412 research outputs found

    Temperature dependence of Mott transition in VO_2 and programmable critical temperature sensor

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    The temperature dependence of the Mott metal-insulator transition (MIT) is studied with a VO_2-based two-terminal device. When a constant voltage is applied to the device, an abrupt current jump is observed with temperature. With increasing applied voltages, the transition temperature of the MIT current jump decreases. We find a monoclinic and electronically correlated metal (MCM) phase between the abrupt current jump and the structural phase transition (SPT). After the transition from insulator to metal, a linear increase in current (or conductivity) is shown with temperature until the current becomes a constant maximum value above T_{SPT}=68^oC. The SPT is confirmed by micro-Raman spectroscopy measurements. Optical microscopy analysis reveals the absence of the local current path in micro scale in the VO_2 device. The current uniformly flows throughout the surface of the VO_2 film when the MIT occurs. This device can be used as a programmable critical temperature sensor.Comment: 4 pages, 3 figure

    Inkjet-Printed Silver CPW with Narrow Gap

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    Inkjet-printed silver coplanar waveguide on a glass substrate with narrow gap is firstly realized by using a selective surface treatment. The measured gap between signal and ground is 16.7 mm. Insertion loss is measured to be 2.04 dB/cm and 4.40 dB/cm at 10 GHz and 40 GHz, respectively

    Real-Life Efficacy and Tolerability of Lacosamide in Pediatric Patients Aged 4 Years or Older with Drug-Resistant Epilepsy

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    Purpose The aim of this study was to evaluate the efficacy and safety of adjunctive lacosamide therapy in pediatric patients aged ≥4 years with drug-resistant epilepsy (DRE). Methods Medical records of children aged 4 to 19 years treated with lacosamide as adjunctive therapy for DRE were retrospectively reviewed. The patients were divided into two groups according to their age at the start of lacosamide treatment: group A (aged 4–15 years) and group B (aged 16–19 years). Changes in seizure frequency from baseline, adverse events, and the retention rate were evaluated at each follow-up visit. Results Sixty-two patients (33 males and 29 females) with a mean age of 11.4 years (range, 4 to 19) were included. The mean duration of follow-up was 20.1±12.9 months. The mean maintenance dose of lacosamide was 6.7±4.8 mg/kg/day. Forty-two patients (67.7%) were responders (≥50% reduction in seizures) with 19.4% (12/62) achieving freedom from seizures. The response rate did not differ significantly between groups A and B (67.6% vs. 68.0%, P=0.795) and was not affected by the concomitant use of sodium channel blockers. Significant independent factors associated with a good response to lacosamide treatment were a shorter duration of epilepsy (P=0.035) and fewer concomitant anti-seizure medications (P=0.002). Mild transient adverse events were observed in 20 patients (32.3%). Conclusion Lacosamide adjunctive therapy was efficacious and tolerated in children aged ≥4 years with DRE. Early use of lacosamide may be helpful for a good response to drug-resistant seizures

    Charge-spin correlation in van der Waals antiferromagenet NiPS3

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    Strong charge-spin coupling is found in a layered transition-metal trichalcogenide NiPS3, a van derWaals antiferromagnet, from our study of the electronic structure using several experimental and theoretical tools: spectroscopic ellipsometry, x-ray absorption and photoemission spectroscopy, and density-functional calculations. NiPS3 displays an anomalous shift in the optical spectral weight at the magnetic ordering temperature, reflecting a strong coupling between the electronic and magnetic structures. X-ray absorption, photoemission and optical spectra support a self-doped ground state in NiPS3. Our work demonstrates that layered transition-metal trichalcogenide magnets are a useful candidate for the study of correlated-electron physics in two-dimensional magnetic material.Comment: 6 pages, 3 figur

    Omega-3 index and smoking in patients with acute ST-elevation myocardial infarction taking statins: a case-control study in Korea

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    <p>Abstract</p> <p>Background</p> <p>n-3 fatty acids and lifestyle also are closely related to risk of CVD. Most Koreans have higher fish consumption than people of Western populations. However, little is known about the recommended value of omega-3 index in Korean patients with acute ST-elevation myocardial infarction (STEMI) taking statins. Here, we tested the hypothesis that lower omega-3 fatty acids and/or smoking are associated with acute STEMI, even though patients with dyslipidemia who were taking statins and who attained their LDL-C goals.</p> <p>Methods</p> <p>We conducted a case-control study in which omega-3 fatty acids and lifestyle factors were determined in 24 consecutive Korean patients taking statins with angiographically confirmed acute STEMI and 68 healthy controls without acute STEMI. The omega-3 index was calculated by the sum of eicosapentaenoic acid and docosahexaenoic acid in erythrocyte membranes. Multivariable adjusted regression analysis was used to assess independent associations between acute STEMI, omega-3 index, and lifestyle factors after adjusting for age, sex, and body mass index (BMI).</p> <p>Results</p> <p>The mean age of total subjects was 59.9 years, and 57.6% of the subjects were male. The omega-3 index was significantly lower in cases (8.83%) than controls (11.13%; P < 0.001); however, total <it>trans</it>-fatty acids were not different between the two groups. The omega-3 index was inversely associated with odds for being a case (OR 0.16 (95% CI 0.03-1.14); P = 0.047), while smoking was positively associated with odds for being a case (OR 6.67 (95% CI 1.77-25.23); P = 0.005) after adjusting for all confounding variables.</p> <p>Conclusion</p> <p>This study shows that relative to controls, acute STEMI cases are more likely to be smokers and to have a lower omega-3 index, even though the cases were taking statins. An omega-3 index of at least 11% and abstinence from smoking are associated with cardioprotection for Koreans.</p

