Synthesis of Pseudoionones by Acid and Base Solid Catalysts

The preparation of pseudoionones by aldol condensation reaction between citral and acetone have been carried out in the presence of acid (HY and beta zeolites), an acid–base (amorphous aluminophosphate) and basic catalysts such as an aluminophosphate oxynitride, MgO and different activated hydrotalcites. The results showed that acid or acid–base catalysts were not successful for performing in one pot the preparation of ionones. MgO and calcined hydrotalcites showed excellent activity and selectivity to pseudoionones, with calcined hydrotalcite more selective than MgO. Moreover, the rate of reaction can be improved by activating the hydrotalcite through rehydration. This activation can be successfully done by simply adding the optimum amount of water to the calcined hydrotalcite before reaction. The inhibiting effect of the concentration citral on the catalytic activity of rehydrated hydrotalcites that has been reported to occur at 273 K can be avoided by working at a reaction temperature of 333 K.     

MCM-41 Heterogenized Chiral Amines as Base Catalysts for Enantioselective Michael Reaction

Cinchonidine and cinchonine have been grafted onto pure silica MCM-41. It has been shown that both supported alkaloids are active catalysts for the Michael addition of ethyl 2-oxocyclopentanecarboxylate and methyl vinyl ketone, anchored cinchonidine being more active and enantioselective than anchored cinchonine. The study of the influence of the polarity of the solvent and reaction temperature on the optical induction shows that there is not a direct correlation between solvent polarity and enantioselectivity, and the maximum optical yield was obtained between 278 and 273 K.     

Aluminophosphates Oxynitrides as Base Catalysts for the Production of Dicyanomethylene Derivative Dyes

The two-step synthesis of dicyanomethylene derivative dyes has been performed using as base catalysts MgO, calcined hydrotalcites and ALPON. These solids catalyse with good conversions and selectivities the Knoevenagel reaction step, but only ALPON catalysts are able to catalyse efficiently the two reaction steps, as well as the global reaction in a one-pot system.     

CFD model performance benchmark of fast filling simulations of hydrogen tanks with pre-cooling

High gas temperatures can be reached inside a hydrogen tank during the filling process because of the large pressure increase (up to 70–80 MPa) and because of the short time (∼3 min) of the process. High temperatures can potentially jeopardize the structural integrity of the storage system and one of the strategies to reduce the temperature increase is to pre-cool the hydrogen before injecting it into the tank. Computational Fluid Dynamics (CFD) tools have the capabilities of capturing the flow field and the temperature rise in the tank. The results of CFD simulations of fast filling with pre-cooling are shown and compared with experimental data to assess the accuracy of the CFD model.     

CFD analysis of fast filling scenarios for 70 MPa hydrogen type IV tanks

High injection pressure is combined with high refueling rate for vehicles storing pressurized gaseous hydrogen onboard. As a drawback, high temperatures are developed inside the tank, which can jeopardize the structural integrity of the storage system. Computational Fluid Dynamics (CFD) codes already proved to be a valuable tool for predicting the temperature distribution within the tank during fast refueling. Results of hydrogen fast filling CFD simulations for a type IV tank, filled to 70 MPa at different working conditions are presented as follow up of the CFD model validation performed against experimental data. Alternative rates of pressure rise, adiabatic and cold filling are investigated to evaluate the effect on maximum hydrogen temperatures inside the tank. Results confirmed that the developed CFD model could be a suitable tool for investigating fast filling scenarios when experimental data are not yet available or of difficult realization.     

Extravesical involvement in patients with bladder carcinoma in situ: biological and therapy implications

PURPOSE: The biological and therapeutic implications of extravesical involvement in patients with bladder carcinoma in situ were analyzed. MATERIALS AND METHODS: Of 138 patients with bladder carcinoma in situ 87 (63%) had extravesical involvement, including the prostate in 53, the upper urinary tract in 11 and both structures in 23 (pan-urothelial involvement). With survival free of disease as an end point, univariate and multivariate analyses were done. RESULTS: Patients with extravesical involvement had worse survival than those with bladder carcinoma in situ alone (p < 0.001). In multivariate analysis prostate involvement (p = 0.0007) and pan-urothelial involvement (p = 0.0001) were selected as significant variables. When pathological patterns were considered prostatic stromal invasion (p = 0.0002) was the only variable selected. With these data 3 patient groups with disease mortality risk were defined. CONCLUSIONS: Prostate involvement and pan-urothelial involvement behave as independent prognostic factors, with the latter probably reflecting an extremetly diffuse character of carcinoma in situ. However, the upper urinary tract had no influence on survival. In patients with upper urinary tract and/or prostatic involvement limited to the mucosa treatment can be conservative. Patients with ductal or stromal involvement should undergo radical treatment. For upper tract involvement conservative approaches may be considered if there are no radiological signs of invasion or low grade tumor.     

