Oxidative Stress and Modification of Renal Vascular Permeability Are Associated with Acute Kidney Injury during P. berghei ANKA Infection

Malaria associated-acute kidney injury (AKI) is associated with 45% of mortality in adult patients hospitalized with severe form of the disease. However, the causes that lead to a framework of malaria-associated AKI are still poorly characterized. Some clinical studies speculate that oxidative stress products, a characteristic of Plasmodium infection, as well as proinflammatory response induced by the parasite are involved in its pathophysiology. Therefore, we aimed to investigate the development of malaria-associated AKI during infection by P. berghei ANKA, with special attention to the role played by the inflammatory response and the involvement of oxidative stress. For that, we took advantage of an experimental model of severe malaria that showed significant changes in the renal pathophysiology to investigate the role of malaria infection in the renal microvascular permeability and tissue injury. Therefore, BALB/c mice were infected with P. berghei ANKA. To assess renal function, creatinine, blood urea nitrogen, and ratio of proteinuria and creatininuria were evaluated. The products of oxidative stress, as well as cytokine profile were quantified in plasma and renal tissue. The change of renal microvascular permeability, tissue hypoxia and cellular apoptosis were also evaluated. Parasite infection resulted in renal dysfunction. Furthermore, we observed increased expression of adhesion molecule, proinflammatory cytokines and products of oxidative stress, associated with a decrease mRNA expression of HO-1 in kidney tissue of infected mice. The measurement of lipoprotein oxidizability also showed a significant increase in plasma of infected animals. Together, our findings support the idea that products of oxidative stress, as well as the immune response against the parasite are crucial to changes in kidney architecture and microvascular endothelial permeability of BALB/c mice infected with P. berghei ANKA.State of Sao Paulo Foundation for Research Support (FAPESP)State of Sao Paulo Foundation for Research Support (FAPESP) [07/07139-3, 10/52180-4, 12/02270-2]CAPESCAPESBrazilian Council of Scientific and Technologic Development (International Associated Laboratory of Renal Immunopathology, CNPq/Inserm)Brazilian Council of Scientific and Technologic Development (International Associated Laboratory of Renal Immunopathology, CNPq/Inserm)Complex Fluids INCT (FAPESP/CNPq)Complex Fluids INCT (FAPESP/CNPq

Synthesis and optical spectroscopy of Nd3+ and Sm3+ doped stable phases in the system Y2O3-Al2O3

Submitted by Jaqueline Silva ([email protected]) on 2014-12-29T19:00:53Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação-Tarcio de Castro Silva-2013.pdf: 2977225 bytes, checksum: fd526c61a432b30b5d2e995e06a97c2d (MD5)Approved for entry into archive by Jaqueline Silva ([email protected]) on 2014-12-29T19:01:04Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação-Tarcio de Castro Silva-2013.pdf: 2977225 bytes, checksum: fd526c61a432b30b5d2e995e06a97c2d (MD5)Made available in DSpace on 2014-12-29T19:01:04Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação-Tarcio de Castro Silva-2013.pdf: 2977225 bytes, checksum: fd526c61a432b30b5d2e995e06a97c2d (MD5) Previous issue date: 2013-11-28Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESThe development of rare earths luminescent materials has been subject of many research works searching for technological applications in the manufacture of solid-state lasers, photonic and biomedical devices, manufacturing of displays, and others. The system Y2O3-Al2O3 has three stable crystalline phases: Y3Al5O12 (YAG), YAlO3 (YAP) and Y4Al2O9 (YAM). Among them, YAP and YAG are widely studied and used in the manufacture of solid-state lasers. In this work, we used the modified polymeric precursor method to synthesize YAG, YAP, and YAM doped with 0.5 and 1% of Nd3+ and Sm3+ ions replacing Y3+. Analysis of X ray diffraction and vibrational spectroscopy confirmed the achievement of crystalline single phases. Transmission electron images show grain sizes ranging from 80 to 300 nm. We verified a strong influence of the different matrices symmetries on the optical emission of these rare earths photoluminescent ions.O desenvolvimento de materiais luminescentes dopados com terras raras tem sido alvo de muitas pesquisas para aplicações em diversas áreas como na fabricação de lasers de estado sólido, em fotônica, fabricação de displays, aplicações médicas e outros. Matrizes no sistema Y2O3-Al2O3 têm se mostrado interessantes para hospedar centros luminescentes. Este sistema possui três fases cristalinas estáveis: Y3Al5O12 (YAG), YAlO3 (YAP) e Y4Al2O9 (YAM); dentre elas, o YAP e YAG são amplamente estudadas e utilizadas para fabricação de lasers do estado sólido. Neste trabalho, utilizando o método de precursores poliméricos, sintetizamos essas três fases dopadas com os terras raras Nd3+ e Sm3+ em concentrações de 0,5 e 1% de substituição de átomos de Y3+. Análises de difrações de raios X e absorção no infravermelho confirmaram a obtenção das fases cristalinas. Imagens de microscopia eletrônica de transmissão mostram tamanho de grãos entre 80 e 300nm. Através das análises de fotoluminescência, verificamos forte dependência dos espectros de emissão com as simetrias dos sítios cristalinos das três matrizes

