Synthesis of Silicon Nanoparticles and Nanowires by a Nontransferred Arc Plasma System

Silicon nanomaterials were synthesized from solid silicon powder in microsize using a nontransferred arc plasma system. Synthesized silicon nanomaterials were sphere or wire in morphology according to the input power of arc plasma, the flow rate of plasma forming gas, and the collecting position of product. The product was spherical nanoparticles at a high input power for complete evaporation, while it was nanowires at a relatively low input power. The mean diameter of synthesized silicon nanoparticles was increased from 20.52 nm to 40.01 nm by increasing the input power from 9 kW to 13 kW. On the other hand, the diameter of silicon nanowires was controllable by changing the flow rate of plasma forming gas. The mean diameter of silicon nanowires was increased from 16.69 nm to 23.03 nm by decreasing the plasma forming gas flow rate from 15 L/min to 12 L/min

Spectrum of patients with hypermethioninemia based on neonatal screening tests over 14 years

Purpose : The neonatal screening test for homocystinuria primarily measures methionine by using a dried blood specimen. We investigated the incidence and clinical manifestations of homocystinuria, isolated hypermethioninemia, and transient hypermethioninemia among patients with hypermethioninemia on a neonatal screening test. Methods : We performed a retrospective study of 58 patients transferred to Shoonchunhyang Hospital because of hypermethioninemia on a neonatal screening test between January 1996 and August 2009. We analyzed the level of amino acid from plasma and urine, as well as blood homocysteine. Results : Almost half of the 58 patients were identified as normal. Whereas only 3 (5.1%) patients were identified as having homocystinuria, about 20.7% (12 cases) of the patients had isolated hypermethioninemia. The ages of these two groups at initial detection of hypermethioninemia on plasma amino acid analysis were 50.0¡?#?2.5; days and 34.9¡?#?3.5; days, respectively. Both groups were put on diets, and they showed a normal developmental course as a result of early diagnosis and treatment. Conclusion : Hypermethioninemia without homocystinuria, referred to as isolated hypermethioninemia, was also detected. Thus, the impact of hypermethioninemia on a neonatal screening test should be carefully evaluated through analysis of amino acid levels from blood and urine, and we need to detect and treat an early stage of isolated hypermethioninemia as well as homocystinuria

Focal Nodular Hyperplasia with Retraction of Liver Capsule: A Case Report

Focal nodular hyperplasia (FNH) is characterized by the presence a central scar with radiating fibrous septa. Our case had a capsular retraction, which was the result of an extension of the central scar to the surface. In addition, a hypointense scar on the T2-weighted image and a minimal enhancing central scar on the enhanced T1-weighted image, which was due to dense, sclerotic collagenous tissue, were observed. We report the first case of FNH with a capsular retraction

Prospective analysis of video head impulse tests in patients with acute posterior circulation stroke

BackgroundVideo head impulse tests (vHITs), assessing the vestibulo-ocular reflex (VOR), may be helpful in the differential diagnosis of acute dizziness. We aimed to investigate vHITs in patients with acute posterior circulation stroke (PCS) to examine whether these findings could exhibit significant abnormalities based on lesion locations, and to evaluate diagnostic value of vHIT in differentiating dizziness between PCS and vestibular neuritis (VN).MethodsWe prospectively recruited consecutive 80 patients with acute PCS and analyzed vHIT findings according to the presence of dorsal brainstem stroke (DBS). We also compared vHIT findings between PCS patients with dizziness and a previously studied VN group (n = 29). Receiver operating characteristic (ROC) analysis was performed to assess the performance of VOR gain and its asymmetry in distinguishing dizziness between PCS and VN.ResultsPatients with PCS underwent vHIT within a median of 2 days from stroke onset. Mean horizontal VOR gain was 0.97, and there was no significant difference between PCS patients with DBS (n = 15) and without (n = 65). None exhibited pathologic overt corrective saccades. When comparing the PCS group with dizziness (n = 40) to the VN group (n = 29), patients with VN demonstrated significantly lower mean VOR gains in the ipsilesional horizontal canals (1.00 vs. 0.57, p < 0.001). VOR gain and their asymmetry effectively differentiated dizziness in the PCS from VN groups, with an area under the ROC curve of 0.86 (95% CI 0.74–0.98) and 0.91 (95% CI 0.83–0.99, p < 0.001), respectively.ConclusionSignificantly abnormal vHIT results were rare in patients with acute PCS, even in the presence of DBS. Moreover, vHIT effectively differentiated dizziness between PCS and VN, highlighting its potential for aiding differential diagnosis of acute dizziness

