Read by QxMD icon Read

Van der waal

Kaouther Kerboua, Oualid Hamdaoui
Many models have been established to study the evolution of the bubble dynamics and chemical kinetics within a single acoustic cavitation bubble during its oscillation. The content of the bubble is a gas medium that generates the evolution of a chemical mechanism governed by the internal bubble conditions. These gases are described by a state equation, linking the pressure to the volume, temperature and species amounts, and influencing simultaneously the dynamical, the thermal and the mass variation in the cavitation bubble...
September 2017: Ultrasonics Sonochemistry
Minh N Nguyen, Mohan R Pradhan, Chandra Verma, Pingyu Zhong
Summary: In this study, computational methods are applied to investigate the general properties of antigen engaging residues of a paratope from a non-redundant dataset of 403 antibody-antigen complexes to dissect the contribution of hydrogen bonds, hydrophobic, van der Waals contacts and ionic interactions, as well as role of water molecules in the antigen-antibody interface. Consistent with previous reports using smaller datasets, we found that Tyr, Trp, Ser, Asn, Asp, Thr, Arg, Gly, His contribute substantially to the interactions between antibody and antigen...
June 15, 2017: Bioinformatics
Hao Zhou, Chengzhang Wang, Tao Deng, Ran Tao, Wenjun Li
Three series of novel urushiol derivatives were designed by introducing a hydroxamic acid moiety into the tail of an alkyl side chain and substituents with differing electronic properties or steric bulk onto the benzene ring and alkyl side chain. The compounds' binding affinity towards HDAC8 was screened by Glide docking. The highest-scoring compounds were processed further with molecular docking, MD simulations and binding free energy studies to analyze the binding modes and mechanisms. Ten compounds had Glide scores of -8...
June 20, 2017: Journal of Biomolecular Structure & Dynamics
Li Yao, Xin Fang, Wei Gu, Wenhao Zhai, Yi Wan, Xixi Xie, Wanjin Xu, Xiaodong Pi, Guangzhao Ran, Guogang Qin
A new method to employ graphene as top electrode was introduced, and based on that, fully transparent quantum dot light emitting diodes (T-QLEDs) were sucessfully fabribated through a lamination process. We adopted the widely used wet transfer method to transfer bilayer graphene (BG) on polydimethylsiloxane/polyethylene terephthalate (PDMS/PET) substrate. The sheet resistance of graphene reduced to ~540 Ω/□ through transferring BG for 3 times on the PDMS/PET. The T-QLED has an inverted device structure of glass/Indium tin oxide (ITO)/ZnO nanoparticles (NPs)/(CdSSe/ZnS quantum dots (QDs))/ 1,1-bis[(di-4-tolylamino)phenyl] cyclohexane (TAPC)/MoO3/ graphene/PDMS/PET...
June 20, 2017: ACS Applied Materials & Interfaces
Bishwadeep Bagchi, Sushmita Sati, Vidyasagar Shilapuram
The Peng-Robinson equation of state with quadratic van der Waals (vdW) mixing rule model was chosen to perform the thermodynamic calculations in Flash3 column of Aspen Plus to predict the solubility of CO2 or any one of the hydrocarbons (HCs) among methane, ethane, propane, and butane in an ionic liquid 1-ethyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate ([emim][FAP]). Bubble point pressure, solubility, bubble point temperature, fugacity, and partial molar volume at infinite dilution were obtained from the simulations, and enthalpy of absorption, Gibbs free energy of solvation, and entropy change of absorption were estimated by thermodynamic relations...
June 19, 2017: Environmental Science and Pollution Research International
Rasim Mirzayev, Kimmo Mustonen, Mohammad R A Monazam, Andreas Mittelberger, Timothy J Pennycook, Clemens Mangler, Toma Susi, Jani Kotakoski, Jannik C Meyer
Two-dimensional (2D) materials have considerably expanded the field of materials science in the past decade. Even more recently, various 2D materials have been assembled into vertical van der Waals heterostacks, and it has been proposed to combine them with other low-dimensional structures to create new materials with hybridized properties. We demonstrate the first direct images of a suspended 0D/2D heterostructure that incorporates C60 molecules between two graphene layers in a buckyball sandwich structure...
