Chemiresistive and resistive switching semiconductor based sensor for biomolecule detection

Recently, chemiresistive semiconductor, which varies its resistance or conductance status based on chemical phenomena at its surface, has been developed as a sensor device for biomolecule detection. Particularly, graphene has been one of the best example for the chemiresistive semiconductors, even for resistive switching semiconductors. In addition, the graphene is two-dimensional (2D) carbon structure having a large surface area, where significant biosensing applications have been continuously reported. In this study, we demonstrated reduced graphene oxide (rGO) biosensor structure for a stress hormone, i.e. cortisol, sensing. The device structure was stepwise self-assembly monolayers (SAMs) stacked by reduced graphene oxide between source and drain. Then, cortisol monoclonal antibody (c-Mab) was chemically tethered on reduced graphene oxide layer for the cortisol detection by its specific antigen-antibody binding. The current versus voltage (I-V) curve exhibited resistance changes and resistive switching I-V behaviors as a sensing mechanism, which demonstrated a unique possibility of rGO semiconductor based sensor. Also, chemiresistance change in the forms of resistance ratio was calibrated in terms of sensing cortisol concentration as shown in Figure 1. Please click Additional Files below to see the full abstract

Calorimetric Measurements of Magnetic-Field-Induced Inhomogeneous Superconductivity Above The Paramagnetic Limit

We report the first magneto-caloric and calorimetric observations of a magnetic-field-induced phase transition within a superconducting state to the long-sought exotic "FFLO" superconducting state first predicted over 50 years ago. Through the combination of bulk thermodynamic calorimetric and magnetocaloric measurements in the organic superconductor $\kappa$ - (BEDT-TTF)$_2$Cu(NCS)$_2$, as a function of temperature, magnetic field strength, and magnetic field orientation, we establish for the first time that this field-induced first-order phase transition at the paramagnetic limit $H_p$ for traditional superconductivity is to a higher entropy superconducting phase uniquely characteristic of the FFLO state. We also establish that this high-field superconducting state displays the bulk paramagnetic ordering of spin domains required of the FFLO state. These results rule out the alternate possibility of spin-density wave (SDW) ordering in the high field superconducting phase. The phase diagram determined from our measurements --- including the observation of a phase transition into the FFLO phase at $H_p$ --- is in good agreement with recent NMR results and our own earlier tunnel-diode magnetic penetration depth experiments, but is in disagreement with the only previous calorimetric report.Comment: 5 pages, 5 figure

Circulating levels of DNA-histone complex and dsDNA are independent prognostic factors of disseminated intravascular coagulation

AbstractIntroductionNeutrophils can be induced to release DNA combined with histones. The resulting neutrophil extracellular trap (NET) provides a scaffold for growing hemostatic plug. Therefore, the NET formation may be inevitable in clinical conditions that are characterized by formation of vascular thrombi. Thus far, there have been no reports on the clinical significance of NET in disseminated intravascular coagulation (DIC). Therefore, we investigated circulating levels of NET in DIC and analyzed their potential values to assess coagulation severity and predict clinical outcome.MethodsThe plasma levels of DNA-histone complexes and double-stranded DNA (dsDNA), considered to be in vivo markers of NET, were measured in 199 patients suspected of having DIC and 20 healthy controls.ResultThe circulating levels of DNA-histone complexes and dsDNA were significantly elevated in overt-DIC. The increased levels of these two markers correlated with the severity of coagulopathy including DIC score and D-dimer. Multivariable Cox regression analysis, adjusted for the conventional DIC markers, revealed that elevated DNA-histone complexes and dsDNA are poor independent prognostic markers.ConclusionThe circulating levels of NET release reflect the coagulation activation and adverse clinical outcomes in patients with DIC, thereby providing potential clinical relevance for mortality prediction in DIC

Tetramethyl-O-scutellarin isolated from peels of immature Shiranuhi fruit exhibits anti-inflammatory effects on LPSinduced RAW264.7 cells

Purpose: To investigate the anti-inflammatory activity of the ethanol extract of the immature fruit of a citrus, Shiranuhi, and to identify the active ingredient.Methods: The immature Shiranuhi peel was extracted with 80 % ethanol, and the extract was fractionated with solvents (n-hexane, ethyl acetate and n-butanol) to afford the corresponding fractions and water residue. Among them, the EtOAc-soluble portion was subjected to medium pressure liquid chromatography (MPLC) over a reversed-phase SiO2 column to give compound 1. The isolated compound was identified based on the proton and carbon nuclear magnetic resonance (NMR) spectra. The release of nitric oxide, prostaglandin (PG)E2, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 secreted by mouse macrophages was measured using RAW264.7 cell culture supernatant.Results: Shiranuhi (Korean name, Hallabong) is an important citrus species cultivated in Jeju Island, Korea. A polymethoxyflavonoid (PMF), tetramethyl-O-scutellarin (1), was isolated from the peels of immature Shiranuhi fruit. Upon the evaluation of anti-inflammatory effects, the flavonoid 1 decreased the nitric oxide production in macrophage cells with high efficiency, viz, 50 % inhibition concentration, IC50 of 57.4 μM. Subsequent studies demonstrated that PMF 1 effectively inhibited the generation of PGE2, TNF-α, IL-1β, and IL-6 cytokine in a dose-dependent manner.Conclusion: Tetramethyl-O-scutellarin (1) has been successfully isolated from Shiranuhi species for the first time. Thus, Shiranuhi fruit peel extract containing PMF 1 can potentially be applied as an antiinflammatory ingredient in food or cosmetic industries.Keywords: Shiranuhi fruit, Nitric oxide, Tetramethyl-O-scutellarin, Anti-inflammator

Improvement of the Usability of Online Mentoring Website

The purpose of this study is to improve the usability of the current online mentoring website by deriving what should be improved through assessment and reflecting it to system improvement. The related data such as search log and Think Aloud were collected from user groups (9 users in total), and usability was tested according to the predefined test procedures. The collected data were analyzed, using quantitative methods. In terms of search log, the related items including effectiveness, efficiency, satisfaction and error were quantified according to usability testing standards. Then, descriptive statistics was performed. According to usability comparison before and after system improvement, it has mostly improved such as improved effectiveness (increase by 15 points), better efficiency (reduction by 41 seconds), increase in satisfaction (by 8 points) and decrease in error frequency (decrease by 1.2 times). Usability testing should be viewed as a process, not outcome itself. Therefore, it could be used during system prototype in addition to the current system and useful in system improvement