Clinically-relevant threshold of preformed donor-specific anti-HLA antibodies in kidney transplantation.

BACKGROUND: Pretransplant anti-HLA donor-specific antibodies (DSA) are recognized as a risk factor for acute antibody-mediated rejection (AMR) in kidney transplantation. The predictive value of C4d-fixing capability by DSA or of IgG DSA subclasses for acute AMR in the pretransplant setting has been recently studied. In addition DSA strength assessed by mean fluorescence intensity (MFI) may improve risk stratification. We aimed to analyze the relevance of preformed DSA and of DSA MFI values. METHODS: 280 consecutive patients with negative complement-dependent cytotoxicity crossmatches received a kidney transplant between 01/2008 and 03/2014. Sera were screened for the presence of DSA with a solid-phase assays on a Luminex flow analyzer, and the results were correlated with biopsy-proven acute AMR in the first year and survival. RESULTS: Pretransplant anti-HLA antibodies were present in 72 patients (25.7%) and 24 (8.6%) had DSA. There were 46 (16.4%) acute rejection episodes, 32 (11.4%) being cellular and 14 (5.0%) AMR. The incidence of acute AMR was higher in patients with pretransplant DSA (41.7%) than in those without (1.6%) (p<0.001). The median cumulative MFI (cMFI) of the group DSA+/AMR+ was 5680 vs 2208 in DSA+/AMR- (p=0.058). With univariate logistic regression a threshold value of 5280 cMFI was predictive for acute AMR. DSA cMFI's ability to predict AMR was also explored by ROC analysis. AUC was 0.728 and the best threshold was a cMFI of 4340. Importantly pretransplant DSA>5280 cMFI had a detrimental effect on 5-year graft survival. CONCLUSIONS: Preformed DSA cMFI values were clinically-relevant for the prediction of acute AMR and graft survival in kidney transplantation. A threshold of 4300-5300 cMFI was a significant outcome predictor.

Características fisico-químicas e sensoriais da carne de bubalinos Murrah abatidos em diferentes períodos de confinamento

Objetivou-se avaliar as características físicas, químicas e sensoriais da carne de búfalos abatidos em diferentes períodos de confinamento. Foram utilizados 20 bubalinos da raça Murrah, castrados, descornados, com idade média inicial de 15 meses, abatidos aos 75, 100, 125 ou 150 dias de confinamento. Após o abate, as carcaças foram identificadas e resfriadas por 24 horas. Durante a desossa, foram colhidas amostras do contrafilé entre a 10ª e 11ª costelas para análise das características sensoriais e das perdas por cocção; entre a 11ª e 12ª costelas para avaliação da composição centesimal, do valor calórico, do pH e do índice de fragmentação miofibrilar (IFM); e entre a 12ª e 13ª costelas para a avaliação do escore de marmorização e da força de cisalhamento. A composição centesimal, o pH, a força de cisalhamento, o valor calórico, as perdas por cocção e o IFM não diferiram estatisticamente entre os períodos de confinamento. O grau de marmorização diferiu entre as idades de abate, uma vez os animais abatidos aos 75 dias de confinamento apresentaram escore de 1,25; os abatidos aos 100 e 125 dias, escore 2; e aqueles abatidos aos 150 dias de confinamento, escore 2,2. em todos os períodos de confinamento, a carne bubalina foi classificada como macia (média 3,94 kgf) e apresentou com características que não diferiram pelo painel sensorial entre os 75 e 150 dias de confinamento. O abate de bubalinos aos 75 e 150 dias de confinamento não influencia as características sensoriais sabor, aroma e cor da carne bubalina.

Ihmisen papilloomaviruksen serologinen diagnostiikka kahdella eri menetelmällä mitattuna