The MAT locus revisited within a 9.8 kb fragment of chromosome III containing BUD5 and two new open reading frames.

This paper reports the DNA sequence of a segment of 9.8 kb of the chromosome III. The sequenced DNA contains the MAT alpha locus. The new sequence of the MAT alpha locus differs from the previously reported sequence by six modifications in the W segment. We have found the same modifications in the HML locus. The corrected sequence contains, in HML, an open reading frame (ORF) of 190 codons which ends at the border between the W segment and the flanking DNA. In the MAT locus, this ORF extends in the flanking DNA up to 538 codons. This ORF corresponds to a gene independently identified as BUD5 (Chant et al., 1991). This gene presents homologies with the exchange factors SDC25 and CDC25. A large ORF of 1399 codons is found on the opposite side of MAT alpha (toward the telomere). This ORF corresponds to a new gene YCR724. Next to this gene is a small ORF, YCR725, of 127 codons. The localization of this fragment on chromosome III, originally supposed to be distal from the MAT locus based on genetic distance, illustrates variation in recombination frequency along the chromosome and suggests the existence of hot spots of recombination between MAT and the THR4 locus.     

Adrenal gland incidentaloma in the oncologic patient: is its histologic study obligatory?

We evaluated the performance of an automatic polymerase chain reaction (PCR) detection system for identification of Mycobacterium tuberculosis in respiratory specimens. Six hundred and two respiratory specimens, including 557 sputa and 45 bronchial washing samples, were analyzed using the COBAS AMPLICOR Mycobacterium tuberculosis (MTB) test. The results were compared with those obtained from acid-fast microscopy, conventional culture, and clinical history. In cases of discrepancy between the results of the COBAS AMPLICOR MTB test and culture, the medical history of the patient was reviewed, the COBAS AMPLICOR MTB test was repeated, and the gene encoding M. tuberculosis superoxide dismutase was screened using PCR (SOD-PCR). Fourteen samples were excluded because the internal control test result was negative. Of 57 specimens that were culture positive for Mycobacterium species, 40 appeared to have growth of M. tuberculosis and 21 were smear positive for acid-fast bacteria. The sensitivity, specificity, and positive and negative predictive values for the COBAS AMPLICOR MTB test evaluated at our laboratory were 85.0% (34/40), 99.3% (544/548), 89.5% (34/38), and 98.9% (544/550), respectively. Three specimens that were culture positive for M. tuberculosis but negative by COBAS AMPLICOR MTB test were positive when rechecked by both COBAS AMPLICOR MTB test and SOD-PCR. Among the four specimens with positive reactions on both COBAS AMPLICOR MTB test and SOD-PCR that were culture negative, two were from patients who had been receiving antituberculosis treatment, one was from a patient who had been treated for tuberculosis for 1 year, and the other was from a patient who died of sepsis with adult respiratory distress syndrome. In more than 70% of smear-negative and culture-positive specimens and 86.4% of smear-positive specimens, M. tuberculosis was identified by the COBAS AMPLICOR MTB test within 10 hours after receipt of the specimens. Our data show that the COBAS AMPLICOR MTB test provides rapid and accurate detection of M. tuberculosis in respiratory specimens.     

Serial renal transplant surgery: technical reflections concerning third transplants

Iodine distribution was studied in isolated porcine eyes after iontophoresis using 131I-labelled solutions and chemical methods. After a 15-min treatment with a therapeutically used iodine brine, the iodine content in the ocular tissues showed the following rank order: cornea > retina > vitreous body > anterior chamber fluid > lens. Replacement of the brine by 0.15 M NaI increased the uptake values in a different way, but the same rank order was maintained. The increase was highest in the cornea (5.6-fold) and only about 2-fold in the lens, nevertheless approaching now the level of 10(-4) M, a concentration which was regarded as being optimal for the antioxidant effect of I-. Among the other eye components, the relatively high iodine enrichment of the retina was remarkable. The data are discussed with respect to a possible protective, antioxidative and OH-scavenging efficacy of I- and to previous results in the literature concerning iodine uptake in ocular tissues.