The usefulness of the timeliness of endoscopic sphincterotomy in severe acute pancreatitis of biliary origin

There are evidence indicating that endoscopic retrograde cholangiopancreatography with sphincterotomy (ERCP+S) reduces the rate of complications in patients with severe acute biliary pancreatitis (ABP). The aim of this study was to analyze our experience in the treatment of severe ABP with ERCP+S and compare the evolution of the patients treated early (3 days or less following admission) with those treated late (after the 3rd day). A retrospective review of the clinical histories of the 16 patients with severe ABP treated with ERCP+S over the last two years is presented, analyzing their clinical features on admission and evolution. Biliary stones or biliary sludge was observed in 11 cases (69%). Nine patients had undergone early, and 7 late, ERCP+S. The patients of the latter group presented a greater number of complications during evolution than the former group (43% vs 0%; p = 0.025). The mortality of the patients of the late ERCP+S was also greater although without statistical significance (28.6% vs 0%; p = 0.15). No complication secondary to ERCP+S was detected. These findings confirm the fact that ERCP+S performed early in severe ABP significantly reduces the number of complications and is associated with a lower mortality.     

Prevalence of hepatitis A antibodies in southeastern Spain: a population-based study

OBJECTIVES: To identify variables, other than legal definitions, that may have influenced North Cheshire's Coroner in returning a verdict of 'suicide' or an 'open verdict' on unexpected deaths of the elderly. DESIGN: Retrospective review of all coroner's verdicts in North Cheshire during a 5-year period 1989-1993. MATERIAL: Forty-seven 'suicide' and 'open verdict' deaths in North Cheshire between 1989 and 1993 as defined in ICD classification 'E' codes E950-E959 and E980-E989, respectively, that were returned on the deceased aged 65 and above who died within North Cheshire. FINDINGS: Logistic regression analysis suggests that the Coroner's decision may be influenced by: intimation of intent, psychiatric history and method of death. Sex of the deceased, history of attempted suicide, social setting and history of alcohol problems did not appear significantly associated with coroner's verdict.     

Effect of processing temperature on the bitumen/MDI-PEG reactivity

Reactive polymers are lately gaining acceptance to give added value to a residue of the crude oil refining process such as bitumen. The resulting material should display enhanced mechanical properties to be considered for advanced applications in construction. In the present paper, we report the effect of processing temperature on the reaction between bitumen compounds and an isocyanate-based reactive polymer, synthesized by reaction of polymeric MDI (4,4′-diphenylmethane diisocyanate) with a low molecular weight polyethylene-glycol (PEG). Rheokinetics experiments, viscosity measurements at 60 °C, atomic force microscopy (AFM) characterization, thin layer chromatography (TLC-FID) analysis and thermogravimetric studies (TGA) were performed on the reactive polymer and on samples of MDI-PEG modified bitumen containing 2 wt.% of the polymer. Results showed the existence of an optimum processing temperature arisen as a consequence of opposite effects: microstructural availability for the formation of a polymer–bitumen network, reaction ability and polymer thermal degradation. Consequently, this study aims to serve as a guideline for the refining and asphalt industries facing the stage of selecting the optimum processing parameters.     

Silica–alumina-supported transition metal sulphide catalysts for deep hydrodesulphurization

Deep hydrodesulphurization (HDS) of dibenzothiophene (DBT) and gas-oil has been carried out on amorphous-silica–alumina (ASA)-supported transition metal sulphides (TMS) under conditions which approach industrial practice. The activity and selectivity of the binary Ni-, Ru- and Pd-promoted Mo catalysts were compared with the monometallic ones (Ru, Ir, Pd, Ni, Mo on ASA). For both HDS of DBT and gas-oil, the observed activity trends were similar; thus, all catalysts were more active with model feed than with gas-oil, and less active than commercial CoMo/Al₂O₃. The binary catalysts showed larger activity than monometallic ones, with Ni–Mo catalyst being more effective than Ru–Mo or Pd–Mo. For Ni–Mo sample, the X-ray photoelectron and temperature-programmed reduction techniques confirmed that incorporation of Mo minimises metal–support interaction, although the formation of nickel hydrosilicate was not prevented. The consecutive impregnation of calcined Mo/ASA catalyst with precursor solution followed by calcination enhances molybdenum surface exposure in binary samples. As a consequence, the temperature of reduction of MoO₃ to molybdenum suboxides is decreased.     

A Nondestructive Methodology for the Study of Colored Enamels: Insights into Manufacturing and Weathering Processes

We studied ancient enamels on gilded copper from a collection of archeological horse harness pendants of the Museo Instituto Valencia de Don Juan (Madrid, Spain) to test the benefits of a new, nondestructive analytical methodology based on chemometric analysis (i.e., Principal Component Analysis, PCA) on micro‐ATR‐FTIR spectral data and chemical quantification using SEM‐EDS. The novelty of this approach was threefold: (i) PCA allowed the discrimination of the different harness pendants of known origin and attributed to the 14th and 15th centuries according to the chemical complex composition, nanostructure, glass weathering, and/or coloring mechanisms of each colored enamel, separately (i.e., red, purple, blue, and white), (ii) it is a cheap, easily available and nondestructive methodology that enables us to (iii) draw archeological conclusions about the quality of the manufacturing process, reassess the chronology of these objects and attempt to attribute them to different workshops according to the different traditional recipes identified. In particular, the enamels were made of alkali and/or alkaline earth lead‐glass with a wide range of chemical compounds in the form of pigments or opacifiers. Two types of coloring mechanisms were identified, colloidal particles such as copper‐ruby for red enamels, and ionic mechanisms such as Fe(II) and Co(II) to achieve a blue pigments; Mn(III) in the purple pigment; and two kind of white enamels were identified, i.e., tin oxide as an opacifier and uranium oxide. In addition, we established the reason for the poor state of conservation of some of the enamels by means of the identification of depolymerization and ion exchanges, well‐known harmful effects of glass weathering, and finally a chronology was assigned for some of these pieces according to the enamel composition.     

