bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laccase‐catalysed oxidation of aqueous triclosan
Authors: Kim Young‐Jin , Nicell James A 
Published: May 2006

AbstractA study was conducted on the ability of laccase from Trametes versicolor to catalyse the oxidation of triclosan, an antibacterial agent of significant commercial importance and environmental concern. Laccase was able to catalyse the transformation of triclosan under a variety of conditions and achieve a substantial decrease in toxicity of the reaction mixture. The optimal pH for triclosan transformation was approximately 5, with a broad optimum in the range 4–6. Treatment could be achieved at elevated temperatures, but at the expense of higher rates of inactivation. Treatment efficiency and reaction rates were substantially improved through the use of a protective additive, poly(ethylene glycol) (PEG‐35 000), and a mediator, 2,2′‐azino‐bis(3‐ethylbenzthiazoline)‐6‐sulfonic acid (ABTS). However, both compounds negatively affected the toxicities of treated solutions. The presence of ions including sulfite, sulfide, cyanide, chloride, iron(III) and copper(II) resulted in reduced treatment efficiency. Copyright © 2006 Society of Chemical Industry
Metabolic GHB precursor succinate binds to γ‐hydroxybutyrate receptors: Characterization of human basal ganglia areasnucleus accumbensandglobus pallidus
Authors: Molnár Tünde , Fekete Erzsébet Kútiné , Kardos Julianna , Simon‐Trompler Edit , Palkovits Miklós , Emri Zsuzsa 
Published: May 2006

AbstractBinding of the metabolic γ‐hydroxybutyrate (GHB) precursor succinate to NCS‐382‐sensitive [3H]GHB‐labeled sites in crude synaptosomal or purified synaptic membrane fractions prepared from the humannucleus accumbens(NA),globus pallidus(GP) and rat forebrain has been shown. This site can be characterized by binding of ethyl hemisuccinate and gap‐junction blockers, including carbenoxolone hemisuccinate and β‐GRA. There was no significant binding interaction between GABABreceptor ligands (CGP 55845, (R)‐baclofen) and these [3H]GHB‐labeled sites. GHB, NCS‐382 and succinate binding profile of [3H]GHB‐labeled sites in rat forebrain, human NA or GP synaptic membranes were similar. The synaptic fraction isolated from the rat forebrain was characterized by GHB binding inhibition constants:Ki,NCS‐382= 1.2 ± 0.2 μM,Ki,GHB= 1.6 ± 0.3 μM andKi,SUCCINATE= 212 ± 66 μM. In crude membranes containing mainly extrasynaptic membranes, distinct GHB and GABABreceptor sites were found in the NA. By contrast, extrasynaptic GABABreceptor sites of rat forebrain and GP were GHB‐ and succinate‐sensitive, respectively. The heterogeneity of GABABsites found in native membranes indicates GABABreceptor‐dependent differences in GHB action. Based on these findings, we suggest that succinate (and possibly drugs available as succinate salt derivatives) can mimic some of the actions of GHB. © 2006 Wiley‐Liss, Inc.
Design and Control of Copolymer Composition Distribution in Living Radical Polymerization Using Semi‐Batch Feeding Policies: A Model Simulation
Authors: Wang Rui , Luo Yingwu , Li Bogeng , Sun Xiaoying , Zhu Shiping 
Published: May 2006

AbstractSummary: Although controlled/living radical copolymerization has been extensively studied, the control of copolymer composition distribution receives little attention. In this paper, taking RAFT copolymerization as an example, we develop a mathematical model and simulate copolymerization systems with various reactivity ratios. It is demonstrated that through semi‐batch operations with programmed profiles of slow monomer feeding rate, precise control over copolymer composition distribution (uniform and designed gradient distributions) along polymer chain can be achieved. It is also found that the semi‐batch operations have lower rates of polymerization than their batch counterparts. The reason for this difference is analyzed, and the magnitude depends on the reactivity ratios and targeted copolymer composition. The improvement of the semi‐batch rate by distributing a part of the initiator amount to the monomer feeding tank is found to be minor.Model‐based design and control over composition distribution of gradient copolymers implemented by semi‐batch operations.magnified imageModel‐based design and control over composition distribution of gradient copolymers implemented by semi‐batch operations.
NF‐κB and cancer: Mechanisms and targets
Authors: Karin Michael 
Published: May 2006

