Electrodeposition and characterization of nikel-copper metallic foams for application as electrodes for supercapacitors

Nickel-copper metallic foams were electrodeposited from an acidic electrolyte, using hydrogen bubble evolution as a dynamic template. Their morphology and chemical composition was studied by scanning electron microscopy and related to the deposition parameters (applied current density and deposition time). For high currents densities (above 1 A cm(-2)) the nickel-copper deposits have a three-dimensional foam-like morphology with randomly distributed nearly-circular pores whose walls present an open dendritic structure. The nickel-copper foams are crystalline and composed of pure nickel and a copper-rich phase containing nickel in solid solution. The electrochemical behaviour of the material was studied by cyclic voltammetry and chronopotentiometry (charge-discharge curves) aiming at its application as a positive electrode for supercapacitors. Cyclic voltammograms showed that the Ni-Cu foams have a pseudocapacitive behaviour. The specific capacitance was calculated from charge-discharge data and the best value (105 F g(-1) at 1 mA cm(-2)) was obtained for nickel-copper foams deposited at 1.8 A cm(-2) for 180 s. Cycling stability of these foams was also assessed and they present a 90 % capacitance retention after 10,000 cycles at 10 mA cm(-2).

Characterisation and electrochemical behaviour of electrodeposited Cu-Fe foams applied as pseudocapacitor electrodes

Copper iron (Cu-Fe) 3D porous foams for supercapacitor electrodes were electrodeposited in the cathodic regime, on stainless steel current collectors, using hydrogen bubbling dynamic template. The foams were prepared at different current densities and deposition times. The foams were submitted to thermal conditioning at temperatures of 150 and 250 degrees C. The morphology, composition and structure of the formed films were studied by SEM, EDS and XRD, respectively. The electrochemical behaviour was studied by cyclic voltammetry, electrochemical impedance spectroscopy and chronopotentiometry. The morphology of the 3D Cu-Fe foams is sensitive to the electrodeposition current and time. The increase of the current density produces a denser, larger and more ramified dendritic structure. Thermal conditioning at high temperature induces a coarser grain structure and the formation of copper oxides, which affect the electrochemical behaviour. The electrochemical response reveals the presence of various redox peaks assigned to the oxidation and reduction of Cu and Fe oxides and hydroxides in the foams. The specific capacitance of the 3D Cu Fe foams was significantly enhanced by thermal conditioning at 150 degrees C. The highest specific capacitance values attained 297 Fg(-1) which are much above the ones typically observed for single Cu or Fe Oxides and hydroxides. These values highlight a synergistic behaviour resulting from the combination of Cu and Fe in the form of nanostructured metallic foams. Moreover, the capacitance retention observed in an 8000 charge/discharge cycling test was above 66%, stating the good performance of these materials and its enhanced electrochemical response as supercapacitor negative electrodes. (C) 2014 Elsevier B.V. All rights reserved.

Upper Jurassic Hybodontidae (Selachii) from Lourinhã, Portugal

Hybodontidae teeth and spines from the Lourinha Formation, Sobral unit are described. These teeth and spines have been ascribed to the genus Hybodus and regarded as Hybodus cf. reticulatus.

Description de restes squelettiques de Latidae: Lates (?) sp. (Poissons téléostéens, Percoidei) du Miocène inférieur et moyen du bassin du Bas Tage (environs de Lisbonne, Portugal)

