bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of NIPAAm‐Ch gel to temperature changes and its effectiveness on nitrification as medium for immobilization
Authors: Yuan Linjiang , Kusuda Tetsuya , Satoh Hisashi 
Published: October 2006

AbstractIncrease in mass transport resistance is one of the major difficulties in immobilization by the use of gels. Functional gels can change their volume and inner structure depending on ambient conditions as stimuli and may reduce the difficulty as a novel immobilization matrix. The response of poly N‐isopropylacrylamide‐co‐chlorophyllin (NIPAAm‐Ch) gel to temperature changes and its performance on nitrification with nitrifiers immobilized by the gel were investigated in a continuous‐flow stirred‐tank reactor (CFSTR) with cyclic temperature changes. The gel with an immobilized nitrifier swelled and shrank alternately with 1.2–1.6‐fold volume change under a cyclic temperature change of 32–36°C with a period of 2 or 4 h in the reactor. Volume changes of the gel brought periodic changes of its structure that accelerated dissolved oxygen transfer and concentrated ammonium into, and as a result, promoted nitrification compared with that at constant temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 681–686, 2007
Enhanced properties of innovative laponite‐filled waterborne acrylic resin dispersions
Authors: Nobel M. L. , Mendes E. , Picken S. J. 
Published: October 2006

AbstractIn view of the possible future applications of waterborne automotive coatings, acrylic‐based nanocomposite dispersions were investigated by the simple mixing of aqueous laponite nanoparticle dispersions with acrylic resin dispersions. The mechanical, flow, and leveling properties of waterborne nanocomposite dispersion formulations containing increasing concentrations of silicate and nonvolatile components (nvc) in the acrylic dispersions were investigated. The results obtained were related to the morphological information obtained from transmission electron microscopy and wide‐angle X‐ray scattering measurements in liquid suspension or on the cured films. At low synthetic silicate loading when flow, leveling, and appearance properties were still acceptable for processing and application, a large increase in the modulus of the cured coating films was observed, which was a result of the special morphology of the laponite‐rich regions of the cured film. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 687–697, 2007
Influence of core–shell rubber particles synthesized with different initiation systems on the impact toughness of modified polystyrene
Authors: Gao Guanghui , Zhou Chao , Yang Haidong , Zhang Huixuan 
Published: October 2006

AbstractCore–shell poly(butadiene‐graft‐styrene) (PB‐g‐PS) rubber particles were synthesized with different initiation systems by emulsion grafting polymerization. These initiation systems included the redox initiators and an oil‐soluble initiator, 1,2‐azobisisobutyronitrile (AIBN). Then the PB‐g‐PS impact modifiers were blended with polystyrene (PS) to prepare the PS/PB‐g‐PS blends. In the condition of the same tensile yield strength on both samples, the Izod test showed that the notched impact strength of PS/PB‐g‐PS(AIBN) was 237.8 J/m, almost 7 times than that of the PS/PB‐g‐PS(redox) blend, 37.2 J/m. From transmission electron microscope (TEM) photographs, using the redox initiators, some microphase PS zones existed in the core of PB rubber particles, which is called “internal‐grafting.” This grafting way was inefficient on toughening. However, using AIBN as initiator, a great scale of PS subinclusion was seen within the PB particle core, and this microstructure increased the effective volume fraction of the rubber phase with a result of improving the toughness of modified polystyrene. The dynamic mechanical analysis (DMA) on both samples showed that the glass transition temperature (Tg) of rubber phase of PS/PB‐g‐PS(AIBN) was lower than that of PS/PB‐g‐PS(redox). As a result, the PB‐g‐PS(AIBN) had better toughening efficiency on modified polystyrene than the PB‐g‐PS(redox), which accorded with the Kerner approximate equation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 738–744, 2007
Mixture printing pastes from high substitued guar gum and alginates on reactive printing of viscose
Authors: Perrin Akçakoca Kumbasar E. 
Published: October 2006

