313 research outputs found

    2\sqrt{2}×\times2R45\sqrt{2}R45^\circ surface reconstruction and electronic structure of BaSnO3_3 film

    Full text link
    We studied surface and electronic structures of barium stannate (BaSnO3_3) thin-film by low energy electron diffraction (LEED), and angle-resolved photoemission spectroscopy (ARPES) techniques. BaSnO3_3/Ba0.96_{0.96}La0.04_{0.04}SnO3_3/SrTiO3_3 (10 nm/100 nm/0.5 mm) samples were grown using pulsed-laser deposition (PLD) method and were \emph{ex-situ} transferred from PLD chamber to ultra-high vacuum (UHV) chambers for annealing, LEED and ARPES studies. UHV annealing starting from 300^{\circ}C up to 550^{\circ}C, followed by LEED and ARPES measurements show 1×\times1 surfaces with non-dispersive energy-momentum bands. The 1×\times1 surface reconstructs into a 2\sqrt{2}×\times2R45\sqrt{2}R45^\circ one at the annealing temperature of 700^{\circ}C where the ARPES data shows clear dispersive bands with valence band maximum located around 3.3 eV below Fermi level. While the 2\sqrt{2}×\times2R45\sqrt{2}R45^\circ surface reconstruction is stable under further UHV annealing, it is reversed to 1×\times1 surface by annealing the sample in 400 mTorr oxygen at 600^{\circ}C. Another UHV annealing at 600^{\circ}C followed by LEED and ARPES measurements, suggests that LEED 2\sqrt{2}×\times2R45\sqrt{2}R45^\circ surface reconstruction and ARPES dispersive bands are reproduced. Our results provide a better picture of electronic structure of BaSnO3_3 surface and are suggestive of role of oxygen vacancies in the reversible 2\sqrt{2}×\times2R45\sqrt{2}R45^\circ surface reconstruction.Comment: 7 pages, 4 figures, Journa

    Patterned Si thin film electrodes for enhancing structural stability

    Get PDF
    A patterned film (electrode) with lozenge-shaped Si tiles could be successfully fabricated by masking with an expanded metal foil during film deposition. Its electrochemical properties and structural stability during the charge-discharge process were examined and compared with those of a continuous (conventional) film electrode. The patterned electrode exhibited a remarkably improved cycleability (75% capacity retention after 120 cycles) and an enhanced structural stability compared to the continuous electrode. The good electrochemical performance of the patterned electrode was attributed to the space between Si tiles that acted as a buffer against the volume change of the Si electrode

    Voiding Dysfunction after Total Mesorectal Excision in Rectal Cancer

    Get PDF
    Purpose The aim of this study was to assess the voiding dysfunction after rectal cancer surgery with total mesorectal excision (TME). Methods This was part of a prospective study done in the rectal cancer patients who underwent surgery with TME between November 2006 and June 2008. Consecutive uroflowmetry, post-voided residual volume, and a voiding questionnaire were performed at preoperatively and postoperatively. Results A total of 50 patients were recruited in this study, including 28 male and 22 female. In the comparison of the preoperative data with the postoperative 3-month data, a significant decrease in mean maximal flow rate, voided volume, and post-voided residual volume were found. In the comparison with the postoperative 6-month data, however only the maximal flow rate was decreased with statistical significance (P=0.02). In the comparison between surgical methods, abdominoperineal resection patients showed delayed recovery of maximal flow rate, voided volume, and post-voided residual volume. There was no significant difference in uroflowmetry parameters with advances in rectal cancer stage. Conclusions Voiding dysfunction is common after rectal cancer surgery but can be recovered in 6 months after surgery or earlier. Abdominoperineal resection was shown to be an unfavorable factor for postoperative voiding. Larger prospective study is needed to determine the long-term effect of rectal cancer surgery in relation to male and female baseline voiding condition

    Fasting Plasma Glucose Cutoff Value for the Prediction of Future Diabetes Development: A Study of Middle-Aged Koreans in a Health Promotion Center

