Polyion Hydrogels of Polymeric and Nanofibrous Carboxymethyl Cellulose and Chitosan: Mechanical Characteristics and Potential Use in Environmental Remediation.

Recently, cellulose and other biomass nanofibers (NFs) have been increasingly utilized in the design of sustainable materials for environmental, biomedical, and other applications. However, the past literature lacks a comparison of the macromolecular and nanofibrous states of biopolymers in various materials, and the advantages and limitations of using nanofibers (NF) instead of conventional polymers are poorly understood. To address this question, hydrogels based on interpolyelectrolyte complexes (IPECs) between carboxymethyl cellulose nanofibers (CMCNFs) and chitosan (CS) were prepared by ele+ctrostatic cross-linking and compared with the hydrogels of carboxymethyl cellulose (CMC) and CS biopolymers.

Decadal-centennial-scale solar-linked climate variations and millennial-scale internal oscillations during the Early Cretaceous.

Understanding climate variability and stability under extremely warm 'greenhouse' conditions in the past is essential for future climate predictions. However, information on millennial-scale (and shorter) climate variability during such periods is scarce, owing to a lack of suitable high-resolution, deep-time archives. Here we present a continuous record of decadal- to orbital-scale continental climate variability from annually laminated lacustrine deposits formed during the late Early Cretaceous (123-120 Ma: late Barremian-early Aptian) in southeastern Mongolia.

Comparison of Body Fluid Volumes Determined by Kinetic Modeling and by Bioimpedance Spectroscopy.

Introduction: The bioimpedance spectroscopy (BIS) method is used in individual patients requiring body fluid volume measurement. In a hemodialysis facility, however, regular screening of body fluid volumes is also necessary. Such screening, by kinetic modeling, may become possible by calculating distribution volumes of urea and uric acid from regular blood test results.

Adsorptive Removal of Heavy Metal Ions, Organic Dyes, and Pharmaceuticals by DNA-Chitosan Hydrogels.

DNA-chitosan (DNA-CS) hydrogel was prepared by in situ complexation between oppositely charged DNA and chitosan polyelectrolytes via electrostatic cross-linking to study its adsorption characteristics. The DNA-chitosan hydrogel matrix contains (i) cationic (NH) and anionic (PO) sites for electrostatic binding with ionic species, (ii) -OH and -NH groups and heteroaromatic DNA nucleobases for chelation of heavy metal ions, and (iii) DNA double-helix for recognition and binding to small organic molecules of various structures and polarities. DNA-CS hydrogels efficiently bind with Hg, Pb, Cd, and Cu metal cations of significant environmental concern.

Fluorescent Behavior of Dibenzazepine-containing Polymers in Epoxy Resin.

Dibenzazepine derivatives were added to epoxy resin (bisphenol A diglycidyl ether, DGEBA). DSC analyses showed that DGEBA could be cured by the addition of secondary and tertiary alkylamine-type compounds, but not by the addition of an N-butoxycarbonyl substituted compound. Curing of the cast film and the adhesion of glass substrates by a dibenzazepine-containing polymers/DGEBA mixture was also observed.

Uric acid distribution volume calculated by kinetic modeling and extracellular volume predicted by bioimpedance method.

Background: Several reports indicate that extracellular volume predicted by bioimpedance analysis method is associated with hydration status of hemodialysis patients.

Theory: Fundamentally, uric acid does not cross cell membranes by simple diffusion, either by facilitated diffusion or by active transport. In addition, uric acid cannot move through cell membranes in most tissues other than those involved in uric acid excretion.

Current recovery from sewage wastewater using electrochemically oxidized graphite felt.

The oxidation of a carbon anode has been reported to enhance electricity recovery in a microbial fuel cell (MFC). This study investigates the applicability of electrochemically oxidized graphite felt (EOGF) as the anode for the recovery of electricity from sewage wastewater when polarized at 0.2 V during MFC operation.

Preparation of Dibenzazepine-containing Polymers and Use as Fluorescent Functional Additives for Estimating Plastic Blend.