Photoluminescence of Ag+ and Ag m n+ in co-doped Pr3+/Yb3+ fluorophosphate glasses: tuning visible emission and energy transfer to Pr3+/Yb3+ ions through excitation in different silver species

Here, we report the luminescence properties of Yb3+/Pr3+ dual-doped fluorophosphate glasses containing silver clusters. Through the solubility of silver into the glass system as function of its initial concentration, charged species characterized as Ag+ and Ag m n+ were formed and identified according to their absorption and emission spectral responses. By changing the transition metal concentration, multi-energy transfer mechanisms were observed between silver and Yb3+/Pr3+ co-doped glasses. The stabilization of silver species seems to be detrimental to the radiative processes of the rare earth ions under excitation at 444 nm (Pr3+3H4 → 3P0 absorption line). In other words, the main visible emissions of Pr3+ and the NIR emission of Yb3+ decrease with increment of Ag concentration. However, energy transfer occurs for large spectral range by the excitation of the silver species. In consequence, the visible and NIR emission could be activate in a broadband from ultraviolet to the blue part of the spectral region. These two observations highlight the competitive absorption processes and probabilities between the cationic elements and the interest to use the transition metal species as sensitizers to excite the rare earth elements.Initiative d'excellence de l'Université de Bordeau

Tuning multicolor emission in AgNCs/Tm3+/Mn2+-doped fluorophosphate glasses

Herein we report the synthesis of highly-doped silver nanocluster in fluorophosphate glasses through the melting-quenching method in order to achieve sensitization with Tm3+ and Mn2+ ions. Blue and red emission belonging to Tm3+ (470 to 490 nm) and Mn2+ (550 to 750 nm) ions could be obtained via non-resonant excitation of Tm3+ and Mn2+. Slight decrease of the fluorescence decay times confirmed an energy transfer as a possible mechanism to explain the Tm3+ and Mn2+ emission. The composition of 5 mol% of AgNO3, 0.4 mol% of Tm2O3 and 0.2 mol% of MnF2 in our sample leads to distance between donor (silver nanoclusters) and acceptor (Tm3+-Mn2+) as short as 11 \uc5, which suggests that the main mechanism for blue and red emission from Tm3+ and Mn2+ is F\uf6rster Resonance Energy Transfer (FRET). The results presented here show that the studied material has potential application for multicolor generation as luminophore in white light emitting diodes (W-LED)

Control of powers for wind power generation and grid current harmonics filtering from doubly fed induction generator: comparison of two strategies

Two strategies for wind power systems that simultaneously adjust the powers generation from doubly fed induction generator and achieves grid currents harmonic filtering are presented in this paper. The harmonic mitigation function is developed by algorithms proposed for compensating harmonics from the grid side converter. The quality of power is substantially enhanced. The generator side converter regulates the active and reactive powers that are supplied to the electric grid by the stator flux oriented control. This paper presents a novel control system for power generation and electric grid harmonic compensation, which is described and validated through comparison with other strategies. A harmonic filtering behavior analysis for some operation points using the novel strategy is presented. The proposed system efficiency is verified through simulation and experimental results. The grid current THD when none of the proposed strategies are applied is 17.21%. The THD is reduced to 5.68% when strategy 1 is applied. When strategy 2 is used the THD is decreased to 3.18%73270332713FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP2017/21640-9; 15/03248-9; 16/08645-

