keyword
MENU ▼
Read by QxMD icon Read
search

Van der Waals

keyword
https://www.readbyqxmd.com/read/28106462/stripe-and-short-range-order-in-the-charge-density-wave-of-1t-cu_-x-tise_-2
#1
A M Novello, M Spera, A Scarfato, A Ubaldini, E Giannini, D R Bowler, Ch Renner
We study the impact of Cu intercalation on the charge density wave (CDW) in 1T-Cu_{x}TiSe_{2} by scanning tunneling microscopy and spectroscopy. Cu atoms, identified through density functional theory modeling, are found to intercalate randomly on the octahedral site in the van der Waals gap and to dope delocalized electrons near the Fermi level. While the CDW modulation period does not depend on Cu content, we observe the formation of charge stripe domains at low Cu content (x<0.02) and a breaking up of the commensurate order into 2×2 domains at higher Cu content...
January 6, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28106436/transient-casimir-forces-from-quenches-in-thermal-and-active-matter
#2
Christian M Rohwer, Mehran Kardar, Matthias Krüger
We compute fluctuation-induced (Casimir) forces for classical systems after a temperature quench. Using a generic coarse-grained model for fluctuations of a conserved density, we find that transient forces arise even if the initial and final states are force free. In setups reminiscent of Casimir (planar walls) and van der Waals (small inclusions) interactions, we find comparable exact universal expressions for the force. Dynamical details only scale the time axis of transient force curves. We propose that such quenches can be achieved, for instance, in experiments on active matter, employing tunable activity or interaction protocols...
January 6, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28106222/digestibility-and-supramolecular-structural-changes-of-maize-starch-by-non-covalent-interactions-with-gallic-acid
#3
Chengdeng Chi, Xiaoxi Li, Yiping Zhang, Ling Chen, Lin Li, Zhijiang Wang
The effects of non-covalent interactions between gallic acid (GA) and starch on starch digestibility and supramolecular structural changes (short-range ordered molecular structure, crystalline structure, lamellar structure and fractal structure) were investigated. The results indicated that the digestibility of both starches was substantially reduced in the rapidly digestible starch (RDS) content, but resistant starch (RS) was increased after interacting with GA. The RS content of starch-GA complexes ranged from 17...
January 20, 2017: Food & Function
https://www.readbyqxmd.com/read/28106187/layer-separable-and-gap-tunable-topological-insulators
#4
Kai-Wei Chang, Wei Ji, Chao-Cheng Kaun
The way in which states of a topological insulator (TI) transform from monolayer to bulk is an important issue for applications in spintronics. However, unlike graphite, most layered materials are difficult to exfoliate. Using first-principles calculations, we predict that thallium selenide (TlSe) will be a layered TI with rather weak interlayer coupling and thus it should be exfoliated easily. The evolution of the topological states can also be driven by doping with indium (In) atoms or applying lateral strains...
January 20, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28104368/interaction-of-capsaicin-with-calf-thymus-dna-a-multi-spectroscopic-and-molecular-modelling-study
#5
Faizan Abul Qais, K M Abdullah, Md Maroof Alam, Imrana Naseem, Iqbal Ahmad
Studying the mode of interaction between small molecules and DNA have received much attention in recent years, as many drugs have been reported to directly interact with DNA thereby regulating the expression of many genes. Capsaicin is a capsaiciniods family phytocompound having many therapeutic applications including diabetic neuropathy, rheumatoid arthritis, prevention of DNA strand breaks and chromosomal aberrations. In this study, we have investigated the interaction of capsaicin with calf thymus DNA using a number of biophysical techniques to get an insight and better understanding of the interaction mechanism...
January 16, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28103669/reaxff-reactive-force-field-study-of-molybdenum-disulfide-mos2
#6
Alireza Ostadhossein, Ali Rahnamoun, Yuanxi Wang, Peng Zhao, Sulin Zhang, Vincent H Crespi, Adri C T van Duin
Two dimensional (2D) layers of molybdenum disulfide, MoS2, have been recognized as promising materials for nano-electronics due to their exceptional electronic and optical properties. Here we develop a new ReaxFF reactive potential which can accurately describe the thermodynamic and structural properties of MoS2 sheets, guided by extensive density functional theory (DFT) simulations. This potential is then applied to the formation energies of five different types of vacancies, various vacancy migration barriers, and the transition barrier between the semiconducting 2H and metallic 1T phases...
