Multihierarchical electrodes based on titanate nanotubes and zinc oxide nanorods for photoelectrochemical water splitting

Studies involving water splitting to form hydrogen and oxygen have attracted attention because H2 is considered the fuel of the future. Photoelectrocatalysts have been widely used for this application, and several metal oxides can be applied as catalysts. Among them, we highlight zinc oxide nanorods (ZnONRs) and titanate nanotubes (TiNTs); however, their individual nanostructures exhibit disadvantages. For example, ZnONR shows rapid recombination of the photogenerated charges, and TiNT gives rise to randomly orientated films; these disadvantages limit their application as photoanodes. In this study, for the first time, we present a new class of multihierarchical electrodes based on TiNT-decorated ZnONR films that exhibited superior results to the individual species. The TiNTs are homogenously dispersed over the surface of the rods without forming agglomerates, giving rise to a heterojunction that exhibits lower recombination rates. It was found that the results are better when the contents of TiNT in the electrode are higher; thus, glycine was successfully used as a bridge to link both of the structures, increasing the amount of TiNT decorating the rods. As a result, the photocurrent generated with these multihierarchical electrodes is higher than that obtained for pure ZnONR electrodes (0.9 mA and 0.45 mA, respectively), and the electrode potentials for O2 evolution is lower than that observed for pure TiNT electrodes (0 V and 0.8 V vs. ERHE, respectively). The IPCE values are also higher for the multihierarchical electrodes

Inferring mixed-culture growth from total biomass data in a wavelet approach

It is shown that the presence of mixed-culture growth in batch fermentation processes can be very accurately inferred from total biomass data by means of the wavelet analysis for singularity detection. This is accomplished by considering simple phenomenological models for the mixed growth and the more complicated case of mixed growth on a mixture of substrates. The main quantity provided by the wavelet analysis is the Holder exponent of the singularity that we determine for our illustrative examples. The numerical results point to the possibility that Holder exponents can be used to characterize the nature of the mixed-culture growth in batch fermentation processes with potential industrial applications. Moreover, the analysis of the same data affected by the common additive Gaussian noise still lead to the wavelet detection of the singularities although the Holder exponent is no longer a useful parameterComment: 17 pages and 10 (png) figure

Influence Of A Cobalt-chromium Metal Framework On Surface Roughness And Knoop Hardness Of Visible Light-polymerized Acrylic Resins

Although visible light-polymerized acrylic resins have been used in removable partial dentures, it is not clear whether the presence of a metal framework could interfere with their polymerization, by possibly reflecting the light and affecting important properties, such as roughness and hardness, which would consequently increase biofilm accumulation. The aim of this study was to compare the roughness and Knoop hardness of a visible light-polymerized acrylic resin and to compare these values to those of water-bath- and microwave-polymerized resins, in the presence of a metal framework. Thirty-six specimens measuring 30.0 x 4.0 ± 0.5 mm of a microwave- (Onda Cryl), a visible light- (Triad) and a water-bath-polymerized (Clássico) (control) acrylic resins containing a cobalt-chromium metal bar were prepared. After processing, specimens were ground with 360 to 1000-grit abrasive papers in a polishing machine, followed by polishing with cloths and 1-μm diamond particle suspension. Roughness was evaluated using a profilometer (Surfcorder SE 1700) and Knoop hardness (Kg/mm 2) was assayed using a microhardness tester (Shimadzu HMV 2000) at distances of 50, 100, 200, 400 and 800 μm from the metal bar. Roughness and Knoop hardness means were submitted to two-way ANOVA and compared by Tukey and Kruskal Wallis tests at a 5% significance level Statistically significant differences were found (p<0.05) for roughness and Knoop hardness, with light-polymerized resin presenting the highest values (Ra = 0.11 μm and hardness between 20.2 and 21.4 Kg/mm 2). Knoop values at different distances from the metal bar did not differ statistically (p>0.05). Within the limitations of this in vitro study, it was concluded that the presence of metal did not influence roughness and hardness values of any of the tested acrylic resins.143208212Anusavice, K.J., (2003) Philip's Science of Dental Materials. 11 th Ed., p. 96. , 11 St. Louis: Elsevier ScienceBollen, C.M.L., Lambrechts, P., Quirynen, M., Comparison of surface roughness of oral hard materials to the threshold surface roughness for bacterial plaque retention: A review of the literature (1997) Dent Mater, 13 (4), pp. 258-269Borchers, L., Tavassol, F., Tschernitschek, H., Surface quality achieved by polishing and by varnishing of temporary crown and fixed partial denture resins (1999) J Prosthet Dent, 82 (5), pp. 550-556Braun, K.O., Del Bel Cury, A.A., Cury, J.A., Use of microwave energy for processing acrylic resin near metal (1998) Braz Oral Res, 12 (2), pp. 173-180Curtis, D.A., Eggleston, T.L., Marshall, S.J., Watanabe, L.G., Shear bond strength of visible-light-cured resin relative to heat-cured resin (1989) Dental Mater, 5 (7), pp. 314-318De Clerck, J.P., Microwave polymerization of acrylic resins used in dental prosthesis (1987) J Prosthet Dent, 57 (5), pp. 650-658Khan, Z., Von Fraunhofer, J.A., Razavi, R., The staining characteristics, transverse strength, and microhardness of a visible light-cured denture base material (1987) J Prosthet Dent, 57 (3), pp. 384-386Levin, B., Sanders, J.L., Reitz, P.V., The use of microwave energy for processing acrylic resins (1989) J Prosthet Dent, 61 (3), pp. 381-383Ogle, R.E., Sorensen, S.E., Lewis, E.A., A new visible light-cured resin system applied to removable prosthodontics (1986) J Prosthet Dent, 56 (4), pp. 497-506Quirynen, M., Cml, B., Willems, G., Van Steenberghe, D., Comparison of surface characteristics of six commercially pure titanium abutments (1994) JOMI, 9 (1), pp. 71-76Reitz, P.V., Sanders, J.L., Levin, B., The curing of denture acrylic resins by microwave energy. Physical properties (1985) Quintessence Int, 6 (8), pp. 547-551Rodrigues Garcia, R.C.M., Souza Jr., J.A., Rached, R.N., Del Bel Cury, A.A., Effect of denture cleansers on the surface roughness and hardness of a microwave-cured acrylic resin and dental alloys (2004) J Prosthodont, 13 (3), pp. 1-6Rueggeberg, F.A., Goughman, W.F., Curtis Jr., J.W., Effect of light intensity and exposure duration on cure of resin composite (1994) Oper Dent, 19 (1), pp. 26-32Truong, V.T., Thomasz, F.G., Comparison of denture acrylic resins cured by boiling water and microwave energy (1988) Aust Dent J, 33 (3), pp. 201-204Ulusoy, M., Ulusoy, N., Aydin, A.K., An evaluation of polishing technique on surface roughness of acrylic rsins (1986) J Prosthetic Dent, 56 (1), pp. 107-11

