Aromatic polyimides (PI1x) with a tetraphenylnaphthalene unit between ether linkages were synthesized from 1,4-bis[4-(aminophenoxy)phenyl]-2,3-diphenylnaphthalene (1) and various tetracarboxylic dianhydrides by a conventional two-step procedure that included ring-opening polymerization in N-methyl-2-pyrrolidone and subsequent thermal cyclic dehydration. PI1x were characterized by X-ray diffraction, differential scanning calorimetry, thermogravimetry, and dynamic mechanical analysis. PI1x had glass transition temperatures in the range of 270–315°C and all PI1x were amorphous. The structure–property relationships of these PIs were examined and compared with those of polyimides (PI2x) from 4,4′-bis(4-aminophenoxy)biphenyl (2) and polyimides (PI3x) from 1,4-bis(4-aminophenyl)-2,3-diphenylnaphthalene (3). Water absorption and dielectric constants ( ε) of the PIs were also compared and discussed on the basis of imide content per repeating unit.
Background: Macular hole (MH) is a retinal break in the fovea involving partial or complete dehiscence of the neural retinal layers affecting the visual quality by decreasing visual acuity (VA) and visual deformation. We describe a case of secondary MH associated with submacular hemorrhage (SMH) due to polypoidal choroidal vasculopathy (PCV), which showed spontaneous closure. Case presentation: A 67-year-old man developed decreased VA in his right eye due to an SMH. The VA was 20/50, and monthly intravitreal injection of aflibercept was administered three times. The SMH gradually decreased, and 10 months later the external limiting membrane was found to be perforated, resulting in MH. The old clot disappeared, and the MH remained for 10 months. Twenty-three months later, serous retinal detachment (SRD) involving the macula appeared and the MH had disappeared. SRD gradually disappeared, and macular configuration recovered. VA gradually improved and became 20/20 38 months later. Conclusion: Dynamic change of the ultrastructure in an unusual case of secondary-developed and spontaneously closed MH was clearly observed. Although the mechanism was unknown, the small diameter size and exudative PCV are thought to have contributed to the closure.
Rationale: We describe a case of optic disc pit maculopathy (ODP-M) in which vitrectomy with juxtapapillary laser (JPL) treatment led to the reattachment of retinoschisis (RS) as well as serous retinal detachment (SRD). Patient concerns: An 80-year-old man complained of distorted vision and decreased visual acuity (VA) in his left eye for 12 months. Diagnosis: We conducted quantitative functional evaluation on the area of RS and SRD using the Humphrey visual field analyzer. Fundus examination and optical coherence tomography showed SRD and RS in connection with the optic disc. The best-corrected logarithm of the minimum angle of resolution (logMAR) VA was 0.7. Interventions: The patient underwent JPL treatment combined with pars plana vitrectomy. During surgery, posterior vitreous detachment and tamponade were created with sulfur hexafluoride. Outcomes: After surgery, SRD (and subsequently RS) gradually reduced and had completely disappeared at 31 months. VA gradually improved and was 0.0 (logMAR) at 28 months. The analysis of the mean macular thickness of the central 3-mm diameter showed that the macula thickness recovered to 300 μm at 17 months postoperatively. Retinal sensitivity began to improve at 24 months postoperatively and had increased at 48 months postoperatively. Lessons: In conclusion, vitrectomy with JPL treatment for ODP-M had a favorable anatomical outcome as well as a long-term functional outcome. These findings provide useful information for clinicians who are planning a therapeutic strategy, including the choice of surgical procedure for ODP-M.
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.