Novel Technique of Transepithelial Corneal Cross-Linking Using Iontophoresis in Progressive Keratoconus

In this work, the authors presented the techniques and the preliminary results at 6 months of a randomized controlled trial (NCT02117999) comparing a novel transepithelial corneal cross-linking protocol using iontophoresis with the Dresden protocol for the treatment of progressive keratoconus. At 6months, there was a significant average improvement with an average flattening of themaximum simulated keratometry reading of 0.72\ub11.20D(P = 0.01); in addition, corrected distance visual acuity improved significantly (P = 0.08) and spherical equivalent refraction was significantly lessmyopic (P = 0.02) 6months a\u17fter transepithelial corneal cross-linkingwith iontophoresis. The novel protocol using iontophoresis showed comparable resultswith standard corneal cross-linking to halt progression of keratoconus during 6-month follow-up. Investigation of the long-term RCT outcomes are ongoing to verify the efficacy of this transepithelial corneal cross-linking protocol and to determine if it may be comparable with standard corneal cross-linking in themanagement of progressive keratoconus

Investigation of adaptive optics imaging biomarkers for detecting pathological changes of the cone mosaic in patients with type 1 diabetes mellitus

Purpose To investigate a set of adaptive optics (AO) imaging biomarkers for the assessment of changes of the cone mosaic spatial arrangement in patients with type 1 diabetes mellitus (DM1). Methods 16 patients with 20/20 visual acuity and a diagnosis of DM1 in the past 8 years to 37 years and 20 age-matched healthy volunteers were recruited in this study. Cone density, cone spacing and Voronoi diagrams were calculated on 160x160 μm images of the cone mosaic acquired with an AO flood illumination retinal camera at 1.5 degrees eccentricity from the fovea along all retinal meridians. From the cone spacing measures and Voronoi diagrams, the linear dispersion index (LDi) and the heterogeneity packing index (HPi) were computed respectively. Logistic regression analysis was conducted to discriminate DM1 patients without diabetic retinopathy from controls using the cone metrics as predictors. Results Of the 16 DM1 patients, eight had no signs of diabetic retinopathy (noDR) and eight had mild nonproliferative diabetic retinopathy (NPDR) on fundoscopy. On average, cone density, LDi and HPi values were significantly different (P<0.05) between noDR or NPDR eyes and controls, with these differences increasing with duration of diabetes. However, each cone metric alone was not sufficiently sensitive to discriminate entirely between membership of noDR cases and controls. The complementary use of all the three cone metrics in the logistic regression model gained 100% accuracy to identify noDR cases with respect to controls. PLOS ONE | DOI:10.1371/journal.pone.0151380 March 10, 2016 1 / 14 OPEN ACCESS Citation: Lombardo M, Parravano M, Serrao S, Ziccardi L, Giannini D, Lombardo G (2016) Investigation of Adaptive Optics Imaging Biomarkers for Detecting Pathological Changes of the Cone Mosaic in Patients with Type 1 Diabetes Mellitus. PLoS ONE 11(3): e0151380. doi:10.1371/journal. pone.0151380 Editor: Knut Stieger, Justus-Liebig-University Giessen, GERMANY Received: December 17, 2015 Accepted: February 27, 2016 Published: March 10, 2016 Copyright: © 2016 Lombardo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data are within the paper and its Supporting Information files. Funding: Research for this work was supported by the Italian Ministry of Health (5x1000 funding), by the National Framework Program for Research and Innovation PON (grant n. 01_00110) and by Fondazione Roma. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Vision Engineering Italy srl funder provided support in the form of salaries for author GL, but did not have any Conclusion The present set of AO imaging biomarkers identified reliably abnormalities in the spatial arrangement of the parafoveal cones in DM1 patients, even when no signs of diabetic retinopathy were seen on fundoscopy

Some uniform bounds for elliptic curves over Q\mathbb Q

We give explicit uniform bounds for several quantities relevant to the study of Galois representations attached to elliptic curves $E/\mathbb Q$. We consider in particular the subgroup of scalars in the image of Galois, the first Galois cohomology group with values in the torsion of $E$, and the Kummer extensions generated by points of infinite order in $E(\mathbb Q)$.Comment: Comments are welcome

All-Optical Method to Assess Stromal Concentration of Riboflavin in Conventional and Accelerated UV-A Irradiation of the Human Cornea.

PURPOSE. We investigated the concentration of riboflavin in human donor corneas during corneal cross-linking using two-photon optical microscopy and spectrophotometry. METHODS. Eight corneal tissues were de-epithelialized and soaked with 20% dextran-enriched 0.1% riboflavin solution for 30 minutes. After stromal soaking, three tissues were irradiated using a 3 mW/cm(2) UV-A device for 30 minutes and three tissues irradiated using a 10 mW/cm2 device for 9 minutes. Two additional tissues were used as positive controls. A Ti:sapphire laser at 810 nm was used to perform two-photon emission fluorescence (TPEF) and second harmonic generation axial scanning measurements in all specimens before and after stromal soaking and after UV-A irradiation. In addition, spectrophotometry was used to collect the absorbance spectra of each tissue at the same time intervals. Analysis of the absorbance spectra and TPEF signals provided measures of the concentration depth profile of riboflavin in corneal stroma. RESULTS. After stromal soaking, the average peak concentration of riboflavin (0.020% +-0.001%) was found between a stromal depth of 100 and 250 lm; the concentration of riboflavin was almost constant up to 320 6 53 lm depth, then decreased toward the endothelium, though riboflavin was still enriched in the posterior stroma (0.016%% 6 0.001%). After conventional and accelerated UV-A irradiation, the concentration of riboflavin decreased uniformly 87% 6 2% and 67% 6 3% (P < 0.001), respectively. CONCLUSIONS. The combined use of two-photon optical microscopy and spectrophotometry provides relevant information for investigating the concentration of riboflavin in corneal stroma. The method can assist with the assessment of novel riboflavin formulations and different UV-A irradiation protocols

