1,720,964 research outputs found
Zinc and copper levels in serum, urine and hair of humans in relation to blood pressure
No full textZinc and copper status was evaluated in 63 early hypertensives and compared with that of 63 normotensives matched for sex, age, smoking habits and body mass index. Zinc and copper in serum, urine and hair were measured, and the serum activity of two zinc-dependent enzymes (AP and LDH) were analysed. Mean urinary copper concentration in patients was 14.11 micrograms g-1 creatinine compared with 9.16 micrograms g-1 creatinine in normotensive subjects (paired "t" = 3.94, p less than 0.001). Serum AP and LDH were significantly decreased (16 and 36%, respectively) in the patients compared with controls, although almost all values fell within the normal range of activities. Systolic and diastolic pressures were significantly and positively correlated to urinary copper excretion. These correlations were still apparent after correcting blood pressure values for other urinary measurements. Blood pressure levels (both systolic and diastolic) were also negatively correlated with the two zinc-dependent enzymes
Cadmium in blood, urine and hair related to human hypertension
No full textA case-control study was performed to assess whether cadmium is related to hypertension in a non-occupationally exposed population. 63 male subjects affected by mild stable hypertension, pharmacologically untreated, were investigated together with 63 male normotensive controls individually matched for sex, age, body mass index, smoking habits and work activities. Cadmium in blood, zinc and copper in serum, the three elements in urine and hair, together with some biological parameters involved in pathogenesis of hypertension, were investigated. The mean Cd blood value in hypertensives (H) was 0.58 micrograms/L vs 0.44 micrograms/L in normotensives (N) (t = 2.03; p less than 0.05) with a greater difference in non-smokers (0.41 micrograms/L vs 0.25 micrograms/L) (t = 2.69, p less than 0.01). Furthermore, both systolic and diastolic blood pressure were significantly related to cadmium blood levels (r = 0.20 and 0.19 respectively, p less than 0.05). Smoking habit affected cadmium levels only in the blood, not in the other biological matrices examined. No significant difference of cadmium content in urine and hair was found between normotensives and hypertensives but Cd/Cu ratio in urine was significantly lowered in the second grou
Monitoraggio dell'esposizione professionale ad anestetici volatili in sala operatoria: misurazioni ambientali e biologiche
No full textSono state determinate le concentrazioni di protossido d’azoto (N2O) e isofluorano in campioni ambientali e urinari di soggetti professionalmente esposti ad anestetici volatili nelle sale operatorie di un ospedale emiliano. Lo scopo era quello di valutare: se per stimare l’esposizione personale sia utilizzabile un analizzatore automatico (spettrometro Brüel & Kjaer 1302) per campionamenti in posizione fissa (“zona anestesista” e “zona chirurgo/ strumentista”); se con periodici controlli dell’esposizione si possa ottenere una riduzione della stessa; se l’esposizione a N2O e isofluorano sia contenuta entro i rispettivi valori limite; se ci sia differente esposizione tra anestesisti e chirurghi/strumentisti. Sono stati effettuati due controlli dell’esposizione ad anestetici distanziati di sei mesi: nel primo l’esposizione è stata misurata mediante lo spettrometro, nel secondo tramite campionatori personali passivi. Nel primo controllo sono state raccolte informazioni sui periodi di presenza del personale in sala. Le concentrazioni ambientali di N2O ottenute con il campionatore fisso sono risultate correlate con quelle urinarie. I livelli urinari di N2O ricavati dalla retta di regressione sono risultati sovrapponibili a quelli ottenuti con i campionatori personali. I livelli ambientali e urinari di N2O sono significativamente diminuiti dal primo al secondo controllo. Nel secondo rilevamento il 70% dei soggetti ha presentato un’esposizione a N2O e isofluorano contenuta entro i rispettivi limiti ambientali (50 ppm per N2O e 0,5 ppm per isofluorano). Soltanto al primo controllo gli anestesisti hanno presentato un’esposizione a N2O significativamente più alta di quella dei chirurghi/strumentisti. L’indagine ha evidenziato che: i dati del campionamento in posizione fissa, se analizzati tenendo conto dei periodi di presenza dei lavoratori in sala, possono essere utilizzati per stimare l’esposizione individuale; l’esposizione diminuisce dopo i controlli in seguito all’applicazione di misure preventive; la ripetizione dei controlli risulta necessaria perché l’esposizione supera spesso i valori limite; il gradiente espositivo tra le diverse figure professionali scompare quando diminuisce l’inquinamento in zona anestesista
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“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
Get PDFWe 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
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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