Organic-Inorganic Hybrid Fillers for The Controlled Release of Antioxidants

the barrier provided by the inorganic domains of organic-inorganic hybrids towards the absorption of low molecular weight penetrants was used in this study as a basis for the development of systems capable of desorbing antioxidants at a slow rate. Polyethyleneoxide-silica hybrids, compatibilized with glycidoxylpropyltrimethoxysilane, were used as carriers of conventional stabilizers for polymers, respectively two phenolic antioxidants and one hindered aromatic diamine system. Ternary phase diagrams were produced in order to determine the “compatibile compositions” using DSC to measure changes in melting point and enthalpy of the antioxidant and polyethylene oxide (PEO). A compatible composition of PEO-silica-BHT (tert. butyl hydroxyl toluene) was used to produce a filler, which was pressed on the form of a fine powder between two polyamide-6 films and subsequently sandwiched with further seven layers of fresh films. The multiple-film stack was aged first in an air circulated oven at 60 °C for 360 days and then for further 475 days at ambient atmospheric conditions. The concentration of carbonyl groups in the aged films was monitored by ATR-IR spectroscopy. A sigmoidal increase was found for the amount of new carbonyl groups formed, starting from the inside layer nearest to the source of antioxidant. This confirms that the antioxidant has diffused from the filler into the surrounding polymer matrix and has reduced the rate of evolution of carbonyl groups resulting from oxidative degradation reactions.     

Serial gadolinium-DTPA of spinal cord MRI in multiple sclerosis: triple vs. single dose

We compared the sensitivity of single and triple dose Gd-DTPA magnetic resonance imaging (MRI) in detecting enhancing lesions in the spinal cord (SC) from 15 patients with multiple sclerosis (MS). The patients were examined monthly on four occasions. We detected two enhancing lesions in two of 15 (13%) patients when a single dose of Gd-DTPA was used. No additional lesions were detected when a triple dose of Gd-DTPA was used. These results 1) confirm that enhanced spinal cord imaging does not significantly increase the detection of active lesions in MS, 2) they do not support the general application of triple dose Gd-DTPA when examining the SC but 3) suggest that further studies taking into account SC symptoms are necessary.     

Assessment of Summer Trends of Tropospheric Radon Isotopes in a Coastal Antarctic Station (Terra Nova Bay)

This work reports the first results of atmospheric radon measurements performed at the Italian Antarctic station located at Terra Nova Bay (74.69°S; 164.12°E) during summer campaigns of 1995-96, 1996-97 and 1997-98. Mean²²²Rn concentrations was 0.51 - 0.43 Bq m^m3 (median = 0.37 Bq m^m3), and ranged from 0.01 to 2.74 Bq m^m3 . On the average, these values were considered high, in comparison to results reported for other sites in Antarctica at equivalent latitudes. This could be explained by two causes: radon data for Terra Nova Bay were only for the summer period, when the ice-free area is at its maximum and thus the radon emission to the atmosphere; and by the larger ice-free area at Terra Nova Bay compared, for example, to measurements taken at another Antarctic site by the same technique (Ferraz station - 62°05'S; 058°23.5'W). The mean ²²²Rn to ²²⁰Rn activity ratio was 4.4 - 4.2, ranging between 0.1 and 45.3. The highest ratios indicated that some of observed surges of concentration of ²²²Rn could be attributed to not local sources. Lower radon concentrations were observed during katabatic wind events. The diurnal radon variation followed the general trend observed for continental areas located at lower latitudes.     

The Chernobyl accident: the radioactive contamination in the area of Lake Como and in other Northern Italy sites

Summary The radioactive cloud released during the Chernobyl accident reached the Po Plain and Lombardy in the night of April 30, 1986; the cloud remained in the northern Italian skies for a few days and then disappeared either dispersed by winds or washed by rains. The evidence in the atmosphere of radionuclides as tellurium, iodine, cesium was promply observed by the Istituto di Fisica. The intense rain, in the first week of May, washed the radioactivity and the fallout contaminated the land, soil, grass and vegetables. The present work concerns the overall contamination of the Northern Italy territory and in particular the radioactive fallout in the Alpine region. Samples of soil have been measured at the gamma-spectroscope; a linear correlation is found between the radionuclide concentration in soil samples and the rain intensity, when appropriate deposition models are considered. A number of measurements has been done on Lake Como ecosystem: sediments, plankton, fishes and the overall fallout in the lake area have been investigated.

---

Riassunto La nube radioattiva sprigionatasi nel corso dell'incidente al reattore nucleare di Chernobyl si è dispersa nei cieli lombardi fra la notte del 30 aprile 1986 e i primi giorni di maggio. La presenza di radioelementi nell'aria—tellurio, iodio, cesio—è stata osservata dalle numerose stazioni operanti nella pianura padana. Le piogge dei primi giorni di maggio, cadute soprattutto nelle zone prealpine, hanno trascinato al suolo consistenti quantità di radioelementi. Al fine di rilevare la correlazione fra pioggia e ricadute sono stati prelevati oltre un centinaio di campioni di terreno; i contenuti di radioelementi, e in particolare il cesio, sono misurati a mezzo di spettrometro gamma e risultano in buon accordo con i modelli di deposizione. Si rilevano particolarmente elevati i livelli di ricaduta nella zona del lago di Como e delle adiacenti vallate; un esame dei contenuti di radioelementi nell'ecosistema lacustre completa l'analisi.

