136 research outputs found

    Fluorescence-Labeled Pyrenesulfonamide Response for Characterizing Polymeric Interfaces in Composite Materials

    Get PDF
    E-glass fibers were silanized using a 1% (v/v) aqueous solution of γ-aminopropyltriethoxysilane (APES). Pyrene—sulfonamide conjugates were formed by reaction of 1-pyrenesulfonyl chloride (PSC) in acetonitrile (AcN), with the amine groups immobilized on the glass fiber surface. These pyrene—sulfonamide conjugates were used as fluorescence probes, being a relatively simple analytical method to study the coating microstructure of polyorganosiloxane layer on glass fibers. The first aim of this work was to estimate possible interactions of the polyaminosiloxane coating with surrounding molecules of different solvents (solvent accessibility to the chromophore). For this study, the fluorescence response of pyrene—sulfonamide dye (PSA) was correlated with solvent polarity parameters. It was concluded that all the studied solvents were accessible to the chromophore, and they can gather in two groups, depending on their ability to swell the poliorganosiloxane layer. The second objective was to estimate the rigidity of the coating polymer from the temperature dependence of PSA emission. At about 180 K, a sudden change in the behavior of different photophysical parameters of PSA were observed. This phenomenon was interpreted as a density change in the polyaminosiloxane attached to the glass fibersThis research was supported by integrated actions Portugal–Spain, Reference HP1998-0014. J. Baselga, A. Aznar, and J. González-Benito wish to acknowledge the European Commission for support under the Brite-EuRam program (BE97-4472)

    Desarrollos urbanos y transporte público ferroviario : el caso en la región metropolitana de Madrid: TODs, TADs y TJDs

    Get PDF
    Este artículo se centra en los modelos de ciudad que tratan de favorecer una movilidad más eficiente, como son la planificación y el diseño urbano que favorecen el transporte colectivo en plataforma reservada (metro, ferrocarril, BRT) y, de modo subsidiario, la movilidad peatonal. Se analiza en el caso de la aglomeración madrileña la aplicación del conocido concepto TOD, "Transit Oriented Development" (Desarrollo Urbano Orientado al Transporte Público), diferenciándolo de otros más recientes como los denominados TAD, "Transit Adjcent Development" (Desarrollos junto al transporte público pero que no tienen una planificación coordinada) o los TJD, "Transit Joint Development" (Desarrollo conjunto urbano-infraestructura de transporte).Aquest article se centra en els models de ciutat que tracten d'afavorir una mobilitat més eficient, com són la planificació i el disseny urbà que afavoreixen el transport col·lectiu en plataforma reservada (metro, ferrocarril, BRT) i, de manera subsidiària, la mobilitat de vianants. S'analitza en el cas de l'aglomeració madrilenya l'aplicació del conegut concepte TOD, "Transit Oriented Development" (Desenvolupament Urbà Orientat al Transport Públic), diferenciant-lo d'altres més recents com els denominats TAD, "Transit Adjcent Development" (Desenvolupaments al costat del transport públic però que no tenen una planificació coordinada) o els TJD, "Transit Joint Development" (Desenvolupament conjunt urbà-infraestructura de transport)

    Automated low-cost device to produce sub-micrometric polymer fibers based on blow spun method

    Get PDF
    Attending the latest advances in polymeric fibers, the design of low-cost, and high-quality scientific equipment for obtaining fibers seemed essential. To overcome this challenge, a 3D printable prototype was designed, assembled, and validated to obtain fibers using the SBS method. The particular configuration of the prototype consisted of controlling the process conditions such as working distance and injection flow, as well as other parameters such as RPM and the axial movement of the cylindrical collector. Thus, these parameters were automated using a microcontroller (Arduino) that receives information from an Android device with bluetooth connectivity to control each of the elements of the equipment. Subsequently, the repeatability and reproducibility of the fibers was verified using polymers such as polystyrene (PS), polysulfone (PSF) and polyethylene oxide (PEO); furthermore, PSF fibers were manufactured to analyze the influence of working distance and the axial movement of the collector on their production.Fondos de Investigación de Fco. Javier González Benito, política de reinversión de costes generales, Universidad Carlos III de Madrid [2012/00130/004] and Acción Estratégica en Materiales Compuestos Poliméricos e Interfases, Universidad Carlos III de Madrid [2011/00287/002]. Besides, authors greatly appreciate the Consejo Nacional de Ciencia y Tecnología (CONACyT- México) for financial support associated to the scholarship number 625396

