Molecular epidemiology of clinical isolates of Pseudomonas aeruginosa isolated from horses in Ireland

Clinical isolates (n = 63) of Pseudomonas aeruginosa obtained from various sites in 63 horses were compared using ERIC2 RAPD PCR to determine their genetic relatedness. Resulting banding patterns (n = 24 genotypes) showed a high degree of genetic heterogeneity amongst all isolates examined, indicating a relative non-clonal relationship between isolates from these patients, employing this genotyping technique. This study characterised 63 clinical isolates into 24 distinct genotypes, with the largest cluster (genotype E) accounting for 10/63 (15.9%) of the isolates. ERIC2 RAPD PCR proved to be a highly discriminatory molecular typing tool of P. aeruginosa in isolates recovered from horses. With the adoption of several controls to aid reproducibility, this technique may be useful as an alternative to PFGE, particularly in epidemiological investigations of outbreaks where speed may be a significant parameter. This is the first report of clonal heterogeneity amongst P. aeruginosa from horses and demonstrated that ERIC RAPD PCR is a rapid method for the examination of this species in horses, which may be useful in outbreak analysis

Magnetic field dependence of superconducting energy gaps in YNi2B2C: Evidence of multiband superconductivity

We present results of in field directional point contact spectroscopy (DPCS) study in the quaternary borocarbide superconductor YNi2B2C, which is characterized by a highly anisotropic superconducting gap function. For I||a, the superconducting energy gap (D), decreases linearly with magnetic field and vanishes around 3.25T which is well below the upper critical field (Hc2~6T) measured at the same temperature (2.2K). For I||c, on the other hand, D decreases weakly with magnetic field but the broadening parameter (G) increases rapidly with magnetic field with the absence of any resolvable feature above 3.5T. From an analysis of the field variation of energy gaps and the zero bias density of states we show that the unconventional gap function observed in this material could originate from multiband superconductivity.Comment: 19 pages including figures (final version

Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides

In this work we have developed polymeric materials from epoxidized vegetable oils in order to obtain materials with excellent mechanical properties for use as green matrix composites. Epoxidized soybean oil (ESO), epoxidized linseed oil (ELO) and different mixtures of the two oils were used to produce the polymers. Phthalic anhydride (17 mol%) and maleic anhydride (83 mol%) which has a eutectic reaction temperature of 48 °C were used as crosslinking agents while benzyl dimethyl amine (BDMA) and ethylene glycol were used as the catalyst and initiator, respectively. The results showed that samples 100ELO and 80ELO20ESO could be used as a matrix in green composites because they demonstrated good mechanical properties. © 2012 AOCS (outside the USA).This work is part of the project IPT-310000-2010-037,''ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character'' funded by the "Ministerio de Ciencia e Innovacion", with financial aid of 189,540.20 EUR, within the "Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica 2008-2011" and funded by the European Union through FEDER funds, Technology Fund 2007-2013, Operational Programme on R + D + i for and on behalf of the companies.Samper Madrigal, MD.; Fombuena Borrás, V.; Boronat Vitoria, T.; García Sanoguera, D.; Balart Gimeno, RA. (2012). Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides. Journal of the American Oil Chemists' Society. 89(8):1521-1528. https://doi.org/10.1007/s11746-012-2041-yS15211528898Averous L (2004) Biodegradable multiphase systems based on plasticized starch: a review. J Macromol Sci Polym Rev C44:231–274Bledzki AK, Jaszkiewicz A (2010) Mechanical performance of biocomposites based on PLA and PHBV reinforced with natural fibres—a comparative study to PP. Compos Sci Technol 70:1687–1696Raquez JM, Deleglise M, Lacrampe MF, Krawczak P (2010) Thermosetting (bio)materials derived from renewable resources: a critical review. Prog Polym Sci 35:487–509Charlet K, Jernot JP, Gomina M, Bizet L, Breard J (2010) Mechanical properties of flax fibers and of the derived unidirectional composites. J Compos Mater 44:2887–2896Barreto ACH, Esmeraldo MA, Rosa DS, Fechine PBA, Mazzetto SE (2010) Cardanol biocomposites reinforced with jute fiber: microstructure, biodegradability, and mechanical properties. Polym Compos 31:1928–1937Thakur VK, Singha AS (2010) Physico-chemical and mechanical characterization of natural fibre reinforced polymer composites. Iran Polym J 19:3–16Schmitz WR, Wallace JG (1954) Epoxidation of methyl oleate with hydrogen peroxide. J Am Oil Chem Soc 31:363–365La Scala J, Wool RP (2002) Effect of FA composition on epoxidation kinetics of TAG. J Am Oil Chem Soc 79:373–378de Espinosa LM, Ronda JC, Galia M, Cadiz V (2008) A new enone-containing triglyceride derivative as precursor of thermosets from renewable resources. J Polym Sci Pol Chem 46:6843–6850Gerbase AE, Petzhold CL, Costa APO (2002) Dynamic mechanical and thermal behavior of epoxy resins based on soybean oil. J Am Oil Chem Soc 79:797–802Boquillon N, Fringant C (2000) Polymer networks derived from curing of epoxidised linseed oil: influence of different catalysts and anhydride hardeners. Polymer 41:8603–8613Montserrat S, Flaque C, Calafell M, Andreu G, Malek J (1995) Influence of the accelerator concentration on the curing reaction of an epoxy-anhydride system. Thermochim Acta 269:213–229Zacharuk M, Becker D, Coelho LAF, Pezzin SH (2011) Study of the reaction between polyethylene glycol and epoxy resins using N,N-dimethylbenzylamine as catalyst. Polimeros 21:73–77Lozada Z, Suppes GJ, Tu YC, Hsieh FH (2009) Soy-based polyols from oxirane ring opening by alcoholysis reaction. J Appl Polym Sci 113:2552–256

