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Boroxines, (R-BO)3, which can be easily synthesized via a dehydration reaction of boronic acids, R–B(OH)2, selectively self-assemble in toluene into nanofibers, nanorods, nanotapes, and nanotubes, depending on the aromatic substituent (R). Spectroscopic measurements show that the nanotube consists of a J-aggregate of the boroxine. Humidification converts the morphology from the nanotube to a sheet as a result of the hydrolysis of the boroxine components and subsequent molecular-packing rearrangement from the J-aggregate to an H-aggregate. Such a transformation leads to the compulsive release of guest molecules encapsulated in the hollow cylinder of the nanotube. The hydrolysis and the molecular-packing rearrangement described above are suppressed by coordination of pyridine to the boron atom, with the resulting moiety acting as a Lewis acid of the boroxine component. The pyridine-coordinated nanotube is transformed into a helical coil by humidification. Guest release during the nanotube-to-helical-coil transformation is much slower than during the nanotube-to-sheet transformation, but faster than from a nanotube that did not undergo morphological transformation. The storage and release of guest molecules from the boroxine nanotubes can be precisely controlled by adjusting the moisture level and the concentration of Lewis bases, such as amines.

Amphiphilic monomers, which were quantitatively synthesized from a dehydration reaction between a glycolipid and naphthalene-boronic acids, self-assembled in organic solvents to selectively form tape-like structures (nanotape) and tubular structures (nanotube) depending on the bond position of the boron atom in the naphthalene ring. The nanotube has a strong narrow fluorescence band attributable to the monomer species of the naphthalene group, whereas the nanotape has a weak broad fluorescence band at a relative longer wavelength region based on the excimer species of the naphthalene group. Light energy adsorbed by the naphthalene groups densely and regularly organized in the bilayer membrane wall of the nanotube was transferred, with high quantum efficiency, into anthracene as an acceptor encapsulated in the nanochannel. The supramolecular nanotube proved to be able to act as a light-harvesting antenna.

A pair of 8-shaped poly(tetrahydrofuran)s, poly(THF)s, having a metathesis-cleavable olefinic unit of isomeric forms at the focal position, IIa and IIb, has been synthesized through an electrostatic self-assembly and covalent fixation (ESA-CF) process using a telechelic poly(THF) having N-phenylpyrrolidinium salt groups carrying a tetracarboxylate counteranion containing a trans-3-hexenyl group, as equilibrated isomeric forms of Ia and Ib. The subsequent metathesis cleavage reaction of the olefinic group in IIa and IIb has been conducted with a second generation Grubbs catalyst in the presence of ethyl vinyl ether. The polymer topology was thus converted from a dicyclic 8-shape into two simple loops having the two distinctive sizes consisting of one and two prepolymer units, IIIa and IIIb, respectively, corresponding to the linking mode of the two prepolymer segments on the pair of carboxylate groups at either the neighboring or the remote sites of the tetracarboxylate. Moreover, MALDI−TOF mass analysis h...

Thecooperativeelectrostaticandhydrogen-bondingself-assemblyofpolymerprecursorsand the subsequent covalent conversion have been demonstrated as an effective means for the synthesis of polymer catenanes. Thus, a cyclic poly(tetrahydrofuran), poly(THF), having ahydrogen-bonding, isophtha- loylbenzylic amide group (I) was prepared through an electrostatic self-assembly and covalent fixation with a telechelic poly(THF) having N-phenylpyrrolidinium salt groups carrying a dicarboxylate counteranion containing the hydrogen-bonding unit (1). Another telechelic poly(THF) having an isophthaloylbenzylic amide group at the center position and having N-phenylpyrrolidinium salt end groups carrying a biphenyl- dicarboxylate counteranion,2, was subsequentlypreparedand subjected toacovalent conversionreactionin the presence of the preformed cyclic poly(THF) having a hydrogen-bonding unit (I). A polymer (2)catenane comprised of the two different cyclic poly(THF) components, I and II (from 2), has been isolated up to 7% yield as an acetone-insoluble fraction and unequivocally characterized by means of MALDI TOF mass spectroscopy together with 1 H NMR and SEC techniques.

The molecular packing and self-assembled morphologies of asymmetric bolaamphiphiles, N-(2-aminoethyl)-N'-(β-d-glucopyranosyl)alkanediamide [1(n), n = 12, 14, 16, 17, 18, and 20], were precisely controlled by association/dissociation with poly(thiopheneboronic acid) (PTB). Differential scanning calorimetry, X-ray diffraction, and infrared spectroscopy revealed that the starting film of 1(n) associated with 1 equiv of the boronic acid moiety of PTB, (Film-1(n)PTB), had antiparallel molecular packing of 1(n) moiety within the monolayer membranes. However, the molecular packing of the starting film that contained 0.5 equiv of the boronic acid moiety of PTB (Film-2eq1(n)PTB) was parallel. The dispersion of Film-1(n)PTB in water gave only nanotapes, whereas that of Film-2eq1(n)PTB in water selectively formed nanotubes, through a dissociation reaction of PTB based on the hydrolysis of the boronate esters in the complexes. The nanotapes and nanotubes memorized the antiparallel and parallel molecular packing of the starting films, respectively. Changes in the length of the oligomethylene spacer of 1(n) never affected the molecular packing or self-assembled morphologies. However, the inner diameters of the nanotubes increased irregularly in the range of 67.9-79.6 nm as the length of the oligomethylene spacer of 1(n) increased from n = 12 to n = 18.