    Get PDF
    We determined optimal fasting plasma glucose (FPG) cutoff values predictive of future diabetes development in a group of middle-aged Koreans who visited a health promotion center. The medical records of 2,964 subjects, who attended the Health Promotion Center in 1998 and 2003, were examined. Subjects were classified into four groups according to their baseline FPG values (Group 1:FPG <5.0 mM/L; Group 2: 5.0≤FPG <5.6 mM/L; Group 3: 5.6≤FPG <6.1 mM/L; Group 4: 6.1≤FPG <7.0 mM/L). No significant difference was observed between Group 1 and Group 2 in terms of diabetes incidence. However, incidence in Group 3 was significantly higher than that in Group 1 [hazards ratio 4.88 (1.65-14.41), p=0.004] and the hazards ratio in Group 4 for diabetes was 36.91 (13.11-103.61), p<0.001, versus Group 1. Receiver operator characteristics curve analysis showed that an FPG of 5.97 mM/L represents the lower limit and gives the best combination of sensitivity and specificity. Our data shows that the risk of future diabetes development started to increase below an FPG of 6.1 mM/L and suggests the importance of efforts to modify diabetes development risk factors at lower impaired fasting glucose levels

    T cell receptors for the HIV KK10 epitope from patients with differential immunologic control are functionally indistinguishable

    Get PDF
    HIV controllers (HCs) are individuals who can naturally control HIV infection, partially due to potent HIV-specific CD8+ T cell responses. Here, we examined the hypothesis that superior function of CD8+ T cells from HCs is encoded by their T cell receptors (TCRs). We compared the functional properties of immunodominant HIV-specific TCRs obtained from HLA-B*2705 HCs and chronic progressors (CPs) following expression in primary T cells. T cells transduced with TCRs from HCs and CPs showed equivalent induction of epitope-specific cytotoxicity, cytokine secretion, and antigen-binding properties. Transduced T cells comparably, albeit modestly, also suppressed HIV infection in vitro and in humanized mice. We also performed extensive molecular dynamics simulations that provided a structural basis for similarities in cytotoxicity and epitope cross-reactivity. These results demonstrate that the differential abilities of HIV-specific CD8+ T cells from HCs and CPs are not genetically encoded in the TCRs alone and must depend on additional factors

    Directly converted patient-specific induced neurons mirror the neuropathology of FUS with disrupted nuclear localization in amyotrophic lateral sclerosis

    Get PDF
    Background Mutations in the fused in sarcoma (FUS) gene have been linked to amyotrophic lateral sclerosis (ALS). ALS patients with FUS mutations exhibit neuronal cytoplasmic mislocalization of the mutant FUS protein. ALS patients fibroblasts or induced pluripotent stem cell (iPSC)-derived neurons have been developed as models for understanding ALS-associated FUS (ALS-FUS) pathology; however, pathological neuronal signatures are not sufficiently present in the fibroblasts of patients, whereas the generation of iPSC-derived neurons from ALS patients requires relatively intricate procedures. Results Here, we report the generation of disease-specific induced neurons (iNeurons) from the fibroblasts of patients who carry three different FUS mutations that were recently identified by direct sequencing and multi-gene panel analysis. The mutations are located at the C-terminal nuclear localization signal (NLS) region of the protein (p.G504Wfs*12, p.R495*, p.Q519E): two de novo mutations in sporadic ALS and one in familial ALS case. Aberrant cytoplasmic mislocalization with nuclear clearance was detected in all patient-derived iNeurons, and oxidative stress further induced the accumulation of cytoplasmic FUS in cytoplasmic granules, thereby recapitulating neuronal pathological features identified in mutant FUS (p.G504Wfs*12)-autopsied ALS patient. Importantly, such FUS pathological hallmarks of the patient with the p.Q519E mutation were only detected in patient-derived iNeurons, which contrasts to predominant FUS (p.Q519E) in the nucleus of both the transfected cells and patient-derived fibroblasts. Conclusions Thus, iNeurons may provide a more reliable model for investigating FUS mutations with disrupted NLS for understanding FUS-associated proteinopathies in ALS
    corecore