proficiency testing as a tool to assess quality of data the experience of the eu reference laboratory for chemical elements in food of animal origin

AbstractQuality and reliability of analytical results are, in general, key issues for all laboratories but become a top priority for laboratories accredited according to ISO/IEC 17025:2005. In this international standard the proficiency testing (PT) is regarded as a means to assure the validity of results. Nowadays, the proved competence of laboratories is an essential requirement especially for that structures that are involved in the official controls aimed at ensuring the safety of EU food products and the public health. To guarantee the EU consumers, the Council and the Commission have designated 28 European Union Reference Laboratories (EURLs) for food and feed, whose main role is to contribute to the standardization of analytical methods and to the harmonization of performance among the EU National Reference Laboratories (NRLs) to reach a comparable level of quality in the analytical data among all Member States. With this aim, the organization of PTs is a task that each EURL has to accomplish. Over the last 15 years, the EURL for chemical elements in food of animal origin (EURL-CEFAO) have organized 32 PTs on determination of total As, Cd, Pb and total Hg in meat, milk, fish and offal for the benefit of its network of NRLs. Some specific aspects of this activity will be discussed (e.g. preparation and characterization of PT materials, statistical evaluation of data, follow-up actions). Finally, based on the EURL-CEFAO experience, it will be demonstrated that the participation into PTs on a regular basis can result in an improvement of the laboratory's performance as well as in the harmonization of the results submitted by participants

La scrittura di Sant’Ignazio di Loyola tra paleografia e chimica

The article is composed of two different parts, both resulting from the palaeographic analysis of the Diario spirituale written by Ignatius of Loyola. The first part outlines Spain’s graphic panorama during the 16th century and contextualises the writing of Saint Ignazio examining its peculiarities and the used abbreviation systems. The second part studies the writing method on the basis of the spectrographic analysis of the ink, with particular attention given to ink changes and corrections made during the writing

Lo statuto del Collegio dei giudici e avvocati di Verona (1399)

edizione critica del testo statutario, traduzione e saggi introduttiv

Synthesis of Alkyl-Substituted Six-Membered Lactones Through Ring-Closing Metathesis of Homoallyl Acrylates. An Easy Route to Pyran-2-ones, Constituents of Tobacco Flavor

The ring-closing metathesis (RCM) reactions of homoallylic acrylates bearing alkyl substituents on various positions of their skeleton afford the corresponding pentenolides in the presence of carbene ruthenium catalysts. For R-3 = R-4 = H, or R-3 = Me, R-4 = H, the reactions are catalyzed by complex [RuCl2(PCy3)(2)(CHPh)], while a second-generation Grubbs catalyst is required when R-3 = H and R-4 = Me, R-3 = R-4 = Me, or R-3 = i-Pr and R-4 = H. Alkyl substitution at the homoallylic carbon (R-1, R-2) increases the yield of the reaction when both the acrylic and/or homoallylic double bonds are methyl-substituted. The interaction of the catalyst with the substrate in the initiation stage involves the homoallylic double bond rather than the acrylic moiety, and the resulting alkylidene species from the first-generation Grubbs catalyst can be observed by H-1 and P-31 NMR. The racemic tobacco constituents 4-isopropyl-5,6-dihydropyran-2-one and 4-isopropyltetrahydropyran-2-one are prepared via a short reaction sequence, involving the RCM reaction as the key transformation

Purity control of some Chinese crude herbal drugs marketed in Italy

In the present study, 10 Chinese crude herbal drugs marketed in Italy (Radix Ginseng, Radix Astragali, Rhizoma Coptidis, Rhizoma Atractylodis Macrocephalae, Radix Bupleuri, Radix Rehmanniae, Radix Paeoniae Alba, Pericarpium Citri Reticulatae, Radix Polygalae, Radix Salviae Miltiorrhizae) were analysed by the following purity assays: foreign matter, total ash, microbial and heavy metal contamination. The presence of parasites was shown in two samples; moreover, level of ash (in three samples), lead content (in one sample) and total viable aerobic count (in one sample), were higher than the limits set by the European or Italian Pharmacopoeias. Our results show some purity issues and underline the importance of the quality control

Management of patients with suspected or confirmed COVID-19, in the radiology department

Objectives: From December 2019, a novel coronavirus disease named COVID-19 was reported in China. Within 3 months, the World Health Organization defined COVID-19 as a pandemic, with more than 370,000 cases and 16,000 deaths worldwide. In consideration of the crucial role of diagnostic testing during COVID-19, the aim of this technical note was to provide a complete synthesis of approaches implemented for the management of suspected or confirmed COVID-19 patients. Key findings: The planning of a robust plan to prevent the transmission of the virus to patients and department staff members should be fundamental in each radiology service. Moreover, the speed of spread and the incidence of the pandemic make it necessary to optimize the use of personal protective devices and dedicated COVID-19 equipment, given the limited availability of supplies. Conclusion: In the management of radiographic and CT imaging, staff should take special precautions to limit contamination between patients and other patients or professionals. Implications for practice: An isolated imaging room should be dedicated to suspected or confirmed COVID-19 cases, including radiography and CT scanners. This paper will provide guidance concerning disposable protective gear to be utilized, as well as on the cleaning and sanitation of radiology room and equipment

Serum selenium concentration and disease progress in patients with HIV infection

The selenium concentration in the serum of 67 patients with HIV infection was measured to determine whether selenium deficiency occurred in the different stages of the disease. In the first stage of the study, patients were divided into four groups: symptom-free subjects, PGL (persistent generalized lymphadenopathy), ARC (AIDS related complex), and AIDS (acquired immunodeficiency syndrome). Selenium concentrations were normal in HIV antibody positive symptom-free subjects (1.18 +/- 0.27 mumol/L) and lower than normal in the other three groups (p less than 0.001). There was a significant correlation (p less than 0.001) between selenium levels and values of hemoglobin and erythrocyte sedimentation rate. Selenium deficiency was in no case associated with a lack of zinc in serum (also determined in all patients). In the second stage of the study, 12 patients were treated for a period of two months with low doses of selenium to assess whether such supplementation was able to restore their impaired immunological and hematological functions. The therapy increased serum selenium concentrations (from 0.77 +/- 0.23 to 1.44 +/- 0.41 mumol/L) and symptomatic improvements were noted. However, no changes were observed in the immunological and hematological parameters