higher body mass and respiration rate than the other two populations, which were similar. No significant differences in glycogen phosphorylase and glycosidase were observed among the populations. Among the enzymes studied, trehalase and lipase showed higher activity in the resistant cost population. The results obtained in the assays with amylase also indicate significant differences in activity among the populations, but with higher activity in the resistant no-cost population. The inverse activity trends of lipases and amylases in both resistant populations, one showing fitness disadvantage without insecticide exposure and the other not showing it, may underlay the mitigation of insecticide resistance physiological costs observed in the resistant no-cost population. The higher amylase activity observed in the resistant no-cost population may favor energy storage

  17. The Arsenic Resistance-Associated Listeria Genomic Island LGI2 Exhibits Sequence and Integration Site Diversity and a Propensity for Three Listeria monocytogenes Clones with Enhanced Virulence.

    Science.gov (United States)

    Lee, Sangmi; Ward, Todd J; Jima, Dereje D; Parsons, Cameron; Kathariou, Sophia

    2017-11-01

    In the foodborne pathogen Listeria monocytogenes , arsenic resistance is encountered primarily in serotype 4b clones considered to have enhanced virulence and is associated with an arsenic resistance gene cluster within a 35-kb chromosomal region, Listeria genomic island 2 (LGI2). LGI2 was first identified in strain Scott A and includes genes putatively involved in arsenic and cadmium resistance, DNA integration, conjugation, and pathogenicity. However, the genomic localization and sequence content of LGI2 remain poorly characterized. Here we investigated 85 arsenic-resistant L. monocytogenes strains, mostly of serotype 4b. All but one of the 70 serotype 4b strains belonged to clonal complex 1 (CC1), CC2, and CC4, three major clones associated with enhanced virulence. PCR analysis suggested that 53 strains (62.4%) harbored an island highly similar to LGI2 of Scott A, frequently (42/53) in the same location as Scott A ( LMOf2365_2257 homolog). Random-primed PCR and whole-genome sequencing revealed seven novel insertion sites, mostly internal to chromosomal coding sequences, among strains harboring LGI2 outside the LMOf2365_2257 homolog. Interestingly, many CC1 strains harbored a noticeably diversified LGI2 (LGI2-1) in a unique location ( LMOf2365_0902 homolog) and with a novel additional gene. With few exceptions, the tested LGI2 genes were not detected in arsenic-resistant strains of serogroup 1/2, which instead often harbored a Tn 554 -associated arsenic resistance determinant not encountered in serotype 4b. These findings indicate that in L. monocytogenes , LGI2 has a propensity for certain serotype 4b clones, exhibits content diversity, and is highly promiscuous, suggesting an ability to mobilize various accessory genes into diverse chromosomal loci. IMPORTANCE Listeria monocytogenes is widely distributed in the environment and causes listeriosis, a foodborne disease with high mortality and morbidity. Arsenic and other heavy metals can powerfully shape the

  18. The dual PI3K/mTOR inhibitor PKI-587 enhances sensitivity to cetuximab in EGFR-resistant human head and neck cancer models.

    Science.gov (United States)

    D'Amato, V; Rosa, R; D'Amato, C; Formisano, L; Marciano, R; Nappi, L; Raimondo, L; Di Mauro, C; Servetto, A; Fusciello, C; Veneziani, B M; De Placido, S; Bianco, R

    2014-06-10

    Cetuximab is the only targeted agent approved for the treatment of head and neck squamous cell carcinomas (HNSCC), but low response rates and disease progression are frequently reported. As the phosphoinositide 3-kinase (PI3K) and the mammalian target of rapamycin (mTOR) pathways have an important role in the pathogenesis of HNSCC, we investigated their involvement in cetuximab resistance. Different human squamous cancer cell lines sensitive or resistant to cetuximab were tested for the dual PI3K/mTOR inhibitor PF-05212384 (PKI-587), alone and in combination, both in vitro and in vivo. Treatment with PKI-587 enhances sensitivity to cetuximab in vitro, even in the condition of epidermal growth factor receptor (EGFR) resistance. The combination of the two drugs inhibits cells survival, impairs the activation of signalling pathways and induces apoptosis. Interestingly, although significant inhibition of proliferation is observed in all cell lines treated with PKI-587 in combination with cetuximab, activation of apoptosis is evident in sensitive but not in resistant cell lines, in which autophagy is pre-eminent. In nude mice xenografted with resistant Kyse30 cells, the combined treatment significantly reduces tumour growth and prolongs mice survival. Phosphoinositide 3-kinase/mammalian target of rapamycin inhibition has an important role in the rescue of cetuximab resistance. Different mechanisms of cell death are induced by combined treatment depending on basal anti-EGFR responsiveness.

  19. Constitutive activation of jasmonate signaling in an Arabidopsis mutant correlates with enhanced resistance to Erysiphe cichoracearum, Pseudomonas syringae, and Myzus persicae.

    Science.gov (United States)

    Ellis, Christine; Karafyllidis, Ioannis; Turner, John G

    2002-10-01

    In Arabidopsis spp., the jasmonate (JA) response pathway generally is required for defenses against necrotrophic pathogens and chewing insects, while the salicylic acid (SA) response pathway is generally required for specific, resistance (R) gene-mediated defenses against both biotrophic and necrotrophic pathogens. For example, SA-dependent defenses are required for resistance to the biotrophic fungal pathogen Erysiphe cichoracearum UCSC1 and the bacterial pathogen Pseudomonas syringae pv. maculicola, and also are expressed during response to the green peach aphid Myzus persicae. However, recent evidence indicates that the expression of JA-dependent defenses also may confer resistance to E. cichoracearum. To confirm and to extend this observation, we have compared the disease and pest resistance of wild-type Arabidopsis plants with that of the mutants coil, which is insensitive to JA, and cev1, which has constitutive JA signaling. Measurements of the colonization of these plants by E. cichoracearum, P. syringae pv. maculicola, and M. persicae indicated that activation of the JA signal pathway enhanced resistance, and was associated with the activation of JA-dependent defense genes and the suppression of SA-dependent defense genes. We conclude that JA and SA induce alternative defense pathways that can confer resistance to the same pathogens and pests.

  20. Enhancement of corrosion resistance for plasma nitrided AISI 4140 steel by plain air plasma post-oxidizing

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jiqiang; Liu, Han; Ye, Xuemei [Jiangsu Key Laboratory of Materials Surface Technology, Changzhou University, Changzhou 213164 (China); Chai, Yating [Materials Research and Education Center, Auburn University, AL 36849 (United States); Hu, Jing, E-mail: jinghoo@126.com [Jiangsu Key Laboratory of Materials Surface Technology, Changzhou University, Changzhou 213164 (China); Materials Research and Education Center, Auburn University, AL 36849 (United States)

    2015-05-25

    Highlights: • Plain air was primarily used for plasma post-oxidation for AISI 4140 steel. • A thin iron oxide layer composed of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} was formed on top of the compound layer. • The ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} was closely related to the post-oxidizing conditions. • Post-oxidizing at 673 K for 60 min brought out highest ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} and optimum corrosion resistance. - Abstract: Plasma post-oxidizing was conducted immediately after plasma nitriding in the same equipment for AISI 4140 steel, and plain air was used as the oxygen bearing gas. The cross-sectional microstructures of the treated samples were observed by optical metallography and scanning electron microcopy (SEM), and the thickness of compound layer was measured accordingly. The phases were determined by X-ray diffraction (XRD), corrosion resistance was evaluated by electrochemical polarization, and the surface morphology before and after polarization test was also observed by SEM. Meanwhile, standard Gibbs free energy of the oxidation reactions existed in Fe–O system was calculated. The results show that a thin iron oxide layer composed of magnetite (Fe{sub 3}O{sub 4}) and hematite (Fe{sub 2}O{sub 3}) is formed on top of the compound layer during plasma post-oxidizing process, and the ratio of magnetite (Fe{sub 3}O{sub 4}) to hematite (Fe{sub 2}O{sub 3}) is depended on plasma post-oxidizing temperature and time. Highest ratio of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3} is obtained while post-oxidizing at 673 K for 60 min due to lower standard Gibbs free energy and appropriate forming rate for the formation of Fe{sub 3}O{sub 4} at this temperature. The thin oxide layer brings out significant enhancement of corrosion resistance, especially at higher ratios of Fe{sub 3}O{sub 4} to Fe{sub 2}O{sub 3}, due to the dense and adherent characteristic of Fe{sub 3}O{sub 4} oxide. Surface images of the post-oxidizing specimen

  1. Enhanced

    Directory of Open Access Journals (Sweden)

    Martin I. Bayala

    2014-06-01

    Full Text Available Land Surface Temperature (LST is a key parameter in the energy balance model. However, the spatial resolution of the retrieved LST from sensors with high temporal resolution is not accurate enough to be used in local-scale studies. To explore the LST–Normalised Difference Vegetation Index relationship potential and obtain thermal images with high spatial resolution, six enhanced image sharpening techniques were assessed: the disaggregation procedure for radiometric surface temperatures (TsHARP, the Dry Edge Quadratic Function, the Difference of Edges (Ts∗DL and three models supported by the relationship of surface temperature and water stress of vegetation (Normalised Difference Water Index, Normalised Difference Infrared Index and Soil wetness index. Energy Balance Station data and in situ measurements were used to validate the enhanced LST images over a mixed agricultural landscape in the sub-humid Pampean Region of Argentina (PRA, during 2006–2010. Landsat Thematic Mapper (TM and Moderate Resolution Imaging Spectroradiometer (EOS-MODIS thermal datasets were assessed for different spatial resolutions (e.g., 960, 720 and 240 m and the performances were compared with global and local TsHARP procedures. Results suggest that the Ts∗DL technique is the most adequate for simulating LST to high spatial resolution over the heterogeneous landscape of a sub-humid region, showing an average root mean square error of less than 1 K.

  2. Polymorphism in the Plasmodium falciparum chloroquine-resistance transporter protein links verapamil enhancement of chloroquine sensitivity with the clinical efficacy of amodiaquine

    Directory of Open Access Journals (Sweden)

    Warhurst David C

    2003-09-01

    Full Text Available Abstract Background Chloroquine accumulates in the acidic digestive vacuole of the intraerythrocytic malaria parasite, and prevents the detoxication of haematin released during haemoglobin digestion. Changes in protein PfCRT in the digestive vacuole membrane of growing intra-erythrocytic stages of Plasmodium falciparum are crucial for resistance. Expressed in yeast, PfCRT resembles an anion channel. Depressed anion channel function could increase intralysosomal pH to reduce entry of basic drug, or enhanced function could reduce drug interaction with target haematin. The most important resistance-associated change is from positively-charged lysine-76 to neutral threonine which could facilitate drug efflux through a putative channel. It has been proposed that the resistance-reversing effect of verapamil is due to hydrophobic binding to the mutated PfCRT protein, and replacement of the lost positive charge, which repels the access of 4-aminoquinoline cations, thus partially restoring sensitivity. Desethylamodiaquine, the active metabolite of amodiaquine, which has significant activity in chloroquine-resistance, may also act similarly on its own. Methods Changes in physicochemical parameters in different CQ-resistant PfCRT sequences are analysed, and correlations with drug activity on lines transfected with different alleles of the pfcrt gene are examined. Results and conclusions The results support the idea that PfCRT is a channel which, in resistant parasites, can allow efflux of chloroquine from the digestive vacuole. Activity of the chloroquine/verapamil combination and of desethylamodiaquine both correlate with the mean hydrophobicity of PfCRT residues 72-76. This may partly explain clinical-resistance to amodiaquine found in the first chloroquine-resistant malaria cases from South America and enables tentative prediction of amodiaquine's clinical activity against novel haplotypes of PfCRT.

  3. Enhanced resistance to fluoroquinolones in laboratory-grown mutants & clinical isolates of Shigella due to synergism between efflux pump expression & mutations in quinolone resistance determining region

    Directory of Open Access Journals (Sweden)

    Neelam Taneja

    2015-01-01

    Full Text Available Background & objectives: There is a worldwide emergence of fluoroquinolone resistance in Shigella species. To understand the molecular mechanisms associated with fluoroquinolone resistance, naturally occurring fluoroquinolone-resistant strains and laboratory-induced spontaneous mutants of Shigella spp. were used and the relative contributions of acrAB-tolC efflux pumps, gyrase and topoisomerase target gene mutations towards fluoroquinolone resistance were determined. Methods: Eight Shigella flexneri and six S. dysenteriae clinical isolates were studied. Three consecutive mutants resistant to ciprofloxacin for S. flexneri SFM1 (≥0.25 µg/ml, SFM2 (≥4 µg/ml and SFM3 (≥32 µg/ml were selected in 15 steps from susceptible isolates by serial exposure to increasing concentrations of nalidixic acid and ciprofloxacin. Similarly, two mutants for S. dysenteriae SDM1 (≥0.25 µg/ml and SDM2 (≥4 µg/ml were selected in eight steps. After PCR amplification sequence analyses of gyrase and topoisomerase target genes were performed. Expression of efflux genes acrA, acrB, acrR and tolC was measured using real-time PCR. Results: Mutations were observed in gyrA Ser [83]→Leu, Asp [87]→Asn/Gly, Val [196]→Ala and in parC Phe [93]→Val, Ser [80]→Ile, Asp [101]→Glu and Asp [110]→Glu. Overall, acrA and acrB overexpression was associated with fluoroquinolone resistance ( p0 <0.05; while tolC and acrR expression levels did not. Interpretation & conclusions: Fluoroquinolone resistance in Shigella spp. is the end product of either a single or a combination of mutations in QRDRs and/ or efflux activity. Novel polymorphisms were observed at Val [196]→Ala in gyrA in clinical isolates and Phe [93]→Val, Asp [101]→Glu, Asp [110]→Glu and in parC in majority of laboratory-grown mutants.

  4. Folate decorated dual drug loaded nanoparticle: role of curcumin in enhancing therapeutic potential of nutlin-3a by reversing multidrug resistance.

    Directory of Open Access Journals (Sweden)

    Manasi Das

    Full Text Available Retinoblastoma is the most common intraocular tumor in children. Malfunctioning of many signaling pathways regulating cell survival or apoptosis, make the disease more vulnerable. Notably, resistance to chemotherapy mediated by MRP-1, lung-resistance protein (LRP is the most challenging aspect to treat this disease. Presently, much attention has been given to the recently developed anticancer drug nutlin-3a because of its non-genotoxic nature and potency to activate tumor suppressor protein p53. However, being a substrate of multidrug resistance protein MRP1 and Pgp its application has become limited. Currently, research has step towards reversing Multi drug resistance (MDR by using curcumin, however its clinical relevance is restricted by plasma instability and poor bioavailability. In the present investigation we tried to encapsulate nutlin-3a and curcumin in PLGA nanoparticle (NPs surface functionalized with folate to enhance therapeutic potential of nutlin-3a by modulating MDR. We document that curcumin can inhibit the expression of MRP-1 and LRP gene/protein in a concentration dependent manner in Y79 cells. In vitro cellular cytotoxicity, cell cycle analysis and apoptosis studies were done to compare the effectiveness of native drugs (single or combined and single or dual drug loaded nanoparticles (unconjugated/folate conjugated. The result demonstrated an augmented therapeutic efficacy of targeted dual drug loaded NPs (Fol-Nut-Cur-NPs over other formulation. Enhanced expression or down regulation of proapoptotic/antiapoptotic proteins respectively and down-regulation of bcl2 and NFκB gene/protein by Fol-Nut-Cur-NPs substantiate the above findings. This is the first investigation exploring the role of curcumin as MDR modulator to enhance the therapeutic potentiality of nutlin-3a, which may opens new direction for targeting cancer with multidrug resistance phenotype.

  5. Bacillus pumilus KatX2 confers enhanced hydrogen peroxide resistance to a Bacillus subtilis PkatA::katX2 mutant strain.

    Science.gov (United States)

    Handtke, Stefan; Albrecht, Dirk; Zühlke, Daniela; Otto, Andreas; Becher, Dörte; Schweder, Thomas; Riedel, Kathrin; Hecker, Michael; Voigt, Birgit

    2017-04-26

    Bacillus pumilus cells exhibit a significantly higher resistance to hydrogen peroxide compared to closely related Bacilli like Bacillus subtilis. In this study we analyzed features of the catalase KatX2 of B. pumilus as one of the most important parts of the cellular response to hydrogen peroxide. KatX2, the vegetative catalase expressed in B. pumilus, was compared to the vegetative catalase KatA of B. subtilis. Data of our study demonstrate that B. pumilus can degrade toxic concentrations of hydrogen peroxide faster than B. subtilis. By replacing B. subtilis katA gene by katX2 we could significantly enhance its resistance to H 2 O 2 and its potential to eliminate this toxic compound. Mutant cells showed a 1.5- to 2-fold higher survival to toxic concentrations of hydrogen peroxide compared to wild type cells. Furthermore, we found reversible but also irreversible oxidations of the KatX2 protein which, in contrast to KatA, contains several cysteine residues. Our study indicates that the catalase KatX2 plays a major role in the increased resistance of B. pumilus to oxidative stress caused by hydrogen peroxide. Resistance to hydrogen peroxide of other Bacilli can be enhanced by exchanging the native catalase in the cells with katX2.

  6. Overexpression of NtPR-Q Up-Regulates Multiple Defense-Related Genes in Nicotiana tabacum and Enhances Plant Resistance to Ralstonia solanacearum

    Directory of Open Access Journals (Sweden)

    Yuanman Tang

    2017-11-01

    Full Text Available Various classes of plant pathogenesis-related proteins have been identified in the past several decades. PR-Q, a member of the PR3 family encoding chitinases, has played an important role in regulating plant resistance and preventing pathogen infection. In this paper, we functionally characterized NtPR-Q in tobacco plants and found that the overexpression of NtPR-Q in tobacco Yunyan87 resulted in higher resistance to Ralstonia solanacearum inoculation. Surprisingly, overexpression of NtPR-Q led to the activation of many defense-related genes, such as salicylic acid (SA-responsive genes NtPR1a/c, NtPR2 and NtCHN50, JA-responsive gene NtPR1b and ET production-associated genes NtACC Oxidase and NtEFE26. Consistent with the role of NtPR-Q in multiple stress responses, NtPR-Q transcripts were induced by the exogenous hormones SA, ethylene and methyl jasmonate, which could enhance the resistance of tobacco to R. solanacearum. Collectively, our results suggested that NtPR-Q overexpression led to the up-regulation of defense-related genes and enhanced plant resistance to R. solanacearum infection.

  7. Enhanced Corrosion Resistance and Interfacial Conductivity of TiC x/a-C Nanolayered Coatings via Synergy of Substrate Bias Voltage for Bipolar Plates Applications in PEMFCs.

    Science.gov (United States)

    Yi, Peiyun; Zhang, Weixin; Bi, Feifei; Peng, Linfa; Lai, Xinmin

    2018-06-06

    Proton-exchange membrane fuel cells are one kind of renewable and clean energy conversion device, whose metallic bipolar plates are one of the key components. However, high interfacial contact resistance and poor corrosion resistance are still great challenges for the commercialization of metallic bipolar plates. In this study, we demonstrated a novel strategy for depositing TiC x /amorphous carbon (a-C) nanolayered coatings by synergy of 60 and 300 V bias voltage to enhance corrosion resistance and interfacial conductivity. The synergistic effects of bias voltage on the composition, microstructure, surface roughness, electrochemical corrosion behaviors, and interfacial conductivity of TiC x /a-C coatings were explored. The results revealed that the columnar structures in the inner layer were suppressed and the surface became rougher with the 300 V a-C layer outside. The composition analysis indicated that the sp 2 content increased with an increase of 300 V sputtering time. Due to the synergy strategy of bias voltage, lower corrosion current densities were achieved both in potentiostatic polarization (1.6 V vs standard hydrogen electrode) and potentiodynamic polarization. With the increase of 300 V sputtering time, the interfacial conductivity was improved. The enhanced corrosion resistance and interfacial conductivity of the TiC x /a-C coatings would provide new opportunities for commercial bipolar plates.

  8. Baby leaf lettuce germplasm enhancement: developing diverse populations with resistance to bacterial leaf spot caused by Xanthomonas campestris pv. vitians

    Science.gov (United States)

    Baby leaf lettuce cultivars with resistance to bacterial leaf spot (BLS) caused by Xanthomonas campestris pv. vitians (Xcv) are needed to reduce crop losses. The objectives of this research were to assess the genetic diversity for BLS resistance in baby leaf lettuce cultivars and to select early gen...

  9. Enhanced pest resistance and increased phenolic production in maize callus transgenically expressing a maize chalcone isomerase -3 like gene

    Science.gov (United States)

    Significant losses in maize production are due to damage by insects and ear rot fungi. A gene designated as chalcone-isomerase-like, located in a quantitative trait locus for resistance to Fusarium ear rot fungi, was cloned from a Fusarium ear rot resistant inbred and transgenically expressed in mai...

  10. Enhancement of 1,3-bis(2-chloroethyl)-1-nitrosourea resistance by gamma-irradiation or drug pretreatment in rat hepatoma cells

    International Nuclear Information System (INIS)

    Habraken, Y.; Laval, F.

