1,720,976 research outputs found
Microemulsions: The Renaissance of Ferrite Nanoparticle Synthesis
No full textFerrite nanoparticles (NPs) are of special interest for a wide range of applications. Microemulsions represent the Renaissance of ferrite NP preparation offering a series of advantages with respect to other methods due the possibility to confine reactions into nanosized reactors. They allow the preparation in mild synthesis conditions of a wide variety of nanostructured ferrites with controlled composition, particle size and shape. This review wants to give a comprehensive overview of the microemulsion performance in the ferrite NP synthesis. Firstly, a general section on microemulsion properties is presented. The basics of NP formation mechanism, with a first-rate emphasis in the influence of microemulsion properties and dynamics on the control of NP size and shape, are addressed. A summary of the synthesis procedure evolution by both direct and reverse microemulsions over a selection of ferrite NPs is also provided in the review. Finally, the perspectives on microemulsion systems for ferrite NP preparation are quickly revised
[Dysplastic cysts of the liver: our experience].
No full textAIM: Systematic surveys with advanced non-invasive imaging techniques have
revealed that hepatic cysts are quite common in the general population.
Therefore, we retrospectively examined our case series and compared it with the
literature.
METHODS: Between January 1990 and December 2000, 228 patients with non-parasitic
liver cysts were referred to the outpatients section of the Department of Surgery
of the University of Cagliari and 23 were submitted to treatment: 14 patients
(60.8%) for solitary cyst and 9 (39.2%) for multiple simple cysts of the liver.
One patient (4.5%) had right upper quadrant pain. Eleven (47.8%) patients were
asymptomatic: 7 (63.7%) required treatment for other pathologies, 3 (27.3%) for a
progressive enlargement of the cyst and 1 (9%) for a suspected hydatid disease.
Mean diameter of the treated cysts measured by preoperative CT or US was 8.8 cm
(range 7-14). Percutaneous aspiration-injection reaspiration (PAIR) was performed
in 5 patients (21.7%), US-guided in 2 cases (40%) and CT-guided in 3 (60%).
Twenty patients (86.9%) underwent cysts unroofing, 18 (78.2%) with open surgical
fenestration and the latest 2 cases with a laparoscopic approach. Two patients
had PAIR as second treatment for recurrence: CT-guided in one and US-guided in
the other case.
RESULTS: Four (25%) out of 16 patients treated exclusively for cystic liver
disease, had fever in 3 cases and nausea and vomiting in 1 case; 8 patients (50%)
had an intraperitoneal drainage for a mean of 6-7 days (range 4-11) and of 116 cc
of serum-hematic liquid.
CONCLUSIONS: In our opinion the choice of an adequate treatment must be based on
an accurate evaluation of the clinical aspects of the patients and on the
characteristics of cystic lesions such as number, size and location. These data
let us to choose a surgical treatment rather than a strict US follow-up and to
get the best outcome in terms of absence of recurrence, and less biological and
economic costs
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
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
Progetto pilota per la sensibilizzazione all'igiene delle mani di operatori, pazienti e visitatori
No full textAppropriate 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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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