Central corneal thickness changes in bevel-up versus bevel-down phacoemulsification cataract surgery: study protocol for a randomised, triple-blind, parallel group trial.

INTRODUCTION: Corneal endothelial damage following phacoemulsification is still one of the major concerns of modern day cataract surgery. Although many techniques have been proposed, the risks of posterior capsular rupture and corneal endothelium damage persist. In theory, damage to the corneal endothelium is minimised by delivering the lowest phaco energy only in the direction necessary to emulsify the lens nucleus. Hence, it is believed that the bevel of the needle should be turned towards the nucleus or the nuclear fragment (ie, bevel-down. However, there is a difference of opinion among ophthalmologists with reference to the phaco tip's position (bevel-up vs bevel-down) during phacoemulsification. This subject has not been extensively studied earlier. METHODS AND ANALYSIS: This is a prospective, triple-blinded (trial participant, outcome assessor and the data analyst), randomised controlled trial with 2 parallel groups and with an allocation ratio of 1:1. It will be conducted in a tertiary care hospital, Mangaluru, India. The objective is to compare the postoperative central corneal thickness changes between the bevel-up and bevel-down techniques of phacoemulsification. Patients aged >18 years with immature cataract undergoing phacoemulsification will be selected for the study. The important exclusion criteria are the history of previous significant ocular trauma or intraocular surgery, corneal pathology, pseudoexfoliation syndrome, intraocular inflammation, a preoperative fully dilated pupil 4. After randomisation, patients will undergo phacoemulsification surgery either by a bevel-up or bevel-down procedure. With an estimated power of 80%, the calculated sample size is 55 patients in each group. The recruitment will start from April 2016. ETHICS AND DISSEMINATION: Yenepoya University Ethics Committee, India has approved the study protocol (YUEC/148/2016 on 18 February 2016). It complies with the Declaration of Helsinki, local laws and the International Council for Harmonization-good clinical practices. TRIAL REGISTRATION NUMBER: CTRI/2016/02/006691; Pre-results

Harmful Elements in Estuarine and Coastal Systems

Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

Effect of alkali metal doping on the properties and crystalline perfection of bis(thiourea)zinc(II) chloride crystals

The influence of sodium doping on the properties of bis(thiourea)zinc(II) chloride crystals has been described. The reduction in the intensity observed in powder X-ray diffraction of doped specimen and slight shifts in vibrational frequencies confirm the lattice stress as a result of doping. The incorporation of Na(I) into the crystal lattice was confirmed by energy dispersive X-ray spectroscopy. Surface morphological changes due to doping of the alkali metal are observed by scanning electron microscopy. The TG-DTA studies reveal the purity of the material and no decomposition is observed up to the melting point. The high resolution X-ray diffraction studies reveal that the crystalline quality is improved considerably by doping with alkali metal. High transmittance is observed and cut off lambda is similar to 270 nm