bluuebunny/crossref_metadata_2025 huggingface dataset:
Preparation and characterization of biaxially oriented polypropylene film with high molecular orientation in the machine direction by sequential biaxial stretching
Authors: Masuda Jun'ichi , Ohkura Masatoshi
Published: September 2007

Novel approach of applying the ternary polymer blend of long‐chain branched polypropylene (LCB‐PP), conventional polypropylene (PP), and hydrogenated polydicyclopentadiene (hDCPD) has been employed to tensilize biaxially oriented polypropylene (BOPP) film in the machine direction (MD) by successive sequential biaxial stretching method. It is found that the addition of LCB‐PP improves the MD stretchability of the BOPP film of PP/hDCPD blend. Depending on the content of LCB‐PP, LCB‐PP/PP/hDCPD ternary blend could be biaxially stretched up to the MD stretching ratio (MDX) of 12 without film breakage whereas that of PP (conventional BOPP film) resulted in the MDX up to 6. This excellent MD stretchability enabled to tensilize the BOPP film in the MD, where Young's modulus in the MD could be increased up to 4.9 GPa, twice higher than that of conventional BOPP film. The orientation of total molecular chains and that of crystalline molecular chains were evaluated by in‐plane distribution of refractive indices and wide‐angle X‐ray diffraction, respectively. The results are discussed from the viewpoint of deformation behavior during stretching process. Moreover, the resultant film had a dimensional stability substantially equivalent to that of conventional one, in spite of the higher stretching ratio, and an improved moisture barrier property. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Impacts of coating with various varnishes after impregnation with boron compounds on the combustion properties of Uludag fir
Authors: Atar Musa , Keskin Hakan
Published: September 2007

This study was performed to determine the effects of varnishing after impregnation with boron compounds on combustion properties of Uludag Fir. For this purpose, the test samples prepared from Uludag fir (Abies Bornmülleriana Mattf.) wood were impregnated according to ASTM D 1413‐99 with boric acid (Ba) and borax (Bx) by vacuum technique. After impregnation, surfaces were coated by cellulosic (Cv), synthetic (Sn), polyurethane (Pu), waterborne (Wb), acrylic (Ac), and acid hardening (Ah) varnishes in accordance to ASTM D 3023. Combustion properties of samples after varnishing process were determined according to ASTM E 160‐50. According to material and process type, combustion temperature was highest in without flame source combustion (WFSC), Bx, and Wb but the lowest in flame source combustion (FSC), Ba, and Pu. For the combination of combustion type, impregnation material and varnish type, combustion temperature was the highest in WFSC + Ba + Wb combination but the lowest in WFSC + Ba + Cv combination. Consequently, the tested varnishes showed an increasing impact but boron compounds (Ba and Bx) showed a decreasing impact on combustion properties of Uludag fir wood. In consequence, for usage areas having a high risk of fire, impregnation of wood material with boron compounds before varnishing will decrease combustion temperature and provide security. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Structure and properties of blend fibers prepared from alginate and konjac glucomannan
Authors: Fan Lihong , Zhu Huibin , Zheng Hua , Xu Yongmei , Zhang Chaocan
Published: September 2007

Alginate/konjac glucomannan (KGM) blend fibers, prepared by spinning their mixture solution through a viscose‐type spinneret into a coagulating bath containing aqueous CaCl2 and ethanol, were studied for structure and properties with the aid of infrared spectroscopy and scanning electron micrography. The analyses indicated a good miscibility between alginate and KGM because of the strong interaction. The dry tensile strength of the blend fiber increased with increase in KGM content. The wet tensile strength of fibers decreased with increase in KGM content. The optimal breaking elongations in dry and wet state were obtained when the KGM contents were 30 and 10 wt %, respectively. The most obvious change is that the introduction of KGM in the blend fiber can dramatically improve water‐retention properties of blend fiber compared with pure alginate fiber. The fibers treated with aqueous solution of silver nitrate have good antibacterial activity to Staphylococcus aureus. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Electrical conductivity and mechanical properties of polyaniline/natural rubber composite fibers
Authors: Sukitpaneenit Panu , Thanpitcha Tuspon , Sirivat Anuvat , Weder Christoph , Rujiravanit Ratana
Published: September 2007

Electrically conducting elastomer fibers based on natural rubber (NR) and up to 10% w/w polyaniline (PANI) in its emeraldine base (EB) form were fabricated by a wet spinning process. The resulting fibers at various PANI contents were doped by immersion in aqueous HCl solution, which converted the PANI to the electrically conductive emeraldine salt (ES) form. The morphology of the composite fibers was studied by scanning electron microscopy (SEM). PANI particles were inhomogeneously distributed in the NR matrix. The electrical conductivity of the fibers increased with the increasing PANI‐ES content and leveled off at a value of around 10−3 S/cm at PANI‐ES concentration of 5% w/w. The fibers retained most of their elasticity upon doping, while the tenacity was somewhat reduced. Gratifyingly, the electrical conductivity of the new elastomer fibers was preserved upon elongational deformation, even if strains as large as 600% were applied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007
Egghe's construction of Lorenz curves resolved
Authors: Burrell Quentin L.
Published: September 2007

In a recent article (Burrell, 2006), the author pointed out that the version of Lorenz concentration theory presented by Egghe (2005a, 2005b) does not conform to the classical statistical/econometric approach. Rousseau (2007) asserts confusion on our part and a failure to grasp Egghe's construction, even though we simply reported what Egghe stated. Here the author shows that Egghe's construction rather than “including the standard case,” as claimed by Rousseau, actually leads to the Leimkuhler curve of the dual function, in the sense of Egghe. (Note that here we distinguish between the Lorenz curve, a convex form arising from ranking from smallest to largest, and the Leimkuhler curve, a concave form arising from ranking from largest to smallest. The two presentations are equivalent. See Burrell, 1991, 2005; Rousseau, 2007.)
Adaptive technology for e‐learning: principles and case studies of an emerging field
Authors: Scalise Kathleen , Bernbaum Diana J. , Timms Mike , Harrell S. Veeragoudar , Burmester Kristen , Kennedy Cathleen A. , Wilson Mark
Published: September 2007

