bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbohydrate Chain of Ganglioside GM1 as a Ligand: Identification of the Binding Strategies of Three 15 mer Peptides and Their Divergence from the Binding Modes of Growth‐Regulatory Galectin‐1 and Cholera Toxin
Authors: Siebert Hans‐Christian , Born Karin , André Sabine , Frank Martin , Kaltner Herbert , von der Lieth Claus‐Wilhelm , Heck Albert J. R. , Jiménez‐Barbero Jesús , Kopitz Jürgen , Gabius Hans‐Joachim
Published: November 2005

The branched pentasaccharide chain of ganglioside GM1 is a prominent cell surface ligand, for example, for cholera toxin or tumor growth‐regulatory homodimeric galectins. This activity profile via protein recognition prompted us to examine the binding properties of peptides with this specificity. Our study provides insights into the mechanism of molecular interaction of this thus far unexplored size limit of the protein part. We used three pentadecapeptides in a combined approach of mass spectrometry, NMR spectroscopy and molecular modelling to analyze the ligand binding in solution. Availability of charged and hydrophobic functionalities affected the intramolecular flexibility of the peptides differently. Backfolding led to restrictions in two cases; the flexibility was not reduced significantly by association of the ligand in its energetically privileged conformations. Major contributions to the interaction energy arise from the sialic acid moiety contacting Arg/Lys residues and the N‐terminal charge. Considerable involvement of stacking between the monovalent ligand and aromatic rings could not be detected. This carbohydrate binding strategy is similar to how an adenoviral fiber knob targets sialylated glycans. Rational manipulation for an affinity enhancement can now be directed to reduce the flexibility, exploit the potential for stacking and acquire the cross‐linking capacity of the natural lectins by peptide attachment to a suitable scaffold.
Hydrogen Bonding and Dynamic Behaviour in Crystals and Polymorphs of Dicarboxylic–Diamine Adducts: A Comparison between NMR Parameters and X‐ray Diffraction Studies
Authors: Gobetto Roberto , Nervi Carlo , Chierotti Michele R. , Braga Dario , Maini Lucia , Grepioni Fabrizia , Harris Robin K. , Hodgkinson Paul
Published: November 2005

Fumaric, malonic, maleic, and hydromuconic (HOOCCH2(CH)2CH2COOH) acids were used to prepare a series of hydrogen‐bonded adducts or salts, depending on whether acid–base proton transfer takes place, with the dibase [N(μCH2CH2)3N] in various stoichiometric ratios. The resulting compounds have been investigated by using the 1H MAS, 15N, and 13C cross polarisation magic‐angle spinning (CPMAS) methods and discussed in relation to X‐ray diffraction studies to ascertain the nature of the O‐H⋅⋅⋅O, N⋅⋅⋅H‐O, and N+‐H⋅⋅⋅O− hydrogen bonds between the various species. In addition, two polymorphic forms of the malonic compound and a hydrate in the maleic case were examined. We also present the correlations between the chemical shifts of the hydrogen‐bonded protons and those from the proton transfer reaction (acid‐to‐base) with the heavy atom distances. The dynamic behaviour in the solid‐state of the [N(μCH2CH2)3N] adducts with fumaric 2:1, maleic 1:1 hydrate, and hydromuconic acids, and a malonate 2:1 polymorph adduct have been investigated by using variable‐temperature 1H spin–lattice relaxation times. A substantial agreement between the activation energies obtained from fitting the T1 data and the results of potential energy barrier calculations demonstrates that the facile reorientation of the [N(μCH2CH2)3N] molecule occurs in several of the adducts.
Zinc Hydrazides and Alkoxyhydrazides: Organometallic Compounds with Novel Zn4N8, Zn4N6O and Zn4N4O2 Cage Structures
Authors: Jana Surajit , Fröhlich Roland , Mitzel Norbert W.
Published: November 2005

