Design em sites de encontro: promessas de amor verdadeiro, rápido, anônimo e gratuito

O presente ensaio parte de pesquisa em desenvolvimento sobre a atração amorosa na Internet. Os sites de namoro são considerados lugar de encontro na rede, oferecendo aos seus usuários inúmeros recursos interativos para facilitar o conhecimento de possíveis parceiros amorosos. Aponta aspectos relacionados às estratégias utilizadas pelos sites para atrair pessoas. O design das páginas principais e anúncios são fonte de rico material de análise, reforçando mensagens atrativas que podem contribuir para o sucesso destes sites junto à sua clientela.

Comparison among different pH values of Rhodamine B solution impregnated into mesoporous silica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of silica surface on luminescence properties of tb3+-glutamic acid.

We studied the effect of silica surface on luminescence properties of terbium complex by spectroscopy characterization, where microparticles of mesoporous silica type MSU-X was prepared. We used silica with different surface: calcined, washed, functionalized with 3- aminopropyl-triethoxysilane (APTES), and 3-glycidoxypropyl-trimethoxysilane (GPTMS); impregnated with Tb3+-glutamic acid complex. The obtained materials were characterized by scanning electron microscopy, porosity measurements, small-angle X-ray scattering, as structural characterization; Fourier transform infrared and luminescence spectroscopy, as spectroscopy characterization. Finally, we observed that functional groups at the silica surface lead to changes on luminescent properties of the final materials. The observed shift of the absorption and emission bands can be assigned to the effect of the functional groups of mesoporous silica.

Rap florido: reconhecimento artístico, amor e relações de gênero

Pós-graduação em Ciências Sociais - FFC

Autismo: aspectos cognitivos, educacionais e neurobiológicos com base na análise dos livros Mundo singular: entenda o autismo e o Os gatos nunca mentem sobre o amor e na literatura especializada

The autism is a severe mental illness that involves psychological, social, educational and neurobiological aspects. The Education plays an important role in recovering, preserving and increasing the cognitive task of people with autism. There are several ways to observe a person with autism. Through the studying of cases, it is also possible to address issues of everyday life of the person with the illness, its cognitive issues and its obstacles of psychosocial involvement, as well as psychological aspects such as illness acknowledgement. Through specialized literature, it is possible to identify characteristics referring to the learning process and neurobiological components involved in the condition, such as brain activity disorder and genetic factors. The objectives of this paper are: from the analysis of two books: Unique World: comprehend the Autism (SILVA, A. B. B; GAIATO, M.B; REVELES, L.T) and The cats never lie about love (DILLON, J.), it is intended to describe cognitive and psychosocial aspects of the autism. Based on the specialized literature, the goal is to identify cognitive and neurobiological components in the illness. The methods that were used: analysis of the books Unique World: comprehend the Autism and The cats never lie about love to describe psychosocial and educational aspects of the autism; analysis of the specialized literature to identify clinical and neurobiological components of the illness, such as changes in brain activity, genetic factors or clinical evolution; and also details of the Education role in preserving the person with autism and his cognitive and emotional development. The study had the documentary research as reference for the methodological design, including book analysis and research in specialized literature. It is intended to deepen discussions about the Education roles related to the cognitive and neurobiological aspects of the autism

Aspectos do amor no Roman de la Rose de Guillaume de Lorris e Jean de Meun (Século XIII)

Pós-graduação em História - FCLAS

Preparação e caracterização de híbridos orgânico-inorgânicos à base de epoxí-silica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Preparação e caracterização de híbridos orgânico-inorgânicos à base de epoxí-silica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Dually fluorescent silica nanoparticles

The cationic dyes 9-aminoacridine (9AA) and safranine (Sf) were entrapped into silica spheres of about 0.2 mu m diameter prepared by modified Stober method. The fluorescent materials are investigated by steady-state and time-resolved emission, in addition of confocal fluorescence microscopy. Silica particles containing 9-aminoacridine (SP9AA) and safranine (SPSf or both dyes (SPSf9AA) are emissive particles. When both dyes are present in the same particle but loaded in sequential stages 9AA emission is quenched as a consequence of energy transfer from 9AA (donor) to Sf (acceptor). This result suggests that particle growing processes where the acceptor is incorporated first into the core do not prevent donor/acceptor pairs to be close due to an overlay of the concentration gradients of both dyes in a radial core-shell like distribution. (C) 2010 Elsevier B.V. All rights reserved.

Shape Changes of Pt Nanoparticles Induced by Deposition on Mesoporous Silica

Polyvinylpyrollidone (PVP)-capped platinum nanoparticles (NPs) are found to change shape from spherical to flat when deposited on mesoporous silica substrates (SBA-15). Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and extended X-ray absorption fine structure (EXAFS) analyses are used in these studies. The SAXS results indicate that, after deposition, the 2 nm NPs have an average gyration radius 22% larger than in solution, while the EXAFS measurements indicate a decrease in first neighbor co-ordination number from 9.3 to 7.4. The deformation of these small capped NPs is attributed to interactions with the surface of the SBA-15 support, as evidenced by X-ray absorption near-edge structure (XANES).

