Metal-Insulator Phase Transition in Quasi-One-Dimensional VO₂Structures

The metal-insulator transition (MIT) in strongly correlated oxides has attracted considerable attention from both theoretical and experimental researchers. Among the strongly correlated oxides, vanadium dioxide (VO2) has been extensively studied in the last decade because of a sharp, reversible change in its optical, electrical, and magnetic properties at approximately 341 K, which would be possible and promising to develop functional devices with advanced technology by utilizing MITs. However, taking the step towards successful commercialization requires the comprehensive understanding of MIT mechanisms, enabling us to manipulate the nature of transitions. In this regard, recently, quasi-one-dimensional (quasi-1D) VO2structures have been intensively investigated due to their attractive geometry and unique physical properties to observe new aspects of transitions compared with their bulk counterparts. Thus, in this review, we will address recent research progress in the development of various approaches for the modification of MITs in quasi-1D VO2structures. Furthermore, we will review recent studies on realizing novel functional devices based on quasi-1D VO2structures for a wide range of applications, such as a gas sensor, a flexible strain sensor, an electrical switch, a thermal memory, and a nonvolatile electrical memory with multiple resistance.</jats:p

Role of G{alpha}12 and G{alpha}13 as Novel Switches for the Activity of Nrf2, a Key Antioxidative Transcription Factor

G{alpha}12 and G{alpha}13 function as molecular regulators responding to extracellular stimuli. NF-E2-related factor 2 (Nrf2) is involved in a protective adaptive response to oxidative stress. This study investigated the regulation of Nrf2 by G{alpha}12 and G{alpha}13. A deficiency of G{alpha}12, but not of G{alpha}13, enhanced Nrf2 activity and target gene transactivation in embryo fibroblasts. In mice, G{alpha}12 knockout activated Nrf2 and thereby facilitated heme catabolism to bilirubin and its glucuronosyl conjugations. An oligonucleotide microarray demonstrated the transactivation of Nrf2 target genes by G{alpha}12 gene knockout. G{alpha}12 deficiency reduced Jun N-terminal protein kinase (JNK)-dependent Nrf2 ubiquitination required for proteasomal degradation, and so did G{alpha}13 deficiency. The absence of G{alpha}12, but not of G{alpha}13, increased protein kinase C {delta} (PKC {delta}) activation and the PKC {delta}-mediated serine phosphorylation of Nrf2. G{alpha}13 gene knockout or knockdown abrogated the Nrf2 phosphorylation induced by G{alpha}12 deficiency, suggesting that relief from G{alpha}12 repression leads to the G{alpha}13-mediated activation of Nrf2. Constitutive activation of G{alpha}13 promoted Nrf2 activity and target gene induction via Rho-mediated PKC {delta} activation, corroborating positive regulation by G{alpha}13. In summary, G{alpha}12 and G{alpha}13 transmit a JNK-dependent signal for Nrf2 ubiquitination, whereas G{alpha}13 regulates Rho-PKC {delta}-mediated Nrf2 phosphorylation, which is negatively balanced by G{alpha}12

CO-COMBUSTION OF KOREAN ANTHRACITE WITH VARIOUS FUELS IN A COMMERCIAL CIRCULATING FLUIDIZED BED BOILER

The effect of co-combustion of various fuels such as bituminous coal, imported anthracite, RDF and wood pellet with Korean anthracite on the combustion and environmental performance was observed in the commercial CFB boiler. The temperatures in the furnace and cyclones exits decreased with increasing the cocombustion ratio of the bituminous coal, which could achieve more stable operation of the CFB boiler. During Co-combustion of the RDF and wood pellets, the temperature of the furnace exit increased slightly with due to volatiles re-combustion which could restrict to increase the co-combustion ratio of the RDF and wood pellets in the CFB boiler. It was limited for the electrostatic precipitator (EP) to maintain the stable operation above 5% of the RDF co-combustion ratio according to decrease of the output voltages of the EP collecting plate. High content of CaO in the RDF and the wood pellet made the required limestone flow rates decrease. The emissions NOx, HCl and dioxin during co-combustion of the RDF and wood pellets did not change appreciably when compared with firing only Korean anthracite, which were also low enough to meet Korean regulation limits. On the other hand, chlorine content in the ashes emitted from the boiler increased gradually with increasing the RDF co-combustion ratio because of absorption by limestone. The co-combustion of various fuels with Korean anthracite in the commercial CFB boiler was found to be of great use up to a certain co-combustion ratio of each fuel without the technical and environmental problems

Helicobacter pylori Infection and Halitosis – Evidence, Hypothesis, and Korean Red Ginseng to Mitigate Its Effect