This article discusses the rapidly emerging field of computer‐based assessment for adaptive content in e‐learning (National Research Council, 2001), which we call differentiated e‐learning. In e‐learning products, a variety of assessment approaches are being used for such diverse purposes as adaptive delivery of content, individualizing learning materials, dynamic feedback, cognitive diagnosis, score reporting, and course placement (Gifford, 2001). A recent paper at the General Teaching Council Conference in London, England, on teaching, learning, and accountability described assessment for personalized learning through e‐learning products as a “quiet revolution” taking place in education (Hopkins, 2004). In our study, we examine approaches for the use of assessment evidence in e‐learning in four case studies. The products in the case studies were selected for exhibiting at least one exemplary aspect regarding assessment and measurement. The principles of the Berkeley Evaluation & Assessment Research Center Assessment System (Wilson & Sloane, 2000) are used as a framework of analysis for these products with respect to key measurement principles.
Extended Architectures Constructed from Sandwich Tetra‐Metal‐Substituted Polyoxotungstates and Transition‐Metal Complexes
Authors: Zheng Shou‐Tian , Wang Ming‐Hui , Yang Guo‐Yu
Published: September 2007

Three unprecedented 2D architectures made up of sandwich‐type tetra‐metal‐substituted polyoxotungstates and transition‐metal complexes, [Cu(dien)(H2O)]2{[Cu(dien)(H2O)]2‐[Cu(dien)(H2O)2]2[Cu4(SiW9O34)2]}⋅ 5H2O (1; dien=diethylenetriamine), [Zn(enMe)2(H2O)]2{[Zn(enMe)2]2[Zn4‐ (HenMe)2(PW9O34)2]}⋅8H2O (2; enMe =1,2‐diaminopropane), and [Zn(enMe)2‐(H2O)]4[Zn(enMe)2]2{(enMe)2{[Zn‐ (enMe)2]2[Zn4(HSiW9O34)2]}{[Zn‐ (enMe)2(H2O)]2[Zn4(HSiW9O34)2]}}⋅ 13H2O (3) were hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single‐crystal X‐ray diffraction. Compound 1 consists of anions [Cu4(SiW9O34)2]12− linked by copper complexes into a 2D structure, whereas 2 is constructed from novel inorganic–organic hybrid anions [Zn4(HenMe)2(PW9O34)2]8− linked by zinc complexes into a 2D structure. The most interesting is the unique 2D network 3, which consists of anions [Zn4(PW9O34)2]10− with two types of bridging groups: zinc complexes and enMe ligands.
Spectrum–Structure Relationship in Carbohydrate Vibrational Circular Dichroism and Its Application to Glycoconjugates
Authors: Taniguchi Tohru , Monde Kenji
Published: September 2007

Preliminary reports of the nature of the vibrational circular dichroism (VCD) peak at around 1145 cm−1, which is characteristic of axial glycosidic sugars and is called the glycoside band (J. Am. Chem. Soc. 2004, 126, 9496), have been throughly examined. Through systematic carbohydrate measurements, it was found that the sign of the glycoside band reflects not only the anomeric configuration but also the pyranose conformation. Isotope and theoretical studies characterized its vibrational mode as C1–H1 deformation coupled with C1–O1 stretching, which indicates its applicability to more‐complicated glycoconjugates. In this study, for the first time, carbohydrate VCD spectra were reliably predicted by means of density functional theory (DFT) calculations. The VCD technique was applied to glycopeptides, and simultaneous analysis of both the carbohydrate and aglycan parts was carried out.
Simultaneous saccharification and fermentation of steam‐pretreated bagasse using Saccharomyces cerevisiae TMB3400 and Pichia stipitis CBS6054
Authors: Rudolf Andreas , Baudel Henrique , Zacchi Guido , Hahn‐Hägerdal Bärbel , Lidén Gunnar
Published: September 2007

Sugarcane bagasse—a residue from sugar and ethanol production from sugar cane—is a potential raw material for lignocellulosic ethanol production. This material is high in xylan content. A prerequisite for bioethanol production from bagasse is therefore that xylose is efficiently fermented to ethanol. In the current study, ethanolic fermentation of steam‐pretreated sugarcane bagasse was assessed in a simultaneous saccharification and fermentation (SSF) set‐up using either Saccharomyces cerevisiae TMB3400, a recombinant xylose utilizing yeast strain, or Pichia stipitis CBS6054, a naturally xylose utilizing yeast strain. Commercial cellulolytic enzymes were used and the content of water insoluble solids (WIS) was 5% or 7.5%. S. cerevisiae TMB3400 consumed all glucose and large fraction of the xylose in SSF. Almost complete xylose conversion could be achieved at 5% WIS and 32°C. Fermentation did not occur with P. stipitis CBS6054 at pH 5.0. However, at pH 6.0, complete glucose conversion and high xylose conversion (>70%) was obtained. Microaeration was required for P. stipitis CBS6054. This was not necessary for S. cerevisiae TMB3400. Biotechnol. Bioeng. 2008;99: 783–790. © 2007 Wiley Periodicals, Inc.
The ATP‐Binding Site of Protein Kinase CK2 Holds a Positive Electrostatic Area and Conserved Water Molecules
Authors: Battistutta Roberto , Mazzorana Marco , Cendron Laura , Bortolato Andrea , Sarno Stefania , Kazimierczuk Zygmunt , Zanotti Giuseppe , Moro Stefano , Pinna Lorenzo A.
Published: September 2007

