All-Optical WDM Buffer System Realized by NOLM and Feedback Loop Structure

We propose an all-optical WDM buffer for optical packet switching system, which consists of NOLM and feedback loop. The proposed structure provides more than 40 turn buffering and nice output of buffered data when selected by control signal.     

Bandwidth Allocation Method by Service for WDM EPON

A WDM(Wavelength Division Multiplexing) EPON(Ethernet Passive Optical Network) is an economical and efficient access network that has attracted significant research attention in recent years. A MAC(Media Access Control) Protocol of PON is based on TDMA(Time Division Multiple Access) basically, we can classify this protocol into a fixed length slot assignment method suitable for leased line supporting Qos(Quality of Service) and a variable length slot assignment method suitable for LAN/MAN with the best efforts. In this paper, we present bandwidth allocation method by service for WDM EPON and verify this method by simulation results.     

Eco-friendly decoration of graphene oxide with green synthesized silver nanoparticles: cytotoxic activity

Research on Chemical Intermediates - The aim of the present study was to focus on the green synthesis of silver nanoparticles (AgNPs) using the aqueous extract of dried jujube fruit and the...     

Differential Regulation of Human Serotonin Receptor Type 3A by Chanoclavine and Ergonovine

Irritable bowel syndrome (IBS) is a chronic disease that causes abdominal pain and an imbalance of defecation patterns due to gastrointestinal dysfunction. The cause of IBS remains unclear, but intestinal-brain axis problems and neurotransmitters have been suggested as factors. In this study, chanoclavine, which has a ring structure similar to 5-hydroxytryptamine (5-HT), showed an interaction with the 5-HT_3A receptor to regulate IBS. Although its derivatives are known to be involved in neurotransmitter receptors, the molecular physiological mechanism of the interaction between chanoclavine and the 5-HT_3A receptor is unknown. Electrophysiological experiments were conducted using a two-electrode voltage-clamp analysis to observe the inhibitory effects of chanoclavine on Xenopus oocytes in which the h5-HT_3A receptor was expressed. The co-application of chanoclavine and 5-HT resulted in concentration-dependent, reversible, voltage-independent, and competitive inhibition. The 5-HT_3A response induced by 5-HT was blocked by chanoclavine with half-maximal inhibitory response concentration (IC₅₀) values of 107.2 µM. Docking studies suggested that chanoclavine was positioned close F130 and N138 in the 5-HT_3A receptor-binding site. The double mutation of F130A and N138A significantly attenuated the interaction of chanoclavine compared to a single mutation or the wild type. These data suggest that F130 and N138 are important sites for ligand binding and activity. Chanoclavine and ergonovine have different effects. Asparagine, the 130th amino acid sequence of the 5-HT_3A receptor, and phenylalanine, the 138th, are important in the role of binding chanoclavine, but ergonovine has no interaction with any amino acid sequence of the 5-HT_3A receptor. The results of the electrophysiological studies and of in silico simulation showed that chanoclavine has the potential to inhibit the hypergastric stimulation of the gut by inhibiting the stimulation of signal transduction through 5-HT_3A receptor stimulation. These findings suggest chanoclavine as a potential antiemetic agent for excessive gut stimulation and offer insight into the mechanisms of 5-HT_3A receptor inhibition.     

Simultaneous determination of benzene,toluene, ethylbenzene,and xylene metabolites in human urine using electromembrane extraction combined with liquid chromatography and tandem mass spectrometry

For the first time, electromembrane extraction combined with liquid chromatography and tandem mass spectrometry was applied for the determination of urinary benzene, toluene, ethylbenzene, and xylene metabolites. S‐Phenylmercapturic acid, hippuric acid, phenylglyoxylic acid, and methylhippuric acid isomers were extracted from human urine through a supported liquid membrane consisting of 1‐octanol into an alkaline acceptor solution filling the inside of a hollow fiber by application of an electric field. Various extraction factors were investigated and optimized using response surface methodology, the statistical method. The optimum conditions were established to be 300 V applied voltage, 15 min extraction time, 1500 rpm stirring speed, and 5 mM ammonium acetate (pH 10.2) acceptor solution. The method was validated with respect to selectivity, linearity, accuracy, precision, limit of detection, limit of quantification, recovery, and reproducibility. The results showed good linearity (r² > 0.995), precision, and accuracy. The extract recoveries were 52.8–79.0%. Finally, we applied this method to real samples and successfully measured benzene, toluene, ethylbenzene, and xylene metabolites.     

Isoflavone Changes in Immature and Mature Soybeans by Thermal Processing

The isoflavone changes occurring in mature soybeans during food processing have been well studied, but less information is available on the changes in immature soybeans during thermal processing. This study aimed to determine the effect of thermal processing by dry- or wet-heating on the changes in the isoflavone profiles of immature and mature soybeans. In the malonylglycoside forms of isoflavone, their deglycosylation was more severe after wet-heating than after dry-heating regardless of the soybean maturity. The malonyl forms of isoflavones in the immature seeds were drastically degraded after a short wet-heating process. In the acetylglycoside forms of isoflavone, dry-heating produced relatively low amounts of the acetyl types in the immature soybeans compared with those in the mature soybeans. These results were explained by the content of acetyldaidzin being relatively less changed after dry-heating immature soybeans but increasing four to five times in the mature soybeans. More of the other types of acetylglycoside were produced by dry-heating soybeans regardless of their maturity. Acetylgenistin in wet-heating was a key molecule because its content was unchanged in the immature soybeans during processing but increased in the mature soybeans. This determined the total acetylglycoside content after wet-heating. In contrast, most of the acetyl forms of isoflavone were produced after 90 to 120 min of dry-heating regardless of the seed maturity. It can be suggested that the pattern of isoflavone conversion was significantly affected by the innate water content of the seeds, with a lower water content in the mature soybeans leading to the greater production of acetyl isoflavones regardless of the processing method even if only applied for a relatively short time. The results suggested that the isoflavone conversion in the immature soybeans mainly follows the wet-heating process and can be promoted in the application of stronger processing.     

Correlation of the Rates of Solvolysis of the Benzhydryldimethylsulfonium Ion. Application of the Aromatic Ring Parameter(1)

Values for the specific rates of solvolysis of the benzhydryldimethylsulfonium ion in 34 solvents have been analyzed using various forms of the extended Grunwald-Winstein equation. The specific rates are insensitive toward changes in solvent nucleophilicity (N(T)) values, and they correlate best against a combination of Y(+) values (based on the solvolyses of the 1-adamantyldimethylsulfonium ion) and aromatic ring parameter (I) values. Common-molecule return is observed, being especially powerful in solvents rich in fluoro alcohol; the logarithm of the associated mass law constant correlates inversely with the solvent N(T) values. The product selectivities in ethanol-water mixtures are also consistent with an S(N)1 mechanism for the solvolyses.