150 research outputs found

    The decline and rise of neighbourhoods: the importance of neighbourhood governance

    Get PDF
    There is a substantial literature on the explanation of neighbourhood change. Most of this literature concentrates on identifying factors and developments behind processes of decline. This paper reviews the literature, focusing on the identification of patterns of neighbourhood change, and argues that the concept of neighbourhood governance is a missing link in attempts to explain these patterns. Including neighbourhood governance in the explanations of neighbourhood change and decline will produce better explanatory models and, finally, a better view about what is actually steering neighbourhood change

    Mild Electrical Stimulation with Heat Shock Ameliorates Insulin Resistance via Enhanced Insulin Signaling

    Get PDF
    Low-intensity electrical current (or mild electrical stimulation; MES) influences signal transduction and activates phosphatidylinositol-3 kinase (PI3K)/Akt pathway. Because insulin resistance is characterized by a marked reduction in insulin-stimulated PI3K-mediated activation of Akt, we asked whether MES could increase Akt phosphorylation and ameliorate insulin resistance. In addition, it was also previously reported that heat shock protein 72 (Hsp72) alleviates hyperglycemia. Thus, we applied MES in combination with heat shock (HS) to in vitro and in vivo models of insulin resistance. Here we show that 10-min treatment with MES at 5 V (0.1 ms pulse duration) together with HS at 42°C increased the phosphorylation of insulin signaling molecules such as insulin receptor substrate (IRS) and Akt in HepG2 cells maintained in high-glucose medium. MES (12 V)+mild HS treatment of high fat-fed mice also increased the phosphorylation of insulin receptor β subunit (IRβ) and Akt in mice liver. In high fat-fed mice and db/db mice, MES+HS treatment for 10 min applied twice a week for 12–15 weeks significantly decreased fasting blood glucose and insulin levels and improved insulin sensitivity. The treated mice showed significantly lower weight of visceral and subcutaneous fat, a markedly improved fatty liver and decreased size of adipocytes. Our findings indicated that the combination of MES and HS alleviated insulin resistance and improved fat metabolism in diabetes mouse models, in part, by enhancing the insulin signaling pathway

    Expression of two barley proteinase inhibitors in tomato promotes endogenous defensive response and enhances resistance to Tuta absoluta

