RESUMO

The overactive bladder is a condition characterized by a sudden urge to urinate, even with small volumes of urine present in the bladder. The current treatments available for this pathology consist on conservative approaches and the continuous administration of drugs, which when made by conventional methods has limitations related to the first pass metabolism, bioavailability, severe side effects, and low patient adherence to treatments, ultimately leading to low effectiveness. Within this context, the present work proposes the design, manufacture, and characterization of an intravesical implant for the treatment of overactive bladder pathology, using EVA copolymer as a matrix and oxybutynin as a drug. The fabrication of devices through two manufacturing techniques (extrusion and additive manufacturing by fused filament fabrication, FFF) and the evaluation of the implants through characterization tests was proposed. The usability and functionality were evaluated through simulated insertion of the device/prototype in a bladder model through catheter insertion tests. The safety and effectiveness of the devices was investigated from mechanical testing as well as drug release assays. Drug release assays presented a burst release in the first 24 h, followed by a release of 1.8 and 2.8 mg/d, totalizing 32 d. Mechanical tests demonstrated an increase in the stiffness of the specimens due to the addition of the drug, showing a change in maximum stress and strain at break. The released dose was higher than that usually presented when considering the oral administration route, showing the optimization of the development of this implant has the potential to improve the quality of life of patients with overactive bladder.

Assuntos

RESUMO

The threat of microplastics (MP) pollution in aquatic ecosystems can be even more severe for they are able to interact with organic pollutants that can migrate to adjacent environments. The presence of heteroatoms in organic pollutants can directly influence adsorption onto MP. This research evaluated the adsorption of fluorene (FLN) and its heteroatom analogs dibenzothiophene (DBT), dibenzofuran (DBF) and carbazole (CBZ) onto high-density polyethylene (HDPE) MP from residual (HDPEres) and commercial (HDPEcom) sources. The Langmuir isotherm showed a better fit, while DBT showed higher maximum adsorption capacity (19.2 and 15.8 µmol g-1) followed by FLN (13.4 and 11.7 µmol g-1), and DBF (13.5 and 10.3 µmol g-1) to the HDPEcom and HDPEres, respectively, which indicates a direct correlation with the hydrophobicity of the molecules determined by Log Kow. In contrast, CBZ showed no significant interaction with MP, due to their polar characteristic, thus, no kinetic and thermodynamic parameters could be determined. The adsorption process of all PAH was determined to be exothermic and spontaneous, with low temperatures favoring the process. The pseudo-second-order kinetic models have fitted to the adsorption onto both HDPE; intraparticle diffusion was also observed. Computational studies, physical characterization techniques and batch adsorption experiments demonstrated that the mechanism is governed by hydrophobic interactions, with van der Waals forces as a secondary effect in the adsorption of FLN, DBT and DBF onto HDPEres and HDPEcom. Thus, allowing a deeper understanding of the interactions between HDPE MP and FLN as well with its derivatives.

Assuntos

RESUMO

Natural lignocellulosic fibers (NLFs) have been used as a reinforcement for polymer matrix composites in the past couple of decades. Their biodegradability, renewability, and abundance make them appealing for sustainable materials. However, synthetic fibers surpass NLFs in mechanical and thermal properties. Combining these fibers as a hybrid reinforcement in polymeric materials shows promise for multifunctional materials and structures. Functionalizing these composites with graphene-based materials could lead to superior properties. This research optimized the tensile and impact resistance of a jute/aramid/HDPE hybrid nanocomposite by the addition of graphene nanoplatelets (GNP). The hybrid structure with 10 jute/10 aramid layers and 0.10 wt.% GNP exhibited a 2433% increase in mechanical toughness, a 591% increase in tensile strength, and a 462% reduction in ductility compared to neat jute/HDPE composites. A SEM analysis revealed the influence of GNP nano-functionalization on the failure mechanisms of these hybrid nanocomposites.