    Impact of very preterm birth and post-discharge growth on cardiometabolic outcomes at school age: a retrospective cohort study

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    Background Adverse metabolic outcomes later in life have been reported among children or young adults who were born as preterm infants. This study was conducted to examine the impact of very preterm/very low birth weight (VP/VLBW) birth and subsequent growth after hospital discharge on cardiometabolic outcomes such as insulin resistance, fasting glucose, and systolic and diastolic blood pressure (BP) among children at 6–8 years of age. Methods This retrospective cohort study included children aged 6–8 years and compared those who were born at < 32 weeks of gestation or weighing < 1,500 g at birth (n = 60) with those born at term (n = 110). Body size, fat mass, BP, glucose, insulin, leptin, adiponectin, and lipid profiles were measured. Weight-for-age z-score changes between discharge and early school-age period were also calculated, and factors associated with BP, fasting glucose, and insulin resistance were analyzed. Results Children who were born VP/VLBW had significantly lower fat masses, higher systolic BP and diastolic BP, and significantly higher values of fasting glucose, insulin, and homeostatic model assessment of insulin resistance (HOMA-IR), compared to children born at term. VP/VLBW was correlated with HOMA-IR and BPs after adjusting for various factors, including fat mass index and weight-for-age z-score changes. Weight-for-age z-score changes were associated with HOMA-IR, but not with BPs. Conclusions Although children aged 6–8 years who were born VP/VLBW showed significantly lower weight and fat mass, they had significantly higher BPs, fasting glucose, HOMA-IR, and leptin levels. The associations of VP/VLBW with cardiometabolic factors were independent of fat mass and weight gain velocity.This research was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHID I), funded by the Ministry of Health & Welfare, Republic of Korea (HI14C3451)

    Controlling ferromagnetic easy axis in a layered MoS2 single crystal

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    We report the effective methods to induce weak ferromagnetism in pristine MoS2 persisting up to room temperature with the improved transport property, which would lead to new spintronics devices. The hydrogenation of MoS2 by heating at 300 degrees C for 1 h leads to the easy axis out of plane, while the irradiation of proton with a dose of 1 x 10(13) P/cm(2) leads to the easy axis in plane. The theoretical modeling supports such magnetic easy axes.open116160Nsciescopu

    A Role of Canonical Transient Receptor Potential 5 Channel in Neuronal Differentiation from A2B5 Neural Progenitor Cells

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    Store-operated Ca2+ entry (SOCE) channels are the main pathway of Ca2+ entry in non-excitable cells such as neural progenitor cells (NPCs). However, the role of SOCE channels has not been defined in the neuronal differentiation from NPCs. Here, we show that canonical transient receptor potential channel (TRPC) as SOCE channel influences the induction of the neuronal differentiation of A2B5+ NPCs isolated from postnatal-12-day rat cerebrums. The amplitudes of SOCE were significantly higher in neural cells differentiated from proliferating A2B5+ NPCs and applications of SOCE blockers, 2-aminoethoxy-diphenylborane (2-APB), and ruthenium red (RR), inhibited their rise of SOCE. Among TRPC subtypes (TRPC1-7), marked expression of TRPC5 and TRPC6 with turned-off TRPC1 expression was observed in neuronal cells differentiated from proliferating A2B5+ NPCs. TRPC5 small interfering RNA (siRNA) blocked the neuronal differentiation from A2B5+ NPCs and reduced the rise of SOCE. In contrast, TRPC6 siRNA had no significant effect on the neuronal differentiation from A2B5+ NPCs. These results indicate that calcium regulation by TRPC5 would play a key role as a switch between proliferation and neuronal differentiation from NPCs

    Predictors of 30-day Mortality and 90-day Functional Recovery after Primary Pontine Hemorrhage

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    The factors related to death and functional recovery after primary pontine hemorrhage (PPH) in Koreans has not been well defined. The authors sought to identify independent predictors of death and functional recovery after PPH using data obtained at a single institute. Data were collected retrospectively on 281 patients with PPH admitted to the Stroke Unit at our hospital between January 1, 2000 and December 31, 2009. Multivariate logistic regression analysis was used to evaluate the associations between selected variables and 30-day mortality and 90-day functional recovery after PPH. One-hundred and ten patients (39.1%) died within 30 days of PPH and 27 patients (9.6%) achieved functional recovery within 90 days. By multivariate analysis, unconsciousness, dilated pupils, abnormal respiration, systolic blood pressure < 100 mmHg, hydrocephalus, and conservative treatment were found to be predictors of 30-day mortality, whereas consciousness, intact motor function, no history of hypertension or diabetes mellitus, intact eye movement, a hematoma volume of < 5 mL, no ventricular hemorrhage, and normally sized ventricle were found to be predictors of 90-day functional recovery. The present findings suggest that systolic hypotension of less than 100 mmHg may predict 30-day mortality and a history of underlying hypertension and diabetes mellitus may predict 90-day functional recovery
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