CK2 is a highly pleiotropic Ser/Thr protein kinase that is able to promote cell survival and enhance the tumour phenotype under specific circumstances. We have determined the crystal structure of three new complexes with tetrabromobenzimidazole derivatives that display Ki values between 0.15 and 0.30 μM. A comparative analysis of these data with those of four other inhibitors of the same family revealed the presence of some highly conserved water molecules in the ATP‐binding site. These waters reside near Lys68, in an area with a positive electrostatic potential that is able to attract and orient negatively charged ligands. The presence of this positive region and two unique bulky residues that are typical of CK2, Ile66 and Ile174, play a critical role in determining the ligand orientation and binding selectivity.
Location of the Hole and Acid Proton in Neutral Nonprotonated and Protonated Mixed (Phthalocyaninato)(porphyrinato) Yttrium Double‐Decker Complexes: Density Functional Theory Calculations
Authors: Zhang Yuexing , Cai Xue , Yao Ping , Xu Hui , Bian Yongzhong , Jiang Jianzhuang
Published: September 2007

The location of the hole and acid proton in neutral nonprotonated and protonated mixed (phthalocyaninato)(porphyrinato) yttrium double‐decker complexes, respectively, is studied on the basis of density functional theory (DFT) calculations on the molecular structures, molecular orbitals, atomic charges, and electronic absorption and infrared spectra of the neutral, reduced, and two possible protonated species of a mixed (phthalocyaninato)(porphyrinato) yttrium compound: [(Pc)Y(Por)], [(Pc)Y(Por)]−, [(HPc)Y(Por)], and [(Pc)Y(HPor)], respectively. When the neutral [(Pc)Y(Por)] is reduced to [(Pc)Y(Por)]−, the calculated results on the molecular structure, atomic charge, and electronic absorption and infrared spectra show that the added electron has more influence on the Pc ring than on its Por counterpart, suggesting that the location of the hole is on the Pc ring in neutral [(Pc)Y(Por)]. Nevertheless, comparison of the calculation results on the structure, orbital composition, charge distribution, and electronic absorption and infrared spectra between [(HPc)Y(Por)] and [(Pc)Y(HPor)] leads to the conclusion that the acid proton in the protonated mixed (phthalocyaninato)(porphyrinato) yttrium compound should be localized on the Por ring rather than the Pc ring, despite the localization of the hole on the Pc ring in [(Pc)Y(Por)]. This result is in line with the trend revealed by comparative studies of the X‐ray single‐crystal molecular structures between [MIII{Pc(α‐OC5H11)4}(TClPP)] and [MIIIH{Pc(α‐OC5H11)4}(TClPP)] (H2TClPP=5,10,15,20‐tetrakis(4‐chlorophenyl)porphyrin; M=Sm, Eu). The present work not only represents the first systemic DFT study on the structures and properties of mixed (phthalocyaninato)(porphyrinato) yttrium double‐decker complexes, but more importantly sheds further light on the nature of protonated bis(tetrapyrrole) rare‐earth complexes.
Chameleon Reactivity of the Allene Bond of 4‐Vinylidene‐2‐oxazolidinone: Novel Through‐Space Conjugative Nucleophilic Addition of Electron‐Rich Alkenes and Hetero‐Nucleophiles
Authors: Kimura Masanari , Horino Yoshikazu , Mori Masahiko , Tamaru Yoshinao
Published: September 2007

The CαCβ double bond of allene carbamates 1 serves as an electron acceptor similar to the double bond of conjugated enones by means of a through‐space interaction with the NSO2 bond; the carbamate double bond is thus subject to nucleophilic addition for a wide variety of nucleophiles, which proceeds under mild conditions by heating at 70–100 °C. Depending on the kind of nucleophiles, 1 displays three different reaction modes: 1) Typically enol ethers and allylsilanes promote 1,3‐sulfonyl migration of 1 and undergo the inverse electron demand Diels–Alder reaction with the 1‐aza‐1,3‐butadiene intermediates II thus formed to furnish bicyclic 2‐alkoxy‐5‐sulfonyltetrahydropyridines 2 and 2‐silylmethyl‐5‐sulfonyltetrahydropyridines 3, respectively, with high regio‐ and stereoselectivity and retention of configuration of the double bonds of these electron‐rich alkenes; 2) silanes (RnSiH4−n, n=1–3) and thiols deliver the hydride and the thiolate at the Cβ carbon and promote the 1,3‐sulfonyl migration, followed by protonation of the thus‐formed carbamate anion (Z)‐III to provide, for example, (Z)‐4 a and (Z)‐4 j, respectively; 3) alcohols simply add to the CαCβ double bond and provide (E)‐6. Usually, the reaction with alcohols is accompanied by the second pathway, giving rise to, for example, (Z)‐4 b in addition to (E)‐6 b. Phenol engages in the third pathway and provides (E)‐6 g exclusively. Heteroaromatics, such as furans and benzofurans follow the first pathway, however, in a different regioselectivity from enol ethers and allylsilanes, delivering the oxygen atom at the 3‐position of 5‐sulfonyltetrahydropyridines (2 g and 2 h). Indoles, on the other hand, show a dichotomy, equally enjoying the first and the third pathways and provide mixtures of (E)‐7 and (E)‐8, respectively.
Suppression of background gradients in (B0 gradient‐based) NMR diffusion experiments
Authors: Zheng Gang , Price William S.
Published: September 2007

