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https://www.readbyqxmd.com/read/28535340/optical-binding-of-nanowires
#1
Stephen H Simpson, Pavel Zemanek, Onofrio M Marago, Philip H Jones, Simon Hanna
Multiple scattering of light induces structured interactions, or optical binding forces, between collections of small particles. This has been extensively studied in the case of micro-spheres. However, binding forces are strongly shape dependent: here, we turn our attention to dielectric nanowires. Using a novel numerical model we uncover rich behaviour. The extreme geometry of the nanowires produces a sequence of stationary and dynamic states. In linearly polarized light, thermally stable ladder-like structures emerge...
May 23, 2017: Nano Letters
https://www.readbyqxmd.com/read/28534908/phase-evolution-of-lithium-intercalation-dynamics-in-2h-mos2
#2
Juan Xia, Jin Wang, Dongliang Chao, Zhen Chen, Zheng Liu, Jer-Lai Kuo, Jiaxu Yan, Ze Xiang Shen
Due to the easy intralayer gliding and weak interlayer van der Waals interaction in transition metal dichalcogenides (TMDs), ion (particularly Li(+)) intercalation has been used to modify and tune their atomic structures to obtain the desired optical, electronic and chemical properties for future optoelectronics and energy storage applications. A good understanding of the transformative structures during intercalation is critical. In this paper, we investigate the structural transformation dynamics of 2H-MoS2 using electrochemical Li(+) intercalation for 2H-MoS2...
May 23, 2017: Nanoscale
https://www.readbyqxmd.com/read/28534897/seed-mediated-co-reduction-in-a-large-lattice-mismatch-system-synthesis-of-pd-cu-nanostructures
#3
Meredith R Kunz, Sophia M McClain, Dennis P Chen, Kallum M Koczkur, Rebecca G Weiner, Sara E Skrabalak
Metal nanoparticles (NPs) are of interest for applications in catalysis, electronics, chemical sensing, and more. Their utility is dictated by their composition and physical parameters such as particle size, particle shape, and overall architecture (e.g., hollow vs. solid). Interestingly, the addition of a second metal to create bimetallic NPs adds multifunctionality, with new emergent properties common. However, synthesizing structurally defined bimetallic NPs remains a great challenge. One synthetic pathway to architecturally controlled bimetallic NPs is seed-mediated co-reduction (SMCR) in which two metal precursors are simultaneously co-reduced to deposit metal onto shape-controlled metal seeds, which direct the overgrowth...
May 23, 2017: Nanoscale
https://www.readbyqxmd.com/read/28534627/highly-stable-and-regenerative-metal-organic-framework-designed-by-multi-walled-divider-installation-strategy-for-detection-of-co-%C3%AE-%C3%AE-ions-and-organic-aromatics-in-water
#4
Kai Xing, Ruiqing Fan, Jiaqi Wang, Siqi Zhang, Kai Feng, Xi Du, Yang Song, Ping Wang, Yulin Yang
MOF-based sensors capable of effectively and stably detecting toxic species in water have attracted huge attention in terms of improving environmental monitoring levels and water quality. Combining the flexibility of structure and modifying of pore surface, a multi-walled divider installation (MWDI) strategy is proposed and used for property enhancement. We herein report three metal-organic frameworks (MOFs) 1-3 based on a C3 symmetry organic phosphonic ligand with topology increased from 3,6-connected to 3,8-connected...
May 23, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28534404/competing-gap-opening-mechanisms-of-monolayer-graphene-and-graphene-nanoribbons-on-strong-topological-insulators
#5
Zhuonan Lin, Wei Qin, Jiang Zeng, Wei Chen, Ping Cui, Jun-Hyung Cho, Zhenhua Qiao, Zhenyu Zhang
Graphene is a promising material for designing next-generation electronic and valleytronic devices, which often demand the opening of a bandgap in the otherwise gapless pristine graphene. To date, several conceptually different mechanisms have been extensively exploited to induce bandgaps in graphene, including spin-orbit coupling and inversion symmetry breaking for monolayer graphene, and quantum confinement for graphene nanoribbons (GNRs). Here, we present a multiscale study of the competing gap opening mechanisms in a graphene overlayer and GNRs proximity-coupled to topological insulators (TIs)...
