Acute endocarditis of the native aortic valve caused by Propionibacterium acnes

Propionibacterium acnes is often considered to be a contaminant but it has also been found to be the principal pathogen in serious infections. P. acnes is a rare cause of infective endocarditis. It has been suggested that aortic root abscesses are caused by bacteria that are particularly virulent. The strongest risk factor for serious infections by this bacteria is the presence of foreign bodies. A case is presented in which endocarditis of a native aortic valve caused by P. acnes was associated with an aortic root abscess. Transesophageal echocardiography is particularly helpful in the diagnosis of this severe complication of infective endocarditis. The literature for P. acnes endocarditis is reviewed.     

Sublethal effects of an organophosphate insecticide on the European eel, Anguilla anguilla

Recent research has found that family caregivers do not discuss their caregiving in terms of tasks but instead describe their care as shaped by concerns, commitments and goals. The purpose of this paper is to challenge the ways in which nurses approach the family caregiving process and to explore possibilities for evolving nursing knowledge by questioning existing practice in the light of developing insight into the ways in which being a family caregiver is meaningful. A critique of the philosophical orientations of rationalism and empiricism provides a platform to discuss the merits of a Heideggerian phenomenological approach in assisting nurses to better understand family caring experience. Such critique serves to support the notion of displacing the traditional scientific view as the prime means of disclosing truth, acknowledging alternative ways of knowing.     

Influence of corrosion rate on the mechanical interaction of reinforcing steel,oxide and concrete

This study offers an experimental and numerical analysis of the influence of the current density on oxide formation and the resulting cracking of reinforced concrete subjected to accelerated corrosion. The specimens were idealized reinforced concrete prisms in which a calibrated steel tube replaced the standard ribbed bar reported in most published works. This allowed the evolution of the inner diameter and volume of the tube to be recorded, providing relevant information on the mechanical interactions of the steel–oxide–concrete system. In addition, the information recorded during the tests also included the evolution of the corrosion depth and width of the main crack that grew across the concrete cover. Furthermore, the crack pattern after the corrosion process was analyzed by using slices of the specimens impregnated with fluorescent resin. Experiments were conducted for several current densities. The results show that decreasing the corrosion current density results in an increase in the corrosion depth necessary for crack initiation, a smaller effective volumetric expansion and a more irregular crack pattern. When combined with finite-element simulations carried out by using a model that reproduces the expansive behavior of the oxide and the cohesive fracture of concrete, the results show that the effective expansion factor of the oxide becomes smaller as the density of current is reduced. This would suggest that the corrosion rate affects both the pressure build-up in the growing oxide layer and, closely linked to this, the diffusion of oxide within the pores and cracks in the surrounding concrete.     

Approach to the Cuban scientific activity by using publication based quantitative indicators (1985–1989)

An estimation about Cuban scientific productivity based on output indicators during the period 1985–1989 is provided. Nine international bibliographic databases and three Cuban repertories have been used. Except for journal articles, no other type of Cuban document gets worldwide recognition as they are not generally included in the international databases. The greater effort in research is made in Agriculture, Biomedicine, Chemistry and Engineering, but this last topic does not reach international visibility, since the majority of its results are published in local journals. The Cuban contribution to the mainstream of world science is increasing annually. Collaboration in high level research projects existed mainly between Cuba and either USSR, German Democratic Republic and Italy. The most productive Cuban institutions in collaborative programs are the Havana University and the Academy of Sciences.     

Water network cost optimization in a paper mill based on a new library of mathematical models

The increasing costs associated with water supply and the disposal of wastewater has stimulated industries to seek more efficient water management systems. Mathematical modelling and simulation can be a very valuable tool for the study of the multiple alternatives available whilst assessing optimum solutions for water management in industry. This study introduces a new steady state model library able to reproduce industrial water circuits. It has been implemented in a novel software framework for the representation, simulation and optimization of industrial water networks. A water circuit representing a paper mill has been modelled and simulated showing the capability to reproduce real case studies. Alternative scenarios for the water network have also been tested to assess the capability of the models to optimize water circuits minimizing total cost.     

Enzymatic synthesis of sugar esters and their potential as surface-active stabilizers of coconut milk emulsions

Sugar esters are compounds with surfactant properties (biosurfactants), i.e., capable of reducing the surface tension and promote the emulsification of immiscible liquids. On the other hand, as with all emulsions, coconut milk is not physically stable and is prone to phase separation. Therefore, the aim of this work was to evaluate the synthesis of fructose, sucrose and lactose esters from the corresponding sugars using Candida antarctica type B lipase immobilized in two different supports, namely acrylic resin and chitosan, and evaluate its application in the stabilization of coconut milk emulsions. The enzyme immobilized on chitosan showed the highest yield of lactose ester production (84.1%). Additionally, the production of fructose ester was found to be higher for the enzyme immobilized on the acrylic resin support (74.3%) as compared with the one immobilized on chitosan (70.1%). The same trend was observed for the sucrose ester, although with lower percentage yields. Sugar esters were then added to samples of fresh coconut milk and characterized according to their surface tension, emulsification index and particle size distribution. Although the microscopic analysis showed similar results for all sugar esters, results indicated lactose ester as the best biosurfactant, with a surface tension of 38.0 N/m and an emulsification index of 54.1%, when used in a ratio of 1:10 (biosurfactant:coconut milk, v/v) for 48 h experiments.     

Evaluation of table olive by‐product as a source of natural antioxidants

The main by‐product from the table olive canning industry is the stone with some residual olive flesh. The purpose of this study was to evaluate the composition – phenolic compounds (hydroxytyrosol, tyrosol and oleuropein) and tocopherol – and the antioxidant activity in different fractions (flesh, stone and seed) from the table olive by‐product and the whole by‐product. The highest amounts of phenolic compounds (1710.0 ± 33.8 mg kg^?1) as well as the highest antioxidant activity (8226.9 ± 9.9 hydroxytyrosol equivalents mg kg^?1) were obtained in the seed. The highest amounts of hydroxytyrosol (854.8 ± 66.0 mg kg^?1) and tyrosol (423.6 ± 56.9 mg kg^?1) were found in the whole by‐product from the pepper stuffed olives, while the stone without seed had the maximum oleuropein content (750.2 ± 85.3 mg kg^?1). α‐Tocopherol values were between 79.8 ± 20.8 mg kg^?1 in the seed of the olive stone and 6.2 ± 1.2 mg kg^?1 in the whole by‐product from the anchovy‐stuffed olives. In light of the results obtained, it would seem possible to use table olive by‐product as a source of natural antioxidants in foods, cosmetics or pharmaceutical products, thus contributing to diminishing the environmental impact of table olive by‐product and to its revalorisation.