AbstractThe rheology of binary mixtures of two alginates and one carboxymethyl guar has been measured. Two reactive dyes were printed from pastes based on mixtures. The printing and the final print (color yield, levelness, and fabric stiffness) were assessed. Most of the mixtures reacted in accordance with the dye, and interacted especially with one of the dyes for which CMG was used. However, it is seen that mixture of CMG with alginates can be used in reactive printing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 745–751, 2007
Effects of material parameters on the diffusion and sorption properties of wood‐flour/polypropylene composites
Authors: Steckel Vera , Clemons Craig M. , Thoemen Heiko 
Published: October 2006

AbstractComposites of wood in a thermoplastic matrix (wood–plastic composites) are considered a low maintenance solution to using wood in outdoor applications. Knowledge of moisture uptake and transport properties would be useful in estimating moisture‐related effects such as fungal attack and loss of mechanical strength. Our objectives were to determine how material parameters and their interactions affect the moisture uptake and transport properties of injection‐molded composites of wood‐flour and polypropylene and to compare two different methods of measuring moisture uptake and transport. A two‐level, full‐factorial design was used to investigate the effects and interactions of wood‐flour content, wood‐flour particle size, coupling agent, and surface removal on moisture uptake and transport of the composites. Sorption and diffusion experiments were performed at 20°C and 65 or 85% relative humidity as well as in water, and diffusion coefficients were determined. The wood‐flour content had the largest influence of all parameters on moisture uptake and transport properties. Many significant interactions between the variables were also found. The interaction between wood‐flour content and surface treatment was often the largest. The diffusion coefficients derived from the diffusion experiments were different from those derived from the sorption experiments, suggesting that different mechanisms occur. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 752–763, 2007
Synthesis, characterization, and flocculation characteristics of polyacrylamide‐grafted glycogen
Authors: Adhikary P. , Tiwari K. N. , Singh R. P. 
Published: October 2006

AbstractThe synthesis of glycogen‐g‐polyacrylamide (Gly‐g‐PAM) was carried out by a ceric ion‐induced solution polymerization technique. Six grades of graft copolymers were synthesized by the variation of catalyst and monomer concentrations. These graft copolymers were characterized by intrinsic viscosity measurements, FTIR spectroscopy, and X‐ray diffraction techniques. Flocculation performance of these graft copolymers were done in kaolin suspension. Of the above grades, the graft copolymer Gly‐g‐PAM 5, which has longer PAM chains, showed best flocculation performance. The flocculation performance of the graft copolymer was compared with commercial flocculants and other PAM‐grafted flocculants developed so far in the authors' laboratory. In all the cases, it was found that the graft copolymer performed the best. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 773–778, 2007
Effect of compatibilizer distribution on the blends of starch/biodegradable polyesters
Authors: Yu Long , Dean Katherine , Yuan Qiang , Chen Ling , Zhang Ximei 
Published: October 2006

AbstractVarious blends of gelatinized cornstarch and two biodegradable polyesters, PCL or PBSA, were prepared via melt processing using a twin‐screw extruder. Distribution of a compatibilizer MDI (methylenediphenyl diisocyanate) was controlled through the processing conditions employed and its effect on the resultant microstructure and mechanical properties of the blends were studied by SEM, DSC, TGA, and mechanical testing. When the MDI was distributed in the starch phase, the highly reactive isocyanate groups in MDI were most probably consumed by water that resulted in an overall weakening of its compatibilizing effect. Modulus, yield strength, and impact strength were increased by more than 35, 40, and 300%, respectively, when MDI was distributed in the polyester phase first rather than in the starch phase prior to blending. SEM observation showed that the interface between starch and the polyesters was improved significantly while DSC and TGA investigation also confirmed the microstructural difference. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 812–818, 2007
Incorporation of azobenzene chromophore into poly(amide‐imide)
Authors: Balogh D. T. , Carvalho A. J. F. 
Published: October 2006

