Assessing the individual microbial inhibitory capacity of different sugars against pathogens commonly found in food systems.

Highly concentrated sugar solutions are known to be effective antimicrobial agents. However, it is unknown whether this effect is solely the result of the collective osmotic effect imparted by a mixture of sugars or whether the type of carbohydrate used also has an individual chemical effect on bacterial responses, that is, inhibition/growth. In view of this, in this work, the antimicrobial properties of four sugars, namely, glucose, fructose, sucrose and maltose against three common food pathogens; Staphylococcus aureus, Escherichia coli and Salmonella enterica, were investigated using a turbidimetric approach. The results obtained indicate that the type of sugar used has a significant effect on the extent of bacterial inhibition which is not solely dependent on the water activity of the individual sugar solution. In addition, while it was shown that high sugar concentrations inhibit bacterial growth, very low concentrations show the opposite effect, that is, they stimulate bacterial growth, indicating that there is a threshold concentration upon which sugars cease to act as antimicrobial agents and become media instead. SIGNIFICANCE AND IMPACT OF THE STUDY: In this work, an analysis on the antimicrobial properties of glucose, fructose, sucrose and maltose in solution was conducted using a turbidimetric approach. Our findings indicate that while, as expected, all of these sugars exhibit significant antimicrobial effects at high concentrations, at low concentrations they appear to act as substrates for the bacteria which results in enhanced microbial growth instead of inhibition. In addition, the results obtained also suggest that the resultant osmotic stress imparted by the sugar solutions is not the only factor which determines their antimicrobial activity and that other chemical factors may be playing a significant role.

Maximizing negative thermal expansion via rigid unit modes: a geometry-based approach.

Existent rigid unit mode (RUM) models based on rotating squares, which may explain the phenomenon of negative thermal expansion (NTE), are generalized so as to assess the NTE potential for novel systems made from rectangular or rhombic rigid units. Analytical models for the area coefficients of thermal expansion (CTE) of these innovative networks are derived in an attempt to determine the optimal geometrical parameters and connectivity for maximum NTE. It was found that all systems exhibit NTE, the extent of which is determined by the shape and connectivity of the elemental rigid units (side lengths ratio or internal angle). It was also found that some of the networks proposed here should exhibit significantly superior NTE properties when compared with the well-known network of squares, and that for optimal NTE characteristics, pencil-like rigid units should be used rather than square-shaped ones, as these permit larger pore sizes that are more conducive to NTE. All this compliments earlier work on the negative Poisson's ratio (auxetic) potential of such systems and may provide a route for the design of new materials exhibiting superior thermo-mechanical characteristics including specifically tailored CTEs or giant NTE characteristics.

The Dermatology Life Quality Index 1994-2007: a comprehensive review of validation data and clinical results.

BACKGROUND: The Dermatology Life Quality Index (DLQI) is one of the most widely used dermatology-specific quality of life instruments. Over the last 5 years there has been great interest in its use. OBJECTIVES: To collect and present all information regarding the technical properties and the clinical use of the DLQI from the date it was published to the end of 2007 for use as a single source of reference. METHODS: A detailed literature search was conducted using electronic reference databases and the DLQI library in the Department of Dermatology, Cardiff University. All publications mentioning any aspect of the DLQI, from the time of its development to the end of 2007, were identified and the data concerning the DLQI in terms of its psychometric analysis, and use in clinical trials, epidemiological studies and health services research, were extracted and tabulated with all the relevant references. RESULTS: In total, 272 full articles which have included the DLQI were reviewed. Studies described in these articles were divided into five main categories: psychometric studies, descriptive/epidemiological studies, drug (topical and systemic) trials, clinical practice research, and therapeutic interventions. The DLQI has been used in 33 different skin conditions in 32 countries and is available in 55 languages. Psychometric aspects of the DLQI such as validity, reliability, responsiveness to change, factor structure, and minimal important difference were described in 115 studies. The DLQI has been used in 33 studies assessing the effectiveness of 14 different types of therapeutic interventions and in 37 studies evaluating nine types of clinical practice research. Sixty studies have used it alone or in parallel with other instruments as an outcome measure in clinical trials of 18 systemic drugs while 22 studies have used it in 14 different topical drug trials. The DLQI has also been used in 27 multinational studies. CONCLUSIONS: During the last 14 years there has been a gradual increase in the international use of the DLQI. The brevity and simplicity of use of the DLQI has resulted in its popularity both in clinical practice and in research. However, there are various issues in particular regarding its unidimensionality, differential item functioning, and minimal clinically important difference, which require further research. This article should facilitate the work of potential users of the DLQI by providing a readily available source of references for different aspects of the DLQI.

Evaluation of sympathetic vasomotor fibres in carpal tunnel syndrome using continuous wave Doppler ultrasonography.

Sympathetic vasomotor fibres carried by the median nerve and ulnar nerve innervate their respective sensory territories. The sympathetic vasomotor fibres of the median nerve were evaluated in patients with carpal tunnel syndrome and in healthy volunteers using continuous wave Doppler ultrasonography. The pulsatility index of the radialis indicis artery and the radial palmar digital artery of the little finger were measured at baseline and after stimulation. The maximal increase in the pulsatility index of each artery was measured. This was significantly lower for the radialis indicis artery in the CTS group than in the healthy controls. However, there was no significant difference in the maximal increase in pulsatility index of the radial palmar digital artery of the little finger between both groups. Sympathetic vasomotor fibres of the median nerve are affected in carpal tunnel syndrome. Continuous wave Doppler ultrasonography is easy to use and should be investigated further as a possible diagnostic tool for the confirmation of carpal tunnel syndrome.

Fermi surface of Bi2Sr2CaCu2O8

We study the Fermi surface of Bi2Sr2CaCu2O8 using angle resolved photoemission spectroscopy (ARPES) with a momentum resolution of approximately 0.01 of the Brillouin zone. We show that, contrary to recent suggestions, the ARPES derived Fermi surface is a large hole barrel centered at (pi,pi), independent of the incident photon energy. We caution that the photon energy and k dependence of the matrix elements, if not properly accounted for, can lead to misinterpretation of ARPES intensities.

An unusual case of flexor sheath tenosynovitis.

We report a case of a flexor sheath tenosynovitis caused by Mycobacterium marinum.