2,327 research outputs found
In-situ fabrication of cobalt-doped SrFe2As2 thin films by using pulsed laser deposition with excimer laser
The remarkably high superconducting transition temperature and upper critical
field of iron(Fe)-based layered superconductors, despite ferromagnetic material
base, open the prospect for superconducting electronics. However, success in
superconducting electronics has been limited because of difficulties in
fabricating high-quality thin films. We report the growth of high-quality
c-axis-oriented cobalt(Co)-doped SrFe2As2 thin films with bulk
superconductivity by using an in-situ pulsed laser deposition technique with a
248-nm-wavelength KrF excimer laser and an arsenic(As)-rich phase target. The
temperature and field dependences of the magnetization showing strong
diamagnetism and transport critical current density with superior Jc-H
performance are reported. These results provide necessary information for
practical applications of Fe-based superconductors.Comment: 8 pages, 3figures. to be published at Appl. Phys. Let
A pictorial review on clinicopathologic and radiologic features of duodenal gastrointestinal stromal tumors
Duodenal gastrointestinal stromal tumors (GISTs) are rare, and studies on their management are not sufficient. Owing to the complex anatomy of the duodenum and pancreatic head, GISTs can be misdiagnosed as pancreatic head tumors. Surgical resection is the first treatment for localized duodenal GISTs; thus, noninvasive imaging is important for the diagnosis and treatment of GISTs. Computed tomography, magnetic resonance imaging and endoscopic ultrasonography findings can be helpful for the diagnosis of duodenal GISTs and can help differentiate GISTs from other adjacent tumors
Low-Energy Electron Scattering from c-C4F8
Electron collision cross-sections of c-C4F8 were investigated at low energies by using the R-matrix method. The static exchange (SE), static exchange with polarization (SEP), and close-coupling (CC) models of the R-matrix method were used for the calculation of the scattering cross-section. The shape resonance was detected with all the models at around 3~4 eV, and a Feshbach resonance was detected with the SEP model at 7.73 eV, in good agreement with the previous theoretical calculation. The resonance detected was also associated with the experimental dissociative electron attachment of c-C4F8, which displayed the resonances at the same energy range. The cross-sections calculated are important for plasma modeling and applications
Acute perimyocarditis mimicking acute myocardial infarction in a 12-year-old boy with Duchenne muscular dystrophy
Differential diagnosis of chest pain in the pediatric population is important but can be challenging. A 12-year-old boy with Duchenne muscular dystrophy presented with chest pain, cardiac enzyme elevation, and convex ST elevations in the inferior leads with reciprocal ST depression in the anterior leads on electrocardiogram. Echocardiography on admission revealed normal left ventricular function. Suspecting acute myocardial infarction, we performed invasive coronary angiography, which revealed normal coronary arteries. A follow-up electrocardiogram showed an acute pericarditis pattern with concave ST elevations in most leads and PR depression, and follow-up echocardiography revealed global left ventricular dysfunction, suggestive of acute perimyocarditis. Ibuprofen was administered for acute pericarditis, and a continuous milrinone infusion was commenced for myocardial dysfunction. The chest pain improved by the next day, and the ST segment elevations normalized on day 4. Echocardiography on day 9 revealed improved left ventricular function. The patient was discharged on day 11, and he is doing well without chest pain through 12 months of follow-up. The last electrocardiogram showed normal sinus rhythm without ST change. Differential diagnosis of acute myocardial infarction and acute perimyocarditis is important for proper treatment strategies and the different prognoses of these two conditions
Left ventricular dysfunction measured by tissue Doppler imaging and strain rate imaging in hypertensive adolescents
Purpose : Left ventricular (LV) hypertrophy and impaired diastolic function may occur early in systemic hypertension. Diastolic dysfunction is associated with increased cardiovascular risk. Tissue Doppler imaging (TDI)-derived tissue velocity and strain rate are new parameters for assessing diastolic dysfunction. The aim of this study is to determine whether TDI and strain rate imaging (SRI) would improve the ability to recognize early impaired diastolic and systolic functions compared with conventional echocardiography in hypertensive adolescents. Methods : We included 38 hypertensive patients with systolic blood pressure above 140 mmHg or diastolic blood pressure above 90 mmHg. Ejection fraction and myocardial performance index (MPI) were estimated by conventional echocardiography. Peak systolic myocardial velocity, early diastolic myocardial velocity (Em), and peak late diastolic myocardial velocity (Am) were obtained by using TDI and SRI. Results : In the hypertensive group, interventricular septal thickness was significantly increased on M-mode echocardiography. Em/Am was significantly decreased at the mitral valve annulus. Among hypertensive subjects, the E strain rate at basal, mid, and apex was significantly decreased. Systolic strain was significantly decreased at the septum in the hypertensive group. Conclusion : Strain rate might be a useful new parameter for the quantification of both regional and global LV functions and could be used in long-term follow up in hypertensive patients. Early identification by SRI of subjects at risk for hypertensive and ventricular dysfunction may help to stratify risk and guide therapy. Further studies, including serial assessment of LV structure and function in a larger number of adolescents with hypertension, is necessary
Calcified Carcinoma of the Gallbladder with Calcified Nodal Metastasis Presenting as a Porcelain Gallbladder: A Case Report
Porcelain gallbladder is regarded as a risk factor of gallbladder cancer. A porcelain gallbladder with calcified regional lymph nodes was found using computed tomography (CT) and magnetic resonance imaging (MRI) in a 43-year-old man who presented with nausea, vomiting, and abdominal pain. His cholecystectomy specimen showed diffuse wall thickening and contained small gallstones. Histological examination revealed diffuse infiltrative adenocarcinoma with extensive intratumoral calcification (calcified carcinoma). The majority of the calcified material was located within or replaced the tumor glands, and was not found in the stroma. A lymph node was totally replaced with a calcified metastatic adenocarcinoma. To the best of our knowledge, only one case of calcified lymph node metastasis from a calcified carcinoma of the gallbladder has been previously reported in the literature. We herein add a case of calcified carcinoma of the gallbladder with calcified lymph node metastasis, presenting as a porcelain gallbladder on CT and MRI
Resting-state EEG activity related to impulsivity in gambling disorder
Background and aims Impulsivity is a core feature of gambling disorder (GD) and is related to the treatment response. Thus, it is of interest to determine objective neurobiological markers associated with impulsivity in GD. We explored resting-state electroencephalographic (EEG) activity in patients with GD according to the degree of impulsivity. Methods In total, 109 GD subjects were divided into three groups according to Barratt impulsiveness scale-11 (BIS-11) scores: high (HI; 25th percentile of BIS-11 scores, n = 29), middle (MI; 26th–74th percentile, n = 57), and low-impulsivity (LI) groups (75th percentile, n = 23). We used generalized estimating equations to analyze differences in EEG absolute power considering group (HI, MI, and LI), brain region (frontal, central, and posterior), and hemisphere (left, midline, and right) for each frequency band (delta, theta, alpha, beta, and gamma). Results The results indicated that GD patients in the HI group showed decreased theta absolute power, and decreased alpha and beta absolute power in the left, right, particularly midline frontocentral regions. Discussion and conclusions This study is a novel attempt to reveal impulsive features in GD by neurophysiological methods. The results suggest different EEG patterns among GD patients according to the degree of impulsivity, raising the possibility of neurophysiological objective features in GD and helping clinicians in treating GD patients with impulsive features
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