AbstractPoly(amide‐imide)s (PAI) bearing azobenzene chromophore groups were prepared by allowing a hydroxyl‐containing azobenzene dye (Disperse Red 1) to react with and reactive‐terminated PAI with weight–average molecular weights ranging from ∼ 1.2 to 2.0 × 104 g/mol. Such PAI were prepared by the condensation of trimellitic anhydride (TMA) and 4,4′‐methylene diphenyl diisocyanate (MDI). The final polymers presented a deep red color, with an absorption maxima in N,N‐dimethylformamide (DMF) solution at 490 nm, close to the azobenzene reactant used (Disperse Red 1) and molecular weights slightly higher than the pristine polymer, showing that the azo chromophore incorporation reaction does not lead to side reactions. The azofunctionalized polymer presented a high Tg value (170°C) that could be increased by a thermal curing process to 240°C. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 841–847, 2007
Solid‐state grafting of succinic anhydride onto poly(vinyl alcohol)
Authors: Zhou Zheng‐Fa , Xu Wei‐bing , He Dian , Fan Ji‐xian , Yu Feng , Ren Feng‐Mei 
Published: October 2006

AbstractThe graft reaction of succinic anhydride onto poly(vinyl alcohol) (PVA) was catalyzed by p‐toluenesulfonic acid monohydrate in solid state. The infrared spectra and 1H‐NMR spectra confirmed that succinic anhydride was successfully grafted onto PVA backbone. The influences of reaction temperature, reaction time, the amount of succinic anhydride, and the amount of catalyst on the graft reaction were studied. Uncrosslinked PVA graft copolymer with grafting degree up to about 6.5% could be obtained under low reaction temperature, short reaction time, and low amount of catalyst, whereas crosslinked PVA with high gel content could be obtained under high reaction temperature, long reaction time, and high amount of catalyst. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 848–852, 2007
Metabolic flux analysis of the two astaxanthin‐producing microorganisms Haematococcus pluvialis and Phaffia rhodozyma in the pure and mixed cultures
Authors: Dong Qing‐Lin , Zhao Xue‐Ming , Ma Hong‐Wu , Xing Xiang‐Ying , Sun Nai‐Xia 
Published: October 2006

AbstractThe two major astaxanthin‐producing microorganisms Phaffia rhodozyma and Haematococcus pluvialis exhibited elevated astaxanthin yields under the mixed culture regime, and the changes in flux distribution were investigated by means of metabolic flux analysis (MFA). In the mixed culture of the two strains, the carbon flux towards astaxanthin formation in P. rhodozyma increased by 20%, which may be due to the enriched oxygen evolved through the photosynthesis of H. pluvialis. On the other hand, the uptake of pyruvate and CO2 excreted by P. rhodozyma also facilitated astaxanthin synthesis in H. pluvialis, which reduced 33% of the carbon flux exported from Calvin cycle to the catabolic pathway, and in turn raised the carbon flux to glyceraldehyde‐3‐phosphate by 25%. As a result, the carbon flux diverted to astaxanthin synthesis increased 2.8‐fold in comparison with that in the pure culture.
The development of China's medical biotech industry needs to be driven by innovation
Authors: Yu Zailin , Dai Yuehan 
Published: October 2006

AbstractThe Chinese biotech industry is going through a period of fast growth, and with its huge population, China is predicted to be the biggest single‐country market in the world. However, the Chinese biotech industry has to tackle the critical issue of innovation, which should be the driving force for China's development into an advanced and responsible country. Here, in this article, the authors review the history of the Chinese biotech industry, exemplified by the development of genetically engineered drugs during the last 20 years, and also point out its the future.
A complete protein pattern of cellulase and hemicellulase genes in the filamentous fungus Trichoderma reesei
Authors: Ouyang Jia , Yan Ming , Kong Dechong , Xu Lin 
Published: October 2006

