Modeling of asymmetric giant magnetoimpedance in amorphous ribbons with a surface crystalline layer

A model describing the asymmetric giant magnetoimpedance (GMI) in field-annealed amorphous ribbons is proposed. It is assumed that the ribbon consists of an inner amorphous core and surface hard magnetic crystalline layers. The model is based on a simultaneous solution of linearizied Maxwell equations and Landau-Lifshitz equation. The coupling between the surface layers and the amorphous core is described in terms of an effective bias field. Analytical expressions for the frequency and field dependences of the ribbon impedance are found. The calculated dependences are in a qualitative agreement with results of experimental studies of the high-frequency asymmetric giant GMI in field-annealed amorphous ribbons.Comment: 13 pages, 3 figure

ANTIPROLIFERATION EFFECTS OF SELECTED TANZANIA PLANTS

Background: Plants still remain a prime source of drugs for the treatment of cancer and can provide leads for the development of novel anticancer agents. Our screening of indigenous medicinal plants from Tanzania has led to the identification of the number of anticancer activity. Material and methods: The current study investigates the cytotoxic activity of methanol extracts of one hundred and thirty seven Tanzania plants used locally for the traditional medicine herb using the MTS assay on the HepG2 cell lines. Result 16% of the tested plant extracts showed moderate to strong inhibitory activity with IC50 values ranging from 17.1 ± 1.1 μg/ml to 79.2 ± 0.7 μg/ml ; meanwhile, ten extracts (7.3%) could demonstrate cytotoxic activity with IC50 values less than 27.6 ± 2.0 μg/ml; twelve extracts (8.8%) could demonstrate cytotoxic activity with IC50 values ranging from 30.4 ± 1.6 μg/ml to 79.2 ± 0.7μg/ml. Conclusion : Especially, a methanol extract from the bark extract of Erythrophleum zimmermannii (Fabaceae) was found to be the most cytotoxicity against HepG2 cell lines (IC50 = 17.1 ± 1.1 μg/ml)

Airborne Measurements of High Pollutant Concentration Events in the Free Troposphere over the West Coast of South Korea between 1997 and 2011

Aircrafts enable the direct measurement of chemical components in the free troposphere (FT). This study employed airborne measurements to examine the occurrences of high concentrations of SO2 and NOx in the FT over the coastal region west of the Seoul metropolitan area, South Korea. The data from a long-term (1997-2011) airborne measurement campaign were used to determine the meteorological conditions favorable for carrying these pollutants into the Seoul area. The back trajectory analyses of 21 instances of high FT pollutant concentration events showed ascending patterns from the major pollutant sources, mainly the industrial complexes in eastern China, in 9 instances and passing patterns in 12 instances. In the ascending instances, developing low-pressure systems over the source regions provide favorable conditions to uplift air pollutants from the surface into the FT. In the passing instances, an anomalous low-pressure system near the surface prevented airflows from descending into the boundary layer and upper-level anticyclonic systems helped to keep the ascending airflows in the FT. This study proposes the basic mechanisms for predicting air quality in the Seoul area, considering that air pollutants in the FT often entrain into the boundary layer to increase local concentrationsopen0

Human dopamine receptor nanovesicles for gate-potential modulators in high-performance field-effect transistor biosensors

The development of molecular detection that allows rapid responses with high sensitivity and selectivity remains challenging. Herein, we demonstrate the strategy of novel bio-nanotechnology to successfully fabricate high-performance dopamine (DA) biosensor using DA Receptor-containing uniform-particle-shaped Nanovesicles-immobilized Carboxylated poly(3,4-ethylenedioxythiophene) (CPEDOT) NTs (DRNCNs). DA molecules are commonly associated with serious diseases, such as Parkinson's and Alzheimer's diseases. For the first time, nanovesicles containing a human DA receptor D1 (hDRD1) were successfully constructed from HEK-293 cells, stably expressing hDRD1. The nanovesicles containing hDRD1 as gate-potential modulator on the conducting polymer (CP) nanomaterial transistors provided high-performance responses to DA molecule owing to their uniform, monodispersive morphologies and outstanding discrimination ability. Specifically, the DRNCNs were integrated into a liquid-ion gated field-effect transistor (FET) system via immobilization and attachment processes, leading to high sensitivity and excellent selectivity toward DA in liquid state. Unprecedentedly, the minimum detectable level (MDL) from the field-induced DA responses was as low as 10 pM in real- time, which is 10 times more sensitive than that of previously reported CP based-DA biosensors. Moreover, the FET-type DRNCN biosensor had a rapid response time (<1 s) and showed excellent selectivity in human serum

The Roots of Atractylodes macrocephala

The root of Atractylodes macrocephala Koidzumi (Atractylodis Rhizoma Alba, ARA) is a Traditional Korean Medicine and has been commonly used for weight control. Mitochondrial dysfunction appears to be a key contributor to insulin resistance, and therefore mitochondrial targeting drugs represent an important potential strategy for the treatment of insulin resistance and obesity. In this study, the authors investigated the regulatory effects of ARA on mitochondrial function with respect to the stimulation of glucose and lipid metabolism in C2C12 myotubes. After differentiating C2C12 myotubes, cells were treated with or without different concentrations (0.2, 0.5, and 1.0 mg/mL) of ARA extract. ARA extract significantly increased the expression of peroxisome proliferator-activated receptor coactivator 1 alpha (PGC1α) and the downregulations of its targets, nuclear respiratory factor-1 (NRF-1), transcription factor A (TFAM), and total ATP content in C2C12 myotubes. ARA extract also increased the expressions of PGC1α activator and of the metabolic sensors, AMP-activated protein kinase (AMPK), and acetyl-CoA carboxylase and sirtuin (SIRT) 1. Furthermore, it significantly increased glucose uptake by enhancing glucose consumption and subsequently decreased FFA contents and increased carnitine palmitoyltransferase (CPT) 1b expression. Our study indicates that ARA has a potential for stimulating mitochondrial function and energy metabolism in muscle