Publications

2018
Garcia A\'ısioM, Magalhes FL, Soares JS, Junior EP, de Lima MFR, Mamede M, de Paula AM. Second harmonic generation imaging of the collagen architecture in prostate cancer tissue. Biomedical Physics & Engineering Express [Internet]. 2018;4 (2) :025026. Publisher's VersionAbstract
Optical microscopy has been one of the most important tools for visualizing biological samples since the seventeenth century. Recently, with the advances in femtosecond laser technology, all the nonlinear optical processes have now been included as optical microscopy methods, and second harmonic generation (SHG) microscopy has emerged as a powerful new optical imaging tool with applications in medicine and biology. Here we use SHG microscopy to obtain images of 76 prostate biopsies on histological slides. Multiple samples from the excised prostates of patients who underwent a radical prostatectomy were evaluated. The samples were collected from prostate positions as in needle biopsy procedures. The results show the collagen fiber architecture among malignant acini, and analysis of the fiber orientation in the images reveals that the collagen fibers become more aligned at higher malignancy grades. Furthermore, we find that the degree of fiber alignment correlates directly with the Gleason patterns.
de Felipe L. Magalhães, Alexei M. C. Machado EPSKSAMPAMGIBJSSMM. Raman spectroscopy with a 1064-nm wavelength laser as a potential molecular tool for prostate cancer diagnosis: a pilot study. Journal of Biomedical Optics [Internet]. 2018;23 (12) :1 - 6 - 6. Publisher's Version
Manhabosco SM, Manhabosco TM, Geoffroy N, Vignal V, Dick LFP. Corrosion behaviour of galvanized steel studied by electrochemical microprobes applied on low-angle cross sections. Corrosion Science [Internet]. 2018;140 :379 - 387. Publisher's VersionAbstract
The combined use of the microcapillary cell (MEC) and scanning vibrating electrode technique (SVET) and low-angle cross sections was employed to elucidate the role of each coating region on the protection of the cut-edge corrosion of galvanized steels. Different compounds are involved in the blocking action of the corrosion products: Zincite (ZnO) on the steel substrate, hydrozincite (Zn5(OH)6(CO3)2) at the coating/steel interface, and Simonkolleite (Zn5(OH)8Cl2) and ZnO on the different coating regions in different proportions. The coating surface is also active at the initial stage and during long-term protection and thus, must be considered in experimental simulation of the cut-edge corrosion.
Nhavene EPF, da Silva WM, Junior RRT, Gastelois PL, Venâncio T, Nascimento R, Batista RJC, Machado CR, de Macedo WAA, de Sousa EMB. Chitosan grafted into mesoporous silica nanoparticles as benznidazol carrier for Chagas diseases treatment. Microporous and Mesoporous Materials [Internet]. 2018;272 :265 - 275. Publisher's VersionAbstract
The use of chitosan functionalized silica for benznidazole delivery in the treatment of neglected disease such as Chagas disease is one of the forms not yet explored, but with great potential for this therapy, as little is known about nanoformulations for the treatment of Chagas disease. In this work, we used chitosan-succinate covalently attached to the surface pore of MSNs to act as anchor for benznidazole as a delivery system. The samples were characterized structurally and chemically with multiple techniques. The applicability of functionalized MSNs as platforms for benznidazole delivery into T. cruzi parasites was assessed. The results demonstrate that the proposed system is a potential promising nanoplatform for drug and gene delivery targeting neglected diseases such as Chagas disease.
Azevedo MLS, Silveira BM, Novack KM, Barboza APM, Neves BRA, M. R. dos Santos V. Study of Controlled Release of PMMA-g-PEG Copolymer and Derivatives Incorporated with the Indomethacin Drug. Macromolecular Symposia [Internet]. 2018;381 (1) :1800145. Publisher's VersionAbstract
Synthetic polymers are made up of repeated monomeric units, and this gives them a very versatile appearance, making them useful in many areas of science. One is the pharmaceutical, which correlates the properties of the polymer with the active principle, so they can be used as an excipient or in the controlled release system. The PMMA-g-PEG4000 has characteristics derived from its precursors, that are pharmacologically active. When we incorporate drugs into this structure, the polymer can act on the controlled release, lessening the toxic character of the drug and producing fewer side effects. In this work, incorporations of the drug indomethacin were made in the PMMA-g-PEG copolymer and derivatives (PMMA-g-PEG4000 ETIL and PMMA-g-PEG4000 ACET). The samples were characterized by infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), thermogravimetric analysis (TGA), and atomic force microscopy (AFM) measurements. For each sample, the controlled release was performed in a total time of 4 h and the efficiency of the modified structures was verified.