RESUMO

In this study, the effect of the recycling process and copper particle incorporation on virgin and recycled pellet HDPE were investigated by thermo-chemical analysis, mechanical characterization, and antibacterial analysis. Copper particles were added to pellet HDPE, virgin and recycled, using a tabletop single screw extruder. Some copper particles, called copper nano-particles (Cu-NPs), had a spherical morphology and an average particle size near 20 nm. The others had a cubic morphology and an average particle size close to 300 nm, labeled copper nano-cubes (Cu-NCs). The thermo-chemical analysis revealed that the degree of crystallization was not influenced by the recycling process: 55.38 % for virgin HDPE and 56.01% for recycled HDPE. The degree of crystallization decreased with the addition of the copper particles. Possibly due to a modification in the structure, packaging organization, and crystalline ordering, the recycled HDPE reached a degree of crystallization close to 44.78% with 0.5 wt.% copper nano-particles and close to 36.57% for the recycled HDPE modified with 0.7 wt.% Cu-NCs. Tensile tests revealed a slight reduction in the tensile strength related to the recycling process, being close to 26 MPa for the virgin HDPE and 15.99 MPa for the recycled HDPE, which was improved by adding copper particles, which were near 25.39 MPa for 0.7 wt.% copper nano-cubes. Antibacterial analysis showed a reduction in the viability of E. coli in virgin HDPE samples, which was close to 8% for HDPE containing copper nano-particles and lower than 2% for HDPE having copper nano-cubes. In contrast, the recycled HDPE revealed viability close to 95% for HDPE with copper nano-particles and nearly 50% for HDPE with copper nano-cubes. The viability of S. aureus for HDPE was lower than containing copper nano-particles and copper nano-cubes, which increased dramatically close to 80% for recycled HDPE with copper nano-particles 80% and 75% with copper nano-cubes.

RESUMO

Introducción: las fracturas de pared de órbita pueden producir secuelas funcionales y estéticas. La indicación de reconstrucción quirúrgica, es indispensable para la recuperación de la motilidad y estética ocular. Los materiales reconstructivos más utilizados son los aloplásticos, como el titanio y el polietileno poroso de alta densidad (PPAD), el cual ha resultado exitoso en reconstrucción maxilofacial. El propósito de este estudio retrospectivo, es exponer los resultados tras el uso del PPAD en reconstrucciones orbitarias y sus posibles complicaciones. Materiales y métodos: se realizó una revisión retrospectiva de 22 pacientes donde se utilizó PPAD como material de reconstrucción en fracturas orbitarias. Se consideró para la indicación quirúrgica que el paciente presentara alguno de los siguientes signos: diplopía o síntomas vasovagales por atrapamiento muscular, restricciones en la motilidad ocular, enoftalmo mayor a 4mm. El material utilizado fue PPAD (Medpor Stryker®) puro en 17 casos y PPAD reforzado con una malla de titanio en el interior de su estructura (Medpor Titan Stryker®), en los 5 restantes. Resultados: se registraron 3 casos con complicaciones; ectropión, diplopía y ectropión con diplopía, los cuales todos fueron reversibles. No se registraron casos de infección ni complicaciones oftalmológicas postoperatoria. Discusión: los injertos autólogos fueron los primeros utilizados con resultados de compatibilidad y resistencia óptimos. El uso de PPAD como material de reconstrucción ha sido bien documentado con buenos resultados en términos de una baja incidencia de infección y óptima motilidad ocular a largo plazo.

Introduction: Orbital wall fractures can cause functional and aesthetic sequelae. When there is an indication for surgical reconstruction, this is essential for the recovery of ocular motility and aesthetics. The most commonly used reconstructive materials are alloplastics, such as titanium and porous high-density polyethylene (PPAD), which have been successful in maxillofacial reconstruction. The purpose of this retrospective study is to present the results and their possible complications in orbital reconstruction with PPAD. Materials and methods: a retrospective review of 22 patients in whom PPAD was used as reconstruction material for orbital fractures was performed. It was considered for the surgical indication that the patient presented any of the following signs: diplopia or vasovagal symptoms due to muscle entrapment, ocular motility restrictions, enophthalmos greater than 4mm. The material used was pure PPAD (Medpor Stryker®) in 17 cases, and PPAD reinforced with a titanium mesh inside its structure (Medpor Titan Stryker®), in the remaining 5. Results: 3 patients with complications were registered; ectropion, diplopia, and ectropion with diplopia, all of which were reversible. There were no cases of postoperative infection or ophthalmological complications. Discussion: Autologous grafts were the first used with optimal compatibility and resistance results. The use of PPAD as a reconstruction material has been well documented with good results in terms of a low incidence of infection and optimal long-term ocular motility