    1991-01-01

    Treatment of rat hepatoma cells (H4 cells) with various DNA-damaging agents increases the number of O6-methylguanine-DNA-methyltransferase (transferase) molecules per cell. Because the cellular resistance to chloroethylnitrosoureas depends on the number of transferase molecules, we studied the influence of pretreatment with gamma-irradiation, cis-dichlorodiammineplatinum(II), or 2-methyl-9-hydroxyellipticinium on the sensitivity of H4 cells to 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). The BCNU resistance depends on the gamma-ray dose and increases with time after irradiation: it is maximum when the drug is added 48 h after irradiation, which corresponds to the maximum enhancement of the transferase activity in the cells. Pretreatment with a single dose of cis-dichlorodiammineplatinum(II) or 2-methyl-9-hydroxyellipticinium also increases the cellular resistance to BCNU. This resistance is not due to a modification of the alkylation of the cellular DNA in the pretreated cells but is related to the increased transferase activity, as it is no longer observed when this activity is depleted by incubating the pretreated cells with the free base O6-methylguanine before BCNU treatment. These results suggest that tumor cells surviving after gamma-irradiation or drug treatment may become resistant to chemotherapy with chloroethylnitrosoureas

  11. Ectopic Expression of Hrf1 Enhances Bacterial Resistance via Regulation of Diterpene Phytoalexins, Silicon and Reactive Oxygen Species Burst in Rice

    Science.gov (United States)

    Zhong, Weigong; Yang, Jie; Okada, Kazunori; Yamane, Hisakazu; Zhang, Lei; Wang, Guang; Wang, Dong; Xiao, Shanshan; Chang, Shanshan; Qian, Guoliang; Liu, Fengquan

    2012-01-01

    Harpin proteins as elicitor derived from plant gram negative bacteria such as Xanthomonas oryzae pv. oryzae (Xoo), Erwinia amylovora induce disease resistance in plants by activating multiple defense responses. However, it is unclear whether phytoalexin production and ROS burst are involved in the disease resistance conferred by the expression of the harpinXoo protein in rice. In this article, ectopic expression of hrf1 in rice enhanced resistance to bacterial blight. Accompanying with the activation of genes related to the phytoalexin biosynthesis pathway in hrf1-transformed rice, phytoalexins quickly and consistently accumulated concurrent with the limitation of bacterial growth rate. Moreover, the hrf1-transformed rice showed an increased ability for ROS scavenging and decreased hydrogen peroxide (H2O2) concentration. Furthermore, the localization and relative quantification of silicon deposition in rice leaves was detected by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometer (EDS). Finally, the transcript levels of defense response genes increased in transformed rice. These results show a correlation between Xoo resistance and phytoalexin production, H2O2, silicon deposition and defense gene expression in hrf1-transformed rice. These data are significant because they provide evidence for a better understanding the role of defense responses in the incompatible interaction between bacterial disease and hrf1-transformed plants. These data also supply an opportunity for generating nonspecific resistance to pathogens. PMID:22970151

  12. IGF-1R and ErbB3/HER3 contribute to enhanced proliferation and carcinogenesis in trastuzumab-resistant ovarian cancer model

    International Nuclear Information System (INIS)

    Jia, Yanhan; Zhang, Yan; Qiao, Chunxia; Liu, Guijun; Zhao, Qing; Zhou, Tingting; Chen, Guojiang; Li, Yali; Feng, Jiannan; Li, Yan; Zhang, Qiuping; Peng, Hui

    2013-01-01

    Highlights: •We established trastuzumab-resistant cell line SKOV3/T. •SKOV3/T enhances proliferation and in vivo carcinogenesis. •IGF-1R and HER3 genes were up-regulated in SKOV3/T based on microarray analysis. •Targeting IGF-1R and/or HER3 inhibited the proliferation of SKOV3/T. •Therapies targeting IGF-1R and HER3 might be effective in ovarian cancer. -- Abstract: Trastuzumab (Herceptin®) has demonstrated clinical potential in several types of HER2-overexpressing human cancers. However, primary and acquired resistance occurs in many HER2-positive patients with regimens. To investigate the possible mechanism of acquired therapeutic resistance to trastuzumab, we have developed a preclinical model of human ovarian cancer cells, SKOV3/T, with the distinctive feature of stronger carcinogenesis. The differences in gene expression between parental and the resistant cells were explored by microarray analysis, of which IGF-1R and HER3 were detected to be key molecules in action. Their correctness was validated by follow-up experiments of RT-PCR, shRNA-mediated knockdown, downstream signal activation, cell cycle distribution and survival. These results suggest that IGF-1R and HER3 differentially regulate trastuzumab resistance and could be promising targets for trastuzumab therapy in ovarian cancer

  13. Ectopic expression of Hrf1 enhances bacterial resistance via regulation of diterpene phytoalexins, silicon and reactive oxygen species burst in rice.

    Directory of Open Access Journals (Sweden)

    Wenqi Li

    Full Text Available Harpin proteins as elicitor derived from plant gram negative bacteria such as Xanthomonas oryzae pv. oryzae (Xoo, Erwinia amylovora induce disease resistance in plants by activating multiple defense responses. However, it is unclear whether phytoalexin production and ROS burst are involved in the disease resistance conferred by the expression of the harpin(Xoo protein in rice. In this article, ectopic expression of hrf1 in rice enhanced resistance to bacterial blight. Accompanying with the activation of genes related to the phytoalexin biosynthesis pathway in hrf1-transformed rice, phytoalexins quickly and consistently accumulated concurrent with the limitation of bacterial growth rate. Moreover, the hrf1-transformed rice showed an increased ability for ROS scavenging and decreased hydrogen peroxide (H(2O(2 concentration. Furthermore, the localization and relative quantification of silicon deposition in rice leaves was detected by scanning electron microscopy (SEM and energy-dispersive X-ray spectrometer (EDS. Finally, the transcript levels of defense response genes increased in transformed rice. These results show a correlation between Xoo resistance and phytoalexin production, H(2O(2, silicon deposition and defense gene expression in hrf1-transformed rice. These data are significant because they provide evidence for a better understanding the role of defense responses in the incompatible interaction between bacterial disease and hrf1-transformed plants. These data also supply an opportunity for generating nonspecific resistance to pathogens.

  14. Human Lysozyme Synergistically Enhances Bactericidal Dynamics and Lowers the Resistant Mutant Prevention Concentration for Metronidazole to Helicobacter pylori by Increasing Cell Permeability

    Directory of Open Access Journals (Sweden)

    Xiaolin Zhang

    2016-10-01

    Full Text Available Metronidazole (MNZ is an effective agent that has been employed to eradicate Helicobacter pylori (H. pylori. The emergence of broad MNZ resistance in H. pylori has affected the efficacy of this therapeutic agent. The concentration of MNZ, especially the mutant prevention concentration (MPC, plays an important role in selecting or enriching resistant mutants and regulating therapeutic effects. A strategy to reduce the MPC that can not only effectively treat H. pylori but also prevent resistance mutations is needed. H. pylori is highly resistant to lysozyme. Lysozyme possesses a hydrolytic bacterial cell wall peptidoglycan and a cationic dependent mode. These effects can increase the permeability of bacterial cells and promote antibiotic absorption into bacterial cells. In this study, human lysozyme (hLYS was used to probe its effects on the integrity of the H. pylori outer and inner membranes using as fluorescent probe hydrophobic 1-N-phenyl-naphthylamine (NPN and the release of aspartate aminotransferase. Further studies using a propidium iodide staining method assessed whether hLYS could increase cell permeability and promote cell absorption. Finally, we determined the effects of hLYS on the bactericidal dynamics and MPC of MNZ in H. pylori. Our findings indicate that hLYS could dramatically increase cell permeability, reduce the MPC of MNZ for H. pylori, and enhance its bactericidal dynamic activity, demonstrating that hLYS could reduce the probability of MNZ inducing resistance mutations.

  15. IGF-1R and ErbB3/HER3 contribute to enhanced proliferation and carcinogenesis in trastuzumab-resistant ovarian cancer model

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Yanhan [Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei 430071 (China); Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Zhang, Yan [Department of Gynaecology and Obstetrics, PLA General Hospital, Beijing 100853 (China); Qiao, Chunxia; Liu, Guijun [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Zhao, Qing [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Department of Gynaecology and Obstetrics, PLA General Hospital, Beijing 100853 (China); Zhou, Tingting; Chen, Guojiang [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Li, Yali [Department of Gynaecology and Obstetrics, PLA General Hospital, Beijing 100853 (China); Feng, Jiannan; Li, Yan [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Zhang, Qiuping, E-mail: qpzhang@whu.edu.cn [Department of Immunology, School of Basic Medical Sciences, Wuhan University, Wuhan, Hubei 430071 (China); Peng, Hui, E-mail: p_h2002@hotmail.com [Department of Immunology, Institute of Basic Medical Sciences, Beijing 100850 (China); Cardiovascular Drug Research Center, Institute of Health and Environmental Medicine, Beijing 100850 (China)

    2013-07-12

    Highlights: •We established trastuzumab-resistant cell line SKOV3/T. •SKOV3/T enhances proliferation and in vivo carcinogenesis. •IGF-1R and HER3 genes were up-regulated in SKOV3/T based on microarray analysis. •Targeting IGF-1R and/or HER3 inhibited the proliferation of SKOV3/T. •Therapies targeting IGF-1R and HER3 might be effective in ovarian cancer. -- Abstract: Trastuzumab (Herceptin®) has demonstrated clinical potential in several types of HER2-overexpressing human cancers. However, primary and acquired resistance occurs in many HER2-positive patients with regimens. To investigate the possible mechanism of acquired therapeutic resistance to trastuzumab, we have developed a preclinical model of human ovarian cancer cells, SKOV3/T, with the distinctive feature of stronger carcinogenesis. The differences in gene expression between parental and the resistant cells were explored by microarray analysis, of which IGF-1R and HER3 were detected to be key molecules in action. Their correctness was validated by follow-up experiments of RT-PCR, shRNA-mediated knockdown, downstream signal activation, cell cycle distribution and survival. These results suggest that IGF-1R and HER3 differentially regulate trastuzumab resistance and could be promising targets for trastuzumab therapy in ovarian cancer.

  16. Hydrophobicity attainment and wear resistance enhancement on glass substrates by atmospheric plasma-polymerization of mixtures of an aminosilane and a fluorocarbon

    Energy Technology Data Exchange (ETDEWEB)

    Múgica-Vidal, Rodolfo, E-mail: rodolfo.mugica@alum.unirioja.es [Department of Mechanical Engineering, University of La Rioja, c/ Luis de Ulloa 20, 26004, Logroño, La Rioja (Spain); Alba-Elías, Fernando, E-mail: fernando.alba@unirioja.es [Department of Mechanical Engineering, University of La Rioja, c/ Luis de Ulloa 20, 26004, Logroño, La Rioja (Spain); Sainz-García, Elisa, E-mail: elisa.sainzg@unirioja.es [Department of Mechanical Engineering, University of La Rioja, c/ Luis de Ulloa 20, 26004, Logroño, La Rioja (Spain); Pantoja-Ruiz, Mariola, E-mail: mpruiz@ing.uc3m.es [Materials Science and Engineering Department, IAAB, Materials Performance Group, University Carlos III of Madrid, Av. Universidad 30, 28911, Leganés, Madrid (Spain)

    2015-08-30

    Graphical abstract: - Highlights: • APTES and PFH were used to coat glass by non-thermal atmospheric jet plasma. • A mixture of 75% of APTES and 25% PFH produced the best sample of this work. • Hydrophobicity was achieved by changes in surface morphology and chemistry. • Wear resistance was enhanced by the formation of siloxane groups. - Abstract: Mixtures of different proportions of two liquid precursors were subjected to plasma-polymerization by a non-thermal atmospheric jet plasma system in a search for a coating that achieves a hydrophobic character on a glass substrate and enhances its wear resistance. 1-Perfluorohexene (PFH) was chosen as a low-surface-energy precursor to promote a hydrophobic character. Aminopropyltriethoxysilane (APTES) was chosen for its contribution to the improvement of wear resistance by the formation of siloxane bonds. The objective of this work was to determine which of the precursors’ mixtures that were tested provides the coating with the most balanced enhancement of both hydrophobicity and wear resistance, given that coatings deposited with fluorocarbon-based precursors such as PFH are usually low in resistance to wear and coatings deposited with APTES are generally hydrophilic. The coatings obtained were analyzed by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Fourier Transform Infra-Red (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), static Water Contact Angle (WCA) measurements, tribological ball-on-disc tests and contact profilometry. A relationship between the achievement of a hydrophobic character and the modifications to roughness and surface morphology and the incorporation of fluorocarbon groups in the surface chemistry was observed. Also, it was seen that the wear resistance was influenced by the SiOSi content of the coatings. In turn, the SiOSi content appears to be directly related to the percentage of APTES used in the mixture of precursors. The best conjunction of

  17. Engineering metal-binding sites of bacterial CusF to enhance Zn/Cd accumulation and resistance by subcellular targeting

    International Nuclear Information System (INIS)

    Yu, Pengli; Yuan, Jinhong; Zhang, Hui; Deng, Xin; Ma, Mi; Zhang, Haiyan

    2016-01-01

    Highlights: • mCusF is specifically targeted to different subcellular compartments in Arabidopsis. • Plants expressing vacuole-targeted mCusF exhibit strongest Zn resistance. • All transgenic lines accumulate more Zn under Zn exposure. • All transgenic lines enhance root-to-shoot translocation of Cd. • Metal homeostasis is improved in mCusF plants under Cd exposure. - Abstract: The periplasmic protein CusF acts as a metallochaperone to mediate Cu resistance in Escherichia coli. CusF does not contain cysteine residues and barely binds to divalent cations. Here, we addressed effects of cysteine-substitution mutant (named as mCusF) of CusF on zinc/cadmium (Zn/Cd) accumulation and resistance. We targeted mCusF to different subcellular compartments in Arabidopsis. We found that plants expressing vacuole-targeted mCusF were more resistant to excess Zn than WT and plants with cell wall-targeted or cytoplasmic mCusF. Under long-term exposure to excess Zn, all transgenic lines accumulated more Zn (up to 2.3-fold) in shoots than the untransformed plants. Importantly, plants with cytoplasmic mCusF showed higher efficiency of Zn translocation from root to shoot than plants with secretory pathway-targeted-mCusF. Furthermore, the transgenic lines exhibited enhanced resistance to Cd and significant increase in root-to-shoot Cd translocation. We also found all transgenic plants greatly improved manganese (Mn) and iron (Fe) homeostasis under Cd exposure. Our results demonstrate heterologous expression of mCusF could be used to engineer a new phytoremediation strategy for Zn/Cd and our finding also deepen our insights into mechanistic basis for relieving Cd toxicity in plants through proper root/shoot partitioning mechanism and homeostatic accumulation of Mn and Fe.

  18. Engineering metal-binding sites of bacterial CusF to enhance Zn/Cd accumulation and resistance by subcellular targeting

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Pengli; Yuan, Jinhong [Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China); Zhang, Hui [Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China); Deng, Xin [Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637 (United States); Ma, Mi [Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China); Zhang, Haiyan, E-mail: hyz@ibcas.ac.cn [Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China)

    2016-01-25

    Highlights: • mCusF is specifically targeted to different subcellular compartments in Arabidopsis. • Plants expressing vacuole-targeted mCusF exhibit strongest Zn resistance. • All transgenic lines accumulate more Zn under Zn exposure. • All transgenic lines enhance root-to-shoot translocation of Cd. • Metal homeostasis is improved in mCusF plants under Cd exposure. - Abstract: The periplasmic protein CusF acts as a metallochaperone to mediate Cu resistance in Escherichia coli. CusF does not contain cysteine residues and barely binds to divalent cations. Here, we addressed effects of cysteine-substitution mutant (named as mCusF) of CusF on zinc/cadmium (Zn/Cd) accumulation and resistance. We targeted mCusF to different subcellular compartments in Arabidopsis. We found that plants expressing vacuole-targeted mCusF were more resistant to excess Zn than WT and plants with cell wall-targeted or cytoplasmic mCusF. Under long-term exposure to excess Zn, all transgenic lines accumulated more Zn (up to 2.3-fold) in shoots than the untransformed plants. Importantly, plants with cytoplasmic mCusF showed higher efficiency of Zn translocation from root to shoot than plants with secretory pathway-targeted-mCusF. Furthermore, the transgenic lines exhibited enhanced resistance to Cd and significant increase in root-to-shoot Cd translocation. We also found all transgenic plants greatly improved manganese (Mn) and iron (Fe) homeostasis under Cd exposure. Our results demonstrate heterologous expression of mCusF could be used to engineer a new phytoremediation strategy for Zn/Cd and our finding also deepen our insights into mechanistic basis for relieving Cd toxicity in plants through proper root/shoot partitioning mechanism and homeostatic accumulation of Mn and Fe.

  19. Enhanced Peroxide Resistance of In Vitro Mutagenized Fluorideresistant Klebsiella pneumoniae Ureases for Catalytic Buffering of Agent Decontamination Reactions

    National Research Council Canada - National Science Library

    Fry, Ilona J; DeFrank, Joseph J

    2004-01-01

    .... Fluoride-resistant (FR) ureases developed previously in our laboratory were >95% inhibited by 1% hydrogen peroxide. To overcome this problem, the FR mutant urease structural genes of Klebsiella pneumoniae were mutagenized in vitro in an E...

  20. Exogenous Salicylic Acid Enhances the Resistance of Wheat Seedlings to Hessian Fly (Diptera: Cecidomyiidae) Infestation Under Heat Stress.

    Science.gov (United States)

    Underwood, Joshua; Moch, John; Chen, Ming-Shun; Zhu, Lieceng

    2014-10-01

    Heat stress exerts significant impact on plant-parasite interactions. Phytohormones, such as salicylic acid (SA), play important roles in plant defense against parasite attacks. Here, we studied the impact of a combination of heat stress and exogenous SA on the resistance of wheat (Triticum aestivum L.) plants to the Hessian fly [Mayetiola destructor (Say)]. We found that the wheat cultivar 'Molly', which contains the resistance gene H13, lost resistance to Hessian fly under heat stress (40°C for 3 and 6 h), and that exogenous application of SA on Molly seedlings right before heat stress can partially prevent the loss of resistance of Molly plants under heat conditions. Our findings have significant implications for understanding the dynamics of plant-insect interactions in the context of heat stress. © 2014 Entomological Society of America.

  1. CyclinG1 Amplification Enhances Aurora Kinase Inhibitor-Induced Polyploid Resistance and Inhibition of Bcl-2 Pathway Reverses the Resistance

    Directory of Open Access Journals (Sweden)

    Wenfeng Zhang

    2017-08-01

    Full Text Available Background/Aims: CyclinG1 (CycG1 is frequently overexpressed in solid tumors and overexpression of CycG1 promotes cell survival upon paclitaxel exposure by inducing polyploidy. Whether and how CycG1 regulates polyploidization caused by small molecular targeted inhibitors remains unclear. Methods: Immunohistochemistry and immunoblotting were utilized to examine protein expression. Cell proliferation was measured by ATPlite assay, and cell cycle distribution and apoptosis were measured by flow cytometry and/or DNA fragmentation assays. Results: Overexpression of CycG1 in breast cancer cells caused apoptosis-resistant polyploidy upon treatment with Aurora kinase inhibitor, ZM447439 (ZM. Addition of ABT-263, a small-molecule BH3 mimetic, to ZM, produced a synergistic loss of cell viability with greater sustained tumor growth inhibition in breast cancer cell lines. Decrease of Mcl-1 and increase of NOXA caused by ZM treatment, were responsible for the synergy. Furthermore, CycG1 was highly expressed in Triple-Negative-Breast-Cancer patients treated with paclitaxel and was paralleled by decreased cell survival. Conclusion: CycG1 is a crucial factor in ZM-induced polyploidy resistance, and ABT-263/ZM combination hold therapeutic utility in the CycG1-amplified subset of breast cancer and CycG1, thus, is a promising target in breast cancer.

  2. Rapid label-free identification of Klebsiella pneumoniae antibiotic resistant strains by the drop-coating deposition surface-enhanced Raman scattering method

    Science.gov (United States)

    Cheong, Youjin; Kim, Young Jin; Kang, Heeyoon; Choi, Samjin; Lee, Hee Joo

    2017-08-01

    Although many methodologies have been developed to identify unknown bacteria, bacterial identification in clinical microbiology remains a complex and time-consuming procedure. To address this problem, we developed a label-free method for rapidly identifying clinically relevant multilocus sequencing typing-verified quinolone-resistant Klebsiella pneumoniae strains. We also applied the method to identify three strains from colony samples, ATCC70063 (control), ST11 and ST15; these are the prevalent quinolone-resistant K. pneumoniae strains in East Asia. The colonies were identified using a drop-coating deposition surface-enhanced Raman scattering (DCD-SERS) procedure coupled with a multivariate statistical method. Our workflow exhibited an enhancement factor of 11.3 × 106 to Raman intensities, high reproducibility (relative standard deviation of 7.4%), and a sensitive limit of detection (100 pM rhodamine 6G), with a correlation coefficient of 0.98. All quinolone-resistant K. pneumoniae strains showed similar spectral Raman shifts (high correlations) regardless of bacterial type, as well as different Raman vibrational modes compared to Escherichia coli strains. Our proposed DCD-SERS procedure coupled with the multivariate statistics-based identification method achieved excellent performance in discriminating similar microbes from one another and also in subtyping of K. pneumoniae strains. Therefore, our label-free DCD-SERS procedure coupled with the computational decision supporting method is a potentially useful method for the rapid identification of clinically relevant K. pneumoniae strains.

  3. Resistance exercise-induced increases in putative anabolic hormones do not enhance muscle protein synthesis or intracellular signalling in young men.

    Science.gov (United States)

    West, Daniel W D; Kujbida, Gregory W; Moore, Daniel R; Atherton, Philip; Burd, Nicholas A; Padzik, Jan P; De Lisio, Michael; Tang, Jason E; Parise, Gianni; Rennie, Michael J; Baker, Steven K; Phillips, Stuart M

    2009-11-01

    We aimed to determine whether exercise-induced elevations in systemic concentration of testosterone, growth hormone (GH) and insulin-like growth factor-1 (IGF-1) enhanced post-exercise myofibrillar protein synthesis (MPS) and phosphorylation of signalling proteins important in regulating mRNA translation. Eight young men (20 +/- 1.1 years, BMI = 26 +/- 3.5 kg m(-2)) completed two exercise protocols designed to maintain basal hormone concentrations (low hormone, LH) or elicit increases in endogenous hormones (high hormone, HH). In the LH protocol, participants performed a bout of unilateral resistance exercise with the elbow flexors. The HH protocol consisted of the same elbow flexor exercise with the contralateral arm followed immediately by high-volume leg resistance exercise. Participants consumed 25 g of protein after arm exercise to maximize MPS. Muscle biopsies and blood samples were taken as appropriate. There were no changes in serum testosterone, GH or IGF-1 after the LH protocol, whereas there were marked elevations after HH (testosterone, P anabolic hormones do not enhance fed-state anabolic signalling or MPS following resistance exercise. Local mechanisms are likely to be of predominant importance for the post-exercise increase in MPS.