Study of the properties of thermoset materials derived from epoxidized soybean oil and protein fillers

[EN] Novel bio-based thermoset formulations were prepared by using epoxidized soybean oil (ESBO), nadic methyl anhydride as a hardener and with different types of proteins as fillers. In the first part of the study, the effect of the protein-type (wheat gluten, soy protein, casein and ovalbumin) on cured ESBO materials was investigated. Thermal and mechanical properties were characterized by flexural tests, Shore D hardness, Charpy impact tests, Vicat softening temperature and heat deflection temperature. In addition, a study of the morphology of fractured surfaces by scanning electron microscopy was carried out. In general, the addition of protein-based fillers improved the mechanical and thermal properties. It was found that the highest increase of thermal and mechanical properties was achieved by ovalbumin. In the second part of the work, the effect of the total amount of ovalbumin filler was studied. Bio-based thermoset materials from ESBO and 15 wt % ovalbumin improved flexural modulus more than 150 % when compared to the unfilled material. Similar evolution was observed for other mechanical properties. Moreover, the brittleness of this composition was the minimum from the studied systems. A direct relationship between energy absorption capacity and morphologies of the failure surface was evidenced by SEM.This work is a part of the project IPT-310000-2010-037,"ECOTEXCOMP: Research and development of textile structures useful as reinforcement of composite materials with marked ecological character" funded by the "Ministerio de Ciencia e Innovacion", with an aid of 189540.20 euros, within the "Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica 2008-2011" and funded by the European Union through FEDER funds, Technology Fund 2007-2013, "Operational Programme on R+D+I for and on behalf of the companies". Also, Generalitat Valenciana ACOMP/2012/087 is acknowledged for financial support.Fombuena Borrás, V.; Sánchez Nacher, L.; Samper Madrigal, MD.; Juárez Varón, D.; Balart Gimeno, RA. (2013). Study of the properties of thermoset materials derived from epoxidized soybean oil and protein fillers. Journal of the American Oil Chemists' Society. 90(3):449-457. https://doi.org/10.1007/s11746-012-2171-2S449457903Alonso MV, Oliet M, Garcia J, Rodriguez F, Echeverria J (2006) Gelation and isoconversional kinetic analysis of lignin-phenol-formaldehyde resol resins cure. Chem Eng J 122:159–166Altuna FI, Esposito LH, Ruseckaite RA, Stefani PM (2011) Thermal and mechanical properties of anhydride-cured epoxy resins with different contents of bio-based epoxidized soybean oil. J Appl Polym Sci 120:789–798Boquillon N, Fringant C (2000) Polymer networks derived from curing of epoxidised linseed oil: influence of different catalysts and anhydride hardeners. Polymer 41:8603–8613Boquillon N, Elbez G, Schonfeld U (2004) Properties of wheat straw particleboards bonded with different types of resin. J Wood Sci 50:230–235Chakrapani S, Crivello JV (1998) Synthesis and photoinitiated cationic polymerization of epoxidized castor oil and its derivatives. J Macromol Sci-Pure Appl Chem A35:1–20Chen F, Zhang JW (2009) A new approach for morphology control of poly(butylene adipate-co-terephthalate) and soy protein blends. Polymer 50:3770–3777Cuq B, Contard N, Guilbert S (1998) Proteins as agricultural polymers for packaging production. Am Assoc Cereal Chem 75:1–9Czub P (2006) Application of modified natural oils as reactive