June 2017: Science Advances
Jie Jiang, Yugandhar Bitla, Chun-Wei Huang, Thi Hien Do, Heng-Jui Liu, Ying-Hui Hsieh, Chun-Hao Ma, Chi-Yuan Jang, Yu-Hong Lai, Po-Wen Chiu, Wen-Wei Wu, Yi-Chun Chen, Yi-Chun Zhou, Ying-Hao Chu
We present a promising technology for nonvolatile flexible electronic devices: A direct fabrication of epitaxial lead zirconium titanate (PZT) on flexible mica substrate via van der Waals epitaxy. These single-crystalline flexible ferroelectric PZT films not only retain their performance, reliability, and thermal stability comparable to those on rigid counterparts in tests of nonvolatile memory elements but also exhibit remarkable mechanical properties with robust operation in bent states (bending radii down to 2...
June 2017: Science Advances
Alexander V Rudnev, Veerabhadrarao Kaliginedi, Andrea Droghetti, Hiroaki Ozawa, Akiyoshi Kuzume, Masa-Aki Haga, Peter Broekmann, Ivan Rungger
An open challenge for single-molecule electronics is to find stable contacts at room temperature with a well-defined conductance. Common coinage metal electrodes pose fabrication and operational problems due to the high mobility of the surface atoms. We demonstrate how molecules covalently grafted onto mechanically robust graphite/graphene substrates overcome these limitations. To this aim, we explore the effect of the anchoring group chemistry on the charge transport properties of graphite-molecule contacts by means of the scanning tunneling microscopy break-junction technique and ab initio simulations...
June 2017: Science Advances
Bridget Salna, Abdelkrim Benabbas, Douglas Russo, Paul M Champion
A proper description of proton donor-acceptor (D-A) distance fluctuations is crucial for understanding tunneling in proton-coupled electron transport (PCET). The typical harmonic approximation for the D-A potential results in a Gaussian probability distribution, which does not appropriately reflect the electronic repulsion forces that increase the energetic cost of sampling shorter D-A distances. Because these shorter distances are the primary channel for thermally activated tunneling, the analysis of tunneling kinetics depends sensitively on the inherently anharmonic nature of the D-A interaction...
June 19, 2017: Journal of Physical Chemistry. B
Zhansheng Lu, Peng Lv, Zongxian Yang, Shuo Li, Dongwei Ma, Ruqian Wu
Single atom catalysts (SACs) have attracted broad research interest in recent years due to their importance in various fields, such as environmental protection and energy conversion. Here, we discuss the mechanisms of CO oxidation to CO2 over single Ag atoms supported on hexagonal boron-nitride sheets (Ag1/BN) through systematic van der Waals inclusive density functional theory (DFT-D) calculations. The Ag adatom can be anchored onto a boron defect (VB), as suggested by the large energy barrier of 3.12 eV for Ag diffusion away from the VB site...
June 19, 2017: Physical Chemistry Chemical Physics: PCCP
Layla Filiciotto, Gustavo de Miguel, Alina M Balu, Antonio A Romero, Jan C van der Waal, Rafael Luque
Biomass conversion into chemicals, materials and fuels emerged in the past decade as the most promising alternative to the current petroleum-based industry. However, the chemocatalytic conversion of biomass and bio-derived sugars often leads to numerous side-products, such as humins. The limited characterization of humin materials restricts their study for possible future applications. Thus, herein photophysical studies on humins and separated humin fractions were carried out using steady-state and time-resolved fluorescence techniques...
June 19, 2017: Chemical Communications: Chem Comm
Yasutaka Enomoto, Yoko Imai, Kazuo Tajima
The present study investigates the adsorption of the three-phase emulsion on various solid/water interfaces. Vesicles can be used as emulsifiers in the three-phase emulsions and act as an independent phase unlike the surfactant used in conventional emulsions; therefore, it is expected that the three-phase emulsion formed by the adhesion of vesicles to the oil/water interface will adsorb on various solid/water interfaces. The cationic three-phase emulsion was prepared to encourage emulsion adsorption on negatively charged solid substrates in water...
June 13, 2017: Journal of Oleo Science
Manoj Ducher, Fabio Pietrucci, Etienne Balan, Guillaume Ferlat, Lorenzo Paulatto, Marc Blanchard
Many properties of aqueous cations depend on their coordination state. However, the lack of long-range order and the dynamic character of aqueous solutions make it difficult to obtain information beyond average coordination parameters. A thorough understanding of the molecular scale environment of aqueous cations usually requires a combination of experimental and theoretical approaches. In the case of Zn(2+), significant discrepancies occur among theoretical investigations based on first-principles molecular-dynamics (FPMD) or free-energy calculations, although experimental data consistently point to a dominant hexaaquo-zinc complex (Zn[H2O]6)(2+) in pure water...
