keyword
MENU ▼
Read by QxMD icon Read
search

ATOM

keyword
https://www.readbyqxmd.com/read/28550607/dft-based-prediction-of-reactivity-of-short-chain-alcohol-dehydrogenase
#1
I Stawoska, A Dudzik, M Wasylewski, M Jemioła-Rzemińska, A Skoczowski, K Strzałka, M Szaleniec
The reaction mechanism of ketone reduction by short chain dehydrogenase/reductase, (S)-1-phenylethanol dehydrogenase from Aromatoleum aromaticum, was studied with DFT methods using cluster model approach. The characteristics of the hydride transfer process were investigated based on reaction of acetophenone and its eight structural analogues. The results confirmed previously suggested concomitant transfer of hydride from NADH to carbonyl C atom of the substrate with proton transfer from Tyr to carbonyl O atom...
May 26, 2017: Journal of Computer-aided Molecular Design
https://www.readbyqxmd.com/read/28550472/salt-induced-na-k-atpase-%C3%AE-%C3%AE-expression-involves-soluble-adenylyl-cyclase-in-endothelial-cells
#2
Mirja Mewes, Johanna Nedele, Katrin Schelleckes, Olga Bondareva, Malte Lenders, Kristina Kusche-Vihrog, Hans-Joachim Schnittler, Stefan-Martin Brand, Boris Schmitz, Eva Brand
High dietary salt intake may lead to vascular stiffness, which predicts cardiovascular diseases such as heart failure, and myocardial and cerebral infarctions as well as renal impairment. The vascular endothelium is a primary target for deleterious salt effects leading to dysfunction and endothelial stiffness. We hypothesize that the Ca(2+)- and bicarbonate-activated soluble adenylyl cyclase (sAC) contributes to Na(+)/K(+)-ATPase expression regulation in vascular endothelial cells and is an important regulator of endothelial stiffness...
May 26, 2017: Pflügers Archiv: European Journal of Physiology
https://www.readbyqxmd.com/read/28550376/development-of-an-amber-compatible-transferable-force-field-for-poly-ethylene-glycol-ethers-glymes
#3
Nathalia S V Barbosa, Yong Zhang, Eduardo R A Lima, Frederico W Tavares, Edward J Maginn
An all-atom force field consistent with the general AMBER force field (GAFF) format for poly(ethylene glycol) dimethyl ether (diglyme or G2) was developed by fitting to experimental liquid densities and dielectric constants. Not surprisingly, the new force field gives excellent agreement with experimental liquid phase densities and dielectric constants over a wide temperature range. Other dynamic and thermodynamic properties of liquid G2 such as its self-diffusion coefficient, shear viscosity, and vaporization enthalpy were also calculated and compared to experimental data...
June 2017: Journal of Molecular Modeling
https://www.readbyqxmd.com/read/28550312/dependence-of-solidification-for-bi2te3-xsex-alloys-on-their-liquid-states
#4
Yuan Yu, Zhan Wu, Oana Cojocaru-Mirédin, Bin Zhu, Xiao-Yu Wang, Na Gao, Zhong-Yue Huang, Fang-Qiu Zu
The resistivity versus temperature (ρ-T) behaviours of liquid n-type Bi2Te3-x Se x (x = 0.3, 0.45 and 0.6) alloys are explored up to 1050 °C. A clear hump is observed on all ρ-T curves of the three studied Bi2Te3-x Se x melts during the heating process, which suggests that a temperature-induced liquid-liquid structural transition takes place in the melts. Based on this information, the solidification behaviours and microstructures of the alloys with different liquid states are investigated. The samples that experienced liquid structural transition show that the nucleation and growth undercooling degrees are conspicuously enlarged and the solidification time is shortened...
May 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28550291/atomic-layer-etching-of-graphene-through-controlled-ion-beam-for-graphene-based-electronics
#5
Ki Seok Kim, You Jin Ji, Yeonsig Nam, Ki Hyun Kim, Eric Singh, Jin Yong Lee, Geun Young Yeom
The electronic and optical properties of graphene are greatly dependent on the the number of layers. For the precise control of the graphene layers, atomic layer etching (ALE), a cyclic etching method achieved through chemical adsorption and physical desorption, can be the most powerful technique due to barely no damage and no contamination. In this study, we demonstrated the ALE process of graphene layers without noticeably damaging the graphene by using a controlled low energy oxygen (O2(+)/O(+))-ion for chemical adsorption and a low energy Ar(+)-ion (11...
