The Experts below are selected from a list of 5088 Experts worldwide ranked by ideXlab platform
Yasutoshi Okuno - One of the best experts on this subject based on the ideXlab platform.
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ab initio simulations of higher Miller Index si sio2 interfaces for fin field effect transistor and nanowire transistors
Journal of Applied Physics, 2016Co-Authors: Yuzheng Guo, J Robertson, Yasutoshi OkunoAbstract:Models of three representative higher Miller Index interfaces, Si(310):SiO2, Si(410):SiO2, and Si(331):SiO2, have been built by an ab-initio molecular dynamics method. We show that each interface can be made as a fully bonded network without any defects and has a reasonable electronic structure for use in fin field effect transistors or gate-all-around nanowire devices. The differences in numbers of oxygen bridges are attributed to the intermediate sub-oxide components and the atomic step structure. The interface bonding schemes to passivate different densities of dangling bonds on different facets are also analyzed.
Junsuk Rho - One of the best experts on this subject based on the ideXlab platform.
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amino acid and peptide directed synthesis of chiral plasmonic gold nanoparticles
Nature, 2018Co-Authors: Hyeeun Lee, Hyoyong Ahn, Jungho Mun, Yoon Young Lee, Minkyung Kim, Nam Heon Cho, Kiseok Chang, Wook Sung Kim, Junsuk RhoAbstract:Understanding chirality, or handedness, in molecules is important because of the enantioselectivity that is observed in many biochemical reactions 1 , and because of the recent development of chiral metamaterials with exceptional light-manipulating capabilities, such as polarization control2-4, a negative refractive Index 5 and chiral sensing 6 . Chiral nanostructures have been produced using nanofabrication techniques such as lithography 7 and molecular self-assembly8-11, but large-scale and simple fabrication methods for three-dimensional chiral structures remain a challenge. In this regard, chirality transfer represents a simpler and more efficient method for controlling chiral morphology12-18. Although a few studies18,19 have described the transfer of molecular chirality into micrometre-sized helical ceramic crystals, this technique has yet to be implemented for metal nanoparticles with sizes of hundreds of nanometres. Here we develop a strategy for synthesizing chiral gold nanoparticles that involves using amino acids and peptides to control the optical activity, handedness and chiral plasmonic resonance of the nanoparticles. The key requirement for achieving such chiral structures is the formation of high-Miller-Index surfaces ({hkl}, h ≠ k ≠ l ≠ 0) that are intrinsically chiral, owing to the presence of 'kink' sites20-22 in the nanoparticles during growth. The presence of chiral components at the inorganic surface of the nanoparticles and in the amino acids and peptides results in enantioselective interactions at the interface between these elements; these interactions lead to asymmetric evolution of the nanoparticles and the formation of helicoid morphologies that consist of highly twisted chiral elements. The gold nanoparticles that we grow display strong chiral plasmonic optical activity (a dis-symmetry factor of 0.2), even when dispersed randomly in solution; this observation is supported by theoretical calculations and direct visualizations of macroscopic colour transformations. We anticipate that our strategy will aid in the rational design and fabrication of three-dimensional chiral nanostructures for use in plasmonic metamaterial applications.
Wook Sung Kim - One of the best experts on this subject based on the ideXlab platform.
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amino acid and peptide directed synthesis of chiral plasmonic gold nanoparticles
Nature, 2018Co-Authors: Hyeeun Lee, Hyoyong Ahn, Jungho Mun, Yoon Young Lee, Minkyung Kim, Nam Heon Cho, Kiseok Chang, Wook Sung Kim, Junsuk RhoAbstract:Understanding chirality, or handedness, in molecules is important because of the enantioselectivity that is observed in many biochemical reactions 1 , and because of the recent development of chiral metamaterials with exceptional light-manipulating capabilities, such as polarization control2-4, a negative refractive Index 5 and chiral sensing 6 . Chiral nanostructures have been produced using nanofabrication techniques such as lithography 7 and molecular self-assembly8-11, but large-scale and simple fabrication methods for three-dimensional chiral structures remain a challenge. In this regard, chirality transfer represents a simpler and more efficient method for controlling chiral morphology12-18. Although a few studies18,19 have described the transfer of molecular chirality into micrometre-sized helical ceramic crystals, this technique has yet to be implemented for metal nanoparticles with sizes of hundreds of nanometres. Here we develop a strategy for synthesizing chiral gold nanoparticles that involves using amino acids and peptides to control the optical activity, handedness and chiral plasmonic resonance of the nanoparticles. The key requirement for achieving such chiral structures is the formation of high-Miller-Index surfaces ({hkl}, h ≠ k ≠ l ≠ 0) that are intrinsically chiral, owing to the presence of 'kink' sites20-22 in the nanoparticles during growth. The presence of chiral components at the inorganic surface of the nanoparticles and in the amino acids and peptides results in enantioselective interactions at the interface between these elements; these interactions lead to asymmetric evolution of the nanoparticles and the formation of helicoid morphologies that consist of highly twisted chiral elements. The gold nanoparticles that we grow display strong chiral plasmonic optical activity (a dis-symmetry factor of 0.2), even when dispersed randomly in solution; this observation is supported by theoretical calculations and direct visualizations of macroscopic colour transformations. We anticipate that our strategy will aid in the rational design and fabrication of three-dimensional chiral nanostructures for use in plasmonic metamaterial applications.
