803 research outputs found

    Two-Dimensional Electron Gas at SrTiO 3

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    Two-dimensional electron gas (2DEG) at an oxide interface has been attracting considerable attention for physics research and nanoelectronic applications. Early studies reported the formation of 2DEG at semiconductor interfaces (e.g., AlGaAs/GaAs heterostructures) with interesting electrical properties such as high electron mobility. Besides 2DEG formation at semiconductor junctions, 2DEG was realized at the interface of an oxide heterostructure such as the LaAlO3/SrTiO3 (LAO/STO) heterojunction. The origin of 2DEG was attributed to the well-known “polar catastrophe” mechanism in oxide heterostructures, which consist of an epitaxial LAO layer on a single crystalline STO substrate among proposed mechanisms. Recently, it was reported that the creation of 2DEG was achieved using the atomic layer deposition (ALD) technique, which opens new functionality of ALD in emerging nanoelectronics. This review is focused on the origin of 2DEG at oxide heterostructures using the ALD process. In particular, it addresses the origin of 2DEG at oxide interfaces based on an alternative mechanism (i.e., oxygen vacancies)

    Lack of prognostic significance for major adverse cardiac events of soluble suppression of tumorigenicity 2 levels in patients with ST-segment elevation myocardial infarction

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    Background: Elevation of soluble suppression of tumorigenicity 2 (sST2) is associated with cardiac fibrosis and hypertrophy. Under investigation herein, was whether sST2 level is associated with major adverse cardiac events (MACE) and left ventricular (LV) remodeling after primary percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI). Methods: In total, this study included 184 patients who underwent successful primary PCI. A subsequent guideline-based medical follow-up was included (61.4 ± 11.8 years old, 85% male, 21% with Killip class ≥ I). sST2 concentration correlations with echocardiographic, angiographic, laboratory parameters, and clinical outcomes in STEMI patients were evaluated. Results: The median sST2 level was 60.3 ng/mL; 6 (3.2%) deaths occurred within 1 year. The sST2 level correlated with LV ejection fraction (LVEF) changes from baseline to 6 months (r= –0.273; p = 0.006) after adjustment for echocardiographic parameters including wall motions score index (WMSI). Recovery of LVEF at 6 months was highest in the tertile 1 group (Δ6 months – baseline LVEF; tertile 1, p = 0.001; tertile 2, p = 0.319; tertile 3, p = 0.205). The decrease in WMSI at 6 months was greater in the tertiles 1 and 2 groups than in the tertile 3 group (Δ6 months – baseline WMSI; tertile 1, p = 0.001; tertile 2, p = 0.013; tertile 3, p = 0.055). There was no association between sST2 levels and short-term (log rank p = 0.598) and long-term (p = 0.596) MACE. Conclusions: sST2 concentration have predictive value for LV remodeling on echocardiography in patients with STEMI who underwent primary PCI. However, sST2 concentration was not associated with short-term and long-term MACE

    Assessment of the conventional radial artery with optical coherent tomography after the snuffbox approach

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    Background: This study aimed to evaluate acute injuries of the radial artery (RA) using optical coherence tomography (OCT) in patients who underwent coronary intervention via the snuffbox approach. Methods: Forty-six patients, who underwent coronary intervention and assessment of the conventional RA using OCT via the snuffbox approach, were enrolled from two university hospitals between August 2018 and August 2019. Results: The mean age of the patients was 65.1 years. In this study population, 6-French (Fr) sheaths were used. The mean diameter of the conventional RA was 2.89 ± 0.33 mm, and the mean lumen area of the conventional RA was 6.68 ± 1.56 mm2. Acute injuries of the conventional RA, after the snuffbox approach, were observed in 5 (10.9%) patients. Intimal tear was observed in the RA in 1 (2.2%) case. Intraluminal thrombi, without vessel injuries, were detected in the RA in 4 (8.7%) cases. However, medial dissection was not observed in the OCT analysis. Conclusions: This retrospective OCT-based study showed that the diameter of the conventional RA was 2.89 mm and acute vessel injury of the conventional RA was rare in patients who underwent coronary intervention via the snuffbox approach

