Hypocrellin B, a perylenequinonoid pigment, and its complexes with lanthanide ions: optical characterization and enhancements in its photodynamic properties

Hypocrellins, perylenequinonoid pigments isolated from Hypocrella bambusae, are known photodynamic agents. They exhibit several advantages over the other photosensitizers, such as ready preparation, easy purification, low aggregation tendency, high singlet oxygen generation quantum yield and rapid metabolism in vivo. However, hypocrellins do not exhibit absorption at wavelengths longer than 600 nm, which limits their application for PDT. To solve this problem our efforts were focused towards modifying the properties of hypocrellin B. in this study, hypocrellin B complexes formed with the lanthanide ions lanthanum (La(3+)), terbium (Tb(3+)) and europium (Eu(3+)), using ethanol as solvent, had their optical properties characterized through spectroscopic methods. We observed that all the lanthanide ions change the HB molecular structure, since displacements in the bands were noted in both absorption and emission spectra. Different molar ratios between the HB and the lanthanide ions were tested, and it was verified that the complexes with 1 mol of HB for 2 mol of lanthanide ions present the larger red-shift comparatively to pure HB. We also determined the dimerization constants for these complexes. Under excitation at 532 nm the singlet oxygen generation quantum yields were estimated by the emission at 1270 nm, where singlet oxygen has a well known emission peak. It can be affirmed that such complexations were responsible for an improvement in the optical properties of the HB molecule, which suggests that these complexes may find a good application at in vivo studies.IPEN CNEN SP, Ctr Laser & Aplicacoes, São Paulo, BrazilUniv Fed Sao Paulo, ICAQF, Departamento de Ciências Exatas e da Terra, Diadema, BrazilWeb of Scienc

Hair fiber characteristics and methods to evaluate hair physical and mechanical properties

The hair thread is a natural fiber formed by keratin, a protein containing high concentration of sulfur coming from the amino acid cystine. The main physical proprieties of the hair depend mostly on its geometry; the physical and mechanical properties of hair involve characteristics to improve: elasticity, smoothness, volume, shine, and softness due to both the significant adherence of the cuticle scales and the movement control (malleability), as well as the easiness of combing, since they reduce the fibers static electricity. The evaluation of these effects on hair may be carried out by several methods, as: optical and electron microscopy, mechanical resistance measuring, shine evaluation and optical coherence tomography (OCT).O cabelo é uma fibra natural formada por queratina, uma proteína composta por teor elevado de enxofre proveniente da cistina. As propriedades principais do cabelo dependem de sua geometria, estrutura física. Características físicas e mecânicas das fibras capilares envolvem propriedades que melhoram: elasticidade, maciez, volume, maleabilidade, facilidade para o ato de pentear e brilho. A avaliação de tais propriedades do cabelo pode ser obtida por métodos diversos, como: microscopia óptica e eletrônica, mensuração da resistência mecânica, determinação do brilho e tomografia por coerência óptica (OCT).(CNPq) National Council for Scientific and Technological DevelopmentCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)FAPES

Hair fiber characteristics and methods to evaluate hair physical and mechanical properties

The hair thread is a natural fiber formed by keratin, a protein containing high concentration of sulfur coming from the amino acid cystine. The main physical proprieties of the hair depend mostly on its geometry; the physical and mechanical properties of hair involve characteristics to improve: elasticity, smoothness, volume, shine, and softness due to both the significant adherence of the cuticle scales and the movement control (malleability), as well as the easiness of combing, since they reduce the fibers static electricity. The evaluation of these effects on hair may be carried out by several methods, as: optical and electron microscopy, mechanical resistance measuring, shine evaluation and optical coherence tomography (OCT).O cabelo é uma fibra natural formada por queratina, uma proteína composta por teor elevado de enxofre proveniente da cistina. As propriedades principais do cabelo dependem de sua geometria, estrutura física. Características físicas e mecânicas das fibras capilares envolvem propriedades que melhoram: elasticidade, maciez, volume, maleabilidade, facilidade para o ato de pentear e brilho. A avaliação de tais propriedades do cabelo pode ser obtida por métodos diversos, como: microscopia óptica e eletrônica, mensuração da resistência mecânica, determinação do brilho e tomografia por coerência óptica (OCT)

