X-ray diffraction and inelastic x-ray scattering measurements of liquid Ba8Ga16Sn30 have been carried out to investigate local structure and atomic dynamics in the liquid. The pair distribution ...function shows shorter and longer interatomic distances in the first coordination shell. The dynamic structure factor exhibits the inelastic excitations on both sides of the quasielastic central peak. The inelastic excitations disperse with increasing the momentum transfer, suggesting the longitudinal acoustic mode. We found a low energy excitation in addition to the longitudinal acoustic excitation in the dynamic structure factor and it reminds us a strong relationship with a rattling motion of a guest (Ba) atom in the solid state. The temperature dependence of the pair distribution function and the longitudinal acoustic excitation energy is very weak in a range from 600 to 900 °C. The result suggests that Ba and other atoms in the melt are located around minimum positions of the effective pair potential approximated as a harmonic one.
Transverse excitations in liquid Sn Hosokawa, S; Munejiri, S; Inui, M ...
Journal of physics. Condensed matter,
03/2013, Letnik:
25, Številka:
11
Journal Article
Recenzirano
Transverse acoustic (TA) excitation modes were observed in inelastic x-ray scattering (IXS) spectra of liquid Sn. The excitation energies and widths of the TA modes are in good agreement with results ...of an ab initio molecular dynamics simulation. By comparing current correlation spectra between the experimental and theoretical results quantitatively, we have concluded that the TA modes can be detected experimentally through the quasi-TA branches in the longitudinal current correlation spectra. The lifetime and propagation length of the TA modes were determined to be ∼0.7 ps and 0.8-1.0 nm, respectively, corresponding to the size of cages formed instantaneously in liquid Sn.
We have measured x-ray diffraction and small-angle x-ray scattering of fluid rubidium by reducing electron density down to the range where the compressibility of the interacting electron gas has been ...theoretically predicted to become negative. Negative compressibility is closely associated with a negative value of the static dielectric function, which makes the screened Coulomb interaction among like charges overall attractive. It was clearly observed that the interatomic distance decreases in spite of the fact that mean interatomic distance increases with expansion, suggesting that an attractive interaction among like charges, ions in this case, is enhanced. These findings indicate that the observed structural features are evidence of the compressional instability of the 3D electron gas.
Photodamaged skin exhibits wrinkles, pigmented spots, dryness and tumors. Solar UV radiation induces cyclobutane pyrimidine dimers (CPD) and further produces base oxidation by reactive oxygen species ...(ROS). ROS are thought to be a major factor to initiate the up‐regulation of matrix metalloproteinases (MMPs) in keratinocytes and fibroblasts via activation of receptor proteins on the cell membrane of keratinocytes and fibroblasts, and to degrade fiber components in dermis, leading to wrinkle formation.
Coenzyme Q10 (CoQ10) was reported to reduce ROS production and DNA damage triggered by UVA irradiation in human keratinocytes in vitro. Further, CoQ10 was shown to reduce UVA‐induced MMPs in cultured human dermal fibroblasts. We speculated that UVB radiation‐induced cytokine production in keratinocytes may be inhibited by CoQ10, resulting in the reduction of MMPs in fibroblasts leading to wrinkle reduction. Our in vitro studies showed that UVB‐induced IL‐6 production of normal human keratinocyte (NHKC) decreased in the presence of CoQ10. Furthermore, MMP‐1 production of fibroblasts cultured with the medium containing CoQ10 collected from UVB‐irradiated NHKC significantly decreased during 24 h culture. In the clinical trial study, we found that the use of 1% CoQ10 cream for five months reduced wrinkle score grade observed by a dermatologist. Taken together, our results indicate that CoQ10 may inhibit the production of IL‐6 which stimulate fibroblasts in dermis by paracrine manner to up‐regulate MMPs production, and contribute to protecting dermal fiber components from degradation, leading to rejuvenation of wrinkled skin.
Inelastic x-ray scattering spectra of fluid S were measured from 403 K near the melting point to 1343 K in the supercritical region at 25 MPa. Although the dynamic structure factor in the ...supercritical region exhibits a single peak profile, the spectrum includes collective inelastic excitations besides the quasielastic component. The acoustic excitation energy in the supercritical region is close to the one predicted by the sound speed in the fluid consisting of S8 molecules and the observed excitation energies of the stretching modes in S molecules suggest that few fraction of S2 molecules in the supercritical region near the liquid-vapor critical point. This result indicates that the nearest neighbor coordination number in the supercritical fluid S obtained by x-ray diffraction Inui et al., J. Phys. Conf. Ser. 98 (2008) 012008 was underestimated.
