35.4 T field generated using a layer-wound superconducting coil made of (RE)Ba2Cu3O7-x (RE = Rare Earth) coated conductor

To explore the limits of layer wound (RE)Ba2Cu3O7-x (REBCO, RE = Rare Earth) coils in a high magnetic field environment > 30 T, a series of small insert coils have been built and characterized in background fields. One of the coils repeatedly reached 35.4 T using a single ~100 m length of REBCO tape wet wound with epoxy and nested in a 31 T background magnet. The coil was quenched safely several times without degradation. Contributing to the success of this coil was the introduction of a thin polyester film that surrounded the conductor. This approach introduces a weak circumferential plane in the coil pack that prevents conductor delamination that has caused degradation of several epoxy impregnated coils previously made by this and other groups.Comment: 7 pages, 3 figures, 1 tabl

Synthesis of Core-Modified Third-Generation Light-Driven Molecular Motors

The synthesis and characterization of a series of light-driven third-generation molecular motors featuring various structural modifications at the central aromatic core are presented. We explore a number of substitution patterns, such as 1,2-dimethoxybenzene, naphthyl, 1,2-dichlorobenzene, 1,1 ':2',1 ''-terphenyl, 4,4 ''-dimethoxy-1,1':2',1 ''-terphenyl, and 1,2-dicarbome-thoxybenzene, considered essential for designing future responsive systems. In many cases, the synthetic routes for both synthetic intermediates and motors reported here are modular, allowing for their post-functionalization. The structural modifications introduced in the core of the motors result in improved solubility and a bathochromic shift of the absorption maxima. These features, in combination with a structural design that presents remote functionalization of the stator with respect to the fluorene rotors, make these novel motors particularly promising as light-responsive actuators in covalent and supramolecular materials

Tetra­guanidinium bis­[citrato(3−)]cuprate(II) dihydrate

The asymmetric unit of the title compound, (CH6N3)4[Cu(C6H5O7)2]·2H2O, contains one-half of a centrosymmetric CuII complex anion, two guanidinium cations and a water mol­ecule. The CuII ion, lying on a crystallographic inversion center, is hexa­coordinated with two citrate anions in a distorted octahedral geometry. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal structure, mol­ecules are linked into a three-dimensional framework by inter­molecular N—H⋯O and O—H⋯O hydrogen bonds

ODAM Expression Inhibits Human Breast Cancer Tumorigenesis

We have posited that Odontogenic Ameloblast Associated Protein (ODAM) serves as a novel prognostic biomarker in breast cancer and now have investigated its potential role in regulating tumor growth and metastasis. Human breast cancer MDA-MB-231 cells were transfected with a recombinant ODAM plasmid construct (or, as a control, the plasmid vector alone). ODAM expression increased adhesion and apoptosis of the transfected MDA-MB-231 cells and suppressed their growth rate, migratory activity, and capability to invade extracellular matrix-coated membranes. Implantation of such cells into mouse mammary fat pads resulted in significantly smaller tumors than occurred in animals that received control cells; furthermore, ODAM-expressing cells, when injected intravenously into mice, failed to metastasize, whereas the control-transfected counterparts produced extensive lung lesions. Our finding that induction of ODAM expression in human breast cancer cells markedly inhibited their neoplastic properties provides further evidence for the regulatory role of this molecule in tumorigenesis and, consequently, is of potential clinical import

Experimental evidence for an intermediate phase in the multiferroic YMnO3

We have studied YMnO$_{3}$ by high-temperature synchrotron X-ray powder diffraction, and have carried out differential thermal analysis and dilatometry on a single crystal sample. These experiments show two phase transitions at about 1100K and 1350K, respectively. This demonstrates the existence of an intermediate phase between the room temperature ferroelectric and the high temperature centrosymmetric phase. This study identifies for the first time the different high-temperature phase transitions in YMnO$_{3}$.Comment: 10 pages 5 figures. New version, Additional data, Journal of Physics: Condensed Matter, in Pres