RESUMO

High-density polyethylene (HDPE) geomembranes are polymeric geosynthetic materials usually applied as a liner in environmental facilities due to their good mechanical properties, good welding conditions, and excellent chemical resistance. A geomembrane's field performance is affected by different conditions and exposures, including ultraviolet radiation, thermal and oxidative exposure, and chemical contact. This article presents an experimental study with a 1.0 mm-thick HDPE virgin geomembrane exposed by the Xenon arc weatherometer for 2160 h and the ultraviolet fluorescent weatherometer for 8760 h to understand the geomembrane's behavior under ultraviolet exposure. The evaluation was performed using the melt flow index (MFI) test, oxidative-induction time (OIT) tests, tensile test, differential scanning calorimetry (DSC) analysis, and Fourier transform infrared spectroscopy (FTIR) analysis. The sample exposed in the Xenon arc equipment showed a tendency to increase the MFI values during the exposure time. This upward trend may indicate morphological changes in the polymer. The tensile behavior analysis showed a tendency of the sample to lose ductility, without showing brittle behavior. The samples' OIT test results under both device exposures showed faster antioxidant depletion for the standard OIT test than the high-pressure OIT test. The DSC and FTIR analyses did not demonstrate the polymer's changes.

RESUMO

Waste cooking oil (WCO) is a valuable feedstock for the synthesis of biodiesel but the product exhibits poor oxidative stability. Techniques available for assessing this parameter are generally expensive and time-consuming, hence the purpose of this study was to develop and validate a rapid and reliable predictive system based on signals from the sensors of a commercial hand-held e-nose instrument. Biodiesels were synthesized from soybean oil and six samples of WCO, and their physicochemical characteristics and oxidative stabilities determined before and after storage in different types of containers for 30 or 60 days at room temperature or 43 °C. Linear regression models were constructed based on principal component analysis of the signals generated by all 32 e-nose sensors and stochastic modeling of signal profiles from individual sensors. The regression model with principal components as predictors was unable to explain the oxidative stability of biodiesels, while the regression model with stochastic parameters (combining signals from 11 sensors) as predictors showed an excellent goodness of fit (R2 = 0.91) with a 45-sample training set and a good quality of prediction (R2 = 0.84) with a 18-sample validation set. The proposed e-nose system was shown to be accurate and efficient and could be used to advantage by producers/distributors of biodiesel in the assessment fuel quality.

RESUMO

This data article is related to the research article "Comparative life cycle assessment of coffee jar lids made from biocomposites containing poly (lactic acid) and banana fiber". The article reports the model parameters used to construct each stage and unit process inventory of the life cycle of coffee jar lids, and the subsequent inventories of the investigated system. It also contains details of calculations and descriptions of inventory uncertainties. Primary data were obtained from lab-scale and pilot-scale tests during product preparation. Secondary data collection was based on detailed review of related international and regional literature, databases and recognized web sites. The data presented here can be used by future life cycle assessment studies on natural fiber composites in packaging applications.

RESUMO

Composites containing bio-based materials, like banana fiber and poly(lactic acid) (PLA), are potential food-packaging materials. We carried out an environmental life cycle assessment (LCA) of coffee jar lids made from high density polyethylene (HDPE), PLA, and banana fiber to assess their environmental performance. We considered differences in the type of blend (content of PLA and banana fiber in the composite), origin of the banana fiber feedstock (considered as either biowaste or as a co-product from banana production) and banana fiber pretreatment conditions (either no pretreatment or pretreatment using chemicals). Irrespective of the scenario, a lid made from 40% banana fiber and equal amounts of HDPE and PLA performed significantly better in all 18 impact categories when compared to a lid made from 100% PLA. By contrast, the same lid performed significantly better in 3 impact categories only (climate change, photochemical oxidant formation and fossil depletion) when compared to a lid made from 100% HDPE. Thus, environmental performance of the biocomposite strongly depends on which polymer base is replaced by the banana fiber in the composite. Replacing PLA with banana fiber is generally expected to bring environmental benefits.

