65 research outputs found
Nodular Posterior Scleritis: Clinico-Sonographic Characteristics and Proposed Diagnostic Criteria
Purpose: To report the clinical and ultrasound features and outcomes of a series of nodular posterior scleritis. / Methods: Retrospective medical record review of 11 consecutive patients with nodular posterior scleritis. Patient demographics, ocular and systemic findings, ultrasound features, and final anatomical and visual outcomes were recorded. / Results: There were 9 females and 2 males (11 eyes) with mean age at presentation of 57 years (range, 30-84 years). Underlying systemic inflammatory disease was present in 73%. Symptoms included pain in 73% and blurred vision in 45%. A solitary amelanotic mass without the presence of lipofuscin was found in all cases. Associated ocular features included retinal pigment epithelial changes (67%), intraocular inflammation (55%), subretinal fluid (50%), macular edema (50%), and choroidal folds (30%). B-mode ultrasound showed a sclerochoroidal mass with high internal reflectivity (100%) of mean elevation of 4.1 mm. There was nodular thickening of the sclera (100%) and fluid in Tenon space or "T" sign (36%). A complete regression of the nodule after the treatment was observed only in 1 patient (11%) and partial regression in 4 patients (44%). / Conclusion: Nodular posterior scleritis should be considered in the differential diagnosis of a single amelanotic choroidal mass showing high internal reflectivity on ultrasound B-scan. It can produce intraocular inflammation in 50% of the cases and may be painless in 25%. It has a high association with a systemic underlying disease
On the Stereochemistry of the Cations in the Doping Block of Superconducting Copper-Oxides
Metal-oxygen complexes containing Cu,- Tl-, Hg-, Bi- and Pb-cations are
electronically active in superconducting copper-oxides by stabilizing single
phases with enhanced , whereas other metal-oxygen complexes deteriorate
copper-oxide superconductivity. Cu, Tl, Hg, Bi, Pb in their actual oxidation
states are closed shell or inert pair ions. Their electronic
configurations have a strong tendency to polarize the oxygen environment. The
closed shell ions with low lying
excitations form linear complexes through hybridization polarizing
the apical oxygens. Comparatively low excitation energies
distinguish from other closed shell
ions deteriorating copper-oxide superconductivity, {\it e.g.} .Comment: 5 pages, uses REVTEX. To be published in: J. Superconductivity, Proc.
Int. Workshop on "Phase Separation, Electronic Inhomogenities and Related
Mechanisms for High T_c Superconductors", Erice (Sicily) 9-15 July 199
Raman spectral indicators of catalyst decoupling for transfer of CVD grown 2D materials
Anharmonic motion versus chemical bonding: on the interpretation of electron densities determined by X-ray diffraction.
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