Localized surface acetylation of aqueous counter collision cellulose nanofibrils using a Pickering emulsion as an interfacial reaction platform.

The self-organization of nano-sized fibrous building blocks is essential for the construction of biomimetic architectonics and hierarchically constructed bio-based materials. The localization of hydrophobic moieties on the surfaces of such nanofibrils is key to hierarchical assembly in aqueous systems. In this study, unique self-assembling fibrous building blocks comprising amphiphilic cellulose nanofibrils (CNFs) were prepared by aqueous counter collision (ACC). The purpose of the study was to control the surface properties of ACC-CNFs by selectively acetylating their surfaces at the oil/water interfaces of a Pickering emulsion. Localized interfacial reactions occurred when the ACC-CNFs were adsorbed onto the surfaces of oil droplets containing the reaction reagents. Such acetylation reactions were achieved whilst maintaining the crystallinity and fibrous morphology of the original CNFs. The surfaces of films cast from the acetylated ACC-CNFs described herein had unique self-aggregation properties that contrasted markedly with those of films cast from acetylated ACC-CNFs prepared in homogenous dispersions.

Characterization of an Amphiphilic Janus-Type Surface in the Cellulose Nanofibril Prepared by Aqueous Counter Collision.

Cellulose nanofibrils, which attract extensive attention as a bio-based, sustainable, high-performance nanofibril, are believed to be predominantly hydrophilic. This study aimed to prove the presence of an amphiphilic "Janus-type fiber surface" in water with hydrophobic and hydrophilic faces in a cellulose nanofibril (ACC-CNF) that was prepared by the aqueous counter collision method. We clarified the surface characteristics of the ACC-CNF by confocal laser scanning microscopy with a carbohydrate-binding module and congo red probes for the hydrophobic planes on the cellulose fiber surfaces and calcofluor white as hydrophilic plane probes. The results indicated the presence of both characteristic planes on a single ACC-CNF surface, which verifies an amphiphilic Janus-type structure. Both hydrophobic probes adsorbed onto ACC-CNFs for the quantitative evaluation of the degree of ACC-CNF surface hydrophobicity by Langmuir's adsorption theory based on the optimal maximum adsorption amounts for various starting raw material types.

Facile surface modification of amphiphilic cellulose nanofibrils prepared by aqueous counter collision.

The present study concerns the chemical modification of the surfaces of cellulose nanofibrils (CNFs) prepared by aqueous counter collision (ACC). Wood-derived CNFs prepared by ACC were acetylated with acetic anhydride in an aqueous dispersion. The moderately acetylated nanofibrils were more readily dispersible in water than unmodified CNFs, although the original nanofibrous morphology comprising crystalline cellulose I remained almost unchanged. This indicates that the surfaces of the crystalline CNFs had been selectively acetylated, which possibly inhibited self-aggregation between the nanofibrils, thereby facilitating dispersion in the aqueous medium. Despite the absence of additives, the acetylated CNFs were readily adsorbed onto hydrophobic surfaces, and retained their compatibility with water, which improved their ability to stabilize emulsions and coat plastic resin particles in water. The results indicate that the amphiphilic properties of CNFs prepared by ACC can be controlled by this facile surface acetylation method, which potentially increases their usefulness in various fields.

A defective prostaglandin E synthase could affect egg formation in the silkworm Bombyx mori.

We had previously reported a prostaglandin E synthase (bmPGES) in the silkworm Bombyx mori that catalyzes the isomerization of PGH2 to PGE2. The present study aimed to provide a genome-editing characterization of bmPGES in B. mori. Results showed bmPGES gene disruption to result in a reduced content of PGE2. The change affected the expression of chorion genes and egg formation in silkworms. Collectively, the results indicated that bmPGES could be involved in reproduction of B. mori. Therefore, this study provides insights into the physiological role of bmPGES and PGE2 in silkworms.

Pickering emulsion stabilization by using amphiphilic cellulose nanofibrils prepared by aqueous counter collision.

Cellulose nanofibrils prepared by aqueous counter collision (ACC-nanocelluloses) have specific properties. In this study, the use of ACC-nanocelluloses as emulsifiers and stabilizers was investigated. Oil-in-water Pickering emulsions with long-term stabilities were easily prepared by ultrasonically mixing aqueous ACC-nanocellulose dispersions with non-polar solvents. Stable Pickering emulsions were obtained because the emulsification abilities of the ACC-nanocelluloses were significantly higher than those of cellulose nanofibrils prepared by high-pressure homogenization or other chemical preparation methods. This might be due to exposure of inherently hydrophobic surface planes of cellulose nanofibrils by ACC. The emulsification and stability of the Pickering emulsions were sensitive to the solvent properties such as permittivity, density and viscosity.

One-step synthesis of cellooligomer-conjugated gold nanoparticles in a water-in-oil emulsion system and their application in biological sensing.