Immobilization of marine fungi on silica gel, silica xerogel and chitosan for biocatalytic reduction of ketones

The scanning electron microscopy (SEM) analysis showed that whole living hyphal of marine fungi Aspergillus sclerotiorum CBMAI 849 and Penicillium citrinum CBMAI 1186 were immobilized on support matrices of silica gel, silica xerogel and/or chitosan. P. citrinum immobilized on chitosan catalyzed the quantitative reduction of 1-(4-methoxyphenyl)-ethanone (1) to the enantiomer (S)-1-(4-methoxyphenyl)-ethanol (3b), with excellent enantioselectivity (ee > 99%, yield = 95%). Interestingly, ketone 1 was reduced with moderate selectivity and conversion to alcohol 3b (ee = 69%, c 40%) by the free mycelium of P. citrinum. This free mycelium of P. citrinum catalyzed the production of the (R)-alcohol 3a, the antipode of the alcohol produced by the immobilized cells. P. citrinum immobilized on chitosan also catalyzed the bioreduction of 2-chloro-1-phenylethanone (2) to 2-chloro-1-phenylethanol (4a,b), but in this case without optical selectivity. These results showed that biocatalytic reduction of ketones by immobilization hyphal of marine fungi depends on the xenobiotic substrate and the support matrix used. (c) 2012 Elsevier B.V. All rights reserved.

Structural and Luminescence Properties of Silica-Based Hybrids Containing New Silylated-Diketonato Europium(III) Complex

A new betadiketonate ligand displaying a trimethoxysilyl group as grafting function and a diketone moiety as complexing site (TTA-Si = 4,4,4-trifluoro-2-(3-trimethoxysilyl)propyl)-1-3-butanedione (C4H3S)COCH[(CH2)(3)Si(OCH3)(3)]COCF3) and its highly luminescent europium(III) complex [Eu(TTA-Si)(3)] have been synthesized and fully characterized. Luminescent silica-based hybrids have been prepared as well with this new complex grafted on the surface of dense silica nanoparticles (28 +/- 3 nm) or on mesoporous silica particles. The covalent bonding of Eu(TTA-Si)(3) inside the core of uniform silica nanoparticles (40 +/- 5 nm) was also achieved. Luminescence properties are discussed in relation to the europium chemical environment involved in each of the three hybrids. The general methodology proposed allowed high grafting ratios and overcame chelate release and tendency to agglomeration, and it could be applied to any silica matrix (in the core or at the surface, nanosized or not, dense or mesoporous) and therefore numerous applications such as luminescent markers and luminophors could be foreseen.

Enzymatic Solid-Phase Reactor Based on Silica Organofunctionalized with p-Phenylenediamine for Electrochemical Detection of Phenolic Compounds

A new biomaterial, based on silica organofunctionalized with p-phenylenediamine (p-PDA) and the enzyme peroxidase, was used in the development of an enzymatic solid-phase reactor. The analytical techniques used in the characterization showed that the organic ligand was incorporated into the silica matrix. Thus, the silica modified with p-PDA allowed the incorporation of peroxidase by the electrostatic interaction between the carboxylic groups present in the enzyme molecules and the amino groups attached to the silica. The enzymatic solid-phase reactor was used for chemical oxidation of phenols in 1, 4-benzoquinone that was then detected by chronoamperometry. The system allowed the analysis of hydroquinone with a detection limit of 83.6 nmol L-1. Thus, the new material has potential in the determination of phenolic compounds river water samples.

Broad combined orange-red emissions from Eu2+- and Eu3+-doped low-silica calcium aluminosilicate glass

In this paper, a broad combined orange-red emission from Eu2+- and Eu3+-doped low-silica calcium aluminosilicate (LSCAS) glass is reported. Spectroscopic results demonstrate that it is possible to tune the emission wavelength by changing the excitation wavelength in the UV-Vis region. The color coordinates for the emission spectra were calculated, and using the Commission Internationale de l'Eclairage 1931 and 1976 chromatic diagrams, it is possible to note that they are dependent on the excitation wavelength. In addition, the (u', v') color coordinates for the investigated LSCAS samples are close to the Planckian spectrum in the cold region between 2000 and 2600K. Our results show that the Eu:LSCAS system can be used in a white light phosphor when mixed in aggregate with phosphors using green-yellow luminescent ions. (c) 2012 Optical Society of America

Self-Assembly of Poly(4-vynil-N-alkylpyridinium) Bromide onto Silica: Effect of Side-Chain Length on Structural Aspects at a Molecular Level

Self-assembly of poly(4-vynil-N-alkyl)pyridinium bromide with alkyl side chains of 2, 5, 7, 10, or 16 carbons from ethanolic solutions onto flat silica surfaces was studied by means of ellipsometry, atomic force microscopy (AFM), contact angle measurements, and sum-frequency generation (SFG) vibrational spectroscopy in the CH3 and CH2 stretch region. Ab initio quantum-chemical calculations on the N-alkylpyridinium side-group with restricted Hartree-Fock (RHF) method and 6-311G (d,p) basis set were C one to estimate the charge distribution along the pyridinium ring and the alkyl side-chain. SFG results showed that longer side chains promote the disorientation of the alkyl groups at the surface, corroborating with the contact angle values. AFM images revealed film homogeneity, regardless the alkyl side group. However, after 24 h contact with water, ringlike structures appeared on the film surfaces, when the polycation alkyl side chain had 7 or less carbons, and as the alkyl chain increased to 10 or 16 carbons, the films dewetted because the hydrophobic interactions prevailed over the electrostatic interactions between the pyridinium charged groups and the negatively charged SiO2 surface. Under acid conditions (HCl 0.1 mol.L-1), the film mean thickness values decreased up to 50% of original values when the alkyl side chains were ethyl or pentyl groups due to ion-pair disruption, but for longer groups they remained unchanged. Quantum-chemical optimization and Mulliken electron population showed that (i) from C2 to C15 the positive charge at the headgroup (HG) decreased 0.025, while the charge at combined HG + alpha-CH2 increased 0.037; and (ii) for C6 or longer, the alkyl side group presents a tilt in the geometry, moving away from the plane. Such effects summed up over the whole polymer chain give support to suggest that when the side chains are longer than 7 carbons, the hydrophobic interaction decreases film stability and increases acid resistance.