Preparation of a biodegradable superabsorbent polymer and measurements of changes in absorption properties depending on the type of surface‐crosslinker

A superabsorbent polymer (SAP) is a special polymer material that can absorb up to 500 times its own weight of pure water, but has a problem that it does not biodegrade itself and cause environmental pollution. Therefore, we aim to prepare a biodegradable SAP by using biomass‐based IA. The SAP must be able to retain absorbed water and absorb water under a given pressure. We have carried out studies to improve the surface hardness of the SAP to enhance absorption of water under a given pressure by surface‐crosslinking. Four types of surface‐crosslinkers, ethylene glycol diglycidyl ether (EGDGE), ethylene carbonate (EC), 1,4‐butanediol (BD), or glycerol, were used. We confirmed the water absorption capacity of the SAP by measuring its centrifuge retention capacity (CRC) and absorbency under load (AUL). The structural characteristics of the SAP were confirmed by attenuated total reflection (ATR) and X‐ray photoelectron spectroscopy (XPS), and the surface characteristics were confirmed by scanning electron microscopy (SEM).     

Canonical labels for protein spots of proteomics maps

We consider the problem of canonical labeling for a class of maps, which include proteomics maps, which consist of a set of vertices or protein spots. If this problem is solved and followed, different laboratories studying proteomics maps will arrive at the same numbering of spots, which would facilitate comparisons of data from different sources. In addition, the proposed canonical numberings of protein spots would allow compiling a catalog of proteomics maps just as canonical labeling allows making catalogs graphs, or molecules, and other canonically labeled systems, which would make search for similar sets of maps very efficient. We approach the problem by modifying the algorithm of Jeffrey for graphical representation of DNA based on the chaos game. Graphical representation of DNA as a chaos game map has an important property in that this representation allows one to assign sequential labels to spots in a DNA map. We have modified the approach for sequential labeling of chaos game map representations to graphical representation of any tabular data, such as listing of (x, y) coordinates of protein spots of proteomics maps.     

Efficient Synthesis of Biologically Active (±)‐Confluentin and (±)‐Daurichromenic Acid

One‐step synthesis of biologically active (±)‐confluentin is described from commercially available orcinol with trans,trans‐farnesal in the presence of ethylenediamine diacetate as a catalyst. Further conversion of synthetic confluentin to highly potent anti‐HIV agent, (±)‐daurichromenic acid, is accomplished by formylation and oxidation in two steps.     

Synthesis of Spinochalcone B and Analogues

An efficient synthesis of spinochalcone B and its analogues is achieved from readily available 2H‐pyran.     

Creating cellulose fibres with excellent UV protective properties using moist CF4 plasma and ZnO nanoparticles

Weakly ionised gaseous plasma created in a moist tetrafluoromethane gas at a low pressure with an electrodeless radiofrequency discharge was applied to modify the surface properties of cellulose fibres. The plasma was used to increase the adsorption of zinc oxide (ZnO) nanoparticles such that cellulose fibres with good ultraviolet (UV) protective properties could be created. The UV protection factor (UPF) values of the ZnO-functionalised fibres were determined as a function of the plasma treatment time. The chemical and physical surface properties of the plasma-treated fibres were examined using scanning electron microscopy, X-ray photoelectron spectroscopy, and wettability tests. The quantity of zinc on the fibres was determined using inductively coupled plasma mass spectroscopy. The results indicated that 30 s of plasma treatment resulted in ZnO-functionalised samples with lower UPF values than samples without plasma treatment due to the creation of fluorine-rich functional groups on cellulose fibres and the agglomeration of ZnO nanoparticles. The highest UPF values (50+) were obtained when samples were treated with plasma for 10 s. These high UPF values were a result of the increased adsorption of uniformly distributed ZnO nanoparticles caused by fibres surface functionalization and roughening upon plasma treatment. Furthermore, the mechanical properties of textiles treated with moist CF₄ plasma for 10 s were slightly improved.     