    Get PDF
    [EN] Background: For as long as 350 million years, plants and insects have coexisted and developed a set of relationships which affect both organisms at different levels. Plants have evolved various morphological and biochemical adaptations to cope with herbivores attacks. However, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has become the major pest threatening tomato crops worldwide and without the appropriated management it can cause production losses between 80 to 100%. Results: The aim of this study was to investigate the in vivo effect of a serine proteinase inhibitor (BTI-CMe) and a cysteine proteinase inhibitor (Hv-CPI2) from barley on this insect and to examine the effect their expression has on tomato defensive response. We found that larvae fed on the double transgenic plants showed a notable reduction in weight. Moreover, only 56% of the larvae reached the adult stage. The emerged adults showed wings deformities and reduced fertility. We also investigated the effect of proteinase inhibitors ingestion on the insect digestive enzymes. Our results showed a decrease in larval trypsin activity. Transgenes expression had no harmful effect on Nesidiocoris tenuis (Reuter) (Heteroptera: Miridae), a predator of Tuta absoluta, despite transgenic tomato plants attracted the mirid. We also found that barley cystatin expression promoted plant defense by inducing the expression of the tomato endogenous wound inducible Proteinase inhibitor 2 (Pin2) gene, increasing the production of glandular trichomes and altering the emission of volatile organic compounds. Conclusion: Our results demonstrate the usefulness of the co-expression of different proteinase inhibitors for the enhancement of plant resistance to Tuta absoluta.This work was partly supported by grants BIO2013-40747-R and AGL2014-55616-C3 from the Spanish Ministry of Economy and Competitiveness (MINECO)Hamza, R.; Pérez-Hedo, M.; Urbaneja, A.; Rambla Nebot, JL.; Granell Richart, A.; Gaddour, K.; Beltran Porter, JP.... (2018). Expression of two barley proteinase inhibitors in tomato promotes endogenous defensive response and enhances resistance to Tuta absoluta. BMC Plant Biology. 18. https://doi.org/10.1186/s12870-018-1240-6S18Oerke EC. Crop losses to pests. J Agric Sci. 2005;144(01):31.Jouanin L, Bonadé-Bottino M, Girard C, Morrot G, Giband M. Transgenic plants for insect resistance. Plant Sci. 1998;131(1):1–11.Markwick NP, Docherty LC, Phung MM, Lester MT, Murray C, Yao JL, Mitra DS, Cohen D, Beuning LL, Kutty-Amma S, et al. Transgenic tobacco and apple plants expressing biotin-binding proteins are resistant to two cosmopolitan insect pests, potato tuber moth and lightbrown apple moth, respectively. Transgenic Res. 2003;12(6):671–81.Koiwa H, Bressan RA, Hasegawa PM. Regulation of protease inhibitors and plant defense. Trends Plant Sci. 1997;2(10):379–84.Ryan CA. Protease inhibitors in plants: genes for improving defenses against insects and pathogens. Annu Rev Phytopathol. 1990;28(1):425–49.Abdeen A, Virgos A, Olivella E, Villanueva J, Aviles X, Gabarra R, Prat S. Multiple insect resistance in transgenic tomato plants over-expressing two families of plant proteinase inhibitors. Plant Mol Biol. 2005;57(2):189–202.Quilis J, López-García B, Meynard D, Guiderdoni E, San Segundo B. Inducible expression of a fusion gene encoding two proteinase inhibitors leads to insect and pathogen resistance in transgenic rice. Plant Biotechnol J. 2014;12(3):367–77.Smigocki AC, Ivic-Haymes S, Li H, Savic J. Pest protection conferred by a Beta vulgaris serine proteinase inhibitor gene. PLoS One. 2013;8(2):e57303.Mazumdar-Leighton S, Broadway RM. Transcriptional induction of diverse midgut trypsins in larval Agrotis ipsilon and Helicoverpa zea feeding on the soybean trypsin inhibitor. Insect Biochem Mol Biol. 2001;31(6–7):645–57.Oppert B, Morgan TD, Hartzer K, Kramer KJ. Compensatory proteolytic responses to dietary proteinase inhibitors in the red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae). Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology. 2005;140(1):53–8.Broadway RM. Dietary regulation of serine proteinases that are resistant to serine proteinase inhibitors. J Insect Physiol. 1997;43(9):855–74.Zhu-Salzman K, Koiwa H, Salzman R, Shade R, Ahn JE. Cowpea bruchid Callosobruchus maculatus uses a three-component strategy to overcome a plant defensive cysteine protease inhibitor. Insect Mol Biol. 2003;12(2):135–45.Oppert B, Morgan TD, Hartzer K, Lenarcic B, Galesa K, Brzin J, Turk V, Yoza K, Ohtsubo K, Kramer KJ. Effects of proteinase inhibitors on digestive proteinases and growth of the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). Comparative biochemistry and physiology Toxicology & pharmacology : CBP. 2003;134(4):481–90.Duan X, Li X, Xue Q, Abo-El-Saad M, Xu D, Wu R. Transgenic rice plants harboring an introduced potato proteinase inhibitor II gene are insect resistant. Nat Biotechnol. 