Tetrameric [{RZn(NHNMe2)}4] (R = Me, Et), the first organometallic zinc hydrazides to be described, have been prepared by alkane elimination from dialkylzinc solutions and N,N‐dimethylhydrazine. They were characterised by 1H and 13C NMR and IR spectroscopy, mass spectrometry, elemental analysis and X‐ray crystallography. The compounds form asymmetric aggregates containing the novel Zn4N8 core; tetrahedra of Zn atoms bear the alkyl groups at Zn, with the triangular faces bridged by NHNMe2 substituents. The NH groups are connected to two Zn atoms, and the NMe2 groups to one. Hydrolysis of the compounds with water gives [(RZn)4(OH)(NHNMe2)3] as products, which also were characterised as described above. Higher yields of these hydroxo clusters were achieved in one‐pot syntheses by reaction of dialkylzinc solutions with mixtures of N,N‐dimethylhydrazine and water. They contain Zn4N6O cages, in which one hydroxide in the tetrameric hydrazides described above replaces one NHNMe2 group. Similar products can be prepared with alkoxy instead of hydroxy groups, in analogous one‐pot syntheses with alcohols. Alcoholysis of [EtZn(NHNMe2)]4 with methanol or ethanol gave zinc trishydrazide monoalkoxides, [(EtZn)4(OR)(NHNMe2)3] (R = Me, Et), which have constitutions analogous to the monohydroxides. The organozinc bishydrazide bisalkoxides [(MeZn)4(NHNMe2)2(OEt)2] and [(EtZn)4(NHNMe2)2(OEt)2] were obtained in one‐pot reactions from dialkylzinc solutions with mixtures of the hydrazine and alcohol, and their crystal structures, confirmed by spectroscopic methods in solution, show an unsymmetrical aggregation with the novel Zn4N4O2 cage structure.
Total Synthesis of Phorboxazole B
Authors: Li De‐Run , Zhang Dong‐Hui , Sun Cai‐Yun , Zhang Ji‐Wen , Yang Li , Chen Jian , Liu Bo , Su Ce , Zhou Wei‐Shan , Lin Guo‐Qiang
Published: November 2005

An efficient and highly convergent total synthesis of the potent antitumor agent phorboxazole B has been achieved. The synthetic strategy of this synthesis features: 1) a highly efficient substrate‐controlled hydrogenation to construct the functionalized cis‐tetrahydropyrane unit; 2) iterative crotyl addition to synthesize the segment that contains alternating hydroxyl and methyl substituents; 3) Hg(OAc)2/I2‐induced cyclization to establish the cis‐tetrahydropyrane moiety; 4) 1,3‐asymmetric induction in the Mukaiyama aldol reaction to afford the stereogenic centers at C9 and C3; and 5) the exploration of the Still–Gennari olefination reaction to complete the macrolide ring of phorboxazoloe B.
Nitrogen Fixation under Mild Ambient Conditions: Part I—The Initial Dissociation/Association Step at Molybdenum Triamidoamine Complexes
Authors: Le Guennic Boris , Kirchner Barbara , Reiher Markus
Published: November 2005

In several recent studies Schrock and collaborators demonstrated for the first time how molecular dinitrogen can be catalytically transformed under mild and ambient conditions to ammonia by a molybdenum triamidoamine complex. In this work, we investigate the geometrical and electronic structures involved in this process of dinitrogen activation with quantum chemical methods. Density functional theory (DFT) has been employed to calculate the coordination energies of ammonia and dinitrogen relevant for the dissociation/association step in which ammonia is substituted by dinitrogen. In the DFT calculations the triamidoamine chelate ligand has been modeled by a systematic hierarchy of increasingly complex substituents at the amide nitrogen atoms. The most complex ligand considered is an experimentally known ligand with an HMT=3,5‐(2,4,6‐Me3C6H2)2C6H3 substituent. Several assumptions by Schrock and collaborators on key reaction steps are confirmed by our calculations. Additional information is provided on many species not yet observed experimentally. Particular attention is paid to the role of the charge of the complexes. The investigation demonstrates that dinitrogen coordination is enhanced for the negatively charged metal fragment, that is, coordination is more favorable for the anionic metal fragment than for the neutral species. Coordination of N2 is least favorable for the cationic metal fragment. Furthermore, ammonia abstraction from the cationic complex is energetically unfavorable, while NH3 abstraction is less difficult from the neutral and easily feasible from the anionic low‐spin complex.
An Electrochemical Study of the Interactions Between Trace Metals and Humic Substances in Freshwaters by Anodic Stripping Voltammetry with a Thin Mercury Film Rotating Disk Electrode
Authors: Murimboh Catherine A. , Deng Jianfu , Murimboh John , Guthrie Jeffrey W. , Chakrabarti Chuni L. , Lean David R. S.
Published: November 2005