A high sensitive analytical method for salmon calcitonin (sCT) was established by means of derivatization with a fluorescence labelling agent, DBD-F, followed by HPLC separation and fluorescence detection at 558 nm with excitation at 430 nm. Under optimized conditions (DBD-F, 0.1 M borate buffer (pH 8.5): acetonitrile (70:30, v/v)), three molecules of DBD-F reacted with one sCT molecule in the presence of 1 mM sodium dodecyl sulphate (SDS) at 50 oC for 3 h. The detection limit for the sCT derivative was 20 fmol. A linear relationship was obtained between the amount of sCT on column and the peak heights in the range of 35–8000 fmol.

Recently a new procedure for measuring serum TSH receptor (TSHR) autoantibody (TRAb) was reported by Smith et al. in which the autoantibodies inhibit binding of a human monoclonal thyroid stimulating antibody M22 (labeled with biotin) to TSHR-coated ELISA plate wells (pTRAb(3rd) assay). The aim of this study was to compare the performance of pTRAb(3rd) assay with pTRAb(2nd) assay based on inhibition of TSH-biotin binding to TSHR-coated ELISA plate wells. In addition, we evaluated the applicability of TRAb3rd assay to discriminate between untreated Graves' disease (GD) and painless thyroiditis (PT). Analysis of sera from 230 healthy controls indicated that only 1 (0.43%) gave inhibition of M22-binding values of greater than 15% (32.8% inhibition). To define the clinical cut-off point for a positive serum with autoantibodies to the TSHR, we performed receiver operating characteristic curve of the data from 244 untreated GD and three different control groups for pTRAb(3rd) assay. With a sensitivity of 99.6% at a cut-off of 14.5%, 22.0% and 22.0% inhibition of M22 binding, the specificity of healthy controls without PT, with PT and with PT excluding postpartum PT and PT during remission of GD was 99.6%, 96.6% and 97.5%, respectively. The pTRAb(3rd) assay was closely correlated to pTRAb(2nd) assay in the 244 untreated Graves' sera (r = 0.911). The pTRAb(3rd) assay detected 243 of 244 (99.6%) untreated GD, whereas 9.2% of PT and 6.7% of the subacute thyroiditis (SAT) were detectable. In contrast, pTRAb (2nd) assay detected 242 of 244 (99.2%) Graves' same sera, while 16.8 % from PT's same sera and 13.3% from SAT were detectable. In conclusion, pTRAb(3rd) assay has significantly (p = 0.0026) superior diagnostic accuracy for GD and PT, compared to that of pTRAb(2nd) assay.

The study was to evaluate the marginal leakage of wet or dry dentin condition after restoration on short-term. In the study we used Photobond adhesive system and Single Bond adhesive system. The specimens were prepared from premolars. A class V cavity was prepared at the CEJ with a high-speed hand piece and #010 round diamond point. The cavity's walls and floors were etched with phosphoric acids of the test materials by wet and dry bonding techniques. The specimens were cross-sectioned longitudinally through the center of the cavities with a low speed diamond micro-cutter and polished with carbide paper (#600-1200) after storage in distilled water for 1 day, and silver nitrate staining. Specimens were viewed with EPMA for elemental distribution of calcium, nitrogen and silver on the resin-dentin interface. The uptake of silver particles was less in samples treated with the wet-bonding technique when compared with dry-bonding technique. This in vitro study showed that bonding technique is important in establishing a seal along the restoration margins to control marginal leakage.

In situ carbon coating was carried out with a glow discharge in methane-hydrogen mixtures on the wall of the JIPP T-IIU tokamak at room temperature. The concentration of hydrogen and deuterium in C-films was analyzed by thermal desorption spectroscopy (TDS) and elastic recoil detection analysis (ERDA). Good agreement was obtained between results deduced from these two methods. Hydrogen concentration is 40–55 at. % in the C-films. Replacement of H in the C-layer was tried using a pure D2 glow discharge. In order to achieve complete replacement, a fluence of 2 × 1017 cm−2 was needed at room temperature. The replacement process was monitored by a quadrupole mass analyzer and results are compared with Hα/Dα observation of tokamak discharges and the results of the surface analysis.

The effectiveness of the in-situ carbon coating (carbonization) has been demonstrated to reduce the radiation loss by iron impurities during ICRF heating in the JIPP T-IIU tokamak. As a result of carbonization, the total radiation loss decreased down to one fifth of the RF power, which resulted in an increase in electrons and total stored energy compared with these conditions before carbonization. The thickness of the carbon layer was 300–900 A, and its toroidal uniformity was within a factor of 3, although only one anode and one gas-inlet were used. A thin carbide layer is formed between the C-film and the stainless steel substrate with carbonization at room temperature. The hydrogen concentration is 40–50 at.% in the carbon layer. Deposition of carbon was observed on window materials. The deposition rate was relatively less on electrical insulators compared to the deposition rate on metals.