Modulation Of The Catalytic Activity Of Porphyrins By Lipid- And Surfactant-containing Nanostructures

The structural factors modulating porphyrin activity encompass pyrrole and equatorial ligands, as well as the central metal and the number and structure of their axial ligands. Of equal importance is the microenvironment provided by apoproteins, solvents and membranes. Porphyrins are often used to construct supramolecular structures with different applications. The modulation of activity of the porphyrins has been frequently achieved by mimicking nature, i.e., by the provision of different microenvironments for these molecules. The association of porphyrins to surfactant- and lipid-containing nanostructures has changed the activity of these compounds to mimic different enzymes such as SOD, cytochrome P450, peroxidases and others. In determined conditions, the reactive forms of the porphyrins are high-valence states of oxo-metal-π cations and oxo-metal produced by the reaction with peroxides and peracids. 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Neuroimmunomodulatory and neuroprotective effects of the flavonoid apigenin in in vitro models of neuroinflammation associated with Alzheimer's disease

Neurodegenerative disorders (ND) are characterized by the progressive and irreversible loss of neurons. Alzheimer’s Disease (AD) is the most incident age-related ND, in which the presence of a chronic inflammatory compound seems to be related to its pathogenesis. Different stimuli in the central nervous system (CNS) can induce activation, proliferation, and changes in phenotype and glial function, which can be modulated by anti-inflammatory agents. Apigenin (4,5,7–trihydroxyflavone) is a flavonoid found in abundance in many fruits and vegetables, that has shown important effects upon controlling the inflammatory response. This study evaluated the neuroprotective and neuroimmunomodulatory potential of apigenin using in vitro models of neuroinflammation associated with AD. Co-cultures of neurons and glial cells were obtained from the cortex of newborn and embryonic Wistar rats. After 26 days in vitro, cultures were exposed to lipopolysaccharide (LPS; 1 μg/ml), or IL-1β (10 ng/ml) for 24 h, or to Aβ oligomers (500 nM) for 4 h, and then treated with apigenin (1 μM) for further 24 h. It was observed that the treatment with apigenin preserved neurons and astrocytes integrity, determined by Rosenfeld’s staining and immunocytochemistry for β-tubulin III and GFAP, respectively. Moreover, it was observed by Fluoro-Jade-B and caspase-3 immunostaining that apigenin was not neurotoxic and has a neuroprotective effect against inflammatory damage. Additionally, apigenin reduced microglial activation, characterized by inhibition of proliferation (BrdU+ cells) and modulation of microglia morphology (Iba-1 + cells), and decreased the expression of the M1 inflammatory marker CD68. Moreover, as determined by RT-qPCR, inflammatory stimuli induced by IL-1β increased the mRNA expression of IL-6, IL-1β, and CCL5, and decreased the mRNA expression of IL-10. Contrary, after treatment with apigenin in inflammatory stimuli (IL-1β or LPS) there was a modulation of the mRNA expression of inflammatory cytokines, and reduced expression of OX42, IL-6 and gp130. Moreover, apigenin alone and after an inflammatory stimulus with IL-1β also induced the increase in the expression of brain-derived neurotrophic factor (BDNF), an effect that may be associated with anti-inflammatory and neuroprotective effects. Together these data demonstrate that apigenin presents neuroprotective and anti-inflammatory effects in vitro and might represent an important neuroimmunomodulatory agent for the treatment of neurodegenerative conditions

