Use of Sawing Waste from Zeolitic Tuffs in the Manufacture of Ceramics

This paper investigates the thermal transformation of powders of volcanic tuffs that are used as building stones and aims at thermally transforming them into ceramics. The following positive indications concerning this thermal transformation were found: (1) the structural evolution which brings products similar to traditional ceramics, (2) the good ability to give rise to dense and compact final products, and (3) the good mechanical properties and the lovely appearance of the final products. Nevertheless, the high values of linear shrinkages recorded in this work seem to strongly hinder the thermal transformation of this powder-like waste into ceramics. However, mixing this by-product with other powder-like waste exhibiting higher-dimensional stability, such as those deriving from sawing of granites, appears proper

Executive function impairment in early - treated PKU subjects with normal mental development

Executive functions were studied in 14 early and continuously treated PKU subjects (age 10.8 years, range 8-13) in comparison with controls matched for IQ, sex, age and socioeconomic status. Brain MRI examination was normal in all PKU patients. Neuropsychological evaluation included Wisconsin Card Sorting Test, Rey-Osterreith Complex Figure Test, Elithorn's Perceptual Maze Test, Weigl's Sorting Test, Tower of London, Visual Search and Motor Motor Learning Test. Whatever the IQ, PKU subjects performed worse than controls in tests exploring executive functions. Subgrouping the PKU subjects according to the quality of dietary control for the entire follow-up period (using 400 micromol/L as cut-off value for blood phenylalanine (Phe) concentration) showed that patients with worse dietary control performed more poorly than both the PKU group with the best dietary control and the control group. However, a mild impairment of executive functions was still found in PKU patients with a good dietary control (Phe 400 micromol/L) compared to controls. Concerning the PKU group as a whole, no linear correlation was found between neuropsychological performance and historical and concurrent biochemical parameters. We conclude that (a) PKU patients, even when treated early, rigorously and continuously, show an impairment of frontal lobe functions; (b) a protracted exposure to moderately high levels of Phe can affect frontal lobe functions independently of the possible effect of the same exposure on IQ; (c) in order to reduce the risk of frontal lobe dysfunction, the target of dietary therapy should be to maintain blood Phe concentration below 400 micromol/L

Fate of the preserved aortic root after treatment of acute type A aortic dissection: 23-year follow-up

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Scintimammography with 99mTc-MIBI and magnetic resonance imaging in the evaluation of breast cancer

This study was performed to evaluate the sensitivity and specificity of technetium-99m methoxyisobutylisonitrile (99mTc-MIBI) scintimammography (SMM) and contrast-enhanced magnetic resonance imaging (MRI) in patients with breast masses, using the histological findings as the gold standard. Forty-five consecutive patients with a breast lesion, detected by self-examination, physical examination or screening mammography, underwent SMM and MRI. In 38 cases (84.5%), the histopathology was malignant; the breast cancers ranged from 3 to 100 mm in diameter (mean 22 mm). In the overall patient group, MRI showed a slightly higher sensitivity than SMM (92% vs 84%), but SMM showed a better specificity: 71% vs 42%. The accuracy was 82% and 84% for SMM and MRI respectively. To evaluate the influence of lesion size on the results, patients with lesions ≤20 mm and ≤15 mm were examined. In patients with lesions ≤20 mm, the sensitivity of SMM and MRI decreased to 64% and 82% respectively, while SMM again displayed considerably better specificity: 83% vs 50% for MRI. The accuracy of SMM and MRI was 64% and 82% respectively. In patients with lesions ≤15 mm, SMM again showed better specificity (75% vs 50%), while MRI displayed better sensitivity and accuracy (sensitivity, 81% vs 62%; accuracy, 75% vs 65%). In this study the specificity of SMM in patients with breast lesions was thus superior to that of MRI. The combination of SMM and MRI may be used in those patients with equivocal findings at mammography and ultrasound to reduce the number of unnecessary surgical biopsies

Demosponge diversity from North Sulawesi, with the description of six new species

Volume: 680Start Page: 105End Page: 15

Silica Meets Tannic Acid: Designing Green Nanoplatforms for Environment Preservation

Hybrid tannic acid-silica-based porous nanoparticles, TA-SiO2 NPs, have been synthesized under mild conditions in the presence of green and renewable tannic acid biopolymer, a glycoside polymer of gallic acid present in a large part of plants. Tannic acid (TA) was exploited as both a structuring directing agent and green chelating site for heavy metal ions recovery from aqueous solu-tions. Particles morphologies and porosity were easily tuned by varying the TA initial amount. The sample produced with the largest TA amount showed a specific surface area an order of magnitude larger than silica nanoparticles. The adsorption performance was investigated by using TA-5SiO2 NPs as adsorbents for copper (II) ions from an aqueous solution. The effects of the initial Cu2+ ions concentration and the pH values on the adsorption capability were also investigated. The resulting TA-SiO2 NPs exhibited a different adsorption behaviour towards Cu2+, which was demonstrated through different tests. The largest adsorption (i.e., ~50 wt% of the initial Cu2+ amount) was obtained with the more porous nanoplatforms bearing a higher final TA content. The TA-nanoplatforms, stable in pH value around neutral conditions, can be easily produced and their use would well comply with a green strategy to reduce wastewater pollution

Parameters Expediting the Thermal Conversion of Ba-Exchanged Zeolite A to Monoclinic Celsian

Four samples of Ba-exchanged zeolite A, bearing small residual amounts of Na (0.27, 0.43, 0.58, and 0.74 meq/g), were thermally treated in the temperature range 200–1500∘C for times up to 28 hours. The same samples were pressed at 30 and 60 MPa to form cylindrical pellets which were thermally treated at 1300∘C for 5 hours. All materials were characterized by room temperature XRD. The sequence of thermal transformations that Ba-exchanged zeolite A undergoes (zeolite → amorphous phase → hexacelsian → monoclinic celsian) and the strong mineralizing action developed by Na are confirmed. Pressing the Ba-exchanged zeolite A powder-like samples to obtain cylindrical pellets is found to expedite the sluggish final phase transition hexacelsian → monoclinic celsian. The optimum residual Na content of Ba-exchanged zeolite A for transformation into monoclinic celsian is assessed to be between 0.27 and 0.43 meq/g