An improved theoretical approach to Anodic Stripping Voltammetry with a Thin Mercury Film Rotating Disk Electrode for elucidating the nature of the interactions of Pb(II), Cd(II) and Zn(II) with humic substances in model solutions of Laurentian fulvic acid, and of Pb(II), Cd(II), Zn(II) and Cu(II) in freshwaters, is presented. Conditional stability constants of Pb(II), Cd(II) and Zn(II) complexes decreased with the ionic potential (z2/r) and increased with softness of the metal ion, indicating strong affinity of soft, polarizable donor ligands on humic substances for softer metal ions, resulting in an appreciable covalent character in electrostatic bonding between the metals and humic substances.
Development and Characterization of Nickel‐NTA‐Polyaniline Modified Electrodes
Authors: Lori Joseph A. , Morrin Aoife , Killard Anthony J. , Smyth Malcolm R.
Published: November 2005

The engineered addition of hexa‐histidine sequences to biomolecules such as antibody fragments has been found to be an excellent means of purifying these materials. This tagging methodology has also been extended to its use as a tool for immobilization and orientation of antibodies on transducer surfaces. Polyvinyl sulfonate‐doped polyanilne (PANI/PVS) can be used as a mediator in amperometric biosensors. This short communication looks at the effect of nickel chelate materials and nickel chelation on this conducting polymer and evaluates it as a potential surface for the immobilization of his‐tagged biomolecules. N‐nitrilotriacetic acid (NTA) was doped into the electropolymerized PANI/PVS at a screen‐printed carbon paste electrode. The resulting NTA‐PANI/PVS film was shown to have comparable electrochemical properties of polymer without the chelating agent. When Ni2+ was applied to the electrode, the incorporated NTA was found to efficiently chelate the metal ions at the electrode surface.
Electrocatalytic Reduction and Determination of Dissolved Oxygen at a Preanodized Screen‐Printed Carbon Electrode Modified with Palladium Nanoparticles
Authors: Yang Chih‐Chio , Kumar Annamalai Senthil , Zen Jyh‐Myng
Published: November 2005

Efficient and stable electrocatalytic activity for the reduction of O2 at activated screen‐printed carbon electrodes modified with palladium nanoparticles (SPE*‐Pd) was demonstrated in this study. X‐ray photoelectron spectroscopy confirmed the formation of >CO functional group on electrode surface during the preanodization procedure at 2.0 V (vs. Ag/AgCl). The existence of chloride moieties was also identified possibly from the organic binder of carbon ink used in SPE fabrication. Both >CO and chloride functional groups were essential for the excellent stability of the SPE*‐Pd. Electrochemical impedance spectroscopy verified the enhanced kinetic rate of oxygen reduction reaction at the as‐prepared Pd nanoparticles. The SPE*‐Pd showed ca. 250 mV positive shift in peak potential together with twice increase in peak current compared to those observed at a SPE‐Pt. The calibration plot was linear up to 8 ppm of DO with sensitivity and regression coefficient of 4.49 μA/ppm and 0.9936, respectively. The variation coefficient of ipc for 7 DO determinations with O2‐saturated pH 7.4 PBS was 2.1%. Real sample assays for ground and tap waters gave consistent values to those measured by a commercial dissolved oxygen meter.
Methanol Tolerant Oxygen Reduction Catalysts Derived from Electrochemically Pre‐treated Bi2Pt2–yIryO7 Pyrochlores
Authors: Beck N. K. , Steiger B. , Scherer G. G. , Wokaun A.
Published: November 2005

