Comparison of Gingival Retraction Materials Using a New Gingival Sulcus Model

Purpose To investigate the pressure generated by different retraction materials using a novel gingival sulcus model. Materials and Methods A gingival sulcus model was made using a polymer frame filled with silicon. A pressure sensor and a sulcus‐fluid simulation were embedded into the silicon chamber to evaluate the pressure generated by different retraction materials. Six sizes of Ultrapak retraction cords (Ultradent, sizes #000 ‐ 3), 4 retraction pastes (Expazen, Expasyl, Acteon, Access Edge, Traxodent) and 2 retraction gels (Sulcus Blue, Racegel) were analyzed. The mean and median pressure, interquartile range, and standard deviation (SD) of n = 10 repeated measurements were calculated. Statistical analysis was conducted by Kruskal‐Wallis test for differences between the main groups of retraction materials, and Mann‐Whitney U‐test was performed to analyze differences between the single retraction materials. Results Pressure (mean ± SD) generated by retraction cords increased with increasing size (48.26 ± 11.29 kPa, size #000 to 149.27 ± 28.75 kPa for #3). There was a significant difference between sizes (p \u3c 0.01), except in #0 versus #1, and #2 versus #3. Retraction pastes generated pressures that ranged from 82.74 ± 29.29 kPa (Traxodent) to 524.35 ± 113.88 kPa (Expasyl). Retraction gels generated pressures from 38.96 ± 14.68 kPa (Racegel) to 95.15 ± 24.18 kPa (Sulcus Blue). Pressure generated by Expasyl was significantly higher than pressure generated by all other tested materials (p \u3c 0.001). Conclusion Pressure generated by retraction pastes and gels depends on the consistency of the retraction material, while pressure generated by retraction cords increased with increasing size of cords. Expasyl was found to generate the highest pressure compared to all other retraction materials

R-esp1, a rat homologue of Drosophila Groucho, is differentially expressed after optic nerve crush and mediates NGF-induced survival of PC12 cells

AbstractThe differential display reverse transcription polymerase chain reaction method was used to detect alterations in gene expression in the superior colliculus after optic nerve crush in adult rats. One of the most prominent changes observed was the selective induction of R-esp1, a homologue of the Drosophila enhancer of split locus (Groucho). Therefore, we studied the influence of R-esp1 on nerve growth factor (NGF)-induced cell survival of PC12 cells. Overexpression of R-esp1 promotes cell survival even in the absence of NGF and, conversely, it is reduced by antisense-mediated inhibition of R-esp1 expression. In conclusion, we propose a novel model in which R-esp1 protein mediates the NGF-signaling pathway

Laser-Microstructured Double-Sided Adhesive Tapes for Integration of a Disposable Biochip

Laser-microstructured double-sided biocompatible adhesive tapes as intermediated bonding layers are potential candidates for hybrid integration of a disposable biochip. In the EU-PHOCNOSIS project, such thin adhesive tapes are proposed to integrate the polymer microfluidic system with the optical sensor chip. Three laser-assisted structuring methods are investigated to efficiently transfer microchannel patterns to the adhesive tape at room temperature. The test structure design consists of a single channel with 400 µm wide, 30 mm length and two circular receivers with 2 mm radius. The best structuring results are found by using a UV picosecond laser.EC/H2020/634013/EU/Advanced nanophotonic point-of-care analysis device for fast and early diagnosis of cardiovascular diseases/PHOCNOSI

Development Of An Adaptive Augmented Reality Qualification System For Manual Assembly And Maintenance

The manufacturing industry is facing various challenges today - globalization, fast-moving sales markets, short product life cycles, individualization, mass production and diversity of variants are trends that will continue or even increase in the future. Speed and flexibility in production are thus becoming important success factors for companies. To meet the demands of the market, there is a growing necessity to deploy employees flexibly within the production process. This increases the need for additional qualification of workers. By overlaying reality with virtual cues, Head-mounted displays (HMD) can present information in a situation-specific and location-linked manner. Data glasses also offer a high and convertible degree of support through the possibility of providing different media forms while both hands are available at the same time. Augmented Reality (AR) guidance systems are already available on the market and are suitable as permanent assistance systems, but only to a limited extent for qualification aspects. An industrially applicable qualification software that collects expert knowledge from skilled workers and then makes it available to new or inexperienced employees in an adaptive way that promotes learning is currently not available. This paper therefore presents the development of the software AQUA, which taps internal expertise with low effort and creates training courses that convey learning content to learners without over- or under-challenging them