    Vitamin D and Exercise Are Major Determinants of Natural Killer Cell Activity, Which Is Age- and Gender-Specific

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    BackgroundThe coronavirus-19 disease (COVID-19) pandemic reminds us of the importance of immune function, even in immunologically normal individuals. Multiple lifestyle factors are known to influence the immune function.ObjectiveThe aim was to investigate the association between NK cell activity (NKA) and multiple factors including vitamin D, physical exercise, age, and gender.MethodsThis was a cross-sectional association study using health check-up and NKA data of 2,095 subjects collected from 2016 to 2018 in a health check-up center in the Republic of Korea. NKA was measured using the interferon-γ (IFN-γ) stimulation method. The association of NKA with 25-(OH)-vitamin D (25(OH)D) and other factors was investigated by multiple logistic regression analysis.ResultsThe average age of subjects was 48.8 ± 11.6 years (52.9% of subjects were female). Among 2,095 subjects, 1,427 had normal NKA (NKA ≥ 500 pg IFN-γ/mL), while 506 had low NKA (100 ≤ NKA < 500 pg/mL), and 162 subjects had very low NKA (NKA < 100 pg/mL). Compared to men with low 25(OH)D serum level (< 20 ng/mL), vitamin D replete men (30–39.9 ng/mL) had significantly lower risk of very low NKA (OR: 0.358; 95% CI: 0.138, 0.929; P = 0.035). In women, both low exercise (OR: 0.529; 95% CI: 0.299, 0.939; P = 0.030) and medium to high exercise (OR: 0.522; 95% CI: 0.277, 0.981; P = 0.043) decreased the risk compared to lack of physical exercise. Interestingly, in men and women older than 60 years, physical exercise significantly decreased the risk. Older-age was associated with increased risk of very low NKA in men, but not in women.ConclusionPhysical exercise and vitamin D were associated with NKA in a gender- and age-dependent manner. Age was a major risk factor of very low NKA in men but not in women

    Cognitive and behavioral effects of lamotrigine and carbamazepine monotherapy in patients with newly diagnosed or untreated partial epilepsy

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    AbstractPurposeIn this prospective study, we compared the long-term cognitive and behavioral effects of lamotrigine (LTG) and carbamazepine (CBZ) in patients with newly diagnosed or untreated partial epilepsy.MethodsThis was a multicenter, open-label, randomized study that compared monotherapy with LTG and CBZ in newly diagnosed or untreated patients with partial epilepsy. We employed an 8-week titration period and a 40-week maintenance period. Neuropsychological tests, Symptom Check List-90, and QOLIE-31 were assessed at baseline, 16 weeks, and 48 weeks after drug treatment. A group-by-time interaction was the primary outcome measure and was analyzed by use of the linear mixed model.ResultsA total of 110 patients were eligible and 73 completed the 48-week study (LTG, n=39; CBZ, n=34). Among the cognitive tests, significant group-by-time interaction was identified only in phonemic fluency of Controlled Oral Word Association Task (p=0.0032) and Stroop Color–Word Interference (p=0.0283), with a significant better performance for LTG group. All other neuropsychological tests included did not show significant group-by-time interactions. Among the subscales of Symptom Check List-90, significant group-by-time interactions were identified in Obsessive-Compulsive (p=0.0005), Paranoid Ideation (p=0.0454), Global Severity Index (p=0.0194), and Positive Symptom Total (p=0.0197), with a significant improvement for CBZ group. QOLIE-31 did not show significant group-by-time interactions.ConclusionOur data suggest that epilepsy patients on LTG have better performance on phonemic fluency and the task of Stroop Color–Word Interference than do patients on CBZ, whereas patients on CBZ had more favorable behavioral effects on two subscales and two global scores of Symptom Check List-90 than did patients on LTG
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