Assuntos

RESUMO

High density polyethylene (HDPE) is a synthetic biomaterial used as a three-dimensional scaffold for bone defect reconstruction. Reports differ with regard to its biological response, particularly its osteoconductive capacity. The aim of the present work was to histologically and histomorphometrically evaluate tissue response to porous HDPE. An in vivo study was conducted in rat tibia to evaluate osteogenic capacity, angiogenesis, inflammatory response, and the presence of multinucleated giant cells 14 and 60 days post-biomaterial implantation. Histological examination 14 days post-implantation showed fibrovascular tissue inside pores and on the surface of porous HDPE, acute inflammatory response, scant multinucleated giant cells (MNGCs), and lamellar bone in contact with the biomaterial. An increase in the proportion of lamellar bone tissue, no inflammatory response, and a decrease in the number of MNGCs were observed at 60 days. The histomorphometric study showed a significant time-dependent increase both in the area of bone tissue formed in contact with the porous HDPE (14d: 24.450 ± 11.623 µm2 vs. 60d: 77.104 ± 26.217 µm2, p < 0.05) and in the percentage of bone tissue in contact with the porous HDPE (osseointegration). A significant decrease in the number of MNGCs was also observed at 60 days post-implantation. Porous HDPE showed adequate osteoconductive properties, and only caused an initial inflammatory response. Although this biomaterial has traditionally been used juxtaosseoulsy, its adequate osteoconductive properties broaden the scope of its application to include intraosseous placement.

Assuntos

RESUMO

Introducción: el D-004 es un ingrediente farmacéutico activo obtenido de los frutos de la palma real cubana (Roystonea regia), compuesto fundamentalmente por una mezcla de ácidos grasos libres entre 8 y 18 átomos de carbono, con potencialidades en el tratamiento de la hiperplasia prostática benigna. Objetivo: determinar la vida útil del D‒004 en frascos de polietileno de alta densidad en las zonas climáticas IV y II. Métodos: muestras de tres lotes pilotos de D-004, envasadas en frascos blancos de polietileno de alta densidad y protegidos por cajas de cartón, se colocaron en las condiciones de las zonas climáticas IV (30 ºC/70 % HR) y II (25 ºC/60 % HR). Se determinaron las características organolépticas y los contenidos de material insaponificable, ácidos grasos y microbiológicos desde el tiempo inicial hasta los 36 meses, y se determinaron gráficamente los tiempos de vida útil en ambas zonas. Resultados: en las dos zonas climáticas el D‒004 cumplió con los parámetros de estabilidad evaluados durante los primeros 33 meses, pero a los 36 meses el contenido de ácidos fue inferior al límite establecido en varias de las muestras. Los análisis de regresión permitieron determinar tiempos de vida útil del D‒004 en las zonas IV y II. Conclusiones: se demostró que el ingrediente activo D‒004 que se obtuvo a escala piloto, se envasa en frascos de polietileno de alta densidad y protegido por un envase secundario (caja de cartón), presenta una vida útil de 30 y 32 meses en las zonas climáticas IV y II, respectivamente(AU)

Introduction: D­004 is a pharmaceutical active ingredient obtained from the Cuban royal palm fruits (Roystonea regia), mainly composed by a mixture of free fatty acids between 8 and 18 carbon atoms, potentially useful to treat benign prostatic hyperplasia. Objective: to determine the shelf life of D­004 in high-density polyethylene flasks in climatic zones IV and II. Methods: samples of three pilot batches of D­004, packed in white high-density polyethylene flasks and protected by cardboard boxes, were placed under conditions of the climatic zones IV (30 ºC/70 % RH) and II (25 ºC / 60 % RH). Organoleptic characteristics and unsaponifiable matter, fatty acids and microbiological contents were determined from the initial time till 36 months, and shelf lives were graphically determined in both zones. Results: in the two climatic zones, the D­004 fulfilled the tested stability parameters during the first 33 months, but at the month 36th, the acid content in several samples was lower than the set limit. The regression analyses allowed determining the shelf lives of D­004 in climatic zones IV and II. Conclusions: it was demonstrated that the active ingredient D­004, obtained at pilot scale, packed in high density polyethylene flasks and protected by a secondary container (cardboard box), exhibits a shelf life of 30 and 32 months in the climatic zones IV and II, respectively(AU)

