The Effect of the Pd Precursors on the Shape of Hollow Ag-Pd Alloy Nanoparticles Using Ag Nanocubes as Seeds

Hollow Ag-Pd nanoparticles have potentially highcatalyticperformance owing to their larger surface area compared to their correspondingsolid nanoparticles. We successfully fabricated hollow Ag-Pdalloy nanodendrites and nanoboxes by using different Pd precursors(H2PdCl4 and Pd(acac)(2)) to achievelarge surface area nanoboxes. Interestingly, the use of a H2PdCl4 precursor led to the formation of hollow nanodendritestructures, whereas the slower reduction of Pd(acac)(2) ledto the formation of hollow nanoboxes. The microstructure and chemicalcomposition of Ag-Pd nanoparticles and properties of theirgrowth solutions were investigated by transmission electron microscopy,energy-dispersive X-ray spectroscopy, and ultraviolet-visiblespectroscopy

Design and Fabrication of Flexible Copper Sensor Decorated with Bismuth Micro/Nanodentrites to Detect Lead and Cadmium in Noninvasive Samples of Sweat

The use of economic methods to design and fabricate flexible copper sensors decorated with bismuth micro/nanodentrites for the detection of lead and cadmium in sweat is demonstrated. The flexible copper sensors were constructed with simple and cost-effective materials; namely, flexible and adhesive conductive copper tape, adhesive label containing the design of a three-electrode electrochemical system, and nail polish or spray as a protective layer. The flexible copper device consisted of a working electrode decorated with bismuth micro/nanodentrites using an electrodeposition technique, a copper pseudo-reference and copper counter electrodes. Under optimal experimental conditions, the flexible sensing platform showed excellent performance toward the detection of lead and cadmium using differential pulse anodic stripping voltammetry (DPAdSV) in a wide linear range from 2.0 μM to 50 μM with acceptable reproducibility and repeatability, and limits of detection and quantification of 5.36 and 17.9 μM for Cd2+ ions and 0.76 μM and 2.5 for Pb2+ ions. Studies of addition and recovery in spiked artificial sweat sample were performed, with a recovery of 104.6%. The flexible copper device provides a great opportunity for application in wearable perspiration-based healthcare systems or portable sensors to detect toxic metals in biological samples

Crescimento e tolerância de Ilex paraguariensis A. St.-Hil. inoculados com fungos ectomicorrízicos em solo contaminado com cobre

O cobre é um dos principais metais pesados contaminantes do solo. As plantas diferenciam-se quanto à sua tolerância e toxicidade, o que lhes permite crescer e produzir até mesmo em solos com altas concentrações. O trabalho objetivou determinar a influência do uso de fungos ectomicorrízicos no crescimento e tolerância de mudas de erva-mate (Ilex paraguariensis) cultivadas em solo contaminado com cobre. O delineamento experimental foi inteiramente casualizado em arranjo fatorial (4x6), sendo quatro inóculos: controle (sem inóculo) e três ectomicorrizas (UFSC-PT116 — Pisolithus microcarpus, UFSC-PT132 — Pisolithus tinctorius e UFSC-SU118 — Suillus cothurnatus) e seis doses de cobre adicionadas ao solo (0, 80, 160, 240, 320 e 400 mg kg-1), com sete repetições. Avaliaram-se: altura da parte aérea, diâmetro do colo, massa seca da parte aérea e sistema radicular, área foliar, área superficial específica de raízes, teores de cobre na parte aérea e radicular, índice de tolerância e associação micorrízica. A inoculação de mudas de erva-mate com ectomicorrizas UFSC-PT116, UFSC-PT132 e UFSC-SU118 ameniza o efeito de fitotoxicidade provocado pelo excesso de cobre no solo. O isolado ectomicorrízico UFSC-PT116 promoveu os maiores crescimento e tolerância de mudas de erva-mate cultivadas em solo contaminado com cobre. Em geral, os isolados promoveram a redução da toxicidade do cobre nas plantas de Ilex paraguariensis, sendo uma alternativa interessante para a recuperação de áreas contaminadas com cobre.Copper (Cu) is one of the main heavy metals contaminating the soil. Plants have different behavior in terms of tolerance and toxicity to metals, being able to grow and produce even in soils contaminated with high concentrations. This study aimed to determine the influence of ectomycorrhizal fungi on the growth and tolerance of yerba mate plants grown in soil contaminated with Cu. The design was completely randomized in a factorial arrangement (4x6), with four possibilities of inoculum: without inoculum (control) and three ectomycorrhizal fungi (UFSC-PT116 — Pisolithus microcarpus, UFSC-PT132 — Pisolithus tinctorius and UFSC-SU118 — Suillus cothurnatus), with six Cu doses amended to the soil (0, 80, 160, 240, 320 and 400 mg kg-1 of Cu) in seven replicates. The height of the aerial part, the diameter of the lap, the dry mass of the aerial part and root system, the leaf area, the specific surface area of the roots, the contents of Cu in the aerial and radicular parts, the tolerance index, and mycorrhizal association were assessed. Inoculation of Ilex paraguariensis seedlings with ectomycorrhiza fungi UFSC-PT116, UFSC-PT132, and UFSC-SU118 mitigates the toxicity effect caused by the excess of Cu in the soil. The UFSC-PT116 isolate promoted the highest growth and tolerance of Ilex paraguariensis seedlings under the treatments. In general, the isolates promoted the reduction of Cu toxicity in Ilex paraguariensis plants, being an important alternative to remediate Cu-contaminated areas

