Approaches to modelling the shape of nanocrystals

Unlike in the bulk, at the nanoscale shape dictates properties. The imperative to understand and predict nanocrystal shape led to the development, over several decades, of a large number of mathematical models and, later, their software implementations. In this review, the various mathematical approaches used to model crystal shapes are first overviewed, from the century-old Wulff construction to the year-old (2020) approach to describe supported twinned nanocrystals, together with a discussion and disambiguation of the terminology. Then, the multitude of published software implementations of these Wulff-based shape models are described in detail, describing their technical aspects, advantages and limitations. Finally, a discussion of the scientific applications of shape models to either predict shape or use shape to deduce thermodynamic and/or kinetic parameters is offered, followed by a conclusion. This review provides a guide for scientists looking to model crystal shape in a field where ever-increasingly complex crystal shapes and compositions are required to fulfil the exciting promises of nanotechnology.

On the yielding of a point-defect-rich model crystal under shear: insights from molecular dynamics simulations

In real crystals and at finite temperatures point defects are inevitable. Under shear their dynamics severely influence the mechanical properties of these crystals, giving rise to non-linear effects, such as...

Identification of a monoclonal antibody that targets PD-1 in a manner requiring PD-1 Asn58 glycosylation

Programmed cell death 1 (PD-1) is inhibitory receptor and immune checkpoint protein. Blocking the interaction of PD-1 and its ligands PD-L1/ L2 is able to active T-cell-mediated antitumor response. Monoclonal antibody-based drugs targeting PD-1 pathway have exhibited great promise in cancer therapy. Here we show that MW11-h317, an anti-PD-1 monoclonal antibody, displays high affinity for PD-1 and blocks PD-1 interactions with PD-L1/L2. MW11-h317 can effectively induce T-cell-mediated immune response and inhibit tumor growth in mouse model. Crystal structure of PD-1/MW11-h317 Fab complex reveals that both the loops and glycosylation of PD-1 are involved in recognition and binding, in which Asn58 glycosylation plays a critical role. The unique glycan epitope in PD-1 to MW11-h317 is different from the first two approved clinical PD-1 antibodies, nivolumab and pembrolizumab. These results suggest MW11-h317 as a therapeutic monoclonal antibody of PD-1 glycosylation-targeting which may become efficient alternative for cancer therapy.

Analysis of Statistical Characteristics of Quasi-Breather with Soft-Type of Nonlinearity in the Crystals of A3B Stoichiometry

The research of quasi-breather statistical characteristics in the model crystal of A3B stoichiometry is conducted by means of molecular dynamics method in the paper by the example of Pt3Al. The phonon spectrum of this model crystal, the dependences of mean-square deviation, the coefficient of variation and the average frequency of the model quasi-breather on the time of its existence are obtained. The statistical data analysis allows for the conclusion that a quasi-breather model solution slightly differs from the exact breather corresponding to it in the model under consideration using the interatomic potential obtained by means of embedded atom method (EAM).

A computational study on how structure influences the optical properties in model crystal structures of amyloid fibrils

Different types of hydrogen bonding interactions that occur in amyloids model systems and molecular factors that control the susceptibility of the protons to undergo proton transfer and how this couples to the optical properties.

Performance optimization of the electro-optic Q-Switching for high power laser using RTP crystal

In order to study the performance of proposal model crystal constructed from(Rubidium Titanly Phosphate, RTP) the birefringence, electric field application, optical,Influences of the most parametric on the electro-optical Q-switching operated for high powerlasers are accomplished. The voltage requirements for productions Q-switching operationwith electro-optical pockels-cells by means of this proposal as transversal configuration cellcrystal have been minimized from 1.900 kV to 1.808 kV for RTP cell these values werereduced in this work owing to the reduction of the thickness to length ratio of this crystal cell.The RTP crystal can be used with longitudinal electric field which is more suitablefor high electro-optical modulation of high power lasers, but with extreme half-wave voltage,which is measured in this work and found to be 9.143 kV and 6.363 kV for x and y directionrespectively .Also, in this work, interpolated treatments on the measurements were applied usingquarter-wave plate (Vλ/4) arrangement, which offered high improvement for using the linearof the transmission-voltage schemes to select the suitable requirement voltage for any levelsswitching.

Research on Key Technology of CAD for Crystal Lamp with Planar Distribution

Crystal lamp has been preferred in indoor lighting design because of its gorgeous effect of light. Crystal lamp has many same or similar elements in the structure, so using CAD technology can help designers to quickly design and model crystal lamp. In this paper, the planar distribution of crystal lamp has been divided into two kinds of situations such as the concentric form crystal distribution and the rectangular form crystal distribution. Aiming at each situation, mathematical analysis has been done and the pseudo-code been given respectively. Then a parameterized modeling plug-in for crystal lamp aided design based Rhinoceros platform has been developed by using VB language. By selecting the parameters and variables, the plug-in can automatically create 3D model of crystal lamp, thus realize the parameterized modeling and improve the efficiency of design.