Monodisperse gold nanoparticles (GNPs) were synthesized in a water-in-oil emulsion system (reverse micelles) composed of 80% N-methylmorpholine N-oxide (NMMO)/20% H2O and dodecane, stabilized with an anionic surfactant: bis(2-ethylhexyl)sulfosuccinate sodium salt. Cellooligomers with a degree of polymerization of 6 or 15 (ßGlc6 or ßGlc15, respectively), which were labeled at each reducing end group with thiosemicarbazide (TSC) and dissolved in the aqueous NMMO phase, were successfully conjugated to the surfaces of GNPs in situ during spontaneous NMMO-mediated gold reduction. As-synthesized ßGlc6-GNPs and ßGlc15-GNPs had average diameters of 11.3 ± 2.1 and 10.5 ± 0.7 nm, respectively, while their surface sugar densities were 0.21 and 0.51 chains nm-2, respectively. Concanavalin A (ConA), a lectin that recognizes non-reducing end groups of glucose residues, aggregated with ßGlc15-GNPs with higher sensitivity than it did with ßGlc6-GNPs, possibly as a result of the sugar density on the GNP surfaces. The aggregates were rapidly re-suspended by adding methyl-ß-d-glucopyranoside as a binding inhibitor. Other lectins and proteins showed no interaction with ßGlc-GNPs. Therefore, clustering of glucose non-reducing ends on the GNP surfaces via strong intermolecular association of cellooligomers, possibly led to high affinity for ConA. This facile synthesis route to structural carbohydrate-decorated GNPs has potential applications in carbohydrate-nanometal conjugate nano-biosensor development.

Comparative Analysis of the WISC between Two ADHD Subgroups.

OBJECTIVE: The prevalence of attention deficit/hyperactivity disorder (ADHD) in school-age children is 7.2%, and ADHD is divided into clinical subtypes. METHODS: The current study explored whether specific cognitive profiles as assessed using the Wechsler Intelligence Scale for Children (WISC)-IV could be obtained for each clinical ADHD subtype (ADHD-Inattentive type and ADHD-Combined type) and investigated the correlation between WISC scores and parental age at their children's birth or birthweight. The enrolled sample comprised 12 ADHD-I and 15 ADHD-C subjects. RESULTS: An impaired Processing Speed Index was found in ADHD-I. The age of the father at the child's birth and birthweight positively correlated with the full scale intelligence quotient (FSIQ) score in the WISC assessment. CONCLUSION: Inattentiveness within the behaviors of the children with ADHD-I is partly due to the impaired processing speed, therefore effective support for ADHD will be conducted if educator decreases their speaking speed. Since biological basis of ADHD is still largely unknown, future studies using both psychological and biological methods will reveal the etiology of ADHD. These scientific assessments will provide information for more effective approaches in the care of children with ADHD.

Formulation and Composition Effects in Phase Transitions of Emulsions Costabilized by Cellulose Nanofibrils and an Ionic Surfactant.

Cellulose nanofibrils (CNF) offer great prospects as a natural stabilizer of colloidal dispersions and complex fluids for application in food, pharma, and cosmetics. In this study, an ionic surfactant (sodium dodecyl sulfate, SDS) was used as emulsifier of oil-in-water and water-in-oil emulsions that were further costabilized by addition of CNF. The adsorption properties of SDS in both, CNF dispersions and emulsions, as well as the influence of composition (CNF and SDS concentration) and formulation (ionic strength, oil, and CNF types) on the phase behavior were elucidated and described in the framework of Windsor systems. At low salinity, the phase transition of emulsions containing CNF and SDS at low concentrations was controlled by molecular transfer in the oil-in-water system. Irregular droplets and "bi-continuous" morphologies were observed at medium and high salinity for systems containing high CNF and SDS concentrations. Water-in-oil emulsions were only possible at high salinity and SDS concentrations in the presence of small amounts of CNF. The results revealed some subtle differences in CNF interfacial activity, depending on the method used for their isolation via fiber deconstruction, either from microfluidization or aqueous counter collision. Overall, we propose that the control of emulsion morphology and stability by addition of CNF opens the possibility of developing environmentally friendly complex systems that display high stability and respond to ionic strength following the expectations of classical emulsion systems.

Comparative analysis of autistic traits and behavioral disorders in Prader-Willi syndrome and Asperger disorder.

Prader-Willi syndrome (PWS) is a neuro-genetic disorder caused by the absence/loss of expression of one or more paternally expressed genes on chromosome 15 (q11-13). In this study, a comparative analysis of intelligence level and autistic traits was conducted between children with PWS (n = 30; 18 males, 12 females; age = 10.6 ± 2.8 years) and those with Asperger disorder (AD; n = 31; 24 males, 7 females; age = 10.5 ± 3.1 years). The children were compared by age group: lower elementary school age (6-8 years), upper elementary school age (9-12 years), and middle school age (13-15 years). As results, the intelligence levels of children with PWS were significantly lower than those with AD across all age groups. Autistic traits, assessed using the Pervasive Developmental Disorders Autism Society Japan Rating Scale (PARS), revealed that among elementary school age children, those with PWS had less prominent autistic traits than those with AD, however, among middle school age children, those with PWS and AD showed similar prominence. An analysis of the PARS subscale scores by age group showed that while the profiles of autistic traits for children with PWS differed from those of children with AD at elementary school age, the profiles showed no significant differences between the groups at middle school age. The findings suggest that autistic traits in PWS become gradually more prominent with increasing of age and that these autistic traits differ in their fundamental nature from those observed in AD.