Ihmisen papilloomavirus (HPV) on pieni kaksisäikeinen DNA-virus, joka infektoi erilaistumiseen kykeneviä ihon ja limakalvon epiteelisoluja. Virus leviää sukupuoliyhdynnän välityksellä, mutta sillä on myös muita leviämistapoja. HPV-infektio voi aiheuttaa syöpää genitaalialueiden lisäksi esimerkiksi pään ja kaulan alueella. Tutkimukseni tavoitteena oli selvittää uuden lateral flow –menetelmään perustuvan Prevo-Check-pikatestin (Abviris, Hünfelden, Saksa) herkkyyttä HPV16-vasta-aineiden osoittamiseksi seerumista. Prevo-Check-testi tehdään sormenpäästä otetusta veripisarasta tai seeruminäytteestä. Tutkimuksessa vertasin Prevo-Check-testituloksia aikaisemmin Luminex-pohjaisella menetelmällä saatuihin tuloksiin. Testit perustuvat HPV16L1-proteiinin vasta-aineiden osoittamiseen, mutta niissä käytetyt antigeenit ovat erilaisia. Luminex-menetelmässä tulokset ilmoitettiin keskifluoresenssi-intensiteettinä (MFI), ja raja positiiviselle näytteelle asetettiin arvolle 400 MFI. Prevo-Check-tulokset analysoitiin testitikun värireaktion perusteella. Tutkimusaineistona käytettiin seeruminäytteitä 34 miehestä, jotka olivat osallistuneet suomalaiseen HPV-infektion tartuntatapoja ja luonnollista taudinkulkua selvittävään tutkimukseen (HUPA). Tutkimukseeni valitut seeruminäytteet olivat Luminex-menetelmän perusteella joko pysyvästi HPV16-seropositiivisia tai juuri HPV-serokonvertoituneita. Näytteitä oli yhteensä 40. Jokainen testattiin kuudella eri näytevolyymilla. Prevo-Check-testi antoi positiivisen tuloksen vain noin 15 %:sta Luminex-menetelmällä positiivisiksi diagnosoiduista näytteistä. Näytteet, joista todettiin korkeat HPV-vasta-ainetiitterit Luminex-menetelmällä (MFI >1500), olivat positiivisia myös Prevo-Check-pikatestillä. Lisäksi Prevo-Check-testi tunnisti positiiviseksi yhden näytteen, jonka MFI oli matala (noin 600). Pieni näytevolyymi ja näytteen pitkä reagointiaika antoivat säännöllisesti negatiivisen Prevo-Check-testituloksen. Prevo-Check-testin herkkyys ei lisääntynyt, vaikka seeruminäytteen volyymi viisinkertaistettiin. Luminex- ja Prevo-Check –menetelmien herkkyyserot johtuvat todennäköisesti antigeeninä käytetyn HPV16L1–proteiinin eri muodoista ja niiden erilaisesta kyvystä sitoutua seerumin HPV-vasta-aineeseen. Lisäksi Prevo-Check-testissä seerumin HPV-vasta-aineiden annetaan sitoutua HPVL1-antigeeniin ennen näytteiden analysointia. Mikäli Prevo-Check-pikatesti osoittaisi seropositiivisuuden ainoastaan kliinisesti relevanteissa infektioissa, eli produktiivisissä ja kroonisissa HPV16-infektioissa, sillä olisi suuri merkitys HPV-tartunnan diagnosoinnissa ja leviämisen ehkäisyssä. Pikatestikäyttö edellyttää kuitenkin menetelmän jatkokehittämistä ja sen herkkyyden lisätutkimusta.

Institutions de microfinance et prêteurs informels de l’agriculture familiale en Côte d’ivoire : de la cohabitation à la fusion

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ENGINEERING HIERARCHICAL MESO-/MICROPOROUS LAMELLAR ZEOLITES WITH VARIABLE TEXTURAL AND CATALYTIC PROPERTIES

Meso-/microporous zeolites combine the charactersitics of well-defined micropores of zeolite with efficient mass transfer consequences of mesopores to increase the efficiency of the catalysts in reactions involving bulky molecules. Different methods such as demetallation and templating have been explored for the synthesis of meso-/microporous zeolites. However, they all have limitations in production of meso-/microporous zeolites with tunable textural and catalytic properties using few synthesis steps. To address this challenge, a simple one-step dual template synthesis approach has been developed in this work to engineer lamellar meso-/microporous zeolites structures with tunable textural and catalytic properties. First, one-step dual template synthesis of meso-/microporous mordenite framework inverted (MFI) zeolite structures was investigated. Tetrapropyl ammonium hydroxide (TPAOH) and diquaternary ammonium surfactant ([C22H45-N+(CH3)2-C6H12-N+(CH3)2-C6H13]Br2, C22-6-6) were used as templates to produce micropores and mesopores, respectively. The variation in concentration ratios of dual templates and hydrothermal synthesis conditions resulted in production of multi-lamellar MFI and the hybrid lamellar-bulk MFI (HLBM) zeolite structures. The relationship between the morphology, porosity, acidity, and catalytic properties of these catalysts was systematically studied. Then, the validity of the proposed synthesis approach for production of other types of zeolites composites was examined by creating a meso-/microporous bulk polymorph A (BEA)-lamellar MFI (BBLM) composite. The resulted composite samples showed higher catalytic stability compared to their single component zeolites. The studies demonstrated the high potential of the one-step dual template synthesis procedure for engineering the textural and catalytic properties of the synthesized zeolites.