AbstractThe complete protein pattern of cellulase and hemicellulase genes was studied through the Genome‐wide analysis in Trichoderma reesei. The genome database revealed the presence of 39 ORFs encoding related proteins, including 32 enzymes with a catalysis domain related to cellulases and hemicellulases and 7 related proteins with a cellulose‐binding module (CBM). Ten of these encoded yet undescribed enzymes, including six novel β‐glucosidases or xylosidases, two putative xylanases and two undescribed mannases. To better illustrate the relation of these 39 related proteins, four groups were created and analyzed by phylogenetic analysis: group A corresponding to xylanases, group B belonging to mannases and acting to degrade mannan; group C containing all known and putative cellulose‐degrading proteins that have highly conserved CBMs; and group D containing β‐glucosidase and β‐xylosidase. Group D was the largest group, in which 8 β‐glucosidases appeared to be non‐secreted proteins.
Investigating pH and Cu (II) effects on lipase activity and enantioselectivity via kinetic and spectroscopic methods
Authors: Xu Tian‐Wen , Xu Jian‐He , Yu Wei , Zhong Ju‐Hua 
Published: October 2006

AbstractFor Candida rugosa lipase (CRL) catalyzed hydrolysis of racemic 1‐phenethyl acetate, both the weakly acidic pH (pH 6.0) and the addition of 1 mM copper (II) ion enhanced the enzyme activity and enantioselectivity (E value) about twofold, as compared with that under neutral pH and noadditive conditions. The decrease of activation free energy (ΔG) and increase of kcat(R)/kcat(S) at weakly acidic pH and/or in the presence of copper (II) characterized the kinetic behavior of CRL. On the other hand, for providing reasonable insights into the catalytic mechanism and the structural basis for enantioselectivity alteration, spectroscopic techniques were employed to probe conformational changes of the enzyme in each medium assayed. The fluorescence emission spectra revealed that pH and copper (II) might exert different effects on the microenvironment of Trp residue and thereby on the protein conformation, which could be further verified by UV‐visible and Raman spectra. The conformational modulation of CRL associated with either pH or copper (II) concentration in the reaction medium could be attributed to the flexible and sensitive conformation of the enzyme, which is responsible for the significant variation of apparent activity and enantioselectivity with the tuning of biocatalyst microenvironment.
Effects of PKC ζ on early genome transcription activation in mouse 1‐cell stage fertilized eggs
Authors: Yu Bing‐zhi , Fu Wei , Su Wen‐hui , Yu Da‐hai , Zhang Zhe , Feng Chen 
Published: October 2006

AbstractEffects of PKC ζ on the activation of embryonic transcription in 1‐cell stage fertilized mouse eggs were explored. The effects of PKC antagonist calphostin C and PKC ζ specific inhibitor on the activation of embryonic early transcription were observed by Western blotting and cell immunofluorescence. PKC activity increased gradually from G1 phase to late G2 phase in mouse 1‐cell stage fertilized eggs, and reached a maximum in G2 stage. Calphostin C inhibited PKC activity by about 47% in 1‐cell stage fertilized eggs. Calphostin C inhibited early transcription in 1‐cell stage fertilized eggs (p < 0.01). PKC ζ‐Thr410 in G2 were about 27% and 110% higher than those in G1 phase of 1‐cell stage fertilized eggs and MII oocytes, respectively. PKC ζ specific inhibitor can also inhibit early transcription in 1‐cell stage fertilized eggs (p < 0.05). The results suggest that PKC ζ participates in early transcription activation in mouse 1‐cell stage fertilized eggs. Copyright © 2006 John Wiley & Sons, Ltd.
Upconversion Between 4f–5d Excited States in Tm2+‐Doped CsCaCl3, CsCaBr3, and CsCaI3
Authors: Grimm J. , Beurer E. , Gerner P. , Güdel H. U. 
Published: October 2006

