Holographic waveguides in photopolymers.

The possibilities that offer the holographic optical elements for photovoltaic and "see through display" applications open new windows for holographic recording materials. In this sense, some specific characteristics are required for each particular application. Waveguides are one of the key elements for these applications. Photopolymers are one of the most competitive candidates for waveguide fabrication. In this work, we evaluate the performance of one example from each of three families of photopolymer material in fabrication of a 633nm waveguide. Firstly, polyvinyl alcohol acrylamide, PVA/AA, the second one, a nanoparticle-thiol-ene, NPC, and on the last place a penta/hexa-acrylate based polymer with dispersed nematic liquid crystal molecules, PDLC. We study the critical role of the material and in particular, spatial resolution for this application.

Meta-analysis and adjusted indirect comparison of direct oral anticoagulants in prevention of acute limb ischemia in patients with atrial fibrillation.

BACKGROUND: Direct oral anticoagulants are being presented as alternatives to warfarin for preventing stroke in patients with atrial fibrillation. Yet direct comparative trials between these agents in prevention of acute limb ischemia (ALI) are unavailable so far. OBJECTIVE: To conduct an adjusted indirect comparison meta-analysis between direct oral agents for prevention of acute limb ischemia in atrial fibrillation. METHODS: We conducted a systematic literature review searching electronic databases (MEDLINE and Embase) and the Cochrane Library from January 1990 through November 2014. Two blinded investigators reviewed all potentially relevant articles in a parallel manner by using a priori defined criteria. To assess the long-term efficacy and safety of these agents, only randomized clinical trials (RCTs) with follow-up durations of >1 year were included. The primary efficacy outcome was the end point of acute limb ischemia and/or extremity embolism. RESULTS: A total of 44,563 patients from three RCTs met criteria for inclusion. Patients randomized to direct oral anticoagulants had a non-significant decreased risk for acute limb ischemia (risk ratio [RR]: 0.57, 95% confidence interval [CI]: 0.26-1.2). In the analysis between agents, however, rivaroxaban significantly lowered the risk of ALI compared to warfarin (RR: 0.23, 95% CI: 0.064-0.82), apixaban (RR: 0.26, 95% CI: 0.081-0.83), and dabigatran (RR: 0.24, 95% CI: 0.077-0.83). CONCLUSIONS: Significant differences in prevention of acute limb ischemia may exist between oral anticoagulant agents in patients with atrial fibrillation. Rivaroxaban lowers the risk of limb embolism versus warfarin, apixaban and dabigatran.

Analysis of vascular endothelial growth factor gene expression in the tissues of patients with chronic venous insufficiency.

OBJECTIVE: Immunohistochemical techniques have revealed the presence of vascular endothelial growth factor (VEGF) in the epidermis of patients with chronic venous disease (CVD). Our objective was to perform a quantitative analysis of the VEGF gene transcription in tissues that are potential sources of this factor (skin, varicose veins [VV] and great saphenous vein [GSV]) in patients with CVD. METHODS: In all, 212 skin and venous tissue samples were collected from patients diagnosed with CVD and controls. The VEGF gene expression was analysed using quantitative realtime polymerase chain reaction (PCR). RESULTS: The skin VEGF expression was lower in the CVD group than in the control group (P = 0.04). There were no significant differences between the insufficient GSV of the CVD group and the control healthy vein (P = 0.22). There was a greater expression of VEGF in the VV of the CVD group than in the control healthy vein (P = 0.03). Comparison of the VEGF expression between the different tissue types in the CVD group revealed significant differences between the skin and GSV (P = 0.02) and between the skin and the VV (P = 0.004), and between the VV and the GSV (P = 0.02). CONCLUSIONS: The results of the present study show an over-expression of VEGF gene in the VV tissue of patients with CVD. Based on the data in patients with C2 disease, the VVs appear to be the source of increased VEGF expression.

Long-term pleiotropic effect of statins upon nitric oxide and C-reactive protein levels in patients with peripheral arterial disease.

OBJECTIVES: Peripheral arterial disease can be regarded as a systemic inflammatory disorder affecting the entire vascular system. In the early clinical stages, it is characterised by the deterioration of endothelial function, which does not progress with the development of the disease. This study analyses the pleiotropic effects upon the plasma nitrite and C-reactive protein (CRP) levels in claudicating patients after 12 months of treatment with statins. STUDY DESIGN: A prospective randomised controlled translational study was made in patients with Fontaine grade II ischaemia, treated with the best medical treatment with or without statins for 12 months from the time of diagnosis for assessing the pleiotropic effects of those statins. METHODS: Measurements of plasma high-sensitivity CRP (hsCRP), lipid profile and nitrites were made at baseline and after 1 month and 1 year of treatment with atorvastatin 40 mg/day. RESULTS: A significant reduction in nitrite levels was observed after 1 month of treatment (11.8±7.8 µM vs 5.7±1.8 µM, p=0.0001), but this effect did not persist after 1 year (11.8±7.8 µM vs 9.4±8.9 µM, p=0.27). HsCRP underwent a significant reduction after both 1 month (7 (2.2-12) vs 3.4 (1.6-5.5), p<0.01) and 1 year of treatment with atorvastatin (7 (2.2-12) vs 2.25 (1.67-6.7), p=0.02). Statin treatment reduced hsCRP levels in 9.64 (95% CI (1.60 to 17.68)) after 1 month and in 9.14 (95% CI (0.18 to 18.47)) after 1 year. CONCLUSIONS: The long-term biological pleiotropic effects of statins provide information on the role of endothelial function and systemic inflammation in the aetiopathogenesis of peripheral arterial disease. Statins slow endothelial degradation at the start of the disease, with no effects over the long term. These drug substances reduce progressive inflammation throughout the treatment period. This supports the novel hypothesis that endothelial dysfunction is only a disease-triggering phenomenon, while systemic inflammation would be responsible for both the origin and the maintenance of peripheral arterial disease.