Artifacts arising from background gradients are very common in NMR diffusion (i.e., PGSE) experiments involving B0 gradients because of the unavoidable magnetic susceptibility differences and B0 inhomogeneity within and around the sample. This article presents the general methodology to develop PGSE sequences with background gradient suppression. Most of the available methods which can be used for the suppression of the effects of background gradients are discussed. And two newly developed methods are presented in detail: frequency analysis of spin‐dephasing, which assumes the artifacts due to background gradients come from the resonance between the spin‐dephasing caused by applied gradients and background gradients, and asymmetric bipolar stimulated‐echo‐based PGSE, which can suppress the effects of nonconstant background gradients. © 2007 Wiley Periodicals, Inc.Concepts Magn Reson Part A 30A: 261–277, 2007.
Experimental realization of electromagnetically induced transparency in liquid‐state NMR
Authors: Fernandes Louis E. , Choy Jennifer T. , Khanal Devesh R. , Cory David G.
Published: September 2007

Quantum interference effects are physical manifestations of the laws of quantum mechanics and provide a tangible link between the microscopic quantum mechanical domain and the macroscopic world that we observe. These phenomena deviate greatly from classical expectations and can be difficult to understand without experimental demonstrations. Here, we suggest an illustrative and accessible means to observe and understand a purely quantum interference effect, electromagnetically induced transparency (EIT), by viewing it from the perspective of quantum information processing (QIP). We also show that NMR, with its accessibility and ability to create pseudo‐pure states suitable for qubit manipulation, is an ideal tool for EIT. This article provides a description of EIT in QIP terms, as well as an experimental demonstration of this effect on an NMR spectrometer. © 2007 Wiley Periodicals, Inc.Concepts Magn Reson Part A 30A: 236–245, 2007.
Progress in the treatment of acute myeloid leukemia
Authors: Ravandi Farhad , Burnett Alan K. , Agura Edward D. , Kantarjian Hagop M.
Published: September 2007

Significant progress in understanding the mechanisms leading to the development of acute myeloid leukemia (AML) has led to the identification of numerous molecular abnormalities that may be responsible for leukemogenesis. Over the same period, large trials have established standard regimens combining cytotoxic agents for the treatment of patients with AML. Current research is attempting to better stratify patients by identifying risk factors responsible for resistance, and to discern ways for incorporating newer agents with specific and targeted activity into our standard regimens, Herein the recent developments in the diagnosis and treatment of AML are reviewed. Cancer 2007. © 2007 American Cancer Society.
Coherent anti‐Stokes Raman Scattering Microscopy
Authors: Müller Michiel , Zumbusch Andreas
Published: September 2007

Coherent anti‐Stokes Raman scattering (CARS) microscopy is presented as a new nonlinear optical technique. The combination of vibrational spectroscopy and microscopy allows highly sensitive investigations of unlabelled samples. CARS is an ideal tool for studying a broad variety of samples. The main drawback of the technique is its non‐zero‐background nature, which implies that the signal has to be detected against a nonresonant background. The need to solve this problem is reflected in the rapid technological developments that have been observed during the last decade. Recent results show that CARS microscopy has the potential to become an important complementary technique that can be used with other well‐established microscopic methods. Although it has some limitations, it offers unique access to many problems that cannot be tackled with conventional techniques. For this reason, it can be expected that the impressive growth of the field will continue.
Das Herkulesbauwerk in Kassel‐Wilhelmshöhe
Authors: Huster Ulrich , Seim Werner
Published: September 2007

Im Jahr 2007 wurde mit der grundlegenden Instandsetzung des Herkulesbauwerks in Kassel‐Wilhelmshöhe begonnen. Die geplanten Baumaßnahmen, die Teil der Aufwertung und Neukonzeptionierung der Kasseler Museumslandschaft sind, wurden durch eine umfassende Recherche zur Bau‐ und Schadensgeschichte sowie durch Erkundungen des Baugefüges und materialtechnologische Untersuchungen vorbereitet. Im vorliegenden Beitrag werden die wichtigsten Ergebnisse dieser Zustandserfassung erläutert; die wichtigsten Maßnahmen der statisch‐konstruktiven Sicherung des Bauwerks werden vorgestellt.
Bestandsmodernisierung und Bestandsersatz – ein Vergleich der Nachhaltigkeit unter besonderer Berücksichtigung von “nachhaltigem Mauerwerk”
Authors: Pfeiffer Martin
Published: September 2007

Die deutsche Gesellschaft, Politik, Wohnungs‐ und Bauwirtschaft verstärken die notwendigen Bemühungen zum nachhaltigen Umgang mit dem baulichen Bestand des Wohnungs‐ und Nichtwohnungsbaus in der Zukunft. Das Bauministerium lässt aktuell zur “Zukunft Bau” und zum “Leitbild Bauwirtschaft” intensiv forschen.
Bemessung von unbewehrtem Mauerwerk nach dem genaueren Verfahren – EC 6 und DIN 1053 im Vergleich
Authors: Jäger Wolfram
Published: September 2007

In dem Beitrag werden der EC 6 und die DIN 1053‐100 gegenübergestellt und verglichen. Auf bestehende Unterschiede wird aufmerksam gemacht. Differenzstandpunkte werden beleuchtet und Begründungen für diese angegeben. Es soll damit eine Basis geschaffen werden, Klärungen und Entscheidungen herbeizuführen.

Mit der in Angriff genommenen Überarbeitung der DIN 1053‐1 bei gleichzeitiger Integration der Konstruktion und Ausführung soll abgesichert werden, dass ein konsensfähiger nationaler Standpunkt zum EC 6 bezogen werden kann und zugleich eine dem neuesten Stand entsprechende Norm bereitsteht, die im Bedarfsfalle der Praxis zur Verfügung gestellt werden kann.