Silicon Quasi‐One‐Dimensional Nanostructures for Photovoltaic Applications

Thanks to the silicon abundance, stability, non-toxicity and well known electronic properties, Si based solar cells have represented the leading actors in the photovoltaic market and future projections confirm this predominance. However, half of the module cost is due to the material consumption and processing. In order to decrease the costs, a cut in the Si consumption must be operated, with consequent decrement in the optical absorption, generated current and device efficiency. To keep the performance level, a proper Si surface design with the objective to trap the light, has been developed. One of the most popular approaches is to use silicon nanowires embedded in the solar cell emitter where they play the role of optically and electrically active layer, thanks to their excellent optical absorption properties. However, also another material has been the terminus of the light-trapping materials, the silicon nanoholes. Their mechanical robustness is superior, making their integration inside the cell easier and cost-effective. The review will bring about all of the most common methods to fabricate these two types of nanostructures when used for solar cells applications, their optical properties and some critical aspects related to their high surface to volume ratio which modify the recombination processes

Seismic site response in Siracusa

In the frame of the Italo–Maltese research project (Costituzione di un Sistema Integrato di Protezione Civile Transfrontaliero Italo–Maltese, SIMIT), researches financially supported by the European Community were performed in the area between the south–eastern Sicilian coast and the islands of Lampedusa and Malta. Aim of these stud- ies is to mitigate natural hazards and to develop the geological and geophysical information in the investigated region. The damage to buildings further to a seismic input is tightly linked, besides their vulnerability, to both the characteristics of the maximum acceleration and frequency of the ground motion, as well as to the features of surface geology. From this point of view, the geophysical and geotechnical characterization of the soil conditions, down to the bedrock, is very important in order to identify the site effects, in terms of fundamental frequencies, for a correct planning of earthquake resistant structures.peer-reviewe

The role of slope instability on directional site effects observed at Fekruna Bay, Malta

The Maltese Archipelago is situated in the Mediterranean Sea, about 290 km NE of Tunisia and 90 km South of Sicily. It consists of three major islands: Malta and Gozo, the southerly and northerly islands respectively, and Comino which lies in the Comino straits separating the two largest islands. In order to better preserve the historical heritage, landscapes, and coastal areas and to promote tourism activities it has been proposed that the archipelago might be considered as an open air laboratory. In this context multidisciplinary studies integrating geology, geotechnical earthquake engineering, geomorphology as well as history and archeology were undertaken in order to develop and test methodologies for the assessment of the relationship between physical environment and cultural heritage (e.g., Soldati et al., 2008). The paper focuses on an integrated study about geomorphology and seismic site response in the Fekruna bay, in the area of Xemxija (northen-eastern part of the Malta Island, Fig. 1).N/

Dynamic properties of buildings evaluated through ambient noise measurements

It is well known that the damage level and its distribution during an earthquake is due to the combined effects of seismic hazard in the investigated area, the features of the local site response, based on the near–surface and subsurface ground conditions, as well as on the dynamic features of the erected buildings. The extent of building dam- age and its distribution is indeed tightly linked to the combined effect of local site response and the dynamic features of the human-made structures. The dynamic properties of a building are usually described through its natural frequency (or period T) and the damping ratio (ζ ), the latter representing the energy loss of an oscillating system. The damping ratio is important in seismic design since it allows to evaluate the ability of a structure to dissipate the vibration energy during an earthquake. Such energy causes a structure to have the highest amplitude of response at its fundamental period, which depends on the structure’s mass and stiffness. The knowledge of damping level and fundamental period of the building is therefore particularly important for estimating the seismic base shear force F in designing earthquake resistant structures.peer-reviewe

Seismic site response of unstable steep slope using noise measurements : the case study of Xemxija Bay area, Malta

Landslide phenomena involve the northern coast of Malta, affecting in particular the urban area of Xemxija. Limestones overlying a clayey formation represent the shallower lithotypes that characterize the surficial geology of this area, where lateral spreading phenomena and rockfalls take place. Ambient noise records, processed through spectral ratio techniques, were analysed in order to characterize the dynamic behavior of the rock masses affected by the presence of fractures linked to the landslide body existing in the area. Experimental spectral ratios were also calculated after rotating the horizontal components of the seismic signal, and a direct estimate of the polarization angle was also performed in order to investigate the existence of directional effects in the ground motion. The results of the morphologic survey confirmed the existence of large cliff-parallel fractures that cause cliff-edge and unstable boulder collapses. Such phenomena appear connected to the presence, inside the clay formation, of a sliding surface that was identified through the interpretation of the noise measurement data. The boundaries of the landslide area appear quite well defined by the pronounced polarization effects, trending in the northeastern direction, observed in the fractured zone and in the landslide body in particular.peer-reviewe