Chemical binding

About: Chemical binding is a research topic. Over the lifetime, 1822 publications have been published within this topic receiving 52516 citations.

Copper-based oil bearing material and preparation method thereof

Abstract: The invention discloses a graphene/copper oil bearing material and a preparation method thereof, and belongs to the field of graphene reinforced metal-matrix composites Nickel powder, tin powder, copper powder and a dispersing agent are loaded on graphene according to a certain mass fraction for burdening, a planetary ball mill is used for mixing, and a graphene/copper-based oil bearing is obtained through pressing, sintering, oil immersing and die full shaping processes The graphene is introduced by loading nickel particles on the graphene, and the purpose that graphene strengthening phases are evenly dispersed in a metal matrix to form strong interfacial chemical binding is achieved On the other hand, copper and nickel form an infinite mutual-soluble solid solution, and the solid solution strengthening effect is achieved The graphene/copper-based oil bearing manufactured through the method is even in structure and has good heat-conducting performance and high strength and abrasion resistance

MSA-Regularized Protein Sequence Transformer toward Predicting Genome-Wide Chemical-Protein Interactions: Application to GPCRome Deorphanization.

Abstract: Small molecules play a critical role in modulating biological systems. Knowledge of chemical-protein interactions helps address fundamental and practical questions in biology and medicine. However, with the rapid emergence of newly sequenced genes, the endogenous or surrogate ligands of a vast number of proteins remain unknown. Homology modeling and machine learning are two major methods for assigning new ligands to a protein but mostly fail when sequence homology between an unannotated protein and those with known functions or structures is low. In this study, we develop a new deep learning framework to predict chemical binding to evolutionary divergent unannotated proteins, whose ligand cannot be reliably predicted by existing methods. By incorporating evolutionary information into self-supervised learning of unlabeled protein sequences, we develop a novel method, distilled sequence alignment embedding (DISAE), for the protein sequence representation. DISAE can utilize all protein sequences and their multiple sequence alignment (MSA) to capture functional relationships between proteins without the knowledge of their structure and function. Followed by the DISAE pretraining, we devise a module-based fine-tuning strategy for the supervised learning of chemical-protein interactions. In the benchmark studies, DISAE significantly improves the generalizability of machine learning models and outperforms the state-of-the-art methods by a large margin. Comprehensive ablation studies suggest that the use of MSA, sequence distillation, and triplet pretraining critically contributes to the success of DISAE. The interpretability analysis of DISAE suggests that it learns biologically meaningful information. We further use DISAE to assign ligands to human orphan G-protein coupled receptors (GPCRs) and to cluster the human GPCRome by integrating their phylogenetic and ligand relationships. The promising results of DISAE open an avenue for exploring the chemical landscape of entire sequenced genomes.

Fabrication and structural characterization of plasma polymerized polypyrrole thin film

Abstract: Polypyrrole films deposited on glass or silicon substrates by plasma polymerization under different radio frequency power are investigated in this study. Targeting on electrical conduction, lower RF power for deposition is particularly chosen. The microstructures of deposited films were carefully studied by following instruments; Scanning electron microscope for surface morphology; Fourier transform infrared spectroscopy for the molecular vibrational modes; X-ray photoelectron spectroscopy for chemical binding energy; Energy-dispersive X-ray spectroscopy for elemental composition; current-voltage measure for electrical resistance. Results from these material characterizations indicate that a stronger plasma field breaks down the pyrrole rings while creates more nitrogen groups containing N − H, C − N + or C = N + . However, a certain amount of undamaged pyrrole rings were deposited into films. These intact pyrrole rings make electrical conduction to be possible in films. From the linear regression for the measured current-voltage data, we found that lower RF power (10 W) can improve the electrical conduction; however, a noticeable enhancement in conduction is achieved by the doping of iodine such that the film's electrical resistance is reduced to almost half of other un-doped pyrrole films.

Binding entropy and its application to solids.

Abstract: The concept of binding entropy is introduced and information theoretical approach is combined with orbitalfree density functional theory. It is shown that binding entropy expresses the deviation of the molecular electron density from the promolecular density and the deviation of the molecular kinetic energy density from the promolecular kinetic energy density. The change of the kinetic energy density during the chemical bond formation explicitly appears in the binding entropy expression. The binding entropy and binding entropy density are analyzed using experimental electron density for solid germanium, gallium arsenide and dinitrogen tetroxide. It is demonstrated that the binding entropy joined with deformation electron density and “deformation” kinetic energy density, carries information about both the bonding and binding details and provides a deeper insight into the nature of chemical bond. Atomic and global binding entropies also appeared to be useful descriptors giving a compact description of chemical binding.

Cell sorting using immunomagnetic beads.

Abstract: Immunomagnetic beads are uniform, polymer particles coated with a polystyrene shell that provides both a smooth hydrophobic surface to facilitate physical absorption of molecules, such as antibodies, and surface hydroxyl groups that allow covalent chemical binding of other bioreactive molecules, such as streptavidin, lectins, and peptides. Iron (III) oxide (Fe(2)O(3)) deposited in the core gives the beads superparamagnetic properties that lead to consistent and reproducible reactions to a magnetic field without permanent magnetization of the particles. These are the two qualities on which immunomagnetic separation (IMS) depends.