Worn particulate titanium abraded from a titanium dental implant that discolors the adjacent soft tissues has not previously been reported. Two cases of this gingival tissue "tattooing" are reported ...here. While the use of zirconia abutments in areas of high esthetic concern is widespread, the effects of particulate titanium being worn from the implant by the much harder abutment material and then taken up in the adjacent soft tissues should be considered as a potential complication and a consideration when selecting the type of abutment to be used.
The purpose of this study was to use a clinical simulation to determine whether wear of the internal surface of a titanium implant was greater following connection and loading of a one-piece zirconia ...implant abutment or a titanium implant abutment.
Two implants received zirconia abutments and two received titanium abutments. The implants were secured into four fiber-reinforced epoxy resin disks that had been prepared to receive the internal-connection implants. The assemblies were cyclically loaded off-axis for a total of 1,000,000 cycles. At various intervals, the abutments were removed, photographed, examined using scanning electron microscopy (SEM), and returned to the implants for further testing. The area of titanium transfer from the implants to the abutments observed in the SEM images was quantified using image analysis software.
The method was able to quantify the area of material transferred to the abutments. There was considerably more wear associated with the zirconia abutments, but the rate of wear slowed after about 250,000 cycles. Parabolic curves were fit to the data. The projected mean ± standard deviation maximum area (wear) values associated with the titanium and zirconia abutments were 15.8 ± 3.3 x 10³ Μm² and 131.8 ± 14.5 x 10³ Μm², respectively, and this difference was statistically significant (P = .0081).
The implants with the zirconia abutments showed a greater initial rate of wear and more total wear than the implants with the titanium abutments following cyclic loading. The amount of titanium transfer seen on the zirconia abutment increased with the number of loading cycles but appeared to be self-limiting. The clinical ramifications of this finding are unknown at this time; however, the potential for component loosening and subsequent fracture and/or the release of particulate titanium debris may be of concern.
In this study the leaching of a one component (1K) structural epoxy model adhesive for the automotive industry is analysed via fourier transform infrared spectroscopy (FT-IR). In addition, the ...gravimetric water uptake and morphological changes were observed.
Findings indicate a two-stage water absorption at room temperature, whereas at 70 °C the water absorption shows a drastically increased value including a loss of mass after 500 h of immersion in DI-water. Water content at ambient conditions shows a dependency of the absolute humidity. FT-IR analyses of the dried eluate originating from immersion at 23 °C reveals typical bands of the latent hardener dicyandiamide and the filler CaCO3. On the other hand, the spectrum of the eluate originating from immersion at 70 °C exhibits bands of the fumed silica used as rheological additive. Microscopical observation by means of scanning electron microscopy (SEM) of the adhesive reveals that cavities arise in the vicinity of the inorganic particles contained in the adhesive due to water uptake.
•A novel, near to realism structural epoxy adhesive for scientific purposes.•Gravimetric water uptake in structural epoxy adhesive.•Leaching of substances.•Morphological changes upon water uptake.
The present volume is a collection of thirteen papers resulting from a sympo-sium on the computer-aided production and publication of dictionaries held in Heidelberg in 1988 (p. 4). It is subdivided ...into two sections, Basics (Grundlagen), which discusses the impact of computational methods on lexicography in gen-eral, and Applications (Anwendungen), which contains descriptions of various existing computer-aided lexicographical projects. All of these projects deal with German as the object of lexicographical description and many of them are con-cerned with specialized scholarly dictionaries, often of historical stages of Ger-man. Thus two articles (Burch and Fournier; Plate and Recker) deal with Mid-dle High German and another one (Gloning and Welter) with the language of Goethe. Some articles, however, also describe projects dealing with present-day German and the design of general purpose dictionaries. Thus Petelenz dis-cusses information design in an electronic Polish–German dictionary and Haß-Zumkehr focuses on the organisation of the microstructure in the LEKSIS-data-base of the Institut für Deutsche Sprache in Mannheim.
