19 research outputs found

    A recent trend of drug-nanoparticles in suspension for the application in drug delivery

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    Persistent development in nanomedicine has enabled successful nanosizing of most drug samples which, in turn, imparts remarkable properties to the drugs such as enhanced solubility and bioavailability for the applications in drug delivery In this context several review articles are available in scientific domain covering inorganic nanoparticles such as Au Ag, SPIONs Qdots, carbon nanotubes and graphene; however, this review covers the development of drug nanoparticles together with their possibilities and limitation from ..

    Systematic mechanical assessment of consolidants for canvas reinforcement under controlled environment

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    In conservation, adhesives are commonly used for the consolidation of canvases, yet their impact upon the canvas longevity has raised some concerns amongst conservators. As such, this study presents a testing protocol developed to assess the performance of commonly-used adhesives (natural animal glue and synthetic Beva® 371) and a newly developed nanocellulose consolidant, nanofibrillated nanocellulose (CNF). This includes their effect on the visual appearance, consolidation, and response of the mechanical properties of the treated canvases to programmed changes in relative humidity (RH). Scanning electron microscopy (SEM) images of animal glue- and Beva® 371-treated canvases revealed the presence of adhesive and consolidant on and in-between cotton fibres. The consolidants form bridges linking and connecting the cotton fibres and holding them together, whereas the CNF treatment, formed a visible continuous and dense surface coating. None of the treatments induced any discernible colour change. Controlled environment mechanical testing was performed in two ways: by applying a linearly increasing static force at fixed RH (Young’s modulus) and by applying a dynamic force together with a programmed RH cycling between 20 and 80% (RH dependent viscoelastic properties). CNF gave a higher value of Young’s modulus than either of the two commonly-used materials. Measurements at different values of RH (20 and 80%) demonstrated for all the treated canvases that at the lower value (RH 20%) Young’s modulus values were higher than at the higher value (RH 80%). Besides, the dynamic mode showed that the rate of response in all cases was rapid and reversible and that the nanofibrillated cellulose treated sample showed the highest variation in storage (or elastic) modulus measured at the end of RH plateaux (20 and 80% RH). Thus CNF appears to be a promising material given its higher mechanical performance. The protocol developed in this study has enabled us to examine and compare candidate materials for the consolidation of canvases systematically, using testing parameters that remained relevant to the field of canvas conservation

    Geração de finos no branqueamento de pasta kraft de eucalipto e seu efeito nas propriedades do papel

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    Este trabalho teve por objetivo avaliar a quantidade de finos gerada por diferentes reagentes de branqueamento e seu efeito nas propriedades físicas e mecânicas da celulose kraft de eucalipto. A polpa foi branqueada por quatro sequências diferentes. Parte das amostras foi classificada em equipamento Bauer-McNett, sendo a parte não classificada (global) refinada para 40 ºSR, em moinho laboratorial PFI. As duas maiores porções de cada amostra proveniente da classificação foram também refinadas com o mesmo número de revoluções que a sua amostra global. Realizaram-se ensaios físicos e mecânicos das amostras refinadas, e suas fibras foram analisadas em equipamento FQA (Fiber Quality Analyser), antes e depois do refino. A maior quantidade de finos foi observada nas polpas refinadas e na sequência-referência. Os resultados de tração foram mais elevados e significativos nas amostras globais; as polpas classificadas não apresentaram diferença entre si, sendo atribuída a maior resistência à tração na presença de finos. A resistência ao rasgo foi afetada pelo comprimento das fibras e não pelo teor de finos. Os maiores valores de ascensão capilar Klemm ocorreram nas amostras classificadas em razão da ausência de finos e do maior comprimento de fibras.The objective of this work was to evaluate the generation of fines by different bleaching reagents and its effect on physical and mechanical properties of eucalyptus kraft pulp. The pulp was bleached by four different sequences. Some of these samples was classified in Bauer-McNett equipment. The unclassified part of the pulp (global) was refined to 40ºSR in a laboratory PFI mill. The two major classified portions of each sample were also refined at the same revolutions as its global sample. Physical and mechanical tests were performed for both classified and unclassified samples, and their fibers were analyzed in FQA (Fiber Quality Analyzer), before and after refining.The greater amount of fines was observed for the refined pulp and the reference sequence. The tensile results were more significant for the global sample, classified pulps showed no difference between them being given the highest tensile strength to the presence of fines. The tear resistance was affected by the length of the fibers and not by the content of fines. The highest values of capillarity for the Klemm samples were classified due to the absence of fines and fibers of greater length.Universidade Estadual Paulista Faculdade de Engenharia de Guaratinguetá Progrma de Pós-Graduação em Engenharia MecânciaUniversidade Estadual Paulista Júlio de Mesquita FilhoUniversidade Estadual Paulista Faculdade de Engenharia de Guaratinguetá Progrma de Pós-Graduação em Engenharia MecânciaUniversidade Estadual Paulista Júlio de Mesquita Filh

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    Evaluation of Failure in Single-Piece Implant Systems: A One-Year Follow-Up Study

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    Objective: This study's goal was to assess the failure rate and peri-implant complications of single-piece implant systems over the course of a one-year follow-up. Materials and Methods: Patient records were examined retrospectively. 150 single-piece dental implants were analyzed. Clinical results, implant features, and demographic information were gathered. Implant failure, which is characterized as the total loss of osseointegration, served as the key outcome indicator. Patient satisfaction and peri-implant problems were secondary outcomes. Data analysis employed descriptive statistics. Results: During the one-year follow-up period, the failure rate for single-piece implant systems was 6.7%. The two main factors leading to implant failure were found to be poor osseointegration (60%) and biomechanical overload (40%). 20% of the cases had peri-implant problems, such as peri-implantitis. 85% of the panelists felt that single-piece implants had satisfied their patients. Conclusion: A 6.7% failure rate in single-piece implant systems was seen in this one-year follow-up investigation. The major causes of implant failure were found to be poor osseointegration and biomechanical loading. In 20% of the cases, peri-implant problems such as peri-implantitis, were noted. There was great patient satisfaction. These results highlight the significance of regulating occlusal forces, optimizing osseointegration, and applying preventive measures to ensure the long-term viability of single-piece implant systems
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