66 research outputs found

    Imaging, quantitation and kinetic modelling of intravitreal nanomaterials

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    In this study, the intravitreal pharmacokinetics of nanomaterials were investigated in vivo in rats and rabbits. Impact of particle size and shape (spherical, longitudinal) on ocular particle distribution and elimination was investigated with fundus camera, optical coherence tomography and ocular fluorophotometry. Differently sized particles showed prolonged ocular retention and remarkable differences in vitreal elimination, but size dependence was consistent, suggesting that other features have influence on their vitreal kinetics. We also demonstrate that liposomes are eliminated from the rabbit vitreous mainly via the anterior route. Simulation of drug concentrations after injection of intravitreal particles shows the importance of synchronized particle retention and drug release rate for efficient drug delivery. In conclusion, we provide kinetic insights in intravitreally administered nanoparticles to improve retinal drug delivery.Peer reviewe

    Crystallization of honey at -20°C

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    Honeys from different regions of the province of Buenos Aires were stored at -20°C, and factors that affect crystallization were analyzed. Crystals were observed by light microscopy. Firmness, adhesivity and viscosity of the samples were measured. Honey was characterized by determining the water activity, turbidity, moisture, fructose, and glucose contents. Results show that the viscous characteristics of the samples depend on the number, size, and disposition of crystals. Various honey samples exhibited Newtonian, pseudoplastic, and thixotropic behaviors. Crystallization was favored at higher moisture contents, suggesting that the parameters that affect honey crystallization at room temperature have a different effect at freezing temperatures. Honey that presented higher values of firmness had a moisture content lower than 17%, and a linear inverse relationship was observed between the adhesivity and firmness of honey samples.Fil: Conforti, Paula Andrea. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Lupano, Cecilia Elena. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Malacalza, Néstor H.. Provincia de Buenos Aires. Ministerio de Asuntos Agrarios; ArgentinaFil: Arias, Verònica Cecilia. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; ArgentinaFil: Castells, Cecilia Beatriz Marta. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Tecnología de Pinturas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones en Tecnología de Pinturas; Argentin

    Crystallization of honey at -20°C

    Get PDF
    Honeys from different regions of the province of Buenos Aires were stored at -20°C, and factors that affect crystallization were analyzed. Crystals were observed by light microscopy. Firmness, adhesivity and viscosity of the samples were measured. Honey was characterized by determining the water activity, turbidity, moisture, fructose, and glucose contents. Results show that the viscous characteristics of the samples depend on the number, size, and disposition of crystals. Various honey samples exhibited Newtonian, pseudoplastic, and thixotropic behaviors. Crystallization was favored at higher moisture contents, suggesting that the parameters that affect honey crystallization at room temperature have a different effect at freezing temperatures. Honey that presented higher values of firmness had a moisture content lower than 17%, and a linear inverse relationship was observed between the adhesivity and firmness of honey samples.Centro de Investigación y Desarrollo en Criotecnología de AlimentosCentro de Investigación y Desarrollo en Tecnología de Pintura

    Classification tree to analyze factors connected with post operative complications of cataract surgery in a teaching hospital

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    Background: Artificial intelligence (AI) is becoming ever more frequently applied in medicine and, consequently, also in ophthalmology to improve both the quality of work for physicians and the quality of care for patients. The aim of this study is to use AI, in particular classification tree, for the evaluation of both ocular and systemic features involved in the onset of complications due to cataract surgery in a teaching hospital. Methods: The charts of 1392 eyes of 1392 patients, with a mean age of 71.3 ± 8.2 years old, were reviewed to collect the ocular and systemic data before, during and after cataract surgery, including post-operative complications. All these data were processed by a classification tree algorithm, producing more than 260 million simulations, aiming to develop a predictive model. Results: Postoperative complications were observed in 168 patients. According to the AI analysis, the pre-operative characteristics involved in the insurgence of complications were: ocular comorbidities, lower visual acuity, higher astigmatism and intra-operative complications. Conclusions: Artificial intelligence application may be an interesting tool in the physician’s hands to develop customized algorithms that can, in advance, define the post-operative complication risk. This may help in improving both the quality and the outcomes of the surgery as well as in preventing patient dissatisfaction

    Advancements in Postoperative Care after Cataract Surgery

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    Cataract surgery is one of the most frequently performed surgical procedures in many countries [...