May 23, 2017: Nano Letters
https://www.readbyqxmd.com/read/28534298/formulation-and-in-vitro-characterization-of-bioactive-mesoporous-silica-with-doxorubicin-and-metronidazole-intended-for-bone-treatment-and-regeneration
#6
Katarzyna Czarnobaj, Magdalena Prokopowicz, Wiesław Sawicki
The purpose of this study was to evaluate the surface mineralization activity and in vitro drug behavior potential of two forms of mesoporous silica: powder and granulate. Ordered mesoporous SiO2 powder was synthesized by surfactant-assisted sol-gel process using tetraethoxysilane as a silica precursor and hexadecyltrimethylammonium bromide as the structure-directing agent. The granulate was prepared using silica powder and ethyl cellulose as a binding agent. Metronidazole (MT)-an anti-inflammatory substance and doxorubicin hydrochloride (ChD)-an anti-cancer drug were chosen as drug models for delivery studies...
May 22, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28530835/on-the-formation-of-epitaxially-connected-quantum-dot-solids-nucleation-and-coherent-phase-transition
#7
Kevin Whitham, Tobias Hanrath
The formation of epitaxially connected quantum dot solids involves a complex interplay of interfacial assembly, surface chemistry, and irreversible directed attachment. We describe the basic mechanism in context of a coherent phase transition with distinct nucleation and propagation steps. The proposed mechanism explains how defects in the pre-assembled structure influence nucleation and how basic geometric relationships govern the transformation from hexagonal assemblies of isolated dots to interconnected solids with square symmetry...
May 22, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28530829/highly-oriented-atomically-thin-ambipolar-mose2-grown-by-molecular-beam-epitaxy
#8
Ming-Wei Chen, Dmitry Ovchinnikov, Sorin Lazar, Michele Pizzochero, Michael Brian Whitwick, Alessandro Surrente, Michal Baranowski, Oriol Lopez Sanchez, Philippe Gillet, Paulina Plochocka, Oleg V Yazyev, Andras Kis
Transition metal dichalcogenides (TMDCs), together with other two-dimensional (2D) materials have attracted great interest due to the unique optical and electrical properties of atomically thin layers. In order to fulfill their potential, developing large-area growth and understanding the properties of TMDCs have become crucial. Here, we used molecular beam epitaxy (MBE) to grow atomically thin MoSe2 on GaAs(111)B. No intermediate compounds were detected at the interface of as-grown films. Careful optimization of the growth temperature can result in the growth of highly aligned films with only two possible crystalline orientations due to broken inversion symmetry...
May 22, 2017: ACS Nano
https://www.readbyqxmd.com/read/28530750/first-principles-study-of-the-structural-stability-and-electrochemical-properties-of-na2msio4-m-mn-fe-co-and-ni-polymorphs
#9
F Bianchini, H Fjellvåg, P Vajeeston
Sodium orthosilicates Na2MSiO4 (M = Mn, Fe, Co and Ni) have attracted much attention due to the possibility of exchanging two electrons per formula unit. They are also found to exhibit great structural stability due to a diamond-like arrangement of tetrahedral groups. In this work, we have systematically studied the possible polymorphism of these compounds by means of density functional theory, optimising the structure of a number of systems with different group symmetries. The ground state is found to be Pc-symmetric for all the considered M = Mn, Fe, Co, Ni, and several similar structures exhibiting different symmetries coexist within a 0...
May 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28530633/enhanced-spin-orbit-coupling-in-tetragonally-strained-fe-co-b-films
#10
Ruslan Salikhov, Ludwig Reichel, Benjamin Zingsem, Radu Abrudan, Alexander Edström, Danny Thonig, Jan Rusz, Olle Eriksson, Ludwig Schultz, Sebastian Fahler, Michael Farle, Ulf Wiedwald
Tetragonally strained interstitial Fe-Co-B alloys were synthesized as epitaxial films grown on a 20 nm thick Au0.55Cu0.45 buffer layer. Different ratios of the perpendicular to in-plane lattice constant c/a = 1.013, 1.034 and 1.02 were stabilized by adding interstitial boron with different concentrations 0, 4, and 10 at.%, respectively. Using ferromagnetic resonance (FMR) and x-ray magnetic circular dichroism (XMCD) we found that the total orbital magnetic moment significantly increases with increasing c/a ratio, indicating that reduced crystal symmetry and interstitial B leads to a noticeable enhancement of the effect of spin-orbit coupling (SOC) in the Fe-Co-B alloys...