The electrocatalytic activity for oxygen reduction on Bi2Pt2–yIryO7 (y = 0, 0.5, 1, 1.3, 1.4, 1.5, 2) electrodes was examined in 0.5 M H2SO4 in the presence and absence of 0.5 M methanol, using the rotating ring‐disk electrode technique. These pyrochlore electrodes exhibited oxygen reduction activity with an onset potential at ca. 0.2 V vs. Hg/Hg2SO4 only after pre‐treatment of potential cycling between –0.6 and 0.6 V vs. Hg/Hg2SO4. This “activation” of the pyrochlores is initiated by a reduction process that produces Bi0 and Pt0 at potentials located near the negative limit of the potential cycling range. Depending on the amount of pyrochlore used to fabricate the electrodes and the amount of charge passed during the reductive “activation”, a thick layer of a Pt containing material that differs from the pyrochlore structure may be produced. A pre‐treatment of potential cycling between –0.3 and 0.8 V vs. Hg/Hg2SO4 did not “activate” the pyrochlores. The oxygen reduction activity and the methanol oxidation activity of the electrochemically treated pyrochlores increased in the order: Bi2Pt0.5Ir1.5O7 < Bi2Pt0.6Ir1.4O7 < Bi2Pt0.7Ir1.3O7 < Bi2PtIrO7 < Bi2Pt1.5Ir0.5O7 < Bi2Pt2O7. Electrochemically treated Bi2Ir2O7 exhibited no catalytic activity.
Alternative Catalysts and Carbon Support Material for PEMFC
Authors: Wikander K. , Ekström H. , Palmqvist A. E. C. , Lundblad A. , Holmberg K. , Lindbergh G.
Published: November 2005

In order to investigate the possibility of increasing the reactivity for oxygen reduction reaction (ORR) of the cathode in a PEMFC a series of Pt/C catalysts was prepared using water‐in‐oil microemulsions for synthesizing Pt nanoparticles. The Pt nanoparticles were deposited on porous carbon support (Vulcan XC‐72 or a mesoporous carbon) and the catalysts were processed into MEAs. The MEA samples were evaluated and compared with a commercial sample and with Pt/C catalyst samples prepared using a conventional direct impregnation method. The mesoporous carbon support investigated as a potential alternative to Vulcan XC‐72 has a very high specific surface area and a narrow pore size distribution. The materials were characterized with XRD, TEM, SEM‐EDX, N2 sorption and steady state polarization. It was found that it is possible to increase the ORR reactivity using the microemulsion route for formation of Pt nanoparticles. It was concluded that the MEA processing conditions for the mesoporous carbon support have to be modified to reach improved ORR reactivity, likely due to the large differences in specific surface area, porosity and conductivity compared to the Vulcan carbon.
Protonic Electroceramics for Fuel Cells
Authors: Boehm E. , McEvoy A. J.
Published: November 2005

Whereas the conventional solid oxide fuel cell uses an oxygen‐ion conducting electroceramic, materials also exist which, at least over a restricted temperature range, perform as hydrogen ion, or proton, conductors. In principle, solid oxide fuel cells based on these materials are possible. With increasing temperature some degree of oxygen ion mobility is also observed, so that these materials are then mixed ionic conductors. The electrochemical characteristics observed may be influenced strongly by the choice and structure of the contacting electrode material. The open‐circuit voltage for example may be significantly less than that indicated by thermodynamics. In addition the external faradaic efficiency of ionic devices based on mixed conductivity electroceramics may also be reduced. The effects relate to the selectivity of the interface for charge exchange by the diverse carriers. Some results on perovskite cathodic materials contacting cerate protonic conductors are presented.
Electrochemical Impedance and X‐Ray Absorption Spectroscopy (EXAFS) as In‐Situ Methods to Study the PEMFC Anode
Authors: Mazurek M. , Benker N. , Roth C. , Buhrmester T. , Fuess H.
Published: November 2005

The effect of alloy formation on the performance of carbonsupported Pt and Ru fuel cell catalysts has been investigated by electrochemical impedance spectroscopy (EIS), X‐ray absorption spectroscopy (EXAFS) and fuel cell tests. The CO tolerance of the respective anode electrocatalysts has been tested in both reformate and methanol operation. This paper describes results for mixtures of carbon‐supported Pt and carbon‐supported Ru catalysts. The particle sizes of the active metals have been modified by heat‐treatment in nitrogen. It has been observed that the size of Pt and Ru particles has a significant influence on the electrochemical performance, the activity improving for smaller Ru particles. The performance of certain Pt‐Ru mixtures in a single cell fuel cell is comparable with an alloy catalyst.
Arterial spin labeling in small animals: Methods and applications to experimental cerebral ischemia
Authors: Thomas David L.
Published: November 2005