January 20, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28101950/molecular-binding-of-toxic-phenothiazinium-derivatives-azures-to-bovine-serum-albumin-a-comparative-spectroscopic-calorimetric-and-in-silico-study
#7
Somnath Das, Md Maidul Islam, Gopal Chandra Jana, Anirudha Patra, Pradeep K Jha, Maidul Hossain
In this paper, the comparative binding behavior of antimalarial drug azure A, azure B and azure C with bovine serum albumin (BSA) has been studied. The interaction has been confirmed by multispectroscopic (UV, fluorescence, Fourier transform infrared (FT-IR), and circular dichroism) and molecular docking techniques. The experimental results show that azure B has the highest BSA binding affinity followed by azure A and azure C. The experimental evidence of binding showed a static quenching mechanism in the interaction azures with BSA...
January 19, 2017: Journal of Molecular Recognition: JMR
https://www.readbyqxmd.com/read/28101708/characterization-of-interaction-between-amino-acids-and-fulvic-like-organic-matter-by-fluorescence-spectroscopy-combining-thermodynamic-calculation
#8
Tao Lin, Bingwei Hou, Jian Wang, Yaqun Xu, Wei Chen
Dissolved organic matter (DOM), as a very fine colloidal suspension, could inevitably affect the transformation process of dissolved organic nitrogen (DON) in drinking water treatment. Tryptophan and tyrosine were used as representatives of DON to investigate the interactions between amino acids and fulvic-like components of fluorescent DOM using titration experiments. The fluorescence intensity decreased significantly with the increasing fulvic acid (FA) concentration, suggesting that FA could greatly quench the intrinsic fluorescence of amino acids such as tryptophan and tyrosine...
January 18, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28099026/unimer-assisted-exfoliation-for-high-concentrated-aqueous-dispersion-solutions-of-single-and-few-layered-van-der-waals-materials
#9
Changbong Yeon, Inyeal Lee, Gil-Ho Kim, Sun Jin Yun
We suggest unimer-assisted exfoliation method for the exfoliation of Van der Waals two-dimensional (2D) materials such as graphene, MoS2, and h-BN, and show that the micellar size is a critical parameter for enhancing the exfoliation efficiency. To explain the effectiveness of the unimers on the exfoliation, the influence of micellar size of a biocompatible block copolymer, Pluronic F-68, is evaluated in view of the yield and thickness of exfoliated 2D flakes. By the addition of water-soluble alcohols, the surfactants exist in the form of unimer, which facilitates the intercalation into the layered materials and their exfoliation...
January 18, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28098447/the-stories-tryptophans-tell-exploring-protein-dynamics-of-heptosyltransferase-i-from-escherichia-coli
#10
Joy M Cote, Carlos Andres Ramirez-Mondragon, Zarek S Siegel, Daniel Joseph Czyzyk, Jiali Gao, Yuk Yin Sham, Ishita Mukerji, Erika A Taylor
Heptosyltransferase I (HepI) catalyzes the addition of a single L-glycero-β-D-manno-heptose sugar (heptose) onto the membrane incorporated Kdo2-Lipid A as part of the biosynthesis of the core region of lipopolysaccharide (LPS). Gram-negative bacteria with gene knockouts of HepI have reduced virulence with enhanced susceptibility to hydrophobic antibiotics, making design of inhibitors against HepI of interest. Previous studies have shown that HepI protein dynamics are partially rate limiting, and therefore disruption of protein dynamics might provide a new strategy for inhibiting HepI...
January 18, 2017: Biochemistry
https://www.readbyqxmd.com/read/28098209/crystal-growth-of-dirac-semimetal-zrsis-with-high-magnetoresistance-and-mobility
#11
Raman Sankar, G Peramaiyan, I Panneer Muthuselvam, Christopher J Butler, Klauss Dimitri, Madhab Neupane, G Narsinga Rao, M-T Lin, F C Chou
High quality single crystal ZrSiS as a theoretically predicted Dirac semimetal has been grown successfully using a vapor phase transport method. The single crystals of tetragonal structure are easy to cleave into perfect square-shaped pieces due to the van der Waals bonding between the sulfur atoms of the quintuple layers. Physical property measurement results including resistivity, Hall coefficient (RH), and specific heat are reported. The transport and thermodynamic properties suggest a Fermi liquid behavior with two Fermi pockets at low temperatures...