May 22, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28530498/negative-consequences-of-low-energy-availability-in-natural-male-bodybuilding-a-review
#11
Petter Fagerberg
Energy availability (EA) is a scientific concept describing how much energy is available for basic metabolic functions such as reproduction, immunity and skeletal homeostasis. Carefully controlled studies on women have shown pathological effects of EA<30kcal/kg fat free mass (FFM) and this state has been labeled low EA (LEA). Bodybuilding is a sport in which athletes compete to show muscular definition, symmetry and low body fat. The process of contest preparation in bodybuilding includes months of underfeeding, thus increasing the risk of LEA and its negative health consequences...
May 22, 2017: International Journal of Sport Nutrition and Exercise Metabolism
https://www.readbyqxmd.com/read/28530486/y-balance-test-performance-following-a-competitive-field-hockey-season-a-pretest-posttest-study
#12
Matthew C Hoch, Lauren A Welsch, Emily M Hartley, Cameron J Powden, Johanna M Hoch
CONTEXT: The Y-Balance Test (YBT) is a dynamic balance assessment used as a preseason musculoskeletal screen to determine injury risk. While the YBT has demonstrated excellent test-retest reliability, it is unknown if YBT performance changes following participation in a competitive athletic season. OBJECTIVE: Determine if a competitive athletic season affects YBT performance in field hockey players. DESIGN: Pretest-posttest. SETTING: Laboratory...
May 22, 2017: Journal of Sport Rehabilitation
https://www.readbyqxmd.com/read/28530233/artificial-control-of-the-bias-voltage-dependence-of-tunnelling-anisotropic-magnetoresistance-using-quantization-in-a-single-crystal-ferromagnet
#13
Iriya Muneta, Toshiki Kanaki, Shinobu Ohya, Masaaki Tanaka
A major issue in the development of spintronic memory devices is the reduction of the power consumption for the magnetization reversal. For this purpose, the artificial control of the magnetic anisotropy of ferromagnetic materials is of great importance. Here, we demonstrate the control of the carrier-energy dependence of the magnetic anisotropy of the density of states (DOS) using the quantum size effect in a single-crystal ferromagnetic material, GaMnAs. We show that the mainly twofold symmetry of the magnetic anisotropy of DOS, which is attributed to the impurity band, is changed to a fourfold symmetry by enhancing the quantum size effect in the valence band of the GaMnAs quantum wells...
May 22, 2017: Nature Communications
https://www.readbyqxmd.com/read/28529935/modified-fisher-method-for-unilateral-cleft-lip-report-of-cases
#14
Hui Young Kim, Joonhyoung Park, Ming-Chih Chang, In Seok Song, Byoung Moo Seo
BACKGROUND: Rehabilitation of normal function and form is essential in cleft lip repair. In 2005, Dr. David M. Fisher introduced an innovative method, named "an anatomical subunit approximation technique" in unilateral cleft lip repair. According to this method, circumferential incision along the columella on cleft side of the medial flap is continued to the planned top of the Cupid's bow in straight manner, which runs parallel to the unaffected philtral ridge. Usually, small inlet incision is needed to lengthen the medial flap...
December 2017: Maxillofacial Plastic and Reconstructive Surgery
https://www.readbyqxmd.com/read/28529804/unilateral-discomfort-increases-the-use-of-contralateral-side-during-sit-to-stand-transfer
#15
Simisola O Oludare, Charlie C Ma, Alexander S Aruin
Individuals with unilateral impairment perform symmetrical movements asymmetrically. Restoring symmetry of movements is an important goal of rehabilitation. The aim of the study was to evaluate the effect of using discomfort-inducing devices on movement symmetry. Fifteen healthy individuals performed the sit-to-stand (STS) maneuver using devices inducing unilateral discomfort under the left sole and left thigh or right sole and right thigh and without them. 3D body kinematics, ground reaction forces, electrical activity of muscles, and the level of perceived discomfort were recorded...