Does the Neuroprotective Role of Anandamide Display Diurnal Variations?

The endocannabinoid system is a component of the neuroprotective mechanisms that an organism displays after traumatic brain injury (TBI). A diurnal variation in several components of this system has been reported. This variation may influence the recovery and survival rate after TBI. We have previously reported that the recovery and survival rate of rats is higher if TBI occurs at 1:00 than at 13:00. This could be explained by a diurnal variation of the endocannabinoid system. Here, we describe the effects of anandamide administration in rats prior to the induction of TBI at two different times of the day: 1:00 and 13:00. We found that anandamide reduced the neurological damage at both times. Nevertheless, its effects on bleeding, survival, food intake, and body weight were dependent on the time of TBI. In addition, we analyzed the diurnal variation of the expression of the cannabinoid receptors CB1R and CB2R in the cerebral cortex of both control rats and rats subjected to TBI. We found that CB1R protein was expressed more during the day, whereas its mRNA level was higher during the night. We did not find a diurnal variation for the CB2R. In addition, we also found that TBI increased CB1R and CB2R in the contralateral hemisphere and disrupted the CB1R diurnal cycle.     

Effect of low‐temperature plasma and chitosan treatment on wool dyeing with Acid Red 27

This study examines in detail the influence of low‐temperature plasma and biopolymer chitosan treatments on wool dyeability. Wool knitted fabrics were treated and characterized by whiteness and shrink‐resistance measurements. Surface modification was assessed by contact‐angle measurements of human hair fibers, which were used as a model to study the wetting properties of the treated wool knitted fabrics. The dyeing behavior was assessed from the diffusion mechanism point of view. The dyeing kinetics were measured at two different pHs (4.2 and 6.5) and three different temperatures (60, 85, and 100°C) to gain information about the contribution of the surface modification treatment to the dyeing mechanism. The exhaustion and reflectance data were compared, and the apparent diffusion coefficients were calculated. On the basis of the obtained results, a model for the dyeing mechanism of the chitosan treated wool was proposed. When treated with chitosan, the polymer sheath spread on the surface of the fibers acted as a predominant dyeing site in very short dyeing times, thus interacting with the dye and in later stages imparting the dye to the wool fiber. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2204–2214, 2005     

Electrochemical impedance spectroscopy study of a surface confined redox reaction: The reduction of azobenzene on mercury in the absence of diffusion

The kinetics of azobenzene reduction on mercury electrodes in the absence of diffussional mass transport is studied by electrochemical impedance spectroscopy (EIS) in acetic acid/acetate buffered solutions at different pH values. Cyclic voltammetry experiments confirm the absence of diffusion effects and provide the values of the surface equilibrium potential. The analysis of the impedance frequency spectrums at every potential within the faradaic region conforms well the model and provides the global rate constant of the process, k_f. The potential dependence of k_f suggests the existence of an EE mechanism, with two electron transfers controlling the overall rate. The kinetic parameters of every step are obtained and their pH dependences clarify the role played by the protonation steps.     

Bitumen chemical modification by thiourea dioxide

This work evaluates a novel bitumen modification through the use of a chemical agent, thiourea dioxide, substance which has been traditionally used as a reducing agent. Thermo-gravimetric analysis demonstrated the formation of new chemical compounds, most probably originated through reactions between products from thiourea dioxide thermal decomposition and some highly polar bitumen molecules. As a result of these reactions, which continues even after 60 days, bitumen permanent deformation resistance at high temperature is enhanced, as indicated by a significant increase in its viscosity and elastic features. On the other hand, thiourea dioxide addition produces changes in the bitumen colloidal nature, which improve its flexibility at low in-service temperatures, and consequently its resistance to thermal cracking under loading. In fact, dynamic bending tests indicated a remarkable decrease in the value of binder glass transition temperature, which was further corroborated by differential scanning calorimetry. As a conclusion, thiourea dioxide can be seen as a promising modifying agent, which can extend the in-service temperature range at which bitumen would present a satisfactory performance.     

Morphological and mechanical properties of polypropylene [PP]/poly(ethylene vinyl acetate) [EVA] blends. II: Polypropylene‐(ethylene‐propylene) heterophasic copolymer [PP‐EP]/EVA systems

Morphological characteristics and mechanical properties of PP‐EP/EVA blends were studied and compared to those of PP/EVA previously reported. For the PPEP/EVA blends, interfacial interactions in amorphous zones, which were associated with shifts in T_g, were well defined compared to those of PP/EVA blends, although the nature of crystalline zones was similar for both systems. At EVA concentrations up to 20%, the elongation at break and impact strength slightly increased in both systems. However, PP‐EP/EVA displayed higher values of these properties compared with PP/EVA. At high EVA concentrations (above 20%), the indicated properties were enhanced in both polymeric systems, and the same proportional behavior was maintained. The decrease in tensile strength of PP‐EP/EVA was not as marked as in PP/EVA with the addition of EVA, and it remained below PP/EVA at high EVA concentrations. The improvement in properties of PP‐EP/EVA was attributed to favorable interactions between the ethylene groups contained in both copolymers. These interactions rendered a high degree of compatibility between the PP‐EP and EVA components.