Resistive Switching Mechanisms on TaOx and SrRuO3 Thin-Film Surfaces Probed by Scanning Tunneling Microscopy

The local electronic properties of tantalum oxide (TaO[subscript x], 2 ≤ x ≤ 2.5) and strontium ruthenate (SrRuO[subscript 3]) thin-film surfaces were studied under the influence of electric fields induced by a scanning tunneling microscope (STM) tip. The switching between different redox states in both oxides is achieved without the need for physical electrical contact by controlling the magnitude and polarity of the applied voltage between the STM tip and the sample surface. We demonstrate for TaO[subscript x] films that two switching mechanisms operate. Reduced tantalum oxide shows resistive switching due to the formation of metallic Ta, but partial oxidation of the samples changes the switching mechanism to one mediated mainly by oxygen vacancies. For SrRuO[subscript 3], we found that the switching mechanism depends on the polarity of the applied voltage and involves formation, annihilation, and migration of oxygen vacancies. Although TaO[subscript x] and SrRuO[subscript 3] differ significantly in their electronic and structural properties, the resistive switching mechanisms could be elaborated based on STM measurements, proving the general capability of this method for studying resistive switching phenomena in different classes of transition metal oxides.National Science Foundation (U.S.). Materials Research Science and Engineering Centers (Program) (Grant DMR-1419807

Compositional and structural studies of ion-beam modified AlN/TiN multilayers

This work was supported the Serbian Ministry of Education, Science and Technological Development (project ON 171023), ERC Advanced Investigator grant (226470 SILAMPS), and the International Atomic Energy Agency, Vienna (CRP 12024). We thank Petro Parisse and Loredana Casalis of the NanoInnovation Laboratory of Elettra – Sincrotrone Trieste SCpA for the AFM measurements

QCD sum rules at finite density in the large-N_c limit: The coupling of the rho-nucleon system to the D_{13}(1520)

QCD sum rules are studied for the vector-isovector current at finite baryon density in the limit of large number of colors N_c. For the condensate side it is shown that in this limit the four-quark condensate factorizes also for the finite density case. At the hadronic side the medium dependence is expressed in terms of the current-nucleon forward scattering amplitude. Generalizing vector meson dominance we allow for a direct coupling of the current to the nucleon as well as a coupling via the rho meson. We discuss the N_c dependence of (a) modifications of the pion cloud of the rho meson, (b) mixing with other mesons (in particular a_1 and omega) and (c) resonance-hole excitations R N^{-1}. We show that only the last effect survives in the large-N_c limit. Saturating the sum rules with a simple hadronic ansatz which allows for the excitation of the D_{13}(1520) we determine the coupling of the latter to the rho-nucleon and the photon-nucleon system. These couplings are hard to determine from vacuum physics alone.Comment: 13 pages, 2 figure

π+\pi^+ photoproduction on the proton for photon energies from 0.725 to 2.875 GeV

Differential cross sections for the reaction $\gamma p \to n \pi^+$ have been measured with the CEBAF Large Acceptance Spectrometer (CLAS) and a tagged photon beam with energies from 0.725 to 2.875 GeV. Where available, the results obtained here compare well with previously published results for the reaction. Agreement with the SAID and MAID analyses is found below 1 GeV. The present set of cross sections has been incorporated into the SAID database, and exploratory fits have been made up to 2.7 GeV. Resonance couplings have been extracted and compared to previous determinations. With the addition of these cross sections to the world data set, significant changes have occurred in the high-energy behavior of the SAID cross-section predictions and amplitudes.Comment: 18 pages, 10 figure