OS MEIOS DE COMUNICAÇÃO PRESENTE NOS PROCESSOS DA TUTORIA DE UM CURSO A DISTÂNCIA

A transformação tecnológica está pautada à aplicação de recursos educacionais na educação a distância (EAD) como veículo para alcançar novos públicos e desenvolver novas metodologias de ensino que possam ser aproveitadas como mecanismo complementar ou integrante do ensino presencial. A partir de uma ampla revisão bibliográfica, abrangendo autores contemporâneos e tradicionais no campo da literatura de EAD, como Belloni (2003), Aretio (2002), Moore e Kearsley (1996), este ensaio teórico busca demonstrar quais os meios de comunicação presente nos processos de tutoria de um curso a distância. Foram utilizados de dois tipos de pesquisa: a bibliográfica e a descritiva. Ao término do estudo, foi traçado a forma e a diversidade desses processos aplicadas à educação a distância

Bacterial nanocellulose in dentistry: Perspectives and challenges

Bacterial cellulose (BC) is a natural polymer that has fascinating attributes, such as biocompatibility, low cost, and ease of processing, being considered a very interesting biomaterial due to its options for moldability and combination. Thus, BC-based compounds (for example, BC/collagen, BC/gelatin, BC/fibroin, BC/chitosan, etc.) have improved properties and/or functionality, allowing for various biomedical applications, such as artificial blood vessels and microvessels, artificial skin, and wounds dressing among others. Despite the wide applicability in biomedicine and tissue engineering, there is a lack of updated scientific reports on applications related to dentistry, since BC has great potential for this. It has been used mainly in the regeneration of periodontal tissue, surgical dressings, intraoral wounds, and also in the regeneration of pulp tissue. This review describes the properties and advantages of some BC studies focused on dental and oral applications, including the design of implants, scaffolds, and wound-dressing materials, as well as carriers for drug delivery in dentistry. Aligned to the current trends and biotechnology evolutions, BC-based nanocomposites offer a great field to be explored and other novel features can be expected in relation to oral and bone tissue repair in the near future.Fil: de Oliveira Barud, Hélida Gomes. BioSmart Nanotechnology, LTDA; BrasilFil: da Silva, Robson Rosa. Chalmers University of Technology; SueciaFil: Costa Borges, Marco Antonio. University of Araraquara; BrasilFil: Castro, Guillermo Raul. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: José Lima Ribeiro, Sidney. São Paulo State University; BrasilFil: da Silva Barud, Hernane. University of Araraquara; Brasi

Synthesis of highly monodisperse Pd nanoparticles using a binary surfactant combination and sodium oleate as a reductant

This study presents the synthesis of monodisperse Pd nanoparticles (NPs) stabilized by sodium oleate (NaOL) and hexadecyltrimethylammonium chloride (CTAC). The synthesis was conducted without traditional reductants and Pd-precursors are reduced by NaOL. It was confirmed that the alkyl double bond in NaOL is not the only explanation for the reduction of Pd-precursors since Pd NPs could be synthesized with CTAC and the saturated fatty acid sodium stearate (NaST). A quantitative evaluation of the reduction kinetics using UV-Vis spectroscopy shows that Pd NPs synthesized with both stabilizer combinations follow pseudo first-order reaction kinetics, where NaOL provides a faster and more effective reduction of Pd-precursors. The colloidal stabilization of the NP surface by CTAC and NaOL is confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) analysis

Macroscopic Anatomy, Histopathology, and Image Diagnosis of Joints and Synovial Cartilages

Joints are physiological connections formed by the association of two or more bones that confer mobility to the skeleton of vertebrates. Composed of several structures, these are often related to pathologies of varied origins, which determine symptomatology of varying degrees of intensity and impairment, responsible for the decrease in life expectancy and the well-being of affected populations. Most of the time, the treatment for these diseases is only symptomatic, aiming at the relief of pain and the return of the patient to daily activities. Thus, there has been an increasing interest in the search for new knowledge about the mechanisms that lead to joint disorders and effective therapeutic resources that may contribute to the fight against pain and to the definitive treatment of joint dysfunctions. To this aim, the knowledge of diagnostic methods, especially imaging methods, is of fundamental importance for the recognition of articular affections, enabling a targeted and effective treatment. Among these auxiliary exams currently used to evaluate the joints, the noninvasive ones are the first choice, where radiography, ultrasonography, magnetic resonance imaging (MRI), computed tomography, and arthroscopy are inserted

An Approach for Reducing the Gap between BPMN Models and Implementation Artifacts

The need for using high-level modeling tools (e.g. BPMN) isincreasing considerably. The proliferation of the service oriented architectures (SOA) is also apparent. In this context, there is a gap between the developed model and its execution. This work introduces the MoSC Translator which translates models produced in BPMN into executable WS-BPEL processes

Towards Generating Richer Code by Binding Security Abstractions to BPMN Task Types

This paper presents an approach for binding security requirements to different BPMN task types to create secure executable business processes.This paper presents an approach for binding security requirements to different BPMN task types to create secure executable business processes