Innovation as a response strategy to a crisis needs further understanding for small enterprises. This exploratory research investigates if, why, and with whom entrepreneurs in micro and small ...enterprises engage in innovation activities during the atypical context of the COVID-19 crisis in the tourism sector. The multiple case study with three German entrepreneurs in the tour operator market shows that micro and small enterprises despite their size hold the capacity to initiate and manage several innovation projects of different types and in different stages of the innovation value chain simultaneously during a crisis. To do so, the entrepreneurs preferably engage participants with strong social ties, independent from a place. The perceived benefits are both related to the innovation output (e.g. generate income), and the innovation activities (e.g. increased motivation of staff, increased trust of customers during the crisis). Further research is encouraged on the long-term effects of innovations resulting from a crisis.
With respect to verb complementation, a grammaticalist and lexicalist approach can be distinguished. While the grammaticalist position appears to be more attractive, it must deal with the problem of ...exceptions, where verbs do not occur in certain patterns although they are semantically compatible. One example for this is the blocking of the ditransitive pattern with verbs such as explain and say. This paper will discuss the historical syntactic development of these two verbs in order to understand how the blocking came about. Data from the OED and various historical corpora will be used. It will be argued that while the findings are more compatible with the lexicalist view on verb complementation, ultimately an approach will be needed which reconciles both approaches.
The coxsackie and adenovirus receptor (CAR) plays a role in viral infection, maintenance of the junction adhesion complex in polarized epithelia, and modulation of cellular growth properties. As a ...viral receptor, the C-terminus appears to play no role indicating that the major function of CAR is to tether the virus to the cell. By contrast, the C-terminus is known to play a role in cellular localization and probably has a significant function in CAR-mediated adhesion and cell growth properties. We hypothesized that the CAR PDZ (PSD-95/Disc-large/ZO-1) binding motif interacts with PDZ-domain-containing proteins to modulate the cellular phenotype. CAR was modified by deleting the last four amino acids (CARDeltaGSIV) and evaluated for cell-cell adhesion in polarized primary human airway epithelia and growth characteristics in stably transfected L-cells. Although ablation of the CAR PDZ-binding motif did not affect adenoviral infection, it did have a significant effect both on cell-cell adhesion and on cell growth. Expression of CARDeltaGSIV failed to increase the transepithelial resistance in polarized epithelia to the same degree as wild-type CAR and failed to act as a growth modulator in L-cells. Furthermore, we provide evidence for three new CAR interacting partners, including MAGI-1b, PICK1 and PSD-95. CAR appears to interact with several distinct PDZ-domain-containing proteins and may exert its biological function through these interactions.
Background: Recurrence in cerebral palsy (CP) patients who have undergone operative or non-operative correction varies greatly from one study to another. Therefore, we conducted this meta-analysis to ...determine the pooled rate of equinus recurrence following its correction either surgically or non-surgically. Methods: Nine electronic databases were searched from inception to 6 May 2021, and the search was updated on 13 August 2021. We included all studies that reported the recurrence rate of equinus following its correction among CP patients. The primary outcome was recurrence, where data were reported as a pooled event (PE) rate and its corresponding 95% confidence interval (CI). We used the Cochrane’s risk of bias (RoB-II) tool and ROBINS-I tool to assess the quality of included randomized and non-randomized trials, respectively. We conducted subgroup analyses to identify the sources of heterogeneity. Results: The overall rate of recurrence was 0.15 (95% CI: 0.05−0.18; I2 = 88%; p < 0.01). Subgroup analyses indicated that the laterality of CP, study design, and intervention type were significant contributors to heterogeneity. The recurrence rate of equinus differed among interventions; it was highest in the multilevel surgery group (PE = 0.27; 95% CI: 0.19−0.38) and lowest in the Ilizarov procedure group (PE = 0.10; 95% CI: 0.04−0.24). Twelve studies had a low risk of bias, eight had a moderate risk, and nine had a serious risk of bias. Conclusion: The recurrence of equinus following its correction, either surgically or non-surgically, in CP patients is notably high. However, due to the poor quality of available evidence, our findings should be interpreted with caution. Future studies are still warranted to determine the actual risk of equinus recurrence in CP.
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