Aquatic environmental monitoring of detergent surfactants

Since 1998, Japan Soap and Detergent Association has been continuously evaluating the concentrations of four surfactants used in household detergents and fabric conditioners in river surface water: linear alkylbenzene sulfonate (LAS), polyoxyethylene alkyl ether (AE), alkyldimethylamine oxide (AO) and dialkyl dimethylammonium chloride (DADMAC) in Japanese urban rivers, in order to assess the risks of surfactants on aquatic organisms. Surfactant concentrations in the river water in June and September were found to be lower than those in March and December, the season where water temperature is lower, suggesting that the rates of biodegradation in environmental water differ depending on the water temperature. All the measured surfactant concentrations were below the reported predicted no-effect concentration (PNEC) and have been decreasing year by year; suggesting that surfactant risk on aquatic organisms in Japanese rivers is low under current conditions.     

Oxidative coupling polymerization of octahydroxyquaternaphthyl derivatives producing stereocontrolled polybinaphthol

Summary The oxidative coupling polymerization of the novel quaternaphthyl monomers, such as (S,S,S)-3,3”’-dihydroxy-2,2’,3’,2”,3”2”’-hexamethoxy-1,1’:4’,1”:4”,1”’-quarter-naphthyl and (S,S,S)-3’,2”-dibenzyloxy-3,3”’-dihydroxy-2,2’,3”2”’-tetramethoxy-1,1’:4’,1”:4”,1”’-quaternaphthyl, with the copper(I) chloride-(S)-2,2’-isopropyridene-bis(4-phenyl-2-oxazoline) catalyst was performed. The obtained polybinaphthol derivatives consisted of about 20 repeating naphthalene units and the stereochemical composition of up to an 88% enantiomer excess (S).     

Synthesis and gelation of novel fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide copolymers containing triol segments—Interaction of these fluorinated gels with various hydrophilic compounds

Fluoroalkyl end‐capped N‐(1,1‐dimethyl‐3‐oxobutyl)acrylamide (DOBAA) copolymers containing triol segments were prepared by the reactions of fluoroalkanoyl peroxide with the corresponding monomer and N‐tris(hydroxymethyl)methylacrylamide (NAT). These obtained fluorinated copolymers [R_F‐(DOBAA)_x‐(NAT)_y‐R_F] were found to cause gelation in water, dimethyl sulfoxide, and N,N‐dimethylformamide under the non‐crosslinked conditions, although the corresponding nonfluorinated DOBAA–NAT copolymer [‐(DOBAA)_x‐(NAT)_y‐] could cause no gelation in these solvents. This gelation is governed by the synergistic interaction of strong aggregations of end‐capped fluoroalkyl segments and intermolecular hydrogen bonding between triol segments. We also studied the uptake and release of a variety of hydrophilic compounds such as methylene blue, methyl orange, 4‐hydroxyazobenzene‐4′‐sulfonic acid sodium salt, 2,4‐dihydroxyazobenzene‐4′‐sulfonic acid sodium salt, acriflavine hydrochloride, acridine hydrochloride, lucigenin, and fluorescein by this fluorinated copolymer gel and fluoroalkyl end‐capped NAT homopolymer gel [R_F‐(NAT)_n‐RF] for comparison. It was demonstrated that the uptake and release ratios of these hydrophilic compounds by R_F‐(DOBAA)_x‐(NAT)_y‐R_F gel become generally lower than those of R_F‐(NAT)_n‐R_F gel. Interestingly, R_F‐(DOBAA)_x‐(NAT)_y‐R_F gel has no releasing power toward methylene blue, acridine hydrochloride, lucigenin, and fluorescein, although R_F‐(NAT)_n‐R_F gel has a good releasing power toward these compounds. Additionally, R_F‐(DOBAA)_x‐(NAT)_y‐R_F gel was applied to the controlled release of anticancer drugs such as methotrexate (MTX), and the releasing ratios of MTX became higher with increasing pH values (from pH 4.3 to 9.1). © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88:3212–3217, 2003     

