A Deep Learning Approach to Denoise Optical Coherence Tomography Images of the Optic Nerve Head

Purpose: To develop a deep learning approach to de-noise optical coherence tomography (OCT) B-scans of the optic nerve head (ONH). Methods: Volume scans consisting of 97 horizontal B-scans were acquired through the center of the ONH using a commercial OCT device (Spectralis) for both eyes of 20 subjects. For each eye, single-frame (without signal averaging), and multi-frame (75x signal averaging) volume scans were obtained. A custom deep learning network was then designed and trained with 2,328 "clean B-scans" (multi-frame B-scans), and their corresponding "noisy B-scans" (clean B-scans + gaussian noise) to de-noise the single-frame B-scans. The performance of the de-noising algorithm was assessed qualitatively, and quantitatively on 1,552 B-scans using the signal to noise ratio (SNR), contrast to noise ratio (CNR), and mean structural similarity index metrics (MSSIM). Results: The proposed algorithm successfully denoised unseen single-frame OCT B-scans. The denoised B-scans were qualitatively similar to their corresponding multi-frame B-scans, with enhanced visibility of the ONH tissues. The mean SNR increased from $4.02 \pm 0.68$ dB (single-frame) to $8.14 \pm 1.03$ dB (denoised). For all the ONH tissues, the mean CNR increased from $3.50 \pm 0.56$ (single-frame) to $7.63 \pm 1.81$ (denoised). The MSSIM increased from $0.13 \pm 0.02$ (single frame) to $0.65 \pm 0.03$ (denoised) when compared with the corresponding multi-frame B-scans. Conclusions: Our deep learning algorithm can denoise a single-frame OCT B-scan of the ONH in under 20 ms, thus offering a framework to obtain superior quality OCT B-scans with reduced scanning times and minimal patient discomfort

Introducing saccharic acid as an efficient iron chelate to enhance photo-Fenton degradation of organic contaminants

The identification of iron chelates that can enhance photo-Fenton degradation is of great interest in the field of advanced oxidation process. Saccharic acid (SA) is a polyhydroxy carboxylic acid and completely non-toxic. Importantly, it can effectively bind Fe(III) as well as induce photoreduction of Fe(III). Despite having these interesting properties, the effect of SA on photo-Fenton degradation has not been studied. Herein, we demonstrate the first assessment of SA as an iron chelate in photo-Fenton process using methylene blue (MB) as a model organic contaminant. Our results demonstrate that SA has the ability to (i) enhance the photo-Fenton degradation of MB by about 11 times at pH 4.5 (ii) intensify photochemical reduction of Fe(III) to Fe(II) by about 17 times and (iii) accelerate the rate of consumption of H2O2 in photo-Fenton process by about 5 times (iv) increase the TOC reduction by about 2 times and (v) improve the photo-Fenton degradation of MB in the presence of a variety of common inorganic ions and organic matter. The influential properties of SA on photo-Fenton degradation is attributed to the efficient photochemical reduction of Fe(III) via LMCT (ligand to metal charge transfer reaction) to Fe(II), which then activated H2O2 to generate OH center dot and accelerated photo-Fenton degradation efficiency. Moreover, the effect of operational parameters such as oxidant: contaminant (H2O2: MB) ratio, catalyst: contaminant (Fe(III)SA: MB) ratio, Fe(III): SA stoichiometry and pH on the degradation of MB by photo-Fenton in the presence of SA is demonstrated. Importantly, SA assisted photo-Fenton caused effective degradation of MB and 4-Chiorophenol under natural sunlight irradiation in natural water matrix. The findings strongly support SA as a deserving iron chelate to enhance photo-Fenton degradation. (C) 2016 Elsevier Ltd. All rights reserved

Rosai–Dorfman disease with isolated lacrimal gland enlargement

Rosai–Dorfman Disease also called as Sinus Histiocytosis with Massive Lymphadenopathy is a rare, benign, idiopathic histiocytic proliferative disorder that occurs predominantly in children and young adults. Orbital involvement can occur in 11% of cases. Isolated lacrimal gland involvement without any local or systemic recurrence is very rare. To the best of our knowledge, only seven cases have been reported in the literature till date. Histopathological and immunohistochemical confirmation is essential in establishing the diagnosis. A benign course is usual, but in some cases, blindness or even fatality may result. We report a case of 30-year-old female with isolated lacrimal gland involvement and 19 months' follow-up

Embryonal rhabdomyosarcoma of the chest wall: A case report and review of the literature

Embryonal rhabdomyosarcoma is a soft-tissue sarcoma which has a predilection for the head and neck area, genitourinary tract and the extremities. We report a rare case of embryonal rhabdomyosarcoma of the chest wall in an 8-year-old girl, presenting as a destructive tumor in the rib and clinically and radiologically mimicking Ewing′s sarcoma. Histopathological examination showed a small round cell tumor. Immunohistochemically, the positivity for muscle markers desmin and myogenin in the tumor cells proved to be useful for making a definitive diagnosis of embryonal rhabdomyosarcoma. Cytogenetic analysis revealed a high level of aneuploidy in the tumor cells, with double-minutes and additional chromosomal structural aberrations. The patient is responding well to chemotherapy

Photochemical detoxification of Cr(VI) using iron and saccharic acid: insights from cytotoxic and genotoxic assays

Herein, we demonstrate rapid and complete photochemical detoxification of Cr(VI) by iron using saccharic acid (SA) as a sacrificial organic agent. 100% Cr(VI) (200 mu M) was reduced within 30 min using Fe(III) (50 mu M) and SA (300 mu M) under UV irradiation. The reaction mechanism involves photochemical recycling of Fe(III)/Fe(II) by SA via ligand to metal charge transfer (LMCT) along with the generation of a concomitant ligand radical and hydroperoxyl radical. Importantly, the MTT assay and gamma H2AX immunostaining were performed to evaluate the hitherto unexplored comparison of cytotoxicity and genotoxicity caused by untreated and treated aqueous Cr(VI). The results revealed that the Fe(III)/SA/UV treatment caused the complete removal of cytotoxic and genotoxic effects of Cr(VI) towards human cell lines. The presence of nitrate, chloride and natural organic matter increased the Cr(VI) reduction, while phosphate decreased the Cr(VI) reduction. Cu(II), Al(III) and Ni(II) had a positive effect on the Cr(VI) reduction. Furthermore, the Fe(III)/SA/UVC treatment caused almost complete Cr(VI) reduction in groundwater, lake water, and simulated galvanic wastewater. This study strongly supports the aptness of the Fe(III)/SA photochemical system for detoxification of Cr(VI) contaminated wastewater