Alan H Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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rheolytic thrombectomy with or without adjunctive indwelling pharmacolysis in patients presenting with acute pulmonary embolism presenting with right heart strain and or pulseless electrical activity
Thrombosis, 2011Co-Authors: J Hubbard, Wael A Saad, S S Sabri, Ulku C Turba, John F Angle, Auh Whan Park, Alan H MatsumotoAbstract:Purpose. To evaluate the safety and efficacy of the Possis rheolytic thrombectomy with or without indwelling catheter-directed pharmacolysis for the treatment of massive pulmonary embolus in patients presenting with right heart strain and/or a pulseless electrical activity (PEA). Materials and Methods. Retrospective review of patients undergoing pulmonary pharmacolysis was performed (07/2004–06/2009). Pre- and posttreatment Miller Index scoring weres calculated and compared. Patients were evaluated for tPA doses, ICU stay, hospital stay, and survival by Kaplan-Meier analysis. Results. 11 patients with massive PE were found, with 10/11 presenting with a Miller score of >17 (range: 16–27, mean: 23.2). CTPA and/or echocardiographic evidence of right heart strain was found in 10/11 patients. 3 (27%) patients presented with a PEA event. Two (18%) patients had a contraindication to pharmacolysis and were treated with mechanical thrombectomy alone. The intraprocedural mortality was 9% (
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doi:10.1155/2011/246410 Clinical Study Rheolytic Thrombectomy with or without Adjunctive Indwelling Pharmacolysis in Patients Presenting with Acute Pulmonary Embolism Presenting with Right
2011Co-Authors: Heart Strain, Auh Whan Park, Or Pulseless Electrical Activity, Alan H MatsumotoAbstract:Copyright © 2011 J. Hubbard et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Purpose. Toevaluatethesafetyandefficacy of the Possis rheolytic thrombectomy with or without indwelling catheter-directed pharmacolysis for the treatment of massive pulmonary embolus in patients presenting with right heart strain and/or a pulseless electrical activity (PEA). Materials and Methods. Retrospective review of patients undergoing pulmonary pharmacolysis was performed (07/2004–06/2009). Pre- and posttreatment Miller Index scoring weres calculated and compared. Patients were evaluated for tPA doses, ICU stay, hospital stay, and survival by Kaplan-Meier analysis. Results. 11 patients with massive PE were found, with 10/11 presenting with a Miller score of>17 (range: 16–27, mean: 23.2). CTPA and/or echocardiographic evidence of right heart strain was found in 10/11 patients. 3 (27%) patients presented with a PEA event. Two (18%) patients had a contraindication to pharmacolysis and were treated with mechanical thrombectomy alone. The intraprocedural mortality was 9 % (n = 1/11). Of the 10 patients who survived the initial treatment, 7 patients underwent standard mechanical thrombectomy initially, while 5 received power pulse spray mechanical thrombectomy. Eight of these 10 patients underwent adjunctive indwelling catheter-directed thrombolysis. The mean catheter-directed infusion duration was 18 hours (range of 12–26 hours). The averag
Andre Stesmans - One of the best experts on this subject based on the ideXlab platform.
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inherent point defects at the thermal higher Miller Index 211 si sio2 interface
Applied Physics Letters, 2014Co-Authors: Serena Iacovo, Andre StesmansAbstract:Electron spin resonance (ESR) studies were carried out on the higher-Miller Index (211)Si/SiO2 interface thermally grown in the temperature range Tox = 400–1066 °C to assess interface quality in terms of inherently incorporated point defects. This reveals the presence predominantly of two species of a Pb-type interface defect (interfacial Si dangling bond), which, based on pertinent ESR parameters, is typified as Pb0(211) variant, close to the Pb0 center observed in standard (100)Si/SiO2—known as utmost detrimental interface trap. Tox ≳ 750 °C is required to minimize the Pb0(211) defect density (∼4.2 × 1012 cm−2; optimized interface). The data clearly reflect the non-elemental nature of the (211)Si face as an average of (100) and (111) surfaces. It is found that in oxidizing (211)Si at Tox ≳ 750 °C, the optimum Si/SiO2 interface quality is retained for the two constituent low-Index (100) and (111) faces separately, indicating firm anticipating power for higher-Index Si/SiO2 interfaces in general. It impli...