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We have carried out Raman spectroscopy experiments to investigate two-magnon excitations in epitaxial thin films of the quasi-two-dimensional antiferromagnetic Mott insulator Sr$_2$IrO$_4$ under in-plane misfit strain. With in-plane biaxial compression, the energy of the two-magnon peak increases, and the peak remains observable over a wider temperature range above the N\'eel temperature, indicating strain-induced enhancement of the superexchange interactions between $\it{J}_{eff}$ = 1/2 pseudospins. From density functional theory calculations, we have found an increase of the nearest-neighbor hopping parameter and exchange interaction with increasing biaxial compressive strain, in agreement with the experimental observations. Our experimental and theoretical results provide perspectives for systematic, theory-guided strain control of the primary exchange interactions in 5$\it{d}$ transition metal oxides., Comment: 3 figures

We have investigated structural, transport, and optical properties of tensile strained (Sr$_{1-x}$La$_x$)$_3$Ir$_2$O$_7$ (x = 0, 0.025, 0.05) epitaxial thin-films. While High-T$_c$ superconductivity is predicted theoretically in the system, we have observed that all of the samples remain insulating with finite optical gap energies and Mott variable-range hopping characteristics in transport. Cross-sectional scanning transmission electron microscopy indicates that structural defects such as stacking faults appear in this system. The insulating behavior of the La-doped Sr$_3$Ir$_2$O$_7$ thin-films is presumably due to disorder-induced localization and ineffective electron-doping of La, which brings to light the intriguing difference between epitaxial thin films and bulk single crystals of the iridates., Comment: 4 figures

One-dimensional (1D) quantum systems, which are predicted to exhibit novel states of matter in theory, have been elusive in experiment. Here we report a superlattice method of creating artificial 1D quantum stripes, which offers dimensional tunability from two- to one-dimensions. As a model system, we have fabricated 1D iridium (Ir) stripes using a-axis oriented superlattices of a relativistic Mott insulator Sr2IrO4 and a wide bandgap insulator LaSrGaO4, both of which are crystals with layered structure. In addition to the successful formation of 1D Ir-stripe structure, we have observed 1D quantum-confined electronic states from optical spectroscopy and resonant inelastic x-ray scattering. Since this 1D superlattice approach can be applied to a wide range of layered materials, it opens a new era of 1D science., Comment: 4 figures

An experiment was conducted to assess the effects of polyethylene glycol (PEG-6000) and urea on dry and organic matter digestibility (IVDMD and IVOMD, respectively) and gas production in vitro. Raisin stalk contained 8.6% crude protein, 85% dry matter, 7% ash, 13.95% total extractable phenol (TEPH) and 2.13% total extractable tannin (TET). The experimental treatments were: raisin with no supplementation as control (C); supplemented with 3% urea (U 3%), 5% urea (U 5%) or 3% urea plus 5% PEG (U-PEG) per DM. The rumen liquor fluid was obtained from two ruminal-cannulated fat-tailed sheep. TEPH and TET were determined and in vitro incubation was also conducted. The results indicated that the PEG increased IVOMD and IVDMD. The gas produced from time 0 to 3 and 3 to 6 h of incubation were significantly higher in PEG treatment than that of other groups (P < 0.05). The U-PEG treatment increased the total gas production in 96 h, but it was not statistically significant (P = 0.06) Gas production in 96 h incubation using 300 mg fresh sample was significantly higher than 200 mg sample (P < 0.05). It is concluded that the negative effect of tannin on DM and OM digestibility and also gas production of raisin stalk in vitro could be alleviated by PEG treatment.Key words: Raisin stalk, tannin, polyethylene glycol (PEG), urea, gas production, digestibility, in vitro.

Introduction: The increased risk of hemolytic reactions and erythrocyte recovery delay in ABO incompatible hematopoietic stem cell transplantation (HSCT) are well established. Effects of ABO incompatibility on other transplantation outcomes are evaluated in this study. Subjects and Methods: We prospectively followed 501 patients undergoing allogeneic stem cell transplantation regarding their ABO compatibility groups for a median time of 34.7 months. Patients were studied in minor, major and bidirectional mismatched and matched groups. Results: Mean survival time (OS) was lower in minor mismatched group (p-value= 0.017). Minor and bidirectional mismatched groups received significantly more packed cell units than matched group (p-value < 0.0001 and p-value =0.002, respectively).Mean number of platelet unit infusion was significantly more in major mismatched recipients than matched group (p- value=0.031). Death rate was much more than expected in minor mismatched group. Two cases of PRCA (pure red cell aplasia) were found in major mismatched group. No statistically significant difference was found in the incidence of acute GVHD, chronic GVHD, time to neutrophil recovery, relapse- free survival, non-relapse mortality and relapse rate among groups. Conclusion: In order to prevent complications of ABO-incompatible SCT such as decrease in OS and the need for more transfusions, choosing ABO-compatible donors would improve transplantation outcomes.

Signed graphs are graphs whose edges get signs ±1 and, as for unsigned graphs, they can be studied by means of graph matrices. Here we focus our attention to the largest eigenvalue, also known as the index of the adjacency matrix of signed graphs. Firstly we give some general results on the index variation when the corresponding signed graph is perturbed. Also, we determine signed graphs achieving the minimal or the maximal index in the class of unbalanced unicyclic graphs of order n ≥ 3 .