Isolation of Endothelial Progenitor Cells from Cord Blood and Induction of Differentiation by Ex Vivo Expansion

Endothelial progenitor cells (EPCs) have been reported to possess the capacity to colonize vascular grafts and hold promise for therapeutic neovascularization. However, limited quantities of EPCs have been the major factor impeding effective research on vasculoangiogenesis. In this study, cytokine and culture conditions necessary for the provision of large quantities of endothelial cells (ECs) were investigated. Cord blood was collected from 18 normal full-term deliveries and CD34+ cells were isolated by MACS system (Miltenyi Biotech, Bergish-Gladbach, Germany). To evaluate the effect of cytokines, CD34+ cells were cultured with various cytokine combinations, such as stem cell factor (SCF), flt3-ligand (FL), and thrombopoietin (TPO) with vascular endothelial growth factor (VEGF), interleukin-1β, fibroblast growth factor-basic (FGF-b) as basic cytokines. The quantities of non-adherent and adherent cells were the greatest with SCF, FL and TPO. The addition of TPO to all other cytokines significantly increased the number of non-adherent and adherent cells (p < 0.05, Wilcoxon rank sum test). After four weeks of culture, adherent cells expressed endothelial specific markers such as KDR, CD31 and CD62E. Typical morphology of ECs was observed during culture, such as cord-like structure and cobblestone appearance, suggesting that the adherent cells were consistent with ECs. In this study, the experimental conditions that optimize the production of ECs for therapeutic neovascularization were described. And it was possibly suggested that TPO plays a major role in differentiation from EPCs to ECs

Clinical Role of Interstitial Pneumonia in Patients with Scrub Typhus: A Possible Marker of Disease Severity

Interstitial pneumonia (IP) frequently occurs in patients with scrub typhus, but its clinical significance is not well known. This study was designed to evaluate interstitial pneumonia as a marker of severity of the disease for patients with scrub typhus. We investigated clinical parameters representing the severity of the disease, and the chest radiographic findings for 101 patients with scrub typhus. We then compared these clinical factors between patients with and without IP. We also studied the relationship between IP and other chest radiographic findings. The chest radiography showed IP (51.4%), pleural effusion (42.6%), cardiomegaly (14.9%), pulmonary alveolar edema (20.8%), hilar lymphadenopathy (13.8%) and focal atelectasis (11.8%), respectively. The patients with IP (n=52) had higher incidences in episode of hypoxia (p=0.030), hypotension (p=0.024), severe thrombocytopenia (p=0.036) and hypoalbuminemia (p=0.013) than the patients without IP (n=49). The patients with IP also had higher incidences of pleural effusion (p<0.001), focal atelectasis (p=0.019), cardiomegaly (p<0.001), pulmonary alveolar edema (p=0.011) and hilar lymphadenopathy (p<0.001) than the patients without IP. Our data suggest that IP frequently occurs for patients with scrub typhus and its presence is closely associated with the disease severity of scrub typhus

Corrected QTc interval combined with troponin value and mortality in acute ischemic stroke

Background and PurposeCardiac biomarkers including, elevated troponin (ET) and prolonged heart rate-corrected QT (PQTc) interval on electrocardiography are known to frequent and have a prognostic significance in patients with acute ischemic stroke (AIS). However, it is still challenging to practically apply the results for appropriate risk stratification. This study evaluate whether combining ET and PQTc interval can better assess the long-term prognosis in AIS patients.MethodsIn this prospectively registered observational study between May 2007 and December 2011, ET was defined as serum troponin-I ≥ 0.04 ng/ml and PQTc interval was defined as the highest tertile of sex-specific QTc interval (men ≥ 469 ms or women ≥ 487 ms).ResultsAmong the 1,668 patients [1018 (61.0%) men; mean age 66.0 ± 12.4 years], patients were stratified into four groups according to the combination of ET and PQTc intervals. During a median follow-up of 33 months, ET (hazard ratio [HR]: 4.38, 95% confidence interval [CI]: 2.94–6.53) or PQTc interval (HR: 1.53, 95% CI: 1.16–2.01) alone or both (HR: 1.77, 95% CI: 1.16–2.71) was associated with increased all-cause mortality. Furthermore, ET, PQTc interval alone or both was associated with vascular death, whereas only ET alone was associated with non-vascular death. Comorbidity burden, especially atrial fibrillation and congestive heart failure, and stroke severity gradually increased both with troponin value and QTc-interval.ConclusionsIn patients with AIS, combining ET and PQTc interval on ECG enhances risk stratification for long-term mortality while facilitating the discerning ability for the burden of comorbidities and stroke severity