Bunch Length Measurements at the CEBAF Injector at 130 kV

In this work, we investigated the evolution in bunch length of beams through the CEBAF injector for low to high charge per bunch. Using the General Particle Tracer (GPT), we have simulated the beams through the beamline of the CEBAF injector and analyzed the beam to get the bunch lengths at the location of chopper. We performed these simulations with the existing injector using a 130 kV gun voltage. Finally, we describe measurements to validate these simulations. The measurements have been done using chopper scanning technique for two injector laser drive frequency modes: one with 500 MHz, and another with 250 MHz

New Results at JLab Describing Operating Lifetime of GaAs Photo-Guns

Polarized electrons from GaAs photocathodes have been key to some of the highest-impact results of the Jefferson Lab science program over the past 30 years. During this time, various studies have given insight into improving the operational lifetime of these photocathodes in DC high-voltage photo-guns while using lasers with spatial Gaussian profiles of typically 0.5 mm to 1 mm FWHM, cathode voltages of 100 kV to 130 kV, and a wide range of beam currents up to multiple mA. In this contribution, we show recent experimental data from a 100 kV to 180 kV setup and describe our progress at predicting the lifetime based on the calculable dynamics of ionized gas molecules inside the gun. These new experimental studies at Jefferson Lab are specifically aimed at exploring the ion damage of higher-voltage guns being built for injectors

Crystal Structure of 2′,3′-Di-O-Acetyl-5′-Deoxy-5-Fluorocytidine with N–H···(O,F) Proton Donor Bifurcated and (C,N)–H···O Bifurcated Acceptor Dual Three-Center Hydrogen Bond Configurations

The title compound, C13H16O6N3F, features a central furan ring containing four carbon atom chiral centers with a 4-amino-5-fluoro-2-oxopyrimidine group, two acetyl groups and a methyl group bonded at the 2,3,4,5 positions, each in an absolute R configuration (2R,3R,4R,5R). It crystallizes in the monoclinic space group C2 with unit cell parameters a = 14.5341(3), b = 7.26230(10), c = 16.2197(3) Å, β = 116.607(2)°, Z = 4. An extensive array of intra and inter molecular hydrogen bond interactions dominate crystal packing in the unit cell highlighted by a relatively rare three-center proton-bifurcated donor N–H···(O,F) hydrogen bond interaction in cooperation with a second, (C,N)–H···O bifurcated acceptor three-center hydrogen bond in a supportive fashion. Additional weak Cg π-ring inter molecular interactions between a fluorine atom and the 4-amino-5-fluoro-2-oxopyrimidine ring in concert with multiple donor and acceptor hydrogen bonds significantly influence the bond distances, bond angles and torsion angles of the deoxy-5-fluorocytidine group. Comparison to a MOPAC computational calculation provides support to these observations

Complexes of Iron(II) with silylated pentalene ligands; building blocks for homo- and heterobimetallics

A range of iron(II) complexes incorporating the silylated pentalene ligands (Pn†H = 1,4-{SiiPr3}2C8H5 and Pn† = 1,4-{SiiPr3}2C8H4) have been investigated as model molecules/building blocks for metallocene-based polymers. Six complexes have been synthesised and extensively characterised by a range of techniques, including by cyclic voltammetry and X-ray diffraction studies. Amongst these compounds are the homobimetallic [Cp∗Fe]2(μ-Pn†) which is a fused analogue of biferrocene, and the 3d/4s heterobimetallic [Cp∗Fe(η5-Pn†)][K] which forms an organometallic polymer in the solid state. DFT calculations on model mono-Fe(η5-Pn) compounds reveal the charge densities on the uncoordinated carbon atoms of the pentalene ligand, and hence the potential for incorporating these units into heteronuclear bimetallic complexes is assessed

Structures of (5′S)-8,5′-Cyclo-2′-deoxyguanosine Mismatched with dA or dT

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