Redirected Walking in Infinite Virtual Indoor Environment Using Change-blindness

We present a change-blindness based redirected walking algorithm that allows a user to explore on foot a virtual indoor environment consisting of an infinite number of rooms while at the same time ensuring collision-free walking for the user in real space. This method uses change blindness to scale and translate the room without the user's awareness by moving the wall while the user is not looking. Consequently, the virtual room containing the current user always exists in the valid real space. We measured the detection threshold for whether the user recognizes the movement of the wall outside the field of view. Then, we used the measured detection threshold to determine the amount of changing the dimension of the room by moving that wall. We conducted a live-user experiment to navigate the same virtual environment using the proposed method and other existing methods. As a result, users reported higher usability, presence, and immersion when using the proposed method while showing reduced motion sickness compared to other methods. Hence, our approach can be used to implement applications to allow users to explore an infinitely large virtual indoor environment such as virtual museum and virtual model house while simultaneously walking in a small real space, giving users a more realistic experience.Comment: https://www.youtube.com/watch?v=s-ZKavhXxd

Spin-Orbit Coupling in Iridium-Based 5d Compounds Probed by X-ray Absorption Spectroscopy

We have performed x-ray absorption spectroscopy (XAS) measurements on a series of Ir-based 5d transition metal compounds, including Ir, IrCl3, IrO2, Na2IrO3, Sr2IrO4, and Y2Ir2O7. By comparing the intensity of the "white-line" features observed at the Ir L2 and L3 absorption edges, it is possible to extract valuable information about the strength of the spin-orbit coupling in these systems. We observe remarkably large, non-statistical branching ratios in all Ir compounds studied, with little or no dependence on chemical composition, crystal structure, or electronic state. This result confirms the presence of strong spin-orbit coupling effects in novel iridates such as Sr2IrO4, Na2IrO3, and Y2Ir2O7, and suggests that even simple Ir-based compounds such as IrO2 and IrCl3 may warrant further study. In contrast, XAS measurements on Re-based 5d compounds, such as Re, ReO2, ReO3, and Ba2FeReO6, reveal statistical branching ratios and negligible spin-orbit coupling effects.Comment: 9 pages, 4 figure

Substitution of Heavy Complementarity Determining Region 3 (CDR-H3) Residues Can Synergistically Enhance Functional Activity of Antibody and Its Binding Affinity to HER2 Antigen

To generate a biobetter that has improved therapeutic activity, we constructed scFv libraries via random mutagenesis of several residues of CDR-H3 and -L3 of hu4D5. The scFv clones were isolated from the phage display libraries by stringent panning, and their anti-proliferative activity against HER2-positive cancer cells was evaluated as a primary selection criterion. Consequently, we selected AH06 as a biobetter antibody that had a 7.2-fold increase in anti-proliferative activity (IC50: 0.81 nM) against the gastric cancer cell line NCI-N87 and a 7.4-fold increase in binding affinity (K-D : 60 pM) to HER2 compared to hu4D5. The binding energy calculation and molecular modeling suggest that the substitution of residues of CDR-H3 to W98, F100c, A101 and L102 could stabilize binding of the antibody to HER2 and there could be direct hydrophobic interactions between the aromatic ring of W98 and the aliphatic group of I613 within HER2 domain IV as well as the heavy and light chain hydrophobic interactions by residues F100c, A101 and L102 of CDR-H3. Therefore, we speculate that two such interactions were exerted by the residues W98 and F100c. A101 and L102 may have a synergistic effect on the increase in the binding affinity to HER2. AH06 specifically binds to domain IV of HER2, and it decreased the phosphorylation level of HER2 and AKT. Above all, it highly increased the overall level of p27 compared to hu4D5 in the gastric cancer cell line NCI-N82, suggesting that AH06 could potentially be a more efficient therapeutic agent than hu4D5.OAIID:RECH_ACHV_DSTSH_NO:T201620640RECH_ACHV_FG:RR00200001ADJUST_YN:EMP_ID:A002901CITE_RATE:2.67DEPT_NM:화학생물공학부EMAIL:[email protected]_YN:YCONFIRM:

Determination of Hund's coupling in 5d oxides using resonant inelastic x-ray scattering

We report resonant inelastic x-ray scattering (RIXS) measurements on ordered double-perovskite samples containing Re5+ and Ir5+ with 5d2 and 5d4 electronic configurations, respectively. In particular, the observed RIXS spectra of Ba2YReO6 and Sr2MIrO6 (M = Y, Gd) show sharp intra-t2g transitions, which can be quantitatively understood using a minimal atomic Hamiltonian incorporating spin-orbit coupling λ and Hund's coupling JH. Our analysis yields λ=0.38(2)eV with JH=0.26(2)eV for Re5+ and λ=0.42(2)eV with JH=0.25(4)eV for Ir5+. Our results provide sharp estimates for Hund's coupling in 5d oxides and suggest that it should be treated on equal footing with spin-orbit interaction in multiorbital 5d transition-metal compounds. © 2017 American Physical Society19101sciescopu

Plasma transforming growth factor β1 as a biochemical marker to predict the persistence of atrial fibrillation after the surgical maze procedure

ObjectivesThe Cox maze procedure was developed as a surgical treatment for atrial fibrillation. However, atrial fibrillation recurs in some patients, and atrial remodeling in the form of fibrosis can lead to perpetuation of atrial fibrillation. To identify the predictor of the persistence of atrial fibrillation after the maze procedure using cryoablation, we evaluated the preoperative plasma transforming growth factor β1. We also examined the correlations between plasma transforming growth factor β1 levels and the degree of atrial fibrosis.MethodsPreoperative plasma transforming growth factor β1 levels were measured in 86 consecutive patients (age, 54 ± 12 years) who underwent both the open heart operation for valvular heart disease and the surgical maze procedure with cryoablation for persistent atrial fibrillation. We measured the degree of fibrosis from the tissue of the left atrium.ResultsAt 1 year's follow-up, 10 of 86 patients had persistent atrial fibrillation. Patients with persistent atrial fibrillation had higher preoperative plasma transforming growth factor β1 levels than the patients with sinus rhythm (0.44 ± 0.29 vs 0.32 ± 0.15 ng/mL, P = .03). Patients with persistent atrial fibrillation had higher mRNA expressions of collagen III and lower mRNA expressions of atrial natriuretic peptide than those with sinus rhythm, and the plasma transforming growth factor β1 levels correlated with the degree of fibrosis in the left atrium (r = 0.497, P = .022). Multiple logistic regression analysis revealed that plasma transforming growth factor β1 levels were independently associated with the postoperative persistence of atrial fibrillation at 1 year's follow-up.ConclusionsPreoperative plasma transforming growth factor β1 levels could be used to predict the persistence of atrial fibrillation at 1 year's follow-up after the surgical maze procedure by using cryoablation. Preoperative plasma transforming growth factor β1 levels were correlated with the degree of fibrosis in the left atria of patients with mitral valvular heart disease