1996;14(4):494–8.Pompermayer P, Lopes AR, Terra WR, Parra JRP, Falco MC, Silva-Filho MC. Effects of soybean proteinase inhibitor on development, survival and reproductive potential of the sugarcane borer, Diatraea saccharalis. Entomologia Experimentalis et Applicata. 2001;99(1):79–85.Alfonso-Rubí J, Ortego F, Castañera P, Carbonero P, Díaz I. Transgenic expression of trypsin inhibitor CMe from barley in indica and japonica rice, confers resistance to the rice weevil Sitophilus oryzae. Transgenic Res. 2003;12(1):23–31.Altpeter F, Diaz I, Mc Auslane H, Gaddour K, Carbonero P, Vasil IK. Increased insect resistance in transgenic wheat stably expressing trypsin inhibitor CMe. Mol Breed. 1999;5(1):53–63.Martinez M, Cambra I, Carrillo L, Diaz-Mendoza M, Diaz I. Characterization of the entire cystatin gene family in barley and their target cathepsin L-like cysteine-proteases, partners in the hordein mobilization during seed germination. Plant Physiol. 2009;151(3):1531–45.FAOSTAT: Food and Organization of the United Nations, statistics division. 2017.Mueller LA, Lankhorst RK, Tanksley SD, Giovannoni JJ, White R, Vrebalov J, Fei Z, van Eck J, Buels R, Mills AA, et al. A snapshot of the emerging tomato genome sequence. The Plant Genome. 2009;2(1):78–92.Ellul P, Garcia-Sogo B, Pineda B, Rios G, Roig L, Moreno V. The ploidy level of transgenic plants in agrobacterium-mediated transformation of tomato cotyledons (Lycopersicon esculentum L. mill.) is genotype and procedure dependent. Theor Appl Genet. 2003;106(2):231–8.Pino LE, Lombardi-Crestana S, Azevedo MS, Scotton DC, Borgo L, Quecini V, Figueira A, Peres LE. The Rg1 allele as a valuable tool for genetic transformation of the tomato'Micro-Tom'model system. Plant Methods. 2010;6(1):23.Sharma MK, Solanke AU, Jani D, Singh Y, Sharma AK. A simple and efficient agrobacterium-mediated procedure for transformation of tomato. J Biosci. 2009;34(3):423–33.van Eck J, Kirk DD, Walmsley AM. Tomato (Lycopersicum esculentum). Agrobacterium Protocols. 2006:459–74.Dan Y, Yan H, Munyikwa T, Dong J, Zhang Y, Armstrong CL. MicroTom—a high-throughput model transformation system for functional genomics. Plant Cell Rep. 2006;25(5):432–41.Pearce G, Strydom D, Johnson S, Ryan CA. A polypeptide from tomato leaves induces wound-inducible proteinase inhibitor proteins. Science. 1991;253(5022):895–9.Farmer EE, Ryan CA. Interplant communication: airborne methyl jasmonate induces synthesis of proteinase inhibitors in plant leaves. Proc Natl Acad Sci. 1990;87(19):7713–6.Bosch M, Wright LP, Gershenzon J, Wasternack C, Hause B, Schaller A, Stintzi A. Jasmonic acid and its precursor 12-oxophytodienoic acid control different aspects of constitutive and induced herbivore defenses in tomato. Plant Physiol. 2014;166(1):396–410.Christensen SA, Nemchenko A, Borrego E, Murray I, Sobhy IS, Bosak L, DeBlasio S, Erb M, Robert CA, Vaughn KA. The maize lipoxygenase, ZmLOX10, mediates green leaf volatile, jasmonate and herbivore-induced plant volatile production for defense against insect attack. Plant J. 2013;74(1):59–73.Boughton AJ, Hoover K, Felton GW. Methyl jasmonate application induces increased densities of glandular trichomes on tomato, Lycopersicon esculentum. J Chem Ecol. 2005;31(9):2211–6.Li L, Zhao Y, McCaig BC, Wingerd BA, Wang J, Whalon ME, Pichersky E, Howe GA. The tomato homolog of CORONATINE-INSENSITIVE1 is required for the maternal control of seed maturation, jasmonate-signaled defense responses, and glandular trichome development. Plant Cell. 2004;16(1):126–43.Peiffer M, Tooker JF, Luthe DS, Felton GW. Plants on early alert: glandular trichomes as sensors for insect herbivores. New Phytol. 2009;184(3):644–56.Bryant J, Green TR, Gurusaddaiah T, Ryan CA. Proteinase inhibitor II from potatoes: isolation and characterization of its protomer components. Biochemistry. 1976;15(16):3418–24.Johnson R, Narvaez J, An G, Ryan C. Expression of proteinase inhibitors I and II in transgenic tobacco plants: effects on natural defense against Manduca sexta larvae. Proc Natl Acad Sci. 1989;86(24):9871–5.Klopfenstein NB, Allen KK, Avila FJ, Heuchelin SA, Martinez J, Carman RC, Hall RB, Hart ER, McNabb HS. Proteinase inhibitor II gene in transgenic poplar: chemical and biological assays. Biomass Bioenergy. 