92 research outputs found

    Oxygen Partial Pressure during Pulsed Laser Deposition: Deterministic Role on Thermodynamic Stability of Atomic Termination Sequence at SrRuO3/BaTiO3 Interface

    Full text link
    With recent trends on miniaturizing oxide-based devices, the need for atomic-scale control of surface/interface structures by pulsed laser deposition (PLD) has increased. In particular, realizing uniform atomic termination at the surface/interface is highly desirable. However, a lack of understanding on the surface formation mechanism in PLD has limited a deliberate control of surface/interface atomic stacking sequences. Here, taking the prototypical SrRuO3/BaTiO3/SrRuO3 (SRO/BTO/SRO) heterostructure as a model system, we investigated the formation of different interfacial termination sequences (BaO-RuO2 or TiO2-SrO) with oxygen partial pressure (PO2) during PLD. We found that a uniform SrO-TiO2 termination sequence at the SRO/BTO interface can be achieved by lowering the PO2 to 5 mTorr, regardless of the total background gas pressure (Ptotal), growth mode, or growth rate. Our results indicate that the thermodynamic stability of the BTO surface at the low-energy kinetics stage of PLD can play an important role in surface/interface termination formation. This work paves the way for realizing termination engineering in functional oxide heterostructures.Comment: 27 pages, 6 figures, Supporting Informatio

    Crotonis Fructus

    Get PDF
    Introduction. Crotonis fructus (CF) is the mature fruit of Croton tiglium L. and has been used for the treatment of gastrointestinal disturbance in Asia. It is well known that the main component of CF is croton oil (CO). The present study is to investigate the effects of CF extracts (CFE) and CO on lipolysis in OP9 adipocytes. Methods. Glycerol release to the culture supernatants was used as a marker of adipocyte lipolysis. Results. Treatment with various concentrations of CFE and CO stimulates glycerol release in a dose-dependent manner. The increase in glycerol release by CFE is more potent than isoproterenol, which is a β-adrenergic agonist as a positive control in our system. The increased lipolysis by CFE and CO was accompanied by an increase of phosphorylated hormone sensitive lipase (pHSL) but not nonphosphorylated HSL protein and mRNA. Pretreatment with H89, which is a protein kinase A inhibitor, significantly abolished the CFE- and CO-induced glycerol release in OP9 adipocytes. These results suggest that CFE and CO may be a candidate for the development of a lipolysis-stimulating agent in adipocytes

    Cox-2 and IL-10 Polymorphisms and Association with Squamous Cell Carcinoma of The Head and Neck in a Korean Sample

    Get PDF
    Cyclooxygenase-2 (COX-2) is involved in inflammation and carcinogenesis. Interleukin-10 (IL-10) is also regarded as anti-inflammatory factors with the multi-functional ability to positively and negatively influence functional immunity and tumor development. Genetic polymorphisms of COX-2 and IL-10 might contribute to the development of squamous cell carcinoma of the head and neck (SCCHN). The purpose of this study was to evaluate the association of COX-2 and IL-10 single nucleotide polymorphisms (SNPs) with the risk of SCCHN in a Korean sample. We analyzed the COX-2 SNPs, -1329A>G, +1266C>T, and +6365T>C, and the IL-10 SNPs, -1082A>G, +920T>G, and +3917T>C, in 290 Korean SCCHN patients and 358 healthy controls. There was no significant association between the risk of SCCHN and the three COX-2 or three IL-10 SNPs. We analyzed three haplotypes (ht1, ht2, ht3) for COX-2 and found that COX-2 ht3+/+ was associated with a decreased risk of SCCHN in a Korean sample, compared with the COX-2 ht3 -/- genotype (P=0.03). Two haplotypes (ht1, ht2) of IL-10 were analyzed and there was no statistical significance in the distribution of haplotypes. Based on these results, the COX-2 haplotype ht3 can be used as a molecular biomarker to predict low risk groups of SCCHN in a Korean sample

    XPD Polymorphisms and Risk of Squamous Cell Carcinoma of the Head and Neck in a Korean Sample