Processamento e caracterização da blenda poli (metacrilato de metila) (PMMA) elastomerico e poli (tereftalato de etileno) (PET) pós-consumo

This work studied the immiscible blend of elastomeric poly(methyl methacrylate) (PMMA) with poly(ethylene terephthalate) (PET) bottle grade with and without the use of compatibilizer agent, poly(methyl methacrylate-co-glycidyl methacrylate - co-ethyl acrylate) (MGE). The characterizations of torque rheometry, melt flow index measurement (MFI), measuring the density and the degree of cristallinity by pycnometry, tensile testing, method of work essential fracture (EWF), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were performed in pure polymer and blends PMMA/PET. The rheological results showed evidence of signs of chemical reaction between the epoxy group MGE with the end groups of the PET chains and also to the elastomeric phase of PMMA. The increase in the concentration of PET reduced torque and adding MGE increased the torque of the blend of PMMA/PET. The results of the MFI also show that elastomeric PMMA showed lower flow and thus higher viscosity than PET. In the results of picnometry observed that increasing the percentage of PET resulted in an increase in density and degree crystallinity of the blends PMMA/PET. The tensile test showed that increasing the percentage of PET resulted in an increase in ultimate strength and elastic modulus and decrease in elongation at break. However, in the phase inversion, where the blend showed evidence of a co-continuous morphology and also, with 30% PET dispersed phase and compatibilized with 5% MGE, there were significant results elongation at break compared to elastomeric PMMA. The applicability of the method of essential work of fracture was shown to be possible for most formulations. And it was observed that with increasing elastomeric PMMA in the formulations of the blends there was an improvement in specific amounts of essential work of fracture (We) and a decrease in the values of specific non-essential work of fracture (βWp)

Efeito da adição do poli(etileno acrilato de metila) (ema) e da fibra de linter de algodão nas propriedades do poli(tereftalato de etileno) reciclado (petrec)

The development of new materials to fill the demand of technological advances is a challenge for many researchers around the world. Strategies such as making blends and composites are promising alternatives to produce materials with different properties from those found in conventional polymers. The objective of this study is to evaluate the effect of adding the copolymer poly(ethylene methyl acrylate) (EMA) and cotton linter fibers (LB) on the properties of recycled poly(ethylene terephthalate) (PETrec) by the development of PETrec/EMA blend and PETrec/EMA/LB blend composite. In order to improve the properties of these materials were added as compatibilizers: Ethylene - methyl acrylate - glycidyl methacrylate terpolymer (EMA-GMA) and maleic anhydride grafted polyethylene (PE-g-MA). The samples were produced using a single screw extruder and then injection molded. The obtained materials were characterized by thermogravimetry (TG), melt flow index (MFI) mensurements, torque rheometry, pycnometry to determinate the density, tensile testing and scanning electron microscopy (SEM). The rheological results showed that the addition of the EMA copolymer increased the viscosity of the blend and LB reduces the viscosity of the blend composite. SEM analysis of the binary blend showed poor interfacial adhesion between the PETrec matrix and the EMA dispersed phase, as well as the blend composite of PETrec/EMA/LB also observed low adhesion with the LB fiber. The tensile tests showed that the increase of EMA percentage decreased the tensile strength and the Young s modulus, also lower EMA percentage samples had increased the elongation at break. The blend composite showed an increase in the tensile strength and in the Young`s modulus, and a decrease in the elongation at break. The blend formulations with lower EMA percentages showed better mechanical properties that agree with the particle size analysis which showed that these formulations presented a smaller diameter of the dispersed phase. The blend composite mechanical tests showed that this material is stronger and stiffer than the blend PETrec/EMA, whose properties have been reduced due to the presence of EMA rubbery phase. The use of EMA-GMA was effective in reducing the particle size of the EMA dispersed phase in the PETrec/EMA blend and PE-g-MA showed evidences of reaction with LB and physical mixture with the EMA