May 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28550280/doping-of-metal-organic-frameworks-towards-resistive-sensing
#6
Hidetsugu Shiozawa, Bernhard C Bayer, Herwig Peterlik, Jannik C Meyer, Wolfgang Lang, Thomas Pichler
Coordination polymerization leads to various metal-organic frameworks (MOFs) with unique physical properties and chemical functionalities. One of the challenges towards their applications as porous materials is to make MOFs optimally conductive to be used as electronic components. Here, it is demonstrated that Co-MOF-74, a honeycomb nano-framework with one-dimensionally arranged cobalt atoms, advances its physical properties by accommodating tetracyanochinodimethan (TCNQ), an acceptor molecule. Strong intermolecular charge transfer reduces the optical band gap down to 1...
May 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28550000/reversal-of-%C3%AE-oxidative-pathways-for-the-microbial-production-of-chemicals-and-polymer-building-blocks
#7
REVIEW
Nicolai Kallscheuer, Tino Polen, Michael Bott, Jan Marienhagen
β-Oxidation is the ubiquitous metabolic strategy to break down fatty acids. In the course of this four-step process, two carbon atoms are liberated per cycle from the fatty acid chain in the form of acetyl-CoA. However, typical β-oxidative strategies are not restricted to monocarboxylic (fatty) acid degradation only, but can also be involved in the utilization of aromatic compounds, amino acids and dicarboxylic acids. Each enzymatic step of a typical β-oxidation cycle is reversible, offering the possibility to also take advantage of reversed metabolic pathways for applied purposes...
May 23, 2017: Metabolic Engineering
https://www.readbyqxmd.com/read/28549974/evaluation-of-tacrolimus-sorption-to-pvc-and-non-pvc-based-tubes-in-administration-sets-pump-method-vs-drip-method
#8
Su-Eon Jin, Seungho Jeon, Hyo-Jin Byon, Sung-Joo Hwang
Tacrolimus sorption to tubes was evaluated using pump and drip methods For tubes, polyvinylchloride (PVC)- and non-PVC-based (polyurethane [PU] and polyolefin [PO]) tubes were used. First, inner surface properties of tubes were analyzed using field emission scanning electron microscopy and X-ray photoelectron spectroscopy. Tacrolimus was quantitatively analyzed using high-performance liquid chromatography with UV detection. For kinetic sorption analysis, diluted tacrolimus to 10μg/mL was passed through 1-m-long tubes at 10mL/h...
May 23, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28549727/topographic-analysis-by-atomic-force-microscopy-of-proteoliposomes-matrix-vesicle-mimetics-harboring-tnap-and-anxa5
#9
Maytê Bolean, Ivana A Borin, Ana M S Simão, Massimo Bottini, Luis A Bagatolli, Marc F Hoylaerts, José L Millán, Pietro Ciancaglini
Atomic force microscopy (AFM) is one of the most commonly used scanning probe microscopy techniques for nanoscale imaging and characterization of lipid-based particles. However, obtaining images of such particles using AFM is still a challenge. The present study extends the capabilities of AFM to the characterization of proteoliposomes, a special class of liposomes composed of lipids and proteins, mimicking matrix vesicles (MVs) involved in the biomineralization process. To this end, proteoliposomes were synthesized, composed of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1,2-dipalmitoyl-sn-glycero-3-phospho-L-serine (DPPS), with inserted tissue-nonspecific alkaline phosphatase (TNAP) and/or annexin V (AnxA5), both characteristic proteins of osteoblast-derived MVs...
May 23, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28549375/interfacial-electrical-and-band-alignment-characteristics-of-hfo2-ge-stacks-with-in-situ-formed-sio2-interlayer-by-plasma-enhanced-atomic-layer-deposition
#10
Yan-Qiang Cao, Bing Wu, Di Wu, Ai-Dong Li
In situ-formed SiO2 was introduced into HfO2 gate dielectrics on Ge substrate as interlayer by plasma-enhanced atomic layer deposition (PEALD). The interfacial, electrical, and band alignment characteristics of the HfO2/SiO2 high-k gate dielectric stacks on Ge have been well investigated. It has been demonstrated that Si-O-Ge interlayer is formed on Ge surface during the in situ PEALD SiO2 deposition process. This interlayer shows fantastic thermal stability during annealing without obvious Hf-silicates formation...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28548908/effect-of-end-segment-on-physicochemical-properties-and-platelet-compatibility-of-poly-propylene-glycol-initiated-poly-methyl-methacrylate
#11
Chihiro Fukuda, Chie Yahata, Takuya Kinoshita, Takafumi Watanabe, Hideo Tsukamoto, Akira Mochizuki
It is well known that polyether-based copolymers have good blood compatibility, although many mechanisms have been proposed to explain their favorable performance. Our objective in carrying out the present study was to obtain a better understanding of the effect of the (poly)ether segment on blood compatibility. Therefore, we synthesized poly(propylene glycol) (PPG)-based initiators for atom transfer polymerization, where the number of propylene glycol (PG) units in the PPG (Pn(PG) was varied from 1 to 94. Methyl methacrylate (MMA) was polymerized using the initiators, resulting in the formation of polyMMAs with a PG-based ether part at the polymer terminal...