    Get PDF
    Objectives. XPD is a major player in nucleotide excision repair, which is one of the basic pathways of DNA repair. The objective of this study was to investigate the association of XPD single nucleotide polymorphisms (SNPs) and the risk of squamous cell carcinoma of the head and neck (SCCHN) in Koreans. Methods. We performed XPD +23591G>A and +35931A>C genotyping in 290 SCCHN patients and 358 controls. Results. The frequencies of the XPD +23591G>A (GG/GA/AA) genotypes were 89.0%/11.0%/0% in the patients and 90.3%/8.8%/0.9% in the controls, respectively. The odds ratio (OR) of the XPD +23591 GA genotype was 1.94 (0.92 to 4.08) in reference to the GG genotype. The frequencies of the XPD -4-35931A>C (AA/AC/CC) genotypes were 86.9%/12.0%/1.1% in the patients and 85.6%/13.8%/0.6% in the controls, respectively. The OR of the XPD +35931 AC and CC genotypes were 0.98 (0.51 to 1.88) and 2.68 (0.71 to 10.1), respectively, in reference to the AA genotype. On the subgroup analyses according to the smoking and drinking statuses, the SNPs and haplotypes of XPD showed no statistically significant association with the risk of SCCHN. Conclusion. The results of this study suggest that the XPD +23591G>A and +35931A>C SNPs are not associated with the risk of SCCHN in Koreans; however, a further study with a larger number of subjects is necessary to verify this conclusion

    Electrocardiographic Left Ventricular Hypertrophy and Outcome in Hemodialysis Patients

    Get PDF
    BACKGROUND AND AIMS: Electrocardiography (ECG) is the most widely used initial screening test for the assessment of left ventricular hypertrophy (LVH), an independent predictor of cardiovascular mortality in patients with end-stage renal disease (ESRD). However, traditional ECG criteria based only on voltage to detect LVH have limited clinical utility for the detection of LVH because of their poor sensitivity. METHODS: This prospective observational study was undertaken to compare the prognostic significance of commonly used ECG criteria for LVH, namely Sokolow-Lyon voltage (SV) or voltage-duration product (SP) and Cornell voltage (CV) or voltage-duration product (CP) criteria, and to investigate the association between echocardiographic LV mass index (LVMI) and ECG-LVH criteria in ESRD patients, who consecutively started maintenance hemodialysis (HD) between January 2006 and December 2008. RESULTS: A total of 317 patients, who underwent both ECG and echocardiography, were included. Compared to SV and CV criteria, SP and CP criteria, respectively, correlated more closely with LVMI. In addition, CP criteria provided the highest positive predictive value for echocardiographic LVH. The 5-year cardiovascular survival rates were significantly lower in patients with ECG-LVH by each criterion. In multivariate analyses, echocardiographic LVH [adjusted hazard ratio (HR): 11.71; 95% confidence interval (CI): 1.57-87.18; P = 0.016] and ECG-LVH by SP (HR: 3.43; 95% CI: 1.32-8.92; P = 0.011) and CP (HR: 3.07; 95% CI: 1.16-8.11; P = 0.024) criteria, but not SV and CV criteria, were significantly associated with cardiovascular mortality. CONCLUSIONS: The product of QRS voltage and duration is helpful in identifying the presence of LVH and predicting cardiovascular mortality in incident HD patients

    Feedforward Plus Feedback Control of an Electro-Hydraulic Valve System Using a Proportional Control Valve

    No full text
    The output feedback signal of the electro-hydraulic valve system (EHVS) affects the activation of its right or left envelope function; thus, even weak measurement noise can cause high-frequency switching between the two envelope functions, leading to chattering in the control input. Consequently, feedforward and feedback controllers in a cascaded configuration generate undesirable chattering in the output signal. We propose a practical and reliable control approach for an EHVS actuated by a proportional control valve. The proposed controller has a parallel structure comprising an inverse generalized Prandtl–Ishlinskii (P–I) model-based feedforward controller, with both hydraulic dead-zone and flow saturation limits, for compensating asymmetric hysteretic behavior. Further, the proposed controller comprises a robust proportional-integral-derivative (PID) feedback controller for achieving robustness against disturbances and noises. The proposed parallel structure is independent of the output feedback of the EHVS. Moreover, the proposed robust PID feedback controller guarantees EHVS stability by precisely selecting the cutoff frequency for the sensitivity and complementary sensitivity functions based on the amplitude spectrum of the inverse-model-based feedforward compensation error. The results verify the high reliability of the proposed EHVS control scheme for the precise control of an EHVS actuated by a proportional control valve in practice
    corecore