diluents for epoxy resins. Macromol Symp 242:60–64DdS Martini, Braga BA, Samios D (2009) On the curing of linseed oil epoxidized methyl esters with different cyclic dicarboxylic anhydrides. Polymer 50:2919–2925Dogan E, Kuesefoglu S (2008) Synthesis and in situ foaming of biodegradable malonic acid ESO polymers. J Appl Polym Sci 110:1129–1135Espinosa-Perez J, Wiesenborn DP, Tostenson K, Ulven CA, Tatlari M (2007) Preparation and partial characterization of canola-based epoxy resins for bio-based plastic composites. ASABE Annual International Meeting, 076079, Minneapolis, MNJin H, Zhang L, Chen F (2003) Effects of lignin as a filler on properties of soy protein plastics. I Lignosulfonate. J Appl Polym Sci 88:3284–3290Liu ZS, Erhan SZ, Calvert PD (2007) Solid freeform fabrication of epoxidized soybean oil/epoxy composite with bis or polyalkyleneamine curing agents. Compos Part A Appl Sci Manuf 38:87–93Matejka L, Lovy J, Pokorny S, Bouchal K, Dusek K (1983) Curing epoxy-resins with anhydrides—model reactions and reaction-mechanism. J Polym Sci Part A Polym Chem 21:2873–2885Miyagawa H, Mohanty AK, Drzal LT, Misra M (2005) Nanocomposites from bio-based epoxy and single-wall carbon nanotubes: synthesis, and mechanical and thermo-physical properties evaluation. Nanotechnology 16:118–124Mohamed A, Finkenstadt VL, Gordon SH, Palmquist DE (2010) Thermal and mechanical properties of compression-molded pMDI-reinforced PCL/gluten composites. J Appl Polym Sci 118:2778–2790Montero de Espinosa L, Ronda JC, Galià M, Cádiz V (2008) A new enone-containing triglyceride derivative as precursor of thermosets from renewable resources. J Polym Sci Part A Polym Chem 46:6843–6850Park SJ, Jin FL, Lee JR (2004) Synthesis and thermal properties of epoxidized vegetable oil. Macromol Rapid Commun 25:724–727Pfister DP, Baker RJ, Henna HP, Lu Y, Larock CR (2008) Preparation and properties of tung oil-based composites using spent germ as a natural filler. J Appl Polym Sci 108:3618–3625Reiznautt QB, Garcia ITS, Samios D (2009) Oligoesters and polyesters produced by the curing of sunflower oil epoxidized biodiesel with cis-cyclohexane dicarboxylic anhydride: synthesis and characterization. Mater Sci Eng C Mater Biol Appl 29:2302–2311Rüsch Gen Klaas M, Warwel S (1999) Complete and partial epoxidation of plant oils by lipase-catalyzed perhydrolysis. Ind Crops Prod 9:125–132Sailaja RRN, Girija BG, Madras G, Balasubramanian N (2008) Effect of compatibilization on mechanical and thermal properties of polypropylene—soy flour composites. J Mater Sci 43:64–67Samper MD, Fombuena V, Boronat T, García-Sanoguera D, Balart R (2012) Thermal and mechanical characterization of epoxy resins (ELO and ESO) cured with anhydrides. J Am Oil Chem Soc 89(8):1521–1528Sharma S (2008) Fabrication and characterization of polymer blends and composites derived from biopolymers. Philosophy Materials Science and Engineering. Graduate School of Clemson University, ClemsonSharma BK, Liu Z, Adhvaryu A, Erhan SZ (2008) One-pot synthesis of chemically modified vegetable oils. J Agric Food Chem 56:3049–3056Sue HJ, Wang S, Jane J (1997) Morphology and mechanical behaviour of engineering soy plastics. J Polym 38:5035Wang S, Sue HJ, Jane J (1996) Effects of polyhydric alcohols on the mechanical properties of soy protein plastics. J Macromol Sci Pure Appl Chem A33:557–569Wazzan AA, Al-Turaif HA, Abdelkader AF (2006) Influence of submicron TiO2 particles on the mechanical properties and fracture characteristics of cured epoxy resin. Polym Plastics Technol Eng 45:1155–116