Für die Architekten, Ingenieure und Ausführenden besteht hinsichtlich der Anwendung der DIN 1053‐100 kein Grund zur Beunruhigung. Die jetzt laufenden Normungsaktivitäten haben das Ziel, rechtzeitig vorausschauend zu arbeiten und andererseits aber auch erreichbare Verbesserungen schnell weiterzureichen.
Platinum‐Catalyzed Intermolecular Hydroamination of Alkenes: Halide‐Anion‐Promoted Catalysis
Authors: Brunet Jean‐Jacques , Chu Ngoc‐Chau , Rodriguez‐Zubiri Mireia
Published: September 2007

Tetraalkylphosphonium halides play the role of “promoters” for the previously unknown PtII‐catalyzed hydroamination of alkenes. The promoting effect of these “cocatalysts” depends only upon their anionic moiety. The PtII/nBu4PBr system exhibits an unprecedented catalytic activity (aerobic conditions) for the hydroamination of ethylene and 1‐hexene (regioselectivity > 95 %, Markovnikov).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Intramolecular Hydroaminations Mediated by Reductive Mercuration or n‐Butyllithium To Afford 3‐Methyl‐ and 3,4‐Dimethyl‐1,2,3,4‐tetrahydroisoquinolines
Authors: Pathak Rakhi , Naicker Prevashni , Thompson Warren A. , Fernandes Manuel A. , de Koning Charles B. , van Otterlo Willem A. L.
Published: September 2007

The synthesis of 3‐methyl‐ and 3,4‐dimethyltetrahydroisoquinolines from aromatic aminoalkenes using intramolecular hydroamination reactions is described. This reaction was achieved by way of a reductive aminomercuration using mercuric acetate followed by sodium borohydride, or by using sub‐stoichiometric amounts of n‐butyllithium. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Glucose Biosensors Based on Electrodes Modified with Ferrocene Derivatives Intercalated into Mg/Al Layered Double Hydroxides
Authors: Colombari M. , Ballarin B. , Carpani I. , Guadagnini L. , Mignani A. , Scavetta E. , Tonelli D.
Published: September 2007

Two amperometric biosensors based on glassy carbon electrodes (GC) modified with Mg/Al layered double hydroxides (LDHs) containing ferrocene‐carboxylate (FcCO2H) or ferrocene‐sulfonate (FcSO3H), as interlayer anions, and glucose oxidase (GOx) are presented. Amperometric detection of glucose involves the electrochemical oxidation of H2O2 mediated by the ferrocene derivative. Optimization of the biosensors construction and of the operative conditions was investigated and is discussed herein. The performances of the two biosensors were evaluated by chronoamperometry, working at low anodic potentials (+0.400 V for FcCO2H and +0.500 V for FcSO3H vs. SCE). The linearity extended up to 1.5 mM and 10.0 mM in batch and in flow conditions, respectively, for both biosensors, whereas the sensitivity was higher for the one based on FcCO2H (4.8±0.3 versus 2.0±0.3 μA mM−1cm−2 in batch mode, and 63.9±0.4 versus 25.8±0.4 μA mM−1cm−2 in flow mode). The biosensors display rapid response time (less than 20 s), good reproducibility, as well as good operational stability. Glucose can be accurately determined in the presence of the most common interferences that coexist in blood serum if an oxidative membrane containing nanoparticles of MnO2 is applied on the biosensors' surface.
Voltammetric Behavior of p‐Nitrophenol and Its Trace Determination in Human Urine by Liquid Chromatography with a Dual Reductive Mode Electrochemical Detection System
Authors: Honeychurch Kevin C. , Hart John P.
Published: September 2007

The determination of trace p‐nitrophenol (PNP) concentrations in human urine has been successfully achieved by high performance liquid chromatography dual electrode detection (LC‐DED) in the reduction‐reduction mode. Initial cyclic voltammetric studies were undertaken to investigate the electrochemical behavior of PNP at a glassy carbon electrode over a wide pH range; the redox processes giving rise to the signals have been deduced. Further, deductions regarding the behavior in the flow cells were made from hydrodynamic voltammetric data. PNP eluting from the analytical LC column is first reduced to p‐hydroxylaminophenol, at the first generator electrochemical cell. This species then undergoes chemical oxidation to give a quinoneimine species which is then detected at the downstream detector electrode using an applied potential of −0.1 V. The optimum chromatographic mobile phase consisted of 40% acetonitrile, 60% water, containing 25 mM o‐phosphoric acid, at a flow rate of 0.5 mL/min; this was used in conjunction with a Hypersil C18 column. Hydrodynamic voltammetric studies were undertaken to investigate the dual electrode behavior of PNP, and an applied potential of −2.0 V at the generator cell and −0.10 V at the detector cell were found to be optimum. The response was found to be linear over the range 7.0 ng to 500 ng on column, with an associated R2 value of 0.9981; the limit of detection was found to be 1.0 ng PNP on column. No interferences were seen for a number of common drugs or for the principal electrochemically active components of human urine or serum. The developed assay was successfully applied to the determination of trace concentrations of PNP in human urine samples, exhibiting coefficients of variation of 7.1% (n=7), with a mean recovery of 94.7% for urine fortified at 522 ng mL−1.
Serological Diagnosis of Tularemia in Mice Using the Amperometric Immunosensor
Authors: Pohanka Miroslav , Skládal Petr
Published: September 2007

Tularemia caused by the bacterium Francisella tularensis belongs to danger infective diseases, therefore timely diagnosis is an important part of protective activities. A novel approach for serological diagnostics of tularemia using a four‐channel amperometric immunosensor was proposed and evaluated on BALB/c mice as a model organism. The immunosensor was able to work with small volumes of serum samples (0.05 μL per assay) and diagnosed tularemic infection very early after immunization. From the 5th day, it was possible to distinguish tularemic sera from control sera from mice immunized with Escherichia coli on the probability level of 0.99 (t‐test). Some 40 measurements per one hour can be realized with the developed procedure. The obtained results were confirmed by the standard indirect ELISA. The proposed immunosensor‐based approach seems promising for rapid detection of microbial pathogen infections.
Determination of caffeine in coffee products by dynamic complexation with 3,4‐dimethoxycinnamate and separation by CZE
Authors: Nogueira Thiago , do Lago Claudimir Lucio
Published: September 2007