  4. Enhanced chlorine resistance of tap water-adapted Legionella pneumophila as compared with agar medium-passaged strains.

    Science.gov (United States)

    Kuchta, J M; States, S J; McGlaughlin, J E; Overmeyer, J H; Wadowsky, R M; McNamara, A M; Wolford, R S; Yee, R B

    1985-07-01

    Previous studies have shown that bacteria maintained in a low-nutrient "natural" environment such as swimming pool water are much more resistant to disinfection by various chemical agents than strains maintained on rich media. In the present study a comparison was made of the chlorine (Cl2) susceptibility of hot-water tank isolates of Legionella pneumophila maintained in tap water and strains passaged on either nonselective buffered charcoal-yeast extract or selective differential glycine-vancomycin-polymyxin agar medium. Our earlier work has shown that environmental and clinical isolates of L. pneumophila maintained on agar medium are much more resistant to Cl2 than coliforms are. Under the present experimental conditions (21 degrees C, pH 7.6 to 8.0, and 0.25 mg of free residual Cl2 per liter, we found the tap water-maintained L. pneumophila strains to be even more resistant than the agar-passaged isolates. Under these conditions, 99% kill of tap water-maintained strains of L. pneumophila was usually achieved within 60 to 90 min compared with 10 min for agar-passaged strains. Samples from plumbing fixtures in a hospital yielded legionellae which were "super"-chlorine resistant when assayed under natural conditions. After one agar passage their resistance dropped to levels of comparable strains which had not been previously exposed to additional chlorination. These studies more closely approximate natural conditions than our previous work and show that tap water-maintained L. pneumophila is even more resistant to Cl2 than its already resistant agar medium-passaged counterpart.

  5. Effect of an avocado oil-enhanced diet (Persea americana) on sucrose-induced insulin resistance in Wistar rats.

    Science.gov (United States)

    Del Toro-Equihua, Mario; Velasco-Rodríguez, Raymundo; López-Ascencio, Raúl; Vásquez, Clemente

    2016-04-01

    A number of studies have been conducted to evaluate the effects of vegetable oils with varying percentages of monounsaturated and polyunsaturated fatty acids on insulin resistance. However, there is no report on the effect of avocado oil on this pathologic condition. The aim of this work was to evaluate the effect of avocado oil on sucrose-induced insulin resistance in Wistar rats. An experimental study was carried out on Wistar rats that were randomly assigned into six groups. Each group received a different diet over an 8-week period (n = 11 in each group): the control group was given a standard diet, and the other five groups were given the standard feed plus sucrose with the addition of avocado oil at 0%, 5%, 10%, 20%, and 30%, respectively. Variables were compared using Student t test and analysis of variance. Statistically significant difference was considered when p avocado oil showed lower insulin resistance (p = 0.022 and p = 0.024, respectively). Similar insulin resistance responses were observed in the control and 30% avocado oil addition groups (p = 0.85). Addition of 5-30% avocado oil lowered high sucrose diet-induced body weight gain in Wistar rats. It was thus concluded that glucose tolerance and insulin resistance induced by high sucrose diet in Wistar rats can be reduced by the dietary addition of 5-20% avocado oil. Copyright © 2016. Published by Elsevier B.V.

  6. Novel Chitinase Gene LOC_Os11g47510 from Indica Rice Tetep Provides Enhanced Resistance against Sheath Blight Pathogen Rhizoctonia solani in Rice

    Directory of Open Access Journals (Sweden)

    Tilak R. Sharma

    2017-04-01

    Full Text Available Sheath blight disease (ShB, caused by the fungus Rhizoctonia solani Kühn, is one of the most destructive diseases of rice (Oryza sativa L., causing substantial yield loss in rice. In the present study, a novel rice chitinase gene, LOC_Os11g47510 was cloned from QTL region of R. solani tolerant rice line Tetep and used for functional validation by genetic transformation of ShB susceptible japonica rice line Taipei 309 (TP309. The transformants were characterized using molecular and functional approaches. Molecular analysis by PCR using a set of primers specific to CaMv 35S promoter, chitinase and HptII genes confirmed the presence of transgene in transgenic plants which was further validated by Southern hybridization. Further, qRT-PCR analysis of transgenic plants showed good correlation between transgene expression and the level of sheath blight resistance among transformants. Functional complementation assays confirmed the effectiveness of the chitinase mediated resistance in all the transgenic TP309 plants with varying levels of enhanced resistance against R. solani. Therefore, the novel chitinase gene cloned and characterized in the present study from the QTL region of rice will be of significant use in molecular plant breeding program for developing sheath blight resistance in rice.

  7. Oral administration of Eclipta alba leaf aqueous extract enhances the non-specific immune responses and disease resistance of Oreochromis mossambicus.

    Science.gov (United States)

    Christybapita, D; Divyagnaneswari, M; Michael, R Dinakaran

    2007-10-01

    Immunostimulatory effects of the oral administration of the medicinal plant, Eclipta alba leaf extracts was studied in tilapia, Oreochromis mossambicus. For this purpose, fish were fed for 1, 2 or 3 weeks with diets containing E. alba leaf aqueous extract at 0, 0.01, 0.1 or 1% levels. After each week, non-specific humoral (lysozyme, antiprotease and complement) and cellular (myeloperoxidase content, production of reactive oxygen and nitrogen species) responses and disease resistance against Aeromonas hydrophila were determined. The results indicated that E. alba aqueous extract administered as feed supplement significantly enhanced most of the non-specific immune parameters tested. Among the humoral responses, lysozyme activity significantly increased after feeding with aqueous extract for 1, 2 or 3 weeks. No significant modulation was noticed in all the cellular responses tested after 3 weeks of feeding, while reactive oxygen species production and myeloperoxidase content showed significant enhancement after 1 week of feeding with aqueous extract. When challenged with A. hydrophila after 1, 2 or 3 weeks of feeding, the percentage mortality was significantly reduced in the treated fish. The highest dose of 1% gave better protection than the other doses with the relative percentage survival (RPS) values of 64, 75 and 32 after feeding for 1, 2 and 3 weeks respectively. The results indicate that dietary intake of E. alba aqueous leaf extract enhances the non-specific immune responses and disease resistance of O. mossambicus against A. hydrophila.

  8. Expression of a maize Myb transcription factor driven by a putative silk-specific promoter significantly enhances resistance to Helicoverpa zea in transgenic maize.

    Science.gov (United States)

    Johnson, Eric T; Berhow, Mark A; Dowd, Patrick F

    2007-04-18

    Hi II maize (Zea mays) plants were engineered to express maize p1 cDNA, a Myb transcription factor, controlled by a putative silk specific promoter, for secondary metabolite production and corn earworm resistance. Transgene expression did not enhance silk color, but about half of the transformed plant silks displayed browning when cut, which indicated the presence of p1-produced secondary metabolites. Levels of maysin, a secondary metabolite with insect toxicity, were highest in newly emerged browning silks. The insect resistance of transgenic silks was also highest at emergence, regardless of maysin levels, which suggests that other unidentified p1-induced molecules likely contributed to larval mortality. Mean survivor weights of corn earworm larvae fed mature browning transgenic silks were significantly lower than weights of those fed mature nonbrowning transgenic silks. Some transgenic pericarps browned with drying and contained similar molecules found in pericarps expressing a dominant p1 allele, suggesting that the promoter may not be silk-specific.

  9. Methods for estimation and enhancing of resistance of pressure vessel materials to fracture at different stages of service taking into account actual dimensions of the construction

    International Nuclear Information System (INIS)

    Pokrovsky, V.V.; Ivanchenko, A.G.

    1998-01-01

    In the present report a method is proposed for assessment of cracked materials fracture toughness over a wide range of temperatures taking into account the size-effect of structural elements. The procedure proposed was evaluated on specimens of different thicknesses (25... 150 mm) and geometries from the parent metal and welded joint metal of the WWER-Type nuclear reactor pressure vessels of different classes of strength. The method of enhancing of fracture resistance of pressure vessel materials has been develop which is based on warm prestressing of materials with cracks. The stability of the favourable effect of the warm prestressing has been, investigated and shown for the above steels after their long term (to 24000 hours) keeping under static loading and temperature of 350 deg C, under different conditions of cyclic loading, corrosive action. A model and calculation procedure are proposed for predicting the influence of thermomechanical loading conditions on the resistance of reactor steels to brittle fracture. (authors)

  10. Localized skin changes at the site of immunization with highly irradiated cercariae of Schistosoma mansoni are associated with enhanced resistance to a challenge infection

    International Nuclear Information System (INIS)

    Miller, K.L.; Smithers, S.R.

    1982-01-01

    The level of immunity to a percutaneous cercarial challenge with Schistosoma mansoni was assayed 4-6 weeks after immunization of mice with highly irradiated (20 krad.) cercariae or schistosomula. When immunization and challenge occurred through the same skin site, resistance, particularly that which occurred in the skin, was greater than that observed when immunization and challenge occurred in different sites. The enhanced resistance is believed to be due to localized changes in the skin; 4 weeks after exposure to irradiated cercariae, abdominal skin is characterized by a thickened epidermis, changes in the ground substance and a cellular infiltration of the dermis. A convenient mouse model is described in which one or both ear pinnae are exposed to irradiated cercariae and a percutaneous challenge is given via the abdomen, thus eliminating the effects of local skin changes. In this model, the majority of the challenge infection which succumbs to the immune response appears to be killed in the skin. (author)

  11. Enhancing caries resistance with a short-pulsed CO2 9.3-μm laser: a laboratory study (Conference Presentation)

    Science.gov (United States)

    Rechmann, Peter; Rechmann, Beate M.; Groves, William H.; Le, Charles; Rapozo-Hilo, Marcia L.; Featherstone, John D. B.

    2016-02-01

    The objective of this laboratory study was to test whether irradiation with a new 9.3µm microsecond short-pulsed CO2-laser enhances enamel caries resistance with and without additional fluoride applications. 101 human enamel samples were divided into 7 groups. Each group was treated with different laser parameters (Carbon-dioxide laser, wavelength 9.3µm, 43Hz pulse-repetition rate, pulse duration between 3μs to 7μs (1.5mJ/pulse to 2.9mJ/pulse). Using a pH-cycling model and cross-sectional microhardness testing determined the mean relative mineral loss delta Z (∆Z) for each group. The pH-cycling was performed with or without additional fluoride. The CO2 9.3μm short-pulsed laser energy rendered enamel caries resistant with and without additional fluoride use.

  12. Enhanced virus resistance in transgenic maize expressing a dsRNA-specific endoribonuclease gene from E. coli.

    Directory of Open Access Journals (Sweden)

    Xiuling Cao

    Full Text Available Maize rough dwarf disease (MRDD, caused by several Fijiviruses in the family Reoviridae, is a global disease that is responsible for substantial yield losses in maize. Although some maize germplasm have low levels of polygenic resistance to MRDD, highly resistant cultivated varieties are not available for agronomic field production in China. In this work, we have generated transgenic maize lines that constitutively express rnc70, a mutant E. coli dsRNA-specific endoribonuclease gene. Transgenic lines were propagated and screened under field conditions for 12 generations. During three years of evaluations, two transgenic lines and their progeny were challenged with Rice black-streaked dwarf virus (RBSDV, the causal agent of MRDD in China, and these plants exhibited reduced levels of disease severity. In two normal years of MRDD abundance, both lines were more resistant than non-transgenic plants. Even in the most serious MRDD year, six out of seven progeny from one line were resistant, whereas non-transgenic plants were highly susceptible. Molecular approaches in the T12 generation revealed that the rnc70 transgene was integrated and expressed stably in transgenic lines. Under artificial conditions permitting heavy virus inoculation, the T12 progeny of two highly resistant lines had a reduced incidence of MRDD and accumulation of RBSDV in infected plants. In addition, we confirmed that the RNC70 protein could bind directly to RBSDV dsRNA in vitro. Overall, our data show that RNC70-mediated resistance in transgenic maize can provide efficient protection against dsRNA virus infection.

  13. Expression of a novel antimicrobial peptide Penaeidin4-1 in creeping bentgrass (Agrostis stolonifera L. enhances plant fungal disease resistance.

    Directory of Open Access Journals (Sweden)

    Man Zhou

    Full Text Available BACKGROUND: Turfgrass species are agriculturally and economically important perennial crops. Turfgrass species are highly susceptible to a wide range of fungal pathogens. Dollar spot and brown patch, two important diseases caused by fungal pathogens Sclerotinia homoecarpa and Rhizoctonia solani, respectively, are among the most severe turfgrass diseases. Currently, turf fungal disease control mainly relies on fungicide treatments, which raises many concerns for human health and the environment. Antimicrobial peptides found in various organisms play an important role in innate immune response. METHODOLOGY/PRINCIPAL FINDINGS: The antimicrobial peptide - Penaeidin4-1 (Pen4-1 from the shrimp, Litopenaeus setiferus has been reported to possess in vitro antifungal and antibacterial activities against various economically important fungal and bacterial pathogens. In this study, we have studied the feasibility of using this novel peptide for engineering enhanced disease resistance into creeping bentgrass plants (Agrostis stolonifera L., cv. Penn A-4. Two DNA constructs were prepared containing either the coding sequence of a single peptide, Pen4-1 or the DNA sequence coding for the transit signal peptide of the secreted tobacco AP24 protein translationally fused to the Pen4-1 coding sequence. A maize ubiquitin promoter was used in both constructs to drive gene expression. Transgenic turfgrass plants containing different DNA constructs were generated by Agrobacterium-mediated transformation and analyzed for transgene insertion and expression. In replicated in vitro and in vivo experiments under controlled environments, transgenic plants exhibited significantly enhanced resistance to dollar spot and brown patch, the two major fungal diseases in turfgrass. The targeting of Pen4-1 to endoplasmic reticulum by the transit peptide of AP24 protein did not significantly impact disease resistance in transgenic plants. CONCLUSION/SIGNIFICANCE: Our results

  14. Prunus domestica pathogenesis-related protein-5 activates the defense response pathway and enhances the resistance to fungal infection.

    Directory of Open Access Journals (Sweden)

    Ashraf El-kereamy

    Full Text Available Pathogenesis-related protein-5 (PR-5 has been implicated in plant disease resistance and its antifungal activity has been demonstrated in some fruit species. However, their roles, especially their interactions with the other defense responses in plant cells, are still not fully understood. In this study, we have cloned and characterized a new PR-5 cDNA named PdPR5-1 from the European plum (Prunus domestica. Expression of PdPR5-1 was studied in different cultivars varying in resistance to the brown rot disease caused by the necrotrophic fungus Monilinia fructicola. In addition transgenic Arabidopsis, ectopically expressing PdPR5-1 was used to study its role in other plant defense responses after fungal infection. We show that the resistant cultivars exhibited much higher levels of transcripts than the susceptible cultivars during fruit ripening. However, significant rise in the transcript levels after infection with M. fructicola was observed in the susceptible cultivars too. Transgenic Arabidopsis plants exhibited more resistance to Alternaria brassicicola. Further, there was a significant increase in the transcripts of genes involved in the phenylpropanoid biosynthesis pathway such as phenylalanine ammonia-lyase (PAL and phytoalexin (camalexin pathway leading to an increase in camalexin content after fungal infection. Our results show that PdPR5-1 gene, in addition to its anti-fungal properties, has a possible role in activating other defense pathways, including phytoalexin production.

  15. Enhancement of host defense against pathogens by antimicrobial peptides : a new approach to combat microbial drug resistance

    NARCIS (Netherlands)

    Does, Anne Margaretha van der

    2011-01-01

    Due to their abilities to eliminate pathogens and modulate host’s immune responses, antimicrobial peptides are considered as potential alternatives for the treatment of infections with (multi-drug resistant) pathogens. In this thesis the immunomodulatory actions of two peptides have been

  16. Resistant starch and protein intake enhances fat oxidation and feelings of fullness in lean and overweight/obese women

    DEFF Research Database (Denmark)

    Gentile, Christopher L; Ward, Emery; Holst, Jens Juul

    2015-01-01

    and overweight/obese women. METHODS: Women of varying levels of adiposity consumed one of four pancake test meals in a single-blind, randomized crossover design: 1) waxy maize (control) starch (WMS); 2) waxy maize starch and whey protein (WMS+WP); 3) resistant starch (RS); or 4) RS and whey protein (RS...

  17. Overexpression of a New Chitinase Gene EuCHIT2 Enhances Resistance to Erysiphe cichoracearum DC. in Tobacco Plants

    Directory of Open Access Journals (Sweden)

    Xuan Dong

    2017-11-01

    Full Text Available In this study, we cloned a new chitinase gene, EuCHIT2, from Eucommia ulmoides Oliver (E. ulmoides using rapid amplification of cDNA ends (RACE technology and constructed an overexpression vector, pSH-35S-EuCHIT2, to introduce it into tobacco (Nicotiana tabacum cv. Xanthi. Resistance to Erysiphe cichoracearum de Candolle (E.cichoracearum DC and molecular mechanisms in the transgenic tobacco were determined by drop inoculation, spore counting, determination of physicochemical indicators, and analysis of gene expression. The chitinase activity and resistance to E. cichoracearum DC were significantly higher in the transgenic tobacco than in wild-type tobacco (p < 0.05. The activities of peroxidase (POD and catalase (CAT, after inoculation with E. cichoracearum DC, were higher in the transgenic tobacco than in the wild-type. Conversely, the malondialdehyde (MDA content was significantly lower in the transgenic tobacco than the wild-type before and after inoculation. In addition, our study also indicated that the resistance to E. cichoracearum DC might involve the salicylic acid (SA and jasmonic acid (JA pathways, because the expression levels of pathogenesis-related gene 1 (PR-1a and coronatine-insensitive 1 (COI1 were significantly increased and decreased, respectively, after inoculation with E. cichoracearum DC. The present study supports the notion that PR-1a and POD participate in resistance to E. cichoracearum DC in the transgenic tobacco plants.

  18. Nitric oxide donor seed priming enhances defense responses and induces resistance against pearl millet downy mildew disease

    DEFF Research Database (Denmark)

    Manjunatha, G.; Raj, S. Niranjan; Shetty, Nandini Prasad

    2008-01-01

    experiments with NO donors showed no adverse effect either on the host or pathogen. Aqueous SNP seed treatment with or without polyethylene glycol (PEG) priming was the most effective in inducing the host resistance against downy mildew both under greenhouse and field conditions. Potassium Ferrocyanide...

  19. Enhanced oxygen vacancy diffusion in Ta2O5 resistive memory devices due to infinitely adaptive crystal structure

    Science.gov (United States)

    Jiang, Hao; Stewart, Derek A.

    2016-04-01

    Metal oxide resistive memory devices based on Ta2O5 have demonstrated high switching speed, long endurance, and low set voltage. However, the physical origin of this improved performance is still unclear. Ta2O5 is an important archetype of a class of materials that possess an adaptive crystal structure that can respond easily to the presence of defects. Using first principles nudged elastic band calculations, we show that this adaptive crystal structure leads to low energy barriers for in-plane diffusion of oxygen vacancies in λ phase Ta2O5. Identified diffusion paths are associated with collective motion of neighboring atoms. The overall vacancy diffusion is anisotropic with higher diffusion barriers found for oxygen vacancy movement between Ta-O planes. Coupled with the fact that oxygen vacancy formation energy in Ta2O5 is relatively small, our calculated low diffusion barriers can help explain the low set voltage in Ta2O5 based resistive memory devices. Our work shows that other oxides with adaptive crystal structures could serve as potential candidates for resistive random access memory devices. We also discuss some general characteristics for ideal resistive RAM oxides that could be used in future computational material searches.

  20. Sustainability of Water Reclamation: Long-Term Recharge with Reclaimed Wastewater Does Not Enhance Antibiotic Resistance in Sediment Bacteria

    Directory of Open Access Journals (Sweden)

    Jean E. McLain

    2014-03-01

    Full Text Available Wastewater reclamation for municipal irrigation is an increasingly attractive option for extending water supplies. However, public health concerns include the potential for development of antibiotic resistance (AR in environmental bacteria after exposure to residual pharmaceuticals in reclaimed water. Though scientific studies have reported high levels of AR in soils irrigated with wastewater, these works often fail to address the soil resistome, or the natural occurrence of AR. This study compared AR patterns in sediment Enterococcus isolated from water storage basins containing either reclaimed water or groundwater in central Arizona. Resistance to 16 antibiotics was quantified in isolates to a depth of 30 cm. Results reveal high levels of resistance to certain antibiotics, including lincomycin, ciprofloxacin, and erythromycin, exists in sediments regardless of the water source (groundwater, reclaimed water, and higher AR was not detectable in reclaimed water sediments. Furthermore, multiple-antibiotic-resistance (MAR was substantially reduced in isolates from reclaimed water sediments, compared to freshwater sediment isolates. Comparing the development of AR in sediment bacteria at these two sites will increase awareness of the environmental and public health impacts of using reclaimed water for irrigation of municipal areas, and illustrates the necessity for control sites in studies examining AR development in environmental microbiota.

  1. Enhancement of nonspecific resistance by liposome-encapsulated immunomodulators does not affect skin graft rejection in mice

    NARCIS (Netherlands)

    Hagen, ten T.L.M.; Vossen, A.C.T.M.; Vianen, van W.; Tibbe, G.J.M.; Savelkoul, H.F.J.; Heremans, H.; Bakker-Woudenberg, I.A.J.M.

    1995-01-01

    Administration of liposome-encapsulated immunomodulating agents muramyl tripeptide phosphatidyl ethanolamine (LE-MTPPE) or interferon-gamma (LE-IFN-gamma), or co-encapsulated MTPPE and IFN-gamma (LE-(MTPPE/IFN-gamma)) resulted in a dramatic increase of the nonspecific antimicrobial resistance in

  2. Mixed species biofilms of Listeria monocytogenes and Lactobacillus plantarum show enhanced resistance to benzalkonium chloride and peracetic acid

    NARCIS (Netherlands)

    Veen, van der S.; Abee, T.

