1,721,015 research outputs found
Rischio da Fitofarmaci in Ambiente Agricolo: Elaborazione e Validazione di un Modello Predittivo e Confronto con dati di Monitoraggio Ambientale
No full text"Rischio da fitofarmaci in ambiente agricolo:elaborazione e validazione di un modello predittico e confronto con dati di Monitoraggio Ambientale"
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Analytical method validation for the evaluation of cutaneous occupational exposure to different chemical classes of pesticides
No full textIn occupational exposure to pesticides, validated methodologies are available only in regards to homogeneous chemical classes of substances
and the inhaling exposure, neglecting the cutaneous one that, especially in agriculture, represents an important route of absorption. An analytical
methodology for the simultaneous quantification of different chemical classes of pesticides by using pads as environmental matrix and GC–MS/SIM
as detection method was developed and validated. The extraction step of analytes from pads was optimized by comparing analytes recovery
percentages obtained with different extraction solvents. High recoveries were obtained with ether and, above all, with acetonitrile. Validation
experiments following the Food and Drug Administration Guidelines were carried out.
© 2007 Elsevier B.V. All rights reserved
Criticità e limiti dei metodi di screening immunochimici per la determinazione di sostanze psicotrope in lavoratori addetti a mansioni a rischio
No full textIl lavoro riporta i risultati di uno studio finalizzato alla valutazione delle performance analitiche di un test di screening on-site, scelto tra quelli commercialmente disponibili sulla base delle caratteristiche tecniche fornite dal costruttore. Il disegno sperimentale ha previsto per ciascuna delle sostanze stupefacenti tabulate dalla normativa (cocainici, oppiacei, metadone, amfetamina, metamfetamina, MDMA, buprenorfina, cannabinoidi) l’analisi in triplicato di tre campioni urinari, preparati a partire da urine di tre soggetti non dediti all’uso/abuso di sostanze stupefacenti, addizionate di volta in volta con uno degli otto analiti a tre livelli di concentrazione (una corrispondente al valore di cut-off tabulato e gli altri a concentrazioni superiori). In totale lo studio ha previsto l’analisi di N = 216 campioni (3urine x 3concentrazioni x 3replicati x 8droghe). Ciascun campione è stato successivamente quantificato mediante gas cromatografia/spettrometria di massa, utilizzata quale metodica di riferimento.
Le performance del test di screening sono state valutate in termini di sensibilità diagnostica (VP/(VP+FN) * 100), specificità (VN/(FP+VN) * 100) ed accuratezza ((VP+VN)/(VP+VN+FP+FN)*100).
Sulla base dei risultati ottenuti è possibile affermare che i risultati falsamente positivi all’analisi di screening ottenuta mediante utilizzo di dispositivi immunochimici è attribuibile i)alla non specificità per singolo analita dei test; ii)ad errori di esecuzione del test e/o di interpretazione del risultato da parte dell’analista; iii)alla scelta dei cut-off analitici, in tutti quei casi in cui la sostanza d’abuso è effettivamente presente nel campione esaminato, ma in concentrazione inferiore rispetto al del cut-off stabilito.
I problemi analitici connessi con l’esecuzione dei test di screening on-site e l’inaccuratezza delle determinazioni quando gli analiti siano presenti in concentrazioni prossime al cut-off, pongono nuovi interrogativi sulla veridicità delle percentuali di positività emerse, intorno all’1% contro un valore atteso tra il 3-5% (e calcolato sulla base della percentuale di lavoratori tra la popolazione dedita all’uso di sostanze stupefacenti)
Biological monitoring of nurses exposed to doxorubicin and epirubicin by a validated liquid chromatography/fluorescence detection method
No full textObjectives: Occupational exposure to antineoplastic drugs can represent a potential health
risk for hospital staff. Assessing exposure is the first step in providing a safe work environment;
the present study aimed to perform a biological monitoring (BM) of nurses exposed
to doxorubicin and epirubicin. In order to assure data accuracy and reproducibility, the
high-performance liquid chromatography with fluorescence detection method was validated.
Methods: Validation experiments were carried out according to the Food and Drug Administration
guidelines. A detailed questionnaire about workplace practices and work organization
was administered to 56 nurses of oncology department of two hospitals (A and B) located in southern
Italy. End-shift urine samples were collected. Amounts of drugs handled were registered.
Results: The quantification and detection limits were 1.1 and 0.6 pg ml21 (doxorubicin) and 2.0
and 1.2 pg ml21 (epirubicin); moreover, the analytical method fulfilled all guidelines requirements.
Questionnaire information evidenced that vertical laminar flow hoods were present in both
hospitals, surfaces were cleaned with inappropriate detergents, no antispilling devices were adopted,
and gloves were not changed during the work shift. A lower percentage of positive samples
was found in the hospital where higher amounts of anthracyclines were handled (3.4% in A and
14.8% in B), suggesting individual incorrect working/cleaning practices in hospital A and overall
hygienic standards to be improved in hospital B, where ‘critical practices’ were carried out.
Conclusions: Results showed the crucial role of adopting effective safety precautions and
handling practices to reduce exposure. Environmental and BM should be performed to discriminate
between incorrect personal working modalities and general hygienic standards
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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