Araujo KAS, Cury LA, Matos MJS, Fernandes TFD, cado LGC\c, Neves BRA. Electro-optical interfacial effects on a graphene/π-conjugated organic semiconductor hybrid system. Beilstein Journal of Nanotechnology. 2018;9 :963-974.
Ferrari GA, de Oliveira AB, Silvestre I, Matos MJS, Batista RJC, Fernandes TFD, Meireles LM, Eliel GSN, Chacham H, Neves BRA, et al. Apparent Softening of Wet Graphene Membranes on a Microfluidic Platform. ACS Nano [Internet]. 2018;12 (5) :4312-4320. Publisher's Version
Barboza APM, Matos MJS, Chacham H, Batista RJC, de Oliveira AB, Mazzoni MSC, Neves BRA. Compression-Induced Modification of Boron Nitride Layers: A Conductive Two-Dimensional BN Compound. ACS Nano [Internet]. 2018 :null. Publisher's Version
de Sousa TASL, Fernandes TFD, Matos MJS, Araujo END, Mazzoni MSC, Neves BRA, Plentz F. Thionine Self-Assembled Structures on Graphene: Formation, Organization, and Doping. Langmuir [Internet]. 2018;34 (23) :6903-6911. Publisher's Version
de Brito ACF, Correa RS, Pinto AA, Matos MJS, Tenorio JC, Taylor JG, Cazati T. Synthesis, crystal structure, photophysical properties and theoretical studies of a novel bis(phenylisoxazolyl) benzene derivative. Journal of Molecular Structure [Internet]. 2018 :-. Publisher's VersionAbstract
Abstract Isoxazoles have well established biological activities but, have been underexplored as synthetic intermediates for applications in materials science. The aims of this work are to synthesis a novel isoxazole and analyze its structural and photophysical properties for application in electronic organic materials. The novel bis (phenylisoxazolyl) benzene compound was synthesized in four steps and characterized by NMR, high resolution mass spectrometry, differential thermal analysis, infrared spectroscopy, cyclic voltammetry, ultraviolet–visible spectroscopy, fluorescence spectroscopy, \DFT\ and \TDDFT\ calculations. The molecule presented optical absorption in the ultraviolet region (from 290 nm to 330 nm), with maximum absorption length centered at 306 nm. The molar extinction coefficients (ε), fluorescence emission spectra and quantum efficiencies in chloroform and dimethylformamide solution were determined. Cyclic voltammetry analysis was carried out for estimating the \HOMO\ energy level and these properties make it desirable material for photovoltaic device applications. Finally, the excited-state properties of present compound were calculated by time-dependent density functional theory (TDDFT).
Chacham H, Barboza APM, de Oliveira AB, de Oliveira CK, Batista RJC, Neves BRA. Universal deformation pathways and flexural hardening of nanoscale 2D-material standing folds. Nanotechnology [Internet]. 2018;29 (9) :095704. Publisher's VersionAbstract
In the present work, we use atomic force microscopy nanomanipulation of 2D-material standing folds to investigate their mechanical deformation. Using graphene, h-BN and talc nanoscale wrinkles as testbeds, universal force–strain pathways are clearly uncovered and well-accounted for by an analytical model. Such universality further enables the investigation of each fold bending stiffness κ as a function of its characteristic height h 0 . We observe a more than tenfold increase of κ as h 0 increases in the 10–100 nm range, with power-law behaviors of κ versus h 0 with exponents larger than unity for the three materials. This implies anomalous scaling of the mechanical responses of nano-objects made from these materials.
Dias RF, da Rocha Martins J, Chacham H, de Oliveira AB, Manhabosco TM, Batista RJC. Nanoporous Graphene and H-BN from BCN Precursors: First-Principles Calculations. The Journal of Physical Chemistry C [Internet]. 2018;122 (7) :3856-3864. Publisher's Version
Fernandes TFD, Gadelha A, Barboza A, Paniago R, Campos LC, Guimaraes P, Assis P, Almeida Neves BR. Robust nanofabrication of monolayer MoS2 islands with strong photoluminescence enhancement via local anodic oxidation. 2D Materials [Internet]. 2018. Publisher's VersionAbstract
Abstract In this work, we demonstrate the nanofabrication of monolayer MoS2 islands using local anodic oxidation of few-layer and bulk MoS2 flakes. The nanofabricated islands present true monolayer Raman signal and photoluminescence intensity up to two orders of magnitude larger than that of a pristine monolayer. This technique is robust enough to result in monolayer islands without the need of meticulously fine-tuning the oxidation process, thus providing a fast and reliable way of creating monolayer regions with enhanced optical properties and with controllable size, shape, and position.