1997;12(4):299–311.Dicke M, Takabayashi J, Posthumus MA, Schütte C, Krips OE. Plant—Phytoseiid interactions mediated by herbivore-induced plant volatiles: variation in production of cues and in responses of predatory mites. Exp Appl Acarol. 1998;22(6):311–33.Turlings T, Loughrin JH, Mccall PJ, Röse U, Lewis WJ, Tumlinson JH. How caterpillar-damaged plants protect themselves by attracting parasitic wasps. Proc Natl Acad Sci. 1995;92(10):4169–74.Levin DA. The role of trichomes in plant defense. Q Rev Biol. 1973;48(1, Part 1):3–15.Traw BM, Dawson TE. Differential induction of trichomes by three herbivores of black mustard. Oecologia. 2002;131(4):526–32.Handley R, Ekbom B, Ågren J. Variation in trichome density and resistance against a specialist insect herbivore in natural populations of Arabidopsis thaliana. Ecological Entomology. 2005;30(3):284–92.Valverde P, Fornoni J, NÚÑez-Farfán J. Defensive role of leaf trichomes in resistance to herbivorous insects in Datura stramonium. J Evol Biol. 2001;14(3):424–32.Elle E, Hare J. Environmentally induced variation in floral traits affects the mating system in Datura wrightii. Funct Ecol. 2002;16(1):79–88.Agrawal AA. Benefits and costs of induced plant defense for Lepidium virginicum (Brassicaceae). Ecology. 2000;81(7):1804–13.Dalin P, Björkman C. Adult beetle grazing induces willow trichome defence against subsequent larval feeding. Oecologia. 2003;134(1):112–8.Campos MR, Biondi A, Adiga A, Guedes RN, Desneux N. From the western Palaearctic region to beyond: Tuta absoluta 10 years after invading Europe. J Pest Sci. 2017:1–10.Desneux N, Wajnberg E, Wyckhuys KA, Burgio G, Arpaia S, Narváez-Vasquez CA, González-Cabrera J, Ruescas DC, Tabone E, Frandon J. Biological invasion of European tomato crops by Tuta absoluta: ecology, geographic expansion and prospects for biological control. J Pest Sci. 2010;83(3):197–215.Urbaneja A, Montón H, Mollá O. Suitability of the tomato borer Tuta absoluta as prey for Macrolophus pygmaeus and Nesidiocoris tenuis. J Appl Entomol. 2009;133(4):292–6.Pérez-Hedo M, Urbaneja A. Prospects for predatory mirid bugs as biocontrol agents of aphids in sweet peppers. J Pest Sci. 2015;88(1):65–73.Hewitt E. The composition of the nutrient solution. Sand and water culture methods used in the study of plant Nutrition. 1966:187–246.Karimi M, Inzé D, Depicker A. GATEWAY™ vectors for agrobacterium-mediated plant transformation. Trends Plant Sci. 2002;7(5):193–5.Martín-Trillo M, Grandío EG, Serra F, Marcel F, Rodríguez-Buey ML, Schmitz G, Theres K, Bendahmane A, Dopazo H, Cubas P. Role of tomato BRANCHED1-like genes in the control of shoot branching. Plant J. 2011;67(4):701–14.Vargas C. Observations on the bionomics and natural enemies of the tomato moth, Gnorimoschema absoluta (Meyrick)(Lep. Gelechiidae). Idesia. 1970;1:75–110.Mollá O, Biondi A, Alonso-Valiente M, Urbaneja A. A comparative life history study of two mirid bugs preying on Tuta absoluta and Ephestia kuehniella eggs on tomato crops: implications for biological control. BioControl. 2014;59(2):175–83.Abbot C. Solar variation and the weather. Science (New York, NY). 1925;62(1605):307.Bradford MM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Anal Biochem. 1976;72(1–2):248–54.Bouagga S, Urbaneja A, Rambla JL, Granell A, Pérez-Hedo M. Orius laevigatus strengthens its role as a biological control agent by inducing plant defenses. J Pest Sci. 2017:1–10.Hilder VA, Gatehouse AM, Sheerman SE, Barker RF, Boulter D. A novel mechanism of insect resistance engineered into tobacco. Nature. 1987;330(6144):160–3.Saikia K, Kalita J, Saikia PK. Biology and life cycle generations of common crow–Euploea core core Cramer (Lepidoptera: Danainae) on Hemidesmus indica host plant. Int J NeBIO. 2010;1(3):28–37.Srinivasan A, Giri AP, Gupta VS. Structural and functional diversities in lepidopteran serine proteases. Cellular & molecular biology letters. 2006;11(1):132.Tamhane VA, Chougule NP, Giri AP, Dixit AR, Sainani MN, Gupta VS. In vivo and in vitro effect of Capsicum annum proteinase inhibitors on Helicoverpa armigera gut proteinases. Biochimica et Biophysica Acta (BBA)-General Subjects. 2005;1722(2):156–67.Telang M, Srinivasan A, Patankar A, Harsulkar A, Joshi V, Damle A, Deshpande V, Sainani M, Ranjekar P, Gupta G. Bitter gourd proteinase inhibitors: potential growth inhibitors of Helicoverpa armigera and Spodoptera litura. Phytochemistry. 2003;63(6):643–52.Damle MS, Giri AP, Sainani MN, Gupta VS. Higher accumulation of proteinase inhibitors in flowers than leaves and fruits as a possible basis for differential feeding preference of Helicoverpa armigera on tomato (Lycopersicon esculentum mill, cv. Dhanashree). Phytochemistry. 