This paper reports on the preparation of TiN x thin films by d.c. reactive magnetron sputtering. The coating thickness ranged from 1.7 to 4.2 Am and the nitrogen content varied between 0 and 55 at.%. X-Ray diffraction showed the development of the hexagonal a-Ti phase, with strong [002] orientation for low nitrogen contents, where the N atoms fit into octahedral sites in the Ti lattice as the amount of nitrogen is increased. For nitrogen contents of 20 and 30 at.%, the q-Ti 2 N phase appears with [200] orientation. With further increasing the nitrogen content, the y-TiN phase becomes dominant. The electrical resistivity of the different compositions reproduces this phase behavior. The hardness of the samples varied from approximately 8 GPa for pure titanium up to 27 GPa for a nitrogen content of 30 at.%, followed by a slight decrease at the highest contents. A similar increase of stresses with nitrogen is observed. Structure and composition with the consequent changes in crystalline phases and the lattice distortion were found to be crucial in the evolution of the mechanical properties.
Purpose: To evaluate the long-term efficacy and safety of iris-fixated foldable phakic intraocular lenses (pIOLs) for the management of myopia and astigmatism after 6-year follow-up. Setting: Ophthalmology Department, Hospital Braga, Portugal. Design: Retrospective cohort study. Methods: Patients included underwent iris-fixated foldable Artiflex pIOL implantation between January 2010 and December 2013. Follow-up evaluations were performed 6 months postoperatively and every 12 months until 72 months. Preoperative and follow-up data on uncorrected and corrected distance visual acuity (CDVA), manifest refraction, endothelial cell density (ECD), and anterior chamber depth (ACD) were analyzed. Results: A total of 177 eyes of 98 patients with a mean age of 32.33 ± 7.13 years were analyzed. There was a statistically significant improvement in CDVA from 0.09 ± 0.02 logMAR preoperatively to 0.04 ± 0.02 logMAR (P < .0001) at 6 years postoperatively. The spherical equivalent demonstrated a statistically significant improvement from −9.50 ± 2.93 diopters (D) to −0.41 ± 0.45 D at 6 years. At 72 months, the efficacy and safety indexes were 0.94 and 1.15, respectively. A mean loss of 31.77 cells/mm2 (1.19%) was observed each year until the sixth year. The overall mean ECD loss after correction for the physiological loss was 3.02% after 6 years. No correlations were observed between the mean ECD loss and the preoperative ACD. Conclusions: The Artiflex pIOL was a safe, effective, and a stable option to correct myopia. A mean ECD loss of 3.02% was observed over 6 years. No pIOL was explanted due to corneal decompensation.
The present paper reports the influence of growth conditions on the properties of TiN thin films deposited by rf reactive magnetron sputtering in the low-pressure range. The effects of rf power at the Ti target and the negative bias voltage at the substrate in the morphology, structure, electrical resistivity and colour of the samples were studied in detail. X-Ray diffraction results showed that the d-TiN phase (a ;0.430 nm) is detected in all the samples. The sample prepared with grounded substrate 0 revealed a lattice parameter close to the bulk value (0.424 nm), which is a consequence of a low stress state, due to the absence of ion bombardment. The sample deposited at 1000 W has a lattice parameter of 0.426 nm, close to that of the stress-free material (a s0.424 nm), probably due to some stress relief. All films have a columnar-type structure, lying in the T and I zone of the 0 Thornton Model. The resistivity of the TiN films is almost constant and close to 60 mV cm independently of the preparation conditions, except for the films deposited at 1000 W, r;215 mV cm, and for the grounded sample, r;153 mV cm. These values are probably due to cracks associated with stress relieves, in the first case, and the lack of ion bombardment that leads to films with lower density and higher number of defects in the second. No significant variations in colour were observed.