    Regulatory electron transport pathways of photosynthesis in cyanobacteria and microalgae: Recent advances and biotechnological prospects

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    Cyanobacteria and microalgae perform oxygenic photosynthesis where light energy is harnessed to split water into oxygen and protons. This process releases electrons that are used by the photosynthetic electron transport chain to form reducing equivalents that provide energy for the cell metabolism. Constant changes in environmental conditions, such as light availability, temperature, and access to nutrients, create the need to balance the photochemical reactions and the metabolic demands of the cell. Thus, cyanobacteria and microalgae evolved several auxiliary electron transport (AET) pathways to disperse the potentially harmful over-supply of absorbed energy. AET pathways are comprised of electron sinks, e.g. flavodiiron proteins (FDPs) or other terminal oxidases, and pathways that recycle electrons around photosystem I, like NADPH-dehydrogenase-like complexes (NDH) or the ferredoxin-plastoquinone reductase (FQR). Under controlled conditions the need for these AET pathways is decreased and AET can even be energetically wasteful. Therefore, redirecting photosynthetic reducing equivalents to biotechnologically useful reactions, catalyzed by i.e. innate hydrogenases or heterologous enzymes, offers novel possibilities to apply photosynthesis research

    Influence of Miscanthus rhizome pyrolysis operating conditions on products properties

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    Waste from the Miscanthus production cycle may be a promising source of material for the pyrolysis and biochar production. The biochar can be used to enrich the soil on which the crop grows, thus increasing productivity. A sample of Miscanthus rhizomes was used as a raw material in a series of experiments in order to find the most suitable conditions for the preparation of biochar. Miscanthus biochar was prepared in a laboratory unit using four different temperatures (i.e., 400, 500, 600 and 700 degrees C). All pyrolysis products were subsequently evaluated in terms of their quality and product yields were determined. For a temperature of 600 degrees C and a residence time of 2 h, the appropriate properties of biochar were achieved and the process was still economical. The biochar contained a minimal number of polycyclic aromatic hydrocarbons and a high percentage of carbon. Surface area was measured to be 217 m(2)/g. The aqueous extract of biochar was alkaline.Web of Science1410art. no. 619

    Chemical properties of floral and meadow honey

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    Cilj ovog rada bio je odrediti fizikalno-kemijska svojstva 35 uzorka cvjetnog meda i 11 uzorka livadnog meda te usporediti dobivene vrijednosti u odnosu na zahtjeve Pravilnika o medu. U svim uzorcima meda mjereni su: maseni udio vode, električna provodnost, kiselost, udio reducirajućih šećera, saharoze te hidroksimetilfurfurala. Sve korištene metode propisala je Međunarodna komisija za med. Nakon provedene analize, 7 uzoraka je imalo odstupanja u vrijednosti električne provodnosti, 1 u udjelu saharoze i 2 u udjelu reducirajućih šećera, a ostali su zadovoljili sve zahtjeve Pravilnika.The aim of this paper was to determine the physico-chemical properties of 35 floral honey samples and 11 samples of meadow honey and compare the obtained values with requirements of Croatian Regulative of honey. All samples of honey were measured by weight of water, electrical conductivity, acidity, the proportion of reducing sugars, sucrose and hydroxymethylfurfural. All the methods used were prescribed by the International Honey Commission. After the analysis, 7 samples showed deviations in the value of electrical conductivity, 1 in the sucrose content and 2 in the proportion of reducing sugars, while others met the conditions of Regulative
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