PyroTyping, a novel pyrosequencing-based assay for Mycobacterium tuberculosis genotyping

We developed a novel method, PyroTyping, for discrimination of Mycobacterium tuberculosis isolates combining pyrosequencing and IS6110 polymorphism. A total of 100 isolates were analysed with IS6110-restriction fragment length polymorphism (RFLP), spoligotyping, mycobacterial interspersed repetitive units - variable number tandem repeats (MIRU-VNTR), and PyroTyping. PyroTyping results regarding clustering or discrimination of the isolates were highly concordant with the other typing methods performed. PyroTyping is more rapid than RFLP and presents the same discriminatory power, thus, it may be useful for taking timely decisions for tuberculosis control

DNA restriction fragment length polymorphism analysis of Mycobacterium tuberculosis isolates from HIV-seropositive and HIV-seronegative patients in Kampala, Uganda

<p>Abstract</p> <p>Background</p> <p>The identification and differentiation of strains of <it>Mycobacterium tuberculosis </it>by DNA fingerprinting has provided a better understanding of the epidemiology and tracing the transmission of tuberculosis. We set out to determine if there was a relationship between the risk of belonging to a group of tuberculosis patients with identical mycobacterial DNA fingerprint patterns and the HIV sero-status of the individuals in a high TB incidence peri-urban setting of Kampala, Uganda.</p> <p>Methods</p> <p>One hundred eighty three isolates of <it>Mycobacterium tuberculosis </it>from 80 HIV seropositive and 103 HIV seronegative patients were fingerprinted by standard IS<it>6110</it>-RFLP. Using the BioNumerics software, strains were considered to be clustered if at least one other patient had an isolate with identical RFLP pattern.</p> <p>Results</p> <p>One hundred and eighteen different fingerprint patterns were obtained from the 183 isolates. There were 34 clusters containing 54% (99/183) of the patients (average cluster size of 2.9), and a majority (96.2%) of the strains possessed a high copy number (≥ 5 copies) of the IS<it>6110 </it>element. When strains with <5 bands were excluded from the analysis, 50.3% (92/183) were clustered, and there was no difference in the level of diversity of DNA fingerprints observed in the two sero-groups (adjusted odds ratio [aOR] 0.85, 95%CI 0.46–1.56, <it>P </it>= 0.615), patients aged <40 years (aOR 0.53, 95%CI 0.25–1.12, <it>P </it>= 0.100), and sex (aOR 1.12, 95%CI 0.60–2.06, <it>P </it>= 0.715).</p> <p>Conclusion</p> <p>The sample showed evidence of a high prevalence of recent transmission with a high average cluster size, but infection with an isolate with a fingerprint found to be part of a cluster was not associated with any demographic or clinical characteristics, including HIV status.</p