    2011-01-01

    We investigated the formation of single and mixed species biofilms of Listeria monocytogenes strains EGD-e and LR-991, with Lactobacillus plantarum WCFS1 as secondary species, and their resistance to the disinfectants benzalkonium chloride and peracetic acid. Modulation of growth, biofilm formation,

  3. Silicon-enhanced resistance to cadmium toxicity in Brassica chinensis L. is attributed to Si-suppressed cadmium uptake and transport and Si-enhanced antioxidant defense capacity

    Energy Technology Data Exchange (ETDEWEB)

    Song Alin [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Li Zhaojun [Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Zhang Jie [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Xue Gaofeng; Fan Fenliang [Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Liang Yongchao, E-mail: ycliang@caas.ac.cn [College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 (China); Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081 (China); Key Laboratory of Oasis Eco-Agriculture, College of Agriculture, Shihezi University, Shihezi 832003 (China)

    2009-12-15

    A series of hydroponics experiments were performed to investigate roles of silicon (Si) in enhancing cadmium (Cd) tolerance in two pakchoi (Brassica chinensis L.) cultivars: i.e. cv. Shanghaiqing, a Cd-sensitive cultivar, and cv. Hangyoudong, a Cd-tolerant cultivar. Plants were grown under 0.5 and 5 mg Cd L{sup -1} Cd stress without or with 1.5 mM Si. Plant growth of the Cd-tolerant cultivar was stimulated at the lower Cd level, but was decreased at the higher Cd level when plants were treated with Cd for one week. However, Plant growth was severely inhibited at both Cd levels as stress duration lasted for up to three weeks. Plant growth of the Cd-sensitive cultivar was severely inhibited at both Cd levels irrespective of Cd stress duration. Addition of Si increased shoot and root biomass of both cultivars at both Cd levels and decreased Cd uptake and root-to-shoot transport. Superoxide dismutase, catalase and ascorbate peroxidase activities decreased, but malondialdehyde and H{sub 2}O{sub 2} concentrations increased at the higher Cd level, which were counteracted by Si added. Ascorbic acid, glutathione and non-protein thiols concentrations increased at the higher Cd level, which were further intensified by addition of Si. The effects of Si and Cd on the antioxidant enzyme activity were further verified by isoenzyme analysis. Silicon was more effective in enhancing Cd tolerance in the Cd-tolerant cultivar than in the Cd-sensitive cultivar. It can be concluded that Si-enhanced Cd tolerance in B. chinensis is attributed mainly to Si-suppressed Cd uptake and root-to-shoot Cd transport and Si-enhanced antioxidant defense activity.

  4. Silicon-enhanced resistance to cadmium toxicity in Brassica chinensis L. is attributed to Si-suppressed cadmium uptake and transport and Si-enhanced antioxidant defense capacity

    International Nuclear Information System (INIS)

    Song Alin; Li Zhaojun; Zhang Jie; Xue Gaofeng; Fan Fenliang; Liang Yongchao

    2009-01-01

    A series of hydroponics experiments were performed to investigate roles of silicon (Si) in enhancing cadmium (Cd) tolerance in two pakchoi (Brassica chinensis L.) cultivars: i.e. cv. Shanghaiqing, a Cd-sensitive cultivar, and cv. Hangyoudong, a Cd-tolerant cultivar. Plants were grown under 0.5 and 5 mg Cd L -1 Cd stress without or with 1.5 mM Si. Plant growth of the Cd-tolerant cultivar was stimulated at the lower Cd level, but was decreased at the higher Cd level when plants were treated with Cd for one week. However, Plant growth was severely inhibited at both Cd levels as stress duration lasted for up to three weeks. Plant growth of the Cd-sensitive cultivar was severely inhibited at both Cd levels irrespective of Cd stress duration. Addition of Si increased shoot and root biomass of both cultivars at both Cd levels and decreased Cd uptake and root-to-shoot transport. Superoxide dismutase, catalase and ascorbate peroxidase activities decreased, but malondialdehyde and H 2 O 2 concentrations increased at the higher Cd level, which were counteracted by Si added. Ascorbic acid, glutathione and non-protein thiols concentrations increased at the higher Cd level, which were further intensified by addition of Si. The effects of Si and Cd on the antioxidant enzyme activity were further verified by isoenzyme analysis. Silicon was more effective in enhancing Cd tolerance in the Cd-tolerant cultivar than in the Cd-sensitive cultivar. It can be concluded that Si-enhanced Cd tolerance in B. chinensis is attributed mainly to Si-suppressed Cd uptake and root-to-shoot Cd transport and Si-enhanced antioxidant defense activity.

  5. Development of transgenic cotton lines expressing Allium sativum agglutinin (ASAL) for enhanced resistance against major sap-sucking pests.

    Science.gov (United States)

    Vajhala, Chakravarthy S K; Sadumpati, Vijaya Kumar; Nunna, Hariprasad Rao; Puligundla, Sateesh Kumar; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

    2013-01-01

    Mannose-specific Allium sativum leaf agglutinin encoding gene (ASAL) and herbicide tolerance gene (BAR) were introduced into an elite cotton inbred line (NC-601) employing Agrobacterium-mediated genetic transformation. Cotton transformants were produced from the phosphinothricin (PPT)-resistant shoots obtained after co-cultivation of mature embryos with the Agrobacterium strain EHA105 harbouring recombinant binary vector pCAMBIA3300-ASAL-BAR. PCR and Southern blot analysis confirmed the presence and stable integration of ASAL and BAR genes in various transformants of cotton. Basta leaf-dip assay, northern blot, western blot and ELISA analyses disclosed variable expression of BAR and ASAL transgenes in different transformants. Transgenes, ASAL and BAR, were stably inherited and showed co-segregation in T1 generation in a Mendelian fashion for both PPT tolerance and insect resistance. In planta insect bioassays on T2 and T3 homozygous ASAL-transgenic lines revealed potent entomotoxic effects of ASAL on jassid and whitefly insects, as evidenced by significant decreases in the survival, development and fecundity of the insects when compared to the untransformed controls. Furthermore, the transgenic cotton lines conferred higher levels of resistance (1-2 score) with minimal plant damage against these major sucking pests when bioassays were carried out employing standard screening techniques. The developed transgenics could serve as a potential genetic resource in recombination breeding aimed at improving the pest resistance of cotton. This study represents the first report of its kind dealing with the development of transgenic cotton resistant to two major sap-sucking insects.

  6. Transgenic wheat expressing Thinopyrum intermedium MYB transcription factor TiMYB2R-1 shows enhanced resistance to the take-all disease.

    Science.gov (United States)

    Liu, Xin; Yang, Lihua; Zhou, Xianyao; Zhou, Miaoping; Lu, Yan; Ma, Lingjian; Ma, Hongxiang; Zhang, Zengyan

    2013-05-01

    The disease take-all, caused by the fungus Gaeumannomyces graminis, is one of the most destructive root diseases of wheat worldwide. Breeding resistant cultivars is an effective way to protect wheat from take-all. However, little progress has been made in improving the disease resistance level in commercial wheat cultivars. MYB transcription factors play important roles in plant responses to environmental stresses. In this study, an R2R3-MYB gene in Thinopyrum intermedium, TiMYB2R-1, was cloned and characterized. The gene sequence includes two exons and an intron. The expression of TiMYB2R-1 was significantly induced following G. graminis infection. An in vitro DNA binding assay proved that TiMYB2R-1 protein could bind to the MYB-binding site cis-element ACI. Subcellular localization assays revealed that TiMYB2R-1 was localized in the nucleus. TiMYB2R-1 transgenic wheat plants were generated, characterized molecularly, and evaluated for take-all resistance. PCR and Southern blot analyses confirmed that TiMYB2R-1 was integrated into the genomes of three independent transgenic wheat lines by distinct patterns and the transgene was heritable. Reverse transcription-PCR and western blot analyses revealed that TiMYB2R-1 was highly expressed in the transgenic wheat lines. Based on disease response assessments for three successive generations, the significantly enhanced resistance to take-all was observed in the three TiMYB2R-1-overexpressing transgenic wheat lines. Furthermore, the transcript levels of at least six wheat defence-related genes were significantly elevated in the TiMYB2R-1 transgenic wheat lines. These results suggest that engineering and overexpression of TiMYB2R-1 may be used for improving take-all resistance of wheat and other cereal crops.

  7. Antimicrobial resistance

    DEFF Research Database (Denmark)

    Llor, Carl; Bjerrum, Lars

    2014-01-01

    Antimicrobial resistance is a global public health challenge, which has accelerated by the overuse of antibiotics worldwide. Increased antimicrobial resistance is the cause of severe infections, complications, longer hospital stays and increased mortality. Overprescribing of antibiotics......-the-counter sale of antibiotics, the use of antimicrobial stewardship programmes, the active participation of clinicians in audits, the utilization of valid rapid point-of-care tests, the promotion of delayed antibiotic prescribing strategies, the enhancement of communication skills with patients with the aid...

  8. Enhanced Electrical Resistivity after Rapid Cool of the Specimen in Layered Oxide LixCoO2

    Science.gov (United States)

    Miyoshi, K.; Manami, K.; Takeuchi, J.; Sasai, R.; Nishigori, S.

    Measurements of electrical resistivity and DC magnetization for LixCoO2 (x=0.71 and 0.64) have been performed using single crystal specimens. It has been found that electrical resistivity measured after rapid cool of the specimen becomes larger compared with that after slow cool below the temperature TS∽155 K at which charge ordering of Co3+/Co4+(=2:1) occurs. The behavior can be understood considering that the charge ordering can be destroyed by Li ions which are in an amorphous state after rapid cool via the interlayer Coulomb interactions, and also that the disordered Co3+/Co4+ state becomes insulating, while the charge ordered state has a metallic electronic structure, as recently revealed by the scanning tunneling microscopy.

  9. Fate of antibiotic resistance bacteria and genes during enhanced anaerobic digestion of sewage sludge by microwave pretreatment.

    Science.gov (United States)

    Tong, Juan; Liu, Jibao; Zheng, Xiang; Zhang, Junya; Ni, Xiaotang; Chen, Meixue; Wei, Yuansong

    2016-10-01

    The fate of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) were investigated during the sludge anaerobic digestion (AD) with microwave-acid (MW-H), microwave (MW) and microwave-H2O2-alkaline (MW-H2O2) pretreatments. Results showed that combined MW pretreatment especially for the MW-H pretreatment could efficiently reduce the ARB concentration, and most ARG concentrations tended to attenuate during the pretreatment. The subsequent AD showed evident removal of the ARB, but most ARGs were enriched after AD. Only the concentration of tetX kept continuous declination during the whole sludge treatment. The total ARGs concentration showed significant correlation with 16S rRNA during the pretreatment and AD. Compared with unpretreated sludge, the AD of MW and MW-H2O2 pretreated sludge presented slightly better ARB and ARGs reduction efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Pest and disease resistance enhanced by heterologous suppression of a Nicotiana plumbaginifolia cytochrome P450 gene CYP72A2.

    Science.gov (United States)

    Smigocki, Ann C; Wilson, Dennis

    2004-12-01

    The functional role of the Nicotiana plumbaginifolia cytochrome P450 gene CYP72A2 was investigated in transgenic plants. N. tabacum plants transformed with a sense or antisense CYP72A2 construct exhibited diminished heights, branched stems, smaller leaves and deformed flowers. Western blot analysis revealed reduced levels of a 58 kDa protein corresponding to CYP72A2, suggesting that the CYP72A2 homolog was suppressed in the sense and antisense plants. Transgenic plants had increased resistance to Manduca sexta larvae that consumed about 35 to 90 less of transgenic versus control leaves. A virulent strain of Pseudomonas syringae pv. tabaci induced a disease-limiting response followed by a delayed and decreased development of disease symptoms in the transgenics. CYP72A2 gene mediated resistance suggests that the plant-pest or -pathogen interactions may have been modified by changes in bioactive metabolite pools.

  11. Hierarchical Control with Virtual Resistance Optimization for Efficiency Enhancement and State-of-Charge Balancing in DC Microgrids

    DEFF Research Database (Denmark)

    Meng, Lexuan; Dragicevic, Tomislav; Quintero, Juan Carlos Vasquez

    2015-01-01

    This paper proposes a hierarchical control scheme which applies optimization method into DC microgrids in order to improve the system overall efficiency while considering the State-of-Charge (SoC) balancing at the same time. Primary droop controller, secondary voltage restoration controller...... and tertiary optimization tool formulate the complete hierarchical control system. Virtual resistances are taken as the decision variables for achieving the objective. simulation results are presented to verify the proposed approach....

  12. Improvement of the fungal biocontrol agent Trichoderma atroviride to enhance both antagonism and induction of plant systemic disease resistance.

    Science.gov (United States)

    Brunner, Kurt; Zeilinger, Susanne; Ciliento, Rosalia; Woo, Sheridian L; Lorito, Matteo; Kubicek, Christian P; Mach, Robert L

    2005-07-01

    Biocontrol agents generally do not perform well enough under field conditions to compete with chemical fungicides. We determined whether transgenic strain SJ3-4 of Trichoderma atroviride, which expresses the Aspergillus niger glucose oxidase-encoding gene, goxA, under a homologous chitinase (nag1) promoter had increased capabilities as a fungal biocontrol agent. The transgenic strain differed only slightly from the wild-type in sporulation or the growth rate. goxA expression occurred immediately after contact with the plant pathogen, and the glucose oxidase formed was secreted. SJ3-4 had significantly less N-acetylglucosaminidase and endochitinase activities than its nontransformed parent. Glucose oxidase-containing culture filtrates exhibited threefold-greater inhibition of germination of spores of Botrytis cinerea. The transgenic strain also more quickly overgrew and lysed the plant pathogens Rhizoctonia solani and Pythium ultimum. In planta, SJ3-4 had no detectable improved effect against low inoculum levels of these pathogens. Beans planted in heavily infested soil and treated with conidia of the transgenic Trichoderma strain germinated, but beans treated with wild-type spores did not germinate. SJ3-4 also was more effective in inducing systemic resistance in plants. Beans with SJ3-4 root protection were highly resistant to leaf lesions caused by the foliar pathogen B. cinerea. This work demonstrates that heterologous genes driven by pathogen-inducible promoters can increase the biocontrol and systemic resistance-inducing properties of fungal biocontrol agents, such as Trichoderma spp., and that these microbes can be used as vectors to provide plants with useful molecules (e.g., glucose oxidase) that can increase their resistance to pathogens.

  13. Elevated Mcl-1 perturbs lymphopoiesis, promotes transformation of hematopoietic stem/progenitor cells, and enhances drug resistance

    OpenAIRE

    Campbell, Kirsteen J.; Bath, Mary L.; Turner, Marian L.; Vandenberg, Cassandra J.; Bouillet, Philippe; Metcalf, Donald; Scott, Clare L.; Cory, Suzanne

    2010-01-01

    Diverse human cancers with poor prognosis, including many lymphoid and myeloid malignancies, exhibit high levels of Mcl-1. To explore the impact of Mcl-1 overexpression on the hematopoietic compartment, we have generated vavP-Mcl-1 transgenic mice. Their lymphoid and myeloid cells displayed increased resistance to a variety of cytotoxic agents. Myelopoiesis was relatively normal, but lymphopoiesis was clearly perturbed, with excess mature B and T cells accumulating. Rather than the follicular...

  14. Compressive Residual Strains in Mineral Nanoparticles as a Possible Origin of Enhanced Crack Resistance in Human Tooth Dentin.

    Science.gov (United States)

    Forien, Jean-Baptiste; Fleck, Claudia; Cloetens, Peter; Duda, Georg; Fratzl, Peter; Zolotoyabko, Emil; Zaslansky, Paul

    2015-06-10

    The tough bulk of dentin in teeth supports enamel, creating cutting and grinding biostructures with superior failure resistance that is not fully understood. Synchrotron-based diffraction methods, utilizing micro- and nanofocused X-ray beams, reveal that the nm-sized mineral particles aligned with collagen are precompressed and that the residual strains vanish upon mild annealing. We show the link between the mineral nanoparticles and known damage propagation trajectories in dentin, suggesting a previously overlooked compression-mediated toughening mechanism.

  15. Fracture Network and Fluid Flow Imaging for Enhanced Geothermal Systems Applications from Multi-Dimensional Electrical Resistivity Structure

    Energy Technology Data Exchange (ETDEWEB)

    Wannamaker, Philip E. [Univ. of Utah, Salt Lake City, UT (United States)

    2016-03-26

    We have developed an algorithm for the inversion of magnetotelluric (MT) data to a 3D earth resistivity model based upon the finite element method. Hexahedral edge finite elements are implemented to accommodate discontinuities in the electric field across resistivity boundaries, and to accurately simulate topographic variations. All matrices are reduced and solved using direct solution modules which avoids ill-conditioning endemic to iterative solvers such as conjugate gradients, principally PARDISO for the finite element system and PLASMA for the parameter step estimate. Large model parameterizations can be handled by transforming the Gauss-Newton estimator to data-space form. Accuracy of the forward problem and jacobians has been checked by comparison to integral equations results and by limiting asymptotes. Inverse accuracy and performance has been verified against the public Dublin Secret Test Model 2 and the well-known Mount St Helens 3D MT data set. This algorithm we believe is the most capable yet for forming 3D images of earth resistivity structure and their implications for geothermal fluids and pathways.

  16. Attaching the NorA Efflux Pump Inhibitor INF55 to Methylene Blue Enhances Antimicrobial Photodynamic Inactivation of Methicillin-Resistant Staphylococcus aureus in Vitro and in Vivo.

    Science.gov (United States)

    Rineh, Ardeshir; Dolla, Naveen K; Ball, Anthony R; Magana, Maria; Bremner, John B; Hamblin, Michael R; Tegos, George P; Kelso, Michael J

    2017-10-13

    Antimicrobial photodynamic inactivation (aPDI) uses photosensitizers (PSs) and harmless visible light to generate reactive oxygen species (ROS) and kill microbes. Multidrug efflux systems can moderate the phototoxic effects of PSs by expelling the compounds from cells. We hypothesized that increasing intracellular concentrations of PSs by inhibiting efflux with a covalently attached efflux pump inhibitor (EPI) would enhance bacterial cell phototoxicity and reduce exposure of neighboring host cells to damaging ROS. In this study, we tested the hypothesis by linking NorA EPIs to methylene blue (MB) and examining the photoantimicrobial activity of the EPI-MB hybrids against the human pathogen methicillin-resistant Staphylococcus aureus (MRSA). Photochemical/photophysical and in vitro microbiological evaluation of 16 hybrids carrying four different NorA EPIs attached to MB via four linker types identified INF55-(Ac)en-MB 12 as a lead. Compound 12 showed increased uptake into S. aureus cells and enhanced aPDI activity and wound healing effects (relative to MB) in a murine model of an abrasion wound infected by MRSA. The study supports a new approach for treating localized multidrug-resistant MRSA infections and paves the way for wider exploration of the EPI-PS hybrid strategy in aPDI.

  17. Morphologic and Chemical Properties of PMMA/ATH Layers with Enhanced Abrasion Resistance Realised by Cold Plasma Spraying at Atmospheric Pressure

    Directory of Open Access Journals (Sweden)

    L. Wallenhorst

    2018-01-01

    Full Text Available This study investigated the morphologic and chemical properties of coatings based on PMMA/ATH powder and deposited by cold plasma spraying on wood and glass. Since the deposition of pure PMMA/ATH powder with air as process gas yielded coatings with insufficient abrasion resistance, two modifications of the basic process were investigated. Previous studies showed that replacing air as process gas with forming gas did not enhance the abrasion resistance, but the addition of a phenol-formaldehyde resin (PF succeeded in stabilising the particle coatings. In this work, results from morphologic and chemical analysis suggested an encasement of the PMMA/ATH particles by plasma-modified PF and thus a fusion of individual particles, explaining the enhanced bonding. Moreover, adhesion tests confirmed an outstanding bonding between the coating and wood as well as glass, which is assumed to result from interactions between the PF’s hydroxyl groups and functional groups on the substrates’ surfaces. Studies on the wettability revealed a hydrophobic character of such coatings, therefore generally indicating a possible application, for example, to reduce water uptake by wooden materials.

  18. Pre-Treatment of Platinum Resistant Ovarian Cancer Cells with an MMP-9/MMP-2 Inhibitor Prior to Cisplatin Enhances Cytotoxicity as Determined by High Content Screening

    Directory of Open Access Journals (Sweden)

    John J. O'Leary

    2013-01-01

    Full Text Available Platinum resistance is a major cause of treatment failure in ovarian cancer. We previously identified matrix metalloproteinase 9 (MMP-9 as a potential therapeutic target of chemoresistant disease. A2780cis (cisplatin-resistant and A2780 (cisplatin-sensitive ovarian carcinoma cell lines were used. The cytotoxic effect of MMP-9/MMP-2 inhibitor, (2R-2-[(4-Biphenylsulfonyl amino]-3 phenylpropionic acid (C21H19NO4S alone or in combination with cisplatin was determined using high content screening. Protein expression was examined using immunohistochemistry and ELISA. Co-incubation of cisplatin and an MMP-9/MMP-2 inhibitor, (2R-2-[(4-Biphenylsulfonyl amino]-3 phenylpropionic acid (C21H19NO4S resulted in significantly greater cytotoxicity as compared to either treatment alone in a cisplatin resistant MMP-9 overexpressing cell line; A2780cis. In addition, pre-incubating with MMP-9i prior to cisplatin further enhances the cytotoxic effect. No significant difference was observed in MMP-9 protein in tissue but a trend towards increased MMP-9 was observed in recurrent serum. We propose that MMP-9/MMP-2i may be utilized in the treatment of recurrent/chemoresistant ovarian cancers that overexpress MMP-9 mRNA but its role in vivo remains to be evaluated.

  19. Comparing the performance-enhancing effects of squats on a vibration platform with conventional squats in recreationally resistance-trained men.

