Water, water everywhere but not a drop to drink?

Biofilms are emerging as an increasing problem as medical technology advances. Dental practice is no exception and interest in the role of biofilms within dental units as a possible source of cross-infection is intensifying. It is difficult to quantitate the risks associated with aerosolised bacteria for the majority of patients seen in general practice. However, it seems prudent to eliminate this source of infection during treatment of compromised patients. This article attempts to provide a brief overview of current concepts and problems in this area of infection control

Patient safety in Europe: medication errors and hospital-acquired infections

The Report was commissioned by the European Federation of Nurses Associations (EFN) in November 2007 in order to support its policy statements on Patient Safety (June 2004). In that statement the EFN declares its belief that European Union health services should operate within a culture of safety that is based on working towards an open culture and the immediate reporting of mistakes; exchanging best practice and research; and lobbying for the systematic collection of information and dissemination of research findings. This Report adressess specifically the culture of highly reliable organisations using the work of James Reason (2000). Medication errors and hospital-acquired infections are examined in line with the Reprt´s parameters and a range of European studies are used as evidence. An extensive reference list is provided that allows EFN to explore work in greater detail as required

The Hubbard Dimer: A density functional case study of a many-body problem

This review explains the relationship between density functional theory and strongly correlated models using the simplest possible example, the two-site Hubbard model. The relationship to traditional quantum chemistry is included. Even in this elementary example, where the exact ground-state energy and site occupations can be found analytically, there is much to be explained in terms of the underlying logic and aims of Density Functional Theory. Although the usual solution is analytic, the density functional is given only implicitly. We overcome this difficulty using the Levy-Lieb construction to create a parametrization of the exact function with negligible errors. The symmetric case is most commonly studied, but we find a rich variation in behavior by including asymmetry, as strong correlation physics vies with charge-transfer effects. We explore the behavior of the gap and the many-body Green's function, demonstrating the `failure' of the Kohn-Sham method to reproduce the fundamental gap. We perform benchmark calculations of the occupation and components of the KS potentials, the correlation kinetic energies, and the adiabatic connection. We test several approximate functionals (restricted and unrestricted Hartree-Fock and Bethe Ansatz Local Density Approximation) to show their successes and limitations. We also discuss and illustrate the concept of the derivative discontinuity. Useful appendices include analytic expressions for Density Functional energy components, several limits of the exact functional (weak- and strong-coupling, symmetric and asymmetric), the Kohn-Sham hopping energy functional for 3 sites, various adiabatic connection results, proofs of exact conditions for this model, and the origin of the Hubbard model from a minimal basis model for stretched H$_2$

Optimum hybrid vehicle configurations for heavy duty applications

Increased concern about the fuel economy of and emissions from automobiles has led to interest in the use of hybrid electric powertrains and the introduction of several production vehicles in both heavy-duty and light-duty applications. Hybrid electric vehicles (HEVs) use a combination of electric motor(s) and another power source such as an internal combustion engine (ICE) or fuel cell. While these vehicles show great potential for use in a wide variety of driving situations, the optimization of components and control strategies is quite complex.;In this thesis, Class 2B, Class 6, and Class 8 vehicles are determined by averaging a variety of actual vehicles from each class and are simulated in Microsoft Excel over a variety of driving cycles to attempt to optimize their design and control. The drive cycles are modified to represent realistic expectations of the dynamic performance of vehicles from each class. Two types of hybrid powertrains are simulated. The series HEV is propelled solely by electric motors with energy coming from batteries and an alternator driven by an ICE. The parallel HEV is propelled by both electric motors and an ICE with charging-while-driving capabilities. The model is based on power requirements for each vehicle class and addresses concerns such as engine, battery, and driveline efficiencies. The control strategy forces the engine to run at a fixed percentage of the power required at the wheels plus or minus a battery state of charge correction factor.;Fuel economy increases of 100 to 150 percent were seen for Class 6 and 8 vehicles on transient cycles while 10 to 20 percent increases were seen on more constant speed cycles. The Yard cycle, a low average demand, highly transient cycle, was shown to be particularly suited to HEVs

A recommended numbering scheme for influenza A HA subtypes.

Comparisons of residues between sub-types of influenza virus is increasingly used to assess the zoonotic potential of a circulating strain and for comparative studies across subtypes. An analysis of N-terminal cleavage sites for thirteen subtypes of influenza A hemagglutinin (HA) sequences, has previously been described by Nobusawa and colleagues. We have expanded this analysis for the eighteen known subtypes of influenza. Due to differences in the length of HA, we have included strains from multiple clades of H1 and H5, as well as strains of H5 and H7 subtypes with both high and low pathogenicity. Analysis of known structures of influenza A HA enables us to define amino acids which are structurally and functionally equivalent across all HA subtypes using a numbering system based on the mature HA sequence. We provide a list of equivalences for amino acids which are known to affect the phenotype of the virus.Funding provided by (DJS) Bill & Melinda Gates Foundation Global Health (http://www.gatesfoundation.org/) Grant # OPPGH5383, (DJS) European Union FP7 program ANTIGONE (http://cordis.europa.eu/programme/rcn/852_en.html) (278976) and (DJS) National Institute of Allergy and Infectious disease (http://www.niaid.nih.gov) Contract HHSN266200700010C. The funders had no role in the study design, data collection, analysis, decision to publish or preparation of the manuscript.This is the final published version. It originally appeared at http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0112302

Monomerization of Cytosolic Mature Smac Attenuates Interaction with IAPs and Potentiation of Caspase Activation

The four residues at the amino-terminus of mature Smac/DIABLO are an IAP binding motif (IBM). Upon exit from mitochondria, mature Smac interacts with inhibitor of apoptosis proteins (IAPs), abrogating caspase inhibition. We used the ubiquitin fusion model to express mature Smac in the cytosol. Transiently expressed mature Smac56-239 (called Smac56) and Smac60-239 (called Smac60), which lacks the IBM, interacted with X-linked inhibitor of apoptosis protein (XIAP). However, stable expression produced wild type Smac56 that failed to homodimerize, interact with XIAP, and potentiate caspase activation. Cytosolic Smac60 retained these functions. Cytosolic Smac56 apparently becomes posttranslationally modified at the dimer interface region, which obliterated the epitope for a monoclonal antibody. Cytosolic Smacδ, which has the IBM but lacks amino acids 62–105, homodimerized and weakly interacted with XIAP, but failed to potentiate apoptosis. These findings suggest that the IBM of Smac is a recognition point for a posttranslational modification(s) that blocks homodimerization and IAP interaction, and that amino acids 62–105 are required for the proapoptotic function of Smac