Dibenzazepine-containing polymers were prepared by various polymerization methods and the effects of adding the obtained polymers to plastics were investigated. Dibenzazepine homopolymers were prepared by the oxidative polymerization of commercially available dibenzazepine derivatives and by the dehalogenative polymerization of corresponding dibromodibenzazepines. Dibenzazepine copolymers were prepared from dibromodibenzazepines.

Omniphobic Metal Surfaces with Low Contact Angle Hysteresis and Tilt Angles.

Various metal (Al, Ti, Fe, Ni, and Cu) surfaces with native oxide layers were rendered "omniphobic" by a simple thermal treatment of neat liquid trimethylsiloxy-terminated polymethylhydrosiloxanes (PMHSs) with a range of different molecular weights (MWs). Because of this treatment, the PMHS chains were covalently attached to the oxidized metal surfaces, giving 2-10 nm thick PMHS layers. The resulting surfaces were fairly smooth, liquid-like, and showed excellent dynamic omniphobicity with both low contact angle hysteresis (≲5°) and substrate tilt angles (≲8°) toward small-volume liquid drops (5 μL) with surface tensions ranging from 20.

Electricity Recovery from Municipal Sewage Wastewater Using a Hydrogel Complex Composed of Microbially Reduced Graphene Oxide and Sludge.

Graphene oxide (GO) has recently been shown to be an excellent anode substrate for exoelectrogens. This study demonstrates the applicability of GO in recovering electricity from sewage wastewater. Anaerobic incubation of sludge with GO formed a hydrogel complex that embeds microbial cells via π-π stacking of microbially reduced GO.

Estimation of the Compatibility of Blend Composites of Resins by Measuring the Fluorescent Spectra.

The effects of adding desipramine-containing fluorescence polymer (poly(10,11-dihydro-5-[3-(N-methylamino)propyl]dibenz[b,f]azepine-2,8-diyl-alt-9,9-didodecylfluorene-2,7-diyl, PAzep-Fl) to resins were investigated. When composites were prepared by a reactive blend of poly(lactic acid) (PLA), PAzep-Fl, and diisocyanate, the molecular weight of the obtained composite was larger than that of the composite, which was blended without PAzep-Fl; this suggested that chemical bonding occured between PLA and PAzep-Fl via diisocyanate. The effects of adding PAzep-Fl in two kinds of resins/lysine triisocyanate (LTI) blend were also investigated.

Graphene oxide-dependent growth and self-aggregation into a hydrogel complex of exoelectrogenic bacteria.

Graphene oxide (GO) is reduced by certain exoelectrogenic bacteria, but its effects on bacterial growth and metabolism are a controversial issue. This study aimed to determine whether GO functions as the terminal electron acceptor to allow specific growth of and electricity production by exoelectrogenic bacteria. Cultivation of environmental samples with GO and acetate as the sole substrate could specifically enrich exoelectrogenic bacteria with Geobacter species predominating (51-68% of the total populations).

Immobilization and Photocurrent Activity of a Light-Harvesting Antenna Complex II, LHCII, Isolated from a Plant on Electrodes.

A light-harvesting (LH) antenna complex II, LHCII, isolated from spinach was immobilized onto an indium tin oxide (ITO) electrode with dot patterning of 3-aminopropyltriethoxysilane (APS) by utilizing electrostatic interactions between the cationic surface of the electrode and the anionic surface of stromal side of the LHCII polypeptide. Interestingly, the illumination of LHCII assembled onto the ITO electrode produced a photocurrent response that depends on the wavelength of the excitation light. Further, LHCII was immobilized onto a TiO nanostructured film to extend for the development of a dye-sensitized biosolar cell system.

Synthesis of Thiophene- and Bithiophene-Based Alternating Copolymers via Pd-Catalyzed Direct C-H Arylation.

