Ferromagnetic properties of (Ga,Mn)N nanowires grown by a chemical vapor deposition method

Ferromagnetic (Ga,Mn)N nanowires were grown on sapphire substrates at 900 degrees C by a chemical vapor deposition. Synchrotron radiation photoemission spectroscopy revealed that no secondary phases were found in the grown nanowire, meaning the dissolution of Mn atoms to form a solid solution in GaN nanowire. Fermi level was apart by 3.0,eV in the GaN nanowire (n-type), and it shifted toward the valance band maximum with ammonia flow rate. The Ga-to-N ratio decreased with the increase of ammonia flow rate, leading to the increase of Ga vacancies. From this, it is suggested that both increases in magnetic moment and Curie temperature with ammonia flow rate originated from the solid solution of Mn and Ga vacancies.open4

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

Anti-inflammatory effects of isoketocharbroic acid from brown alga, Sargassum micracanthum

During our on-going screening program designed to isolate natural compounds from marine environments, we isolated isoketochabrolic acid (IKCA) from Sargassum micracanthum, an important brown algae distributed in Jeju Island, Korea. Furthermore, we evaluated the inhibitory effects of IKCA on nitric oxide (NO) production in lipopolysaccharide (LPS)-triggered macrophages. IKCA strongly inhibited NO production, with an IC50 value of 58.31 μM. Subsequent studies demonstrated that IKCA potently and concentration-dependently reduced prostaglandin E2 (PGE2), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 cytokine production. In conclusion, to the best of our knowledge, this is the first study to show that IKCA isolated from S. micracanthum has a potent anti-inflammatory activity. Therefore, IKCA might be useful as an anti-inflammatory health supplement or functional cosmetics

Comparison of Posterior Lumbar Interbody Fusion and Posterolateral Lumbar Fusion in Monosegmental Vacuum Phenomenon within an Intervertebral Disc

Study DesignRetrospective.PurposeTo compare the clinical and radiological outcomes of posterolateral lumbar interbody fusion (PLIF) and posterolateral lumbar fusion (PLF) in monosegmental vacuum phenomenon within an intervertebral disc.Overview of LiteratureThe vacuum phenomenon within an intervertebral disc is a serious form of degenerative disease that destabilizes the intervertebral body. Outcomes of PLIF and PLF in monosegmental vacuum phenomenon are unclear.MethodsMonosegmental instrumented PLIF and PLF was performed on 84 degenerative lumbar disease patients with monosegmental vacuum phenomenon (PLIF, n=38; PLF, n=46). Minimum follow-up was 24 months. Clinical outcomes of leg and back pain were assessed using visual analogue scales for leg pain (LVAS) and back pain (BVAS), and the Oswestry disability index (ODI). The radiographic outcome was the estimated bony union rate.ResultsLVAS, BVAS, and ODI improved in both groups. There was no significant difference in the degree of these improvements between PLIF and PLF patients (p>0.05). Radiological union rate was 91.1% in PLIF group and 89.4% in PLF group at postoperative 24 months (p>0.05).ConclusionsNo significant differences in clinical results and union rates were found between PLIF and PLF patients. Selection of the operation technique will reflect the surgeon's preferences and patient condition

Rhodium-oxide-coated indium tin oxide for enhancement of hole injection in organic light emitting diodes

The authors report the enhancement of hole injection using an RhOx layer between indium tin oxide anodes and 4, 4??? -bis[N-(1-naphtyl)- N -phenyl-amino]biphenyl in organic light-emitting diodes (OLEDs). The operation voltage of OLEDs at 700 cdm2 decreased from 13 to 10 V as the Rh layer changed to RhOx by surface treatment using O2 plasma. Synchrotron radiation photoelectron spectroscopy results showed that the work function increased by 0.2 eV as the Rh layer transformed into RhOx. Thus, the hole injection energy barrier was lowered, reducing the turn-on voltage and increasing the quantum efficiency of OLEDs.open281

Short range scattering effect of InAs quantum dots in the transport properties of two dimensional electron gas

Short range interaction between two dimensional electron gas (2DEG) and InAs quantum dots embedded in the GaAs/AlGaAs quantum well is investigated as a function of carrier density. At low carrier density the interaction is significantly characterized by a transport to quantum lifetime ratio of less than 5. However, with an increase in carrier density, quantum lifetime is observed to undergo a sharp transition from 0.17 to 0.25 ps. This is attributed to the screening of short range repulsive scattering due to InAs quantum dots by the 2DEG.open7

Dispersion retrieval from multi-level ultra-deep reactive-ion-etched microstructures for terahertz slow-wave circuits

A multi-level microstructure is proposed for terahertz slow-wave circuits, with dispersion relation retrieved by scattering parameter measurements. The measured return loss shows strong resonances above the cutoff with negligible phase shifts compared with finite element analysis. Splitting the circuit into multi levels enables a low aspect ratio configuration that alleviates the loading effect of deep-reactive-ion etching on silicon wafers. This makes it easier to achieve flat-etched bottom and smooth sidewall profiles. The dispersion retrieved from the measurement, therefore, corresponds well to the theoretical estimation. The result provides a straightforward way to the precise determination of dispersions in terahertz vacuum electronics.</jats:p

Cytoprotective Effect of Phloroglucinol on Oxidative Stress Induced Cell Damage via Catalase Activation

Abstract We investigated the cytoprotective effect of phloroglucinol, which was isolated from Ecklonia cava (brown alga), against oxidative stress induced cell damage in Chinese hamster lung fibroblast (V79-4) cells. Phloroglucinol was found to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydrogen peroxide (H 2 O 2 ), hydroxy radical, intracellular reactive oxygen species (ROS), and thus prevented lipid peroxidation. As a result, phloroglucinol reduced H 2 O 2 induced apoptotic cells formation in V79-4 cells. In addition, phloroglucinol inhibited cell damage induced by serum starvation and radiation through scavenging ROS. Phloroglucinol increased the catalase activity and its protein expression. In addition, catalase inhibitor abolished the protective effect of phloroglucinol from H 2 O 2 induced cell damage. Furthermore, phloroglucinol increased phosphorylation of extracellular signal regulated kinase (ERK). Taken together, the results suggest that phloroglucinol protects V79-4 cells against oxidative damage by enhancing the cellular catalase activity and modulating ERK signal pathway