2005;66(22):2659–67.De Leo F, Bonadé-Bottino MA, Ceci LR, Gallerani R, Jouanin L. Opposite effects on spodoptera littoralis larvae of high expression level of a trypsin proteinase inhibitor in transgenic plants. Plant Physiol. 1998;118(3):997–1004.Rahbé Y, Ferrasson E, Rabesona H, Quillien L. Toxicity to the pea aphid Acyrthosiphon pisum of anti-chymotrypsin isoforms and fragments of Bowman–Birk protease inhibitors from pea seeds. Insect Biochem Mol Biol. 2003;33(3):299–306.Luo M, Ding L-W, Ge Z-J, Wang Z-Y, Hu B-L, Yang X-B, Sun Q-Y, Xu Z-F. The characterization of SaPIN2b, a plant trichome-localized proteinase inhibitor from Solanum americanum. Int J Mol Sci. 2012;13(11):15162–76.Dalin P, Ågren J, Björkman C, Huttunen P, Kärkkäinen K. Leaf trichome formation and plant resistance to herbivory. In: Dordrecht SA, editor. Induced plant resistance to herbivory. Netherlands: Springer; 2008. p. 89–105.Gonzáles WL, Negritto MA, Suárez LH, Gianoli E. Induction of glandular and non-glandular trichomes by damage in leaves of Madia sativa under contrasting water regimes. Acta Oecol. 2008;33(1):128–32.Luo M, Wang Z, Li H, Xia K-F, Cai Y, Xu Z-F. Overexpression of a weed (Solanum americanum) proteinase inhibitor in transgenic tobacco results in increased glandular trichome density and enhanced resistance to Helicoverpa armigera and Spodoptera litura. Int J Mol Sci. 2009;10(4):1896–910.Björkman C, Dalin P, Ahrné K. Leaf trichome responses to herbivory in willows: induction, relaxation and costs. New Phytol. 2008;179(1):176–84.Duffey S. Plant glandular trichomes: their partial role in defence against insects. Insects and the plant surface. London: Edward Arnold; 1986. p. 151–72.James DG. Further field evaluation of synthetic herbivore-induced plan volatiles as attractants for beneficial insects. J Chem Ecol. 2005;31(3):481–95.Naselli M, Zappalà L, Gugliuzzo A, Garzia GT, Biondi A, Rapisarda C, Cincotta F, Condurso C, Verzera A, Siscaro G. Olfactory response of the zoophytophagous mirid Nesidiocoris tenuis to tomato and alternative host plants. Arthropod Plant Interact. 2017;11(2):121–31.Tholl D. Biosynthesis and biological functions of terpenoids in plants. Advances in Biochemical Engineering and Biotechnology. 2015;148:63-106.Lange BM, Rujan T, Martin W, Croteau R. Isoprenoid biosynthesis: the evolution of two ancient and distinct pathways across genomes. Proc Natl Acad Sci. 2000;97(24):13172–7.Dudareva N, Klempien A, Muhlemann JK, Kaplan I. Biosynthesis, function and metabolic engineering of plant volatile organic compounds. New Phytol. 2013;198(1):16–32.Razal RA, Ellis S, Singh S, Lewis NG, Towers GHN. Nitrogen recycling in phenylpropanoid metabolism. Phytochemistry. 1996;41(1):31–5.Effmert U, Große J, Röse US, Ehrig F, Kägi R, Piechulla B. Volatile composition, emission pattern, and localization of floral scent emission in Mirabilis jalapa (Nyctaginaceae). Am J Bot. 2005;92(1):2–12.Guterman I, Masci T, Chen X, Negre F, Pichersky E, Dudareva N, Weiss D, Vainstein A. Generation of phenylpropanoid pathway-derived volatiles in transgenic plants: rose alcohol acetyltransferase produces phenylethyl acetate and benzyl acetate in petunia flowers. Plant Mol Biol. 2006;60(4):555–63.Vogel JT, Tan B-C, McCarty DR, Klee HJ. The carotenoid cleavage dioxygenase 1 enzyme has broad substrate specificity, cleaving multiple carotenoids at two different bond positions. J Biol Chem. 2008;283(17):11364–73.Colquhoun TA, Kim JY, Wedde AE, Levin LA, Schmitt KC, Schuurink RC, Clark DG. PhMYB4 fine-tunes the floral volatile signature of petunia×hybrida through PhC4H. J Exp Bot. 2011;62(3):1133–43.Kolosova N, Gorenstein N, Kish CM, Dudareva N. Regulation of circadian methyl benzoate emission in diurnally and nocturnally emitting plants. Plant Cell. 2001;13(10):2333–47.Maeda H, Shasany AK, Schnepp J, Orlova I, Taguchi G, Cooper BR, Rhodes D, Pichersky E, Dudareva N. RNAi suppression of arogenate dehydratase1 reveals that phenylalanine is synthesized predominantly via the arogenate pathway in petunia petals. Plant Cell. 2010;22(3):832–49.Lerdau M, Gray D. Ecology and evolution of light-dependent and light-independent phytogenic volatile organic carbon. New Phytol. 2003;157(2):199–211.Martin DM, Gershenzon J, Bohlmann J. Induction of volatile terpene biosynthesis and diurnal emission by methyl jasmonate in foliage of Norway spruce. Plant Physiol. 2003;132(3):1586–99.van Doorn WG, Woltering EJ. Physiology and molecular biology of petal senescence. J Exp Bot. 2008;59(3):453–80

