The molecular design of performance-enhanced intraocular lens composites.

Intraocular lens (IOL) implantation surgery is quite effective in the treatment of blindness caused by cataracts. However, in clinical applications, IOLs readily form glistening. This phenomenon usually occurs for a period after IOL implantation ranging from a few months to several years. The molecular mechanism of the formation of glistening in IOLs is still inconclusive. Failure to understand and explain the molecular mechanism of glistening formation greatly hinders the design and application of new glistening-free IOL materials. Here, in this study, we use molecular dynamics simulation methods to conduct in-depth research on the molecular mechanism of the glistening formation of IOLs, aiming to provide a possible molecular mechanism of glistening. Furthermore, based on this molecular mechanism, we propose a novel strategy of a glistening-free material based on a composite design method to reasonably copolymerize several types of molecules or functional groups, so that the glistening phenomenon can be effectively eliminated. The possible molecular mechanism of glistening formation proposed in this research can offer a solid theoretical basis and guidance for the subsequent construction of glistening-free IOL materials.

A Density Functional Theory Study on Nonlinear Optical Properties of Double Cage Excess Electron Compounds: Theoretically Design M[Cu(Ag)@(NH3 )n ](M = Be, Mg and Ca; n = 1-3).

In this work, we investigated the nonlinear optical (NLO) properties of excess electron electride molecules of M[Cu(Ag)@(NH3 )n ](M = Be, Mg and Ca; n = 1-3) using density functional theory (DFT). This electride molecules consist of an alkaline-earth (Be, Mg and Ca) together with transition metal (Cu and Ag) doped in NH3 cluster. The natural population analysis of charge and their highest occupied molecular orbital suggests that the M[Cu(Ag)@(NH3 )n ] compound has excess electron like alkaline-earth metal form double cage electrides molecules, which exhibit a large static first hyperpolarizability ( ß 0 e ) (electron contribution part) and one of which owns a peak value of ß 0 e 216,938 (a.u.) for Be[Ag@(NH3 )2 ] and vibrational harmonic first hyperpolarizability ( ß z z z nr ) (nuclear contribution part) values and the ratio of ß z z z nr / ß z z z e , namely, η values from 0.02 for Be[Ag@(NH3 )] to 0.757 for Mg[Ag@(NH3 )3 ]. The electron density contribution in different regions on ß z z z e values mainly come from alkaline-earth and transition metal atoms by first hyperpolarizability density analysis, and also explains the reason why ß z z z e values are positive and negative. Moreover, the frequency-dependent values ß(-2ω,ω,ω) are also estimated to make a comparison with experimental measures. © 2018 Wiley Periodicals, Inc.