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11.
S. Caroli R. Cresti M. Spagnoli M. Alessandrelli G. Forte S. D'Ilio F. Chiodo 《Microchemical Journal》2000,67(1-3)
The growing interest of the public opinion in environmental problems has resulted in the establishment of national and international norms and regulations. Among others, the protection of human health requires the constant monitoring of several groups of potentially toxic substances as well as of their residues in live animals and their products. For this reason in recent years the European Commission decided to establish four Community Reference Laboratories (CRLs) for the analysis of residues in products of animal origin. The current mandate and operative conditions of the CRLs are described in the Council Directive 96/23/EC of 29 April 1996, which has the goal of promoting and supporting the harmonization of approaches among National Reference Laboratories (NRLs). In this context the CRL at the Istituto Superiore di Sanità of Rome is responsible for chemical elements, organochlorine compounds (including PCBs), carbamates, pyrethroids and organophosphorus compounds. The supply of updated information on the literature of relevance to the tasks of the NRLs is one of the duties of the Rome CRL. To this end, the so-called Cardbox Database has been set up, which for the time being is fully operative for chemical elements and organochlorine compounds. 相似文献
12.
Observations of the atmospheric boundary layer across the land-sea transition zone using a scanning Mie lidar 总被引:1,自引:0,他引:1
F. Gao K. Bergant B. Forte X.-Q. Song S. Stani? M. Zavrtanik 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(2):182-188
Optical properties of the atmospheric boundary layer (ABL) above the land-sea transition interface were measured using a scanning Mie lidar located 30 km away from the Adriatic coast. Based on the two-dimensional range-height-indicator scans, detailed information on the ABL was obtained, including parameters such as atmospheric optical depth, aerosol extinction coefficient and the height of the ABL. The presented case study indicates that the height of the ABL in the land-sea transition zone and the adjacent mountainous region was changing rapidly due to highly variable atmospheric conditions. 相似文献
13.
Gustavo Forte Alberto Lencina Myrian Tebaldi Néstor Bolognini 《Optics Communications》2011,284(10-11):2494-2499
The self-image phenomenon by a volume grating is proposed and theoretically analyzed. A theoretical model based on a path integral formulation to describe wave propagation through the grating inhomogeneous medium is applied. A modified version of the scalar diffraction theory Fresnel propagator is obtained which allows calculating the diffracted field amplitude by the grating. The proposed model is applied to amplitude and/or phase volume gratings. Remarkable features appear, in particular at the fractional Talbot distance 0.125zT. In this case, if an in-phase real and imaginary grating modulation is considered a self-image intensity profile is observed for determined values of the absorptive and refractive parameters. On the other hand, a spatial comb intensity profile for a near half period shift between the real and imaginary grating modulations is found. 相似文献
14.
S. Caroli M. Spagnoli G. Forte M. Alessandrelli R. Cresti S. D'Ilio J. Pauwels G. N. Kramer Gy. Zray 《Microchemical Journal》2000,67(1-3)
In the framework of the activities of the Community Reference Laboratory (CRL) for residues at the Istituto Superiore di Sanità (ISS) of Rome, a number of proficiency tests were performed in order to assess and improve, wherever necessary, the quality of regulatory residue analysis within the EU. In this context, a pilot study was undertaken with the purpose of ascertaining the feasibility of a project for the certification of a new reference material for trace elements in bovine muscle. On behalf of the ISS, approximately 70 kg of bovine muscle, collected at a slaughterhouse in Geel (Belgium), were freeze-dried, homogenized, stabilized and bottled under argon atmosphere by the Institute for Reference Materials and Measurements, Joint Research Centre, European Commission (IRMM-JRC-EC). Preliminary analyses were carried out with Quadrupole (Q) and High Resolution (HR) Inductively Coupled Plasma Mass Spectrometry (ICP-MS) to evaluate the content of As, Cd, Cu and Pb, whereas the Flow Injection Mercury System (FIMS) was used to quantify Hg. Digestion of the matrix was achieved by acid-assisted microwave irradiation. The mean values of experimentally obtained data were the following (in nanograms per gram): As, 24.2±1.2; Cd, 5.48±0.29; Cu, 4765±95; Hg, 3.37±0.73; and Pb, 184±7. Subsequently, 16 National Reference Laboratories (NRLs) for residues in the Member States plus the Norwegian one and eight Italian public laboratories were accepted to participate in the project and received one bottle of the freeze-dried bovine muscle. The laboratories were requested to perform three different analytical runs (in three different days), each consisting of three individual measurements. Preliminary results showed good agreement and fair evidence for homogeneity of the entire mass, thus setting the stage for the future certification of this candidate CRM. 相似文献
15.