Several Lower and Middle Miocene localities in the Lower Tagus basin near Lisbon yielded Latidae fragmentary remnants. No really decisive character has been recognized that would allow us to state these remnants could surely be ascribed to the genus Lates Cuv. & Val., although we regard this as nearly certain. There are some differences between the Miocene latidae under study and the type species Lates niloticus L. this suggests us to report the concerned remnants to a Lates (?) sp. that could belong to a new, hitherto undescribed species. The occurrence of Lates in fluviatile or lagoonal beds in the Lower Tagus basin Miocene series is not at all surprising under a paleoeciological view point. Even less if account is taken of the presence in the same levels of Siluriforms remnants belonging to Bagridae and Ariidae, two families that are well represented in Africa. Bagrid spines have been found at Quinta das Pedreiras in association with Lates (?) sp. remnants. The Lates (?) sp. discovery in the Lower and Middle Miocene from the Lower Tagus basin results in extending to the West this genus' biogeographic distribution. It is indeed the first discovery of this genus on Europe's Atlantic coasts. No matter which was the geographic origin of these fishes, they had to migrate several hundreds of kilometers through marine waters before entering the Tagus' estuary. The association of Lates (?) sp. remnants with Siluriform ones that have an extant, broad repartition in Africa south of the Sahara points out to an African origin. These thermophyll fishes imigration along the Atlantic coasts from lberian Peninsula probably has been possible owing to a warm climatic event that allowed them to migrate ca. 5 degrees (in latitude) northwards in Burdigalian times.

Mathematical model for HIV dynamics in HIV-specific helper cells

In this paper we study a delay mathematical model for the dynamics of HIV in HIV-specific CD4 + T helper cells. We modify the model presented by Roy and Wodarz in 2012, where the HIV dynamics is studied, considering a single CD4 + T cell population. Non-specific helper cells are included as alternative target cell population, to account for macrophages and dendritic cells. In this paper, we include two types of delay: (1) a latent period between the time target cells are contacted by the virus particles and the time the virions enter the cells and; (2) virus production period for new virions to be produced within and released from the infected cells. We compute the reproduction number of the model, R0, and the local stability of the disease free equilibrium and of the endemic equilibrium. We find that for values of R0<1, the model approaches asymptotically the disease free equilibrium. For values of R0>1, the model approximates asymptotically the endemic equilibrium. We observe numerically the phenomenon of backward bifurcation for values of R0⪅1. This statement will be proved in future work. We also vary the values of the latent period and the production period of infected cells and free virus. We conclude that increasing these values translates in a decrease of the reproduction number. Thus, a good strategy to control the HIV virus should focus on drugs to prolong the latent period and/or slow down the virus production. These results suggest that the model is mathematically and epidemiologically well-posed.

Scanning electron microscopy of third-instar sarcophagid (Diptera: Sarcophagidae) recovered from a mummified human corpse in Thailand

The third-instar of an unidentified sarcophagid, recovered from a mummified body of a 32-yr-old Thai male was examined using scanning electron microscopy (SEM). Although the morphological features of this larva are similar to the other sarcophagid larvae, some features could be helpful for species identification, which is a basic requirement for estimation of postmortem interval in forensic investigation. These features included number and arrangement of papillae on the anterior spiracle, structure of spines, size of circumspiracular tubercles at caudal segment and branching peculiarity of the posterior spiracular hairs. This information could benefit future identification of the sarcophagid larvae that exist in Thailand.

The venomous toadfish Thalassophryne nattereri (niquim or miquim): report of 43 injuries provoked in fishermen of Salinópolis (Pará State) and Aracaju (Sergipe State), Brazil

Fishes of family Batrachoididae are responsible for great number of injuries in fishermen in North and Northeast regions of Brazil. The genus Thalassophryne presents various venomous species of fishes found in the Brazilian coast, T. nattereri being the most common of them. The venom is ejected through two hollow spines on the dorsal fin and two on pre-opercular regions, which present a venomous gland in the base and can be erected or depressed by the fish. The manifestations of the envenoming were intense local pain, edema and erythema in 43 patients observed in Salinópolis (Pará State) and Aracaju (Sergipe State). There were no systemic manifestations, but necrosis was detected in eight and bacterial infection in ten injured fishermen. The circumstances of the contacts and therapeutic aspects are discussed. Envenoming by the genus Thalassophryne is important and frequent and should be considered of moderate severity grade, since there are not the excruciating pain or the massive local necrosis provoked by scorpionfishes (Scorpaena) or stingrays injuries nor the systemic manifestations that are the most important marker of severe envenoming.

