103,265 research outputs found
Study of unmyelinated fibers in patients with primary Raynaud's phenomenon and secondary to systemic sclerosis disease
No full textIn-vitro comparison of toothbrush bristles penetration into the peri-implant sulcus
No full textBackground: Implant-prosthetic reconstructions present anatomical and structural characteristics different from the dento-periodontal condition. These differences can lead to a problematic hygienic access by toothbrush bristles and a consequently reduced biofilm removal.
Aim/Hypothesis: The aim of this preclinical study was to compare the ability of the conical and cylindrical bristles to penetrate the peri-implant sulcus.
Material and Methods: A mandibular dentition was reproduced using a plaster model: the gingival component was recreated in silicone and a glass cylinder was positioned simulating a 4 mm diameter implant. The penetration of the bristles during brushing was recorded by using an optical fiber placed inside the cylinder. The Bass Technique was performed in a humid environment from the vestibular side. This brushing motion is described as a vibratory movement of the bristles oriented at 45° respect to the long axis of the tooth into the sulcus. The protocol included 5 toothbrushes per group and 10 tests per toothbrush, for a total of 50 assessments for each of the two groups. Each test lasted 1 minute with controlled pressure of approximately 350gr and a stroke length of 25 mm. Five degrees of penetration were identified: grade 0 (<2 mm), grade 1 (2–3 mm), grade 2 (3–4 mm), grade 3 (4–5 mm) and grade 4 (5–8 mm). The highest value was collected for each test.
Results: The conical bristles showed 8 times greater efficacy (P = 0.001) than the cylindrical bristles (multilevel analysis). The percentage of tests reaching depths ≥3 mm was 86% for conical group and 28% for the cylindrical group.
Conclusion and Clinical implications: This preclinical study shows a clear and superior penetration capacity of the conical bristles compared to traditional cylindrical ones. Further studies are required to investigate the correlation between penetrative capacity and cleaning efficacy in implant conditions. If a greater penetrative capacity is correlated with a greater cleaning efficacy, then these newly designed bristles would be preferable
The role of stereoelectronic effects on the side-chain fragmentation of alkylaromatic radical cations. The reactivity of 5-methoxy-2,2-dimethylindan-1-ol radical cation
No full textA kinetic and products study of the reaction of 2,2-dimethyl-5-methoxyindan-1-ol (1) radical cation, in acidic aqueous solution (pHless than or equal to4) has been carried out. 1(.+) undergoes C-H deprotonation as the exclusive reaction with k=4.6x10(4) s(-1). The kinetic data have been compared with those obtained for the radical cations of 1-(4-methoxyphenyl)ethanol (2) and 1-(4-methoxyphenyl)-2,2-dimethyl-1-propanol (3), suggesting that the deprotonation rate increases when the C-H bond is forced into a conformation where it is almost aligned with the pi-system. The conclusion that overlap between the scissile bond and the pi-system is an important requisite for the occurrence of bond cleavage is also supported by the results of DFT calculations carried out for 1(.+) and 3(.+). (C) 2002 Elsevier Science Ltd. All rights reserved
Advances in cultural heritage studies
No full textThe announcement of the creation of a European Year of Cultural Heritage (year 2018) by the Decision 2017/864 of the European Parliament – encouraged the creation, in 2017, of the European Students’ Association for Cultural Heritage (ESACH) ESACH has become the first still-growing interdisciplinary and cross-generational network in the field. Currently brings together young researchers and researchers at early stages of their careers, in the fields of culture and heritage, from all kinds of academic disciplines and is made up of members from various European universities and research centres (see www.esach.org).
Within the network, the main questions are: How do we engage with the past elements of our culture(s)? How and why do we protect culture as a genuine element of a contemporary cultural system? What do younger generations state as heritage and what ways do they see to safeguard and experience it? ESACH stands up for a participatory way of involvement and is eager to take part in the cultural discourse at European and national levels.
Since ESACHS’ foundation, the Portuguese publisher Mazu Press (www.mazupress.com) has been associated with the initiatives of the Portuguese branch of ESACH based in Lisbon (Sharing Heritage Lisbon), firstly with the promotion actions and then with the publication of the book “New Perspectives in Interdisciplinary Cultural Heritage Studies. Contributions of the European Students’ Association for Cultural Heritage in the European Year of Cultural Heritage 2018”.
In this atypical Covid-19 pandemic year, Mazu Press again invited ESACH to join the renewed idea of “unifying through Cultural Heritage”, creating the opportunity for all to associate their efforts to this volume of “Advances in Cultural Heritage Studies, Year 2020”. Until now, ESACH members have been given the opportunity to contribute their ideas in several European events organized by the respective stakeholders, such as the Genoa Meeting, in October 2019, which had the cultural, logistic and financial support of the University of Genoa and foremost the PhD Course in Study and Enhancement of the Historical, Artistic-Architectural and Environmental Heritage. This book brings together twenty chapters by twenty four authors from Canada, Greece, Ireland, Italy, Poland, Portugal, Slovakia, Spain and Turkey. This sharing of knowledge, culture and heritage studies, through various disciplines, shows the richness – advances and new perspectives – generated by the common passion for cultural heritage
In vitro comparison of two types of toothbrush bristles in penetration capacity into the peri- implant sulcus.