    Influence of root canal instrumentation and obturation techniques on intra-operative pain during endodontic therapy

    Get PDF
    Objective: To analyse the influence of root canal instrumentation and obturation techniques on intra-operative pain experienced by patients during endodontic therapy. Method and Materials: A descriptive cross-sectional study was carried out in Ponferrada and Sevilla, Spain, including 80 patients (46 men and 34 women), with ages ranged from 10 to 74 years, randomly recruited. Patient gender and age, affected tooth, pulpal diagnosis, periapical status, previous NSAID or antibiotic (AB) treatment, and root canal instrumentation and obturation techniques were recorded. After root canal treatment (RCT), patients completed a 10-cm visual analogue scale (VAS) that ranked the level of pain. Results were analysed statistically using the Chi-square and ANOVA tests and logistic regression analysis. Results: The mean pain level during root canal treatment was 2.9 ± 3.0 (median = 2) in a VAS between 0 and 10. Forty percent of patients experienced no pain. Gender, age, arch, previous NSAIDs or AB treatment and anaesthetic type did not influence significantly the pain level (p > 0.05). Pain during root canal treatment was significantly greater in molar teeth (OR = 10.1; 95% C.I. = 1.6 - 63.5; p = 0.013). Root canal instrumentation and obturation techniques did not affect significantly patient?s pain during root canal treatment (p > 0.05). Conclusion: Patients feel more pain when RCT is carried out on molar teeth. The root canal instrumentation and obturation techniques do not affect significantly the patients? pain during RCT

    Effect of the methacrylate-based endodontic sealer Epiphany on rat peritoneal macrophages viability

    Get PDF
    Objective: To evaluate the effect of the endodontic sealer Epiphany on rat peritoneal macrophages viability. Materials and methods: Peritoneal macrophages were obtained from Wistar rats and resuspended in RPMI- 1640 medium. Undiluted (crude extract) and diluted extracts to 10%, 1%, 0.1%, 0.01%, 0.001% and 0.0001% of Epiphany, AH 26 and AH Plus sealers on RPMI-1640 medium were tested for cytotoxicity to rat peritoneal macrophages using the trypan blue dye exclusion assay. Data were analyzed statistically by the Kruskal-Wallis and Mann-Whitney tests at 5% significance level. Results: Crude extract of Epiphany killed 51% of cells, but was less cytotoxic that crude extracts of AH Plus and AH 26, which killed 81% and 86% of cells, respectively. Ten-fold dilutions of Epiphany, AH Plus and AH 26 killed 44%, 56%, 62% of macrophages, respectively. A hundred dilution of Epiphany only killed 7% of macrophages, but the same dilution of AH Plus and AH 26 killed 10% and 31% of macrophages, respectively. Lower dilutions of sealer extracts caused minimal cell death as compared to the control groups (p>0.05). Conclusions: The methacrylate-based endodontic sealer Epiphany showed lower cytotoxicity on macrophages than resin-based sealers AH Plus and AH 26. Dilution of elutes of the three materials by tenfold markedly reduced their effect

    Cyclodextrin-grafted TiO2 nanoparticles: synthesis, complexation capacity, and dispersion in polymeric matrices

    Get PDF
    The modification of the surface of titanium dioxide nanoparticles (TiO2 NPs) by the incorporation of cyclodextrins (CDs), cyclic oligosaccharides with a hydrophobic cavity, can largely improve the functionality of TiO2 by lodging molecules of interest in the CD to act directly on the surface of the nanoparticles or for further release. With this aim, we have synthesized beta CD-modified nanoparticles (beta CDTiO2 NPs) by a two-step reaction that involves the incorporation of a spacer and then the linking of the macrocycle, and characterized them by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The capacity of the functionalized structures to trap model compounds (Rhodamine and 1-naphthol) has been compared to that of bare TiO2 NPs by fluorescence and Ultraviolet-visible (UV-visible) spectroscopy. The presence of the CDs on the surface of the TiO2 avoids the photo-degradation of the guest, which is of interest in order to combine the photocatalytic activity of TiO2, one of its most interesting features for practical purposes, with the delivery of compounds susceptible of being photo-degraded. The beta CDTiO2 NPs have been dispersed in polymeric matrices of frequently used polymers, polyethylene (LDPE) and polyethylene oxide (PEO), by cryogenic high energy ball milling to produce nanocomposites in the form of films. The surface modification of the nanoparticles favors the homogenization of the filler in the matrix, while the nanoparticles, either in bare or functionalized form, do not seem to alter the crystallization properties of the polymer at least up to a 5% (w/w) load of filler

