Retinopathy of prematurity treatment in the UK: trends in neonatal anaesthetic support and location of treatment from a national surveillance study.

The aim of this study is to evaluate current anaesthetic practice for retinopathy of prematurity (ROP) interventions in the UK. We collected the data from the 12-month prospective British Ophthalmic Surveillance Unit study carried out in 2013/2014 that were analysed with regard to type of anaesthesia used for primary ROP procedures and the hospital department in which treatment took place. A total of 327 cases of treated ROP from 55 different UK units were reported in the study.

Optimized Scintillator YAG:Pr Nanoparticles for X-ray Inducible Photodynamic Therapy.

We describe a sol-gel synthetic method for the production of praseodymium-doped yttrium aluminum garnet (YAG) nanoparticles suitable for X-ray inducible photodynamic therapy (X-PDT). Our sol-gel based approach was optimized by varying temperature and time of calcination, resulting in nanoparticles that were smooth, spherical, and 50-200 nm in crystallite size. The powders were uniformly coated with a thin (10 nm) layer of silica to facilitate surface conjugation with functional moieties.

Deproteinization of Cortical Bone: Effects of Different Treatments.

Bone is a biological composite material having collagen and mineral as its main constituents. In order to better understand the arrangement of the mineral phase in bone, porcine cortical bone was deproteinized using different chemical treatments. This study aims to determine the best method to remove the protein constituent while preserving the mineral component.

Reinforcements in avian wing bones: Experiments, analysis, and modeling.

Almost all species of modern birds are capable of flight; the mechanical competency of their wings and the rigidity of their skeletal system evolved to enable this outstanding feat. One of the most interesting examples of structural adaptation in birds is the internal structure of their wing bones. In flying birds, bones need to be sufficiently strong and stiff to withstand forces during takeoff, flight, and landing, with a minimum of weight.

Triptans and third nerve paresis: a case series of three patients.

PurposeThe aim of this report is to increase awareness of a possible association between cranial nerve paresis and the use of sumatriptan in migraine sufferers, particularly in patients who have additional vascular risk factors.Patients and methodsWe describe a series of three cases where third nerve paresis developed in patients who were treated with the oral form of sumatriptan. All of the patients had a clear history of repetitive migraine headache and none of them had previous third nerve paresis.

Effect of starch on the mechanical and in vitro properties of collagen-hydroxyapatite sponges for applications in dentistry.

This study sought to improve the mechanical and blood-absorbing properties of collagen sponges, while keeping them compressible, by incorporating blended hydroxyapatite (HA)-starch. Results were compared with CollaPlug(®) (pure collagen). The elastic modulus increased from 1.

Distribution of Eu and Eu Ions in Hydroxyapatite: A Cathodoluminescence and Raman Study.

We present a cathodoluminescence study of the spatial distribution of Eu and Eu dopants in hydroxyapatite powders. The results demonstrate that the distribution of europium ions in the hydroxyapatite lattice depends on their valence state. Monochromatic cathodoluminescence images from prismatic powders show that although the Eu is distributed homogeneously in the entire powder volume, the Eu is present mainly at the powder edges.

Experimentally-based multiscale model of the elastic moduli of bovine trabecular bone and its constituents.

The elastic moduli of trabecular bone were modeled using an analytical multiscale approach. Trabecular bone was represented as a porous nanocomposite material with a hierarchical structure spanning from the collagen-mineral level to the trabecular architecture level. In parallel, compression testing was done on bovine femoral trabecular bone samples in two anatomical directions, parallel to the femoral neck axis and perpendicular to it, and the measured elastic moduli were compared with the corresponding theoretical results.

Creep of trabecular bone from the human proximal tibia.

Creep is the deformation that occurs under a prolonged, sustained load and can lead to permanent damage in bone. Creep in bone is a complex phenomenon and varies with type of loading and local mechanical properties. Human trabecular bone samples from proximal tibia were harvested from a 71-year old female cadaver with osteoporosis.

Kinetic characterization of the deproteinization of trabecular and cortical bovine femur bones.

The present study proposes an interpretation of the mechanism of bone deproteinization. Cortical and trabecular bovine femur bones were deproteinized using 6% NaOCl (37, 50, 60°C). The kinetic parameters (rate constant and activation energy) were calculated, and the surface area of each type of bone was considered.

Pain score assessment in babies undergoing laser treatment for retinopathy of prematurity under sub-tenon anaesthesia.

Purpose: To assess the tolerability and outcomes of laser treatment for retinopathy of prematurity (ROP) under sub-tenon anaesthetic with oral or rectal sedation using a reliable, multidimensional, and internationally accepted tool for assessment of neonatal pain.

