A new strategy for integrating abundant oxygen functional groups into carbon felt electrode for vanadium redox flow batteries

The effects of surface treatment combining corona discharge and hydrogen peroxide (H2O2) on the electrochemical performance of carbon felt electrodes for vanadium redox flow batteries (VRFBs) have been thoroughly investigated. Ahigh concentration of oxygen functional groups has been successfully introduced onto the surface of the carbon felt electrodes by a specially designed surface treatment, which is mainly responsible for improving the energy efficiency of VRFBs. In addition, the wettability of the carbon felt electrodes also can be significantly improved. The energy efficiency of the VRFB cell employing the surface modified carbon felt electrodes is improved by 7% at high current density (148 mA cm(-2)). Such improvement is attributed to the faster charge transfer and better wettability allowed by surface-active oxygen functional groups. Moreover, this method is much more competitive than other surface treatments in terms of processing time, production costs, and electrochemical performance.

A new strategy for integrating abundant oxygen functional groups into carbon felt electrode for vanadium redox flow batteries

The effects of surface treatment combining corona discharge and hydrogen peroxide (H2O2) on the electrochemical performance of carbon felt electrodes for vanadium redox flow batteries (VRFBs) have been thoroughly investigated. A high concentration of oxygen functional groups has been successfully introduced onto the surface of the carbon felt electrodes by a specially designed surface treatment, which is mainly responsible for improving the energy efficiency of VRFBs. In addition, the wettability of the carbon felt electrodes also can be significantly improved. The energy efficiency of the VRFB cell employing the surface modified carbon felt electrodes is improved by 7% at high current density (148 mA cm−2). Such improvement is attributed to the faster charge transfer and better wettability allowed by surface-active oxygen functional groups. Moreover, this method is much more competitive than other surface treatments in terms of processing time, production costs, and electrochemical performance

Electronic structures of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films

We investigated the electronic structure of multiferroic hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films using both optical spectroscopy and first-principles calculations. Using artificially stabilized hexagonal RMnO3, we extended the optical spectroscopic studies on the hexagonal multiferroic manganite system. We observed two optical transitions located near 1.7 eV and 2.3 eV, in addition to the predominant absorption above 5 eV. With the help of first-principles calculations, we attribute the low-lying optical absorption peaks to inter-site transitions from the oxygen states hybridized strongly with different Mn orbital symmetries to the Mn 3d3z2-r2 state. As the ionic radius of the rare earth ion increased, the lowest peak showed a systematic increase in its peak position. We explained this systematic change in terms of a flattening of the MnO5 triangular bipyramid

Measurement of 129 I Radioactivity in Groundwater of Radioactive Waste Disposal Site

The investigation of the environmental radioactivity around the radioactive waste disposal site in Gyeongju is being carried out. The radioactivity of 129 I in groundwater and seaweed are to be measured. The analytical method to measure the radioactivity of 129 I in aqueous media was established. This method contains oxidation-reduction reaction, anion-exchange separation and palladium precipitation. The 129 I radioactivity in the PdI 2 precipitates was measured by using low-energy gamma spectrometer. The counts of peak at 39.6 keV of gamma energy were used for determination of 129 I radioactivity. The chemical recovery was determined by the weights of PdI 2 precipitates. The deionized water and groundwater spiked with 129 I tracer were tested. In the case of deionized water, the relative deviations of measured concentration from spiked one are from 1.1 to 10.7%. The relative deviations of measured radioactivity from spiked one in the groundwater experiments are 2.9 and 3.7%. The measured concentration is in good agreement with spiked one. The groundwater sampled from radioactive waste disposal site was tested. The concentrations of 129 I in the groundwater are below minimum detectable activities of 36.7 and 36.6 mBq/L

A Case of Acute Myocardial Infarction Caused by Distal Embolization of a Left Main Coronary Artery Thrombus

Coronary embolism is an uncommon cause of myocardial infarction. A 48-year-old male presented with typical chest pain of an MI. There was no definite ST segment change on electrocardiogram (ECG) and no elevation of myocardial enzymes. Coronary angiography (CAG) revealed occlusion of the distal left anterior descending coronary artery (dLAD), the distal left circumflex coronary artery (dLCX), the diagonal branch (D) and the obtuse marginal branch (OM), with a large filling defect in the left main coronary artery (LMA) that caused the myocardial infarction. We considered the possibility that coronary embolization was caused by the migration of a thrombus in the LMA during CAG. We did balloon angioplasty in the dLAD, dLCX, OM and D and treated the patient with glycoprotein IIb/IIIa receptor antagonist. However, thrombi remained in the dLAD, OM, and dLCX. After 3 days of anti-thrombotic treatment, follow-up CAG revealed only slight resolution of thrombi in the LAD. After triple antiplatelet agent medication for 1 year, a follow-up CAG showed a resolution of the thrombi in all coronary arteries

Long-term impact of coronavirus disease 2019 pandemic on emergency department utilization in a metropolitan emergency department in Korea

