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Pysico-mechanical charaterization of cementitious mortars for reparing damaged masonry structures.
No full textExperimental evaluation of a new haemostatic material.
No full textExperimental evaluation of a new haemostatic biomaterial
*Continenza M.A., **Pajewski L.A., °D'Ascoli R., **Vegliò F.
*Dip. Scienze Chirurgiche, **Dip. Chimica, Ing. Chimica e Materiali - Università degli Studi dell'Aquila, ° Baxter Manifacturing S.p.A, Rieti (I)
Introduction: The pharmacopoeia offers many local haemostatic agents to stop the bleeding and often for the surgeon is very hard to choice the better one. In this paper a comparison study was performed between four haemostatic biomaterials: a standard "first aid" cotton gauze, a gelatin sponge (Spongostan), a regenerated cellulose gauze (Tabotamp) and an haemostatic sponge newly synthesized (Matemo).
Materials and methods: To obtain objective data, two parameters were measured: the Bleeding Time (BT - s), and the Blood Absorbing Rate (BAR - mg/s); both measures were collected in vivo by a rat model with or without heparin pre-treatment. As fixed in the protocol, the ventral wall of each anesthetized animal was shaved, the skin was incised and in the subcutaneous tissue three veins different in size (small, medium and big vein) were selected and cut, applying the cotton gauze on the left side and on the right side the other new biomaterial, in parallel. At the end of this phase, the abdominal wall was open and two lobe of the liver was injured to test the haemostasis time in the organ bleeding. The BT was measured as the time passing from the vein or organ incision till the stop of bleeding due to the application on the site of one of the selected agents. The Blood Mass lost (BM) was determined by weighting all the pre-weighted haemostatic samples, recovered from the injury after the haemostasis, and for each haemostatic agent, was calculated the BAR rate, dividing the obtained BM by the BT value. The BAR value was considered the most important parameter in this experiment, because of it express the capability of each biomaterial to absorb the blood from the hemorrhage site, and consequently, the performance of maintaining very clean the operation field.
To statistically evaluate the data, a factorial model was carried out, repeating four times the experiment for each biomaterial.
Results: This experimental protocol produced very interesting results. The new haemostatic sponge Metemo revealed the best performance as when compared with Spongostan as when compared with Tabotamp, in normal and in the heparinized animals. With Matemo sponges, the bleeding time significantly decreased and the blood absorption was the fastest between the four selected haemostatic agents, maintaining the operation field very clean. Obviously, the faster hemostasis determined the least BM loss, revealing in this way the better haemostatic function in order to the animal survival and to the surgeon demands. Further experiments are developing to verify the in vivo biodegradation of this new haemostatic agent Matemo
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
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