AbstractIn addition to being a central coordinator of immune responses, NF‐κB signaling also plays a critical role in cancer development and progression and it may determine the response to therapy. NF‐κB activation was shown to provide a critical mechanistic link between inflammation and cancer and is a major factor that controls the ability of both preneoplastic and malignant cells to resist apoptosis‐based tumor surveillance mechanisms. NF‐κB may also be involved in regulation of tumor angiogenesis and invasiveness. Importantly, NF‐κB and the signaling pathways that mediate its activation have become attractive targets for development of new chemopreventive and chemotherapeutic approaches. © 2006 Wiley‐Liss, Inc.
Transcriptional regulation via cysteine thiol modification: A novel molecular strategy for chemoprevention and cytoprotection
Authors: Na Hye‐Kyung , Surh Young‐Joon 
Published: May 2006

AbstractChemoprevention refers to the use of defined nontoxic chemical regimens to inhibit, reverse, or retard the process of multistage carcinogenesis that involves multiple signal transduction events. Identification of signaling molecules associated with carcinogenesis as prime targets of chemopreventive agents has become an area of great interest. Recent studies have implicated cysteine thiols present in various transcription factors, such as NF‐κB, AP‐1, and p53 as redox sensors in transcriptional regulation of many genes essential for maintaining cellular homeostasis. Some chemopreventive and cytoprotective agents have been found to target cysteine thiols present in key transcription factors or their regulators, thereby suppressing aberrant over‐activation of carcinogenic signal transduction or restoring/normalizing or even potentiating cellular defense signaling. The focus of this review is the oxidation or covalent modification of thiol groups present in key representative redox‐sensitive transcription factors and their regulating molecules as a unique strategy for molecular target‐based chemoprevention and cytoprotection. © 2006 Wiley‐Liss, Inc.
In vivo estimation of the flow‐driven adiabatic inversion efficiency for continuous arterial spin labeling: A method using phase contrast magnetic resonance angiography
Authors: O'Gorman Ruth L. , Summers Paul E. , Zelaya Fernando O. , Williams Steven C. R. , Alsop David C. , Lythgoe David J. 
Published: May 2006

AbstractThe accurate quantification of perfusion with arterial spin labeling (ASL) requires consideration of a number of factors, including the efficiency of the inversion and control pulses used for spin labeling. In this study the effects of spin velocity on continuous ASL efficiency when using the amplitude modulated control strategy were investigated using simulations of the Bloch equations. The inversion efficiency was determined in vivo by combining the simulations with phase‐contrast velocity mapping data acquired at the level of the tagging plane. Using this novel method, an average inversion efficiency of 69% was calculated for a group of 28 subjects, in good agreement with experimental data reported previously. There was, however, a large range in inversion efficiency measured across the subject group (50–76%), indicating that the velocity dependence of the amplitude modulated control efficiency may introduce additional variability into the perfusion calculations if not properly taken into account. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Effect of partial bladder outlet obstruction on nitrotyrosine levels and their correlation with contractile function
Authors: Mannikarottu Anita , Lin Alpha Dian‐Yu , Whitebeck Catherine , Leggett Robert , Kogan Barry , Levin Robert 
Published: May 2006

AbstractAimsIt has been demonstrated that partial bladder outlet obstruction (PBOO) causes free radical generation that, in turn, results in cellular and subcellular damage. We tested the hypothesis that nitration of proteins is associated with contractile dysfunctions in obstructive bladder disease.MethodsThirty rabbits were subjected to 1–28 days of partial outlet obstruction. Sham operated rabbits served as controls. Western blotting was used to determine the amount of nitrotyrosine level at the protein level. At each time point, isolated strips of bladder body were mounted in individual baths and the contractile response to field stimulation (FS), carbachol, and KCl determined.ResultsBladder weight increased rapidly during the first 7 days and then increased slowly thereafter. There was a fourfold increase in the amount of nitrotyrosine in the 7 day obstructed groups when compared to sham controls and the levels remain elevated at 14 and 28 days of obstruction. Contractile dysfunction in response to FS (8 and 32 Hz) was noted as early as 1 day after obstruction and increased progressively over the study period. The decrease in response to carbachol and KCl was significant only after 3 days of obstruction and the progressive increase in dysfunction was slower than with FS.ConclusionsPBOO is accompanied by an increase in nitrotyrosine, a marker of free radical damage. Simultaneously there was a progressive decrease in contractility of detrusor smooth muscles (DSMs). Nitrotyrosine may be usable as a marker of free radical damage and reperfusion injury. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
A heuristic for maximizing the number of on‐time jobs on two uniform parallel machines
Authors: Koulamas Christos , Kyparisis George J. 
Published: May 2006