Methods: Sixty-two babies have had ROP laser treatment in our neonatal unit in the 7-year interval between 1 March 2005 and 28 February 2012; 44% (27 of the 62) were performed using sub-tenon anaesthesia. Pain scores were routinely assessed using the Neonatal Pain Agitation and Sedation Scale (N-PASS) every 10 min during laser treatment.

Highly deformable bones: unusual deformation mechanisms of seahorse armor.

Multifunctional materials and devices found in nature serve as inspiration for advanced synthetic materials, structures and robotics. Here, we elucidate the architecture and unusual deformation mechanisms of seahorse tails that provide prehension as well as protection against predators. The seahorse tail is composed of subdermal bony plates arranged in articulating ring-like segments that overlap for controlled ventral bending and twisting.

Initial anisotropy in demineralized bovine cortical bone in compressive cyclic loading-unloading.

The mechanical properties of demineralized bovine cortical femur bone were investigated by cyclic loading-unloading compression in three anatomical directions (longitudinal, radial, transverse) within the physiological strain range. The loading responses in the radial and transverse directions were nearly linear up to 2% strain, while the response in longitudinal direction was strongly non-linear in that range. The unloading responses were non-linear for each anatomical direction, giving rise to overall loading-unloading hysteresis and cyclic dissipation of energy.

A comparative study of young and mature bovine cortical bone.

The mechanical properties and microstructure of young and mature bovine femur bone were investigated by optical microscopy and compression testing in the longitudinal and transverse directions for untreated, deproteinized and demineralized cases. Optical microscopy revealed that mature bone has a more established and less porous microstructure compared to young bone. Mature bone was found to be stronger in both directions for the untreated and deproteinized cases.

Elastic moduli of untreated, demineralized and deproteinized cortical bone: validation of a theoretical model of bone as an interpenetrating composite material.

A theoretical experimentally based multi-scale model of the elastic response of cortical bone is presented. It portrays the hierarchical structure of bone as a composite with interpenetrating biopolymers (collagen and non-collagenous proteins) and minerals (hydroxyapatite), together with void spaces (porosity). The model involves a bottom-up approach and employs micromechanics and classical lamination theories of composite materials.

Anisotropy in the compressive mechanical properties of bovine cortical bone and the mineral and protein constituents.

The mechanical properties of fully demineralized, fully deproteinized and untreated cortical bovine femur bone were investigated by compression testing in three anatomical directions (longitudinal, radial and transverse). The weighted sum of the stress-strain curves of the treated bones was far lower than that of the untreated bone, indicating a strong molecular and/or mechanical interaction between the collagen matrix and the mineral phase. Demineralization and deproteinization of the bone demonstrated that contiguous, stand-alone structures result, showing that bone can be considered an interpenetrating composite material.

Current dilemmas and controversies in allergic contact dermatitis to ophthalmic medications.

Identifying contact allergens in ophthalmic medications can be a challenging and daunting experience. We summarize data on topical ophthalmic medications with the potential to cause periorbital contact dermatitis and allergic conjunctivitis, highlighting current dilemmas and controversies in this area. The following groups of allergens are reviewed: preservatives, antiglaucoma medications (prostaglandin analogues, β-blockers, carbonic anhydrase inhibitors, parasympathomimetics, sympathomimetics), antiinflammatory medications (nonsteroidal antiinflammatory drugs, corticosteroids), antibiotics, antivirals, antiallergic medications (antihistamines, cromones), anaesthetics, mydriatics, and cycloplegics.

Microstructure, elastic properties and deformation mechanisms of horn keratin.

The structure and mechanical properties of the horns from a desert bighorn sheep, Ovis canadensis, were examined. Horns must be strong and durable as they are subjected to extreme loading impacts, making them superior structural materials. Horns are composed of alpha-keratin, a fibrous, structural protein found in hair, nails, claws and hooves.

Effects of some ophthalmic medications on pupil size: a literature review.

Ophthalmological pharmacology is a rapidly expanding field aimed at achieving the safest and most effective treatment results. Physicians must be aware of the side-effect profiles, both beneficial and harmful, of medications currently used. This review highlights the available data on the effect of some ophthalmic medications on pupil size; it was limited to all reports or studies describing topical ophthalmic agents not originally designed or indicated to alter pupil diameter.

Difficulties imaging herpes simplex keratitis with fluorescein isothiocynate-labeled anti-HSV-1 antibodies in an ex vivo model.

Aim: The aim of this study was to attempt to visualize herpes simplex keratitis in an ex vivo model using currently available ophthalmological equipment and anti-herpes simplex virus 1 (HSV-1) fluorescein isothiocynate-labeled antibody.

Methods: Sixteen donor human corneas were included in this study. Eight corneas were infected with HSV-1, whereas 8 remained uninfected.