ASL enables noninvasive, quantitative monitoring of cerebral perfusion to be performed repeatedly over a period of hours. Thus, ASL is an attractive method for basic science studies of the time evolution and pathophysiology of diseases using animal models. In particular, ASL is valuable for basic science studies of evolving tissue status and viability in stroke using animal models of acute ischemia. This study describes both pulsed (PASL) and continuous ASL (CASL) studies of quantitative cerebral perfusion in rodent models of cerebral ischemia. Some technical factors pertinent to these studies are discussed, including a method for measuring arterial blood T1 and double‐echo PASL for measuring cerebral blood flow (CBF) and volume (CBV). Investigations of the CBF response to forebrain ischemia and reperfusion, and of regional variations in CBF and arterial transit time (ATT) are also discussed. J. Magn. Reson. Imaging 2005. © 2005 Wiley‐Liss, Inc.
Genetic, clinical, and imaging characterization of one patient with late‐onset, slowly progressive, pantothenate kinase‐associated neurodegeneration
Authors: Antonini Angelo , Goldwurm Stefano , Benti Riccardo , Prokisch Holger , Ebhardt Monika , Cilia Roberto , Zini Michela , Righini Andrea , Cossu Giovanni , Pezzoli Gianni
Published: November 2005

We report on a patient with late‐onset, pantothenate kinase‐associated neurodegeneration (PKAN) who revealed two new heterozygous mutations at gene testing and showed asymmetric moderately reduced striatal dopamine transporter binding with single photon emission computed tomography, possibly due to prolonged neuroleptic treatment. These findings expand the genetic and imaging spectrum of this rare disorder. © 2005 Movement Disorder Society
Clinical and genetic study of a Brazilian family with spastic paraplegia (SPG6 locus)
Authors: Munhoz Renato P. , Kawarai Toshitaka , Teive Helio A. , Raskin Salmo , Sato Christine , Liang Yan , St. George‐Hyslop Peter H. , Rogaeva Ekaterina
Published: November 2005

We describe a Brazilian family in which inheritance of a G106R mutation in the SPG6 gene (also know as NIPA1) resulted in an autosomal dominant form of hereditary spastic paraplegia (ADHSP). Clinical investigations indicated that this family has a pure form of spastic paraplegia. All patients presented with gait difficulty in their twenties, progressing to frank spastic paraplegia during the next decade. Our report further supports evidence that mutations in SPG6 cause ADHSP. © 2005 Movement Disorder Society
A method for modal reanalysis of topological modifications of structures
Authors: Yang Zhi Jun , Chen Su Huan , Wu Xiao Ming
Published: November 2005

A method for structural modal reanalysis for three cases of topological modifications, the number of degrees of freedom (DOFs) is unchanged, decreased, and increased, is presented. In this method, the newly added DOFs are linked to the original DOFs of the modified structure by means of the dynamic reduction so as to obtain the condensed equation. The methods for forming the stiffness and mass increments, ΔK and ΔM, resulting from the three cases of topological modifications of structures are discussed. The extended Kirsch method is used to improve the accuracy of the starting solutions of the initial structure. And then, the eigenvectors of newly added DOFs resulting from topological modification can be recovered. At last, the Rayleigh–Ritz analysis is used to evaluate the eigenvalues and eigenvectors for the modified structure. Three numerical examples are given to illustrate the applications of the present approach. The results show that the proposed method is effective for structural modal reanalysis of three cases of the topological modifications and it is easy to implement on a computer. By comparing with previous method, it can be seen that the present method can give good approximate eigenvalues and eigenvectors, even if the topological modifications are very large. Copyright © 2005 John Wiley & Sons, Ltd.
Isothermal crystallization and spherulite nucleation in blends of polypropylene with metallocene‐prepared polyethylene
Authors: Razavi‐Nouri Mohammad , Hay James N
Published: November 2005

