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141.
C.R. Chaves P.M.A. Farias B.S. Santos R.C. Ferreira A. Galembeck 《Applied Surface Science》2008,255(3):728-730
Semiconductor quantum dots are a promising class of materials in the labeling of biological systems. In the present study we show the marking pattern of Trypanosoma cruzi (T. cruzi) live parasites using PEGylated CdS/Cd(OH)2 fluorescent nanocrystals. The analysis obtained by confocal fluorescence microscopy and transmission electron microscopy indicates that only the endocytic paths of parasites were labeled. The parasites were alive after the incubation with the CdS/Cd(OH)2-PEG suspension. Labeling the T. cruzi with quantum dots can help to better understand the endocytosis process and also the cellular differentiation. 相似文献
142.
B.S. Santos P.M.A. Farias F.D. Menezes A.G. Brasil Jr. A. Fontes L. Romão V. Moura-Neto C.L. Cesar R. Ferreira 《Applied Surface Science》2008,255(3):790-792
Semiconductor quantum dots based on II-VI materials may be prepared to develop good biolabeling properties. In this study we present some well-succeeded results related to the preparation, functionalization and bioconjugation of CdY (Y = S, Se and Te) to biological systems (live cells and fixed tissues). These nanostructured materials were prepared using colloidal synthesis in aqueous media resulting nanoparticles with very good optical properties and an excellent resistance to photodegradation. 相似文献
143.
Jiarong Cai Wei Ma Liguang Xu Changlong Hao Maozhong Sun Xiaoling Wu Felippe Mariano Colombari Andr Farias de Moura Mariana Cristina Silva Evaldo Batista Carneiro‐Neto Ernesto Chaves Pereira Hua Kuang Chuanlai Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(48):17579-17585
The deposition of a monolayer nanoarray on the surface of a micrometer‐thick substrate is demonstrated, producing rectification characteristics at the nanoscale. The experimental results show that the heterogeneity of the structure and the charge density are the two key factors affecting rectification, which was confirmed with molecular dynamic (MD) and finite element simulations. Moreover, by altering the asymmetric electrolyte environment, the fabricated heterogeneous membrane can be used in energy conversion. This study provides insights into the mechanism underlying the generation of rectification and related factors, providing a theoretical basis for the characteristics of rectification. 相似文献
144.
Lima Handerson Rodrigues Silva Airton de Oliveira Farias Emanuel Teixeira Paulo Ronaldo Sousa Eiras Carla Nunes Lívio César Cunha 《Journal of Solid State Electrochemistry》2019,23(11):3153-3164
Journal of Solid State Electrochemistry - Methotrexate (MTX) is an antineoplastic drug widely used in cancer therapies with potentially toxic activity. This paper describes the electrochemical... 相似文献
145.
The adsorption of thiophene (C4H4S) on the clean and sulfided Mo(100) crystal surface has been studied. A fraction of the adsorbed thiophene desorbs molecularly while the remainder decomposes upon heating, evolving H2 and leaving carbon and sulfur deposits on the surface. The reversibly adsorbed thiophene exhibits three distinct desorption peaks at 360, 230–290 and 163–174 K, corresponding to binding energies of 22, 13–16 and 7–9 kcal/mol respectively. Sulfur on the Mo(100) surface preferentially blocks the highest energy binding state and causes an increase in the amount of thiophene bound in the low binding energy, multilayer state. The thiophene decomposition reactions yield H2 desorption peaks in the temperature range 300–700 K. We estimate that 50–66% of the thiophene adsorbed to the clean Mo(100) decomposes. The decomposition reaction is blocked by the presence of c(2 × 2) islands of sulfur and is blocked completely at θs = 0.5, at which point thiophene adsorption is entirely reversible. 相似文献
146.
M.H. Farias A.J. Gellman G.A. Somorjai R.R. Chianelli K.S. Liang 《Surface science》1984,140(1):181-196
The chemisorption and reactivity of O2 and H2 with the sulfided Mo(100) surface and the basal (0001) plane of MoS2 have been studied by means of Thermal Desorption Spectroscopy (TDS), Auger Electron Spectroscopy (AES) and Low Energy Electron Diffraction (LEED). These studies have been carried out at both low (10?8–10?5Torr) and high (1 atm) pressures of O2 and H2. Sulfur desorbs from Mo(100) both as an atom and as a diatomic molecule. Sulfur adsorbed on Mo(100) blocks sites of hydrogen adsorption without noticeably changing the hydrogen desorption energies. TDS of 18O coadsorbed with sulfur on the Mo(100) surface produced the desorption of SO at 1150 K, and of S, S2 and O, but not SO2. A pressure of 1 × 10?7 Torr of O2 was sufficient to remove sulfur from Mo(100) at temperatures over 1100 K. The basal plane of MoS2 was unreactive in the presence of 1 atm of O2 at temperatures of 520 K. Sputtering of the MoS2 produced a marked uptake of oxygen and the removal of sulfur under the same conditions. 相似文献
147.
148.
Dalci José Brondani Diogo Rodrigo de Magalhães Moreira Maria Patrícia A. de Farias Flávio Ricardo da S. Souza Fábio Fernandes Barbosa Ana Cristina Lima Leite 《Tetrahedron letters》2007,48(22):3919-3923
An easy to perform and regioselective synthesis of N-alkyl hydrazones/hydrazides is described, which uses an aprotic medium with kinetic control. This procedure produced the desired monoalkylated or dialkylated amines with excellent yields and selectivities. 相似文献
149.
de Farias RF de Souza JM de Melo JV Airoldi C 《Journal of colloid and interface science》2000,227(1):147-151
Polyaniline deposited on As(2)O(3) surface resulted in a new material, which was characterized by infrared spectoscopy, thermogravimetry, differential scanning calorimetry, scanning electron microscopy, X-ray diffraction, and cyclic voltammetry. The mass percentage of polymer deposited on oxide surface is approximately 13%. The scanning electron microscopy images as well as the X-ray diffraction patterns provided conclusive evidence that the oxide surface is coated by the polymer. The cyclic voltammograms of the polyaniline adsorbed on As(2)O(3) surface showed that the adsorbate exerts remarkable effects on redox processes on this oxide. The pure oxide exhibited two oxidation/reduction peaks at 0.25/-0.06 and 0.47/-0.25 V attributed tentatively to the processes As(2)O(3)(s)+6H(+)+6e(-)=2As(s)+3H(2)O and As(s)+3H(+)+3e(-)=AsH(3)(g), respectively. The polyaniline-coated sample exhibited a better-defined voltammogram in which the first oxidation peak of the oxide had its intensity increased about four times. Copyright 2000 Academic Press. 相似文献
150.
L.C. Barbosa C.K. Suzuki R.S. Katiyar C.R. Farias R. Srivastava 《Journal of Non》1986,80(1-3):657-664
We present studies related to the investigation of Brazilian natural quartz as a basic raw material for production of optical multicomponent glasses for optical fibers. The work includes characterization and selection of quartz, preparation, the melting process and glass characterization. 相似文献