Aberrant expression of glycosylation in juvenile gastrointestinal stromal tumors

Most adult gastrointestinal stromal tumors (GIST) are thought to be caused by activating mutations in the KIT or PDGFRA gene. However, many juvenile GIST lack either mutation and are considered to develop with a different pathogenesis. To investigate the molecular characteristics of juvenile GIST, we analyzed the proteome difference in phosphorylated protein between adult and juvenile GIST. Eleven GIST samples (seven adult cases and four juvenile cases lacking either mutation) were analyzed by using immunostaining and LC-MS/MS. Comparative analysis of tyrosine-phosphorylated protein levels showed that juvenile GIST possessed phosphorylated KIT in spite of lacking mutation in the KIT gene. Moreover, downstream signals of KIT were also activated as in adult GIST. Although, SDS-PAGE gels showed that there was a difference of each KIT bands between adult and juvenile GIST, they became the same after removal of N-glycans or sialic acids. Moreover, one of the most typical enzymes, ST6Gal1, which transfers Neu5Ac residues in α2-6 linkage to Gal β1-4GlcNAc units on N-glycans, is significantly less expressed in juvenile GIST. This suggests that the difference in KIT is generated by post-translational modification and may play a role in the progression of juvenile GIST.     

Wet‐Route Synthesis and Characterization of Yb:CaF2 Optical Ceramics

This paper reports a new strainless fabrication method for ytterbium‐doped CaF₂ laser ceramics involving no drying step before green body casting. The nanoparticles were kept in aqueous solution until green body shaping. Centrifugation was used to obtain correct compactness of the green body before sintering. Characterizations were conducted at different steps of the fabrication process. No grain boundaries oxidation was observed in the sintered ceramics although the nanoparticles were permanently maintained in water until they were sintered. Finally, these ceramics are more homogeneous and have less light scattering defects (no porosity), and present improved optical properties when compared to ceramics obtained from dried nanopowders.     

Proteomics application of crops in the context of climatic changes

Abiotic stress caused by global climate change varies widely, which negatively affect crops growth and productivity throughout the world. Environmental changes can alter plant’s physiological state and trigger several signaling pathways for adaptation to unfavorable conditions. Plant response to abiotic stress includes changes in protein expression and post-translational modification of proteins to activate their defense system against the challenges. Research on plant proteomes has provided beneficial information for a comprehensive understanding of the protein networks in plants in response to external stimuli. Large-scale proteomics is a powerful approach for studies of complex biological processes in which a number of proteins take part; proteome analysis of sub-cellular structures and modified proteins has enabled identification of novel components of plant stress responses that had not previously been discovered. In this review, we have discussed the recent developments of crop proteomics in the context of several climatic factors including photosynthetic stress, air pollutants, thermal stress including heat and cold, and osmotic stress, including drought, salt, and flooding stress, and metal stress. The aim of this review is to take a snapshot of several proteomic approaches in crop plants that provide a comprehensive list of components affected by certain abiotic stresses in climate. The biological relevance of these proteins in regard to plant stress tolerance will be described as well.     

Homologue and isomer distribution of dioxins observed in water samples collected from Kahokugata Lagoon and inflowing rivers, Japan

Water samples were collected at 17 sites in Kahokugata Water Basin, a closed water basin in central Japan. We determined the concentration of dioxins of the water samples. Linear relationships between toxic equivalent (TEQ) concentrations of dioxin and concentrations of suspended solid (SS) were obtained at sites in Kahokugata Lagoon and in the rivers flowing into the lagoon. Homologue composition of polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) indicated that all the water samples were still strongly influenced by chlorinated herbicides, such as chloronitrofen (CNP) and pentachlorophenol (PCP) that had been widely used in rice fields. The main isomer distributions of the PCDD homologues were not significantly different among the sampling sites, while the main isomer distributions of the PCDF homologues were considerably different among the sampling sites. At a few sampling points in the downstream part of one of the rivers, high concentrations of 1,3,6,7,8-pentachloro dibenzofuran (1,3,6,7,8-PeCDF) and its related isomers (1,3,6,8-chlorine-substituted PCDFs) were traced to a dye manufacturing plant. These non-toxic isomers are usually only minor constituents in environmental water samples and are not indicators of any known dioxin sources. The dyeing discharge was found to make a contribution only in the water samples collected near the plant and the seasonal variation of the contribution might depend on the flow rate of the river.