Autohydrolysis and organosolv process for recovery of hemicelluloses, phenolic compounds and lignin from grape stalks.

A combination of two environment-friend processes for hemicelluloses and lignin recovery from red grape stalks were investigated: an autohydrolysis pretreatment at 180°C for 30 min followed by a non-catalysed ethanol organosolv step at 180°C for 90 min. Hemicelluloses were precipitated by ethanol addition to autohydrolysis liquor, while lignin was tentatively precipitated by acidification of liquors from both the processes. Results suggest that stalks hemicelluloses can be easily hydrolysed requiring a milder treatment to reduce sugar degradation, while the organosolv process did not give a consistent delignification. Autohydrolysis allowed a recovery of 2% (on stalks d.m.) of total phenols in the liquor. Organosolv liquor had a higher concentration of phenols (corresponding to 0.72% of stalks d.m.) which almost completely precipitated with lignin.

The value of 64-detector row computed tomography for the exclusion of pulmonary embolism.

Recently, a diagnostic strategy using a clinical decision rule, D-dimer testing and spiral computed tomography (CT) was found to be effective in the evaluation of patients with clinically suspected pulmonary embolism (PE). However, the rate of venous thromboembolic complications in the three-month follow-up of patients with negative CT was still substantial and included fatal events. It was the objective to evaluate the safety of withholding anticoagulants after a normal 64-detector row CT (64-DCT) scan from a cohort of patients with suspected PE. A total of 545 consecutive patients with clinically suspected first episode of PE and either likely pre-test probability of PE (using the simplified Wells score) or unlikely pre-test probability in combination with a positive D-dimer underwent a 64-DCT. 64-DCT scanning was inconclusive in nine patients (1.6%), confirmed the presence of PE in 169 (31%), and ruled out the diagnosis in the remaining 367. During the three-month follow-up of the 367 patients one developed symptomatic distal deep-vein thrombosis (0.27%; 95%CI, 0.0 to 1.51%) and none developed PE (0 %; 95%CI, 0 to 1.0%). We conclude that 64-DCT scanning has the potential to safely exclude the presence of PE virtually in all patients presenting with clinical suspicion of this clinical disorder.

Off-flavours in wines through indirect transfer of volatile organic compounds (VOCs) from coatings.

This paper assesses the impact of volatile organic compounds (VOCs) from the drying of coatings on the sensory characters of corks and wines. According to Italian National Standard Method 11021:2002, a small-scale chamber was used (1) to expose wines to the drying of coatings with both low and high VOCs, and (2) to expose corks to the same coatings. After exposure to the coatings, the corks were then placed in direct contact with wine. Different styles of white, red and rose wines were tested. In both directly exposed wines and in wines after contact with the exposed cork, the taste and smell off-flavour perception and intensity were assessed by a panel of eight experienced wine tasters using a five-point numerical scale according to International Organization for Standardization (ISO) standard methods. The results showed that the sensory characters of wines, especially taste, were influenced by the VOC content of the coatings. The taste off-flavour perception was found to be higher than the smell in wines exposed to coatings with either high or low VOCs contents. Analysis of variance (ANOVA) and Duncan analysis prove that: (1) panellist's answers were significantly different, (2) it was difficult to differentiate the off-flavour perception on the high-level scale, and (3) the panellist off-flavour perceptions versus wine style discriminated the wines into two groups (red and white/rose). For all the wine styles, Pearson's test showed no significant correlation between off-flavour perception levels and the main chemical characters of the wines. For the wines that were in direct contact with the exposed corks, the panellists detect the off-flavours according to the levels of VOCs in the coating and wine styles and they assessed the highest levels of alteration were to the taste.

Modeling of a vapor-phase fungi bioreactor for the abatement of hexane: fluid dynamics and kinetic aspects.

During some previous works, a packed-bed lab-scale biofilter (177 . 10(-6) m3), inoculated with a selected strain of Aspergillus niger had been tested for the abatement of hexane vapors, showing a maximum elimination capacity of 200 g hexane/m3 reactor/h. A steady-state mathematical model taking into account axial dispersion effect was applied to describe the process and predict experimental results, but many model parameters could not be calculated from experimental data. The aim of the present work was to carry out further investigations to accurately determine the dispersion coefficient and the kinetics parameters to verify the effective validity of the model. Analysis of residential time distribution revealed the presence of a certain degree of axial dispersion (dispersion coefficient D of 1.22 . 10(-4) m2/s). Experimental data from kinetic trials carried out in reduced height reactors, together with data from full-scale runs, were elaborated to estimate the kinetic saturation constant (K(s)), the coefficient yield (Y), the maximum growth rate (mu(max)) and maximum substrate degradation rate (r(max)). All these parameters were introduced into the model, which was then solved by simulation software finding a good correlation between experimental and theoretical results.

[Endo-urology in diseases of the upper urinary tract other than tumors and calculi]. / L'endo-urologie dans les affections du haut appareil urinaire autres que les tumeurs et les calculs.

Thirty-three patients underwent percutaneous treatment for upper urinary obstructive disease in our Institute. Cold-knife incision of 16 cases of uretero-pelvic junction obstruction and 4 cases of infundibular stenosis was performed. Balloon dilatation of the caliceal neck was performed in 1 patient with caliceal diverticulum. In 4 of the patients treatment failed requiring open surgical correction. Thirteen patients presented iatrogenic ureteral obstruction: balloon dilatations or cold-knife incisions were performed. Four of the 9 patients evaluable obtained significant benefit from the endourological treatment. Endopyelotomies for UPJ obstruction seem effective and reduce morbidity and operating times. Ureteral obstructions appear less responsive to the endo-urological approach. Definitive conclusions concerning the effectiveness of these procedures requires larger series of patients and longer follow-up.

Echography in vena cava invasion from renal tumors.

The last 4 cases of our case series of renal cell carcinoma (RCC) with caval or cavo-atrial invasion were studied by ultrasonography (US), computerized tomography (CT scan), arteriography (AG) and venocavography (VC) (inferior and/or superior). A comparison is made with these different methods, with particular emphasis on (US). The authors' conclusions are that ultrasound may replace anterograde inferior cavography in the evaluation of thrombotic extension and, in addition, it seems to be capable of eliminating the false-positives or -negatives of this method. AG and VC are no longer necessary to determine the cavo-atrial extension of a tumor thrombus from RCC when US and CT scan are available and are correctly integrated.

CT appearance of generalized von Recklinghausen neurofibromatosis.

Two cases of von Recklinghausen neurofibromatosis (VRN) with thoracic and abdominal involvement are described. Computed tomography demonstrated the typical lesions of this disease: meningoceles, neurofibromas, and skeletal alterations. In both cases lesion morphology and location were similar and characteristic, in particular in the pelvic region. Computed tomography findings in generalized VRN are sufficiently characteristic to be considered diagnostic for this disease.

CT demonstration of portal and superior mesenteric vein thrombosis in hepatocellular carcinoma.

Three cases of hepatocellular carcinoma in which computed tomography (CT) demonstrated thrombosis of the portal vein are reported. In one patient, extension of the thrombus into the superior mesenteric vein was identified as well. The outstanding CT features of portal vein thrombosis were: (a) enlargement of the vein, (b) intraluminal low density area, and (c) hyperdense peripheral ring due to the enhancement of the venous wall. These findings may be useful in differentiating hepatocellular carcinoma from hepatic metastases.