186,161 research outputs found
Gli addotti all'emoglobina nel monitoraggio biologico delle esposizioni professionale: il caso del cobalto e della dimetilformammide
No full textUn gruppo di lavoratori esposti a nanoparticelle di cobalto e ossido di cobalto è stato coinvolto al fine di caratterizzare la cinetica del cobalto nelle urine, nel sangue intero e nella globina. In una prima fase è stata confermata la piuttosto rapida cinetica del cobalto in campioni di urine (emivita di poche ore). La seconda fase ha comportato la raccolta di campioni di urine, una volta alla settimana per 16 settimane consecutive al fine di avere un’indicazione sui livelli medi di esposizione individuale e rapportarla alle concentrazioni del cobalto nella globina. I risultati hanno messo in evidenza una relazione lineare molto stretta tra la media delle concentrazioni del cobalto nei campioni di urina raccolti nei 4 mesi precedenti e le concentrazioni del metallo nella globina. Anche il sangue intero ha presentato concentrazioni di cobalto in relazione lineare con i risultati della globina. Questo dato contrastava con i dati della letteratura che suggerivano una emivita del cobalto nel sangue piuttosto breve. In una terza fase abbiamo raccolto campioni di sangue al termine dell’ultima giornata lavorativa prima delle vacanze natalizie e dopo 18 giorni (cioè all’inizio della ripresa del lavoro) al fine di valutare il tempo di decadimento del cobalto nella globina e la sua emivita nel sangue intero. I risultati hanno messo in evidenza che l’emivita del cobalto nel sangue è di circa 10 giorni e che nella globina decade lentamente in logico parallelismo alla distruzione dei globuli rossi
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Intossicazione acuta da anidride carbonica : descrizione di due casi mortali
No full textBACKGROUND: Carbon dioxide (CO2), a very high density gas, tends to stratify at the lowest levels of the atmosphere. It can be produced by neutral geothermal emissions, fermentative processes or by human and industrial activity. When carbon dioxide concentrations rise to a very high level in a confined and poorly ventilated space, the anoxic hazard is a very important cause of severe accidents that can involve workers and rescuers. At CO2 levels higher than 20% there is a very high risk of a fatal accident, also considering the odourless feature of this gas. OBJECT: Two fatal accidents in workers are described which occurred during inspection of a concrete well, built as a part of sewerage network in a rural area. In the weeks after the accident, composition and concentration of gases inside the well were analysed. We also considered the influence of an organic fertilizer called "pollina" which was found on the ground around the concrete well, in order to ascertain whether fermentation could alter the gas composition inside the well. METHODS: Samples of air and water were collected in the well and samples of the organic fertilizer (pollina) on the ground surrounding the concrete well were also taken. Different quantities of organic fertilizer (pollina) with or without water were incubated in airtight glass bottles and placed in a dark room at 20 degrees C temperature; analysis of air inside the glass bottles was performed after 7 and 18 days of incubation. All the samples of air and water were analysed by gas-chromatographic-mass-spectrometry. RESULTS: Analysis of the air samples collected inside the well after 2, 16 and 18 weeks after the accident showed a low concentration of O2 (range 4.2-9%), a high concentration of CO2 (range 5.9-12.3%), a normal level of N2 (range 78-85%) and a concentration of N2O between 0.03 and 0.19%. In water collected 2 weeks after the accident at the bottom of the concrete well, CO2 and N2O concentrations of respectively 222 mg/L and 2 mg/L were measured. In the bottles with "pollina" we found, at different times of incubation, high concentrations of CO2 (highest value 25.2%), low levels of O2 (lowest value 0.5%) and negligible concentrations of N2O (< 0.015%). CONCLUSIONS: All these findings suggest that the atmosphere inside the concrete well was altered by the fermentative processes of pollina. The death of the two workers, caused by a poorly oxygenated atmosphere with a high concentration of carbon dioxide, can be classified under the confined space hypoxic syndrome (CSHS)
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
DNA damage kinetics (micronucleus and comet assay) in buccal mucosa cells of subjects after metal fixed appliances
No full textOrthodontic appliances are usually made of stainless steel, which contains metals (nickel, chromium, etc.) that have been associated with DNA damage. Therefore, data on the biocompatibility of alloys have created growing interest. The aim of this study was to determine the genetic toxicity associated with the kinetics of metal release from fixed orthodontic appliances in mucosa cells. Mucosa samples were collected, by brushing of internal cheeks of 25 patients, before (T0) and after 7 (T7), 15 (T15), 30 (T30), 60 (T60) and 90 (T90) days of orthodontic treatment. The cells were isolated for nickel (Ni), chromium (Cr) and titanium (Ti) content by inductively coupled plasma mass spectrometry (ICP-MS), glutathione (GSH) levels and the genotoxicity were evaluated by micronucleus (MN) and comet (CA) assay. The results indicate that after the placement of the orthodontic appliances there is a significant increase in Ni and Cr cellular concentration (p < 0.05 and p < 0.001, respectively), but not for Ti. DNA damage, as assessed by CA, is significantly high already at T15 (p < 0.001) in reference to T0. Conversely, there is a significant increase in MN frequency 30 days after the beginning of the orthodontic treatment (p < 0.001). These results show that CA detects DNA damages induced very early after exposure to genotoxic agents, while MN reveals after 30 days structural damages (chromosome breakage or spindle dysfunction), that occur in the dividing basal layer. CA and MN are significantly correlated each other, with day-exposure and with cellular Cr
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Edward P. Wimberly, ITC, July 2011
No full textThis video is a conversation with Dr. Edward P. Wimberly. Dr. Wimberly talks about his book, "No Shame in Wesley's Gospel: A Twenty-First Century Pastoral Gospel". Brad Ost, AUC Woodruff Library, is the interviewer
Author Rights and Scholarly Publishing
No full textOriginally posted at
http://blog.library.gsu.edu/2014/10/24/author-rights-and-scholarly-publishing/</p
- …