May 26, 2017: Journal of Biomaterials Science. Polymer Edition
https://www.readbyqxmd.com/read/28548860/direct-imaging-of-kinetic-pathways-of-atomic-diffusion-in-monolayer-molybdenum-disulfide
#12
Jinhua Hong, Yuhao Pan, Zhixin Hu, Danhui Lv, Chuanhong Jin, Wei Ji, Jun Yuan, Ze Zhang
Direct observation of atomic migration both on and below surfaces is a long-standing but important challenge in materials science as diffusion is one of the most elementary processes essential to many vital material behaviors. Probing the kinetic pathways, including metastable or even transition states involved down to atomic scale, holds the key to the underlying physical mechanisms. Here, we applied aberration-corrected transmission electron microscopy (TEM) to demon-strate direct atomic-scale imaging and quasi-real-time tracking of diffusion of Mo adatoms and vacancies in monolayer MoS2, an important 2D transition metal dichalcogenide (TMD) system...
May 26, 2017: Nano Letters
https://www.readbyqxmd.com/read/28548842/engineering-the-composition-and-structure-of-bimetallic-au-cu-alloy-nanoparticles-in-carbon-nanofibers-self-supported-electrode-materials-for-electrocatalytic-water-splitting
#13
Juan Wang, Han Zhu, Danni Yu, JiaWei Chen, JiaDong Chen, Ming Zhang, LiNa Wang, MingLiang Du
The bimetallic Au-Cu alloy nanoparticles have been constructed in electrospun carbon nanofibers (Au-Cu/CNFs), employing as high efficient hydrogen evolution reaction (HER) electrode. The morphology, structure and composition of bimetallic Au-Cu alloy can be controlled by adjusting the precursor nanofibers through a facile approach. With the increased Cu contents, the Au-Cu alloy have a transition from homogenous AuCu3 alloy phase to Au3Cu phase with Cu shell. The self-supported bimetallic Au-Cu/CNFs hybrid can be directly employed as electrodes materials for water splitting and it showed excellent electrochemical activity, including long-term stability, high exchange current density and low overpotential...
May 26, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28548839/structural-distortions-and-charge-density-waves-in-iodine-chains-encapsulated-inside-carbon-nanotubes
#14
Hannu-Pekka Komsa, Ryosuke Senga, Kazutomo Suenaga, Arkady V Krasheninnikov
Atomic chains are perfect systems for getting fundamental insights into the electron dynamics and coupling between the electronic and ionic degrees of freedom in one dimensional metals. Depending on the band filling, they can exhibit Peierls instabilities (or charge density waves), where equally spaced chain of atoms with partially filled band is inherently unstable, exhibiting spontaneous distortion of the lattice that further leads to metal-insulator transition in the system. Here, using high-resolution scanning transmission electron microscopy, we directly image the atomic structures of a chain of iodine atoms confined inside carbon nanotubes...
May 26, 2017: Nano Letters
https://www.readbyqxmd.com/read/28548837/the-role-of-the-hydroxyl-group-in-propofol-protein-target-recognition-insights-from-oniom-studies
#15
Ling Qiu, Jianguo Lin, Qingzhu Liu, Shanshan Wang, Gaochao Lv, Ke Li, Haiming Shi, Zhengkun Huang, Edward J Bertaccini
Propofol (PFL, 1-hydroxyl-2,6-diisopropylbenzene) is currently used widely as one of the most well-known intravenous anesthetics to relieve surgical suffering, but its mechanism of action is not yet clear. Previous experimental studies have demonstrated that the hydroxyl group of PFL plays a dominant role in the molecular recognition of PFL with receptors that lead to hypnosis. To further explore the mechanism of anesthesia induced by PFL in the present work, the exact binding features and interaction details of PFL with three important proteins, human serum albumin (HSA), the pH-gated ion channel from Gloeobacter violaceus (GLIC) and horse spleen apoferritin (HSAF), were investigated systematically by using a rigorous three-layer ONIOM(M06-2X/6-31+G*:PM6:AMBER) method...
