94 research outputs found

    Film Granularity and the Effect on Subjective Image Quality

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    The evaluation of subjective image quality in pictures is investigated as a function of the scene content of the images and the grain level of the images . In the pictures studied, no relationship was observed for the effect of scene content when the only other variable was the grain level

    Photoswitchable Self-Complementary Hydrogen Bond Arrays

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    Background: Photochromism is the reversible transformation of a chemical material to another form by the absorption of electromagnetic radiation (light), where the two metastable forms have distinct absorption spectra and other properties. Photochromism in materials allows for the switching of their function solely based on irradiation with light. Polymers are used frequently as the building blocks for materials as they are versatile, multifunctional, can carry charge and be processed by solution-based deposition methods. Supramolecular polymers share the same definition as polymers with the exception that they are held together by reversible and directional non-covalent interactions such as hydrogen bonds. Synthesizing supramolecular polymers with hydrogen bonds can be carried out in two possible arrangements. Hydrogen bonds can form between different (complementary) or the same monomeric end groups (self-complementary). This poster presentation will focus on our recent efforts toward the investigation of the strength and fatigue-resistance of the hydrogen bonding interaction between self-complementary hydrogen bond arrays intended for elaboration in supramolecular polymeric materials. The supramolecular and photophysical properties will be examined using UV-Vis Spectroscopy, Nuclear Magnetic Resonance, and dilution experiments. Future steps include incorporating these photochromic compounds into functional polymers to evaluate the photocontrolled elasticity, molecular alignment and self-healing abilities of the resulting materials

    A Photoswitchable Hydrogen Bond Array

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    Synthesis of a [2]rotaxane through first- and second-sphere coordination

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    In an effort to expand the application of a new template from interpenetrated to interlocked molecular species, we report the synthesis of a new [2]rotaxane by means of both first- and second-sphere coordination of a palladium(II) dichloride subunit

    Surficial Geologic Map of the Des Moines Lobe of Iowa, Huxley and Slater 7.5\u27 quadrangles

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    https://ir.uiowa.edu/igs_ofm/1022/thumbnail.jp

    2,6-Diamino­pyridinium tetra­phenyl­borate–1,2-bis­(5,7-dimethyl-1,8-naphthyridin-2-yl)diazene (1/1)

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    In the title compound, C5H8N3 +·C24H20B−·C20H18N6, the 1,2-bis­(5,7-dimethyl-1,8-naphthyridin-2-yl)diazene mol­ecule is essentially planar (r.m.s. deviation = 0.0045 Å) and aligned in nearly coplanar manner with the 2,6-diamino­pyridinium ion, making a dihedral angle of 5.19 (5)°. The diamino­pyridine mol­ecule is protonated on the central pyridine N atom and the B atom bears the counter-charge. The amine groups of the diamino pyridinium cation form intra­molecular N—H⋯N hydrogen bonds, resulting in linear and bent inter­actions with the naphthyridine ring system

    Incidence and Risk Factors for Retinal Detachment and Retinal Tear after Cataract Surgery: IRIS® Registry (Intelligent Research in Sight) Analysis

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    Objective To report the incidence of and evaluate demographic, ocular comorbidities, and intraoperative factors for rhegmatogenous retinal detachment (RRD) and retinal tear (RT) after cataract surgery in the American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight). Design Retrospective cohort study. Participants Patients aged ≥ 40 years who underwent cataract surgery between 2014 and 2017. Methods Multivariable logistic regression was used to evaluate demographic, comorbidity, and intraoperative factors associated with RRD and RT after cataract surgery. Main Outcome Measures Incidence and risk factors for RRD or RT within 1 year of cataract surgery. Results Of the 3 177 195 eyes of 1 983 712 patients included, 6690 (0.21%) developed RRD and 5489 (0.17%) developed RT without RRD within 1 year after cataract surgery. Multivariable logistic regression odds ratios (ORs) showed increased risk of RRD and RT, respectively, among men (OR 3.15; 95% confidence interval [CI], 2.99–3.32; P \u3c 0.001 and 1.79; 95% CI, 1.70–1.89; P \u3c 0.001), and younger ages compared with patients aged \u3e 70, peaking at age 40 to 50 for RRD (8.61; 95% CI, 7.74–9.58; P \u3c 0.001) and age 50 to 60 for RT (2.74; 95% CI, 2.52–2.98; P \u3c 0.001). Increased odds of RRD were observed for procedure eyes with lattice degeneration (LD) (10.53; 95% CI, 9.82–11.28; P \u3c 0.001), hypermature cataract (1.61; 95% CI, 1.06–2.45; P = 0.03), complex cataract surgery (1.52; 95% CI, 1.4–1.66; P \u3c 0.001), posterior vitreous detachment (PVD) (1.24; 95% CI, 1.15–1.34; P \u3c 0.001), and high myopia (1.2; 95% CI, 1.14–1.27; P \u3c 0.001). Lattice degeneration conferred the highest odds of RT (43.86; 95% CI, 41.39–46.49; P \u3c 0.001). Conclusion In the IRIS Registry, RRD occurs in approximately 1 in 500 cataract surgeries in patients aged \u3e 40 years within 1 year of surgery. The presence of LD conferred the highest odds for RRD and RT after surgery. Additional risk factors for RRD included male gender, younger age, hypermature cataract, PVD, and high myopia. These data may be useful during the informed consent process for cataract surgery and help identify patients at a higher risk of retinal complications. Financial Disclosure(s) The author(s) have no proprietary or commercial interest in any materials discussed in this article
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