Anticoagulant, Antioxidant and Antitumor Activities of Heterofucans from the Seaweed Dictyopteris delicatula

In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (～45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress.     

The Transition to Solid-State Lighting

Lighting constitutes more than 20% of total U.S. electricity consumption, a similar fraction in the European Union, and an even higher fraction in many developing countries. Because many current lighting technologies are highly inefficient, improved technologies for lighting hold great potential for energy savings and for reducing associated greenhouse gas emissions. Solid-state lighting shows great promise as a source of efficient, affordable, color-balanced white light. Indeed, assuming market discount rates, engineering-economic analysis demonstrates that white solid-state lighting already has a lower levelized annual cost (LAC) than incandescent bulbs. The LAC for white solid-state lighting will be lower than that of the most efficient fluorescent bulbs by the end of this decade. However, a large literature indicates that households do not make their decisions in terms of simple expected economic value. After a review of the technology, we compare the electricity consumption, carbon emissions, and cost-effectiveness of current lighting technologies, accounting for expected performance evolution through 2015. We then simulate the lighting electricity consumption and implicit greenhouse gases emissions for the U.S. residential and commercial sectors through 2015 under different policy scenarios: voluntary solid-state lighting adoption, implementation of lighting standards in new construction, and rebate programs or equivalent subsidies. Finally, we provide a measure of cost-effectiveness for solid-state lighting in the context of other climate change abatement policies.     

A scientific application oriented classification for metal transfer modes in GMA welding

In this work, metal transfer in solid wire GMA welding was studied. Several experiments with different combinations of gas-wire-parameters were carried out to observe metal transfer and to characterize the various transfer modes. A laser shadograph system with synchronized electrical signals and high speed filming were used. New modes were observed and their particular characteristics described for completeness. A classification for metal transfer, oriented to scientific personnel (researchers, scholars and students), is proposed, in which the modes are independent of the type of shielding gas or welding power source.     

A hybrid model for a multiproduct pipeline planning and scheduling problem

Brazilian petrobras is one of the world largest oil companies. Recurrently, it faces a very difficult planning and scheduling problem: how to operate a large pipeline network in order to adequately transport oil derivatives and biofuels from refineries to local markets. In spite of being more economical and environmentally safer, the use of a complex pipeline network poses serious operational difficulties related to resource allocation and temporal constraints. The current approaches known from the literature only consider a few types of constraints and restricted topologies, hence they are far from being applicable to real instances from petrobras. We propose a hybrid framework based on a two-phase problem decomposition strategy. A novel Constraint Programming (CP) model plays a key role in modelling operational constraints that are usually overlooked in literature, but that are essential in order to guarantee viable solutions. The full strategy was implemented and produced very adequate results when tested over large real instances.     

Validation of a UV Spectrophotometric Method for Determination of Proteolytic Activity of Enzymatic Detergents

Enzymatic detergents are widely used in health services. These products should be controlled to ensure their activity. In this paper, a UV spectrophotometric method for the determination of proteolytic activity in enzymatic detergents was validated. An artificial substrate (azocasein) was used to quantify the enzyme activity at 340 nm. The results showed that the method was satisfactory in respect to its specificity, linearity, precision, accuracy and robustness. This method fulfills both ICH’s and Brazilian criteria, demonstrating its suitability for routine analysis as well as its potential application for regulatory purposes.     

The Role of F-Box Proteins during Viral Infection

The F-box domain is a protein structural motif of about 50 amino acids that mediates protein–protein interactions. The F-box protein is one of the four components of the SCF (SKp1, Cullin, F-box protein) complex, which mediates ubiquitination of proteins targeted for degradation by the proteasome, playing an essential role in many cellular processes. Several discoveries have been made on the use of the ubiquitin–proteasome system by viruses of several families to complete their infection cycle. On the other hand, F-box proteins can be used in the defense response by the host. This review describes the role of F-box proteins and the use of the ubiquitin–proteasome system in virus–host interactions.     

Experimental behaviour of the reverse channel joint component at elevated and ambient temperatures

The reverse channel connection appears to have the best combination of desirable features under fire loading: moderate construction cost, ability to develop catenary action and extremely high ductility through deformation of the web channel (Ding and Wang, 2007). This paper presents the results of an experimental investigation of a reverse channel component conducted at the University of Coimbra as part of the European RFCS COMPFIRE Project, the main focus of which is to characterise the behaviour of steel joints that connect steel beams to concrete-filled tubular columns under natural fire loading. A series of tensile and compressive tests at ambient and elevated temperatures was conducted. The purposes of the experimental tests were to characterise the strength, stiffness and ductility of this joint component and to establish a relationship between force, displacement and temperature.     

Beliefs on vitamin and consumption of vitamin supplements among university students in the city of São Paulo

A survey was conducted in a sample of 894 students entering a private university in S?o Paulo to examine the vitamin beliefs and to verify the relation between vitamin beliefs and vitamin supplements consumption. Nineteen statements about the relation between vitamins and health were developed to assess the beliefs; the respondents answered by means of a 5-point agreement scale. Cronbach's alpha coefficient of internal consistency was determined for the total scale. 94.5% of students believe that vitamin C prevents and cures the common cold and 72.5% consider vitamins as an energy source. Many students recognize the possibility of health risks associated to excessive vitamin consumption. Vitamin supplement users had a belief score higher than non-users (p < 0.001). The results indicate that several misconceptions about vitamin benefits are common among the students and suggest a relation between vitamin beliefs and supplements consumption.     

Characterization of peptide and amino acid profile in casein hydrolysates

The nutritional quality of protein hydrolysates has been related in several reports to their di- and tripeptide contents. In the present work different hydrolytic conditions were tested using papain in order to prepare casein hydrolysates with a suitable peptide profile for being used in special diets. The hydrolysates were fractionated by size-exclusion HPLC and the rapid Correct Fraction Area method was used for quantifying the peptides. Among the five hydrolytic conditions studied, three of them gave rise to preparations having nutritionally similar peptide profiles. However, the use of the temperature of 37 degrees C and enzyme:substrate ratio (E:S) of 2% may probably be the most economical condition for industrial production.     

Structural analysis of Si-substituted hydroxyapatite: zeta potential and X-ray photoelectron spectroscopy

The aim of this study was to determine the effect of the incorporation of silicon on the surface charge of hydroxyapatite (HA) and to assess surface structural changes of HA and Si–HA induced by dissolution in both static and dynamic systems. X-ray photoelectron spectroscopy (XPS) analysis showed that SiO₄ ^4– groups were substituted for PO₄ ^3– groups in the silicon-hydroxyapatite (Si–HA) lattice according to a previously proposed substitution mechanism without the formation of other crystalline phases, such as tricalcium phosphate or calcium oxide. The substituted silicon induced a decrease in the net surface charge and the isoelectric point of HA as determined by zeta potential (ZP) measurements. At physiological pH=7.4 the surface charge of Si–HA was significantly lowered compared to unmodified HA, i.e. –50±5 to –71±5 eV, caused by the presence of silicate groups in the HA lattice, which may account for a faster in vitro apatite formation using SBF testing. XPS results indicated that silicon seems to be preferentially leached out from Si–HA surface compared to other ionic species after dissolution studies in tris-buffer using a dynamic system.