Perdas na colheita mecanizada direta do feijoeiro comum / Losses on the mechanized direct harvest of common bean

O feijoeiro é uma cultura de grande importância para a sociedade brasileira. Dentre as etapas de produção, a colheita é uma das mais importantes. Objetivou-se com esse trabalho avaliar as perdas na colheita mecanizada direta do feijoeiro, sob diferentes velocidades de deslocamento e regulagens da colhedora. O experimento foi realizado na Fazenda Bom Sucesso, localizada no município de São Luiz do Norte - GO, situado na região do Vale São Patrício. O delineamento experimental utilizado foi o DIC, em esquema fatorial 3x2, sendo os tratamentos compostos por três velocidades de deslocamento (3, 4 e 5 km h-1) e duas regulagens dos sistemas da colhedora, com 6 repetições por tratamento. Foram avaliadas as perdas por altura de corte (PAC), perdas na plataforma (PP), perdas internas (PI), perdas total da máquina (PTM), e perdas total colheita (PTC). Os resultados foram submetidos à análise de variância e ao controle estatístico de processo. As diferentes velocidades de colheita e regulagens avaliadas não influenciaram significativamente nas perdas, embora tenha se verificado nas cartas de controle uma alta variabilidade dos dados, principalmente para as velocidades de 4 e 5 km h-1 na regulagem 1. Os maiores níveis de perdas foram observados nos mecanismos internos da colhedora, que representaram 46 a 60% da perda total da máquina. Sob a ótica do controle estatístico de processo, a velocidade de 3 km h-1 associada a regulagem 2 proporcionou menor variabilidade dos dados

Information technology and communication and best practices in it lifecycle management

In this work, we focus on the role of Information and Communication Technologies – ICT - to create additional sources of competitive advantage that can help companies to prepare themselves for sustainable growth in the long term. First, we discuss the dynamics of ICTs and the ability to generate innovations with a direct impact on business. Then we present the need for greater balance between goals of short and long term on IT projects. In the third part, we discuss how these new technologies have helped to increase the productivity of information professionals as well as to enhance decision-making process and the satisfaction of the end customer. To conclude, it is presented the main challenges that the technology-based companies will have to face in relation to the management of the lifecycle of their technology, consolidation and simplification of their processes within their computing environments, aiming to increase productivity and develop agile environments that allow the organizations to meet the demands of managing digital information

Effects of copper vapor laser radiation on the root canal wall of human teeth: A scanning electron microscope study

Objective: The aim of this study is to analyze the effects of copper vapor laser radiation on the radicular wall of human teeth. Materials and Methods: Immediately after the crowns of 10 human uniradicular teeth were cut along the cement-enamel junction, a chemical-surgical preparation of the radicular canals was completed. Then the roots were longitudinally sectioned to allow for irradiation of the surfaces of the dentin walls of the root canals. The hemi-roots were separated into two groups: one (control) with five hemi-roots that were not irradiated, and another (experimental) with 15 hemi-roots divided into three subgroups that were submitted to the following exposure times: 0.02,0.05, and 0.1 s. A copper vapor laser (510.6 nm) with a total average power of 6.5 W in green emission, frequency of 16.000 Hz, and pulse duration of 30 ns was used. Results: The results obtained by scanning electron microscope analysis showed the appearance of a cavity in the region of laser beam impact, with melting, recrystallization, and cracking on the edges of the dentin of the cavity due to heat diffusion. Conclusions: We determined that the copper vapor laser produces significant morphologic changes in the radicular wall of human teeth when using the parameters in this study. However, further research should be done to establish parameters that are compatible with dental structure in order to eliminate thermal damages. © Mary Ann Liebert, Inc