June 16, 2017: Journal of Chemical Theory and Computation
João M P França, Carlos A Nieto de Castro, Agílio A H Pádua
We used molecular dynamics simulation to study the effect of suspended carbon nanomaterials, nanotubes and graphene sheets, on the thermal conductivity of ionic liquids, an issue related to understanding the properties of nanofluids. One important aspect that we developed is an atomistic model of the interactions between the organic ions and carbon nanomaterials, so we did not rely on existing force fields for small organic molecules or assume simple combining rules to describe the interactions at the liquid/material interface...
June 16, 2017: Physical Chemistry Chemical Physics: PCCP
Jamo Momand, Ruining Wang, Jos E Boschker, Marcel A Verheijen, Raffaella Calarco, Bart J Kooi
Phase-change materials based on GeSbTe show unique switchable optoelectronic properties and are an important contender for next-generation non-volatile memories. Moreover, they recently received considerable scientific interest, because it is found that a vacancy ordering process is responsible for both an electronic metal-insulator transition and a structural cubic-to-trigonal transition. GeTe-Sb2Te3 based superlattices, or specifically their interfaces, provide an interesting platform for the study of GeSbTe alloys...
June 16, 2017: Nanoscale
H Ghorbanfekr-Kalashami, K S Vasu, R R Nair, François M Peeters, M Neek-Amal
Van der Waals (vdW) interaction between two-dimensional crystals (2D) can trap substances in high pressurized (of order 1 GPa) on nanobubbles. Increasing the adhesion between the 2D crystals further enhances the pressure and can lead to a phase transition of the trapped material. We found that the shape of the nanobubble can depend critically on the properties of the trapped substance. In the absence of any residual strain in the top 2D crystal, flat nanobubbles can be formed by trapped long hydrocarbons (that is, hexadecane)...
June 16, 2017: Nature Communications
Rian J G Peters van Neijenhof, Erik van Duijn, Julia F Van Den Berg, Margot W M de Waal, Roos C van der Mast, Hannie C Comijs
Insomnia symptoms are highly prevalent in depressed older adults. This study investigates the association between hypothalamic-pituitary-adrenal (HPA) axis activity and symptoms of insomnia, respectively, sleep duration among 294 depressed and 123 non-depressed older adults of the Netherlands Study of Depression in Older people (NESDO) study. Insomnia symptoms were defined as clinically relevant when having a score ≥ 10 points on the Women's Health Initiative Insomnia Rating Scale (WHIIRS). Sleep duration was categorized in short (≤ 6 h per night), normal (7-8 h per night) and long (≥ 9 h per night) duration...
June 15, 2017: Journal of Sleep Research
Yunfang Li, Wei-Tao Lu, Hongjin Fu, Xiaolin Zhao, Shuqiong Xu
Molecular dynamics simulations demonstrate that several polyacetylene (PA) chains can encapsulate and self-assemble into multi-stranded helical structures in confined inner space of carbon nanotubes (SWCNT). The driving van der Waals force and curvature provided by tube wall enable polymers to bend and spiral to maximize the π-π stacking area with tube wall when filling inside SWCNT. Structural forms and knitting pattern of multiple helices are influenced by the combined effect of tube space, number of PA chains and temperature...
June 15, 2017: Nanotechnology
Clarisse Gravina Ricci, Bo Li, Li-Tien Cheng, Joachim Dzubiella, J Andrew McCammon
Solvation is a fundamental driving force in many biological processes including biomolecular recognition and self-assembly, not to mention protein folding, dynamics, and function. The Variational Implicit Solvent Method (VISM) is a theoretical tool currently developed and optimized to estimate solvation free energies for systems of very complex topology, such as biomolecules. VISM's theoretical framework makes it unique because it couples hydrophobic, van der Waals and electrostatic interactions as a functional of the solvation interface...
June 14, 2017: Journal of Physical Chemistry. B
Na Yeon Kim, Hu Young Jeong, Jung Hwa Kim, Gwangwoo Kim, Hyeon Suk Shin, Zonghoon Lee
Transition to a commensurate state changes the local symmetry periodicity on two-dimensional van der Waals superstructures, evoking distinctive properties far beyond individual layers. We investigate the morphology of moiré superstructures of graphene on hexagonal boron nitride (hBN) with a low twist angle (≈0°) through moiré fringe analyses with dark field transmission electron microscopy. The moiré fringes exhibit local variation, suggesting that the interaction between graphene and hBN depends on the stacking configuration and that local transition to the commensurate state occurs through the reduced crystalline mismatch (that is, by lattice stretching and twisting on the graphene lattices)...
June 14, 2017: ACS Nano
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"