Virus shapes and buckling transitions in spherical shells

We show that the icosahedral packings of protein capsomeres proposed by Caspar and Klug for spherical viruses become unstable to faceting for sufficiently large virus size, in analogy with the buckling instability of disclinations in two-dimensional crystals. Our model, based on the nonlinear physics of thin elastic shells, produces excellent one parameter fits in real space to the full three-dimensional shape of large spherical viruses. The faceted shape depends only on the dimensionless Foppl-von Karman number \gamma=YR^2/\kappa, where Y is the two-dimensional Young's modulus of the protein shell, \kappa is its bending rigidity and R is the mean virus radius. The shape can be parameterized more quantitatively in terms of a spherical harmonic expansion. We also investigate elastic shell theory for extremely large \gamma, 10^3 < \gamma < 10^8, and find results applicable to icosahedral shapes of large vesicles studied with freeze fracture and electron microscopy.Comment: 11 pages, 12 figure

Characterization of the peripheral thyroid system of gilthead seabream acclimated to different ambient salinities

Thyroid hormones are involved in many developmental and physiological processes, including osmoregulation. The regulation of the thyroid system by environmental salinity in the euryhaline gilthead seabream (Sparus aurata) is still poorly characterized. To this end seabreams were exposed to four different environmental salinities (5, 15, 40 and 55 ppt) for 14 days, and plasma free thyroid hormones (fT3, ff4), outer ring deiodination and Na+/K+ -ATPase activities in gills and kidney, as well as other osmoregulatory and metabolic parameters were measured. Low salinity conditions (5 ppt) elicited a significant increase in fT3 (29%) and ff4 (184%) plasma concentrations compared to control animals (acclimated to 40 ppt, natural salinity conditions in the Bay of Cadiz, Spain), while the amount of pituitary thyroid stimulating hormone subunit 13 (tshb) transcript abundance remained unchanged. In addition, plasma fT4 levels were positively correlated to renal and branchial deiodinase type 2 (dio2) mRNA expression. Gill and kidney T4-outer ring deiodination activities correlated positively with dio2 mRNA expression and the highest values were observed in fish acclimated to low salinities (5 and 15 ppt). The high salinity (55 ppt) exposure caused a significant increase in tshb expression (65%), but deiodinase gene expression (diol and dio2) and activity did not change and were similar to controls (40 ppt). In conclusion, acclimation to different salinities led to changes in the peripheral regulation of thyroid hormone metabolism in seabream. Therefore, thyroid hormones are involved in the regulation of ion transport and osmoregulatory physiology in this species. The conclusions derived from this study may also allow aquaculturists to modulate thyroid metabolism in seabream by adjusting culture salinity. (C) 2016 Elsevier Inc. All rights reserved.Socrates/Erasmus Grant from the European UnionUniversity of Cadiz [UCA 2009-074-FPI]Ministerio de Education y Ciencia, Spain [AGL2007-61211/ACU]FEDER, Spain [AGL2007-61211/ACU]Proyecto de Excelencia (Junta de Andalucia) [PO7-RNM-02843]Science Foundation (FCT) of Portugal [SFRH/BPD/89889/2012, SFRH/BPD/84033/2012]info:eu-repo/semantics/acceptedVersio

Cardiac tamponade as an initial manifestation of systemic lupus erythematosus.

Clinical manifestations of pericardial disease may precede other signs and symptoms associated with systemic lupus erythematosus. Although pericardial effusion is one of the most common cardiac problems in patients with systemic lupus erythematosus, haemodynamically significant effusions manifesting as cardiac tamponade are rare and require prompt diagnosis and treatment

Cardiac tamponade as an initial manifestation of systemic lupus erythematosus

Clinical manifestations of pericardial disease may precede other signs and symptoms associated with systemic lupus erythematosus. Although pericardial effusion is one of the most common cardiac problems in patients with systemic lupus erythematosus, haemodynamically significant effusions manifesting as cardiac tamponade are rare and require prompt diagnosis and treatment. Copyright 2012 BMJ Publishing Group. All rights reserved

Non-ketotic hyperglycaemia hemichorea-hemiballismus and acute ischaemic stroke

Here we describe a patient with a rare movement disorder, hemichorea-hemiballismus, which is described as a complication of non-ketotic hyperglycaemia. This complication may be seen in individuals with poorly controlled long-standing diabetes mellitus. Proper diagnosis is established with CT and MRI of the brain, which typically show classic findings in the basal ganglia. Treatment focuses on improvement of glycaemic control and usually results in rapid resolution of the movement disorder. Nevertheless, recurrent episodes of hemichorea-hemiballismus, and even more ominous complications such as ischaemic stroke may occur. Copyright 2013 BMJ Publishing Group. All rights reserved

Techniques for penile augmentation surgery: a systematic review of surgical outcomes, complications, and quality of life

The increase in practices related to enhancing penile size can be attributed to the belief that an improved genital appearance contributes to a man’s virility, coupled with an altered self-perception of his body. It is crucial to tailor interventions to meet the genuine needs of patients by thoroughly assessing their history, psychological state, and potential surgical benefits, all while considering the associated risks of complications. This systematic review aims to summarize the available evidence on outcomes, complications, and quality of life after penile augmentation surgery, examining both minimally invasive and more radical techniques. A search of the PubMed and Scopus databases, focusing on English-language papers published in the last 15 years, was performed in December 2023. Papers discussing surgery in animal models and case reports were excluded from the present study unless further evaluated in a follow-up case series. The primary outcomes were changes in penile dimensions, specifically in terms of length and girth, as well as the incidence of surgical complications and the impact on quality of life. A total of 1670 articles were retrieved from the search and 46 were included for analysis. Procedures for penile length perceived enhancements include lipoplasty, skin reconstruction plasty, V-Y and Z plasty, flap reconstruction, scrotoplasty, ventral phalloplasty, and suspensory ligament release; techniques for increasing corporal penile length include penile disassembly, total phalloplasty, and sliding elongation. Finally, penile girth enhancement may be performed using soft tissue fillers, grafting procedures, biodegradable scaffolds, and Penuma®. In conclusion, while penile augmentation surgeries offer potential solutions for individuals concerned about genital size, the risks and complexities need to be accounted for