Halitosis is a common and ignored condition, but in some, it is a disease-associated health problem, suggestive of overt disease conditions and hasaffected about 25–30% of world’s population, bothering nonmedical social disturbance in many people. Although two kinds, pseudohalitosis and halitophobia, are also concerned, genuine halitosis originated from the oral cavity, such as gingivitis, caries, and poor oral hygiene, in 80% and the remaining 20% are extraoral sources of halitosis, which should not be ignored because of stigmata suggestive of overt tissue dysfunctions, for instance, poor nutrition and hygiene, alcohol abuse, smoking, and systemic illness such as chronic obstructive pulmonary disease, liver cirrhosis, diabetes mellitus, and chronic renal diseases. In this chapter, Helicobacter pylori (H. pylori)–associated halitosis as one of the extragastric manifestations is introduced. Since diagnostics of halitosis includes subjective methods (examiner’s sense of smell) and objective methods (instrumental analysis), under the hypothesis of a possible relationship between H. pylori infection and objective halitosis, the real levels of volatile sulfur compounds (VSCs) in the breath showed significant correlation between VSC levels and the degree of H. pylori–associated erosive gastritis as well as gastric cancer. These findings are further validated through either measuring H2S level in gastric juices of H. pylori–infected gastritis or checking the expressions of cystathionine-γ-lyase (CSE) and cystathionine-β-synthase (CBS) responsible for H2S generation in biopsied stomach. The eradication of H. pylori significantly ameliorated halitosis, accompanied with significant reductions in gastric H2S levels (p<0.01). Korean red ginseng was very effective in either reducing H. pylori–associated H2S or alleviating halitosis in patients with H. pylori–associated chronic atrophic gastritis. Conclusively, H. pylori infection demonstrates to have an important relationship with the development of halitosis, and its eradication could possibly promote the improvement of this condition

Impacts of Heavy Rain and Typhoon on Allergic Disease

AbstractObjectivesAllergic disease may be increased by climate change. Recent reports have shown that typhoon and heavy rain increase allergic disease locally by concentration of airborne allergens of pollen, ozone, and fungus, which are causes of allergic disease. The objective of this study was to determine whether typhoon and heavy rain increase allergic disease in Korea.MethodsThis study included allergic disease patients of the area declared as a special disaster zone due to storms and heavy rains from 2003 to 2009. The study used information from the Korea Meteorological Administration, and from the National Health Insurance Service for allergic diseases (asthma, allergic rhinitis, and atopic dermatitis).ResultsDuring a storm period, the numbers of allergy rhinitis and atopic dermatitis outpatients increased [rate ratio (RR) = 1.191; range, 1.150–1.232] on the sixth lag day. However, the number of asthma outpatients decreased (RR = 0.900; range, 0.862–0.937) on the sixth lag day after a disaster period. During a storm period, the numbers of allergic rhinitis outpatients (RR = 1.075; range, 1.018–1.132) and atopy outpatients increased (RR = 1.134; range, 1.113–1.155) on the seventh lag day. However, the number of asthma outpatients decreased to RR value of 0.968 (range, 0.902–1.035) on the fifth lag day.ConclusionThis study suggests that typhoon and heavy rain increase allergic disease apart from asthma. More study is needed to explain the decrease in asthma

Pathological hypersexuality induced by dopamine replacement therapy in a patient with progressive supranuclear palsy

To the Editor: The pathogenesis of pathological hypersexuality is still in controversy. To our knowledge, this is the first report of pathological hypersexuality induced by two different dopamine receptor agonists in a single patient with progressive supranuclear palsy. In this case, dopamine D2 receptor agonism, perhaps specifically D3 receptor subclass agonism, might have played a key role in the development of pathological hypersexuality induced by dopamine replacement therapy

Deficiency of peroxiredoxin 2 exacerbates angiotensin II-induced abdominal aortic aneurysm

Abdominal aortic aneurysm: Potential enzyme biomarker identified An enzyme with antioxidant properties may provide a biomarker and therapeutic agent to help treat abdominal aortic aneurysm (AAA). AAA involves the structural deterioration of the aorta through chronic inflammation and oxidative stress, and can trigger life-threatening artery rupture. An antioxidant enzyme called peroxiredoxin 2 (PRDX2) is increased in patients with ruptures, but whether its role in AAA is beneficial or detrimental is unclear. Goo Taeg Oh at the Ewha Womans University in Seoul, Jong-Gil Park at the Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea, and co-workers examined the effect of PRDX2 on AAA progression. PRDX2 suppressed structural damage in mice, limiting artery dilation and protein degradation. Loss of PRDX2 accelerated AAA development. Measuring levels of PRDX2 may indicate AAA severity in patients, while boosting the enzyme could repair aortic damage

Early Bile Duct Cancer Detected by Direct Peroral Cholangioscopy with Narrow-Band Imaging after Bile Duct Stone Removal

Cholangioscopy not only enables the direct visualization of the biliary tree, but also allows for forceps biopsy to diagnosis early cholangiocarcinoma. Recently, some reports have suggested the clinical usefulness of direct peroral cholangioscopy (POC) using an ultra-slim endoscope with a standard endoscopic unit by a single operator. Enhanced endoscopy, such as narrow band imaging (NBI), can be helpful for detecting early neoplasia in the gastrointestinal tract and is easily applicable during direct POC. A 63-year-old woman with acute cholangitis had persistent bile duct dilation on the left hepatic duct after common bile duct stone removal and clinical improvement. We performed direct POC with NBI using an ultra-slim upper endoscope to examine the strictured segment. NBI examination showed an irregular surface and polypoid structure with tumor vessels. Target biopsy under direct endoscopic visualization was performed, and adenocarcinoma was documented. The patient underwent an extended left hepatectomy, and the resected specimen showed early bile duct cancer confined to the ductal mucosa