AbstractNear‐infrared to visible upconversion luminescence in CsCaCl3:Tm2+, CsCaBr3:Tm2+ and CsCaI3:Tm2+ is presented and analysed. The upconversion process involves exclusively the 4f–5d excited states of Tm2+, which is a novelty among upconversion materials. The presence of more than one long‐lived 4f–5d excited state is the prerequisite for this. Multiple emissions from Tm2+ are observed in the title compounds. This is made possible by the favourable energy structure within the 4f–5d states and the low phonon energies of the materials. The energy positions of the relevant 4f–5d states, and thus the photophysical and light emission properties, are affected by the chemical variation along the series. The upconversion efficiency increases from chloride to iodide and the mechanism is found to be a combination of absorption and energy‐transfer steps.
Atoms‐in‐Molecules Analysis of Extended Hypervalent Five‐Center, Six‐Electron (5c–6e) C2Z2O Interactions at the 1,8,9‐Positions of Anthraquinone and 9‐Methoxyanthracene Systems
Authors: Nakanishi Waro , Nakamoto Takashi , Hayashi Satoko , Sasamori Takahiro , Tokitoh Norihiro 
Published: October 2006

AbstractTo clarify the nature of five‐center, six‐electron (5c–6e) C2Z2O interactions, atoms‐in‐molecules (AIM) analysis has been applied to an anthraquinone, 1,8‐(MeZ)2ATQ (1(Z=Se),2(Z=S), and3(Z=O)), and a 9‐methoxyanthracene system, 9‐MeO‐1,8‐(MeZ)2ATC (4(Z=Se),5(Z=S), and6(Z=O)), as well as 1‐(MeZ)ATQ (7(Z=Se),8(Z=S), and9(Z=O)) and 9‐MeO‐1‐(MeZ)ATC (10(Z=Se),11(Z=S), and12(Z=O)). The total electronic energy density (Hb(rc)) at the bond critical points (BCPs), an appropriate index for weak interactions, has been examined for 5c–6e C2Z2O and 3c–4e CZO interactions of the np(O)⋅⋅⋅σ*(ZC) type in1–12. Some hydrogen‐bonded adducts were also re‐examined for convenience of comparison. The total electronic energy densities varied in the following order: O⋅⋅⋅O (3:Hb(rc)=0.0028 au)=O⋅⋅⋅O (6: 0.0028 au)>O⋅⋅⋅O (9: 0.0025 au)≥NN⋅⋅⋅HF (0.0024 au)≥O⋅⋅⋅O (12: 0.0023 au)≫H2O⋅⋅⋅HOH (0.0015 au)>S⋅⋅⋅O (8: 0.0013 au)=S⋅⋅⋅O (2: 0.0013 au)≥S⋅⋅⋅O (11: 0.0012 au)=S⋅⋅⋅O (5: 0.0012 au)>HF⋅⋅⋅HF (0.0008 au)=Se⋅⋅⋅O (10: 0.0008 au)=Se⋅⋅⋅O (4: 0.0008 au)≥Se⋅⋅⋅O (1: 0.0007 au)≥Se⋅⋅⋅O (7: 0.0006 au)≫HCN⋅⋅⋅HF (−0.0013 au).Hb(rc) values for S⋅⋅⋅O were predicted to be smaller than the hydrogen bond of H2O⋅⋅⋅HOH andHb(rc) values for Se⋅⋅⋅O are very close to or slightly smaller than that for HF⋅⋅⋅HF in both the ATQ and 9‐MeOATC systems. In the case of Z=Se and S,Hb(rc) values for 5c–6e C2Z2O interactions are essentially equal to those for 3c–4e CZO if Z is the same. The results demonstrate that two np(O)⋅⋅⋅σ*(ZC) 3c–4e interactions effectively connect through the central np(O) orbital to form the extended hypervalent 5c–6e system of the σ*(CZ)⋅⋅⋅np(O)⋅⋅⋅σ*(ZC) type for Z=Se and S in both systems. Natural bond orbital (NBO) analysis revealed that ns(O) also contributes to some extent. The electron charge densities at the BCPs, NBO analysis, and the total energies calculated for1–12, together with the structural changes in the PhSe derivatives, support the above discussion.
Methyl Vinyl Ketone+OH and Methacrolein+OH Oxidation Reactions: A Master Equation Analysis of the Pressure‐ and Temperature‐Dependent Rate Constants
Authors: Ochando‐Pardo Montserrat , Nebot‐Gil Ignacio , González‐Lafont Àngels , Lluch José M. 
Published: October 2006

