Cobalt(III) complexes with thiosemicarbazones as potential anti-Mycobacterium tuberculosis agents

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Degradation of dipyrone by electrogenerated H2O2 combined with Fe2+ using a modified gas diffusion electrode

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Infrared to visible up-conversion in biocellulose yttrium vanadate nanoparticle composite membranes. Demonstration of chloroaluminum phthalocyanine light emission under up-converted light excitation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antimicrobial photodynamic therapy against pathogenic bacterial suspensions and biofilms using chloro-aluminum phthalocyanine encapsulated in nanoemulsions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sensores eletroquímicos à base de nanomateriais carbonáceos e catalisadores biomiméticos para determinação de tetraciclina em diferentes tipos de amostras

Pós-graduação em Química - IQ

Single precursor route to efficient cobalt sulphide counter electrodes for dye sensitized solar cells

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effects of humidity on the electrical properties of thermal inkjet-printed films of copper tetrasulfonated phthalocyanine (CuTsPc) onto paper substrates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Thermal inkjet printing of copper tetrasulfonated phthalocyanine (CuTsPc) as a semiconducting layer on flexible MIS capacitors

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Preparation and thermal decomposition of solid state cobalt, nickel, copper and zinc chelates of ethylenediaminetetraacetic acid

Solid state chelates of general formula H-2[M(EDTA)] . nH2O, where M is Co, Ni, Cu or Zn, and EDTA is ethylenediaminetetraacetate, were prepared. Thermogravimetry-derivative thermogravimetry (TG-DTG), differential thermal analysis (DTA) and complexometry were used to characterize and to study the thermal stability and thermal decomposition of these compounds.

Correlation between i.r. spectra and thermal decomposition of cobalt(II), nickel(II), copper(II) and mercury(II) complexes with piperidinedithiocarbamate and pyrrolidinedithiocarbamate

The thermal decomposition of pyrrolidinedithiocarbamate and piperidinedithiocarbamate complexes of CoII, NiII, CuII and HgII have been studied by thermogravimetry and differential scanning calorimetry. The decomposition intermediates and final products were identified by their X-ray diffraction patterns. The i.r. spectra are discussed in terms of the thermal decomposition pathways.

Influence of polyaniline and phthalocyanine hole-transport layers on the electrical performance of light-emitting diodes using MEH-PPV as emissive material

The influence of layer-by-layer films of polyaniline and Ni-tetrasulfonated phthalocyanine (PANI/Ni-TS-Pc) on the electrical performance of polymeric light-emitting diodes (PLED) made from (poly[2-methoxy-5-(2`-ethyl-hexyloxy)-1,4-phenylene vinylene]) (MEH-PPV) is investigated by using current versus voltage measurements and impedance spectroscopy. The PLED is composed by a thin layer of MEH-PPV sandwiched between indium tin oxide (ITO) and aluminum electrodes, resulting in the device structure ITO/(PANI/Ni-TS-Pc)(n)/MEH-PPV/Al, where n stands for the number of PANI/Ni-TS-Pc bilayers. The deposition of PANI/Ni-TS-Pc leads to a decrease in the driving voltage of the PLEDs, which reaches a minimum when n = 5 bilayers. In addition, impedance spectroscopy data reveal that the PLED impedance decreases as more PANI/Ni-TS-Pc bilayers are deposited. The PLED structure is further described by an equivalent circuit composed by two R-C combinations, one for the bulk and other for the interface components, in series with a resistance originated in the ITO contact. From the impedance curves, the values for each circuit element is determined and it is found that both, bulk and interface resistances are decreased upon PANI/Ni-TS-Pc deposition. The results indicate that PANI/NiTS-Pc films reduce the contact resistance at ITO/MEH-PPV interface, and for that reason improve the hole-injection within the PLED structure. (c) 2007 Elsevier B.V. All rights reserved.

Development, characterization, and in vitro trials of chloroaluminum phthalocyanine-magnetic nanoemulsion to hyperthermia and photodynamic therapies on glioblastoma as a biological model

A glioblastoma multiforme (GBM) is the highest grade glioma tumor (grade IV) and is the most malignant form of astrocytomas. Grade IV tumors, which are the most malignant and aggressive, affect people between the ages of 45 and 70 years. A GBM exhibits remarkable characteristics that include excessive proliferation, necrosis, genetic instability, and chemoresistance. Because of these characteristics, GBMs are difficult to treat and have a poor prognosis with a median survival of less than one year. New methods to achieve widespread distribution of therapeutic agents across infiltrative gliomas significantly improve brain tumor therapy. Photodynamic therapy (PDT) and hyperthermia (HPT) are well-established tumor therapies with minimal side effects while acting synergistically. This study introduces a new promising nanocarrier for the synergistic application of PDT and magnetic hyperthermia therapy against human glioma cell line T98 G, with cellular viability reduction down to as low as 17% compared with the control. (C) 2012 American Institute of Physics. [doi:10.1063/1.3671775]

