Reverse Monte Carlo modeling for local structures of noble metal nanoparticles using high-energy XRD and EXAFS

Reverse Monte Carlo (RMC) modeling based on the total structure factor S(Q) obtained from high-energy X-ray diffraction (HEXRD) and the k³χ(k) obtained from extended X-ray absorption fine structure (EXAFS) measurements was employed to determine the 3-dimensional (3D) atomic-scale structure of Pt, Pd, and Rh nanoparticles, with sizes less than 5 nm, synthesized by photoreduction. The total structure factor and Fourier-transformed PDF showed that the first nearest neighbor peak is in accordance with that obtained from conventional EXAFS analysis. RMC constructed 3D models were analyzed in terms of prime structural characteristics such as metal-to-metal bond lengths, first-shell coordination numbers and bond angle distributions. The first-shell coordination numbers and bond angle distributions for the RMC-simulated metal nanoparticles indicated a face-centered cubic (fcc) structure with appropriate number density. Modeling disorder effects in these RMC-simulated metal nanoparticles also revealed substantial differences in bond-length distributions for respective nanoparticles.

3-Dimensional atomic-scale structure of metal nanoparticles obtained by RMC-based simulations using HEXRD and EXAFS data.     

In vivo bioluminescence imaging of magnetically targeted bone marrow‐derived mesenchymal stem cells in skeletal muscle injury model

The purpose of this study is to clarify the kinetics of transplanted mesenchymal stem cells (MSCs) in rat skeletal muscle injury model and the contribution of the magnetic cell delivery system to muscle injury repair. A magnetic field generator was used to apply an external magnetic force to the injury site of the tibia anterior muscle, and 1 × 10⁶ MSCs labeled with ferucarbotran–protamine complexes, which were isolated from luciferase transgenic rats, were injected into the injury site. MSCs were injected with and without an external magnetic force (MSC M+ and MSC M? groups, respectively), and phosphate‐buffered saline was injected into injury sites as a control. In vivo bioluminescence imaging was performed immediately after the transplantation and, at 12, 24, and 72 h, and 1 and 4 weeks post‐transplantation. Also, muscle regeneration and function were histologically and electromechanically evaluated. In vivo bioluminescence imaging showed that the photon of the MSC M+ group was significantly higher than that of the MSC M? group throughout the observation period. In addition, muscle regeneration and function in the MSC M+ group was histologically and functionally better than that of the MSC M? group. The results of our study indicated that magnetic cell delivery system may be of use in directing the transplanted MSCs to the injury site to promote skeletal muscle regeneration. © 2012 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31: 754–759, 2013     

Determinants of reflux perception in patients with non-erosive reflux disease who have reflux-related symptoms on potassium-competitive acid blocker therapy

Esophagus - This study investigated potential determinants of reflux perception in patients with non-erosive reflux disease (NERD) who had reflux-related symptoms on potassium-competitive acid...     

Clinicopathological study of nonalcoholic fatty liver disease in Japan: the risk factors for fibrosis

Background/Aims: We evaluated patients with nonalcoholic fatty liver disease (NAFLD) and compared the clinical and pathological features to identify the risk factors for NAFLD with severe fibrosis. Methods: One hundred and eighty‐two patients with biopsy‐confirmed NAFLD from various medical centres were recruited into this study. Results: The variables that were significantly associated with severe steatosis were male gender (mild:severe=36%:53%, P=0.02), younger age (mild:severe=57%:82%, P>0.001) and absence of type 2 diabetes (mild:severe=43%:71%, P>0.001). There was no significant difference in the degree of inflammation among the clinical groups. The variables that were significantly associated with severe fibrosis were female gender (mild:severe=54%:84%, P=0.002), older age (≥60 years old) (mild:severe=29%:53%, P=0.020), type 2 diabetes (mild:severe=42%:71%, P=0.020) and hypertension (mild:severe=24%:53%, P=0.002). Although there were more obese patients in the group with severe fibrosis, the association was not statistically significant (mild:severe=67%:78%, P=0.229). The prevalence of high serum triglyceride levels was similar between the two groups. The N (Nippon) score (total number of risk factor) could significantly predict severe fibrosis in NAFLD patients (1.48 ± 1.14 vs. 2.66 ± 0.94, P<0.001). Conclusions: The N score can be used to predict severe fibrosis in cases of NAFLD.