    Strength plus Endurance Training and Individualized Diet Reduce Fat Mass in Overweight Subjects:A Randomized Clinical Trial

    Get PDF
    Studies with overweight people are a priority in order to observe the effect of the timing of intervention on pre-obesity people. The aim was to compare different physical activity programs plus an individualized hypocaloric diet on body composition in overweight subjects. A randomized controlled clinical trial was carried out in overweight adults with no history of relevant illness. Primary outcome was total fat mass (TFM). Participants were allocated into four activity programs with equal intensity and volume of exercise for 22 weeks: strength training (S), endurance training (E), strength + endurance training (SE), and 'adhering to physical activity recommendations' (C). Participants followed a diet with 25% less energy (50%-55% carbohydrates, 30%-35% fat) measured by accelerometer. Variables were assessed at baseline and at the end of the intervention. Body composition was measured by dual-energy X-ray absorptiometry. One hundred nineteen from 205 subjects were randomized in the four exercise groups (S = 30/E = 30/SE = 30/C = 29) and 84 participants (36 men/48 women) ended the intervention (S = 19/E = 25/SE = 22/C = 18). At the end of the experiment, all groups except C increased their total physical activity (S = 1159 ± 1740; E = 1625 ± 1790; SE = 1699 ± 2516; C = 724 ± 1979 MET-min/week). Using an ANOVA-test, improvements were observed in body weight (S = -4.6 ± 4.5; E = -6.6 ± 4.6; SE = -8.5 ± 2.8; C = -6.1 ± 5.6 kg, p = 0.059) and TFM (S = -4.24 ± 2.02; E = -4.74 ± 2.96; SE = -6.74 ± 3.27; C = -3.94 ± 4.18%; p < 0.05). The main conclusion was that there were no adverse events. Strength and endurance training with a balanced, individualized hypocaloric diet was the most effective at reducing weight loss and fat mass in overweight subjects. Trial registration: NCT01116856

    Multidisciplinary Prehabilitation and Postoperative Rehabilitation for Avoiding Complications in Patients Undergoing Resection of Colon Cancer: Rationale, Design, and Methodology of the ONCOFIT Study

    Get PDF
    ONCOFIT is a randomized clinical trial with a two-arm parallel design aimed at determining the influence of a multidisciplinary Prehabilitation and Postoperative Program (PPP) on post-surgery complications in patients undergoing resection of colon cancer. This intervention will include supervised physical exercise, dietary behavior change, and psychological support comparing its influence to the standard care. Primary and secondary endpoints will be assessed at baseline, at preoperative conditions, at the end of the PPP intervention (after 12 weeks) and 1-year post-surgery, and will include: post-surgery complications (primary endpoint); prolonged hospital length of stay; readmissions and emergency department call within 1-year after surgery; functional capacity; patient reported outcome measures targeted; anthropometry and body composition; clinical/tumor parameters; physical activity levels and sedentariness; dietary habits; other unhealthy habits; sleep quality; and fecal microbiota diversity and composition. Considering the feasibility of the present intervention in a real-life scenario, ONCOFIT will contribute to the standardization of a cost-effective strategy for preventing and improving health-related consequences in patients undergoing resection of colon cancer with an important clinical and economic impact, not only in the scientific community, but also in clinical practice.This study was funded by the University of Granada, Plan Propio de Investigación 2016-Excellence actions: Unit of Excellence on Exercise and Health (UCEES). P.C. was supported by the Margarita Salas postdoctoral grant, convened by de University of the Basque Country (UPV/EHU), funded by the Ministry of Universities of Spain and the European Union-Next Generation EU
    corecore