AbstractWe consider the problem of maximizing the number of on‐time jobs on two uniform parallel machines. We show that a straightforward extension of an algorithm developed for the simpler two identical parallel machines problem yields a heuristic with a worst‐case ratio bound of at least
$5\over 3$. We then show that the infusion of a “look ahead” feature into the aforementioned algorithm results in a heuristic with the tight worst‐case ratio bound of $3\over 2$, which, to our knowledge, is the tightest worst‐case ratio bound available for the problem. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006
Effects of comonomer sequential structure on thermal and crystallization behaviors of biodegradable poly(butylene succinate‐co‐butylene terephthalate)s
Authors: Li Faxue , Xu Xinjian , Hao Qinghui , Li Qiaobo , Yu Jianyong , Cao Amin 
Published: May 2006

AbstractIn this work, new investigations on the effect of comonomer sequential structure on the thermal and crystallization behaviors and biodegradability have been implemented for the biodegradable poly(butylene succinate‐co‐butylene terephthalate) (PBST) as well as aliphatic poly(butylene succinate) (PBS). At first, these copolyesters were efficiently synthesized from dimethyl succinate and/or dimethyl terephthalate and 1,4‐butanediol via condensation polymerization in bulk. Subsequently, their molecular weights and macromolecular chain structures were analyzed by gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy. By means of differential scanning calorimeter (DSC) and wide‐angle X‐ray diffractometer (WAXD), thermal and crystallization behaviors of these synthesized aromatic–aliphatic copolyesters were further explored. It was demonstrated that the synthesized copolyesters were revealed to have random comonomer sequential structures with thermal and crystallization properties strongly depending on their comonomer molar compositions, and that crystal lattice structures of the new crystallizable copolyesters shifted from the monoclinic crystal of semicrystalline PBS to triclinic lattice of the poly(butylene terephthalate) (PBT) with increasing the terephthalate comonomer composition, and the minor comonomer components were suggested to be trapped in the crystallizable component domains as defects. In addition, the enzymatic degradability was also characterized for the copolyesters film samples. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 1635–1644, 2006
Fabrication of suspended GaN microstructures using GaN‐on‐patterned‐silicon (GPS) technique
Authors: Yang Z. , Wang R. N. , Jia S. , Wang D. , Zhang B. S. , Lau K. M. , Chen K. J. 
Published: May 2006

AbstractWe demonstrate a technique for fabricating suspended gallium nitride (GaN) microstructures without direct etching of GaN. The process combines a selective area growth of GaN‐on‐patterned‐silicon substrate (GPS) and a subsequent sacrificial wet etching of the silicon under the GaN structures. Both anisotropic and isotropic wet etching techniques are used to carry out the sacrificial etching. The pattern‐dependent lateral growth property of GaN growth is also discussed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Crystallization of GaN by HVPE on pressure grown seeds
Authors: Grzegory I. , Lucznik B. , Bockowski M. , Pastuszka B. , Kamler G. , Nowak G. , Krysko M. , Krukowski S. , Porowski S. 
Published: May 2006

AbstractGrowth of GaN under pressure from solution in gallium results in almost dislocation free plate‐like crystals but with size limited to approx. 1 cm (lateral) and 100 µm (thickness). On the other hand, deposition of GaN by HVPE on the pressure grown substrates allows stable crystallization with rates of a few hundreds µm/h. The crystals with a thickness exceeding 2 mm are grown in this way. However, in these thick GaN crystals grown directly on almost dislocation free substrates quite high number of dislocations appears if the crystal thickness exceeds certain critical value probably due to a small lattice mismatch between GaN grown by HVPE and the heavily doped pressure grown substrates Since the critical thickness for defect generation is of the order of 100 µm, almost dislocation free layers (density below 104 cm–2) thinner than 100 µm were grown. The pressure grown substrates were then removed by mechanical polishing, or conductivity sensitive electrochemical etching (for strongly n‐type substrates). Then the HVPE low dislocation density GaN platelets were used as substrates for the growth of a few mm thick bulk GaN crystals. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐quality InN grown on KOH wet etched N‐polar InN template by RF‐MBE
Authors: Muto D. , Naoi H. , Araki T. , Kitagawa S. , Kurouchi M. , Na H. , Nanishi Y. 
Published: May 2006