2017: Rehabilitation Research and Practice
https://www.readbyqxmd.com/read/28529794/crystal-structures-of-two-alkaline-earth-m-ba-and-sr-dimanganese-ii-iron-iii-tris-orthophosphates
#16
Ghaleb Alhakmi, Abderrazzak Assani, Mohamed Saadi, Lahcen El Ammari
Two new orthophosphates, BaMn2Fe(PO4)3 [barium dimanganese(II) iron(III) tris-(orthophosphate)] and SrMn2Fe(PO4)3 [strontium dimanganese(II) iron(III) tris-(orthophosphate)], were synthesized by solid-state reactions. They are isotypic and crystallize in the ortho-rhom-bic system with space group type Pbcn. Their crystal structures comprise infinite zigzag chains of edge-sharing FeO6 octa-hedra (point group symmetry .2.) and Mn2O10 double octa-hedra running parallel to [001], linked by two types of PO4 tetra-hedra...
May 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28529791/crystal-structure-of-1-4-8-11-tetra-azonia-cyclo-tetra-decane-bis-dichromate-monohydrate-from-synchrotron-data
#17
Dohyun Moon, Jong-Ha Choi
The asymmetric unit of the hydrated title salt, (C10H28N4)[Cr2O7]2·H2O [C10H28N4 = H4(cyclam) = 1,4,8,11-tetra-azonia-cyclo-tetra-deca-ne], contains two half-cations (both completed by crystallographic inversion symmetry), two dichromate anions and one water mol-ecule. The two [CrO7](2-) anions exhibit a nearly staggered conformation, with bridging angles of 133.37 (11) and 136.28 (12)°. The distortions of the dichromate anions are due to their participation in hydrogen-bonding inter-actions with the water mol-ecule and the cations...
May 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28529786/the-crystal-structures-of-three-pyrazine-2-5-dicarb-oxamides-three-dimensional-supra-molecular-structures
#18
Dilovan S Cati, Helen Stoeckli-Evans
The complete mol-ecules of the title compounds, N(2),N(5)-bis-(pyridin-2-ylmeth-yl)pyrazine-2,5-dicarboxamide, C18H16N6O2 (I), 3,6-dimethyl-N(2),N(5)-bis-(pyridin-2-yl-meth-yl)pyrazine-2,5-dicarboxamide, C20H20N6O2 (II), and N(2),N(5)-bis-(pyridin-4-ylmeth-yl)pyrazine-2,5-dicarboxamide, C18H16N6O2 (III), are generated by inversion symmetry, with the pyrazine rings being located about centres of inversion. Each mol-ecule has an extended conformation with the pyridine rings inclined to the pyrazine ring by 89...
May 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28529782/crystal-structure-of-the-mixed-metal-tris-ulfide-bacu1-3ta2-3s3
#19
Kejun Bu, Jianqiao He, Dong Wang, Chong Zheng, Fuqiang Huang
The mixed-metal title compound, BaCu1/3Ta2/3S3 [barium copper(II) tantalum(V) tris-ulfide], was prepared through solid-state reactions. The crystal structure adopts the BaTaS3 structure type and consists of face-sharing [MS6] (M = Ta,Cu) octa-hedra (point-group symmetry -3m.) that are condensed into infinite chains along [001]. Adjacent chains are linked through the barium cations (site symmetry -6m2), which exhibit a coordination number of twelve. The M site is occupied by 2/3 of Ta(V) and 1/3 of Cu(II), whereby the average M-S distances are slightly longer than those of ordered BaTaS3...
May 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28529771/c-i%C3%A2-n-short-contacts-as-tools-for-the-construction-of-the-crystal-packing-in-the-crystal-structure-of-3-3-ethane-1-2-di-yl-bis-6-iodo-3-4-di-hydro-2h-1-3-benzoxazine
#20
Augusto Rivera, Jicli José Rojas, Jaime Ríos-Motta, Michael Bolte
The asymmetric unit of the title compound, C18H18I2N2O2, consists of one half-mol-ecule, completed by the application of inversion symmetry. The mol-ecule adopts the typical structure for this class of bis-benxozazines, characterized by an anti orientation of the two benzoxazine rings around the central C-C bond. The oxazinic ring adopts a half-chair conformation. In the crystal, mol-ecules are linked by C-I⋯N short contacts [I⋯N = 3.378 (2) Å], generating layers lying parallel to the bc plane.
May 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
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