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1.
KL Britton HF Rogers Y Asano T Dairi Y Kato TJ Stillman DW Rice 《Acta crystallographica. Section D, Biological crystallography》1998,53(4):124-126
The novel NAD+-linked opine dehydrogenase from a soil isolate Arthrobacter sp. strain 1C belongs to an enzyme superfamily whose members exhibit quite diverse substrate specificites. Crystals of this opine dehydrogenase, obtained in the presence or absence of co-factor and substrates, have been shown to diffract to beyond 1.8 ? resolution. X-ray precession photographs have established that the crystals belong to space group P21212, with cell parameters a = 104.9, b = 80.0, c = 45.5 ? and a single subunit in the asymmetric unit. The elucidation of the three-dimensional structure of this enzyme will provide a structural framework for this novel class of dehydrogenases to enable a comparison to be made with other enzyme families and also as the basis for mutagenesis experiments directed towards the production of natural and synthetic opine-type compounds containing two chiral centres. 相似文献
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Maxwell Thomas Dylla Stephen Dongmin Kang G. Jeffrey Snyder 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(17):5557-5566
Perovskite oxides are candidate materials in catalysis, fuel cells, thermoelectrics, and electronics, where electronic transport is vital to their use. While the fundamental transport properties of these materials have been heavily studied, there are still key features that are not well understood, including the temperature‐squared behavior of their resistivities. Standard transport models fail to account for this atypical property because Fermi surfaces of many perovskite oxides are low‐dimensional and distinct from traditional semiconductors. In this work, the low‐dimensional Fermi surfaces of perovskite oxides are chemically interpreted in terms of two‐dimensional crystal orbitals that form the conduction bands. Using SrTiO3 as a case study, the d/p‐hybridization that creates these low‐dimensional electronic structures is reviewed and connected to its fundamentally different electronic properties. A low‐dimensional band model explains several experimental transport properties, including the temperature and carrier‐density dependence of the effective mass, the carrier‐density dependence of scattering, and the temperature dependence of resistivity. This work highlights how chemical bonding influences semiconductor transport. 相似文献
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Strachan JD Bitter M Ramsey AT Zarnstorff MC Arunasalam V Bell MG Bretz NL Budny R Bush CE Davis SL Dylla HF Efthimion PC Fonck RJ Fredrickson E Furth HP Goldston RJ Grisham LR Grek B Hawryluk RJ Heidbrink WW Hendel HW Hill KW Hsuan H Jaehnig KP Jassby DL Jobes F Johnson DW Johnson LC Kaita R Kampershroer J Knize RJ Kozub T LeBlanc B Levinton F La Marche PH Manos DM Mansfield DK McGuire K McNeill DH Meade DM Medley SS Morris W Mueller D Nieschmidt EB Owens DK Park H Schivell J Schilling G 《Physical review letters》1987,58(10):1004-1007
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A novel nanosheet carbon-TiO(2) support is used as a highly reactive substrate for the facile formation of well-dispersed 3-5 nm Pt and PdPt nanoparticles. The synthetic strategy does not require the use of ligands, strong reducing agent or heat. 相似文献
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S. V. Benson G. Biallas C. L. Bohn D. Douglas H. F. Dylla R. Evans 《Synchrotron Radiation News》2013,26(4):13-17
The relationship between the Brazilian Synchrotron Light Laboratory (LNLS) and the Brazilian industry started at the very early stages of the laboratory in the mid-1980s when the project proposal was submitted to the Brazilian government. Factors such as the relatively small size of the project, and the uniqueness and level of complexity of the technological challenges raised by the LNLS developers kept the Brazilian industry involved within a few areas. As a result, LNLS was led during the 1990s to dedicate in-house resources to internally develop more components and systems than initially expected and the LNLS staff established expertise in several critical areas for the success of the synchrotron facility construction and operation. Therefore what seemed initially to be a difficulty ended up being the driving force for fruitful industrial development projects bringing together LNLS and Brazilian companies. 相似文献
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Nikky Kortbeek Aleida Braaksma Ferry HF Smeenk Piet JM Bakker Richard J Boucherie 《The Journal of the Operational Research Society》2015,66(7):1061-1076
The design and operations of inpatient care facilities are typically largely historically shaped. A better match with the changing environment is often possible, and even inevitable due to the pressure on hospital budgets. Effectively organizing inpatient care requires simultaneous consideration of several interrelated planning issues. Also, coordination with upstream departments like the operating theatre and the emergency department is much-needed. We present a generic analytical approach to predict bed census on nursing wards by hour, as a function of the Master Surgical Schedule and arrival patterns of emergency patients. Along these predictions, insight is gained on the impact of strategic (ie, case mix, care unit size, care unit partitioning), tactical (ie, allocation of operating room time, misplacement rules), and operational decisions (ie, time of admission/discharge). The method is used in the Academic Medical Center Amsterdam as a decision-support tool in a complete redesign of the inpatient care operations. 相似文献
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Neil GR Bohn CL Benson SV Biallas G Douglas D Dylla HF Evans R Fugitt J Grippo A Gubeli J Hill R Jordan K Li R Merminga L Piot P Preble J Shinn M Siggins T Walker R Yunn B 《Physical review letters》2000,84(4):662-665
Jefferson Laboratory's kW-level infrared free-electron laser utilizes a superconducting accelerator that recovers about 75% of the electron-beam power. In achieving first lasing, the accelerator operated "straight ahead" to deliver 38-MeV, 1.1-mA cw current for lasing near 5 &mgr;m. The waste beam was sent directly to a dump while producing stable operation at up to 311 W. Utilizing the recirculation loop to send the electron beam back to the linac for energy recovery, the machine has now recovered cw average currents up to 5 mA, and has lased cw with up to 1720 W output at 3.1 &mgr;m. 相似文献
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Dylla AG Lee JA Stevenson KJ 《Langmuir : the ACS journal of surfaces and colloids》2012,28(5):2897-2903
Here, we present the Li(+) insertion behavior of mesoporous ordered TiO(2)(B) nanoparticles (meso-TiO(2)(B)). Using presynthesized 4 nm TiO(2)(B) nanoparticles as building blocks and a commercially available ethylene glycol-propylene glycol block copolymer (P123) as a structure-directing agent, we were able to produce mesoporous structures of high-purity TiO(2)(B) with nanocrystallinity and mesopore channels ranging from 10 to 20 nm in diameter. We compared the Li(+) insertion properties of nontemplated TiO(2)(B) nanoparticles (nano-TiO(2)(B)) to meso-TiO(2)(B) via voltammetry and galvanostatic cycling and found significant increases in overall Li(+) insertion capacity for the latter. While nano-TiO(2)(B) and meso-TiO(2)(B) both show surface charging (pseudocapacitive) Li(+) insertion behavior, meso-TiO(2)(B) exhibits a higher overall capacity especially at high charge rates. We attribute this effect to higher electrode/electrolyte contact area as well as the improved electron and ion transport in meso-TiO(2)(B). In this study, we have demonstrated the influence of both nanostructuring and mesoporosity on Li(+) insertion behavior by rationally controlling the overall architecture of the TiO(2)(B) materials. 相似文献