     

Fit-for-purpose in veterinary drug residue analysis: development and validation of an LC-MS/MS method for the screening of thirty illicit drugs in bovine urine

A selective and sensitive method for screening 31 analytes (nine corticosteroids, eight β‐agonists, seven anabolic steroids, six promazines and zeranol) in bovine urine was validated according to 2002/657/EC guidelines. Upon optimization of sample treatment conditions, the extraction was performed by diethylether at pH 9, after deconjugation. Extraction yields (R%) proved higher than 70% for 19 analytes, 50<R%<70 for 5 analytes, lower than 50% but reproducible for the remaining six analytes. The analyses were carried out using HPLC‐ESI‐MS/MS. The method sensitivity proved high enough to largely exceed the CCβ requirements of the Italian residue detection plan, ranging from 1 to 3 ng/mL (20 ng/mL for promazines). The present method allowed the simultaneous analysis of most drugs for which the European legislation prescribes official controls. Its practical applicability was verified on 494 real samples as an alternative to the traditional screening protocols based on multiple immunometric analysis, demonstrating high efficiency and comprehensive investigation capacity, allowing epidemiological assessment of the current trends in cattle breeding drug abuse. Among non‐compliant results, nine borderline cases of growth‐promoters illegal treatments, making use of long‐term low‐dosage administrations and typically yielding urine residues below the cut‐off value for immunochemical methods, were detected by using the present LC‐MS/MS method.     

Characterisation of the different hands in the composition of a 14th century breviary by means of portable XRF analysis and complementary techniques

A 14th‐century breviary known as Breviario di San Michele della Chiusa, produced at the disposal of the monks of Sacra di San Michele abbey (near Turin, Italy) has been analysed in order to identify the different authors who contributed in its making. The study aimed at revealing how many scribes composed the text and the musical notations and how many artists worked for miniatures and for the decorations of initials. All inks and decorative features have been analysed by means of portable X‐ray fluorescence spectrometry for determining elemental distribution and by means of ultraviolet–Visible diffuse reflectance spectrophotometry with optic fibres and spectrofluorimetry for identifying colourants. The results on non‐invasive measurements highlighted that at least 11 persons (six scribes for the text, two scribes for the musical notations, two artists for initials and filigrees and one artist for the full‐page miniature at f. 208v) were at work at the Breviario. Moreover, the black inks used for text and notes have an anomalous composition, being iron gall inks with a larger than usual amount of zinc, possibly as a consequence of the use of vitriols made from goslarite; this suggests that the scribes could come from Northern Europe. The presence of traces of bismuth in blue paints also suggested the provenance of azurite from Central or Northern Europe. Copyright © 2017 John Wiley & Sons, Ltd.     

Mucin/carbopol matrix to immobilize oxalate oxidase in a urine oxalate amperometric biosensor

An enzymatic amperometric electrode with extended analytical range and improved stability for oxalate determination has been developed. Glutarlaldehyde/mucin/carbopol matrix was used for the crosslinking of the enzyme between polymeric membranes to form a classical laminate construction (sandwich) and compared with the glutaraldehyde/mucin/enzyme and glutaraldehyde/albumin/enzyme.The use of a sulphonated membrane as internal membrane allowed rejection of the most important electrooxidable urine interferents. The recovery assays were highly satisfactory. The wide linear response in the range 2-400 μM after 1/10 urine dilution (corresponding to 20-4000 μM) made it suitable for clinical range. High correlation with the standard spectrophotometric method was obtained (r² = 0.98, y = 0.89x, n = 25).     

Stability and degradation products of imipenem applying high‐resolution mass spectrometry: An analytical study focused on solutions for infusion

Carbapenems show recognized instability in aqueous solutions; therefore some care must be taken in their handling and preparation and their use in the hospital environment. The stability and degradation products of imipenem were investigated from conditions that simulate its clinical use. For this, a simple stability‐indicating method by HPLC‐DAD was validated with a focus on the quantitation of drug concentration remaining from infusion solutions (sodium chloride 0.9% and glucose 5%). The degradation products formed were identified by high‐resolution mass spectrometry (ESI‐Q‐TOF‐MS/MS), with detection of the [M + H]⁺ ions at m/z 318 (DP‐1), m/z 599 (DP‐2) and m/z 658 (DP‐3). The most probable elemental compositions were obtained with a high degree of confidence, where the error between the masses observed and calculated was 1.25 ppm for DP‐1, ?0.33 ppm for DP‐2 and 1.82 ppm for DP‐3. The DP‐1 degradation product resulted from cleavage of the β‐lactam ring; DP‐2 corresponded to the drug dimer; and DP‐3 was generated from the interaction between imipenem and cilastatin. The proposed method provides a safe and reliable alternative for the quantitation of imipenem, and the stability data obtained by ESI‐Q‐TOF help in understanding the drug behavior under the conditions of clinical use.