The isothermal crystallization behavior and morphology of a polypropylene (PP)‐based copolymer, a metallocene‐prepared linear low‐density polyethylene (M‐LLDPE) and their three 10/90, 30/70 and 50/50 M‐LLDPE/PP blends have been investigated. The PP and M‐LLDPE contained 5 ethylene and 3.3 mol% hexene‐1 as a comonomer, respectively. Isothermal crystallization studies revealed a different temperature‐dependence on crystallization for M‐LLDPE, PP and their blends and the crystallization half‐life for the M‐LLDPE was higher than either PP or the blends at a certain temperature. The PP‐rich blends also showed a quite similar crystallization rate to that of PP. Investigations on the variation of spherulite growth rate of PP in the blends at different temperatures revealed no significant change and was quite independent of the amount of M‐LLDPE being employed. The morphology studies revealed that the nucleation densities of the PP spherulites decreased by introducing M‐LLDPE into PP and the M‐LLDPE remained as discrete droplets dispersed throughout the PP spherulites. The results obtained were consistent with no miscibility between the two components. Copyright © 2005 Society of Chemical Industry
Characterization of a laser‐nitrided titanium alloy by electron backscattered diffraction and electron probe microanalysis
Authors: Gordin D. M. , Gloriant T. , Bohn M. , Guillou A. , Thibon I. , Ansel D.
Published: November 2005

After a laser gas nitriding treatment of the Ti‐7.5Al (atom %) titanium‐based alloy, we used a combination of electron backscattered diffraction (EBSD) in scanning electron microscope and electron probe microanalysis (EPMA) techniques in order to efficiently characterize the different phases in the resolidified layer. Representative measurements of chemical composition and reliable determination of crystal structure were possible for each phase of the complex microstructure. The reaction zone is formed by a mixture of isostructural TiN phases with dendritic and/or ‘coarse’ needles morphology, fixed into a α′‐Ti matrix (martensite) with a thin needle aspect. The nitrogen solubility was found to remain very low in the α′‐Ti matrix (up to 2–3 atom %), while in the TiN phase, an aluminum solubility as high as 4 atom % was measured, reducing drastically the nitrogen content into a Ti79N17Al4 chemical composition. Copyright © 2005 John Wiley & Sons, Ltd.
The relationships of adolescent school‐related deviant behaviour and victimization with psychological distress: Testing a general model of the mediational role of parents and teachers across groups of gender and age
Authors: Herrero Juan , Estévez Estefanía , Musitu Gonzalo
Published: November 2005

Deviant behaviour and victimization at school have been consistently related to poor psychological adjustment in adolescents. This research explores the mediating role that parents and teachers have in adolescent psychological distress in 973 Spanish students aged 11–16 years old. Structural equation analyses results showed that adolescent deviant behaviour and victimization were positively related to psychological distress as seen by the total effects. However, while victimization was directly related to psychological distress, the association of deviant behaviour and psychological distress was mediated by adolescent–parent communication and adolescent–teacher relationships. Multigroup analyses showed that relationships among variables were not significantly different for groups of age and gender.
Development of monoclonal antibodies specific to urochordate intracellular epitopes
Authors: Lapidot Z. , Rinkevich B.
Published: November 2005

Sixteen monoclonal antibodies (MAbs) specific to 2 urochordate genera (Botryllus schlosseri and Botrylloides) intracellular epitopes were generated in mice immunized with a mixture of fresh and paraformaldehyde‐fixed cells obtained from animal's blood and cells from dissociated organs. Hybridoma clones were selected by ELISA tests and immunohistochemistry assays on paraffin‐embedded animal tissues. Five MAbs were tested for reactions with different zooidal organs and cell compartments; 7 MAbs were tested, separately, on 5 different botryllid colonies (3 Botryllus and 2 Botrylloides). The results revealed high polymorphism. Whereas some of the MAbs recognized, specifically, only part of the botryllid genotypes tested, others recognized only part of the cellular compartments. These MAbs will be used as an important tool in the study of botryllid ascidian immunology and developmental biology, revealing the first wide panel of MAbs specific to urochordate intracellular antigens.
Correlation of temperature induced conformation change with optimum catalytic activity in the recombinant G/11 xylanase A fromBacillus subtilisstrain 168 (1A1)
Authors: Murakami Mário T. , Arni Raghuvir K. , Vieira Davi S. , Degrève Léo , Ruller Roberto , Ward Richard J.
Published: November 2005

