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.     

Characterization of Single Particles in Urban Atmospheric Aerosols Over Nagoya Based on Mass Spectral Analysis

Mass spectral analysis of single aerosol particles was performed using a high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) in the urban area of Nagoya, Japan, for five days in the autumn of 2010. An ion-series analysis was applied to the single-particle mass spectra; the sum of the masses at Δ of 1, 3, 4, and 5 divided by the total mass of organics (f_Δ1,3-5) was used as an indicator of the degree of oxygenation of the organics. The organic mass fraction (F_org) and f_Δ1,3-5 of single particles varied substantially, and the results for the entire period indicate that two groups of particles with high and low f_Δ1,3-5 were present. The organics in particles with high F_org were less oxygenated, whereas those with low F_org were more oxygenated; these different particles were associated with hydrocarbon-like organic aerosols (HOA) and low-volatility oxygenated organic aerosols (LV-OOA), respectively, based on the PMF analysis of the MS mode data. The size distributions of the two types of particles overlapped substantially. The degree of the overlap depends on the equivalent particle diameter used, indicating the importance of single-particle analysis in understanding the size-composition relationship in detail. Alteration of the aerosol mixing state was clearly indicated by the changes in f_Δ1,3-5 and F_org; the homogeneous conditions changed to externally mixed conditions from the evening until noon of the next day. Possible causes of this alteration include the condensation of oxygenated organics and ammonium nitrate onto pre-existing particles. This study demonstrated the usefulness of single-particle analysis based on electron-ionization aerosol mass spectrometry.

Copyright 2015 American Association for Aerosol Research     

Rho-associated kinase-dependent contraction of stress fibres and the organization of focal adhesions

Stress fibres and associated focal adhesions in cells constitute a contractile apparatus that regulates cell motility and contraction. Rho-kinase, an effector molecule of small GTPases, regulates non-muscle cell motility and contractility. Rho-kinase mediates the contraction of stress fibres in a Ca²⁺-independent manner, and is responsible for slower and more finely tuned contraction of stress fibres than that regulated by myosin light chain kinase activity in living cells. The specific inhibition of the Rho-kinase activity causes cells to not only lose their stress fibres and focal adhesions, but also to appear to lose their cytoplasmic tension. Activated Rho-kinase is also involved in the organization of newly formed stress fibres and focal adhesions in living cells.     

Functional properties and chemical composition of fractionated brown and yellow linseed meal (Linum usitatissimum L.)

Considering its high content of protein and dietary fiber, linseed meal is a remarkable source for food ingredient and food additive production. In this study, brown and yellow linseed meal (Linum usitatissimum L.) were fractionated via pH control, to obtain five linseed meal fractions rich in protein and fiber. The fractions were characterized by measuring functional properties, proximate and carbohydrate composition, and lignan contents. Acid soluble protein fractions were characterized by lower emulsification capacities and foaming activities in comparison to a commercial soy protein isolate. Alkaline soluble protein fractions showed emulsification activities comparable to whole egg and relatively high contents of secoisolariciresinol diglucoside (SDG) of 110 mg/g DM and 56.2 mg/g DM, respectively. The good emulsification and foaming activities, as well as the enriched concentration of SDG and therefore high nutritional value, make especially the alkaline soluble protein fraction highly interesting for food ingredient production.     

Synthesis and properties of novel poly(tetramethylsilnaphthylenesiloxane) derivatives

Novel poly(tetramethylsilnaphthylenesiloxane) derivatives were synthesized and characterized by differential scanning calorimetry (DSC), thermogravimetry (TG), and X-ray diffraction analyses. Poly(tetramethylsilnaphthylenesiloxane) derivatives were obtained by condensation polymerization of the corresponding disilanol derivatives, i.e. 1,4-, 1,5-, 2,6-, and 2,7-bis(dimethylhydroxysilyl)naphthalenes, which were prepared by the Grignard reaction using chlorodimethylsilane and the corresponding dibromonaphthalene derivatives followed by the hydrolyses, catalyzed by palladium on charcoal. The obtained poly(tetramethyl-1,5-silnaphthylenesiloxane) was insoluble in common organic solvents; however, the other polymers exhibited the good solubility in common organic solvents, such as tetrahydrofuran (THF), chloroform, dichloromethane, and toluene. The introduction of tetramethyl-1,5-silnaphthylenesiloxane units into the resulting polymer was confirmed by ¹H NMR spectrum of the copolymer obtained by condensation copolymerization of 1,5-bis(dimethylhydroxysilyl)naphthalene with 1,4-bis(dimethylhydroxysilyl)naphthalene. It was revealed from the DSC and X-ray diffraction measurements that poly(tetramethyl-1,5-silnaphthylenesiloxane) and poly(tetramethyl-2,6-silnaphthylenesiloxane) exhibited the crystallinity; however, poly(tetramethyl-1,4-silnaphthylenesiloxane) and poly(tetramethyl-2,7-silnaphthylenesiloxane) were amorphous. The glass transition temperature (T_g) and the temperature at 5% weight loss (T_d5) of poly(tetramethylsilnaphthylenesiloxane) derivatives with dimethylsilyl group at 1-position of the naphthylene moiety were higher than those at 2-position of the naphthylene moiety. The T_g and melting point (T_m) of the present polymers were higher than those of poly(tetramethyl-1,4-silphenylenesiloxane).     

