Total phenolic and carotenoid contents in acerola genotypes harvested at three ripening stages

Acerola fruits (Malpighia emarginata D.C.) were harvested from 12 different genotypes cultivated at the Active Germplasm Bank in Federal Rural University of Pernambuco, in the northeast region of Brazil. The effects of maturity stages and weather conditions on total phenolics and carotenoids content were analysed. Mature fruits harvested in the dry season showed the highest and the lowest levels of total phenolics and carotenoids, respectively. During the maturation process, phenolics degradation and carotenoids biosyntheses were observed. Among the acerola genotypes, fruits from genotype number 05 stood out, presenting the highest phenolic and carotenoid contents.     

The predictive value of intraoperative somatosensory evoked potential monitoring: review of 244 procedures

INTRODUCTION: There is some controversy regarding the value of intraoperative neurophysiological monitoring in predicting postoperative neurological deficits. We discuss our experience with the use of intraoperative somatosensory evoked potentials (SSEPs) during surgery of cranial base tumors. METHODS: We retrospectively reviewed all of the procedures that had been performed for the resection of cranial base tumors from July 29, 1993, through March 16, 1995. One hundred ninety-three consecutive patients had undergone a total of 244 procedures. SSEP waveforms were classified as follows: Type I, no change; Type II, change that reverts to baseline; Type III, change that does not revert to baseline; and Type IV, complete flattening of the SSEP waveform without improvement. Two patients had no waveforms from the beginning of the case (Type V) and were excluded from further analysis. New immediate postoperative neurological deficits were recorded. RESULTS: There were 64 male and 129 female patients, with a mean age of 46.6 years. One hundred seventy-seven patients had Type I SSEP waveforms, 13 of whom had postoperative deficits (7%). Fifty-six patients had Type II SSEPs, and nine (16%) of them had postoperative neurological deficits. Six patients had Type III SSEPs, and three had Type IV SSEPs, all of whom (100%) had postoperative deficits. There was a correlation between SSEP type and the results of the postoperative neurological examinations. The positive predictive value is 100%, and the negative predictive value is 90%. Although a change in the waveform that did not revert to baseline (Types III and IV) always predicted a postoperative deficit, a normal waveform did not always rule out postoperative deficits. Pathological abnormality, vessel encasement, vessel narrowing, degree of cavernous sinus involvement, brain stem edema, middle fossa location, final amount of resection, age, and tumor size correlated with a high predictive value of SSEP monitoring on univariate analysis (P < 0.05). None of these variables correlated significantly on multivariate analysis (P > 0.05), although brain stem edema was close (P = 0.0571). CONCLUSION: Intraoperative SSEPs have a high positive predictive value during surgery for cranial base tumors, but they do not detect all postoperative deficits.     

Anthocyanin composition of Tempranillo, Garnacha and Cabernet Sauvignon grapes from high- and low-quality vineyards over two years

The anthocyanin composition of Tempranillo, Garnacha and Cabernet Sauvignon grapes over two vintages was studied. Samples were obtained during berry ripening from two vineyards that differed by producing fruit of high and low quality. The proportions of the individual compounds remained practically constant within a single vineyard along the sampling period, the changes in the anthocyanin composition being principally quantitative. Different multivariate statistical methods showed that the anthocyanin profile was primarily determined by variety. This genetic dependence was particularly verified when the sums of the non-acylated glucosides, the acetates and the p-coumaryl derivatives, were analysed. The mean relative content corresponding to these three anthocyanin fractions was always the same within each variety, independently either of the vineyard or the vintage year considered. Relating to the individual compounds, several permanent qualitative differences between vineyards in each variety were also found, although the difference in the total anthocyanin concentration was always much higher.     

Extending the shelf-life and proximate composition stability of ready to eat foods in vacuum or modified atmosphere packaging

The stability of the proximate composition (moisture, proteins, lipids and ash) and the microbiological state of cooked ‘ready to eat’ foods in vacuum or modified atmosphere packaging were examined and compared with conventionally packaged (in air) foods. The study was carried out for 7 and 29 days, during which time the food products were stored at 3°C. Vacuum or modified atmosphere packaging were effective for prolonging the shelf-life of the studied products up to 29 days with minimal changes in the proximate composition. Aerobic mesophilic, psychrotrophic microrganisms, and yeasts and moulds increased with time regardless of packaging type but more rapidly under conventional packaging.     

Twenty-five years of subway construction in Mexico City

Construction of Mexico City's subway system began in 1968. At that time, the nature of the Mexico City subsoil, as well as aggressive regional settlements and seismicity conditions, posed serious challenges to the project. Despite the obstacles, to date more than 150 km of subway line have been constructed. The first lines were constructed using the underground, open caisson method; later lines were built overhead, in tunnel (successfully using the NATM), and on the surface. In some cases, excavations down to more than 15 m depth were executed close to buildings of significant historical and architectural value. To accomplish this, accurate construction procedures were used to cross the existing lines without discontinuing their operation at any time. This paper summarizes these experiences and offers some reflections on the future of underground excavations in Mexico's capital city for uses such as parking lots and commercial passageways.     

Effect of Branched C8 Olefins Addition to Mexican Gasoline on Motor Vehicles Exhaust Emissions

Two groups of gasoline blends were prepared using a base-gasoline, containing 7.6% MTBE and added with either lower olefins (C₅-C₆) or butene's dimer (made up of 70% branched C₈-olefins). In each gasoline group, the olefin concentration was varied 5, 10, and 15 vol%. The dimer was produced in our pilot plant facilities from a mixture of n-butenes. An FTP-75 test procedure, performed on a 98 model year vehicle, was used to assess the effect of olefins type (C₅-C₆ or C₈) and their concentration in a gasoline blend on exhaust emissions; namely: CO, total hydrocarbons, NOx, and toxic compounds, such as aldehydes and ketones. Average CO emissions dropped 20-27%, when using 5-15 vol% C₈ olefins-gasoline, in comparison with those using C₅-C₆ olefins-gasolines. Total hydrocarbons emissions, on the other hand, remained practically unaffected either by the type of olefins or their concentrations (5-15 vol%). NOx emission factors decreased 10-14% when using the C₈ olefins-gasolines, relative to those containing lower olefins. Main toxic pollutants were formaldehyde, propanone, and acetaldehyde. In average, acetaldehyde emissions decreased 23-53% in the dimer-gasoline group, but formaldehyde emissions increased 5-39%, depending on the olefins content and in comparison with the lower olefins-gasolines.     

Professional liability

Maitre Vera Van Houtte of Coppens, Horsmans and Malherbe in Brussels presents a succinct analysis of current trends, highlighting complaints being voiced about legal theories on professional liability being extended; confirming that liability law is a cyclical phenomenon and giving additional justification for the badly needed return in the constructional professional liability field, to the orthodox principles of fault-liability. Risk management is defined by way of example.     

Effect of immediate and delayed post preparation on apical dye leakage using two different sealers

Eighty freshly extracted teeth were endodontically prepared and filled with gutta-percha and either a zinc oxide-eugenol-based sealer or AH26 to determine what effect these sealers, with widely differing properties, would have on apical microleakage after either immediate or delayed dowel space preparation. The teeth were randomly assigned to 1 of 4 groups, and the post space was made either immediately after filling or after being stored in 100% humidity for 1 wk. They were then immersed in a 2% methylene blue solution under vacuum, washed, and split longitudinally. The extent of dye penetration was read by five independent observers and the results analyzed. The only significant difference was in the delayed preparation group with zinc oxide-eugenol sealer, which showed greater leakage than the other groups.