Mutations in elongation of very long-chain fatty acid-4 (ELOVL4) are associated with autosomal dominant Stargardt-like macular degeneration (STGD3), with a five base-pair (5 bp) deletion mutation resulting in the loss of 51 carboxy-terminal amino acids and truncation of the protein. In addition to the retina, Elovl4 is expressed in a limited number of mammalian tissues, including skin, with unknown function(s). We generated a knock-in mouse model with the 5-bp deletion in the Elovl4 gene. As anticipated, mice carrying this mutation in the heterozygous state (Elovl4(+/del)) exhibit progressive photoreceptor degeneration. Unexpectedly, homozygous mice (Elovl4(del/del)) display scaly, wrinkled skin, have severely compromised epidermal permeability barrier function, and die within a few hours after birth. Histopathological evaluation of the Elovl4(del/del) pups revealed no apparent abnormality(ies) in vital internal organs. However, skin histology showed an abnormally-compacted outer epidermis [stratum corneum (SC)], while electron microscopy revealed deficient epidermal lamellar body contents, and lack of normal SC lamellar membranes that are essential for permeability barrier function. Lipid analyses of epidermis from Elovl4(del/del) mice revealed a global decrease in very long-chain fatty acids (VLFAs) (i.e., carbon chain > or =C28) in both the ceramide/glucosylceramide and the free fatty-acid fractions. Strikingly, Elovl4(del/del) skin was devoid of the epidermal-unique omega-O-acylceramides, that are key hydrophobic components of the extracellular lamellar membranes in mammalian SC. These findings demonstrate that ELOVL4 is required for generating VLFA critical for epidermal barrier function, and that the lack of epidermal omega-O-acylceramides is incompatible with survival in a desiccating environment.

The 3D printing techniques showed significant differences in precision of all measurements and in trueness of tooth and arch measurements. The PolyJet and DLP techniques were more precise than the FFF and SLA techniques, with the PolyJet technique having the highest accuracy.

Colloidal AuNPs show potential as a blood-pool agent for x-ray CT imaging.

BACKGROUND Disparities in healthcare access and delivery, caused by transportation and health workforce difficulties, negatively impact individuals living in rural areas. These challenges are especially prominent in older adults. DESIGN We systematically evaluated the feasibility, acceptability, and effectiveness in providing telemedicine (TMed), searching the English‐language literature for studies (January 2012 to July 2018) in the following databases: Medline (PubMed); Cochrane Library (Wiley); Web of Science; CINAHL; EMBASE (Ovid); and PsycINFO (EBSCO). PARTICIPANTS Older adults (mean age = 65 years or older, and none were younger than 60 years). INTERVENTIONS Interventions consisted of live, synchronous, two‐way videoconferencing communication in nonhospital settings. All medical interventions were included. MEASUREMENTS Quality assessment, using the Cochrane Collaboration's Risk‐of‐Bias Tool, was applied on all included articles, including a qualitative summary of all articles. RESULTS Of 6616 citations, we reviewed the full text of 1173 articles, excluding 1047 that did not meet criteria. Of the 17 randomized controlled trials, the United States was the country with the most trials (6 [35%]), with cohort sizes ranging from 3 to 844 (median = 35) participants. Risk of bias among included studies varied from low to high. Our qualitative analysis suggests that TMed can improve health outcomes in older adults and that it could be used in this population. CONCLUSIONS TMed is feasible and acceptable in delivering care to older adults. Research should focus on well‐designed randomized trials to overcome the high degree of bias observed in our synthesis. Clinicians should consider using TMed in routine practice to overcome barriers of distance and access to care. J Am Geriatr Soc 67:1737–1749, 2019

International relations scholars make frequent use of pooled cross-sectional regression in which N dyads over T time points are combined to create NT observations. Unless special conditions are met, these regressions produce biased estimates of regression coefficients and their standard errors. A survey of recent publications in international relations shows little attention to this issue. Using data from the period 1951–92, we examine the consequences of pooling for models of militarized disputes and bilateral trade. When pooled models are reestimated to allow for stable but unobserved differences among dyads, the results are altered in fundamental ways.