Stabilization of liposomal membranes by carotenoids: Zeaxanthin,zeaxanthin glucoside and thermozeaxanthin

We investigated the membrane-stabilizing effect of three synthesized polar carotenoids, thermozeaxanthin (TZ), zeaxanthin glucoside (ZG) and zeaxanthin (Z), using the fluorescent calcein-leakage measurement from the calcein-entrapped liposomes composed of dipalmitoylphosphatidylcholine (DPPC). The addition of TZ stabilized the liposomal membranes composed of DPPC at pH values ranging from 4.0 to 10.0. The addition of three carotenoids, TZ, ZG and Z, stabilized the membrane at acidic and neutral pH values ranging from 4.0 to 7.5. The values of leakage were lower at 30 °C and highest at 40 °C, and subsequently, gradually decreased at the higher temperature. The addition of TZ and Z stabilized the membranes, whereas, ZG destabilized the membranes at a temperature higher than 50 °C. In addition, the membrane-stabilizing effect of the carotenoids with the calcein-entrapped liposomes composed of lipids extracted from Thermus thermophilus were investigated. The addition of TZ resulted in stabilization of the membrane at all ranges of pH values. However, the addition of Z and ZG destabilized the membrane.     

Durability of electrochromic glazing

Fundamental properties of all-solid-state electrochromic windows to control the solar energy have been investigated. This system comprises of multilayer represented as Glass/ITO/NiO/Inorganic Electrolyte (Ta₂O₅, etc.)/ WO₃/ITO/ Adhesive Film/ Glass. Of the various electrochromic systems examined so far, the most important features are their environmental stability and the possibility of large area applications. Our system can control the visible transmittance between 72.6% and 17.6% and has a cyclic life over 100000 cycles at 60°C. Based on the accelerated weathering tests, the stability of the system is estimated to be over five years for outdoor applications. For the problem of scaling up, some technical aspect is given and the prototype window of size 40×60 cm is exemplified. The present system could be more suitable for architectural and automobile applications in the near future by developing production technology.     

Identification of the protein import components of the rat mitochondrial inner membrane, rTIM17, rTIM23, and rTIM44

A large number of pharmaceutically active compounds have a high affinity to acidic phospholipids; good examples are the cationic compounds lidocaine, propranolol, and gentamycin. These drugs influenced the lipid dynamics of liposomes composed of phosphatidylcholine and the acidic phosphatidylglycerol, as judged by the excimer/monomer emission intensity ratio for a pyrene-labeled phospholipid analog, as well as by polarization of DPH fluorescence. When the mole fraction X of PG (XPG) was 0.20, lidocaine increased membrane fluidity. The opposite was true for propranolol, which caused the formation of pyrene lipid-enriched microdomains. Gentamycin had no apparent effect. At XPG = 1.00, all these drugs rigidified membrane. Subsequently, we investigated the detachment of a cationic peripheral membrane protein, cytochrome c (cyt c), by these compounds from liposomes. This was accomplished by monitoring resonance energy transfer from a pyrene-labeled phospholipid to the heme of cyt c. The efficiency of the above compounds to dissociate cyt c varied considerably. In brief, significantly lower concentrations of gentamycin than propranolol or lidocaine were required for half-maximal dissociation of cyt c from liposomes, although the final extent of protein detachment by gentamycin was less complete. ATP augmented the dissociation of cyt c from membranes by lidocaine and propranolol. Stopped-flow measurements also revealed that the half-times differed for the release of cyt c from the membranes. Our results are likely to reflect differences in the contributions of the electrostatic interactions and hydrophobicity to the drug/lipid interaction and comply with two different acidic phospholipid binding sites in cyt c.     

Rudimentary meningocele of the scalp

A rudimentary meningocele, a variant of primary cutaneous meningioma, was seen on the scalp of a 9-month-old Japanese boy. Clinically, the lesion on the left parietal area was round, about 1.6 cm in diameter, alopecic, and slightly elevated. Histologically, the lesion, located from the dermis to the subcutis, consisted of scattered foci of meningothelial cells, an anastomosing network of empty spaces with psammoma bodies and collagen bodies, and small vessels. Immunohistochemically, the meningothelial cells were positive for vimentin and desmin. Ultrastructurally, they had elongated cytoplasmic processes, intermediate filaments in the cytoplasm, and desmosomal junctions.