AbstractWe have succeeded in dramatically decreasing the density of dislocations in InN by regrowing InN films on micro‐facetted N‐polar InN templates. The micro‐facetted N‐polar InN templates were formed by wet etching in a 10 mol/l KOH solution. InN films were regrown on the micro‐facetted N‐polar InN templates and on flat surface N‐polar InN templates for comparison by radio‐frequency plasma‐assisted molecular beam epitaxy. InN regrown on micro‐facetted InN had considerably smaller twist distribution than that grown on the flat InN templates. From transmission electron microscopy observation, it was confirmed that the InN grown on the micro‐facetted InN template had much lower density of dislocations than that grown on the flat InN template, and moreover the propagation of edge dislocations was almost completely terminated at the interface between the regrown InN and the micro‐facetted InN template. Based on the results, we propose that regrowth of InN on micro‐facetted InN templates is an effective way to obtain high‐quality InN films. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
1.5 µm luminescence of silicon nanowires fabricated by thermal evaporation of SiO
Authors: Jia G. , Kittler M. , Su Z. , Yang D. , Sha J. 
Published: May 2006

AbstractSilicon nanowires (NWs) fabricated by thermal evaporation of SiO were studied by cathodoluminescence. A band around 1550 nm (0.8 eV) was observed. It appears above 225 K and its intensity increases with increasing temperature. The broad band consists of the defect‐related D1 and D2 lines and is supposed to be formed by extended defects within the NWs that are decorated with oxygen. Moreover, luminescence bands are found that are related to Si oxide and/or the interface between Si and Si oxide. In addition, the Si band‐to‐band line and the G center are observed. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Promoting student engagement in science: Interaction rituals and the pursuit of a community of practice
Authors: Olitsky Stacy 
Published: May 2006

AbstractThis study explores the relationship between interaction rituals, student engagement with science, and learning environments modeled on communities of practice based on an ethnographic study of an eighth grade urban magnet school classroom. It compares three interactional events in order to examine the classroom conditions and teacher practices that can foster successful interaction rituals (IRs), which are characterized by high levels of emotional energy, feelings of group membership, and sustained interest in the subject. Classroom conditions surrounding the emergence of successful IRs included mutual focus, familiar symbols and activity structures, the permissibility of some side‐talk, and opportunities for physical and emotional entrainment. Sustained interest in the topic beyond the duration of the IR and an increase in students' helping each other learn occurred more frequently when the mutual focus consisted of science‐related symbols, when there were low levels of risk for participants, when activities involved sufficient challenge and time, and when students were positioned as knowledgeable and competent in science. The results suggest that successful interaction rituals can foster student engagement with topics that may not have previously held interest and can contribute to students' support of peers' learning, thereby moving the classroom toward a community‐of‐practice model. © 2006 Wiley Periodicals, Inc. J Res Sci Teach
Debaryomyces hansenii — an extremophilic yeast with biotechnological potential
Authors: Breuer Uta , Harms Hauke 
Published: May 2006

AbstractWe illuminate the ecological, physiological and genetic characteristics of the yeast Debaryomyces hansenii in the view of our belief that this metabolically versatile, non‐pathogenic, osmotolerant and oleaginous microorganism represents an attractive target for fundamental and applied biotechnological research. To this end, we give a broad overview of extant biotechnological procedures using D. hansenii, e.g. in the manufacture of various foods, and propose research into the heterologous synthesis of a range of fine chemicals. Copyright © 2006 John Wiley & Sons, Ltd.
M[B(CN)4]2: Zwei neue Tetracyanoborate mit zweiwertigen Kationen (M = Zn, Cu)
Authors: Neukirch Michael , Tragl Sonja , Meyer H.‐Jürgen , Küppers Torsten , Willner Helge 
Published: May 2006

AbstractM[B(CN)4]2: Two new Tetracyanoborate Compounds with divalent Cations (M = Zn, Cu)The reaction of ZnO or CuO with [H3O][B(CN)4] in aqueous solution yielded single crystals of Zn[B(CN)4]2 and Cu[B(CN)4]2, respectively. The compounds were characterized by single‐crystal X‐ray diffraction. Zn[B(CN)4]2 ($P{\bar 3}m{\rm 1}$ (no. 164), a = b = 7.5092(9) Å, c = 6.0159(6) Å, Z = 1) crystallizes isotypic with Hg[B(CN)4]2. The structure of Cu[B(CN)4]2 (C2/m (no. 12), a = 13.185(3) Å, b = 7.2919(9) Å, c = 6.029(1) Å, β = 93.02(2)°, Z = 2) can be considered as a super‐structure, resulting from Jahn‐Teller distortion of the Cu2+ ions. Magnetic measurements were performed for the copper compound. Vibrational spectra and thermal stabilities were compared with the known mercury(II) tetracyanoborate.
Synthese und Kristallstruktur des Azidoberyllats (Ph4P)2[Be(μ‐OSiMe3)(N3)2]2
Authors: Neumüller Bernhard , Dehnicke Kurt 
Published: May 2006