    Carbon Nanotubes in Tissue Engineering

    Get PDF
    For their peculiar features carbon nanotubes (CNTs) are emerging in many areas of nanotechnology applications. CNT-based technology has been increasingly proposed for biomedical applications, to develop biomolecule nanocarriers, bionanosensors and smart material for tissue engineering purposes. In the following chapter this latter application will be explored, describing why CNTs can be considered an ideal material able to support and boost the growth and the proliferation of many kind of tissues

    Guidelines for the use of chest radiographs in community-acquired pneumonia in children and adolescents

    Get PDF
    © 2017, The Author(s). National guidance from the United Kingdom and the United States on community-acquired pneumonia in children states that chest radiographs are not recommended routinely in uncomplicated cases. The main reason in the ambulatory setting is that there is no evidence of a substantial impact on clinical outcomes. However clinical practice and adherence to guidance is multifactorial and includes the clinical context (developed vs. developing world), the confidence of the attending physician, the changing incidence of complications (according to the success of immunisation programs), the availability of alternative imaging (and its relationship to perceived risks of radiation) and the reliability of the interpretation of imaging. In practice, chest radiographs are performed frequently for suspected pneumonia in children. Time pressures facing clinicians at the front line, difficulties in distinguishing which children require admission, restricted bed numbers for admissions, imaging-resource limitations, perceptions regarding risk from procedures, novel imaging modalities and the probability of other causes for the child’s presentation all need to be factored into a guideline. Other drivers that often weigh in, depending on the setting, include cost-effectiveness and the fear of litigation. Not all guidelines designed for the developed world can therefore be applied to the developing world, and practice guidelines require regular review in the context of new information. In addition, radiologists must improve radiographic diagnosis of pneumonia, reach consensus on the interpretive terminology that clarifies their confidence regarding the presence of pneumonia and act to replace one imaging technique with another whenever there is proof of improved accuracy or reliability

    Membrane assisted and temperature controlled on-line evaporative concentration for microfluidics

    Full text link
    A membrane evaporation concentrator for continuous flow conditions is introduced. The membrane evaporation concentrator provides nearly 30-fold concentration in less than 60 min whilst maintaining solute integrity under different sub-ambient pressure conditions and mild temperatures. To better understand the performance of the concentrator, a theoretical model was developed using caffeine as a model analyte, and used to predict the concentration performance of three target analytes at different conditions. An exponential relationship exists between temperature and concentration factor. By using the model it was determined that a 10-fold concentration (±0.5) can be performed at 56.72 ± 0.07 °C and at a flow rate of 10 μL min−1. Altogether, the model provides a better understanding of the process and ease of application in a wide variety of analytical methods. This work demonstrates that it is possible to obtain high concentrations with a continuously flowing fluid when temperature is precisely controlled and in times that are reasonable compared to existing evaporation concentration procedures
    corecore