In Vitro Photodynamic Inactivation of Cryptococcus neoformans Melanized Cells with Chloroaluminum Phthalocyanine Nanoemulsion

The selection of fungi resistant to currently used fungicides and the emergence of new pathogenic species make the development of alternative fungus-control techniques highly desirable. Photodynamic antimicrobial chemotherapy (PACT) is a promising method which combines a nontoxic photosensitizer (PS) with visible light to cause selective killing of microbial cells. The development of PACT to treat mycoses or kill fungi in the environment depends on identifying effective PS for the different pathogenic species and delivery systems able to expand and optimize their use. In the present study, the in vitro susceptibility of Cryptococcus neoformans melanized cells to the photodynamic effects of the PS agent ClAlPc in nanoemulsion (ClAlPc/NE) was examined. Cells were killed in a PS concentration- and light dose-dependent manner. Treatment with ClAlPc/NE, using PS concentrations (e.g. 4.5 mu m) and light doses (e.g. 10 J cm-2) compatible with PACT, resulted in a reduction of up to 6 logs in survival. Washing the cells to remove unbound PS before light exposure did not inhibit fungal photodynamic inactivation. Internalization of ClAlPc by C.neoformans was confirmed by confocal fluorescence microscopy, and the degree of uptake was dependent on PS concentration.

Ethanol steam reforming over rhodium and cobalt-based catalysts: Effect of the support

The effect of support on the properties of rhodium and cobalt-based catalysts for ethanol steam reforming was studied in this work, by comparing the use of magnesia, alumina and Mg-Al oxide (obtained from hydrotalcite) as supports. It was found that metallic rhodium particles with around 2.4-2.6 nm were formed on all supports, but Mg-Al oxide led to the narrowest particles size distribution; cobalt was supposed to be located on the support, affecting its acidity. Rhodium interacts strongly with the support in the order: alumina> Mg-Al oxide > magnesia. The magnesium-containing catalysts showed low ethene selectivity and high hydrogen selectivity while the alumina-based ones showed high ethene selectivity, assigned to the Lewis sites of alumina. The Mg-Al oxide-supported rhodium and cobalt catalyst was the most promising sample to produce hydrogen by ethanol reforming, showing the highest hydrogen yield, low ethene selectivity and high specific surface area during reaction. Copyright (C) 2011, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Field dependent transition to the non-linear regime in magnetic hyperthermia experiments: Comparison between maghemite, copper, zinc, nickel and cobalt ferrite nanoparticles of similar sizes

Further advances in magnetic hyperthermia might be limited by biological constraints, such as using sufficiently low frequencies and low field amplitudes to inhibit harmful eddy currents inside the patient's body. These incite the need to optimize the heating efficiency of the nanoparticles, referred to as the specific absorption rate (SAR). Among the several properties currently under research, one of particular importance is the transition from the linear to the non-linear regime that takes place as the field amplitude is increased, an aspect where the magnetic anisotropy is expected to play a fundamental role. In this paper we investigate the heating properties of cobalt ferrite and maghemite nanoparticles under the influence of a 500 kHz sinusoidal magnetic field with varying amplitude, up to 134 Oe. The particles were characterized by TEM, XRD, FMR and VSM, from which most relevant morphological, structural and magnetic properties were inferred. Both materials have similar size distributions and saturation magnetization, but strikingly different magnetic anisotropies. From magnetic hyperthermia experiments we found that, while at low fields maghemite is the best nanomaterial for hyperthermia applications, above a critical field, close to the transition from the linear to the non-linear regime, cobalt ferrite becomes more efficient. The results were also analyzed with respect to the energy conversion efficiency and compared with dynamic hysteresis simulations. Additional analysis with nickel, zinc and copper-ferrite nanoparticles of similar sizes confirmed the importance of the magnetic anisotropy and the damping factor. Further, the analysis of the characterization parameters suggested core-shell nanostructures, probably due to a surface passivation process during the nanoparticle synthesis. Finally, we discussed the effect of particle-particle interactions and its consequences, in particular regarding discrepancies between estimated parameters and expected theoretical predictions. Copyright 2012 Author(s). This article is distributed under a Creative Commons Attribution 3.0 Unported License. [http://dx.doi. org/10.1063/1.4739533]