AbstractHigh‐level electronic structure calculations and master equation analyses were carried out to obtain the pressure‐ and temperature‐dependent rate constants of the methyl vinyl ketone+OH and methacrolein+OH reactions. The balance between the OH addition reactions at the high‐pressure limit, the OH addition reactions in the fall‐off region, and the pressure‐independent hydrogen abstractions involved in these multiwell and multichannel systems, has been shown to be crucial to understand the pressure and temperature dependence of each global reaction. In particular, the fall‐off region of the OH addition reactions contributes to the inverse temperature dependence of the rate constants in the Arrhenius plots, leading to pressure‐dependent negative activation energies. The pressure dependence of the methyl vinyl ketone+OH reaction is clearly more important than in the case of the methacrolein+OH reaction owing to the weight of the hydrogen abstraction process in this second system. Comparison of the theoretical rate constants and the experimental measurements shows quite good agreement.
MTO Schiff‐Base Complexes: Synthesis, Structures and Catalytic Applications in Olefin Epoxidation
Authors: Zhou Ming‐Dong , Zhao Jin , Li Jun , Yue Shuang , Bao Chang‐Nian , Mink Janos , Zang Shu‐Liang , Kühn Fritz E. 
Published: October 2006

AbstractSeveral Schiff‐base ligands readily form complexes with methyltrioxorhenium(VII) (MTO) by undergoing a hydrogen transfer from a ligand‐bound OH group to a ligand N atom. The resulting complexes are stable at room temperature and can be handled and stored in air without problems. Due to the steric demands of the ligands they display distorted trigonal‐bipyramidal structures in the solid state, as shown by X‐ray crystallography, with the O− moiety binding to the Lewis acidic Re atom and the Re‐bound methyl group being located either in cis or trans position to the Schiff base. In solution, however, the steric differences seem not to be maintained, as can be deduced from 17O NMR spectroscopy. Furthermore, the Schiff‐base ligands exchange with donor ligands. Nevertheless, the catalytic behaviour is influenced significantly by the Schiff bases coordinated to the MTO moiety, which lead either to high selectivities and good activities or to catalyst decomposition. A large excess of ligand, in contrast to the observations with aromatic N‐donor ligands, is detrimental to the catalytic performance as it leads to catalyst decomposition.
Improved translation efficiency of injected mRNA during early embryonic development
Authors: Fink Maria , Flekna Gabriele , Ludwig Alfred , Heimbucher Thomas , Czerny Thomas 
Published: October 2006

AbstractInjection techniques are a powerful approach to study gene function in fish and frog model systems. In particular, in vitro transcribed mRNA is broadly used for such misexpression experiments. Sequence elements flanking the coding region, such as untranslated repeats and polyadenylation sequences, are known to affect the stability and the translation efficiency of mRNA. Here we show that in early embryos, poly(A) signals strongly contribute to the activity of the injected mRNA. Of interest, they only marginally affect mRNA stability, whereas the translation efficiency is dramatically enhanced. Combination of a poly(A) tail and an SV40 late poly(A) signal leads to highly synergistic effects of the two elements for injected mRNA. Compared with established vector systems, we detected a 20‐fold improvement for mRNA derived from the novel transcription vector pMC. Developmental Dynamics 235:3370–3378, 2006. © 2006 Wiley‐Liss, Inc.