    Science.gov (United States)

    Rønnestad, Bent R

    2004-11-01

    The purpose of this investigation was to compare the performance-enhancing effects of squats on a vibration platform with conventional squats in recreationally resistance-trained men. The subjects were 14 recreationally resistance-trained men (age, 21-40 years) and the intervention period consisted of 5 weeks. After the initial testing, subjects were randomly assigned to either the "squat whole body vibration" (SWBV) group (n = 7), which performed squats on a vibration platform on a Smith Machine, or the "squat"(S) group (n = 7), which performed conventional squats with no vibrations on a Smith Machine. Testing was performed at the beginning and the end of the study and consisted of 1 repetition maximum (1RM) in squat and maximum jump height in countermovement jump (CMJ). A modified daily undulating periodization program was used during the intervention period in both groups. Both groups trained at the same percentage of 1RM in squats (6-10RM). After the intervention, CMJ performance increased significantly only in the SWBV (p squats (p squats performed on a vibration platform compared with squats without vibrations regarding maximal strength and explosive power as long as the external load is similar in recreationally resistance-trained men.

  20. Harnessing Diversity in Wheat to Enhance Grain Yield, Climate Resilience, Disease and Insect Pest Resistance and Nutrition Through Conventional and Modern Breeding Approaches

    Science.gov (United States)

    Mondal, Suchismita; Rutkoski, Jessica E.; Velu, Govindan; Singh, Pawan K.; Crespo-Herrera, Leonardo A.; Guzmán, Carlos; Bhavani, Sridhar; Lan, Caixia; He, Xinyao; Singh, Ravi P.

    2016-01-01

    Current trends in population growth and consumption patterns continue to increase the demand for wheat, a key cereal for global food security. Further, multiple abiotic challenges due to climate change and evolving pathogen and pests pose a major concern for increasing wheat production globally. Triticeae species comprising of primary, secondary, and tertiary gene pools represent a rich source of genetic diversity in wheat. The conventional breeding strategies of direct hybridization, backcrossing and selection have successfully introgressed a number of desirable traits associated with grain yield, adaptation to abiotic stresses, disease resistance, and bio-fortification of wheat varieties. However, it is time consuming to incorporate genes conferring tolerance/resistance to multiple stresses in a single wheat variety by conventional approaches due to limitations in screening methods and the lower probabilities of combining desirable alleles. Efforts on developing innovative breeding strategies, novel tools and utilizing genetic diversity for new genes/alleles are essential to improve productivity, reduce vulnerability to diseases and pests and enhance nutritional quality. New technologies of high-throughput phenotyping, genome sequencing and genomic selection are promising approaches to maximize progeny screening and selection to accelerate the genetic gains in breeding more productive varieties. Use of cisgenic techniques to transfer beneficial alleles and their combinations within related species also offer great promise especially to achieve durable rust resistance. PMID:27458472

  1. Cr-resistant rhizo- and endophytic bacteria associated with Prosopis juliflora and their potential as phytoremediation enhancing agents in metal-degraded soils

    Directory of Open Access Journals (Sweden)

    Muhammad Umar Khan

    2015-01-01

    Full Text Available Prosopis juliflora is characterized by distinct and profuse growth even in nutritionally poor soil and environmentally stressed conditions and is believed to harbor some novel heavy metal-resistant bacteria in the rhizosphere and endosphere. This study was performed to isolate and characterize Cr-resistant bacteria from the rhizosphere and endosphere of P. juliflora growing on the tannery effluent contaminated soil. A total of 5 and 21 bacterial strains were isolated from the rhizosphere and endosphere, respectively, could tolerate Cr up to 3000 mg l-1. These isolates also exhibited tolerance to other toxic heavy metals such as, Cd, Cu, Pb and Zn, and high concentration (174 g l-1 of NaCl. Moreover, most of the isolated bacterial strains showed one or more plant growth-promoting activities. The phylogenetic analysis of the 16S rRNA gene indicated a higher and wider range of population of Cr-resistant bacteria in the endosphere than rhizosphere and the predominant species included Bacillus, Staphylococcus and Aerococcus. As far as we know, this is the first report detecting rhizo- and endophytic bacterial population associated with P. juliflora growing on the tannery effluent contaminated soil. The inoculation of three isolates to ryegrass (Lolium multiflorum L. improved plant growth and heavy metal removal from the tannery effluent contaminated soil suggesting that these bacteria could enhance the establishment of the plant in contaminated soil and also improve the efficiency of phytoremediation of heavy metal-degraded soils.

  2. SPIN1, negatively regulated by miR-148/152, enhances Adriamycin resistance via upregulating drug metabolizing enzymes and transporter in breast cancer.

    Science.gov (United States)

    Chen, Xu; Wang, Ya-Wen; Gao, Peng

    2018-05-09

    Spindlin1 (SPIN1), a protein highly expressed in several human cancers, has been correlated with tumorigenesis and development. Alterations of drug metabolizing enzymes and drug transporters are major determinants of chemoresistance in tumor cells. However, whether the metabolizing enzymes and transporters are under the control of SPIN1 in breast cancer chemoresistance has not yet been defined. SPIN1 expression in breast cancer cells and tissues was detected by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. Chemosensitivity assays in vitro and in vivo were performed to determine the effect of SPIN1 on Adriamycin resistance. Downstream effectors of SPIN1 were screened by microarray and confirmed by qRT-PCR and Western blot. Luciferase assay and Western blot were used to identify miRNAs regulating SPIN1. We showed that SPIN1 was significantly elevated in drug-resistant breast cancer cell lines and tissues, compared with the chemosensitive ones. SPIN1 enhanced Adriamycin resistance of breast cancer cells in vitro, and downregulation of SPIN1 by miRNA could decrease Adriamycin resistance in vivo. Mechanistically, drug metabolizing enzymes and transporter CYP2C8, UGT2B4, UGT2B17 and ABCB4 were proven to be downstream effectors of SPIN1. Notably, SPIN1 was identified as a direct target of the miR-148/152 family (miR-148a-3p, miR-148b-3p and miR-152-3p). As expected, miR-148a-3p, miR-148b-3p or miR-152-3p could increase Adriamycin sensitivity in breast cancer cells in vitro. Moreover, high expression of SPIN1 or low expression of the miR-148/152 family predicted poorer survival in breast cancer patients. Our results establish that SPIN1, negatively regulated by the miR-148/152 family, enhances Adriamycin resistance in breast cancer via upregulating the expression of drug metabolizing enzymes and drug transporter.

  3. Comparative proteomic and metabolomic profiling of citrus fruit with enhancement of disease resistance by postharvest heat treatment.

    Science.gov (United States)

    Yun, Ze; Gao, Huijun; Liu, Ping; Liu, Shuzhen; Luo, Tao; Jin, Shuai; Xu, Qiang; Xu, Juan; Cheng, Yunjiang; Deng, Xiuxin

    2013-03-16

    From field harvest to the consumer's table, fresh citrus fruit spends a considerable amount of time in shipment and storage. During these processes, physiological disorders and pathological diseases are the main causes of fruit loss. Heat treatment (HT) has been widely used to maintain fruit quality during postharvest storage; however, limited molecular information related to this treatment is currently available at a systemic biological level. Mature 'Kamei' Satsuma mandarin (Citrus unshiu Marc.) fruits were selected for exploring the disease resistance mechanisms induced by HT during postharvest storage. Proteomic analyses based on two-dimensional gel electrophoresis (2-DE), and metabolomic research based on gas chromatography coupled to mass spectrometry (GC-MS), and liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QToF-MS) were conducted. The results show resistance associated proteins were up-regulated in heat treated pericarp, such as beta-1, 3-glucanase, Class III chitinase, 17.7 kDa heat shock protein and low molecular weight heat-shock protein. Also, redox metabolism enzymes were down-regulated in heat treated pericarp, including isoflavone reductase, oxidoreductase and superoxide dismutase. Primary metabolic profiling revealed organic acids and amino acids were down-regulated in heat treated pericarp; but significant accumulation of metabolites, including tetradecanoic acid, oleic acid, ornithine, 2-keto-d-gluconic acid, succinic acid, turanose, sucrose, galactose, myo-inositol, glucose and fructose were detected. Noticeably, H2O2 content decreased, while, lignin content increased in heat treated pericarp compared to the control, which might increase fruit resistibility in response to external stress. Also, flavonoids, substances which are well-known to be effective in reducing external stress, were up-regulated in heat treated pericarp. This study provides a broad picture of differential accumulation of proteins and metabolites in

  4. Androgen receptor (AR) degradation enhancer ASC-J9® in an FDA-approved formulated solution suppresses castration resistant prostate cancer cell growth.

    Science.gov (United States)

    Cheng, Max A; Chou, Fu-Ju; Wang, Keliang; Yang, Rachel; Ding, Jie; Zhang, Qiaoxia; Li, Gonghui; Yeh, Shuyuan; Xu, Defeng; Chang, Chawnshang

    2018-03-28

    ASC-J9 ® is a recently-developed androgen receptor (AR)-degradation enhancer that effectively suppresses castration resistant prostate cancer (PCa) cell proliferation and invasion. The optimal half maximum inhibitory concentrations (IC 50 ) of ASC-J9 ® at various PCa cell confluences (20%, 50%, and 100%) were assessed via both short-term MTT growth assays and long-term clonogenic proliferation assays. Our results indicate that the IC 50 values for ASC-J9 ® increased with increasing cell confluency. The IC 50 values were significantly decreased in PCa AR-positive cells compared to PCa AR-negative cells or in normal prostate cells. This suggests that ASC-J9 ® may function mainly via targeting the AR-positive PCa cells with limited unwanted side-effects to suppress the surrounding normal prostate cells. Mechanism dissection indicated that ASC-J9 ® might function via altering the apoptosis signals to suppress the PCa AR-negative PC-3 cells. Preclinical studies using multiple in vitro PCa cell lines and an in vivo mouse model with xenografted castration-resistant PCa CWR22Rv1 cells demonstrated that ASC-J9 ® has similar AR degradation effects when dissolved in FDA-approved solvents, including DMSO, PEG-400:Tween-80 (95:5), DMA:Labrasol:Tween-80 (10:45:45), and DMA:Labrasol:Tween-20 (10:45:45). Together, results from preclinical studies suggest a potential new therapy with AR-degradation enhancer ASC-J9 ® may potentially be ready to be used in human clinical trials in order to better suppress PCa at later castration resistant stages. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Green tissue-specific co-expression of chitinase and oxalate oxidase 4 genes in rice for enhanced resistance against sheath blight.

    Science.gov (United States)

    Karmakar, Subhasis; Molla, Kutubuddin Ali; Chanda, Palas K; Sarkar, Sailendra Nath; Datta, Swapan K; Datta, Karabi

    2016-01-01

    Green tissue-specific simultaneous overexpression of two defense-related genes ( OsCHI11 & OsOXO4 ) in rice leads to significant resistance against sheath blight pathogen ( R. solani ) without distressing any agronomically important traits. Overexpressing two defense-related genes (OsOXO4 and OsCHI11) cloned from rice is effective at enhancing resistance against sheath blight caused by Rhizoctonia solani. These genes were expressed under the control of two different green tissue-specific promoters, viz. maize phosphoenolpyruvate carboxylase gene promoter, PEPC, and rice cis-acting 544-bp DNA element, immediately upstream of the D54O translational start site, P D54O-544 . Putative T0 transgenic rice plants were screened by PCR and integration of genes was confirmed by Southern hybridization of progeny (T1) rice plants. Successful expression of OsOXO4 and OsCHI11 in all tested plants was confirmed. Expression of PR genes increased significantly following pathogen infection in overexpressing transgenic plants. Following infection, transgenic plants exhibited elevated hydrogen peroxide levels, significant changes in activity of ROS scavenging enzymes and reduced membrane damage when compared to their wild-type counterpart. In a Rhizoctonia solani toxin assay, a detached leaf inoculation test and an in vivo plant bioassay, transgenic plants showed a significant reduction in disease symptoms in comparison to non-transgenic control plants. This is the first report of overexpression of two different PR genes driven by two green tissue-specific promoters providing enhanced sheath blight resistance in transgenic rice.

  6. Evaluation of macrolide resistance and enhanced molecular typing of Treponema pallidum in patients with syphilis in Taiwan: a prospective multicenter study.

    Science.gov (United States)

    Wu, Hsiu; Chang, Sui-Yuan; Lee, Nan-Yao; Huang, Wen-Chi; Wu, Bing-Ru; Yang, Chia-Jui; Liang, Shiou-Haur; Lee, Chen-Hsiang; Ko, Wen-Chien; Lin, Hsi-Hsun; Chen, Yen-Hsu; Liu, Wen-Chun; Su, Yi-Ching; Hsieh, Chia-Yin; Wu, Pei-Ying; Hung, Chien-Ching

    2012-07-01

    Studies of macrolide resistance mutations and molecular typing using the newly proposed enhanced typing system for Treponema pallidum isolates obtained from HIV-infected patients in the Asia-Pacific region are scarce. Between September 2009 and December 2011, we conducted a survey to detect T. pallidum using a PCR assay using clinical specimens from patients with syphilis at six major designated hospitals for HIV care in Taiwan. The T. pallidum strains were genotyped by following the enhanced molecular typing methodology, which analyzed the number of 60-bp repeats in the acidic repeat protein (arp) gene, T. pallidum repeat (tpr) polymorphism, and the sequence of base pairs 131 to 215 in the tp0548 open reading frame of T. pallidum. Detection of A2058G and A2059G point mutations in the T. pallidum 23S rRNA was performed with the use of restriction fragment length polymorphism (RFLP). During the 2-year study period, 211 clinical specimens were obtained from 136 patients with syphilis. T. pallidum DNA was isolated from 105 (49.8%) of the specimens, with swab specimens obtained from chancres having the highest yield rate (63.2%), followed by plasma (49.4%), serum (35.7%), and cerebrospinal fluid or vitreous fluid (18.2%) specimens. Among the 40 fully typed specimens, 11 subtypes of T. pallidum were identified. Subtype 14f/f (18 isolates) was the most common isolates, followed by 14f/c (3), 14b/c (3), and 14k/f (3). Among the isolates examined for macrolide resistance, none had the A2058G or A2059G mutation. In conclusion, we found that type 14 f/f was the most common T. pallidum strain in this multicenter study on syphilis in Taiwan and that none of the isolates exhibited 23S rRNA mutations causing resistance to macrolides.

  7. Enhanced Botrytis cinerea resistance of Arabidopsis plants grown in compost may be explained by increased expression of defense-related genes, as revealed by microarray analysis.

    Directory of Open Access Journals (Sweden)

    Guillem Segarra

    Full Text Available Composts are the products obtained after the aerobic degradation of different types of organic matter waste and can be used as substrates or substrate/soil amendments for plant cultivation. There is a small but increasing number of reports that suggest that foliar diseases may be reduced when using compost, rather than standard substrates, as growing medium. The purpose of this study was to examine the gene expression alteration produced by the compost to gain knowledge of the mechanisms involved in compost-induced systemic resistance. A compost from olive marc and olive tree leaves was able to induce resistance against Botrytis cinerea in Arabidopsis, unlike the standard substrate, perlite. Microarray analyses revealed that 178 genes were differently expressed, with a fold change cut-off of 1, of which 155 were up-regulated and 23 were down-regulated in compost-grown, as against perlite-grown plants. A functional enrichment study of up-regulated genes revealed that 38 Gene Ontology terms were significantly enriched. Response to stress, biotic stimulus, other organism, bacterium, fungus, chemical and abiotic stimulus, SA and ABA stimulus, oxidative stress, water, temperature and cold were significantly enriched, as were immune and defense responses, systemic acquired resistance, secondary metabolic process and oxireductase activity. Interestingly, PR1 expression, which was equally enhanced by growing the plants in compost and by B. cinerea inoculation, was further boosted in compost-grown pathogen-inoculated plants. Compost triggered a plant response that shares similarities with both systemic acquired resistance and ABA-dependent/independent abiotic stress responses.

  8. Resistance to quinclorac caused by the enhanced ability to detoxify cyanide and its molecular mechanism in Echinochloa crus-galli var. zelayensis.

    Science.gov (United States)

    Gao, Yuan; Pan, Lang; Sun, Yu; Zhang, Teng; Dong, Liyao; Li, Jun

    2017-11-01

    Quinclorac, an auxin-type herbicide, is widely used to control barnyardgrass and some dicotyledon weeds. Echinochloa crus-galli var. zelayensis, a variety of E. crus-galli (L.) Beauv., is widespread in China and some populations have resistance to quinclorac. E. crus-galli var. zelayensis seeds with varying sensitivity to quinclorac were used in the present study. The expression of the ADP/ATP carrier protein (ANT) gene, which plays an important role in the maintenance of cellular energy balance, dramatically rose in the S biotype after exposure to quinclorac, while no change was found in two R biotypes. The activity of β-cyanoalanine synthase (β-CAS), which is the key enzyme for cyanide degradation, was higher in two R biotypes than in the S biotype before and after treatment with quinclorac. One single-nucleotide difference was detected in the EcCAS gene of two R biotypes compared with the S biotype. The nucleotide change, which caused one amino acid substitution, replacing Methionine (Met)-295 with Lysine (Lys)-295 in the two R biotypes, which are same as the rice β-CAS gene at this position. In addition, EcCAS gene expression was higher in the two R biotypes than in the S biotype. In conclusion, β-CAS may play a crucial role in the resistance of E. crus-galli var. zelayensis to quinclorac. EcCAS gene mutation and higher gene expression may enhance the activity of β-CAS to avoid the accumulation of toxic cyanide in resistant populations, thus contributing to the resistance mechanism of E. crus-galli var. zelayensis. to quinclorac. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Suppression of the auxin response pathway enhances susceptibility to Phytophthora cinnamomi while phosphite-mediated resistance stimulates the auxin signalling pathway

    Science.gov (United States)

    2014-01-01

    Background Phytophthora cinnamomi is a devastating pathogen worldwide and phosphite (Phi), an analogue of phosphate (Pi) is highly effective in the control of this pathogen. Phi also interferes with Pi starvation responses (PSR), of which auxin signalling is an integral component. In the current study, the involvement of Pi and the auxin signalling pathways in host and Phi-mediated resistance to P. cinnamomi was investigated by screening the Arabidopsis thaliana ecotype Col-0 and several mutants defective in PSR and the auxin response pathway for their susceptibility to this pathogen. The response to Phi treatment was also studied by monitoring its effect on Pi- and the auxin response pathways. Results Here we demonstrate that phr1-1 (phosphate starvation response 1), a mutant defective in response to Pi starvation was highly susceptible to P. cinnamomi compared to the parental background Col-0. Furthermore, the analysis of the Arabidopsis tir1-1 (transport inhibitor response 1) mutant, deficient in the auxin-stimulated SCF (Skp1 − Cullin − F-Box) ubiquitination pathway was also highly susceptible to P. cinnamomi and the susceptibility of the mutants rpn10 and pbe1 further supported a role for the 26S proteasome in resistance to P. cinnamomi. The role of auxin was also supported by a significant (P < 0.001) increase in susceptibility of blue lupin (Lupinus angustifolius) to P. cinnamomi following treatment with the inhibitor of auxin transport, TIBA (2,3,5-triiodobenzoic acid). Given the apparent involvement of auxin and PSR signalling in the resistance to P. cinnamomi, the possible involvement of these pathways in Phi mediated resistance was also investigated. Phi (especially at high concentrations) attenuates the response of some Pi starvation inducible genes such as AT4, AtACP5 and AtPT2 in Pi starved plants. However, Phi enhanced the transcript levels of PHR1 and the auxin responsive genes (AUX1, AXR1and AXR2), suppressed the primary root

  10. Moss Pathogenesis-Related-10 protein enhances resistance to Pythium irregulare in Physcomitrella patens and Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Alexandra eCastro

    2016-04-01

    Full Text Available Plants respond to pathogen infection by activating signaling pathways leading to the accumulation of proteins with diverse roles in defense. Here, we addressed the functional role of PpPR-10, a pathogenesis-related (PR-10 gene, of the moss Physcomitrella patens, in response to biotic stress. PpPR-10 belongs to a multigene family and encodes a protein twice the usual size of PR-10 proteins due to the presence of two Bet v1 domains. Moss PR-10 genes are differentially regulated during development and inoculation with the fungal pathogen Botrytis cinerea. Specifically, PpPR-10 transcript levels increase significantly by treatments with elicitors of Pectobacterium carotovorum subsp. carotovorum, spores of B. cinerea, and the defense hormone salicylic acid. To characterize the role of PpPR-10 in plant defense against pathogens, we conducted overexpression analysis in P. patens and in Arabidopsis thaliana. We demonstrate that constitutive expression of PpPR-10 in moss tissues increased resistance against the oomycete Pythium irregulare. PpPR-10 overexpressing moss plants developed less symptoms and decreased mycelium growth than wild type plants. In addition, PpPR-10 overexpressing plants constitutively produced cell wall depositions in protonemal tissue. Ectopic expression of PpPR-10 in Arabidopsis resulted in increased resistance against P. irregulare as well, evidenced by smaller lesions and less cellular damage compared to wild type plants. These results indicate that PpPR-10 is functionally active in the defense against the pathogen P. irregulare, in both P. patens and Arabidopsis, two evolutionary distant plants. Thus, P. patens can serve as an interesting source of genes to improve resistance against pathogen infection in flowering plants.