The 1.7 Å resolution crystal structure of recombinant family G/11 β‐1,4‐xylanase (rXynA) fromBacillus subtilis1A1 shows a jellyroll fold in which two curved β‐sheets form the active‐site and substrate‐binding cleft. The onset of thermal denaturation of rXynA occurs at 328 K, in excellent agreement with the optimum catalytic temperature. Molecular dynamics simulations at temperatures of 298–328 K demonstrate that below the optimum temperature the thumb loop and palm domain adopt a closed conformation. However, at 328 K these two domains separate facilitating substrate access to the active‐site pocket, thereby accounting for the optimum catalytic temperature of the rXynA.
FADD deficiency sensitises Jurkat T cells to TNF‐α‐dependent necrosis during activation‐induced cell death
Authors: Lawrence C.P. , Chow S.C.
Published: November 2005

Activation‐induced cell death (AICD) in activated T lymphocytes is largely mediated by Fas/Fas ligand (FasL) interaction. The cytoplasmic adaptor molecule Fas‐associated death domain protein (FADD) plays an essential role in the apoptotic signalling of the Fas death pathway. In the present study, we observed that FADD deficient (FADD−/−) Jurkat T cells undergo AICD to a similar extent as wild‐type cells. AICD in wild‐type Jurkat T cells is via apoptosis, whereas it is non‐apoptotic in FADD−/− cells. The latter took up propidium iodide, exhibit a loss in mitochondrial membrane potential and have no detectable cleavage products of caspase‐8 or ‐3 activation, suggesting that these cells die by necrosis. Wild‐type Jurkat T cells undergo apoptosis when incubated with recombinant FasL and Trail but not with TNF‐α. In contrast, FADD−/− Jurkat T cells are resistant to FasL and Trail but die of necrosis when incubated with TNF‐α. We showed that neutralising anti‐TNF‐α blocked AICD as well as TNF‐α‐induced necrosis in FADD−/− Jurkat T cells. Furthermore, downregulating the receptor interacting protein, RIP, with geldanamycin treatment, which is essential for TNF‐α signalling, markedly inhibited AICD in FADD−/− Jurkat T cells. In addition, caspase‐8‐deficient Jurkat T cells are resistant to Fas‐ and TNF‐α‐induced cell death. Taken together, our results suggest that a deficiency in FADD and not caspase‐8 or the inhibition of the Fas signalling pathway sensitises Jurkat T cells to TNF‐α‐dependent necrosis during AICD.
CHIP interacts with heat shock factor 1 during heat stress
Authors: Kim Soo-A , Yoon Jung-Hoon , Kim Do-Kyung , Kim Su-Gwan , Ahn Sang-Gun
Published: November 2005

Heat shock factor 1 (HSF1) is a major transactivator of heat shock genes in response to stress and mediates cell protection against various harmful conditions. In this study, we identified the interaction of CHIP (carboxyl terminus of the heat shock cognate protein 70‐interacting protein) with the N‐terminus of HSF1. Using GST full‐down assay, we found that CHIP directly interacts with C‐terminal deleted HSF1 (a.a. 1–290) but not with full‐length HSF1 under non‐stressed conditions. Interestingly, interaction of CHIP with full‐length HSF1 was induced by heat shock treatment. The structural change of HSF1 was observed under heat stressed conditions by CD spectra. These observations demonstrate the direct interaction between HSF1 and CHIP and this interaction requires conformational change of HSF1 by heat stress.
Recuperation and behaviour of Pacific cod after barotrauma
Authors: Nichol D.G. , Chilton E.A.
Published: November 2005

A total of 624 Pacific cod was captured, tagged with data-storage tags, and released in the Gulf of Alaska and eastern Bering Sea from 2001 to 2003. Cod were captured with pot or jig gear at depths ranging from 32 to 127 m. As of January 2004, 272 tags (44%) were recovered, with fish at liberty from 2 days to 1.5 years. The tags, which collected time, depth, and temperature information, revealed behaviour patterns common to nearly all recaptured fish. Analysis of swimbladder function suggests that these patterns resulted from swimbladder ruptures and deflation. In most cases, fish immediately dived to the bottom and then, within hours, returned to shallower depths. Fish that subsequently descended back to the depth at which they were captured, did so at rates ranging from 4.9 to 23.2 m day−1. Observations of bubbles being released from cod as they neared the surface during capture, indicated that cod swimbladders can rupture. A series of X-rays taken of live cod immediately after capture and subsequently at 24 h, revealed that ruptured swimbladders were sealed within 24 h. The loss of gas from the swimbladder, and the subsequent loss in buoyancy, inhibited most cod from remaining near the bottom. Their quick return to shallow water after an initial escape response indicates either a need or preference to reside at a depth at which they are more neutrally buoyant. Although rates of descent were highly variable among individuals, smaller individuals tended to descend faster than larger ones. Rates of descent were most likely limited by the secretion rate of gas into the swimbladder. Future tagging work for species such as Pacific cod need to recognize the recuperation period that is necessary before natural vertical or horizontal migrations can be evaluated.
Cervicography as an adjunctive test to visual inspection with acetic acid in cervical cancer detection screening
Authors: Bomfim‐Hyppólito S. , Santana Franco E. , Gomes de Matos Meneses Franco R. , Matos de Albuquerque C. , Nunes G.C.
Published: November 2005