Clubroot, caused by Plasmodiophora brassicae, is a worldwide disease affecting Brassica. Until now, the detection of genetic factors (QTLs) implicated in clubroot resistance has been based on estimates of disease index. However, as the amount of resting spores released in soil after club disintegration influences clubroot epidemics and resistance‐breaking dynamics, its genetic control may deserve specific attention. In a previous report, it was shown that nitrogen fertilization modulated quantitative partial resistance toward clubroot symptom development in rapeseed. The present work aimed to identify genetic factors involved in the control of resting spore production and to assess their regulation by nitrogen supply. A flow cytometer method was adapted for rapidly estimating resting spore content in a large series of samples. Linkage analysis was conducted to detect QTLs implicated in resting spore production in a Brassica napus doubled haploid progeny from the cross Darmor‐bzh × Yudal. DH lines inoculated with the P. brassicae isolate eH were grown under low‐ and high‐nitrogen supply. Under low‐nitrogen conditions, resting spore production was reduced compared to high‐nitrogen conditions, regardless of genotypes. Genetic architecture controlling resting spore production and clubroot symptom development was similar. Under high‐nitrogen conditions, resting spore production was controlled by one major QTL (C09a) and a few small‐effect QTLs. By contrast, two major QTLs (C02 and C09a) controlled resting spore production under low‐nitrogen conditions. This work highlighted a large see‐saw effect between the relative contribution of the C09a QTL (high effect under high‐nitrogen conditions) and the C02 QTL (high effect under low‐nitrogen conditions), with possible implications in resistance breeding.
Purpose: To compare visual, refractive and safety outcomes of central-hole posterior chamber collamer phakic intraocular lens implantation for low and moderate-to-high myopia. Subjects/methods: This retrospective cohort study included 338 eyes submitted to posterior chamber collamer phakic intraocular lens implantation that completed a 12-month postoperative follow-up. Two groups were defined depending on preoperative spherical equivalent: group 1 comprised 106 eyes with manifest spherical equivalent of −6.00 D or less; group 2 comprised 232 eyes with manifest spherical equivalent higher than −6.00 D. Effectiveness, predictability, stability and safety outcomes were compared preoperatively and at 1, 6 and 12 months postoperatively. Results: At 1-year postoperative, uncorrected and corrected visual acuities were 0.02 ± 0.17 and −0.01 ± 0.12 logMAR (group 1) and 0.04 ± 0.20 and 0.01 ± 0.16 logMAR (group 2), with an efficacy index of 1.05 ± 0.17 and 1.17 ± 0.28. Respectively, 92 (86.8%) and 199 (85.8%) eyes were within ±0.50 D of targeted refraction, and postoperative manifest refraction changes were −0.07 ± 0.25 D and −0.07 ± 0.35 D. Intraocular pressure did not change significantly. The mean rate of endothelial cell loss was 1.12% and 1.10%, respectively. One case of anterior subcapsular cataract (group 2) was observed. ICL exchange occurred in one case (group 1) and three cases (group 2). No vision-threatening complications were reported. Conclusion: The posterior chamber collamer phakic intraocular lens implantation demonstrated high visual and refractive efficacy with an excellent safety profile for the correction of both low and moderate-to-high myopia, revealing equivalent 1-year outcomes regardless of the degree of preoperative myopia.
Nanocomposite thin films composed by (BaTiO3)1–x –(CoFe2O4)x with different cobalt ferrite concentrations (x) have been deposited by pulsed laser ablation on platinum covered Si(001) substrates. The films structure was studied by X‐ray diffraction and Raman spectroscopy. It was found that the CoFe2O4 phase unit cell was compressed along the growth direction of the films, and it relaxed with increasing x. The opposite behavior was observed in the BaTiO3 phase where the lattice parameters obtained from the X‐ray measurements presented a progressive distortion of its unit cell with increasing x. The presence of the strain in the films induced a blueshift of the Raman peaks of CoFe2O4 that decreased with increasing CoFe2O4 concentration. Cation disorder in the cobalt ferrite was observed for lower x, where the nanograins are more isolated and subjected to more strain, which was progressively decreased for higher CoFe2O4 content in the films. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Chain reorientation may be induced in polyvinylidene fluoride (PVDF) in its β-phase by applying a deformation perpendicular to the pre-oriented polymeric chains. This reorientation begins right after the yielding point and seems to be completed when the stress-strain curve stabilizes. We have studied the chain reorientation mechanism by scanning electron microscopy (SEM) and dielectric relaxation methods and we have analyzed its influence in the αand β-relaxations of the polymer. SEM images confirm the existence of a reorientation upon transversal deformation. The decrease of crystallinity with increasing reorientation and the dependence of the dielectric permittivity upon deformation indicate that a model of stress-induced melting followed by an incomplete recrystallization properly describes the reorientation mechanism.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.