Olson IA Bacon WA Baez Sosa YY Delaney KM Forte SA Guglielmo MA Hill AN Kiesow KH Langenbacher RE Xun Y Young RO Bowyer WJ 《The journal of physical chemistry. A》2011,115(40):11001-11007
We describe three new strategies for determining heterogeneous reaction rates using photomicroscopy to measure the rate of retreat of metal surfaces: (i) spheres in a stirred solution, (ii) microscopic powder in an unstirred solution, and (iii) spheres on a rotating shaft. The strategies are applied to indium-mediated allylation (IMA), which is a powerful tool for synthetic chemists because of its stereoselectivity, broad applicability, and high yields. The rate-limiting step of IMA, reaction of allyl halides at indium metal surfaces, is shown to be fast, with a minimum value of the heterogeneous rate constant of 1 × 10(-2) cm/s, an order of magnitude faster than the previously determined minimum value. The strategies described here can be applied to any reaction in which the surface is retreating or advancing, thereby broadening the applicability of photomicroscopy to measuring heterogeneous reaction kinetics. 相似文献
16.
Badaloni E Barbarino M Cabri W D'Acquarica I Forte M Gasparrini F Giorgi F Pierini M Simone P Ursini O Villani C 《Journal of chromatography. A》2011,1218(25):3862-3875
New monolithic HPLC columns were prepared by γ-radiation-triggered polymerization of hexyl methacrylate and ethylene glycol dimethacrylate monomers in the presence of porogenic solvents. Polymerization was carried out directly within capillary (250-200 μm I.D.) and nano (100-75 μm I.D.) fused-silica tubes yielding highly efficient columns for cap(nano)-LC applications. The columns were applied in the complete separation of core (H2A, H2B, H3, and H4) and linker (H1) histones under gradient elution with UV and/or electrospray ionization (ESI) ion trap mass spectrometry (MS) detections. Large selectivity towards H1, H2A-1, H2A-2, H2B, H3-1, H3-2 and H4 histones and complete separation were obtained within 8 min time windows, using fast gradients and very high linear flow velocities, up to 11 mm/s for high throughput applications. The method developed was the basis of a simple and efficient protocol for the evaluation of post-translational modifications (PTMs) of histones from NCI-H460 human non-small-cell lung cancer (NSCLC) and HCT-116 human colorectal carcinoma cells. The study was extended to monitoring the level of histone acetylation after inhibition of Histone DeACetylase (HDAC) enzymes with suberoylanilide hydroxamic acid (SAHA), the first HDAC inhibitor approved by the FDA for cancer therapy. Attractive features of our cap(nano)-LC/MS approach are the short analysis time, the minute amount of sample required to complete the whole procedure and the stability of the polymethacrylate-based columns. A lab-made software package ClustMass was ad hoc developed and used to elaborate deconvoluted mass spectral data (aligning, averaging, clustering) and calculate the potency of HDAC inhibitors, expressed through a Relative half maximal Inhibitory Concentration parameter, namely R_IC(50) and an averaged acetylation degree. 相似文献
17.
The vibrational predissociation of HD2 + is modelled in terms of quantum-mechanical tunnelling through a minimal centrifugal barrier at given total angular momentum, J, and with statistical intermode coupling behind the barrier. It is shown that the observed strong preference for the H+ + D 2 predissociation channel (over D+ + HD) is consistent with an experimental preference for J values in the range 0 < J < 25, a range which is also shown to be consistent with the observed H3 + preferred range of kinetic energy release. A correlation between the total angular momentum and the kinetic energy release is also predicted. 相似文献
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Riassunto Si stabiliscono alcune proprietà riguardanti i valori al contorno delle soluzioni di un sistema di equazioni funzionali connesso
con la teoria dell'informazione senza probabilità. Si ottiene poi in particolare una caratterizzazione per talune misure di
informazione compositive a traccia shannoniana.
Résumé On établit certaines propriétés de trace pour les solutions continues d'un système d'équations fonctionelles qu'on rencontre dans la théorie de l'information sans probabilité. D'après ?a on obtient en particulier une caractérisation de certaines mesures compositives à trace shannonienne.相似文献