Correction: Paradox response of cornea to different color intensities of visible light: An experimental study.

[This corrects the article DOI: 10.1371/journal.pone.0196827.].

Paradox response of cornea to different color intensities of visible light: An experimental study.

The technological development is associated with human daily life and had an impact on its social life. Due to the difficulty of estimating the daily exposure to light; research is needed to determine how much natural and man-made lights could affect the cornea. Visible light radiation could have damaging effect on the human eye; the type and degree of damage are related to the duration and the cumulative exposure as well as to the intensity of the rays. There are noticeable increases in using electronic devices and colored lamps in decoration and toys as well, without any specific regulation. We studied the effect of such human activity on the corneal structure and the vibrational characteristics of corneal tissue by Fourier transform infrared spectroscopy. To achieve these goals, Chinchilla rabbits were exposed to two different lux of blue, green or red color lamps. The results indicate that the corneal tissue responds non-specifically to each lux and accordingly the color. The detected changes are including corneal protein secondary structure as well as lipids, in particular phospholipids. This was concomitant with more ordered membrane bilayer and changes in the corneal membrane phase organization. No lux/color-response relationship was established.

Tailoring the properties and functions of phosphate/silk/Ag/chitosan scaffolds.

Two novel silk composites of phosphatic phases with nanosilver/chitosan having enhanced biocompatibility were achieved. Hydroxyapatite and octa calcium phosphates were synthesized in situ within silk fibroin/chitosan/nanosilver composites recently studied. Thermo-gravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) verified their thermal behavior. The structural aspects were characterized applying X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscope (FESEM) with EDAX. Additionally X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared spectroscopy (FTIR) were applied. Mercury porosimeter was used to verify the pore size distribution. The in vitro degradation was followed in D-MEM for 48 h in a cumulative manner for five successive periods. Biochemical analyses of Ca, P and total protein using relevant chemical kits and atomic absorption for silver were performed. ANOVA statistics was carried out. Phosphatic crystalline phases along with the presence of silk, chitosan and nano-silver were developed. The diameters of hydroxyapatite and octa calcium phosphate particles were ~8-17 nm and 15-22 nm respectively. Comparatively higher degradation of Octa composite possessing higher porosity proved in turn more osteoinduction with in situ apatitic development.

Implementation of a wedged-dynamic arc therapy technique for head and neck cancer.

INTRODUCTION: In this study, we designed and evaluated a wedged dynamic arc therapy (W-DAT) to provide the desirable concaved-shape dose distribution to cover the target in the treatment of head and neck sequence cell carcinoma. MATERIALS AND METHODS: Eight patients were treated using W-DAT. The dose prescriptions were 70 Gy and 54 Gy, in 35 fractions, to the sites of the gross planning target volume (PTV1) and the microscopic (PTV2) diseases respectively. This technique consists of four wedged half-arcs of moving multi-leaf collimator leaves to fit PTV1 and shield brain stem at all gantry rotations. These were combined with two anterior-posterior conformal fields of different weighing to improve the dose uniformity. Another two anterior-posterior conformal fields were designed to cover the PTV2. All of the eight fields were half blocked by the normal jaws so there is no dose overlap at the interface between the two targets. RESULTS: Referring to radiation therapy oncology group protocol 0615, 95% of the PTV1 was covered by more than 95% (66.50 Gy) of the prescribed dose, with very low dose inhomogeneity index of 0.0670 ± 0.0007. The maximum dose to 1% of the planning organ at risk volumes-brainstem didn't exceed 56.10 ± 2.17 Gy while the two parotids were well spared as they received a mean dose of 21.97 ± 3.24 Gy. Isocentric ion chamber measurements showed good agreement with the treatment planning system calculated dose with the maximum deviation of 2.40% while film measurements yielded lesser than 4.20% of the pixels failed the acceptance gamma criteria of (3 mm, 3%). CONCLUSION: W-DAT technique was approved in our department as the standard choice for the radical treatment of head and neck sequence cell carcinoma.

Effect of mineral constituents in the bioleaching of uranium from uraniferous sedimentary rock samples, Southwestern Sinai, Egypt.

Bioleaching, like Biotechnology uses microorganisms to extract metals from their ore materials, whereas microbial activity has an appreciable effect on the dissolution of toxic metals and radionuclides. Bioleaching of uranium was carried out with isolated fungi from uraniferous sedimentary rocks from Southwestern Sinai, Egypt. Eight fungal species were isolated from different grades of uraniferous samples. The bio-dissolution experiments showed that Aspergillus niger and Aspergillus terreus exhibited the highest leaching efficiencies of uranium from the studied samples. Through monitoring the bio-dissolution process, the uranium grade and mineralogic constituents of the ore material proved to play an important role in the bioleaching process. The tested samples asserted that the optimum conditions of uranium leaching are: 7 days incubation time, 3% pulp density, 30 °C incubation temperature and pH 3. Both fungi produced the organic acids, namely; oxalic, acetic, citric, formic, malonic, galic and ascorbic in the culture filtrate, indicating an important role in the bioleaching processes.

FTIR assessment of the effect of Ginkgo biloba leave extract (EGb 761) on mammalian retina.

Ginkgo biloba extract has been therapeutically used for several decades to increase peripheral and cerebral blood flow as well as for the treatment of dementia. The extract contains multiple compounds such as flavonoids and terpenoids that are thought to contribute to its neuroprotective and vasotropic effects. In this study, we investigated the effect of prolonged administration of EGb 761, up to 10 weeks, on mammalian retina using Fourier transform infrared spectroscopy (FTIR). Two main groups were involved in this study: the normal group (n = 10); and EGb-administrated group (n = 50) that received-orally-a dose of 40 mg/kg/day EGb 761. The results demonstrated that EGb administration was associated with different beneficial effects on the retinal constituents especially the underlying amide I protein secondary structure components as well as the NH-OH region. It concluded that the optimum daily administration period of EGb (40 mg/kg) for ophthalmic applications that targeting the retina ranges from 5 to 8 weeks.