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Effect of nano-structured alumina coating on the bond strength of resin-bonded fixed dental prostheses in “in vitro” and “in vivo” conditions
No full textUvod: Peskanje je klinično uveljavljen pripravljalni postopek inertne cirkonijeve-oksidne površine, vendar pogosto ne nudi zadostnega oprijema keramike ter lahko poškoduje material, kar lahko zmanjša dolgoročno uspešnost cirkonijevih-oksidnih protetičnih sider. Nano strukturiran nanos aluminijevega oksida (NAC) predstavlja alternativen neinvaziven pripravljalni postopek cirkonijeve-oksidne površine pred cementiranjem.
Namen: Namen raziskovalnega dela je bil preučiti vpliv priprave cirkonijeve-oksidne površine z NAC na oprijem cementa in ga primerjati z ustaljenim kliničnim protokolom peskanja v “in vitro” in “in vivo” eksperimentalnih pogojih.
Metode: “in vitro” smo učinkovitost NAC preverili z merjenjem porušitve cementne vezi med cirkonijevimi-oksidnimi adhezijskimi mostovi in nosilnimi zobmi. Površini lepljenja smo pripravili s peskanjem ali NAC. Polovico vzorcev smo pred preizkušanjem hranili 150 dni v vodi in nato termomehansko utrujali (37.500 ciklov v termociklični napravi1.2×106 ciklov ciklične obremenitve med 5-50 N). “In vivo” smo učinkovitost NAC preverili v prospektivni, randomizirani, kontrolirani klinični študiji s primerjanjem preživetja adhezijskih mostov pripravljenih s peskanjem in z NAC. Vpliv različnih postopkov žganja keramike v zobotehničnem laboratoriju na učinkovitost NAC smo preverili s strižnim preizkusom, kjer smo izmerili moč vezave med kompozitnim cementom in površino cirkonijevih-oksidnih diskov pripravljenih z NAC kalciniranim pod različnimi temperaturnimi pogoji.
Rezultati: Pred staranjem smo na adhezijskih mostovih pripravljenih z NAC izmerili značilno višjo silo porušitve (724,1 ±58,3 N) kot pri peskanih (564.4 ±30.6 N), medtem ko po staranju razlik v izmerjeni sili porušitve nismo zaznali (580-590 N). Stopnja preživetja z NAC pripravljenih adhezijskih mostov je bila 93,8 %, s peskanjem pripravljenih mostov pa 86,7 %. Statistično značilnih razlik med skupinami nismo zaznali (log-rank, P=.54). Različni pogoji kalcinacijskega žganja niso vplivali na morfologijo NAC, medtem ko se je z dvigom temperature in časom žganja moč oprijema povečevala, kristalna faza pa spreminjala.
Zaključki: NAC predstavlja enakovreden alternativen postopek peskanju. NAC cirkonijeve-oksidne površine ne poškoduje, zato je njegova uporaba še posebej utemeljena pri pripravi novejših, translucentnih generacij cirkonijeve-oksidne keramike, kjer je učinek peskanja še bolj škodljiv kot pri klasični 3Y-TZP keramiki.Background: Bonding to zirconia dental restorations often impairs long-term treatment outcomes. Nanostructured alumina coating (NAC) provides a promising pretreatment of the zirconia bonding surface. However, limited “in vitro” and “in vivo” evidence of NAC performance exists.
Purpose: The thesis aimed to study the effect of NAC on the resin-bond to zirconia surface and compare it to clinically established airborne-particle abrasion (APA) in “in vitro” and “in vivo” conditions.
Methods: For studying the effectiveness of NAC “in vitro”, the bonding performance of zirconia resin-bonded prostheses (RBFDPs) cemented on complementary zirconia incisors both pretreated with NAC or APA were compared after 150 days of water storage and thermomechanical aging (37.500 cycles, 5-55 〃50N/1.2×106 cycles) by measuring load-bearing capacity (LBC). For studying NAC “in vivo”, the clinical survivals of NAC and APA pretreated RBFDPs were compared in a prospective randomized, controlled clinical trial. For studying the influence of different ceramic firing procedures on the effectiveness of NAC “in vitro”, shear bond strength (SBS) of resin cement to zirconia discs pretreated with NAC calcinated under different firing procedures was measured.
Results: Before aging, the NAC pretreated RBFDPs provided superior mean LBC (724 ±58 N) to APA (564 ±31 N), while after aging, no differences were detected with the LBC approximately 590 N (P˃0.05). Survival rates of zirconia RBFDPs pretreated with NAC and APA were comparable (P˃0.05). Coupling the NAC calcination treatment with different firing protocols in a dental laboratory did not affect the NAC’s morphology, while it affected the crystal phase. SBS to NAC calcinated under high-temperature protocols provided the highest and clinically acceptable bond strengths (>20Mpa).
Conclusions: NAC and APA pretreated zirconia RBFDPs showed comparable bonding performance. Therefore, NAC could be regarded as a viable alternative pretreatment method not damaging the zirconia surface as opposed to APA
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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