Polycondensation via direct C-H arylation of thiophene derivatives gave thiophene- and bithiophene-based alternating copolymers in good yields. The optimization of the reaction conditions was investigated in terms of a catalytic system and reaction time. Under optimized conditions, the polycondensation reaction of 3,3',4,4'-tetramethylbithiophene with 2,7-dibromo-9,9-dioctylfluorene gave poly[2,7-(9,9-dioctylfluorene)--5,5'-(3,3',4,4'-tetramethyl-2,2'-bithiophene)] with a molecular weight of 31 800 in 91% yield.

Flexible host frameworks with diverse cavities in inclusion crystals of bile acids and their derivatives.

We have systematically investigated structures and properties of inclusion crystals of bile acids and their derivatives. These steroidal compounds form diverse host frameworks having zero-, one- and two-dimensional cavities, causing various inclusion behaviors towards many organic compounds. The diverse host frameworks exhibit the following guest-dependent flexibility.

Estimation of dietary nutritional content using an online system with ability to assess the dieticians' accuracy.

We developed an online system for estimating dietary nutritional content. It also had the function of assessing the accuracy of the participating dieticians and ranking their performance. People who wished to have their meal estimated (i.

Construction of superhydrophobic surfaces by fibrous aggregation of perfluoroalkyl chain-containing organogelators.

Superhydrophobic surfaces, characterized by water contact angles greater than 150 degrees, can be produced by means of intermediate organogels, which were formed by perfluoroalkyl chain-containing organogelators with volatile organic solvents.

Separation of plastic mixtures using liquid-fluidized bed technology.

Separation of heavier-than-water plastic mixtures had been investigated via the fluidization of their packed beds induced by an upward flow of water. The samples examined were resin pellets and crushed plastic products including PVC, PET and PBT. On the onset of a flow, a mixed bed was swelled to the state of fluidization and separated into layers of respective resins depending on their density.

Hydrometallurgical recovery of zinc from ashes of automobile tire wastes.

Study has been performed on the investigation of metal leaching behavior for fly and bottom ashes from automobile tire wastes using acid and alkaline solutions from both viewpoints of environmental protection and resource utilization. The two ashes were found to contain substantial amounts of zinc and iron along with small quantities of cobalt, manganese, magnesium, copper, titanium and aluminum. The fly ash contained a much larger amount of zinc than the bottom ash, and seems to be a promising secondary source for the metal.

Near-IR absorption and fluorescence spectra and AFM observation of the light-harvesting 1 complex on a mica substrate refolded from the subunit light-harvesting 1 complexes of photosynthetic bacteria Rhodospirillum rubrum.

The subunit light-harvesting 1 (LH 1) complexes isolated from photosynthetic bacteria Rhodospirillum rubrum using n-octyl-beta-glucoside were reassociated and adsorbed on a mica substrate using spin-coat methods with the aim of using this LH complex in a nanodevice. The near-IR absorption and fluorescence spectra of the LH 1 complexes indicated that the LH 1 complex on the mica was stable, and efficient energy transfer from a carotenoid to a bacteriochlorophyll a was observed. Atomic force microscopy of the reassociated LH 1 complexes, under air, showed the expected ringlike structure.

Organic intercalation material: reversible change in interlayer distances by guest release and insertion in sandwich-type inclusion crystals of cholic acid.

Cholic acid (CA) forms inclusion crystals that have a sandwich-type lamellar structure constructed by the alternative stacking of host bilayers and guest layers. Five disubstituted benzenes, o-toluidine, m-fluoroaniline, o-chlorotoluene, o-bromotoluene, and indene, are accommodated in the two-dimensional void space between the host bilayers at 1:2 host-guest stoichiometries. Thermal gravimetric analysis of the inclusion crystals revealed that all the guest molecules, except o-toluidine, are released in two separate steps, indicating the formation of intermediate crystals after the first guest release.

Decolorization and degradation of xanthene dyes by a white rot fungus, Coriolus versicolor.

The decolorization of six xanthene dyes (conc. 100 microM) by a white rot fungus, Coriolus versicolor (C. versicolor), was investigated in liquid culture.