New Synthetic Routes to Biologically Interesting Geranylated Flavanones and Geranylated Chalcones: First Total Synthesis of (±)‐Prostratol F,Xanthoangelol, and (±)‐Lespeol

A new and efficient synthetic approach to biologically interesting geranylated flavanones and geranylated chalcones is described. Thus, the first total syntheses of the geranylated flavanones (±)‐prostratol F ( 1 ), (±)‐8‐geranyl‐3′,4′,7‐trihydroxyflavanone ( 2 ), and (±)‐6‐geranyl‐5,7‐dihydroxy‐3′,4′‐dimethoxyflavanone ( 3 ) were carried out starting from 2,4‐dihydroxyacetophenone ( 10 ) and 2,4,6‐trihydroxyacethophenone ( 17 ) in five to six steps (Schemes 2 and 3). The geranylated chalcones xanthoangelol ( 4 ), 3‐geranyl‐2,3′,4,4′‐tetrahydroxychalcone ( 5 ), (±)‐lespeol ( 6 ), and lespeol derivatives (±)‐ 7 – 9 were synthesized starting from 2,4‐dihydroxyacetophenone ( 10 ) in three to four steps (Schemes 2 and 6).     

Fabrication of helical long-period fiber gratings by use of a CO2 laser

We present a method of helical long-period fiber grating (H-LPFG) fabrication by use of a CO2 laser for use as an optical torque sensor. A conventional optical fiber grating has periodic vertical index changes along its fiber axis, but a H-LPFG has a screw-type index modulation. The helical index modulation is obtained with the asymmetric index change caused by a single-side laser beam exposure. The H-LPFG shows peak shifts with codirectional or contradirectional torsion to the helix. Also, the polarization-dependent loss is measured to be relatively small compared with that of a conventional long-period fiber grating.     

Excited‐state energy dynamics of conjugated polycarbogermane oligomers: Introduction effects of germanium atom into π‐conjugated molecular system

Excited‐state energy dynamics of the conjugated polycarbogermane oligomers, poly{[1,4‐bis(thiophenyl)buta‐1,3‐diyne]‐alt‐(dimethylgermane)} (PBTBD‐DMG; n = 33), poly{[1,4‐bis‐(thiophenyl)buta‐1,3‐diyne]‐alt‐(diphethylgermane)} (PBTBD‐DPG; n = 12), poly{[1,4‐bis(phenyl)buta‐1,3‐diyne]‐alt‐(dimethylgermane)} (PBPBD‐DMG; n = 36), and poly{[1,4‐bis(phenyl)buta‐1,3‐diyne]‐alt‐(diphenylgermane)} (PBPBD‐DPG; n = 2), were investigated by steady‐state and picosecond time‐resolved fluorescence spectroscopies in liquid solution. The introduction effect of a germanium atom into π‐conjugated oligomer backbones and the substitution effect of a methyl or phenyl group on the germanium atom are discussed from solvent polarity‐dependent studies. Steady‐state and time‐resolved fluorescence studies on the thiophene‐containing polycarbogermane (PBTBD‐DMG and PBTBD‐DPG) oligomers revealed considerable solvent polarity‐dependent characteristics, whereas those of the phenylene‐containing polycarbogermane (PBPBD‐DMG and PBPBD‐DPG) oligomers do not significantly show such characteristics. As the solvent polarity increased from n‐hexane to tetrahydrofuran, the steady‐state fluorescence spectra of PBTBD‐DMG and PBTBD‐DPG oligomers were significantly redshifted, and their fluorescence lifetimes seemed to change from ～624 to ～46 ps. These results suggest that the excited‐state dynamics of PBTBD‐DMG and PBTBD‐DPG oligomers are related to an intramolecular charge transfer (ICT) emission process through (d‐p) π conjugation between the π‐conjugated system and unoccupied 4d orbitals of the germanium atom. These results are supported by quantum chemical (AM1 and CNDO/2) calculations. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1298–1306, 2002     

Transformations of 2,2,6-trimethyl-1,3-dioxen-4-one with heterocyclic amines and other amino compounds

Heterocyclic amines were acetoacetylated with 2,2,6-trimethyl-1,3-dioxen-4-one and the obtained compounds reacted on the reactive methylene group to give C-substituted products. Nitrosation, followed by reduction afforded a pyrazine derivative. Azido- or chloroacetamide were also acetoacetylated, with heterocyclic amines, the corresponding enamines were prepared and reduction of the azido group of 15 afforded compounds 22 and/or amides of substituted 3-oxobutanoic acid 23 . An X-ray structural determination of compound 23a revealed that the orientation about the double bond is Z.