Some ultrastructural superficial changes in house fly (Diptera: Muscidae) and blow fly (Diptera: Calliphoridae) larvae induced by eucalyptol oil

The ultrastructural superficial changes in third instar house fly (Musca domestica) and blow fly (Chrysomya megacephala) induced by eucalyptol oil were observed using scanning electron microscopy. Dipped in 0.902 g/ml eucalyptol for 30 sec, the larvae integument of both species showed significant aberrant appearance of the body surface, particularly swelling integument, bleb formation, partial breach and deformation of spines.

Sea urchin granuloma

Injuries caused by venomous and poisonous aquatic animals may provoke important morbidity in humans. The phylum Echinoderma include more than 6000 species of starfish, sea urchins, sand dollars, and sea cucumbers some of which have been found responsible for injuries to humans. Initial injuries by sea urchins are associated with trauma and envenomation, but later effects can be observed. Sea urchin granuloma is a chronic granulomatous skin disease caused by frequent and successive penetration of sea urchin spines which have not been removed from wounds. The authors report a typical case of sea urchin granuloma in a fisherman and its therapeutic implications.

Case for Diagnosis

Blastic plasmacytoid dendritic cell tumor is a rare, highly aggressive systemic neoplasm for which effective therapies have not yet been established. We describe a 73-year-old man with multiple nodules and patches emerging on the trunk and limbs. Lesional skin biopsy revealed a plasmacytoid dendritic cell tumor with dense dermal infiltrate of tumor cells with blastoid features. No apparent systemic involvement was identified in the initial stage. The patient was treated with prednisone daily, with notorious improvement of the skin lesions, although no complete remission was obtained. During the six-month follow-up period, no disease progression was documented, but fatal systemic progression occurred after that period of time.

Expression of TLR2 and TLR4 in lesions of patients with tegumentary american leishmaniasis

OBJECTIVES: The aim of this study was to describe the pattern of expression of Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) in skin biopsies of patients with American tegumentary leishmaniasis (ATL) caused by Leishmania braziliensis. METHODS: This prospective study evaluated 12 patients with ATL caused by Leishmania braziliensis confirmed by polymerase chain reaction. Immunohistochemistry was performed to determine the expression of TLR2 and TLR4. The number of NK cells, dendritic cells and macrophages in the tissue were calculated. The cytokine expression was determined using the anti-TNF-α, anti-IFN-Γ, anti-IL-1 and anti-IL-6. Double immunostaining reactions were used to determine the cell expressing TLR2 and TLR4. RESULTS: The numbers of cells expressing TLR2 and TLR4 were 145.48 ± 82.46 cell/mm² and 3.26 ± 4.11 cell/mm² respectively (p < 0.05). There was no correlation of TLR2 and TLR4 with the amount of cytokines and the number of NK cells, dendritic cells or macrophages. The double immunostaining revealed that TLR2 was expressed by macrophages. CONCLUSION: In human cutaneous leishmaniasis caused by Leishmania braziliensis, TLR2 is the most common TLR expressed during active disease, mainly by macrophages although without correlation with the amount of cytokines and number of cells.

Sialyl Tn-Expressing Bladder Cancer Cells Induce a Tolerogenic Phenotype in Innate and Adaptive Immune Cells

