1,720,992 research outputs found
Esthetic and physical changes of innovative titanium surface properties obtained with laser technology
No full textAim: The purpose of the study was the evaluation of the esthetic and physical changes produced on colored titanium Grade 5 (Ti6Al4V) laser treated surfaces to be used in implant dentistry for esthetic success. Materials and methods: Colored titanium surfaces were obtained with laser treatment. The physical and topographic properties were evaluated by stereo, light, and electron microscopy and profilometric analyses. L*a*b* colorimetric coordinates were measured by spectrometry, and the superficial chemical characteristics were evaluated by energy dispersive X-ray analysis. Results: Within the complete palette of titanium colors, pinks (P1-P2), incarnadine (I), and white (W) obtained by laser were selected. The topography, texture, hues, saturation, roughness, and porosity of the samples were compared with those of machined (M) and sand-blasted and etched (SBAE) control surfaces. P1, P2, and I, similar in hue and roughness (Ra ≅ 0.5 μm), had a microgroove spacing of 56 μm and a decreasing porosity. The W sample with a "checkerboard" texture and a light color (L* 96.31) was similar to the M samples (Ra = 0.32 μm), but different from SBAE (Ra = 1.41 μm, L* 65.47). Discussion: The aspects of hard and soft tissue could result in an esthetic failure of the dental implant by showing the dark color of the fixture or abutment. The two different pinks and incarnadine surfaces showed favorable esthetic and physical features to promote dental implant success even in the maxillary anterior area with gingival recession, asymmetry, and deficiency. Conclusion: Titanium colored laser surfaces represent a valid alternative to those currently traditionally obtained and interesting and potential perspectives in the management of dental implants' esthetic failure
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
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
Effects of novel laser dental implant microtopography on human osteoblast proliferation and bone deposition
No full textPurpose: The aim of this study was to compare how two innovative laser titanium surfaces and sandblasted and acid-etched surfaces inflfluence human osteoblast behavior during osteogenesis and the initial phases of bone deposition. Materials and Methods: Human osteoblasts from human adipose stem cells were sorted by flow cytometric analysis and induced to differentiate. After 40 days, the osteogenic differentiation was detected by alizarin red staining, and the alkaline phosphatase (ALP) was evaluated with western blot (WB) and real-time reverse transcriptase-polymerase chain reaction (RT-PcR) analysis. After confluence, human osteoblasts were cultured onto two different innovative laser-obtained titanium surfaces (L1 and L2) and compared with one sandblasted and acid-etched (SBAE) surface as the control. At different times, human osteoblast behavior was evaluated with cell proliferation viability assay (MTT), scanning electron microscopy (SEM), energy-dispersive x-rays (EDAX), osteogenic markers with RT-PcR, and WB analysis of matrix extracellular phosphoglycoprotein (MEPE), ALP, and osteocalcin (OCN). Results: After cell sorting, the human osteoblasts from human adipose stem cells showed increasing values of ALP mRNA and protein expression. The osteogenic differentiation was confirmed by quantitative alizarin red staining assay. Profilometric and SEM analysis showed relevant differences between SBAE, L1, and L2 specimens. After 20 days of culture onto titanium samples, SEM evaluation showed a small number of human osteoblasts and isolated sites of bone matrix deposition in SBAE specimens. At the same time, on L1 surfaces, only an osteoblast mono-layer with initial bone deposition was found, while on L2 specimens, there was a thick network with flattened large stellate cells, many cellular interconnections with strong titanium adhesion, and a large complex mineralized structure of crystal bone. After 20 days, for all titanium samples, human osteoblasts culturing EDAX analysis showed the absence of impurities and a higher bone matrix deposition in L2 specimens compared with L1 and SBAE samples. Conclusion: The innovative microtopography and nanotopography laser-induced surface showed high biocompatibility with primary human osteoblast cultures and the absence of impurities. The innovative laser texture was capable of influencing the osteogenic process, confirming the critical role of titanium surface characteristics in the cell adhesion and bone deposition during the early phases of osseointegration. The association of human adipose stem cells and titanium surfaces laser-induced with an innovative procedure could generate promising improvements and developments in orthopedics, maxillofacial, and dental implant surgery
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
Identification, characterization and weathering of the stones used in medieval religious architecture in L’Aquila (Italy)
No full textIn the city of L’Aquila the historical and artistic significance and the density of
religious buildings is notable. From the 11th to the 19th century the ornamental stones quarried
in the surroundings of L’Aquila have been used for religious architecture, civil artefacts
and buildings of great artistic and historical relevance. Great emphasis has been placed on
the recognition of ancient quarries where these ornamental stones were carved. In this paper
the petrographical, physical, mechanical and technological characteristics of the limestones
and marly limestones sampled in the quarries are reported. The main characteristics will be
discussed and correlated to the decay forms, with the aim of achieving a general strategic
approach based on a diagnostic phase and an application phase
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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