Tetra-n-propyl­ammonium chloride monohydrate

The crystal structure of the title salt hydrate, C12H28N+·Cl−·H2O, consists of non-inter­acting cations and anions. The water mol­ecule forms hydrogen bonds to two chloride ions, about a center of inversion, generating a planar eight-membered {⋯H—O—H⋯Cl}2 ring

Geometrical quadrupolar frustration in DyB4_4

Physical properties of DyB$_4$ have been studied by magnetization, specific heat, and ultrasonic measurements. The magnetic entropy change and the ultrasonic properties in the intermediate phase II indicate that the degeneracy of internal degrees of freedom is not fully lifted in spite of the formation of magnetic order. The ultrasonic attenuation and the huge softening of $C_{44}$ in phase II suggests existence of electric-quadrupolar (orbital) fluctuations of the 4$f$-electron. These unusual properties originate from the geometrical quadrupolar frustration.Comment: 4 pages, 4 figures, accepted for publication in Journal of the Physical Society of Japa

Virtual blasting system for removal of coating and/or rust from a virtual surface

A computer simulation and virtual reality system simulates the use of a blasting nozzle to remove one or more coatings and/or rust from a virtual surface. The user operates an electronic controller in the form of a blasting nozzle that outputs a signal indicating whether the blasting nozzle controller is in an on position or in an off position. The system also has a motion tracking system that tracks the position and orientation of the blasting nozzle controller with respect to the virtual surface defined on the display screen. Simulation software in a computer generates virtual blast pattern data, and the removal of the virtual coating(s) and/or rust image from the virtual surface is displayed in real time on the display screen

Increased glutamine in leaves of poplar transgenic with pine GS1a caused greater anthranilate synthetase α-subunit (ASA1) transcript and protein abundances: an auxin-related mechanism for enhanced growth in GS transgenics?

The initial reaction in the pathway leading to the production of indole-3-acetic acid (IAA) in plants is the reaction between chorismate and glutamine to produce anthranilate, catalysed by the enzyme anthranilate synthase (ASA; EC 4.1.3.27). Compared with non-transgenic controls, leaves of transgenic poplar with ectopic expression of the pine cytosolic glutamine synthetase (GS1a; EC 6.3.1.2) produced significantly greater glutamine and significantly enhanced ASA α-subunit (ASA1) transcript and protein (approximately 130% and 120% higher than in the untransformed controls, respectively). Similarly, tobacco leaves fed with 30 mM glutamine and 2 mM chorismate showed enhanced ASA1 transcript and protein (175% and 90% higher than controls, respectively). Furthermore, free IAA was significantly elevated both in leaves of GS1a transgenic poplar and in tobacco leaves fed with 30 mM glutamine and 2 mM chorismate. These results indicated that enhanced cellular glutamine may account for the enhanced growth in GS transgenic poplars through the regulation of auxin biosynthesis

Quasi-hydrostatic X-ray powder diffraction study of the low- and high-pressure phases of CaWO4 up to 28 GPa

We have studied CaWO4 under compression using Ne as pressure-transmitting medium at room temperature by means of synchrotron X-ray powder diffraction. We have found that CaWO4 beyond 8.8 GPa transforms from its low-pressure tetragonal structure (scheelite) into a monoclinic structure (fergusonite). The high-pressure phase remains stable up to 28 GPa and the low-pressure phase is totally recovered after full decompression. The pressure dependence of the unit-cell parameters, as well as the pressure volume equation of state, has been determined for both phases. Compared with previous studies, we found in our quasi-hydrostatic experiments a different behavior for the unit-cell parameters of the fergusonite phase and a different transition pressure. These facts suggest that deviatoric stresses influence on the high-pressure structural behavior of CaWO4 as previously found in related compounds. The reported experiments also provide information on the pressure dependence of interatomic bond distances, shedding light on the transition mechanisms. (C) 2014 Elsevier Masson SAS. All rights reserved.Research sponsored by Spanish MINECO (MAT2010-21270-C04-01/04 and CSD2007-00045). Portions of this work were performed at HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory. HPCAT operations are supported by DOE-NNSA under Award No. DE-NA0001974 and DOE-BES under Award No. DE-FG02-99ER45775, with partial instrumentation funding by NSF. APS is supported by DOE-BES, under Contract No. DE-AC02-06CH11357.Vilaplana Cerda, RI.; Lacomba-Perales, R.; Gomis, O.; Errandonea, D.; Meng, Y. (2014). Quasi-hydrostatic X-ray powder diffraction study of the low- and high-pressure phases of CaWO4 up to 28 GPa. Solid State Sciences. 36:16-23. https://doi.org/10.1016/j.solidstatesciences.2014.07.003S16233

Defining the structural requirements for ribose 5-phosphate-binding and intersubunit cross-talk of the malarial pyridoxal 5-phosphate synthase

Most organisms synthesise the B(6) vitamer pyridoxal 5-phosphate (PLP) via the glutamine amidotransferase PLP synthase, a large enzyme complex of 12 Pdx1 synthase subunits with up to 12 Pdx2 glutaminase subunits attached. Deletion analysis revealed that the C-terminus has four distinct functionalities: assembly of the Pdx1 monomers, binding of the pentose substrate (ribose 5-phosphate), formation of the reaction intermediate I(320), and finally PLP synthesis. Deletions of distinct C-terminal regions distinguish between these individual functions. PLP formation is the only function that is conferred to the enzyme by the C-terminus acting in trans, explaining the cooperative nature of the complex