Despite the wide acceptance that glycans are centrally implicated in immunity, exactly how they contribute to the tilt immune response remains poorly defined. In this study, we sought to evaluate the impact of the malignant phenotype-associated glycan, sialyl-Tn (STn) in the function of the key orchestrators of the immune response, the dendritic cells (DCs). In high grade bladder cancer tissue, the STn antigen is significantly overexpressed and correlated with the increased expression of ST6GALNAC1 sialyltransferase. Bladder cancer tissue presenting elevated expression of ST6GALNAC1 showed a correlation with increased expression of CD1a, a marker for bladder immature DCs and showed concomitant low levels of Th1-inducing cytokines IL-12 and TNF-α. In vitro, human DCs co-incubated with STn+ bladder cancer cells, had an immature phenotype (MHC-IIlow, CD80low and CD86low) and were unresponsive to further maturation stimuli. When contacting with STn+ cancer cells, DCs expressed significantly less IL-12 and TNF-α. Consistent with a tolerogenic DC profile, T cells that were primed by DCs pulsed with antigens derived from STn+ cancer cells were not activated and showed a FoxP3high IFN-γlow phenotype. Blockade of STn antigens and of STn+ glycoprotein, CD44 and MUC1, in STn+ cancer cells was able to lower the induction of tolerance and DCs become more mature. Overall, our data suggest that STn-expressing cancer cells impair DC maturation and endow DCs with a tolerogenic function, limiting their capacity to trigger protective anti-tumour T cell responses. STn antigens and, in particular, STn+ glycoproteins are potential targets for circumventing tumour-induced tolerogenic mechanisms.

Establishing a cell biology platform: isolation and preservation of human blood products

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Sporothrix schenckii associated with armadillo hunting in Southern Brazil: epidemiological and antifungal susceptibility profiles

INTRODUCTION: Sporotrichosis is the most common subcutaneous mycosis observed in Brazil and it is generally consequent to a little trauma caused by vegetal particles or spines which inoculate the fungi in the subcutaneous area. Although sporotrichosis had been frequently mentioned with armadillo hunting this form has not been widely reported in Brazil until now. In this study we report ten cases of sporotrichosis evolving the armadillo's hunting diagnosed in some towns located in the central and west regions of Rio Grande do Sul State. METHODS: The cases were established based on clinical and classic mycological laboratorial techniques. The susceptibility tests were conducted by microdilution technique according to M38-A2 CLSI documents. RESULTS: Ten cases of sporotrichosis associated with armadillo hunting detected in the State of Rio Grande do Sul were diagnosed by mycological methods. The susceptibility tests of Sporothrix schenckii isolates to antifungal agents itraconazole, ketoconazole and terbinafine showed that all the isolates were susceptible. CONCLUSIONS: The paper discusses some cultural aspects related to hunting of this wild animal as well as possible causes of this unexpected occurrence in southern Brazil.

Ultrastructural study on the morphological changes to male worms of Schistosoma mansoni after in vitro exposure to allicin

INTRODUCTION: Garlic has a wide range of actions, including antibacterial, antiviral, antifungal, antiprotozoal and anthelmintic actions. This antiparasitic activity has been attributed to allicin, which is the main constituent of garlic. The present study aimed to investigate the in vitro activity of allicin on the tegument of adult Schistosoma mansoni worms using scanning electron microscopy. METHODS: Swiss Webster mice were infected with S. mansoni cercariae (100 per mouse) and sacrificed 50 days later to acquire the adult worms. These worms were collected by perfusion and placed in RPMI medium 1,640 at 37°C before transferring to RPMI media containing 0 (control), 5, 10, 15 and 20mg/mL of allicin, where they were incubated for 2h. The worms were fixed in 2.5% glutaraldehyde solution, washed twice, post-fixed in osmium tetroxide, washed twice and then dehydrated with ascending grades of ethanol. The samples were air-dried, mounted on stubs, gold coated in an ion sputtering unit and viewed using a scanning electron microscope. RESULTS: A concentration of 5mg/mL caused wrinkling in the tegument; a concentration of 10mg/mL resulted in changes to tubercles and loss or modification of spines. With 15 and 20mg/mL increasing damage to the tegument could be seen, such as vesicle formation and the presence of ulcers. CONCLUSIONS: These findings demonstrate the effect of allicin on adult S. mansoni worms and indicate that most of the changes occur at concentrations greater than that normally indicated for treatment.