May 26, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28548829/fused-pentagon-configuration-dependent-electron-transfer-of-monotitanium-encapsulated-fullerenes
#16
Jing-Shuang Dang, Wei-Wei Wang, Jia-Jia Zheng, Xiang Zhao, Shigeru Nagase
We introduce monotitanium-based endohedral metallofullerenes (EMFs) using density functional theory calculations. Isomeric C64 fullerenes are initially employed as hosts, and Ti@C64 species show novel features on the electronic structures. Energetically, the preference of titanium residing on triple-fused-pentagon subunits is proposed in theory. More importantly, different from current knowledge on mono-EMFs, electron transfer between titanium and carbon cages is not unified but is essentially dependent on the pentagon distribution of the binding sites, giving rise to variations of the cationic titanium of Ti@C64...
May 26, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28548819/tuning-the-properties-of-polymer-capsules-for-cellular-interactions
#17
Huanli Sun, Jiwei Cui, Yi Ju, Xi Chen, Edgar H H Wong, Jenny Tran, Greg G Qiao, Frank Caruso
Particle-cell interactions are governed by, among other factors, the composition and surface properties of the particles. Herein, we report the preparation of various polymer capsules with different compositions and properties via atom transfer radical polymerization mediated continuous assembly of polymers (CAPATRP), where the cellular interactions of these capsules, particularly fouling and specific targeting, are examined by flow cytometry and deconvolution microscopy. Acrylated eight-arm poly(ethylene glycol) (8-PEG) and poly(N-(2-hydroxypropyl)-methacrylamide) (PHPMA) as well as methacrylated hyaluronic acid (HA), poly(glutamic acid) (PGA), and poly(methacrylic acid) (PMA) are used as macro-cross-linkers to obtain a range of polymer capsules with different compositions (PEG, PHPMA, HA, PGA, and PMA)...
May 26, 2017: Bioconjugate Chemistry
https://www.readbyqxmd.com/read/28548677/destabilization-of-human-insulin-fibrils-by-peptides-of-fruit-bromelain-derived-from-ananas-comosus-pineapple
#18
Sromona Das, Debasish Bhattacharyya
Deposition of insulin aggregates in human body leads to dysfunctioning of several organs. Effectiveness of fruit bromelain from pineapple in prevention of insulin aggregate was investigated. Proteolyses of bromelain was done as par human digestive system and the pool of small peptides was separated from larger peptides and proteins. Under conditions of growth of insulin aggregates from its monomers, this pool of peptides restricted the reaction upto formation of oligomers of limited size. These peptides also destabilized preformed insulin aggregates to oligomers...
May 26, 2017: Journal of Cellular Biochemistry
https://www.readbyqxmd.com/read/28548674/how-silver-segregation-stabilizes-1d-surface-gold-oxide-a-cluster-expansion-study-combined-with-ab-initio-md-simulations
#19
Sandra Hoppe, Yong Li, Lyudmila V Moskaleva, Stefan Müller
Gold has many unique properties, some of which continue to be uncovered, such as the rich chemistry of gold at the nanoscale. In this study, gold surprises us again by the unusual stability of one-dimensional gold oxide structures on the surface of gold, which enhances in the presence of silver impurities. We employ first-principles calculations to investigate the surface segregation of silver in the presence of atomic-oxygen adsorbates arranged in chains on the Au(321) surface. Such 1D oxide chains have previously been suggested as the most stable form of adsorbed oxygen on gold...
May 26, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28548672/complex-magnetic-orders-in-small-cobalt-benzene-molecules
#20
J W González, T Alonso-Lanza, F Delgado, F Aguilera-Granja, A Ayuela
Organometallic clusters based on transition metal atoms are interesting because of their possible applications in spintronics and quantum information processing. In addition to the enhanced magnetism at the nanoscale, the organic ligands may provide a natural shield against unwanted magnetic interactions with the matrices required for applications. Here we show that the organic ligands may lead to non-collinear magnetic order as well as the expected quenching of the magnetic moments. We use different density functional theory (DFT) methods to study the experimentally relevant three cobalt atoms surrounded by benzene rings (Co3Bz3)...
May 26, 2017: Physical Chemistry Chemical Physics: PCCP
keyword
keyword
62445
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"