Femtosecond laser micro-patterning of optical properties and functionalities in novel photosensitive silver-containing fluorophosphate glasses

Silver-containing glasses are promising candidates for photonic applications, due to the potentiality of spectroscopic properties of silver nanoclusters (NC's) and/or silver metallic nanoparticles. In this framework, silver-containing fluorophosphate glasses are candidates with a strong potential. Indeed, combined with femtosecond laser irradiation, silver NC's may be tailored in three-dimensional fluorescent micro-structures, whose spectroscopic properties have been investigated, revealing the creation of silver NC's but also of NP's during laser irradiation in the studied fluorophosphate glass. Additionally, the photo-inscription of silver NC's is correlatively accompanied by a positive index change, which has led to the demonstration of optical waveguiding behavior. Finally, the management of the reservoir of available silvers for laser inscription is investigated. Unlike previous observations made in standard oxide phosphate glasses, the considered silver-containing fluorophosphate glass exhibes an intriguing ability to be re-written when subjected to successive overlapping laser irradiations. Upon the optimization of compositions with tailored photo-sensitivity, the re-writable ability of fluorophosphate glasses paves the way to the design of advanced photonic devices such as photonic optical circuits, evanescent sensors or 3D high-density optical data storage.Initiative d'excellence de l'Université de BordeauxImPRession laser de fibres exOtiques Multi-MaTEriau

The ELIMAIA Laser–Plasma Ion Accelerator: technological commissioning and perspectives

We report on the technological commissioning of the Laser–Plasma Ion Accelerator section of the ELIMAIA user beamline at the ELI Beamlines facility in the Czech Republic. The high-peak, high-average power L3-HAPLS laser system was used with an energy of ~10 J and pulse duration of ~30 fs on target, both in single-pulse and high repetition-rate (~0.5 Hz) mode. The laser pulse was tightly focused to reach ultrahigh intensity on target (~1021 W/cm2) and sustain such laser–plasma interaction regime during high repetition-rate operations. The laser beam, ion beam, and laser–plasma emission were monitored on a shot-to-shot basis, and online data analysis at 0.5 Hz was demonstrated through the full set of used diagnostics (e.g., far and near field, laser temporal diagnostics, X- and gamma-ray detectors, Thomson Parabola ion spectrometer, time-of-flight ion detectors, plasma imaging, etc.). The capability and reliability of the ELIMAIA Ion Accelerator was successfully demonstrated at a repetition rate of 0.5 Hz for several hundreds of consecutive laser shots

Evaluation of hypoxia, HIF-1α in renal tissue and apoptosis during malaria-associated AKI.

<p>(A) Representative immunohistochemistry, and (B) quantification of renal hypoxia in control and <i>P. berghei</i> ANKA infected mice. (C) mRNA expression of HIF-1α in renal tissue. (D) Evaluation of apoptosis in kidney section of control and <i>P. berghei</i> ANKA infected mice. Each graph represents the mean of 5–10 animals per group ± standard deviation. One-way ANOVA with Bonferroni post-test was performed using GraphPad Prism. * P<0.05 vs control group – day 0, ** p<0.01 vs control group – day 0.</p

Analysis of sequestration of infected red blood cell in renal tissue.

<p>(A) Representative figure of presence of malaria pigment hemozoin in renal tissue sections visualized by hematoxylin and eosin, or under polarized light. Detection of hemozoin at glomeruli (<b>i</b>) and vascular endothelium (<b>ii</b>). (B) Hemozoin quantification in histological section of renal tissue. (C) <i>P. berghei</i> ANKA mRNA quantified by qPCR in renal tissue of BALB/c infected mice. Each graph represents the mean of 5–10 animals per group ± standard deviation. One-way ANOVA with Bonferroni post-test was performed using GraphPad Prism. *** p<0.001 vs. the control group – day 0, # p<0.01 vs. day 12.</p