  11. Knockdown of UbcH10 Enhances the Chemosensitivity of Dual Drug Resistant Breast Cancer Cells to Epirubicin and Docetaxel

    Directory of Open Access Journals (Sweden)

    Cheng Wang

    2015-03-01

    Full Text Available Breast cancer is one of the most common and lethal cancers in women. As a hub gene involved in a diversity of tumors, the ubiquitin-conjugating enzyme H10 (UbcH10, may also play some roles in the genesis and development of breast cancer. In the current study, we found that the expression of UbcH10 was up-regulated in some breast cancer tissues and five cell lines. We established a dual drug resistant cell line MCF-7/EPB (epirubicin/TXT (docetaxel and a lentiviral system expressing UbcH10 shRNA to investigate the effects of UbcH10 knockdown on the chemosensitivity of MCF-7/EPB/TXT cells to epirubicin and docetaxel. The knockdown of UbcH10 inhibited the proliferation of both MCF-7 and MCF-7/EPB/TXT cells, due to the G1 phase arrest in cell cycle. Furthermore, UbcH10 knockdown increased the sensitivity of MCF-7/EPB/TXT cells to epirubicin and docetaxel and promoted the apoptosis induced by these two drugs. Protein detection showed that, in addition to inhibiting the expression of Ki67 and cyclin D1, UbcH10 RNAi also impaired the increased BCL-2 and MDR-1 expression levels in MCF-7/EPB/TXT cells, which may contribute to abating the drug resistance in the breast cancer cells. Our research in the current study demonstrated that up-regulation of UbcH10 was involved in breast cancer and its knockdown can inhibit the growth of cancer cells and increase the chemosensitivity of the dual drug resistant breast cancer cells to epirubicin and docetaxel, suggesting that UbcH10 may be a promising target for the therapy of breast cancer.

  12. One-pot synthesis of reduced graphene oxide@boron nitride nanosheet hybrids with enhanced oxidation-resistant properties

    Science.gov (United States)

    Sun, Guoxun; Bi, Jianqiang; Wang, Weili; Zhang, Jingde

    2017-12-01

    Reduced graphene oxide@boron nitride nanosheet (RGO@BNNS) hybrids were prepared for the first time using template-assisted autoclave pyrolysis technique at the temperature as low as 600 °C. The developed method can be scaled into gram-scale synthesis of the material. The BNNSs combine with RGO through van der Waals interplanar interaction without damaging the structures of RGO. Such ultrathin BNNSs on the surface of RGO can serve as high-performance oxidation-resistant coatings in oxidizing atmospheres at high temperatures. The RGO@BNNS hybrids can sustain up to 800 °C over a relatively long period of time.

  13. Hybrid poly(lactic acid)/nanocellulose/nanoclay composites with synergistically enhanced barrier properties and improved thermomechanical resistance

    DEFF Research Database (Denmark)

    Trifol Guzman, Jon; Plackett, David; Sillard, Cecile

    2016-01-01

    Poly(lactic acid) (PLA)‐based hybrid nanocomposites (PLA, nanoclay and nanocellulose) were prepared by reinforcing neat PLA with commercially available nanoclay (Cloisite C30B) and nanocellulose, in the form of either partially acetylated cellulose nanofibres (CNFs) or nanocrystalline cellulose......) through a reduction of up to 90% in OTR and a further reduction in the water vapour transmission rate of up to 76%. In addition, the nanocomposite films showed improved thermomechanical resistance and improved crystallisation kinetics while maintaining high film transparency. This makes the hybrid PLA...

  14. The Vibrio cholerae Mrp system: cation/proton antiport properties and enhancement of bile salt resistance in a heterologous host.

    Science.gov (United States)

    Dzioba-Winogrodzki, Judith; Winogrodzki, Olga; Krulwich, Terry A; Boin, Markus A; Häse, Claudia C; Dibrov, Pavel

    2009-01-01

    The mrp operon from Vibrio cholerae encoding a putative multisubunit Na(+)/H(+) antiporter was cloned and functionally expressed in the antiporter-deficient strain of Escherichia coli EP432. Cells of EP432 expressing Vc-Mrp exhibited resistance to Na(+) and Li(+) as well as to natural bile salts such as sodium cholate and taurocholate. When assayed in everted membrane vesicles of the E. coli EP432 host, Vc-Mrp had sufficiently high antiport activity to facilitate the first extensive analysis of Mrp system from a Gram-negative bacterium encoded by a group 2 mrp operon. Vc-Mrp was found to exchange protons for Li(+), Na(+), and K(+) ions in pH-dependent manner with maximal activity at pH 9.0-9.5. Exchange was electrogenic (more than one H(+) translocated per cation moved in opposite direction). The apparent K(m) at pH 9.0 was 1.08, 1.30, and 68.5 mM for Li(+), Na(+), and K(+), respectively. Kinetic analyses suggested that Vc-Mrp operates in a binding exchange mode with all cations and protons competing for binding to the antiporter. The robust ion antiport activity of Vc-Mrp in sub-bacterial vesicles and its effect on bile resistance of the heterologous host make Vc-Mrp an attractive experimental model for the further studies of biochemistry and physiology of Mrp systems. Copyright 2008 S. Karger AG, Basel.

  15. Accelerated Senescence and Enhanced Disease Resistance in Hybrid Chlorosis Lines Derived from Interspecific Crosses between Tetraploid Wheat and Aegilops tauschii

    Science.gov (United States)

    Tosa, Yukio; Yoshida, Kentaro; Park, Pyoyun; Takumi, Shigeo

    2015-01-01

    Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions. PMID:25806790

  16. Accelerated senescence and enhanced disease resistance in hybrid chlorosis lines derived from interspecific crosses between tetraploid wheat and Aegilops tauschii.

    Directory of Open Access Journals (Sweden)

    Hiroki Nakano

    Full Text Available Hybrid chlorosis, a type of hybrid incompatibility, has frequently been reported in inter- and intraspecific crosses of allopolyploid wheat. In a previous study, we reported some types of growth abnormalities such as hybrid necrosis and observed hybrid chlorosis with mild or severe abnormalities in wheat triploids obtained in crosses between tetraploid wheat cultivar Langdon and four Ae. tauschii accessions and in their derived synthetic hexaploids. However, the molecular mechanisms underlying hybrid chlorosis are not well understood. Here, we compared cytology and gene expression in leaves to characterize the abnormal growth in wheat synthetics showing mild and severe chlorosis. In addition, we compared disease resistance to wheat blast fungus. In total 55 and 105 genes related to carbohydrate metabolism and 53 and 89 genes for defense responses were markedly up-regulated in the mild and severe chlorosis lines, respectively. Abnormal chloroplasts formed in the mesophyll cells before the leaves yellowed in the hybrid chlorosis lines. The plants with mild chlorosis showed increased resistance to wheat blast and powdery mildew fungi, although significant differences only in two, third internode length and maturation time, out of the examined agricultural traits were found between the wild type and plants showing mild chlorosis. These observations suggest that senescence might be accelerated in hybrid chlorosis lines of wheat synthetics. Moreover, in wheat synthetics showing mild chlorosis, the negative effects on biomass can be minimized, and they may show substantial fitness under pathogen-polluted conditions.

  17. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

    Directory of Open Access Journals (Sweden)

    Tushar Kanti Dutta

    2015-04-01

    Full Text Available Root-knot nematodes (Meloidogyne incognita cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco and soybean that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1, was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60-80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants.

  18. Enhanced corrosion resistance of stainless steel type 316 in sulphuric acid solution using eco-friendly waste product

    Science.gov (United States)

    Sanni, O.; Popoola, A. P. I.; Fayomi, O. S. I.

    2018-06-01

    Literature has shown that different organic compounds are effective corrosion inhibitors for metal in acidic environments. Such compounds usually contain oxygen, nitrogen or sulphur and function through adsorption on the metal surface, thereby creating a barrier for corrosion attack. Unfortunately, these organic compounds are toxic, scarce and expensive. Therefore, plants, natural product and natural oils have been posed as cheap, environmentally acceptable, abundant, readily available and effective molecules having low environmental impact. The corrosion resistance of austenitic stainless steel Type 316 in the presence of eco-friendly waste product was studied using weight loss and potentiodynamic polarization techniques in 0.5 M H2SO4. The corrosion rate and corrosion potential of the steel was significantly altered by the studied inhibitor. Results show that increase in concentration of the inhibitor hinders the formation of the passive film. Experimental observation shows that its pitting potential depends on the concentration of the inhibitor in the acid solution due to adsorption of anions at the metal film interface. The presence of egg shell powder had a strong influence on the corrosion resistance of stainless steel Type 316 with highest inhibition efficiency of 94.74% from weight loss analysis, this is as a result of electrochemical action and inhibition of the steel by the ionized molecules of the inhibiting compound which influenced the mechanism of the redox reactions responsible for corrosion and surface deterioration. Inhibitor adsorption fits the Langmuir isotherm model. The two methods employed for the corrosion assessment were in good agreement.

  19. APPLICATION OF METAL RESISTANT BACTERIA BY MUTATIONAL ENHANCMENT TECHNIQUE FOR BIOREMEDIATION OF COPPER AND ZINC FROM INDUSTRIAL WASTES

    Directory of Open Access Journals (Sweden)

    M. R. Shakibaie ، A. Khosravan ، A. Frahmand ، S. Zare

    2008-10-01

    Full Text Available In this research, using mutation in the metal resistant bacteria, the bioremediation of the copper and zinc from copper factory effluents was investigated. Wastewater effluents from flocculation and rolling mill sections of a factory in the city of Kerman were collected and used for further experiments. 20 strains of Pseudomonas spp. were isolated from soil and effluents surrounding factory and identified by microbiological methods. Minimum inhibitory concentrations for copper (Cu and zinc (Zn were determined by agar dilution method. Those strains that exhibited highest minimum inhibitory concentrations values to the metals (5mM were subjected to 400-3200 mg/L concentrations of the three mutagenic agents, acriflavine, acridine orange and ethidium bromide. After determination of subinhibitory concentrations, the minimum inhibitory concentrations values for copper and zinc metal ions were again determined, which showed more than 10 fold increase in minimum inhibitory concentrations value (10 mM for Cu and 20 mM for Zn with P≤0.05. The atomic absorption spectroscopy of dried biomass obtained from resistant strains after exposure to mutagenic agents revealed that strains 13 accumulate the highest amount of intracellular copper (0.35% Cu/mg dried biomass and strain 10 showed highest accumulation of zinc (0.3% Zn/mg dried biomass respectively with P≤0.05. From above results it was concluded that the treatment of industrial waste containing heavy metals by artificially mutated bacteria may be appropriate solution for effluent disposal problems.

  20. The Use of Chitosan to Enhance Photodynamic Inactivation against Candida albicans and Its Drug-Resistant Clinical Isolates

    Directory of Open Access Journals (Sweden)

    Tsuimin Tsai

    2013-04-01

    Full Text Available Drug-resistant Candida infection is a major health concern among immunocompromised patients. Antimicrobial photodynamic inactivation (PDI was introduced as an alternative treatment for local infections. Although Candida (C. has demonstrated susceptibility to PDI, high doses of photosensitizer (PS and light energy are required, which may be harmful to eukaryotic human cells. This study explores the capacity of chitosan, a polycationic biopolymer, to increase the efficacy of PDI against C. albicans, as well as fluconazole-resistant clinical isolates in planktonic or biofilm states. Chitosan was shown to effectively augment the effect of PDI mediated by toluidine blue O (TBO against C. albicans that were incubated with chitosan for 30 min following PDI. Chitosan at concentrations as low as 0.25% eradicated C. albicans; however, without PDI treatment, chitosan alone did not demonstrate significant antimicrobial activity within the 30 min of incubation. These results suggest that chitosan only augmented the fungicidal effect after the cells had been damaged by PDI. Increasing the dosage of chitosan or prolonging the incubation time allowed a reduction in the PDI condition required to completely eradicate C. albicans. These results clearly indicate that combining chitosan with PDI is a promising antimicrobial approach to treat infectious diseases.

  1. Enhancement in anomalous Hall resistivity of Co/Pd multilayer and CoPd alloy by Ga+ ion irradiation

    KAUST Repository

    Guo, Zaibing

    2014-02-01

    In this paper, we report the effect of Ga+ ion irradiation on anomalous Hall effect (AHE) and longitudinal resistivity (ρxx) in [Co(3 Å)/Pd(5 Å)]80 multilayer and Co 42Pd58 alloy. 4- and 2-fold increases in anomalous Hall resistivity (ρAH) in the Co/Pd multilayer and CoPd alloy have been observed after irradiations at doses of 2.4 × 1015 and 3.3×10 15 ions/cm2, respectively. Skew scattering and side jump contributions to AHE have been analyzed based on the scaling relationship ρAH = aρxx + bρ2xx. For the Co/Pd multilayer, AHE is mainly affected by ion irradiation-induced interface diffusion and defects. For the CoPd alloy, the increase in doses above 1.5 × 1015 ions/cm2 induces a sign change in skew scattering, followed by the skew scattering contribution to AHE overwhelming the side jump contribution, this phenomenon should be attributed to irradiation-induced defects and modifications in chemical ordering. © Copyright EPLA, 2014.

  2. To Enhance the Fire Resistance Performance of High-Speed Steel Roller Door with Water Film System

    Directory of Open Access Journals (Sweden)

    De-Hua Chung

    2015-01-01

    Full Text Available The structure of high-speed roller door with water film has improved in this study. The flameproof water film system is equipped with a water circulating device to reduce the water consumption of water film system. The water film is generated at the roller box of the high-speed roller door in this study. The heating test is done with the full-scale heating furnace. Both cases of the water film on unexposed surface and water film on exposed surface passed the fire resistance test based on ISO 834, proving that the high-speed roller door with water film system has 120A fire resistance period. The main findings indicate that the water film on exposed surface shows that as the amount of water film evaporated by high temperature inside the furnace must be greater than the evaporation capacity of water film on unexposed surface, the required water supply is 660 L more than the water film on unexposed surface.

  3. Silver nanosheet-coated copper nanowire/epoxy resin nanocomposites with enhanced electrical conductivity and wear resistance

    Energy Technology Data Exchange (ETDEWEB)

    Zeng, Ningning; Ma, Jingyi; Zhang, Yujuan; Yang, Guangbin; Zhang, Shengmao, E-mail: zsm@henu.edu.cn; Zhang, Pingyu [Henan University, Engineering Research Center for Nanomaterials (China)

    2017-03-15

    Silver (Ag) nanosheet-coated Cu nanowires (denoted as Cu@AgNWs) were prepared with a facile transmetalation reaction method. The effect of reaction conditions on the morphology and microstructure of the as-prepared Cu@AgNWs was investigated, and the thermal stability of Cu@AgNWs was evaluated by thermogravimetric analysis. In the meantime, the as-prepared Cu@AgNWs were used as the nanofillers of epoxy resin (EP), and their effect on the electrical conductivity and wear resistance of the EP-matrix composites was examined. Results indicate that the as-prepared Cu@AgNWs consist of CuNW core and Ag nanosheet shell. The Ag nanosheet shell can well inhibit the oxidation of the CuNW core, thereby providing the as-prepared Cu@AgNWs with good thermal stability even at an elevated temperature of 230 °C. The reaction temperature, Cu/Ag molar ratio, Cu dispersion concentration, and the dropping speed of silver ammonia reagent are suggested to be 40 °C, 5:1, 1% (mass fraction), and poured directly, respectively. Resultant Cu@AgNWs exhibit desired morphology and performance and can effectively increase the electrical conductivity and wear resistance of EP. This could make it feasible for the Cu@AgNW-EP composite to be applied as an electrostatic conductive material.

  4. Effect of traditional resistance and power training using rated perceived exertion for enhancement of muscle strength, power, and functional performance.

    Science.gov (United States)

    Tiggemann, Carlos Leandro; Dias, Caroline Pieta; Radaelli, Regis; Massa, Jéssica Cassales; Bortoluzzi, Rafael; Schoenell, Maira Cristina Wolf; Noll, Matias; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins

    2016-04-01

    The present study compared the effects of 12 weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75 years) were randomly assigned to traditional resistance training group (TRT; n = 15) or power training group (PT; n = 15). Participants trained twice a week for 12 weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58 %) and knee extension (≈20 %) increased significantly (p training. Muscle power also increased with training (≈27 %; p functional performance after training period (≈13 %; p effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.

  5. Enhancement of mechanical properties and corrosion resistance of friction stir welded joint of AA2014 using water cooling

    Energy Technology Data Exchange (ETDEWEB)

    Sinhmar, S., E-mail: sinhmarsunil88@gmail.com; Dwivedi, D.K.

    2017-01-27

    An investigation on the microstructure, mechanical properties, and corrosion behavior of friction stir welded joint of AA2014 in natural cooled (NC) and water cooled (WC) conditions have been reported. Optical microscopy, field emission scanning electron microscopy (FESEM) with Energy dispersive X-ray spectroscopy (EDS), Vicker's microhardness, tensile testing, X-ray diffraction (XRD), and electrochemical potentiodynamic polarization corrosion test (Tafel curve) were carried out to characterize the friction stir weld joints in both the cooling conditions. Water cooling resulted in higher strength and microhardness of friction stir weld joint compared to the natural cooling. The width of heat affected zone was reduced by the use of water cooling during friction stir welding (FSW) and minimum hardness zone was shifted towards weld center. The corrosion test was performed in 3.5% NaCl solution. Corrosion resistance of water cooled joint was found higher than natural cooled FSW joint. The precipitation behavior of weld nugget and heat affected zone impacts the corrosion resistance of FSW joint of AA 2014. Hardness, tensile, and corrosion properties of FSW joints produced under NC and WC conditions have been discussed in the light of microstructure.

  6. Electrochemical construction of micro–nano spongelike structure on titanium substrate for enhancing corrosion resistance and bioactivity

    International Nuclear Information System (INIS)

    Jiang, Pinliang; Lin, Longxiang; Zhang, Fan; Dong, Xiang; Ren, Lei; Lin, Changjian

    2013-01-01

    Highlights: • A hierarchical micro–nano spongelike TiO 2 layer was constructed on Ti substrate. • The micro–nano TiO 2 surface presented good corrosion resistance. • Excellent biomineration ability was observed on such micro–nano TiO 2 layer. • Superior MG63 cell viability was discerned on the micro–nano structured surface. -- Abstract: Surface structures of medical implants generally play a crucial role in tissue growth and healing while implanted into a living body. The surface design and modification of implants can effectively promote its biocompatibility and integration ability. In this study, a hierarchically superhydrophilic structure on titanium surface with a nano-spongelike titania layer on the micro-roughened titanium surface was constructed through dual acid etching and electrochemical treatments. It is shown that the structure of micro/nano-spongelike TiO 2 provides not only better corrosion resistance and less oxygen vacancies, but also much higher ability of biomineralization after immersion in simulated body fluid (SBF) for 14 days. It is evident, by the cell culture for the different samples, that the micro–nano spongelike structured surface on Ti significantly promotes human osteoblast-like MG63 cell attachment and proliferation. All evaluations of electrochemical behavior and biological responses in this study indicate that the micro/nano-spongelike structure on Ti surface is of excellent chemical stability, bioactivity as well as biocompatibility for biomedical implant applications

  7. Enhancement of mechanical properties and corrosion resistance of friction stir welded joint of AA2014 using water cooling

    International Nuclear Information System (INIS)

    Sinhmar, S.; Dwivedi, D.K.

    2017-01-01

    An investigation on the microstructure, mechanical properties, and corrosion behavior of friction stir welded joint of AA2014 in natural cooled (NC) and water cooled (WC) conditions have been reported. Optical microscopy, field emission scanning electron microscopy (FESEM) with Energy dispersive X-ray spectroscopy (EDS), Vicker's microhardness, tensile testing, X-ray diffraction (XRD), and electrochemical potentiodynamic polarization corrosion test (Tafel curve) were carried out to characterize the friction stir weld joints in both the cooling conditions. Water cooling resulted in higher strength and microhardness of friction stir weld joint compared to the natural cooling. The width of heat affected zone was reduced by the use of water cooling during friction stir welding (FSW) and minimum hardness zone was shifted towards weld center. The corrosion test was performed in 3.5% NaCl solution. Corrosion resistance of water cooled joint was found higher than natural cooled FSW joint. The precipitation behavior of weld nugget and heat affected zone impacts the corrosion resistance of FSW joint of AA 2014. Hardness, tensile, and corrosion properties of FSW joints produced under NC and WC conditions have been discussed in the light of microstructure.

  8. Multifunctional substrate of Al alloy based on general hierarchical micro/nanostructures: superamphiphobicity and enhanced corrosion resistance

    OpenAIRE

    Li, Xuewu; Shi, Tian; Liu, Cong; Zhang, Qiaoxin; Huang, Xingjiu

    2016-01-01

    Aluminum alloys are vulnerable to penetrating and peeling failures in seawater and preparing a barrier coating to isolate the substrate from corrosive medium is an effective anticorrosion method. Inspired by the lotus leaves effect, a wetting alloy surface with enhanced anticorrosion behavior has been prepared via etch, deposition, and low-surface-energy modification. Results indicate that excellent superamphiphobicity has been achieved after the modification of the constructed hierarchical l...

  9. Training social workers to enhance patient-centered care for drug-resistant TB-HIV in South Africa.

    Science.gov (United States)

    Zelnick, J R; Seepamore, B; Daftary, A; Amico, K R; Bhengu, X; Friedland, G; Padayatchi, N; Naidoo, K; O'Donnell, M R

    2018-03-21

    KwaZulu-Natal, South Africa, is the epicenter of an epidemic of drug-resistant tuberculosis (DR-TB) and human immunodeficiency virus (HIV) co-infection, characterized by low rates of medication adherence and retention in care. Social workers may have a unique role to play in improving DR-TB-HIV outcomes. We designed, implemented and evaluated a model-based pilot training course on patient-centered care, treatment literacy in DR-TB and HIV coinfection, patient support group facilitation, and self-care. Ten social workers participated in a 1-day training course. Post-training questionnaire scores showed significant overall gains ( P = 0.003). A brief training intervention may be a useful and feasible way to engage social workers in patient-centered care for DR-TB and HIV coinfection.

  10. Enhanced resistance to herpes simplex virus type 1 infection in transgenic mice expressing a soluble form of herpesvirus entry mediator

    International Nuclear Information System (INIS)

    Ono, Etsuro; Yoshino, Saori; Amagai, Keiko; Taharaguchi, Satoshi; Kimura, Chiemi; Morimoto, Junko; Inobe, Manabu; Uenishi, Tomoko; Uede, Toshimitsu

    2004-01-01

    Herpesvirus entry mediator (HVEM) is a member of the tumor necrosis factor (TNF) receptor family used as a cellular receptor by virion glycoprotein D (gD) of herpes simplex virus (HSV). Both human and mouse forms of HVEM can mediate entry of HSV-1 but have no entry activity for pseudorabies virus (PRV). To assess the antiviral potential of HVEM in vivo, three transgenic mouse lines expressing a soluble form of HVEM (HVEMIg) consisting of an extracellular domain of murine HVEM and the Fc portion of human IgG1 were generated. All of the transgenic mouse lines showed marked resistance to HSV-1 infection when the mice were challenged intraperitoneally with HSV-1, but not to PRV infection. The present results demonstrate that HVEMIg is able to exert a significant antiviral effect against HSV-1 infection in vivo

  11. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene.

