From the Cover: Rational design of helical architectures

Nature has mastered the art of creating complex structures through self-assembly of simpler building blocks. Adapting such a bottom-up view provides a potential route to the fabrication of novel materials. However, this approach suffers from the lack of a sufficiently detailed understanding of the noncovalent forces that hold the self-assembled structures together. Here we demonstrate that nature can indeed guide us, as we explore routes to helicity with achiral building blocks driven by the interplay between two competing length scales for the interactions, as in DNA. By characterizing global minima for clusters, we illustrate several realizations of helical architecture, the simplest one involving ellipsoids of revolution as building blocks. In particular, we show that axially symmetric soft discoids can self-assemble into helical columnar arrangements. Understanding the molecular origin of such spatial organisation has important implications for the rational design of materials with useful optoelectronic applications.     

Lambl's Excrescences Involving the Pulmonary Valve Detected by Transesophageal Echocardiography

We report the first case of echocardiographically detected Lambl's excrescences on the pulmonary valve in a 72-year-old man who was referred for transesophageal echocardiography as a part of an evaluation for ischemic stroke. A total of four excrescences were noted on the arterial aspect of the pulmonary valve; two of them were on the anterior cusp, one was on the left cusp, and one was on the right cusp. The excrescence on the left cusp was the largest, measuring 5 mm in length. These valvular strands (Lambl's excrescences) represented an incidental finding and were not associated with any disease process.     

Comprehensive Biomarker Testing of Glycemia,Insulin Resistance,and Beta Cell Function Has Greater Sensitivity to Detect Diabetes Risk Than Fasting Glucose and HbA1c and Is Associated with Improved Glycemic Control in Clinical Practice

Blood-based biomarker testing of insulin resistance (IR) and beta cell dysfunction may identify diabetes risk earlier than current glycemia-based approaches. This retrospective cohort study assessed 1,687 US patients at risk for cardiovascular disease (CVD) under routine clinical care with a comprehensive panel of 19 biomarkers and derived factors related to IR, beta cell function, and glycemic control. The mean age was 53?±?15, 42 % were male, and 25 % had glycemic indicators consistent with prediabetes. An additional 45 % of the patients who had normal glycemic indicators were identified with IR or beta cell abnormalities. After 5.3 months of median follow-up, significantly more patients had improved than worsened their glycemic status in the prediabetic category (35 vs. 9 %; P?HbA1c values of 5.5–5.6; 56 vs. 18 %, p?相似文献   

Simultaneous occurrence of neuroretinitis and optic perineuritis in a single eye.

A 52-year-old woman presented with pain, decreased visual acuity, decreased color vision, and visual field loss in the OD. Fundus examination revealed optic disc edema and later a macular star figure consistent with neuroretinitis. Magnetic resonance imaging showed enhancement of the orbital optic nerve sheath and perineural fat suggestive of optic perineuritis. The patient was not treated. At 11 months, visual function and fundus examination had returned to normal. This unusual simultaneous occurrence of neuroretinitis and optic perineuritis suggests that these two entities may have a similar pathogenesis.     

Elucidation of the thromboregulatory role of CD39/ectoapyrase in the ischemic brain

Endothelial CD39 metabolizes ADP released from activated platelets. Recombinant soluble human CD39 (solCD39) potently inhibited ex vivo platelet aggregation in response to ADP and reduced cerebral infarct volumes in mice following transient middle cerebral artery occlusion, even when given 3 hours after stroke. Postischemic platelet and fibrin deposition were decreased and perfusion increased without increasing intracerebral hemorrhage. In contrast, aspirin did not increase postischemic blood flow or reduce infarction volume, but did increase intracerebral hemorrhage. Mice lacking the enzymatically active extracellular portion of the CD39 molecule were generated by replacement of exons 4-6 (apyrase-conserved regions 2-4) with a PGKneo cassette. Although CD39 mRNA 3' of the neomycin cassette insertion site was detected, brains from these mice lacked both apyrase activity and CD39 immunoreactivity. Although their baseline phenotype, hematological profiles, and bleeding times were normal, cd39(-/-) mice exhibited increased cerebral infarct volumes and reduced postischemic perfusion. solCD39 reconstituted these mice, restoring postischemic cerebral perfusion and rescuing them from cerebral injury. These data demonstrate that CD39 exerts a protective thromboregulatory function in stroke.     

Surface epithelialization of the type I Boston keratoprosthesis front plate: immunohistochemical and high-definition optical coherence tomography characterization

Background

The aim of this work is to characterize a transparent tissue layer partially covering the anterior surface of the type I Boston permanent keratoprosthesis front plate in four patients.

Methods

The tissue over the front plate was easily scrolled back as a single transparent layer using a sponge. In two cases, histopathologic analysis was undertaken and immunofluorescent staining with a cytokeratin 3-specific antibody was performed. The relationship of the tissue to the keratoprosthesis device was further characterized using spectral domain high-definition optical coherence tomography (HD-OCT).

Results

Histopathologic analysis revealed the tissue to be non-keratinized squamous epithelium. No goblet cells were seen, suggesting the cells were of corneal, and not conjunctival, epithelial origin. Immunofluorescent staining of all cells was positive for cytokeratin 3, a protein strongly associated with corneal epithelium. The tissue was easily discerned by HD-OCT and was of substantial thickness near the external junction between the keratoprosthesis device and the carrier corneal tissue. In three cases, visual acuity was unaffected by the presence or absence of this tissue. In one case, a prominent tissue margin temporarily obscured the visual axis and reduced visual acuity; this resolved with mechanical central debridement and has not recurred.

Conclusions

The transparent tissue layer covering the anterior surface of the type I Boston keratoprosthesis front plate was found to represent non-keratinized squamous epithelium, most likely of corneal epithelial origin. This potentially represents a further step in bio-integration of the keratoprosthesis device. In particular, epithelial coverage of the critical junction between the device and the carrier corneal tissue might serve an important barrier function and further reduce the incidence of infection and extrusion of the type I Boston permanent keratoprosthesis.