Inhibition of the decrease of volatile esters and terpenes during storage of a white wine and a model wine medium by glutathione and N-acetylcysteine

Glutathione and N‐acetylcysteine, each at 20 mg L^?1, were tested as inhibitors of the decrease of volatile esters and terpenes during storage of Debina white wine. Moreover, the inhibition of the decrease of isoamyl acetate, ethyl hexanoate and linalool in a model wine medium by glutathione and N‐acetylcysteine, each at 0–20 mg L^?1, was also tested. Several volatiles, such as isoamyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate and linalool, decreased during wine storage. Glutathione or N‐acetylcysteine significantly restricted the decrease of these volatiles. In the model medium, each thiol inhibited the decrease of the three volatiles in a dose‐dependent manner. N‐acetylcysteine inhibited the decrease of all three volatiles at 2.5 mg L^?1 while glutathione at 2.5 or 5.0 mg L^?1. The present results indicate that glutathione and N‐acetylcysteine may be taken into account as potent inhibitors of the disappearance of aromatic esters and terpenes in wines.     

Ablation of irreversibly rejected renal allograft by embolization with absolute ethanol: a new clinical application

Surgical allograft nephrectomy has been the conventional therapy for removing failed kidney allografts when clinical manifestations of graft intolerance appear. However, removal of a transplanted kidney is an extensive surgical procedure. On the other hand, transcatheter vascular embolization (TVE) has proven useful in ablating organs and could be applied to renal transplant ablation. The aim of this study was to present the results of TVE for the treatment of graft intolerance syndrome (GIS) in failed allograft kidneys. Transcatheter vascular embolization was performed in 14 allograft recipients (33 +/- 13 years of age; 10 men and four women) affected by GIS after irreversible kidney allograft failure. Graft intolerance syndrome was diagnosed by fever (93%), hematuria (50%), graft pain (36%), flu-like symptoms (29%), and increased graft size (29%). Absolute ethanol (0.1 mL/kg body weight) was injected in the allograft artery, and in seven patients a stainless steel coil was left in the renal artery following ethanol injection. All patients showed clinical disappearance of the GIS. No major complication occurred, although a postembolization syndrome of pain, fever, hematuria, numbness, and paresthesia of the affected area appeared in 11 of the 14 patients. After 2 to 56 months of follow-up no late complications occurred, with the exception of a graft abscess formation in one patient after 6 months of embolization. Subsequent transplantectomy was uneventful. In conclusion, TVE is a safe and effective method for kidney graft ablation, and it may become an alternative treatment for GIS following irreversible rejection.     

ACT-P: A configurable theorem-prover

There has been a considerable amount of research into the provision of explicit representation of control regimes for resolution-based theorem provers. However, most of the existing systems are either not adequate or too inefficient to be of practical use. In this paper a theorem prover, ACT-P, which is adequate but retains satisfactory efficiency is presented. It does so by providing a number of user-changeable heuristics which are called at specific points during the search for a proof. The set of user-changeable heuristics was determined on the basis of a classification of the heuristics used by existing resolution-based theorem provers.     

Autominder: an intelligent cognitive orthotic system for people with memory impairment

The world’s population is aging at a phenomenal rate. Certain types of cognitive decline, in particular some forms of memory impairment, occur much more frequently in the elderly. This paper describes Autominder, a cognitive orthotic system intended to help older adults adapt to cognitive decline and continue the satisfactory performance of routine activities, thereby potentially enabling them to remain in their own homes longer. Autominder achieves this goal by providing adaptive, personalized reminders of (basic, instrumental, and extended) activities of daily living. Cognitive orthotic systems on the market today mainly provide alarms for prescribed activities at fixed times that are specified in advance. In contrast, Autominder uses a range of AI techniques to model an individual’s daily plans, observe and reason about the execution of those plans, and make decisions about whether and when it is most appropriate to issue reminders. Autominder is currently deployed on a mobile robot, and is being developed as part of the Initiative on Personal Robotic Assistants for the Elderly (the Nursebot project).     

Using a hybrid rule-based approach in developing an intelligent tutoring system with knowledge acquisition and update capabilities

In this paper, we present the architecture and describe the functionality of an Intelligent Tutoring System (ITS), which uses an expert system to make decisions during the teaching process. The expert system uses neurules for knowledge representation of the pedagogical knowledge. Neurules are a type of hybrid rules integrating symbolic rules with neurocomputing. The expert system consists of three components: the user modelling unit, the pedagogical unit and the inference system. The pedagogical knowledge is distributed in a number of neurule bases within the user modelling and the pedagogical unit. Another important component of the ITS, for both its development and maintenance, is its knowledge management unit, which provides knowledge acquisition and knowledge update capabilities to the system, that is, offers expert knowledge authoring capabilities to the system.     

Research strategies in the evaluation of depressive states

The present paper discusses the respective benefits of a latent trait model and of factorial correspondence analysis in the research strategies of depression inventory construction. Results on the processing of the same list of depressive symptoms by both analyses are presented. The fact that, in questionnaires based on latent models, each answer brings an information closely dependent on its place in the hierarchical order is underlined. The latent trait strategy construction offers an accurate way to assess how patients recover from depression.     

Thermoresponsive behaviour in aqueous solution of poly(maleic acid‐alt‐vinyl acetate) grafted with poly(N‐isopropylacrylamide)

The synthesis of a thermoresponsive graft copolymer consisting of a maleic acid/vinyl acetate alternating copolymer backbone (MAc‐alt‐VA) and poly(N‐isopropylacrylamide) (PNIPAM) side chains is reported. Turbidimetric measurements in dilute aqueous solutions showed that no macroscopic phase separation takes place when the temperature is raised above the lower critical solution temperature (LCST) of PNIPAM, even at pH = 2. Moreover, in semi‐dilute aqueous solutions, a pronounced thermally induced viscosity increase (thermothickening) was observed. This thermoresponsive behaviour has been attributed to the interconnection of the hydrophilic MAc‐alt‐VA graft copolymer backbones by means of the hydrophobic PNIPAM side chain aggregates formed as the temperature increases above the LCST of this polymer. Copyright © 2004 Society of Chemical Industry     

Solution casting versus melt compounding: effect of fabrication route on the structure and thermal behavior of poly(l-lactic acid) clay nanocomposites

Poly(l-lactic acid) (PLLA) nanocomposites containing various loadings of organo-modified montmorillonite were prepared via twin screw extrusion and solution casting in order to investigate the effect of processing route on the structure and the thermal properties of the fabricated nanohybrid materials. X-ray diffraction (XRD) testing indicated that a better dispersion of the modified inorganic filler can be achieved by solution intercalation. The interlayer distance of the mineral, and thus the type and structure of the nanohybrid formed, was found to be affected by the polymer content only in the case of the nanocomposites produced by the solution casting method. Thermogravimetric analysis (TGA) revealed that the hybrids prepared by melt compounding displayed increased thermal stability. Differential scanning calorimetry (DSC) showed that the fabrication route influences the crystallization process of the polymer.