•The dynamic structure factor of fluid sulfur was obtained up to 1343 K and 25 MPa in the supercritical region.•The inelastic excitations arising from molecular vibrational modes are observed.•Few fractions of S dimmers among S molecules in the supercritical region are estimated.
Abstract Background The purpose of this study was to present our experience with robot-assisted radical prostatectomy (RARP) for localized prostate cancer in renal transplant recipients (RTRs) and to ...determine the feasibility and efficacy of RARP in these patients. Methods We retrospectively reviewed the medical records of 236 patients who underwent RARP for localized prostate cancer at our institution between August 2011 and July 2015 and identified 3 patients who were RTRs. We reviewed the available clinical data of the 3 patients. Results All patients underwent RARP successfully without any major complications. The mean operation time was 162 minutes (range, 127–195 minutes). The mean estimated blood loss was 52 mL (range, 30–75 mL); therefore, the patients did not need any perioperative blood transfusion. In all cases, graft function, as determined according to the serum creatinine level, was stable during and after the operation. Pathological examination showed negative surgical margins with organ-confined disease in all patients. Conclusions We reported 3 RTRs with localized prostate cancer who were treated with RARP. RARP might be a feasible and effective minimally invasive technique for the treatment of localized prostate cancer in carefully selected RTRs.
The transverse acoustic excitation modes were detected by inelastic x-ray scattering in liquid Ga in the Q range above 9 nm(-1) although liquid Ga is mostly described by a hard-sphere liquid. An ab ...initio molecular dynamics simulation clearly supports this finding. From the detailed analysis for the S(Q,omega) spectra with a good statistic quality, the lifetime of 0.5 ps and the propagating length of 0.4-0.5 nm can be estimated for the transverse acoustic phonon modes, which may correspond to the lifetime and size of cages formed instantaneously in liquid Ga.
A newly designed magnifying endoscope featuring an endocytoscopy function provided by ultrahigh magnification was evaluated in a pilot study in patients with various types of benign and malignant ...pathology in the esophagus.
Seventy-five consecutive patients were included in the study from 15 March to 21 December 2005. Twenty-nine patients with specific esophageal lesions that had been detected by regular or narrow-band imaging, or both, were further evaluated using endocytoscopy, followed by tissue biopsy or resection. During the endocytoscopic examinations, the esophageal mucosa was stained with 0.5 % methylene blue. The endocytoscopic findings were graded from 1 to 5 in an endocytoscopic atypia (ECA) classification. The final histopathological diagnoses based on biopsies or resected specimens were as follows: category 1 in the Vienna classification, n = 4; category 2, n = 6; category 3, n = 1; category 4, n = 10; and category 5, n = 7. The endocytoscopic diagnoses were compared with the histopathological diagnoses.
Clear endocytoscopic images were obtained in all cases. In definitely malignant lesions, the cell nuclei had an enlarged and irregularly arranged appearance (grade ECA 5). The positive predictive value for malignancy (grades ECA 4 and 5) was 94 %; the false-negative rate was 16.7 %, and the false-positive rate was 6.3 %. The overall accuracy of endocytoscopy for differentiating between nonmalignant tissue (categories 1 - 3 in the Vienna classification) and malignant tissue (categories 4 and 5) was 82 %.
These preliminary results suggest that incorporating endocytoscopy facilities into a standard endoscope may be helpful in characterizing tissue in a variety of esophageal lesions. The potential clinical impact of this method in relation to other gastrointestinal organs requires further study.
We investigate the dynamic structure factor of the melt of the well known glass former, As2Se3, using inelastic x-ray scattering for temperatures, T, K and momentum transfers Q from nm−1. An anomaly ...was observed at Q = 2.7 nm−1 ( K) with, in the context of a simple model, both an abrupt change in frequency and an increased linewidth reminiscent of an anti-crossing in a solid. Comparison with structural information from reverse Monte Carlo modeling of x-ray diffraction data allows us to associate the disappearance of the anomaly at higher temperatures with a drop in the number of mechanical constraints per atom, nmc, to reminiscent of the threshold applicable for glass formation in rigidity theory. It is inferred that the surprising jump in the dispersion in the liquid may be correlated with a stiffness transition in a network glass.
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