Assuntos

RESUMO

Factorial Design Methodology (FDM) was developed to enhance diesel fuel fraction (C9-C23) from waste high-density polyethylene (HDPE) and Heavy Gas Oil (HGO) through co-pyrolysis. FDM was used for optimization of the following reaction parameters: temperature, catalyst and HDPE amounts. The HGO amount was constant (2.00 g) in all experiments. The model optimum conditions were determined to be temperature of 550 °C, HDPE = 0.20 g and no FCC catalyst. Under such conditions, 94% of pyrolytic oil was recovered, of which diesel fuel fraction was 93% (87% diesel fuel fraction yield), no residue was produced and 6% of noncondensable gaseous/volatile fraction was obtained. Seeking to reduce the cost due to high process temperatures, the impact of using higher catalyst content (25%) with a lower temperature (500 °C) was investigated. Under these conditions, 88% of pyrolytic oil was recovered (diesel fuel fraction yield was also 87%) as well as 12% of the noncondensable gaseous/volatile fraction. No waste was produced in these conditions, being an environmentally friendly approach for recycling the waste plastic. This paper demonstrated the usefulness of using FDM to predict and to optimize diesel fuel fraction yield with a great reduction in the number of experiments.

Assuntos

RESUMO

Solid waste, including municipal waste and its management, is a major challenge for most cities and among the key contributors to climate change. Greenhouse gas emissions can be reduced through recovery and recycling of resources from the municipal solid waste stream. In São Paulo, Brazil, recycling cooperatives play a crucial role in providing recycling services including collection, separation, cleaning, stocking, and sale of recyclable resources. The present research attempts to measure the greenhouse gas emission reductions achieved by the recycling cooperative Cooperpires, as well as highlight its socioeconomic benefits. Methods include participant observation, structured interviews, questionnaire application, and greenhouse gas accounting of recycling using a Clean Development Mechanism methodology. The results show that recycling cooperatives can achieve important energy savings and reductions in greenhouse gas emissions, and suggest there is an opportunity for Cooperpires and other similar recycling groups to participate in the carbon credit market. Based on these findings, the authors created a simple greenhouse gas accounting calculator for recyclers to estimate their emissions reductions.

Assuntos

RESUMO

INTRODUCCIÓN: D-004 es un nuevo ingrediente activo en fase de investigación y desarrollo, obtenido de los frutos de Roystonea regia (Kunth) O.F. Cook. OBJETIVO: precisar la estabilidad de D-004 en condiciones aceleradas en frascos de vidrio ámbar, de tereftalato de polietileno y de polietileno de alta densidad. MÉTODOS: muestras de 3 lotes se almacenaron a (40 ± 2) ºC y (75 ± 5) porciento de humedad relativa durante 12 meses. Se determinaron las características organolépticas, la densidad relativa, el índice de refracción (USP 27) y el contenido de ácidos grasos mediante cromatografía de gases. RESULTADOS: los parámetros medidos se mantuvieron dentro de las especificaciones de calidad establecidas, con excepción del contenido de ácidos grasos, que en los frascos de tereftalato y polietileno disminuyó significativamente a los 3, 6 y 4,5 meses, respectivamente. CONCLUSIONES: el vidrio ámbar protege al D-004 de la degradación más que los envases plásticos estudiados.

INTRODUCTION: D-004 is a new active ingredient under research and development stage, which is obtained from Roystonea regia (Kunth) O. F. Cook fruits. OBJECTIVE: to precise over the D-004 stability under accelerated conditions in amber glass, polyethylene terephtalate and high density polyethylene containers. METHODS: samples from three batches were stored at (40 ± 2) ºC and (75 ± 5) percent relative humidity for 12 months. Organoleptic characteristics, relative density, refractive index (USP 27) and fatty acids content by gas chromatography, were determined. RESULTS: measured parameters were within the set quality specifications , except for fatty acids content that significantly decreased in polyethylene terephtalate and high density polyethylene containers after 3, 4 and a half and 6 months, respectively. CONCLUSIONS: the amber glass protects more D-004 from degradation than the analyzed plastic containers.

Assuntos