Effects of contemporary orthodontic composites on tooth color following short-term fixed orthodontic treatment: A controlled clinical study

Background/aim: To determine the color alterations of natural teeth associated with different orthodontic composites used in comprehensive short-term treatment. Materials and methods: Twenty-two patients were treated with fixed appliances and 22 untreated subjects were also evaluated. Lower incisors were bonded with different orthodontic composites: 42 with Grengloo, 41 with Light Bond, 31 with Kurasper F, and 32 with Transbond XT. The color parameters of the Commission Internationale de l’Eclairage (CIE) were measured for each tooth with a spectrophotometer. Color assessment in relation to time, adhesive material, and their interaction was made with 2-way mixed analysis of variance (ANOVA) and 1-way ANOVA for the color differences (ΔE*). Further analyses were done using Tukey’s honestly significant difference tests and paired-samples t-tests. Results: The color of teeth was affected by treatment. The mean L* and a* values increased, whereas the mean b* values decreased. Total color differences of teeth demonstrated visible color changes clinically after treatment, ranging from 1.12 to 3.34 ΔE units. However, there were no significant differences for color of enamel. Conclusion: Teeth may be discolored with fixed appliances during treatment. Moreover, contemporary orthodontic composites have similar effects of enamel discoloration. © TÜBİTAK

On Almost Alpha Kenmotsu (k,u)-Spaces

In this paper, the geometry of almost alpha Kenmotsu (k,u)-spaces are studied. Finally, we give an illustrative example on almost alpha Kenmotsu (k,u)-space of dimension

The Case for Improving the Robinson Formulas

Auroral particle precipitation is the main source of ionization on the nightside, making it a critical factor in geospace physics. This magnetosphere‐ionosphere linkage directly contributes to, even controls, the nonlinear feedback within this coupled system. One study has dominated our understanding of this connection, presenting a pair of equations relating auroral particle precipitation to ionospheric Pedersen and Hall conductance, the famous Robinson formulas. This Commentary examines the history of the development and usage of the Robinson formulas and the recent studies exploring corrections and expansions to it. The conclusion is that more work needs to be done; the space physics research community should take up the task to develop improvements and enhancements to better quantify the connection of auroral precipitation to ionospheric conductance.Key PointsThe development and usage of the famous Robinson formulas, relating auroral precipitation to ionospheric conductance, is recountedRecent approaches to address shortcomings of these formulas are reviewed and discussed, noting shortcomings in some of these studiesThe space physics research community is urged to take on the action of improving the connection between precipitation and conductancePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/163473/2/jgra56025.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/163473/1/jgra56025_am.pd

Analysis of Yield Criteria and Flow Curves on FLC for TWIP900 Steel

In this study, the applicability of yield criteria and flow curve models to predict forming limit curve (FLC) via the Marciniak-Kuczynski (M-K) model is investigated for TWIP900 steel. Forming limit characteristics of TWIP900 are determined experimentally and numerically. The yield criteria of Hill48, Barlat89, YLD2000-2d, and BBC2000 are tested and compared with each other. Results indicate that the YLD2000-2d and the BBC2000 yield criteria are found to be more accurate than the other criteria. The YLD2000 criterion has the best prediction capability with the Krupskowsky flow curve while the BBC2000 model has the best prediction with the Ludwick flow curve model. © 2020, The Society for Experimental Mechanics, Inc

Heavy metal accumulation in Artemisia and foliaceous lichen species from the Azerbaijan flora

Artemisia plants and foliaceous lichens are known to be capable of accumulating heavy metals (HM) from soil and air. These plant species are widespread on polluted sites of Azerbaijan. However, so far their capacity to accumulate HM in their shoots and roots has not been tested. Three Artemisia and two lichen species were collected from different contaminated sites of Azerbaijan. Plant and surface soil samples were measured for Cd, Cu, Pb, Ni and Zn concentrations by ICP-AES.The results indicated that among the Artemisia species A. scoparia showed the best HM accumulation properties. Lichen species were also distinguished by very high amounts of HM in their biomass, while in surrounding soil samples HM concentrations had higher contents than the soils occupied only with Artemisia species.The results indicate that on contaminated sites Artemisia and lichens accumulated metals in their biomass without toxicity symptoms. Taking large biomass and high adaptation ability into account, A. scoparia represents a good tool for a phytoremediation approach on polluted soils

Notes on the thermal habitat: Thirteen new records for the freshwater algal flora of Turkey

1661-1668Thermal springs are extreme environments for organisms. Cyanobacteria are the group that adapts with success in these environments where there is little diversity of life. In this study, eight different thermal water springs were studied in Kütahya province. Thirteen cyanobacteria taxa were identified as new records for the freshwater algal flora of Turkey. Some morphological and taxonomical characteristics of the taxa were briefly described in this paper, with original photos

Traumatic abdominal wall hernias: disruptions of the abdominal wall muscles associated to pelvic bone fractures illustrated by two case reports.

Blunt abdominal traumas are often associated with intra-abdominal injuries and pelvic fractures. Traumatic abdominal wall hernias due to disruption of the abdominal wall muscles may be overlooked. Delayed diagnosis can lead to hernia related complications. We present two cases of high kinetic trauma with pelvic fractures and acute traumatic abdominal wall herniation. Both of these cases suffered from a delayed diagnosis and needed surgery to treat the symptomatic herniation. Clinical reassessment and appropriate medical imaging are mandatory in patients with high kinetic abdominal blunt traumas and associated pelvic fracture, in order to prevent delayed diagnosis and possible complications

Multidetector computed tomography findings of an asymptomatic levoatrial cardinal vein with an interatrial course

A 57-year-old female patient with a family history of coronary artery diseaseadmitted to our hospital for the coronary check-up. A coronary angiographywas performed with ECG-gated 128 slice dual source computed tomography.Multidetector computed tomography (MDCT) showed, in addition to the normalcoronary arteries, a persistent levoatrial cardinal vein (LCV) draining into vena cavasuperior. ECG-gated cardiac MDCT is a useful tool showing the origin, course, anddrainage site of LCV

Brieskorn manifolds as contact branched covers of spheres

We show that Brieskorn manifolds with their standard contact structures are contact branched coverings of spheres. This covering maps a contact open book decomposition of the Brieskorn manifold onto a Milnor open book of the sphere.Comment: 8 pages, 1 figur