No full textAim: The aim of this preclinical study was to compare the ability of the conical and cylindrical bristles to penetrate the peri-implant sulcus.
Methods: A mandibular dentition was reproduced using a plaster model. The gingival component was recreated in silicone and a glass cylinder simulating a 4mm diameter implant was positioned by replacing element # 3.6. Using an 1mm diameter optical fiber placed from the lingual side inside the cylinder, the penetration of the bristles was recorded during the brushing. The Bass Technique was performed in a humid environment from the vestibular side. This brushing motion is described as a vibratory movement of the bristles arranged at 45° respect to the long axis of the tooth into the sulcus. The protocol included 5 toothbrushes per group and 10 tests per toothbrush for a total of 50 assessments per group. Each test lasted 1 minute with controlled pressure of approximately 500gr and a stroke length of 15 mm. From the video clips acquired, 4 degrees of penetration were identified: grade 0 (<2mm), grade 1 (2-3mm), grade 2 (3-4mm), grade 3 (4-5mm) and grade 4 (5-8mm). The highest value was collected for each test. At an α level of 0.05 for a one-tailed test with a power of 80% and a margin of superiority of 40%, a sample of 10 toothbrushes was needed. Intraoperative variability was assessed with the Cohen's kappa coefficient. A generalized mixed-effect linear model (multilevel analysis) was used considering the level of bristle penetration as the primary outcome and the type of bristle as fixed effects. The level of significance α was a priori set at 0.05. The null hypothesis affirms that no difference of efficacy (level of penetration) exists between the two types of bristles.
Results: Excellent agreement was obtained between the measurement performed by the examiner (K-statistics =1). The conical bristles showed 8 times greater efficacy (p = 0.001) than the cylindrical bristles; moreover, with respect to the latter, the degree of penetration of the conical bristles proved to be 2 times (p = 0.015), 20 times (p = 0.001) and 76 times (p = 0.001) higher than degrees 1, 2 and 3 respectively. The null hypothesis was therefore rejected.
Conclusion: This preclinical study shows a clear and superior penetration capacity of the conical bristles compared to traditional cylindrical ones. This result suggests a greater hygienic efficacy at the peri- implant level for the newly designed bristles
Serious Games and Archaeology: Rough Notes on Crafting Archaeological Data for Heritage Enhancement
No full textIn the last years, video games have proven to have a clear potential to support the experiencing of cultural heritage by the large public, complementing the current tools and practices based on tangible goods such as museums, exhibitions, archaeological sites. Serious games (SGs) – videogames designed for educational objectives – appear as a new tool to learn cultural content in an engaging way, to attract new publics and to enhance knowledge, awareness, and cultural tourism. This paper will provide a portrait of the current proposition of serious games in the archaeological sector in Italy, highlighting the educational objectives of serious games in this domain, and analysing the potentials of this tool. Later, an ongoing project concerning the presentation of the Poggio Imperiale Park in Poggibonsi (Siena, Tuscany) will be illustrated to underline how and why the design of a serious game for this specific site is to be considered as the last fragment of a very long and precise project aiming at enforcing a multi-level public outreach and heritage enhancement strategy
In-vitro comparison of two different toothbrush bristles about peri-implant sulcus penetration
No full textObjective: The aim of this preclinical study was to compare the ability of tapered and cylindrical bristles to penetrate the peri-implant sulcus. Methods: A full mandibular dental arch was reproduced in plaster cast. In site #3.6 a hollow glass cylinder was positioned simulating a 4 mm diameter implant and the gingival component was recreated by using dedicated silicone. A Bass brushing technique was performed from the vestibular side in humid environment. During it, the penetration of the bristles between the gum and the implant was recorded by mean of an optic fibre fixed inside the cylinder. The protocol included 5 toothbrushes per group and 10 tests per toothbrush, for a total of 50 assessments for each of the two groups. A scale of 5 grades for bristle penetration was defined: grade 0 (× < 2 mm), grade 1 (2 ≤ × < 3 mm), grade 2 (3 ≤ × < 4 mm), grade 3 (4 ≤ × < 5 mm) and grade 4 (5 ≤ × < 8 mm). From the video recordings the highest value of penetration was identified for each test. Results: The tapered bristles showed an 8 times greater penetration capacity (p = 0.001) in respect to the cylindrical bristles (multilevel analysis). The percentage of tests reaching depths ≥3 mm was 86% for tapered group and 28% for the cylindrical group. Conclusion: This preclinical study shows a clear and superior penetration capacity of the tapered bristles in respect to traditional cylindrical ones. For tapered bristles, a potentially greater hygienic efficacy around dental implants is suggested
High dynamic control of a stepper motor for textile applications
No full textTextile applications require peculiar specifications in terms of accuracy and speed from drives. In this paper a high dynamic control for a linear drive was realized. A vector control for a magnetic disc stepper motor was realized that allows huge linear acceleration and accurate speed control
Pre- and postoperative prostate specific antigen serum levels in clinically intracapsular prostatic cancer: Preliminary results
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