Purpose As coronavirus disease 2019 pandemic has been prolonged, it became crucial to analyze the long-term impact of the pandemic on emergency department (ED) utilization for efficient use of emergency medicine resources. Methods We reviewed the data of children (≤ 18 years) who visited the ED in Daejeon, Korea, from February 2019 through January 2021. This period was dichotomized by February 2020 into the reference and pandemic periods. The latter period was further divided into the early (February-August 2020) and late pandemic periods. Between the reference and pandemic periods, and between the early and late pandemic periods, we respectively compared proportions of children in all patients (including adults), age groups, high acuity (the Korean Triage and Acuity Scale 1-2), diagnostic codes, visits via ambulances, ED length of stay, and ED disposition. Results Compared to the reference and early pandemic periods, the pandemic and late pandemic periods respectively showed changes as follows: proportion of children in all patients (from 29.8% to 19.0% and from 19.8% to 18.1%; all Ps < 0.001), children younger than 5 years (from 56.7% to 49.9% and from 52.1% to 47.4%; all Ps < 0.001), high acuity (from 12.0% to 7.8% [P < 0.001] and from 8.8% to 6.7% [P = 0.004]), “Injury, poisoning and certain other consequences of external causes (S00-T98; from 30.0% to 49.0% and from 48.3% to 49.8%),” and “Diseases of the respiratory system (J00-J99; from 29.6% to 10.3% and from 12.8% to 7.5%).” Increases in the visits via ambulances, ED length of stay, children undergoing intensive care unit hospitalization or death were noted only in comparison between the reference and pandemic periods. Conclusion A long-term impact of the pandemic on ED use may be a decrease in the proportion of young or ill children

Characteristics of primary and immortalized fibroblast cells derived from the miniature and domestic pigs

<p>Abstract</p> <p>Background</p> <p>The pig, <it>Sus scrofa domestica </it>includes both the miniature and commercial domestic breed. These animals have influenced the human life and economies and have been studied throughout history. Although the miniature breeds are more recent and have increasingly been used in a variety of biomedical studies, their cell lines have rarely been established. Therefore, we sought to establish primary and immortal cell lines derived from both the miniature and domestic pig to better enable insight into possible <it>in vivo </it>growth differences.</p> <p>Results</p> <p>The <it>in vitro </it>lifespan of primary domestic pig fibroblast (PF) and miniature pig fibroblast (MPF) cells using a standard 3T3 protocol was determined. Both of the primary PF and MPF cells were shown to have a two-step replicative senescence barrier. Primary MPF cells exhibited a relatively shorter lifespan and slower proliferation rate compared to those of primary PF cells. Beyond senescence barriers, lifespan-extended PF and MPF cells were eventually established and indicated spontaneous cellular immortalization. In contrast to the immortalized PF cells, immortal MPF cells showed a transformed phenotype and possessed more frequent chromosomal abnormalities and loss of p53 regulatory function. The lifespan of primary MPF and PF cells was extended by inactivation of the p53 function using transduction by SV40LT without any detectable senescent phenotype.</p> <p>Conclusion</p> <p>These results suggest that p53 signaling might be a major determinant for the replicative senescence in the MPF cells that have the shorter lifespan and slower growth rate compared to PF cells <it>in vitro</it>.</p

A Case of Right Sided Aortic Arch Combined with Atrial Septal Defect

Right sided aortic arch is an uncommon congenital anomaly. It can be classified into three types, depending on the left aortic arch's degenerating pattern and the branching pattern of the great vessels. It can be associated with major congenital heart disease, depending on the type of right sided aortic arch. We report a case of an 18-years-old female who has right sided aortic arch with atrial septal defect (ASD). In our case, the patient had a right sided aortic arch and aberrant left subclavian artery, also she had ASD (ostium secundum) and moderate tricuspid regurgitation with pulmonary hypertension. The patient was successfully performed patch closure of ASD and tricuspid valve annuloplasty via midline sternotomy. The patient had uneventful postoperative course

Expression of VEGF, HGF, IL-6, IL-8, MMP-9, Telomerase in Peripheral Blood of Patients with Head and Neck Squamous Cell Carcinoma

ObjectivesThis study investigated the telomerase expression in peripheral blood mononuclear cells (PBMCs) and the relationship between the serum level of several soluble factors such as vascular endothelial growth factor (VEGF), hepatocyte growth factor, interleukin (IL)-6, IL-8, and matrix metallopeptidase-9 and the clinicopathological features of patients with head and neck squamous cell carcinoma (HNSCC).MethodsPeripheral blood samples were collected from 50 HNSCC patients and 15 normal controls. The telomerase activity in the PBMCs was measured by Telomere Repeat Amplification Protocols. The serum levels of the soluble factors were analyzed by enzyme-linked immunosorbent assay.ResultsThe expression of telomerase in the PBMCs of HNSCC patients was significantly correlated with the N and American Joint Committee on Cancer (AJCC) stages. The serum VEGF level was significantly higher in the patients with an advanced T stage, N stage and AJCC stage. Serum VEGF was significantly related with the expression of telomerase in the PBMCs. The telomerase expression and the VEGF expression were shown to be independent factors associated with poor survival.ConclusionThe telomerase expression in the PBMCs and the serum VEGF level of HNSCC patients were significantly correlated with the N stage, the AJCC stage and the prognosis