Preparation of lactose-modified cellulose films by a nonaqueous enzymatic reaction and their biofunctional characteristics as a scaffold for cell culture.

Enzymatic glyco-modification of transparent cellulose films with lactose was achieved by nonaqueous biocatalysis, and rat hepatocyte attachment behavior to the lactose-modified cellulose films was investigated. Regenerated cellulose films were incubated with lactose using a surfactant-enveloped cellulase in lithium chloride/dimethylacetamide solvent at 37 degrees C for 24 h, and lactose molecules were successfully introduced to the cellulose films. The initial cell adhesion on the lactose-modified cellulose films was superior to the original cellulose film. In the absence of serum, hepatocytes were significantly attached only on the lactose-modified cellulose films. This process was markedly suppressed by the addition of free lactose as an inhibitor. These results suggest that such cell adhesion proceeded through a direct interaction between galactose residues on the cellulose films and asialoglycoprotein receptors on the rat liver cell surface. This novel approach for surface glyco-modification of a cellulose matrix and its biofunctional properties are expected to provide potential application as a bioactive scaffold for cell culture engineering.

Morphological imaging of single methylcellulose chains and their thermoresponsive assembly on a highly oriented pyrolytic graphite surface.

Individual methylcellulose (MC) chains and their thermoresponsive assembly were successfully visualized on a highly oriented pyrolytic graphite (HOPG) surface by atomic force microscopy (AFM). Momentary contact of a dilute MC solution at 4 degrees C onto the HOPG substrate permitted clear imaging of individual MC chains having a molecular thickness of ca. 0.5 nm and a hexagonal orientation. By increasing the solution temperature from 4 to 80 degrees C, it was possible to bring about significant changes in the MC nanomorphology from stretched molecular chains to disordered massive aggregates. It was presumed that the hydrophobic interaction between the MC chains and the HOPG pi-conjugated system led to the successful visualization of thermally responsive changes in the MC conformations. These results imply that HOPG substrates could be used for clear nanoimaging of cellulosic polymers and other structural polysaccharides.

Molecular imaging of single cellulose chains aligned on a highly oriented pyrolytic graphite surface.

Individual cellulose macromolecules were successfully visualized on a highly oriented pyrolytic graphite (HOPG) surface by tapping-mode atomic force microscopy under ambient condition. Monomolecular-level dispersion of cellulose chains was achieved through the momentary contact of dilute cellulose/cupri-ethylenediamine (Cu-ED) solution onto the HOPG substrate. Both concentrations of cellulose and Cu-ED provided critical impacts on the topographical images. Single cellulose chains with molecular height of ca. 0.55 nm could be observed under the optimal conditions, showing rigid molecular rods with a unique morphology of hexagonal regularity. It was strongly suggested that the cellulose chains were aligned along the HOPG crystal lattice through a specific attraction, possibly due to a CH-pi interaction between the axial plane of cellulose and the HOPG pi-conjugated system. These phenomena would imply the potential applications of an HOPG substrate for not only nano-level imaging, but also for molecular alignment of cellulose and other structural polysaccharides.

Conformational changes in single carboxymethylcellulose chains on a highly oriented pyrolytic graphite surface under different salt conditions.

Conformational changes in individual carboxymethylcellulose (CMC) chains deposited on a highly oriented pyrolytic graphite (HOPG) surface were investigated by atomic force microscopy (AFM). A small amount of CMC solution with various salt concentrations was deposited onto the HOPG surface. The CMC molecular chains adsorbed onto the HOPG surface were clearly visualized using tapping-mode AFM under ambient conditions, as compared with those on a hydrophilic mica surface. Each CMC chain was distinguishable at the molecular level based on the vertical profiles of the AFM images, and probably aligned along the HOPG crystal lattice. Higher NaCl concentrations brought about dramatic conformational changes from aligned single chains to globular aggregates via the molecular network structure only on the HOPG surface through electrostatic screening of the CM groups. Although CMC is a water-soluble hydrophilic polyelectrolyte, some interaction, possibly due to a CH-pi bonding between the glucopyranosic axial plane of CMC and the aromatic rings of HOPG, is considered to be effective and dominant for the unique molecular attachment. These phenomena would imply the potential use of HOPG as a substrate for not only molecular imaging, but also for nano-scale morphological control of cellulosic polymers and other structural polysaccharides.