A method based on the formation of π‐complexes with chlorogenate‐like species was proposed for the determination of caffeine in regular (nondecaffeinated) and decaffeinated coffee. Both caffeate and 3,4‐dimethoxycinnamate were able to transform caffeine – a neutral species in aqueous solutions – into an anionic species. The usage of 3,4‐dimethoxycinnamate in the running electrolyte is advantageous, because of its greater chemical stability and the improved resolution of the peaks of caffeine, theobromine, and theophylline. Negative peaks were registered with a capacitively coupled contactless conductivity detector when solutions of these alkylxanthines were analyzed with a BGE composed of 20 mmol/L 3,4‐dimethoxycinnamic acid and pH adjusted to 8.5 with Tris. This behavior was expected, because the complex is larger and thus should move slower than the free anion. Caffeine was determined in ground and instant coffee with precision and accuracy that meet Brazilian norms about such products. The LOD was estimated as 33 mg/L, which corresponds to 0.8 and 0.3 mg of caffeine per gram of dry instant coffee and ground coffee, respectively. For the case of decaffeinated coffee, ten times preconcentration with dichloromethane was carried out to allow the quantitation of caffeine, which should not exceed the concentration of 1 mg/g in dry matter.
Epigenetic aspects of genotoxic and non‐genotoxic hepatocarcinogenesis: Studies in rodents
Authors: Pogribny Igor P. , Rusyn Ivan , Beland Frederick A.
Published: September 2007

Hepatocellular carcinoma, which is one of the most prevalent life‐threatening human cancers, is showing an increased incidence worldwide. Recent evidence indicates that the development of hepatocellular carcinoma is associated with not only genetic alterations, but also with profound epigenetic changes. This review summarizes the current knowledge about epigenetic alterations during rodent hepatocarcinogenesis, considers the similarities and differences in epigenetic effects of genotoxic and non‐genotoxic rodent liver carcinogens, and discusses the possible role of these effects in the causality of liver tumor development. Environ. Mol. Mutagen., 2008. Published 2007 Wiley‐Liss, Inc.
Influence of heat and moisture exchanger respiratory load on transcutaneous oxygenation in laryngectomized individuals: A randomized crossover study
Authors: Zuur J. Karel , Muller Sara H. , Sinaasappel Michiel , Hart Guus A. M. , van Zandwijk Nico , Hilgers Frans J. M.
Published: September 2007

Background

High‐resistance heat and moisture exchangers (HMEs) have been reported to increase transcutaneous oxygenation (tcpO2) values in laryngectomized individuals and to negatively influence patient compliance. The goal of the present study was to validate earlier published results on short‐term transcutaneous oxygenation changes by high‐resistance HMEs.

Methods

We conducted a randomized crossover study, monitoring the influence of an HME on tcpO2 over a 2‐hour time interval in 20 subjects.

Results

No evidence of an immediate HME effect (95% CI: −14.9–13.3 mm Hg, p = .91), or a time‐dependent HME effect (95% CI: −.121 – .172 mm Hg/minute, p = .74), on tcpO2 was found. After fitting the statistical model without time dependency, again no evidence of HME presence was seen (95% CI: −.5 mm Hg – 3.6 mm Hg, p = .15).

Conclusion

In contrast to earlier suggestions, there is no evidence of increased tcpO2 levels by high‐resistance HMEs in laryngectomized individuals. Thus, using such HMEs has no added clinical value in this respect. © 2007 Wiley Periodicals, Inc. Head Neck, 2007
Effects of substance P on memory and mood in healthy male subjects
Authors: Herpfer Inga , Katzev Michael , Feige Bernd , Fiebich Bernd L. , Voderholzer Ulrich , Lieb Klaus
Published: September 2007

There is evidence from human and animal studies that substance P (SP) is involved in the etiopathology of depression and anxiety. Furthermore, animal studies have shown effects of SP on memory. In a double‐blind, randomized cross‐over study, 13 healthy young men received SP (1.5 pmol/kg/min) or placebo (NaCl) intravenously over 90 min at two different days. Before and during the infusion, symptoms of anxiety and depression were assessed by different self‐rating questionnaires and cognitive functioning by the Auditory‐Verbal Learning Test (AVLT) as well as by two subtests of the Test for Attentional Performance (TAP). Infusion of SP caused an increase of symptoms of inner tension and of anxiety as assessed by the Acute Panic Inventory (API) and a disturbance of short‐term memory in the AVLT. The results may be interpreted as evidence for an anxiogenic and memory‐disturbing effect of SP. Further studies will focus on the effects of SP in patients with depression, anxiety and cognitive disorders. Copyright © 2007 John Wiley & Sons, Ltd.
Monitoring urban impacts on suspended sediment, trace element, and nutrient fluxes within the City of Atlanta, Georgia, USA: program design, methodological considerations, and initial results
Authors: Horowitz Arthur J. , Elrick Kent A. , Smith James J.
Published: September 2007

Atlanta, Georgia (City of Atlanta, COA), is one of the most rapidly growing urban areas in the US. Beginning in 2003, the US Geological Survey established a long‐term water‐quantity/quality monitoring network for the COA. The results obtained during the first 2 years have provided insights into the requirements needed to determine the extent of urban impacts on water quality, especially in terms of estimating the annual fluxes of suspended sediment, trace/major elements, and nutrients.