    Science.gov (United States)

    Thakur, Nidhi; Upadhyay, Santosh Kumar; Verma, Praveen C; Chandrashekar, Krishnappa; Tuli, Rakesh; Singh, Pradhyumna K

    2014-01-01

    Expression of double strand RNA (dsRNA) designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi), thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci) upon oral feeding. The v-ATPase subunit A (v-ATPaseA) coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation. Transgenic tobacco lines were developed for the expression of long dsRNA precursor to make siRNA and knock down the v-ATPaseA mRNA in whitefly. Molecular analysis and insecticidal properties of the transgenic plants established the formation of siRNA targeting the whitefly v-ATPaseA, in the leaves. The transcript level of v-ATPaseA in whiteflies was reduced up to 62% after feeding on the transgenic plants. Heavy infestation of whiteflies on the control plants caused significant loss of sugar content which led to the drooping of leaves. The transgenic plants did not show drooping effect. Host plant derived pest resistance was achieved against whiteflies by genetic transformation of tobacco which generated siRNA against the whitefly v-ATPaseA gene. Transgenic tobacco lines expressing dsRNA of v-ATPaseA, delivered sufficient siRNA to whiteflies feeding on them, mounting a significant silencing response, leading to their mortality. The transcript level of the target gene was reduced in whiteflies feeding on transgenic plants. The strategy can be taken up for genetic engineering of plants to control whiteflies in field crops.

  12. Enhanced whitefly resistance in transgenic tobacco plants expressing double stranded RNA of v-ATPase A gene.

    Directory of Open Access Journals (Sweden)

    Nidhi Thakur

    Full Text Available BACKGROUND: Expression of double strand RNA (dsRNA designed against important insect genes in transgenic plants have been shown to give protection against pests through RNA interference (RNAi, thus opening the way for a new generation of insect-resistant crops. We have earlier compared the efficacy of dsRNAs/siRNAs, against a number of target genes, for interference in growth of whitefly (Bemisia tabaci upon oral feeding. The v-ATPase subunit A (v-ATPaseA coding gene was identified as a crucial target. We now report the effectiveness of transgenic tobacco plants expressing siRNA to silence v-ATPaseA gene expression for the control of whitefly infestation. METHODOLOGY/PRINCIPAL FINDINGS: Transgenic tobacco lines were developed for the expression of long dsRNA precursor to make siRNA and knock down the v-ATPaseA mRNA in whitefly. Molecular analysis and insecticidal properties of the transgenic plants established the formation of siRNA targeting the whitefly v-ATPaseA, in the leaves. The transcript level of v-ATPaseA in whiteflies was reduced up to 62% after feeding on the transgenic plants. Heavy infestation of whiteflies on the control plants caused significant loss of sugar content which led to the drooping of leaves. The transgenic plants did not show drooping effect. CONCLUSIONS/SIGNIFICANCE: Host plant derived pest resistance was achieved against whiteflies by genetic transformation of tobacco which generated siRNA against the whitefly v-ATPaseA gene. Transgenic tobacco lines expressing dsRNA of v-ATPaseA, delivered sufficient siRNA to whiteflies feeding on them, mounting a significant silencing response, leading to their mortality. The transcript level of the target gene was reduced in whiteflies feeding on transgenic plants. The strategy can be taken up for genetic engineering of plants to control whiteflies in field crops.

  13. Minimal dose of milk protein concentrate to enhance the anabolic signalling response to a single bout of resistance exercise; a randomised controlled trial.

    Science.gov (United States)

    Mitchell, Cameron J; Zeng, Nina; D'Souza, Randall F; Mitchell, Sarah M; Aasen, Kirsten; Fanning, Aaron C; Poppitt, Sally D; Cameron-Smith, David

    2017-01-01

    Resistance training is a potent stimulus to induce muscle hypertrophy. Supplemental protein intake is known to enhance gains in muscle mass through activation of the mammalian target of rapamycin complex 1 (mTORC1) pathway, which initiates protein translation. While the optimal dose of high quality protein to promote post exercise anabolism in young or older men has been investigated, little is known about the minimum doses of protein required to potentiate the resistance exercise activation of anabolic signalling in middle aged men. Twenty healthy men (46.3 ± 5.7 years, BMI: 23.9 ± 6.6 kg/m 2 ) completed a single bout of unilateral resistance exercise consisting of 4 sets of leg extension and press at 80% of 1 repetition maximum. Participants were randomised to consume either formulated milk product containing 9 g milk protein (FMP) or an isoenergetic carbohydrate placebo (CHO) immediately post exercise, in a double blind fashion. A single muscle biopsy was collected at pre-exercise baseline and then bilateral biopsies were collected 90 and 240 min after beverage consumption. P70S6K Thr389 phosphorylation was increased with exercise irrespective of group, P70S6K Thr421/Ser424 was increased with exercise only in the FMP group at 240 min. Likewise, rpS6 Ser235/236 phosphorylation was increased with exercise irrespective of group, rpS6 Ser240/244 increased to a greater extent following exercise in the FMP group. mRNA expression of the amino acid transporter, LAT1/ SLC7A5 increased with both exercise and beverage consumption irrespective of group. PAT1/ SLC36A1 , CAT1/ SLC7A1 and SNAT2/ SLC38A2 mRNA increased only after exercise regardless of group. Nine grams of milk protein is sufficient to augment some measures of downstream mTORC1 signalling after resistance exercise but does not potentiate exercise induced increases in amino acid transporter expression. Formulated products containing nine grams of milk protein would be expected stimulate muscle

  14. Aqueously Dispersed Silver Nanoparticle-Decorated Boron Nitride Nanosheets for Reusable, Thermal Oxidation-Resistant Surface Enhanced Raman Spectroscopy (SERS) Devices

    Science.gov (United States)

    Lin, Yi; Bunker, Christopher E.; Fernandos, K. A. Shiral; Connell, John W.

    2012-01-01

    The impurity-free aqueous dispersions of boron nitride nanosheets (BNNS) allowed the facile preparation of silver (Ag) nanoparticle-decorated BNNS by chemical reduction of an Ag salt with hydrazine in the presence of BNNS. The resultant Ag-BNNS nanohybrids remained dispersed in water, allowing convenient subsequent solution processing. By using substrate transfer techniques, Ag-BNNS nanohybrid thin film coatings on quartz substrates were prepared and evaluated as reusable surface enhanced Raman spectroscopy (SERS) sensors that were robust against repeated solvent washing. In addition, because of the unique thermal oxidation-resistant properties of the BNNS, the sensor devices may be readily recycled by short-duration high temperature air oxidation to remove residual analyte molecules in repeated runs. The limiting factor associated with the thermal oxidation recycling process was the Ostwald ripening effect of Ag nanostructures.

  15. The enhanced resistance to K deactivation of Ce/TiO2 catalyst for NH3-SCR reaction by the modification with P

    Science.gov (United States)

    Li, Ming-yuan; Guo, Rui-tang; Hu, Chang-xing; Sun, Peng; Pan, Wei-guo; Liu, Shu-ming; Sun, Xiao; Liu, Shuai-wei; Liu, Jian

    2018-04-01

    The deactivation of SCR catalyst caused by K species contained in the fly ash would suppress its DeNOx performance. In this study, it was manifested that the modification of Ce/TiO2 catalyst with P could enhance its K tolerance. To understand the promotion mechanism, the fresh and poisoned catalyst samples were subjected to the characterization techniques including BET, XRD, XPS, H2-TPR, NH3-TPD and in situ DRIFT. The results elucidated that the introduction of P species could increase the reducibility of Ce species and generate more surface chemisorbed oxygen, along with the strengthened surface acidity for NH3 adsorption. It seemed that the NH3-SCR reaction mechanism over Ce/TiO2 catalyst was a combination of L-H mechanism (reason for its good K resistance.

  16. Contribution to the study of physico-chemical properties of surfaces modified by laser treatment. Application to the enhancement of localized corrosion resistance of stainless steels

    International Nuclear Information System (INIS)

    Pacquentin, W.

    2011-01-01

    Metallic materials are more and more used in severe conditions with particularly strong request for improving their behavior in aggressive environment and especially over long periods. The objective of this PhD work is to estimate the potentiality of a laser surface melting treatment on the improvement of the stainless steel 304L corrosion resistance, surface treatments by laser can be revisited on the basis of a recent change in the laser technology. In the frame of this work, a nano-pulsed laser fiber was chosen: it allows the treated surface to be melted for few microns in depth, followed by an ultra-fast solidification occurring with cooling rates up to 1011 K/s. The combination of these processes leads to the elimination of the surface defects, the formation (trapping) of metastable phases, the segregation of chemical elements and the growth of a new oxide layer which properties are governed by the laser parameters. To correlate these latter to the electrochemical reactivity of the surface, the influence of two laser parameters on the physico-chemical properties of the surface was studied: the laser power and the overlap of the laser impacts. To support this approach, the pitting corrosion resistance of the samples was determined by standard electrochemical tests. For specific laser parameters, the pitting potential of a 304L stainless steel was increased by more than 500 mV corresponding to an important enhancement in localized corrosion resistance in chloride environment. The interdependence of the different phenomena resulting from the laser treatment lead to a quite complex prioritization of their role on the sensibility of the 304L. However, it was demonstrated that the nature of the thermal oxide formed during the laser surface melting and the induced defects are first-order parameters for the initiation of pits. (author) [fr

  17. Can-miRn37a mediated suppression of ethylene response factors enhances the resistance of chilli against anthracnose pathogen Colletotrichum truncatum L.

    Science.gov (United States)

    Mishra, Rukmini; Mohanty, Jatindra Nath; Chand, Subodh Kumar; Joshi, Raj Kumar

    2018-02-01

    Pepper anthracnose, caused by Colletotrichum species complex is the most destructive disease of chilli (Capsicum annuum L.). miRNAs are key modulators of transcriptional and post- transcriptional expression of genes during defense responses. In the present study, we performed a comparative miRNA profiling of susceptible (Arka Lohit-AL) and resistant (Punjab Lal-PL) chilli cultivars to identify 35 differentially expressed miRNAs that could be classified as positive, negative or basal regulators of defense against C. truncatum, the most potent anthracnose pathogen. Interestingly, a novel microRNA can-miRn37a was significantly induced in PL but largely repressed in AL genotype post pathogen attack. Subsequent over-expression of can-miRn37a in AL showed enhanced resistance to anthracnose, as evidenced by decreased fungal growth and induced expression of defense-related genes. Consequently, the expression of its three target genes encoding the ethylene response factors (ERFs) was down-regulated in PL as well as in the over-expression lines of AL genotypes. The ability of these targets to be regulated by can-miRn37a was further confirmed by transient co-expression in Nicotiana benthamiana. Additionally, the virus-induced silencing of the three targets in the susceptible AL cultivar revealed their role in fungal colonization and induction of C. truncatum pathogenicity in chilli. Taken together, our study suggests that can-miRn37a provides a potential miRNA mediated approach of engineering anthracnose resistance in chilli by repressing ERFs and preventing fungal colonization. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Caffeic acid phenethylester increases stress resistance and enhances lifespan in Caenorhabditis elegans by modulation of the insulin-like DAF-16 signalling pathway.

    Science.gov (United States)

    Havermann, Susannah; Chovolou, Yvonni; Humpf, Hans-Ulrich; Wätjen, Wim

    2014-01-01

    CAPE is an active constituent of propolis which is widely used in traditional medicine. This hydroxycinnamic acid derivate is a known activator of the redox-active Nrf2 signalling pathway in mammalian cells. We used C. elegans to investigate the effects of this compound on accumulation of reactive oxygen species and the modulation of the pivotal redox-active pathways SKN-1 and DAF-16 (homologues of Nrf2 and FoxO, respectively) in this model organism; these results were compared to the effects in Hct116 human colon carcinoma cells. CAPE exerts a strong antioxidative effect in C. elegans: The increase of reactive oxygen species induced by thermal stress was diminished by about 50%. CAPE caused a nuclear translocation of DAF-16, but not SKN-1. CAPE increased stress resistance of the nematode against thermal stress and finally a prolongation of the median and maximum lifespan by 9 and 17%, respectively. This increase in stress resistance and lifespan was dependent on DAF-16 as shown in experiments using a DAF-16 loss of function mutant strain. Life prolongation was retained under SKN-1 RNAi conditions showing that the effect is SKN-1 independent. The results of CAPE obtained in C. elegans differed from the results obtained in Hct116 colon carcinoma cells: CAPE also caused strong antioxidative effects in the mammalian cells, but no activation of the FoxO4 signalling pathway was detectable. Instead, an activation of the Nrf2 signalling pathway was shown by luciferase assay and western blots. CAPE activates the insulin-like DAF-16, but not the SKN-1 signalling pathway in C. elegans and therefore enhances the stress resistance and lifespan of this organism. Since modulation of the DAF-16 pathway was found to be a pivotal effect of CAPE in C. elegans, this has to be taken into account for the investigation of the molecular mechanisms of the traditional use of propolis.

  19. Using pre-distorted PAM-4 signal and parallel resistance circuit to enhance the passive solar cell based visible light communication

    Science.gov (United States)

    Wang, Hao-Yu; Wu, Jhao-Ting; Chow, Chi-Wai; Liu, Yang; Yeh, Chien-Hung; Liao, Xin-Lan; Lin, Kun-Hsien; Wu, Wei-Liang; Chen, Yi-Yuan

    2018-01-01

    Using solar cell (or photovoltaic cell) for visible light communication (VLC) is attractive. Apart from acting as a VLC receiver (Rx), the solar cell can provide energy harvesting. This can be used in self-powered smart devices, particularly in the emerging ;Internet of Things (IoT); networks. Here, we propose and demonstrate for the first time using pre-distortion pulse-amplitude-modulation (PAM)-4 signal and parallel resistance circuit to enhance the transmission performance of solar cell Rx based VLC. Pre-distortion is a simple non-adaptive equalization technique that can significantly mitigate the slow charging and discharging of the solar cell. The equivalent circuit model of the solar cell and the operation of using parallel resistance to increase the bandwidth of the solar cell are discussed. By using the proposed schemes, the experimental results show that the data rate of the solar cell Rx based VLC can increase from 20 kbit/s to 1.25 Mbit/s (about 60 times) with the bit error-rate (BER) satisfying the 7% forward error correction (FEC) limit.

  20. Loss of insulin-like growth factor II imprinting is a hallmark associated with enhanced chemo/radiotherapy resistance in cancer stem cells.

    Science.gov (United States)

    Zhao, Xin; Liu, Xiaoliang; Wang, Guanjun; Wen, Xue; Zhang, Xiaoying; Hoffman, Andrew R; Li, Wei; Hu, Ji-Fan; Cui, Jiuwei

    2016-08-09

    Insulin-like growth factor II (IGF2) is maternally imprinted in most tissues, but the epigenetic regulation of the gene in cancer stem cells (CSCs) has not been defined. To study the epigenetic mechanisms underlying self-renewal, we isolated CSCs and non-CSCs from colon cancer (HT29, HRT18, HCT116), hepatoma (Hep3B), breast cancer (MCF7) and prostate cancer (ASPC) cell lines. In HT29 and HRT18 cells that show loss of IGF2 imprinting (LOI), IGF2 was biallelically expressed in the isolated CSCs. Surprisingly, we also found loss of IGF2 imprinting in CSCs derived from cell lines HCT116 and ASPC that overall demonstrate maintenance of IGF2 imprinting. Using chromatin conformation capture (3C), we found that intrachromosomal looping between the IGF2 promoters and the imprinting control region (ICR) was abrogated in CSCs, in parallel with loss of IGF2 imprinting in these CSCs. Loss of imprinting led to increased IGF2 expression in CSCs, which have a higher rate of colony formation and greater resistance to chemotherapy and radiotherapy in vitro. These studies demonstrate that IGF2 LOI is a common feature in CSCs, even when the stem cells are derived from a cell line in which the general population of cells maintain IGF2 imprinting. This finding suggests that aberrant IGF2 imprinting may be an intrinsic epigenetic control mechanism that enhances stemness, self-renewal and chemo/radiotherapy resistance in cancer stem cells.

  1. Overexpression of Rice Auxilin-Like Protein, XB21, Induces Necrotic Lesions, up-Regulates Endocytosis-Related Genes, and Confers Enhanced Resistance to Xanthomonas oryzae pv. oryzae.

    Science.gov (United States)

    Park, Chang-Jin; Wei, Tong; Sharma, Rita; Ronald, Pamela C

    2017-12-01

    The rice immune receptor XA21 confers resistance to the bacterial pathogen, Xanthomonas oryzae pv. oryzae (Xoo). To elucidate the mechanism of XA21-mediated immunity, we previously performed a yeast two-hybrid screening for XA21 interactors and identified XA21 binding protein 21 (XB21). Here, we report that XB21 is an auxilin-like protein predicted to function in clathrin-mediated endocytosis. We demonstrate an XA21/XB21 in vivo interaction using co-immunoprecipitation in rice. Overexpression of XB21 in rice variety Kitaake and a Kitaake transgenic line expressing XA21 confers a necrotic lesion phenotype and enhances resistance to Xoo. RNA sequencing reveals that XB21 overexpression results in the differential expression of 8735 genes (4939 genes up- and 3846 genes down-regulated) (≥2-folds, FDR ≤0.01). The up-regulated genes include those predicted to be involved in 'cell death' and 'vesicle-mediated transport'. These results indicate that XB21 plays a role in the plant immune response and in regulation of cell death. The up-regulation of genes controlling 'vesicle-mediated transport' in XB21 overexpression lines is consistent with a functional role for XB21 as an auxilin.

  2. A novel approach in acidic disinfection through inhibition of acid resistance mechanisms; Maleic acid-mediated inhibition of glutamate decarboxylase activity enhances acid sensitivity of Listeria monocytogenes.

    Science.gov (United States)

    Paudyal, Ranju; Barnes, Ruth H; Karatzas, Kimon Andreas G

    2018-02-01

    Here it is demonstrated a novel approach in disinfection regimes where specific molecular acid resistance systems are inhibited aiming to eliminate microorganisms under acidic conditions. Despite the importance of the Glutamate Decarboxylase (GAD) system for survival of Listeria monocytogenes and other pathogens under acidic conditions, its potential inhibition by specific compounds that could lead to its elimination from foods or food preparation premises has not been studied. The effects of maleic acid on the acid resistance of L. monocytogenes were investigated and found that it has a higher antimicrobial activity under acidic conditions than other organic acids, while this could not be explained by its pKa or Ka values. The effects were found to be more pronounced on strains with higher GAD activity. Maleic acid affected the extracellular GABA levels while it did not affect the intracellular ones. Maleic acid had a major impact mainly on GadD2 activity as also shown in cell lysates. Furthermore, it was demonstrated that maleic acid is able to partly remove biofilms of L. monocytogenes. Maleic acid is able to inhibit the GAD of L. monocytogenes significantly enhancing its sensitivity to acidic conditions and together with its ability to remove biofilms, make a good candidate for disinfection regimes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. The effect of substrate bias voltages on impact resistance of CrAlN coatings deposited by modified ion beam enhanced magnetron sputtering

    Science.gov (United States)

    Chunyan, Yu; Linhai, Tian; Yinghui, Wei; Shebin, Wang; Tianbao, Li; Bingshe, Xu

    2009-01-01

    CrAlN coatings were deposited on silicon and AISI H13 steel substrates using a modified ion beam enhanced magnetron sputtering system. The effect of substrate negative bias voltages on the impact property of the CrAlN coatings was studied. The X-ray diffraction (XRD) data show that all CrAlN coatings were crystallized in the cubic NaCl B1 structure, with the (1 1 1), (2 0 0) (2 2 0) and (2 2 2) diffraction peaks observed. Two-dimensional surface morphologies of CrAlN coatings were investigated by atomic force microscope (AFM). The results show that with increasing substrate bias voltage the coatings became more compact and denser, and the microhardness and fracture toughness of the coatings increased correspondingly. In the dynamic impact resistance tests, the CrAlN coatings displayed better impact resistance with the increase of bias voltage, due to the reduced emergence and propagation of the cracks in coatings with a very dense structure and the increase of hardness and fracture toughness in coatings.

  4. Cr-resistant rhizo- and endophytic bacteria associated with Prosopis juliflora and their potential as phytoremediation enhancing agents in metal-degraded soils.

    Science.gov (United States)

    Khan, Muhammad U; Sessitsch, Angela; Harris, Muhammad; Fatima, Kaneez; Imran, Asma; Arslan, Muhammad; Shabir, Ghulam; Khan, Qaiser M; Afzal, Muhammad

    2014-01-01

    Prosopis juliflora is characterized by distinct and profuse growth even in nutritionally poor soil and environmentally stressed conditions and is believed to harbor some novel heavy metal-resistant bacteria in the rhizosphere and endosphere. This study was performed to isolate and characterize Cr-resistant bacteria from the rhizosphere and endosphere of P. juliflora growing on the tannery effluent contaminated soil. A total of 5 and 21 bacterial strains were isolated from the rhizosphere and endosphere, respectively, and were shown to tolerate Cr up to 3000 mg l(-1). These isolates also exhibited tolerance to other toxic heavy metals such as, Cd, Cu, Pb, and Zn, and high concentration (174 g l(-1)) of NaCl. Moreover, most of the isolated bacterial strains showed one or more plant growth-promoting activities. The phylogenetic analysis of the 16S rRNA gene showed that the predominant species included Bacillus, Staphylococcus and Aerococcus. As far as we know, this is the first report analyzing rhizo- and endophytic bacterial communities associated with P. juliflora growing on the tannery effluent contaminated soil. The inoculation of three isolates to ryegrass (Lolium multiflorum L.) improved plant growth and heavy metal removal from the tannery effluent contaminated soil suggesting that these bacteria could enhance the establishment of the plant in contaminated soil and also improve the efficiency of phytoremediation of heavy metal-degraded soils.