Generalized Transformation for Decorated Spin Models

The paper discusses the transformation of decorated Ising models into an effective \textit{undecorated} spin models, using the most general Hamiltonian for interacting Ising models including a long range and high order interactions. The inverse of a Vandermonde matrix with equidistant nodes $[-s,s]$ is used to obtain an analytical expression of the transformation. This kind of transformation is very useful to obtain the partition function of decorated systems. The method presented by Fisher is also extended, in order to obtain the correlation functions of the decorated Ising models transforming into an effective undecorated Ising models. We apply this transformation to a particular mixed spin-(1/2,1) and (1/2,2) square lattice with only nearest site interaction. This model could be transformed into an effective uniform spin-$S$ square lattice with nearest and next-nearest interaction, furthermore the effective Hamiltonian also include combinations of three-body and four-body interactions, particularly we considered spin 1 and 2.Comment: 16 pages, 4 figure

Implant of Port-o-Cath for antineoplastic chemotherapy in a canine: case report

O Port-o-Cath é um cateter venoso central totalmente implantável, o qual permite a infusão de quimioterápicos, hemoderivados, nutrição parenteral e coleta de sangue. Este trabalho relata o caso de um canino com um tumor no membro pélvico que foi tratado cirurgicamente e recebeu o cateter para a quimioterapia antineoplásica. A paciente possuía um sarcoma sinovial, tumor incomum em cães, que acomete normalmente as articulações e exige terapia multimodal. O tratamento foi feito em duas etapas; na primeira, o membro foi amputado e, na segunda, foi realizado o implante do Port-o-Cath e exérese de nódulo metastático. A cadela respondeu satisfatoriamente à cirurgia e realizou as sessões de quimioterapia com perfeito funcionamento do cateter, indo a óbito por outras causas 90 dias após o procedimento. O implante de Port-o-Cath para a quimioterapia é um grande aliado à terapia multimodal preconizada para o câncer, podendo o cateter ser considerado em pacientes que necessitem de medicação quimioterápica por longo período.The Port-a-Cath is a totally implantable central venous catheter that allows the infusion of chemotherapeutic agents, blood products, parenteral nutrition, and blood sample collection. This work reports the case of a dog with a tumor in the pelvic limb that was treated surgically and received the catheter for cancer chemotherapy. The patient was diagnosed with synovial sarcoma, an uncommon tumor in dogs that usually affects the joints and requires multimodal therapy. The treatment was done in two steps, in the first the limb was amputated and in the second the Port-a-Cath implantation and the excision of the metastatic nodule were performed. The dog responded well to surgery and chemotherapy sessions held with proper functioning of the catheter, and died from other causes 90 days after the procedure. The implantation of Port-a-Cath for chemotherapy is a great ally of multimodal therapy recommended for cancer, so this catheter may be considered for patients requiring chemotherapy medication for a long period

COVID-19 PICU guidelines: for high- and limited-resource settings

BACKGROUND: Fewer children than adults have been affected by the COVID-19 pandemic, and the clinical manifestations are distinct from those of adults. Some children particularly those with acute or chronic co-morbidities are likely to develop critical illness. Recently, a multisystem inflammatory syndrome (MIS-C) has been described in children with some of these patients requiring care in the pediatric ICU. METHODS: An international collaboration was formed to review the available evidence and develop evidence-based guidelines for the care of critically ill children with SARS-CoV-2 infection. Where the evidence was lacking, those gaps were replaced with consensus-based guidelines. RESULTS: This process has generated 44 recommendations related to pediatric COVID-19 patients presenting with respiratory distress or failure, sepsis or septic shock, cardiopulmonary arrest, MIS-C, those requiring adjuvant therapies, or ECMO. Evidence to explain the milder disease patterns in children and the potential to use repurposed anti-viral drugs, anti-inflammatory or antithrombotic therapies are also described. CONCLUSION: Brief summaries of pediatric SARS-CoV-2 infection in different regions of the world are included since few registries are capturing this data globally. These guidelines seek to harmonize the standards and strategies for intensive care that critically ill children with COVID-19 receive across the worl