January 18, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28097692/structural-role-of-a-conserved-active-site-cis-proline-in-the-thermotoga-maritima-acetyl-esterase-from-the-carbohydrate-esterase-family-7
#12
Mrityunjay K Singh, Narayanan Manoj
A conserved cis proline residue located in the active site of Thermotoga maritima acetyl esterase (TmAcE) from the carbohydrate esterase family 7 (CE7) has been substituted by alanine. The residue was known to play a crucial role in determining the catalytic properties of the enzyme. To elucidate the structural role of the residue, the crystal structure of the Pro228Ala variant (TmAcEP228A ) was determined at 2.1 Å resolution. The replacement does not affect the overall secondary, tertiary and quaternary structures and moderately decreases the thermal stability...
January 18, 2017: Proteins
https://www.readbyqxmd.com/read/28097462/thermally-stable-schiff-base-and-its-metal-complexes-molecular-docking-and-protein-binding-studies
#13
Umran Duru Kamaci, Musa Kamaci, Aysegul Peksel
In this paper, interaction of Schiff base and its metal complexes carrying naphthalene ring in the structure with bovine serum albumin (BSA) were investigated using UV-vis absorption, fluorescence spectroscopies and molecular docking methods. The effect on the binding mechanism and properties of these compounds containing metal-free, iron and copper ions were also investigated. The fluorescence spectroscopy results showed that fluorescence intensity of BSA in the presence of different concentration of ligands was decreased through a static quenching mechanism...
January 18, 2017: Journal of Fluorescence
https://www.readbyqxmd.com/read/28096330/spectroscopic-evidence-for-bulk-band-inversion-and-three-dimensional-massive-dirac-fermions-in-zrte5
#14
Zhi-Guo Chen, R Y Chen, R D Zhong, John Schneeloch, C Zhang, Y Huang, Fanming Qu, Rui Yu, Q Li, G D Gu, N L Wang
Three-dimensional topological insulators (3D TIs) represent states of quantum matters in which surface states are protected by time-reversal symmetry and an inversion occurs between bulk conduction and valence bands. However, the bulk-band inversion, which is intimately tied to the topologically nontrivial nature of 3D Tis, has rarely been investigated by experiments. Besides, 3D massive Dirac fermions with nearly linear band dispersions were seldom observed in TIs. Recently, a van der Waals crystal, ZrTe5, was theoretically predicted to be a TI...
January 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28094971/predicting-nanoscale-dynamics-of-a-glass-forming-liquid-from-its-macroscopic-bulk-behavior-and-vice-versa
#15
Karolina Adrjanowicz, Kamil Kaminski, Magdalena Tarnacka, Grzegorz Szklarz, Marian Paluch
The properties of a molecular liquid confined at the nanometer length scale can be very much distinct from the bulk. For that reason, the macro- and the nanoscopic behaviors of glass-forming liquids are regarded as two non-connected realms, governed by their own rules. Here, we show that the glassy dynamics in molecular liquids confined to nanometer pores might obey the density scaling relation, /T, just like in bulk fluids. Even more surprisingly, the same value of the scaling exponent  superposes the -relaxation time measured at different state points in nanoscale confinement and on increased pressure...
January 17, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28094374/combined-in-and-ex-situ-studies-of-pyrazine-adsorption-into-the-aliphatic-mof-al-cau-13-structures-dynamics-and-correlations
#16
Helge Reinsch, Jannik Benecke, Martin Etter, Niclas Heidenreich, Norbert Stock
The intercalation of different pyrazines (pyrazine, methylpyrazine, 2,5-dimethylpyrazine, 2,3-dimethylpyrazine, trimethylpyrazine and tetramethylpyrazine) into the trans-1,4-cyclohexanedicarboxylate (CDC(2-)) based Al-MOF [Al(OH)(CDC)], denoted as CAU-13, was investigated. The adsorption of the guest molecules into the flexible MOF was carried out from an aqueous solution or via vapour phase adsorption, starting with the hydrated narrow-pore form of the framework [Al(OH)(O2C-C6H10-CO2)]·H2O (CAU-13-np). The obtained host-guest systems were characterised by thermogravimetry and vibrational spectroscopy and their crystal structures were elucidated using powder X-ray diffraction (PXRD) data...
