Iterated series and the Hellinger-Toeplitz theorem

We show that an iterated double series condition due to Antosik implies the uniform convergente of the double series. An application of Antosik's condition is given te the derivation of a vector form of the Hellinger-Toeplitz Theorem

Modeling functional piezoelectricity in perovskite superlattices with competing instabilities

Based on the locality principle of insulating superlattices, we apply the method of Wu {\it et al} [Phys. Rev. Letter {\bf 101}, 087610 (2008)] to the piezoelectric strains of individual layers under fixed displacement field. For a superlattice of arbitrary stacking sequence an accurate model is acquired for predicting piezoelectricity. By applying the model in the superlattices where ferroelectric and antiferrodistortive modes are in competition, functional piezoelectricity can be achieved. A strong nonlinear effect is observed and can be further engineered in the PbTiO$_3$/SrTiO$_3$ superlattice and an interface enhancement of piezoelectricity is found in the BaTiO$_3$/CaTiO$_3$ superlattice.Comment: 5 pages, 4 figure

Severe Clotting During Extracorporeal Dialysis Procedures

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73576/1/j.1525-139X.1991.tb00417.x.pd

The uniform boundedness principle for order bounded operators

Under appropriate hypotheses on the spaces, it is shown that a sequence of order bounded linear operators which is pointwise order bounded is uniformly order bounded on order bounded subsets. This result is used to establish a Banach-Steinhaus Theorem for order bounded operators

Predictors of lost to follow up among patients with ischemic retinopathies: a retrospective cohort study

PURPOSE: Retinal and choroidal ischemic retinopathies such as retinal-vein occlusion (RVO), diabetic retinopathy (DR), and age-related macular degeneration (AMD) are ocular diseases caused by abnormal changes in the microvasculature. The ischemia can lead to macular edema or neovascularization, which can affect vision. Intravitreal injections (IVI) of anti-vascular endothelial growth factor (anti-VEGF) can help to reduce macular edema and improve visual acuity. Lost to follow-up (LTFU) after anti-VEGF injections increases the risk of vision loss in patients with RVO, DR, and AMD. METHODS: Patients scheduled for an IVI of anti-VEGF between September 2009 and September 2019 with either RVO, DR, or AMD were included in the analysis. LTFU was defined as missing an appointment without another evaluation for at least one interval exceeding 180 days. All patients were seen by a single provider at an urban, hospital-based, single-site retina practice in Boston, MA. RESULTS: Among the 698 patients (mean [SD] age, 70.23 [14.2] years; 373 [53.4%] female) identified as receiving an IVI, 121 (17.3%) were LTFU. Age was not found to be statistically different between the LTFU and not LTFU groups (mean difference, -1.67; 95% CI, -4.66¬–1.32; P=.27). Odds of LTFU was lower among patients with AMD (odds ratio [OR], 0.57; 95% CI, 0.36-0.92; P=.02). Odds of LTFU was greater among patients with Medicaid insurance (OR, 2.31; 95% CI, 1.22-4.33; P=.01), compared with patients with Medicare insurance. A trend towards higher risk of LTFU was seen in patients with DR (OR, 1.42; 95% CI, 0.94-2.15; P=.09) and a toward lower risk in patients with two or more eye diseases (OR, 0.53; 95% CI, 0.24-1.15; P=.10). Medicaid insurance was the only significant (P=.02) independent risk factor of LTFU in the multivariate regression. CONCLUSION: We found a high rate of LTFU after anti-VEGF injections among patients with RVO, DR, AMD, and identified risk and protective factors associated with LTFU among this population. Although our results may not be generalizable, data on LTFU in a clinical practice setting are needed to understand the scope of the problem so that interventions may be designed to improve outcomes