Coexistence of macro- and micro-vascular abnormalities in newly diagnosed normal tension glaucoma patients

Purpose: To investigate the coexistence of ocular microvascular and systemic macrovascular abnormalities in early stage, newly diagnosed and previously untreated normal tension glaucoma patients (NTG). Methods: Retinal vascular reactivity to flickering light was assessed in 19 NTG and 28 age-matched controls by means of dynamic retinal vessel analysis (IMEDOS GmbH, Jena, Germany). Using a newly developed computational model, the entire dynamic vascular response profile to flicker light was imaged and used for analysis. In addition, assessments of carotid intima-media thickness (IMT) and pulse wave analysis (PWA) were conducted on all participants, along with blood pressure (BP) measurements and blood analyses for lipid metabolism markers. Results: Patients with NTG demonstrated an increased right and left carotid IMT (p = 0.015, p = 0.045) and an elevated PWA augmentation index (p = 0.017) in comparison with healthy controls, along with an enhanced retinal arterial constriction response (p = 0.028), a steeper retinal arterial constriction slope (p = 0.031) and a reduced retinal venous dilation response (p = 0.026) following flicker light stimulation. Conclusions: Early stage, newly diagnosed, NTG patients showed signs of subclinical vascular abnormalities at both macro- and micro-vascular levels, highlighting the need to consider multi-level circulation-related pathologies in the development and progression of this type of glaucoma.

Is it safe to increase diabetic retinopathy screening intervals in patients with no background diabetic retinopathy?

Introduction. A 4 year retrospective follow up of 996 patients who pre-sented with no DR and 500 with background DR at baseline digital DR screening in 2006. Purpose. To evaluate the safety of increasing screening intervals in patients with no diabetic retinopathy (DR) or with background DR.Methods. A 4 year retrospective follow up of 996 patients who presented with no DR and 500 with background DR at baseline digital DR screening in 2006.results. Background DR Group: Of the 500 subjects that had back-ground DR in 2006, 231 were referred for DR, with an average DR routine referral rate of 12% (46 subjects) per year. nodrgrouP. Of the 996 patients who had no DR at baseline, 51 were referred over the 4 years for sight threatening DR (STDR), of these 45 patients have definite STDR confirmed by ophthalmological examination. 78% of these had type 2 diabetes and mean age at referral was 60 years (25-87). Mean diabetes duration was 10.7 years (3-32), with a mean HbA1c of 7.8% (5.7-11.3%). Eight patients (0.9%) were referred in the first year, 9 (0.9%) in the second year, 19 (1.9%) in the third year and 15 (1.5%) in the fourth year. 86% of referrals were for maculopathy, and all had observable retinopathy and none required ophthalmology clinic assessment or laser treatment.If biannual screening was adopted for patients with no DR at baseline, allowing for patients who subsequently develop background DR and would then revert to annual screening, a total of 7 (0.7%) patients would not have been appropriately referred for STDR and would have waited a further year for identification. None of the 51 referrals across the 4 years required laser treatment apart from just one patient who developed PDR in year 4 (2010) and had background since 2007.conclusIons. It could be recommended that it is safe to screen pa-tients with no DR biannually due to the low risk of developing STDR. However, patients who present with background DR should continue to be screened annually as there is a significant proportion developing STDR and would not be identified at an appropriate screening interval.

New genre of antioxidants from renewable natural resources:synthesis and characterisation of rosemary plant-derived antioxidants and their performance in polyolefins

Several ester derivatives of rosmarinic acid (rosmarinates) were synthesised, characterised (1D and 2D NMR, UV and FTIR spectroscopy) and tested for their potential use as antioxidants derived from a renewable natural resource. The intrinsic free radical scavenging activity of the rosmarinates was assessed, initially using a modified DPPH (2, 2-diphenyl-1-picrylhydrazyl radical) method, and found to be higher than that of commercial synthetic hindered phenol antioxidants Irganox 1076 and Irganox 1010. The thermal stabilising performance of the rosmarinates in polyethylene (PE) and polypropylene (PP) was subsequently examined and compared to that of samples prepared similarly but in the presence of Irganox 1076 (in PE) and Irganox 1010 (in PP) which are typically used for polyolefin stabilisation in industrial practice. The melt stability and the long-term thermo-oxidative stability (LTTS) of processed polymers containing the antioxidants were assessed by measuring the melt flow index (MFI), melt viscosity, oxidation induction time (OIT) and long-term (accelerated) thermal ageing performance. The results show that both the melt and the thermo-oxidative stabilisation afforded by the rosmarinates, and in particular the stearyl derivative, in both PE and PP, are superior to those of Irganox 1076 and Irganox 1010, hence their potential as effective sustainable bio-based antioxidants for polymers. The rosmarinic acid used for the synthesis of the rosmarinates esters in this study was obtained from commercial rosemary extracts (AquaROX80). Furthermore, a large number of different strains of UK-grown rosemary plants (Rosmarinum officinalis) were also extracted and analysed in order to examine their antioxidant content. It was found that the carnosic and the rosmarinic acids, and to a much lesser extent the carnosol, constituted the main antioxidant components of the UK-plants, with the two acids being present at a ratio of 3:1, respectively.

Superior gas-sensing performance of amorphous CdO nanoflake arrays prepared at room temperature

Highly sensitive and selective detection of volatile organic compounds (VOCs) with fast response time is imperative based on safety requirements, yet often remains a challenge. Herein, we propose an effective solution, preparing a novel gas sensor comprised of amorphous nanoflake arrays (a-NFAs) with specific surface groups. The sensor was produced via an extremely simple process in which a-NFAs of CdO were deposited directly onto an interdigital electrode immersed in a chemical bath under ambient conditions. Upon exposure to a widely used VOC, diethyl ether (DEE), the sensor exhibits excellent performance, more specifically, the quickest response, lowest detection limit and highest selectivity ever reported for DEE as a target gas. The superior gas-sensing properties of the prepared a-NFAs are found to arise from their open trumpet-shaped morphology, defect-rich amorphous nature, and surface CO groups.