January 17, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28094372/theoretical-studies-on-fgfr-isoform-selectivity-of-fgfr1-fgfr4-inhibitors-by-molecular-dynamics-simulations-and-free-energy-calculations
#17
Weitao Fu, Lingfeng Chen, Zhe Wang, Yanting Kang, Chao Wu, Qinqin Xia, Zhiguo Liu, Jianmin Zhou, Guang Liang, Yuepiao Cai
The activation and overexpression of fibroblast growth factor receptors (FGFRs) are highly correlated with a variety of cancers. Most small molecule inhibitors of FGFRs selectively target FGFR1-3, but not FGFR4. Hence, designing highly selective inhibitors towards FGFR4 remains a great challenge because FGFR4 and FGFR1 have a high sequence identity. Recently, two small molecule inhibitors of FGFRs, ponatinib and AZD4547, have attracted huge attention. Ponatinib, a type II inhibitor, has high affinity towards FGFR1/4 isoforms, but AZD4547, a type I inhibitor of FGFR1, displays much reduced inhibition toward FGFR4...
January 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28094253/dynamical-importance-of-van-der-waals-saddle-and-excited-potential-surface-in-c-1-d-d2-complex-forming-reaction
#18
Zhitao Shen, Haitao Ma, Chunfang Zhang, Mingkai Fu, Yanan Wu, Wensheng Bian, Jianwei Cao
Encouraged by recent advances in revealing significant effects of van der Waals wells on reaction dynamics, many people assume that van der Waals wells are inevitable in chemical reactions. Here we find that the weak long-range forces cause van der Waals saddles in the prototypical C((1)D)+D2 complex-forming reaction that have very different dynamical effects from van der Waals wells at low collision energies. Accurate quantum dynamics calculations on our highly accurate ab initio potential energy surfaces with van der Waals saddles yield cross-sections in close agreement with crossed-beam experiments, whereas the same calculations on an earlier surface with van der Waals wells produce much smaller cross-sections at low energies...
January 17, 2017: Nature Communications
https://www.readbyqxmd.com/read/28090811/antibacterial-combination-therapy-using-co-3-cu-2-zn-2-and-pd-2-complexes-their-calf-thymus-dna-binding-studies
#19
Fatemeh Khosravi, Hassan Mansouri-Torshizi
Four Co(III)-, Cu(II)-, Zn(II)- and Pd(II)- based potent antibacterial complexes of formula K3[Co(ox)3].3H2O (I), [Cu(bpy)2Cl]Cl.5H2O (II), [Zn(bpy)3]Cl2 (III) and [Pd(bpy)2](NO3)2 (IV) (where ox is oxalate and bpy is 2,2'-bipyridine) were synthesized. They were characterized by elemental analyses, molar conductance measurements, UV-Vis, FT-IR, (1)H NMR and (13)C NMR spectra. These metal complexes were ordered in three combination series of I+II, I+II+III and I+II+III+IV. Antibacterial activity was tested for each of these four metal complexes and their combinations against gram positive and gram negative bacteria...
January 16, 2017: Journal of Biomolecular Structure & Dynamics
https://www.readbyqxmd.com/read/28081101/design-of-many-body-spin-states-of-rydberg-atoms-excited-to-highly-tunable-magnetic-sublevels
#20
Svetlana A Malinovskaya
Quantum control methodology is presented to design many-body spin states in a spin chain of Rydberg atoms using laser pulses and a magnetic field. A two-photon ladder-type configuration is implemented, which is advantageous due to the combined action of the one-photon and two-photon detunings as control parameters. Many-body spin states are designed consisting of an ensemble of spins encoded in sublevels of Rydberg states and coupled via the van der Waals interactions.
January 15, 2017: Optics Letters
keyword
keyword
59676
1
2
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"