Controlling pore structure and conductivity in graphene nanosheet films through partial thermal exfoliation.

Thermal exfoliation is an efficient and scalable method for the production of graphene nanosheets or nanoplatelets, which are typically re-assembled or blended to form new macroscopic "graphene-based materials". Thermal exfoliation can be applied to these macroscopic graphene-based materials after casting to create internal porosity, but this process variant has not been widely studied, and can easily lead to destruction of the physical form of the original cast body. Here we explore how the partial thermal exfoliation of graphene oxide (GO) multilayer nanosheet films can be used to control pore structure and electrical conductivity of planar, textured, and confined GO films. The GO films are shown to exfoliate explosively when the instrument-set heating rates are 100 K/min and above leading to complete destruction of the film geometry. Textured films with engineered micro-wrinkling and crumpling show similar thermal behavior to planar films. Here, we also demonstrate a novel method to produce fairly large size intact rGO films of high electrical conductivity and microporosity based on confinement. Sandwiching GO precursor films between inert plates during partial exfoliation at 250°C produces high conductivity and porosity material in the form of a flexible film that preserves the macroscopic structure of the original cast body.

AK-Score: Accurate Protein-Ligand Binding Affinity Prediction Using an Ensemble of 3D-Convolutional Neural Networks.

Accurate prediction of the binding affinity of a protein-ligand complex is essential for efficient and successful rational drug design. Therefore, many binding affinity prediction methods have been developed. In recent years, since deep learning technology has become powerful, it is also implemented to predict affinity. In this work, a new neural network model that predicts the binding affinity of a protein-ligand complex structure is developed. Our model predicts the binding affinity of a complex using the ensemble of multiple independently trained networks that consist of multiple channels of 3-D convolutional neural network layers. Our model was trained using the 3772 protein-ligand complexes from the refined set of the PDBbind-2016 database and tested using the core set of 285 complexes. The benchmark results show that the Pearson correlation coefficient between the predicted binding affinities by our model and the experimental data is 0.827, which is higher than the state-of-the-art binding affinity prediction scoring functions. Additionally, our method ranks the relative binding affinities of possible multiple binders of a protein quite accurately, comparable to the other scoring functions. Last, we measured which structural information is critical for predicting binding affinity and found that the complementarity between the protein and ligand is most important.

Bifacial CdS/CdTe thin-film solar cells using a transparent silver nanowire/indium tin oxide back contact.

A hybrid silver nanowires (AgNWs)/indium tin oxide (ITO) contact was used as a transparent back-electrode to fabricate a bifacial CdS/CdTe thin-film solar cell. The photovoltaic properties of the bifacial CdS/CdTe thin-film solar cell were investigated under front and back illumination conditions. The hybrid AgNWs/ITO back contact changed the average conversion efficiency from 0.4% (front) and 3.5% (rear) to 8.1% (front) and 0.9% (rear), respectively, improving the sum efficiency from 3.9% (ITO-only) to 9.0%. Our research demonstrates the use of a nanowire network as a transparent electrode in CdS/CdTe thin-film solar cells for bifacial or tandem applications.

MolFinder: an evolutionary algorithm for the global optimization of molecular properties and the extensive exploration of chemical space using SMILES.

Here, we introduce a new molecule optimization method, MolFinder, based on an efficient global optimization algorithm, the conformational space annealing algorithm, and the SMILES representation. MolFinder finds diverse molecules with desired properties efficiently without any training and a large molecular database. Compared with recently proposed reinforcement-learning-based molecule optimization algorithms, MolFinder consistently outperforms in terms of both the optimization of a given target property and the generation of a set of diverse and novel molecules. The efficiency of MolFinder demonstrates that combinatorial optimization using the SMILES representation is a promising approach for molecule optimization, which has not been well investigated despite its simplicity. We believe that our results shed light on new possibilities for advances in molecule optimization methods.

Anti-osteoclastic effect of caffeic acid phenethyl ester in murine macrophages depends upon the suppression of superoxide anion production through the prevention of an active-Nox1 complex formation.

This study investigated the anti-osteoclastic effect of caffeic acid phenethyl ester (CAPE) through suppression of Nox1-mediated superoxide anions production. The multi-nucleated cells were counted and followed by measuring their tartrate-resistant acid phosphatase (TRAP) activity. The superoxide anion production was determined by using fluorescent probe dihydroethidium (DHE). After one day of exposure to the receptor activator of nuclear factor-κB ligand (RANKL), the expression of the proteins involved in superoxide anion production was determined by western blotting. A potent anti-osteoclastic effect of CAPE was observed; the superoxide anion level reached a maximum value after one day of incubation. CAPE attenuated the expression of NADPH (nicotinamide adenine dinucleotide phosphate) oxidase 1 (Nox1) and Rac1, and mitigated the RANKL-induced translocation of p47phox to the cell membrane. In addition, CAPE suppressed the expression of nuclear factor-kappa B (NF-κB p65), its translocation to the nucleus, and the activation of NF-κB inhibitor (IκBα) and its kinase (IKKß). Furthermore, CAPE diminished the expression and activation of the c-jun N-terminal kinase (JNK) and the expression of protein-1 activators (AP-1) such as c-Fos and c-Jun. The expression of Nox1 was suppressed by CAPE through the down-regulation of IKKß/IκBα/NF-κB and JNK/AP-1 signal pathway. This study provides evidence that the anti-osteoclastic effect of CAPE depends upon the attenuated superoxide anion production, which is closely related with interruption of an active Nox1 complex formation due to the attenuated catalytic subunit Nox1 expression resulting from suppression of the IKKß/IκBα/NF-κB and JNK/AP-1 signaling pathway and the down-regulation of the p47phox subunit translocation to the cell membrane.