During 2004/2005, suspended sediment fluxes from the City of Atlanta (COA) amounted to about 150 000 t year−1; ≥ 94% of the transport occurred in conjunction with storm‐flow, which also accounted for ≥ 65% of the annual discharge. Typically, storm‐flow averaged ≤20% of the year. Normally, annual suspended sediment fluxes are determined by summing daily loads based on a single calculation step using mean‐daily discharge and a single rating curve‐derived suspended sediment concentration. Due to the small and ‘flashy’ nature of the COAs streams, this approach could produce underestimates ranging from 25% to 64%. Accurate estimates ( ± 15%) require calculation time‐steps as short as every 2–3 h.

Based on annual median base‐flow/storm‐flow chemical concentrations, the annual fluxes of ≥ 75% of trace elements (e.g. Cu, Pb, Zn), major elements (e.g. Fe, Al), and total P occur in association with suspended sediment; in turn, ≥ 90% of the transport of these constituents occur in conjunction with storm‐flow. As such, base‐flow sediment‐associated and dissolved contributions represent relatively insignificant portions of the total annual load. An exception is total N, whose sediment‐associated fluxes range from 50% to 60%; even so, storm‐related transport typically exceeds 80%. Hence, in urban environments, non‐point‐sources appear to be the dominant contributors to the fluxes of these constituents. Published in 2007by John Wiley & Sons, Ltd.
The US treasury market in August 1998: untangling the effects of Hong Kong and Russia with high‐frequency data
Authors: Dungey Mardi , Goodhart Charles , Tambakis Demosthenes
Published: September 2007

The second half of August 1998 was dominated by two events. From 14 to 28 August, the Hong Kong Monetary Authority (HKMA) intervened in Hong Kong equity markets to prevent a speculative double play against their currency board. On 17 August, Russia announced its default on sovereign bonds. This paper demonstrates that the HKMA interventions had a substantial impact on the outcomes for US Treasury markets during this period using a careful analysis of high‐frequency bond market data. On this evidence the shocks emanating from Hong Kong provided liquidity to the US Treasury market when it was most needed. Copyright © 2007 John Wiley & Sons, Ltd.
Insights into nuclear localization and dynamic association of CD38 in Raji and K562 cells
Authors: Trubiani Oriana , Guarnieri Simone , Eleuterio Enrica , Di Giuseppe Fabrizio , Orciani Monia , Angelucci Stefania , Di Primio Roberto
Published: September 2007

CD38 is a type II transmembrane glycoprotein found mainly on the plasma membrane involved in the metabolism of cADPR and NAADP, two nucleotides with calcium mobilizing activity independent of inositol trisphosphate. Recent data report the presence of CD38 in different cellular compartments raising new questions about its effective role in cellular metabolism. In rat hepatocyte nuclei, CD38 has been proposed as a responsive to cADPR integral inner membrane protein suggesting that the nuclear envelope may also be an important source of Ca2+ stores. Further reports indicating that CD38 is localized in nuclear compartments in a variety of cell types and tissues including brain, liver, eye, spleen, and bone raise the condition of resolving the question concerning the effective presence of CD38 within the nucleus. Here we report data supporting the presence of CD38 at nuclear level independently of expression of surface CD38. We utilized two different human leukemia cell lines expressing or not expressing CD38 molecule on their cell surface. The morphological and biochemical results including enzymatic activity and proteomic determinations explain the effective nuclear localization of CD38 in human Raji and K562 cells. Since cell nucleus is a complex and highly dynamic environment with many functionally specialized regions, the nuclear localization of specific proteins represents an important mechanism in signal transduction. The presence of CD38 at the interchromatin region whether linked to nuclear scaffold or stored in nuclear structures as micronuclei and Cajal bodies co‐localizing with coilin, suggests its involvement in nuclear processes including transcription, replication, repairing and splicing. J. Cell. Biochem. 103: 1294–1308, 2008. © 2007 Wiley‐Liss, Inc.
Cloning and characterisation of Ifi206: A new murine HIN‐200 family member
Authors: Ludlow Louise E. , Hii Linda L. , Thorpe Janine , Newbold Andrea , Tainton Kellie M. , Trapani Joseph A. , Clarke Christopher J.P. , Johnstone Ricky W.
Published: September 2007

HIN‐200 proteins are interferon‐inducible proteins capable of regulating cell growth, senescence, differentiation and death. Using a combination of in silico analysis of NCBI EST databases and screening of murine C57BL/6 cDNA libraries we isolated novel murine HIN‐200 cDNAs designated Ifi206S and Ifi206L encoding two putative mRNA splice variants. The p206S and p206L protein isoforms have a modular domain structure consisting of an N‐terminal PAAD/DAPIN/Pyrin domain, a region rich in serine, threonine and proline residues and a C‐terminal 200 B domain characteristic of other HIN‐200 proteins. Ifi206 mRNA was detected only in the spleen and lung of BALB/c and C57BL/6 mice and expression was up‐regulated by both types I and II IFN subtypes. p206 protein was predominantly expressed in the cytoplasm and addition of LMB, a CRM1 dependent nuclear export inhibitor, caused p206 to accumulate in the nucleus. Unlike other human and mouse HIN‐200 proteins that contain only a single 200 amino acid domain, overexpression of p206 impaired the clonogenic growth of tumour cell lines. Thus, p206 represents the newest HIN‐200 family member discovered. It has distinct and restricted pattern of expression however maintains many of the hallmarks of HIN‐200 proteins including the presence of a characteristic 200 X domain, induction by interferon and an ability to suppress tumour cell growth. J. Cell. Biochem. 103: 1270–1282, 2008. © 2007 Wiley‐Liss, Inc.
Secretion without Golgi
Authors: Prudovsky Igor , Tarantini Francesca , Landriscina Matteo , Neivandt David , Soldi Raffaella , Kirov Aleksandr , Small Deena , Kathir Karuppanan Muthusamy , Rajalingam Dakshinamurthy , Kumar Thallapuranam Krishnaswamy Suresh
Published: September 2007