  5. Development of liposomal pemetrexed for enhanced therapy against multidrug resistance mediated by ABCC5 in breast cancer

    Directory of Open Access Journals (Sweden)

    Bai F

    2018-03-01

    Full Text Available Fang Bai,1–3,* You Yin,4,* Ting Chen,1,* Jihui Chen,1 Meixin Ge,2 Yunshu Lu,2 Fangyuan Xie,5 Jian Zhang,1 Kejin Wu,3 Yan Liu1,6 1Department of Pharmacy, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 2Department of General Surgery, Xinhua Hospital, Affiliated to Shanghai Jiao Tong University, School of Medicine, Shanghai, 3Department of Breast Surgery, Obstetrics and Gynaecology Hospital, Fudan University, Shanghai, 4Department of Neurology, Changzheng Hospital Affiliated to Second Military Medical University, Shanghai, 5Department of Pharmacy, Shanghai Eastern Hepatobiliary Surgery Hospital, Shanghai, 6Department of Pharmacy, Changzheng Hospital Affiliated to Second Military Medical University, Shanghai, People’s Republic of China *These authors contributed equally to this work Purpose: Breast cancer is the most common cancer among women. Pemetrexed, a new generation antifolate drug, is one of the primary treatments for breast cancer. However, multidrug resistance (MDR in breast cancer greatly hampers the therapeutic efficacy of chemotherapies such as pemetrexed. Nanomedicine is emerging as a promising alternative technique to overcome cancer MDR. Thus, pemetrexed-loaded d-alpha tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS liposomes (liposomal pemetrexed were developed as a strategy to overcome MDR to pemetrexed in breast cancer. Materials and methods: Liposomal pemetrexed was developed using the calcium acetate gradient method. The cytotoxic effects, apoptosis-inducing activity, in vivo distribution, and antitumor activity of liposomal pemetrexed were investigated. Results: Liposomal pemetrexed was small in size (160.77 nm, with a small polydispersity of <0.1. The encapsulation efficacy of liposomal pemetrexed was 63.5%, which is rather high for water-soluble drugs in liposomes. The IC50 of liposomal pemetrexed following treatment with MDR breast cancer cells (MCF-7 cells overexpressing ABCC5

  6. Cocaine enhances resistance to extinction of responding for brain-stimulation reward in adult prenatally stressed rats.

    Science.gov (United States)

    Gao, Shuibo; Suenaga, Toshiko; Oki, Yutaka; Yukie, Masao; Nakahara, Daiichiro

    2011-10-01

    The present experiment assessed whether prenatal stress (PS) can alter the ability of acute and chronic cocaine administration to increase and decrease the rewarding effectiveness of the medial forebrain bundle (MFB) using intracranial self-stimulation (ICSS), and also whether PS can affect the extinction of the MFB stimulation response. Adult male offspring of female rats that received PS or no PS (nPS) were implanted with MFB stimulating electrodes, and were then tested in ICSS paradigms. In both nPS and PS offspring, acute cocaine injection decreased ICSS thresholds dose-dependently. However, the threshold-lowering effects at any dose were not significantly different between groups. There was also no group-difference in the threshold-elevating effects of chronic cocaine administration. Nevertheless, chronically drug-administered PS rats exhibited a resistance to the extinguishing of the response for brain-stimulation reward when acutely treated with cocaine, as compared to extinction without cocaine treatment. The results suggest that PS may weaken the ability for response inhibition under cocaine loading in male adult offspring. Copyright © 2011 Elsevier B.V. All rights reserved.

  7. LncRNA HOTAIR Enhances the Androgen-Receptor-Mediated Transcriptional Program and Drives Castration-Resistant Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Ali Zhang

    2015-10-01

    Full Text Available Understanding the mechanisms of androgen receptor (AR activation in the milieu of low androgen is critical to effective treatment of castration-resistant prostate cancer (CRPC. Here, we report HOTAIR as an androgen-repressed lncRNA, and, as such, it is markedly upregulated following androgen deprivation therapies and in CRPC. We further demonstrate a distinct mode of lncRNA-mediated gene regulation, wherein HOTAIR binds to the AR protein to block its interaction with the E3 ubiquitin ligase MDM2, thereby preventing AR ubiquitination and protein degradation. Consequently, HOTAIR expression is sufficient to induce androgen-independent AR activation and drive the AR-mediated transcriptional program in the absence of androgen. Functionally, HOTAIR overexpression increases, whereas HOTAIR knockdown decreases, prostate cancer cell growth and invasion. Taken together, our results provide compelling evidence of lncRNAs as drivers of androgen-independent AR activity and CRPC progression, and they support the potential of lncRNAs as therapeutic targets.

  8. Program of enhancing the Korea-USA cooperation research for the development of proliferation resistant fuel cycle technology

    International Nuclear Information System (INIS)

    Yang, Myung Seung; Ahn, D. H.; Ko, W. I.

    2007-03-01

    The objective of the Program is to develop the fuel cycle technology of GEN-IV SFR (Sodium Fast Reactor) system through the Korea-USA cooperation research in order to improve the efficiency of the technology development and to increase the transparency of the research. Since the pyroprocessing research by using actual spent nuclear fuel can not be performed in Korea at present, the active demonstration research will be performed by using the USA national research facilities under the Korea-USA cooperation. Moreover, the development of safeguards technology and the methodology for the evaluation of the proliferation resistance will also be performed under the cooperation. The current cooperation national laboratories of the safeguards and pyroprocessing technology development are LANL (Los Alamos National Lab.) and INL (Idaho National Lab.), respectively. Practical research experience and technical data for the pyroprocessing technology can be achieved through the demonstration of the inactive research results, which was performed in Korea, by using actual spent nuclear fuel. The scope of the cooperation study encompass the electrolytic reduction of oxide spent fuel, electrorefining, liquid cadmium cathode process, TRU fuel fabrication, fuel performance evaluation and related safeguards technology development

  9. Loss of Synapse Repressor MDGA1 Enhances Perisomatic Inhibition, Confers Resistance to Network Excitation, and Impairs Cognitive Function

    Directory of Open Access Journals (Sweden)

    Steven A. Connor

    2017-12-01

    Full Text Available Synaptopathies contributing to neurodevelopmental disorders are linked to mutations in synaptic organizing molecules, including postsynaptic neuroligins, presynaptic neurexins, and MDGAs, which regulate their interaction. The role of MDGA1 in suppressing inhibitory versus excitatory synapses is controversial based on in vitro studies. We show that genetic deletion of MDGA1 in vivo elevates hippocampal CA1 inhibitory, but not excitatory, synapse density and transmission. Furthermore, MDGA1 is selectively expressed by pyramidal neurons and regulates perisomatic, but not distal dendritic, inhibitory synapses. Mdga1−/− hippocampal networks demonstrate muted responses to neural excitation, and Mdga1−/− mice are resistant to induced seizures. Mdga1−/− mice further demonstrate compromised hippocampal long-term potentiation, consistent with observed deficits in spatial and context-dependent learning and memory. These results suggest that mutations in MDGA1 may contribute to cognitive deficits through altered synaptic transmission and plasticity by loss of suppression of inhibitory synapse development in a subcellular domain- and cell-type-selective manner.

  10. Corrosion resistance enhancement of Ni-P-nano SiO{sub 2} composite coatings on aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Sadreddini, Sina, E-mail: sina.sadreddini1986@gmail.com [Department of Materials Science and Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Afshar, Abdollah [Department of Materials Science and Engineering, Sharif university of Technology, Tehran (Iran, Islamic Republic of)

    2014-06-01

    In this study, the influences of different concentrations of SiO{sub 2} nano sized particles in the bath on deposition rate, surface morphology and corrosion behavior of Ni-P-SiO{sub 2} Composite coatings were investigated. The deposition rate of coating was influenced by incorporation of SiO{sub 2} particles. The microstructure was investigated with field emission scanning electron microscopy (FESEM). The amount of SiO{sub 2} was examined by Energy Dispersive Analysis of X-Ray (EDX) and amount of SiO{sub 2} nanoparticles co-deposited reached a maximum value at 4.5 %wt. Corrosion behavior of coated aluminum was evaluated by electrochemical impedance spectroscopy (EIS) and polarization techniques. The results illustrated that the corrosion rate decreases (6.5–0.6 μA/cm{sup 2}) and the corrosion potential increases (−0.64 to −0.3) with increasing the quantity of the SiO{sub 2} nanoparticles in the bath. Moreover, Ni-p-SiO{sub 2} nano-composite coating possesses less porosity than that in Ni-P coating, resulting in improving corrosion resistance.

  11. Enhanced brain disposition and effects of Δ9-tetrahydrocannabinol in P-glycoprotein and breast cancer resistance protein knockout mice.

    Directory of Open Access Journals (Sweden)

    Adena S Spiro

    Full Text Available The ABC transporters P-glycoprotein (P-gp, Abcb1 and breast cancer resistance protein (Bcrp, Abcg2 regulate the CNS disposition of many drugs. The main psychoactive constituent of cannabis Δ(9-tetrahydrocannabinol (THC has affinity for P-gp and Bcrp, however it is unknown whether these transporters modulate the brain accumulation of THC and its functional effects on the CNS. Here we aim to show that mice devoid of Abcb1 and Abcg2 retain higher brain THC levels and are more sensitive to cannabinoid-induced hypothermia than wild-type (WT mice. Abcb1a/b (-/-, Abcg2 (-/- and wild-type (WT mice were injected with THC before brain and blood were collected and THC concentrations determined. Another cohort of mice was examined for THC-induced hypothermia by measuring rectal body temperature. Brain THC concentrations were higher in both Abcb1a/b (-/- and Abcg2 (-/- mice than WT mice. ABC transporter knockout mice exhibited delayed elimination of THC from the brain with the effect being more prominent in Abcg2 (-/- mice. ABC transporter knockout mice were more sensitive to THC-induced hypothermia compared to WT mice. These results show P-gp and Bcrp prolong the brain disposition and hypothermic effects of THC and offer a novel mechanism for both genetic vulnerability to the psychoactive effects of cannabis and drug interactions between CNS therapies and cannabis.

  12. Plant Growth Enhancement, Disease Resistance, and Elemental Modulatory Effects of Plant Probiotic Endophytic Bacillus sp. Fcl1.

    Science.gov (United States)

    Jayakumar, Aswathy; Krishna, Arathy; Mohan, Mahesh; Nair, Indu C; Radhakrishnan, E K

    2018-04-13

    Endophytic bacteria have already been studied for their beneficial support to plants to manage both biotic and abiotic stress through an array of well-established mechanisms. They have either direct or indirect impact on mobilizing diverse nutrients and elements from soil to plants. However, detailed insight into the fine-tuning of plant elemental composition by associated microorganism is very limited. In this study, endophytic Bacillus Fcl1 characterized from the rhizome of Curcuma longa was found to have broad range of plant growth-promoting and biocontrol mechanisms. The organism was found to have indole acetic acid and 1-aminocyclopropane-1-carboxylate deaminase production properties along with nitrogen fixation. The Bacillus Fcl1 could also inhibit diverse phytopathogens as confirmed by dual culture and well diffusion. By LC-MS/MS analysis, chemical basis of its antifungal activity has been proved to be due to the production of iturin A and a blend of surfactin compounds. Moreover, the organism was found to induce both plant growth and disease resistance in vivo in model plant system. Because of these experimentally demonstrated multiple plant probiotic features, Bacillus Fcl1 was selected as a candidate organism to study its role in modulation of plant elemental composition. ICP-MS analysis of Bacillus Fcl1-treated plants provided insight into relation of bacterial interaction with elemental composition of plants.

  13. Suppressing miRNA-15a/-16 expression by interleukin-6 enhances drug-resistance in myeloma cells

    Directory of Open Access Journals (Sweden)

    Chang Hong

    2011-09-01

    Full Text Available Abstract The bone marrow microenvironment facilitates the survival, differentiation, and proliferation of myeloma (MM cells. This study identified that microRNA-15a and -16 expressions tightly correlated with proliferation and drug sensitivity of MM cells. miRNA-15a/-16 expression in MM cells was significantly increased after treatment with cytotoxic agents. The interaction of bone marrow stromal cells (BMSC with MM cells resulted in decreased miRNA-15a/-16 expression and promoted the survival of the MM cells. Interleukin-6 (IL-6 produced by BMSCs suppressed the expression of miRNA-15a and 16 in a time- and dose- dependent pattern, with the suppression on miRNA-15a being more significant than on miRNA-16. miRNA-15a-transfected MM cells were found to be arrested in G1/S checkpoint, and the transfected MM cells had decreased growth and survival. In conclusion, our data suggest that via suppressing miRNA-15a and -16 expressions, IL-6 secreted by BMSCs promotes drug-resistance in myeloma cells.

  14. Enhanced Production and Characterization of a Solvent Stable Amylase from Solvent Tolerant Bacillus tequilensis RG-01: Thermostable and Surfactant Resistant

    Directory of Open Access Journals (Sweden)

    Soni Tiwari

    2014-01-01

    Full Text Available Ten bacterial strains isolated from the soil samples in the presence of cyclohexane were screened for amylase production. Among them, culture RG-01 was adjudged as the best amylase producer and was identified as Bacillus tequilensis from MTCC, Chandigarh. The isolate showed maximum amylase production (8100 U/mL in the presence of starch, peptone, and Ca2+ ions at 55°C pH 7.0 within 24 h of incubation. The enzyme was stable in the presence of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the amylase stability, respectively. The enzyme was showed it 100% activity at 55°C and pH 7.0 with 119% and 127% stability at 55°C and pH 7.0, respectively. The enzyme was also stable in the presence of SDS, Tween-40, Tween-60, and Tween-80 (1% and was found stimulatory effect, respectively. Only Triton-X-100 showed a moderate inhibitory effect (5% on amylase activity. This isolate (Bacillus tequilensis RG-01 may be useful in several industrial applications owing to its thermotolerant and organic solvents and surfactants resistance characteristics.

  15. Preparation of the CNC/Ag/beeswax composites for enhancing antibacterial and water resistance properties of paper.

    Science.gov (United States)

    Liu, Kai; Liang, Hunan; Nasrallah, Joseph; Chen, Lihui; Huang, Liulian; Ni, Yonghao

    2016-05-20

    An effective method of preparing composites containing inorganic (Ag) and organic (beeswax) particles was established in this study. Ag nanoparticles were first immobilized on the cellulose nanocrystals (CNC) during the reduction of AgNO3 in the presence of CNC, then mixed with beeswax by high speed stirring. Scanning transmission electron microscopy (STEM) images indicated that Ag and beeswax particles were uniformly dispersed and stable in the network structure formed by CNC. Upon coating on a paper surface, a layer of beeswax film was evident based on scanning electron microscopy (SEM) images. The dynamic contact angle and antibacterial activity tests indicated that the contact angle of coated paper reached 113.06° and the growth inhibition of Escherichia coli increased to 99.96%, respectively, at a coating amount of 21.53 g/m(2). When applied onto paper surface by coating, the CNC/Ag/beeswax composites can impact paper with antibacterial property and improved water resistance. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Rationally engineered nanoparticles target multiple myeloma cells, overcome cell-adhesion-mediated drug resistance, and show enhanced efficacy in vivo

    International Nuclear Information System (INIS)

    Kiziltepe, T; Ashley, J D; Stefanick, J F; Qi, Y M; Alves, N J; Handlogten, M W; Suckow, M A; Navari, R M; Bilgicer, B

    2012-01-01

    In the continuing search for effective cancer treatments, we report the rational engineering of a multifunctional nanoparticle that combines traditional chemotherapy with cell targeting and anti-adhesion functionalities. Very late antigen-4 (VLA-4) mediated adhesion of multiple myeloma (MM) cells to bone marrow stroma confers MM cells with cell-adhesion-mediated drug resistance (CAM-DR). In our design, we used micellar nanoparticles as dynamic self-assembling scaffolds to present VLA-4-antagonist peptides and doxorubicin (Dox) conjugates, simultaneously, to selectively target MM cells and to overcome CAM-DR. Dox was conjugated to the nanoparticles through an acid-sensitive hydrazone bond. VLA-4-antagonist peptides were conjugated via a multifaceted synthetic procedure for generating precisely controlled number of targeting functionalities. The nanoparticles were efficiently internalized by MM cells and induced cytotoxicity. Mechanistic studies revealed that nanoparticles induced DNA double-strand breaks and apoptosis in MM cells. Importantly, multifunctional nanoparticles overcame CAM-DR, and were more efficacious than Dox when MM cells were cultured on fibronectin-coated plates. Finally, in a MM xenograft model, nanoparticles preferentially homed to MM tumors with ∼10 fold more drug accumulation and demonstrated dramatic tumor growth inhibition with a reduced overall systemic toxicity. Altogether, we demonstrate the disease driven engineering of a nanoparticle-based drug delivery system, enabling the model of an integrative approach in the treatment of MM

  17. Transgenic Cotton Plants Expressing the HaHR3 Gene Conferred Enhanced Resistance to Helicoverpa armigera and Improved Cotton Yield.

    Science.gov (United States)

    Han, Qiang; Wang, Zhenzhen; He, Yunxin; Xiong, Yehui; Lv, Shun; Li, Shupeng; Zhang, Zhigang; Qiu, Dewen; Zeng, Hongmei

    2017-08-30

    RNA interference (RNAi) has been developed as an efficient technology. RNAi insect-resistant transgenic plants expressing double-stranded RNA (dsRNA) that is ingested into insects to silence target genes can affect the viability of these pests or even lead to their death. HaHR3 , a molt-regulating transcription factor gene, was previously selected as a target expressed in bacteria and tobacco plants to control Helicoverpa armigera by RNAi technology. In this work, we selected the dsRNA- HaHR3 fragment to silence HaHR3 in cotton bollworm for plant mediated-RNAi research. A total of 19 transgenic cotton lines expressing HaHR3 were successfully cultivated, and seven generated lines were used to perform feeding bioassays. Transgenic cotton plants expressing ds HaHR3 were shown to induce high larval mortality and deformities of pupation and adult eclosion when used to feed the newly hatched larvae, and 3rd and 5th instar larvae of H. armigera . Moreover, HaHR3 transgenic cotton also demonstrated an improved cotton yield when compared with controls.

  18. Enhancement of the Wear Resistance and Microhardness of Aluminum Alloy by Nd:YaG Laser Treatment

    Directory of Open Access Journals (Sweden)

    Haitham T. Hussein

    2014-01-01

    Full Text Available Influence of laser treatment on mechanical properties, wear resistance, and Vickers hardness of aluminum alloy was studied. The specimens were treated by using Nd:YaG laser of energy 780 mj, wavelength 512 nm, and duration time 8 ns. The wear behavior of the specimens was studied for all specimens before and after treatment by Nd:YaG laser and the dry wear experiments were carried out by sing pinon-disc technique. The specimens were machined as a disk with diameter of 25 mm and circular groove in depth of 3 mm. All specimens were conducted by scanning electron microscopy (SEM, energy-dispersive X-ray florescence analysis (EDS, optical microscopy, and Vickers hardness. The results showed that the dry wear rate was decreased after laser hardening and increased Vickers hardness values by ratio of 2.4 : 1. The results showed that the values of wear rate for samples having circular grooves are less than samples without grooves after laser treatment.

  19. Self-assembled monolayer resists and nanoscale lithography of silicon dioxide thin films by chemically enhanced vapor etching (CEVE)

    Science.gov (United States)

    Pan, M.; Yun, M.; Kozicki, M. N.; Whidden, T. K.

    1996-10-01

    We report on the use of electron-beam exposed monolayers of undecylenic acid in the etch rate enhancement of silicon dioxide films in HF vapor for the formation of nanoscale features in the oxide. Variations of the etching characteristics with electron beam parameters are examined and the results analyzed in terms of proposed models of the etching mechanism. Apparent variations in the relative concentrations of etch initiator with the thermal history of the samples prior to etching provides support for the dominant etch initiator within this system as the carboxylic acid moiety bound at the oxide surface. Other variations in the etching characteristics are discussed in terms of differences in localized concentrations of hydrocarbon crosslinks and the effect that this has upon the etch initiation. The process has been employed in the production of features in silicon dioxide surface masks with sizes down to 50 nm.

  20. Sub- T g Cross-Linking of a Polyimide Membrane for Enhanced CO 2 Plasticization Resistance for Natural Gas Separation

    KAUST Repository

    Qiu, Wulin

    2011-08-09

    Decarboxylation-induced thermal cross-linking occurs at elevated temperatures (∼15 °C above glass transition temperature) for 6FDA-DAM:DABA polyimides, which can stabilize membranes against swelling and plasticization in aggressive feed streams. Despite this advantage, such a high temperature might result in collapse of substructure and transition layers in the asymmetric structure of a hollow fibers based on such a material. In this work, the thermal cross-linking of the 6FDA-DAM:DABA at temperatures much below the glass transition temperature (∼387 °C by DSC) was demonstrated. This sub-Tg cross-linking capability enables extension to asymmetric structures useful for large scale membranes. The resulting polymer membranes were characterized by swelling in known solvents for the un-cross-linked materials, TGA analysis, and permeation tests of aggressive gas feed stream at higher pressure. The annealing temperature and time clearly influence the degree of cross-linking of the membranes, and results in a slight difference in selectivity for membranes under various cross-linking conditions. Results indicate that the sub-Tg thermal cross-linking of 6FDA-DAM:DABA dense film membrane can be carried out completely even at a temperature as low as 330 °C. Permeabilities were tested for the polyimide membranes using both pure gases (He, O2, N2, CH4, CO2) and mixed gases (CO2/CH4). The selectivity of the cross-linked membrane can be maintained even under very aggressive CO2 operating conditions that are not possible without cross-linking. Moreover, the plasticization resistance was demonstrated up to 700 psia for pure CO 2 gas or 1000 psia for 50% CO2 mixed gas feeds. © 2011 American Chemical Society.