From Surfaces to Interfaces: Ambient Pressure XPS and Beyond

The rapidly increasing field of surfaces under ambient conditions of temperature, and pressure in gas and liquid environments, reflects the importance of understanding surface properties in conditions closer to practical situations. This has been enabled by the emergence in the last two decades of a number of new techniques, both spectroscopy and microscopy, that can deliver atomic scale information with the required surface/interface sensitivity. Here we present a short review of recent advances to illustrate the novel understanding derived from the use of new techniques focusing on the gas–solid interface, where two barriers have been bridged: the pressure gap, and the temperature gap. The later gap is very important when dealing with weakly bound molecules, where only by the presence of gas at a suitable pressure can a measurable coverage of adsorbed molecules be achieved. The temperature gap manifests also in the removal of kinetic barriers. Future developments to continue extending the range of pressures are also mentioned. Finally, new challenges that appear, both from X-ray and electron-induced damage to the sample, and from contamination under high pressure of desired gases, while maintaining very low pressures of undesirable ones.     

Changes in physico-chemical properties, hydroxymethylfurfural and volatile compounds during concentration of honey and sugars in Alicante and Jijona turrón

Turrón has being elaborated in a traditional way; however, manufacturers are trying to (a) change production systems from discontinuous to continuous and (b) improve quality/homogeneity of products. To get these objectives, detailed scientific information regarding each of the unit operations involved is needed. Thus, the objective of this study was to gain as much information as possible about the initial operation of “honey+sugars” concentration. During this stage, humidity was reduced from a 29 to 0.5% and water activity from 0.86 to 0.18. At the same time, the soluble solid content increased from 51 to 81 Brix. 5-Hydroxymethylfurfural increased during the heating stages and was constant during the cooling stage; however, contents were always below 40 mg kg⁻¹. Finally during this heating step, characteristic honey volatile compounds decreased their concentration, for instance acetoin, benzaldehyde, phenylacetaldehyde, and linalool oxide, while compounds arising from amino acids and sugars through Maillard and Strecker degradation reactions significantly increased, for instance furfuryl alcohol, furfural and 5-methyl furfural.     

Hepatobiliary clearance of glycocholic acid in Gilbert's disease

AIM: To research the behaviour of one biliary acid (glyco-cholic) i.v. injected in patients with Gilbert's disease and in healthy controls, so that contribute to the knowledge of the pathophysiological correlate between bilirubin and biliary acids. PATIENTS AND METHODS: We include 15 patients with Gilbert's disease and 7 healthy voluntary ones. We injected i.v. glycocholic acid and obtained the clearance curve (CG-RIA Abbot method). We evaluated the possible biostatistically significant differences between the obtained values of both groups though the non-parametric method of Mann-Whitney. RESULTS: The clearance curve of both groups had a similar profile; biostatisticaly there are not significant differences between the serum values of glyco-cholic acid in both groups. CONCLUSIONS: The clearance of the glyco-cholic acid in patients with Gilbert's disease had a similar behaviour as in healthy controls, without biostatisticaly significant differences between both groups.