A growing number of proteins devoid of signal peptides have been demonstrated to be released through the non‐classical pathways independent of endoplasmic reticulum and Golgi. Among them are two potent proangiogenic cytokines FGF1 and IL1α. Stress‐induced transmembrane translocation of these proteins requires the assembly of copper‐dependent multiprotein release complexes. It involves the interaction of exported proteins with the acidic phospholipids of the inner leaflet of the cell membrane and membrane destabilization. Not only stress, but also thrombin treatment and inhibition of Notch signaling stimulate the export of FGF1. Non‐classical release of FGF1 and IL1α presents a promising target for treatment of cardiovascular, oncologic, and inflammatory disorders. J. Cell. Biochem. 103: 1327–1343, 2008. © 2007 Wiley‐Liss, Inc.
Biochemical analysis of the interaction of calcium with toposome: A major protein component of the sea urchin egg and embryo
Authors: Hayley Michael , Sun Ming , Merschrod S Erika F. , Davis Philip J. , Robinson John J.
Published: September 2007

We have investigated the biochemical and functional properties of toposome, a major protein component of sea urchin eggs and embryos. Atomic force microscopy was utilized to demonstrate that a Ca2+‐driven change in secondary structure facilitated toposome binding to a lipid bilayer. Thermal denaturation studies showed that toposome was dependent upon calcium in a manner paralleling the effect of this cation on secondary and tertiary structure. The calcium‐induced, secondary, and tertiary structural changes had no effect on the chymotryptic cleavage pattern. However, the digestion pattern of toposome bound to phosphatidyl serine liposomes did vary as a function of calcium concentration. We also investigated the interaction of this protein with various metal ions. Calcium, Mg2+, Ba2+, Cd2+, Mn2+, and Fe3+ all bound to toposome. In addition, Cd2+ and Mn2+ displaced Ca2+, prebound to toposome, while Mg2+, Ba2+, and Fe3+ had no effect. Collectively, these results further enhance our understanding of the role of Ca2+ in modulating the biological activity of toposome. J. Cell. Biochem. 103: 1464–1471, 2008. © 2007 Wiley‐Liss, Inc.
Regulation of monocarboxylate transporter 1 (MCT1) promoter by butyrate in human intestinal epithelial cells: Involvement of NF‐κB pathway
Authors: Borthakur Alip , Saksena Seema , Gill Ravinder K. , Alrefai Waddah A. , Ramaswamy Krishnamurthy , Dudeja Pradeep K.
Published: September 2007

Butyrate, a short chain fatty acid (SCFA) produced by bacterial fermentation of undigested carbohydrates in the colon, constitutes the major fuel for colonocytes. We have earlier shown the role of apically localized monocarboxylate transporter isoform 1 (MCT1) in transport of butyrate into human colonic Caco‐2 cells. In an effort to study the regulation of MCT1 gene, we and others have cloned the promoter region of the MCT1 gene and identified cis elements for key transcription factors. A previous study has shown up‐regulation of MCT1 expression, and activity by butyrate in AA/C1 human colonic epithelial cells, however, the detailed mechanisms of this up‐regulation are not known. In this study, we demonstrate that butyrate, a substrate for MCT1, stimulates MCT1 promoter activity in Caco‐2 cells. This effect was dose dependent and specific to butyrate as other predominant SCFAs, acetate, and propionate, were ineffective. Utilizing progressive deletion constructs of the MCT1 promoter, we showed that the putative butyrate responsive elements are in the −229/+91 region of the promoter. Butyrate stimulation of the MCT1 promoter was found to be independent of PKC, PKA, and tyrosine kinases. However, specific inhibitors of the NF‐κB pathway, lactacystein (LC), and caffeic acid phenyl ester (CAPE) significantly reduced the MCT1 promoter stimulation by butyrate. Also, butyrate directly stimulated NF‐κB‐dependent luciferase reporter activity. Histone deacetylase (HDAC) inhibitor trichostatin A (TSA) also stimulated MCT1 promoter activity, however, unlike butyrate, this stimulation was unaltered by the NF‐κB inhibitors. Further, the combined effect of butyrate, and TSA on MCT1 promoter activity was additive, indicating that their mechanisms of action were independent. Our results demonstrate the involvement of NF‐κB pathway in the regulation of MCT1 promoter activity by butyrate. J. Cell. Biochem. 103: 1452–1463, 2008. © 2007 Wiley‐Liss, Inc.
Empirical bond‐order potential for hydrocarbons: Adaptive treatment of van der Waals interactions
Authors: Liu Aibing , Stuart Steven J.
Published: September 2007

Bond‐order potentials provide a powerful class of models for simulating chemically reactive systems with classical potentials. In these models, the covalent bonding interactions adapt to the environment, allowing bond strength to change in response to local chemical changes. However, the non‐bonded interactions should also adapt in response to chemical changes, an effect which is neglected in current bond‐order potentials. Here the AIREBO potential is extended to include adaptive Lennard‐Jones terms, allowing the van der Waals interactions to vary adaptively with the chemical environment. The resulting potential energy surface and its gradient remain continuous, allowing it to be used for dynamics simulations. This new potential is parameterized for hydrocarbons, and is fit to the energetics and densities of a variety of condensed phase molecular hydrocarbons. The resulting model is more accurate for modeling aromatic and other unsaturated hydrocarbon species, for which the original AIREBO potential had some deficiencies. Testing on compounds not used in the fitting procedure shows that the new model performs substantially better in predicting heats of vaporization and pressures (or densities) of condensed‐phase molecular hydrocarbons. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008