AbstractSynthesis and Crystal Structure of the Azido Beryllate (Ph4P)2[Be(μ‐OSiMe3)(N3)2]2(Ph4P)2[Be2F6] reacts with excess trimethylsilylazide in acetonitrile solution, accompanied by a hydrolytic side‐reaction to give the azido beryllate (Ph4P)2[Be(μ‐OSiMe3)(N3)2]2 (1) as colourless, non‐explosive crystals. 1 was characterized by IR spectroscopy and by single crystal X‐ray determination.1: Space group ${\rm P}{\bar 1}$, Z = 1, lattice dimensions at 193 K: a = 1026.9(1), b = 1184.0(1), c = 1352.1(1) pm, α = 73.50(1)°, β = 74.35(1)°, γ = 64.66(1)°, R1 = 0.0543. The complex anion of 1 forms centrosymmetric units with symmetry Ci via Be2O2 four‐membered rings with Be–O distances of 159.2(7) and 168.7(7) pm, and terminally bonded azide groups.
Die neuen Schichtsilicate Ba3Si6O9N4 und Eu3Si6O9N4
Authors: Stadler Florian , Schnick Wolfgang 
Published: May 2006

AbstractThe New Layer‐Silicates Ba3Si6O9N4 and Eu3Si6O9N4The new oxonitridosilicate Ba3Si6O9N4 has been synthesized in a radiofrequency furnace starting from BaCO3, amorphous SiO2 and Si3N4. The reaction temperature was at about 1370 °C. The structure of the colorless compound has been determined by single‐crystal X‐ray diffraction analysis (Ba3Si6O9N4, space group P3 (no. 143), a = 724.9(1) pm, c = 678.4(2) pm, V = 308.69(9)· 106 pm3, Z = 1, R1 = 0.0309, 1312 independent reflections, 68 refined parameters). The compound is built up of corner sharing SiO2N2 tetrahedra forming corrugated layers between which the Ba2+ ions are located. Substitution of barium by europium leads to the isotypic compound Eu3Si6O9N4. Because no single‐crystals could be obtained, a Rietveld refinement of the powder diffractogram was conducted for the structure refinement (Eu3Si6O9N4, space group P3 (no. 143), a = 711.49(1) pm, c = 656.64(2) pm, V = 287.866(8) ·106 pm3, Rp = 0.0379, RF2 = 0.0638). The 29Si MAS‐NMR spectrum of Ba3Si6O9N4 shows two resonances at −64.1 and −66.0 ppm confirming two different crystallographic Si sites.
Die Reaktion von AlCl mit H2O in festem Argon: IR‐matrixspektroskopischer Nachweis von HAl(Cl)OH
Authors: Köppe R. 
Published: May 2006

AbstractThe Reaction of AlCl with H2O in Solid Argon: IR Matrixspectroscopic Detection of HAl(Cl)OHAfter photolytical activation of AlCl and H2O in solid argon the molecule HAl(Cl)OH is formed. Structure and bonding is characterized by means of normal coordinate analysis and quantum chemical calculations. The complex AlCl···H2O formed directly after condensation serves as a model system for the stabilisation of aluminium monohalide in a mixture of toluene and ether.
Chemischer Transport fester Lösungen. 27. Mischphasenbildung und chemischer Transport im System ZnSe/GaAs
Authors: Brünig C. , Locmelis S. , Milke E. , Binnewies M. 
Published: May 2006

AbstractChemical Vapor Transport of Solid Solutions. 27. Formation of Solid Solutions and Chemical Vapor Transport in the System GaAs/ZnSeThe miscibility of ZnSe and GaAs as a function of temperature has been investigated. At temperatures above 1100 °C GaAs and ZnSe form out a continous crystalline solid solution. The phase diagram of this system is presented. Mixed crystals in the system GaAs/ZnSe can be prepared by means of chemical vapor transport using iodine as transport agent. Mass spectrometric investigations have shown the formation of AsSeI(g), an up to now unknown triatomic molecule. First approximate thermodynamic Data for AsSeI(g) are given. The knowledge of AsSeI and its thermodynamic stability is necessary to understand the transport phenomena.