The Dependence of the Superconducting Transition Temperature of Organic Molecular Crystals on Intrinsically Non-Magnetic Disorder: a Signature of either Unconventional Superconductivity or Novel Local Magnetic Moment Formation

We give a theoretical analysis of published experimental studies of the effects of impurities and disorder on the superconducting transition temperature, T_c, of the organic molecular crystals kappa-ET_2X and beta-ET_2X (where ET is bis(ethylenedithio)tetrathiafulvalene and X is an anion eg I_3). The Abrikosov-Gorkov (AG) formula describes the suppression of T_c both by magnetic impurities in singlet superconductors, including s-wave superconductors and by non-magnetic impurities in a non-s-wave superconductor. We show that various sources of disorder lead to the suppression of T_c as described by the AG formula. This is confirmed by the excellent fit to the data, the fact that these materials are in the clean limit and the excellent agreement between the value of the interlayer hopping integral, t_perp, calculated from this fit and the value of t_perp found from angular-dependant magnetoresistance and quantum oscillation experiments. If the disorder is, as seems most likely, non-magnetic then the pairing state cannot be s-wave. We show that the cooling rate dependence of the magnetisation is inconsistent with paramagnetic impurities. Triplet pairing is ruled out by several experiments. If the disorder is non-magnetic then this implies that l>=2, in which case Occam's razor suggests that d-wave pairing is realised. Given the proximity of these materials to an antiferromagnetic Mott transition, it is possible that the disorder leads to the formation of local magnetic moments via some novel mechanism. Thus we conclude that either kappa-ET_2X and beta-ET_2X are d-wave superconductors or else they display a novel mechanism for the formation of localised moments. We suggest systematic experiments to differentiate between these scenarios.Comment: 18 pages, 5 figure

A Comprehensive MRI Study of Over 2000 Subjects

The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes. Here, we studied the characteristics of IHI in a community-based sample of 2008 subjects of the IMAGEN database and their association with extra-hippocampal anatomical variations. The presence of IHI was assessed on T1-weighted anatomical magnetic resonance imaging (MRI) using visual criteria. We assessed the association of IHI with other anatomical changes throughout the brain using automatic morphometry of cortical sulci. We found that IHI were much more frequent in the left hippocampus (left: 17%, right: 6%, χ2−test, p < 10−28). Compared to subjects without IHI, subjects with IHI displayed morphological changes in several sulci located mainly in the limbic lobe. Our results demonstrate that IHI are a common left-sided phenomenon in normal subjects and that they are associated with morphological changes outside the medial temporal lobe

The Individual Blood Cell Telomere Attrition Rate Is Telomere Length Dependent

Age-associated telomere shortening is a well documented feature of peripheral blood cells in human population studies, but it is not known to what extent these data can be transferred to the individual level. Telomere length (TL) in two blood samples taken at ∼10 years interval from 959 individuals was investigated using real-time PCR. TL was also measured in 13 families from a multigenerational cohort. As expected, we found an age-related decline in TL over time (r = –0.164, P<0.001, n = 959). However, approximately one-third of the individuals exhibited a stable or increased TL over a decade. The individual telomere attrition rate was inversely correlated with initial TL at a highly significant level (r = –0.752, P<0.001), indicating that the attrition rate was most pronounced in individuals with long telomeres at baseline. In accordance, the age-associated telomere attrition rate was more prominent in families with members displaying longer telomeres at a young age (r = –0.691, P<0.001). Abnormal blood TL has been reported at diagnosis of various malignancies, but in the present study there was no association between individual telomere attrition rate or prediagnostic TL and later tumor development. The collected data strongly suggest a TL maintenance mechanism acting in vivo, providing protection of short telomeres as previously demonstrated in vitro. Our findings might challenge the hypothesis that individual TL can predict possible life span or later tumor development