Objective: Validate Digital Cervicography as adjunctive cervical cancer screening test to VIA and Cytology. Method: Women (1292) were submitted to both cytological and VIA tests to obtain a sample of 301 positive VIA cases (23.3%) which have had the Digital Cervicography (DC) taken and evaluated. Just cases considered positive by DC (149/301 cases — 49.5%) and/or positive Pap smear tests were referred to colposcopy and biopsy whenever indicated. Results: Cervical smear was positive in 5.4%, including LGSIL (4%), HGSIL (1%) and one case of invasive cancer (0.4%), and 1.6% of ASCUS or AGUS). DC identified 81 positive cases (74 LGSIL; 5 HGSIL; 2 cancers). The sensitivity of cytology was 14.8%, and the DC was 100%. Corresponding specificities were 95.4% and 69.1%, respectively. The NPV and PPV for DC were 100% and 54.4%. Conclusion: DC increases sensitivity, specificity and positive predictive value of VIA, becoming a valid adjunctive screening test for cervical cancer in low resource settings.
A taxonomy of manufacturing strategies in China
Authors: Zhao Xiande , Sum Chee‐Chuong , Qi Yinan , Zhang Huiying , Lee Tien‐Sheng
Published: November 2005

A taxonomy not only provides a parsimonious description of strategic groups that is useful in discussion and research, but also aids theory building. However, taxonomic studies in the operations strategy literature are scarce. Major studies that use North American or European data to develop taxonomies of manufacturing strategies contend that the applicability of their identified taxonomies to other countries remains unclear. Furthermore, the construction of theory is not complete without regular verification and replication to account for competitive paradigm shifts and new environmental imperatives. In our study, we replicated the well‐acknowledged taxonomy of manufacturing strategies of [Miller, J.G., Roth, A.V., 1994. A taxonomy of manufacturing strategies, Management Science 40 (3), 285–304] using data from one of the world's fastest growing economies—China. A taxonomy of manufacturing strategies is identified and is found to be different from the strategic clusters of Caretakers, Marketeers and Innovators in Miller and Roth. The underlying dimensions that defined our clusters are also different from those in Miller and Roth. Our study also derived an interesting insight that a taxonomy that is based on realized strength rather than emphasis on competitive capabilities can better explain a company's financial performance.
Geoarchaeological evidence for dredging in Tyre's ancient harbour, Levant
Authors: Marriner Nick , Morhange Christophe
Published: November 2005

Chrono-stratigraphic data from Tyre's ancient northern harbour delineate extensive dredging practices during the Greco-Roman and Byzantine periods. Radiocarbon dates from four cores consistently cluster between ca. 500 B.C. and 1000 A.D. and indicate rapid rates of sedimentation in the basin, namely ∼10 mm/yr during the Greco-Roman and Byzantine periods, compared to 0.5–1 mm/yr for the period 6000–4000 B.C. Absence of strata between 4000 B.C. and 500 B.C. is not consistent with a natural base-level sediment sink and cannot be interpreted as a depositional hiatus in the high-stand systems tract. Ancient dredging is further corroborated by persistent age-depth inversions within the fine-grained harbour facies. These data support removal of Middle Bronze Age to Persian period sediment strata, with deliberate overdeepening of the harbour bottom by Greco-Roman and Byzantine societies.
Lack of BRCA2 alterations in primary head and neck squamous cell carcinoma
Authors: Nawroz‐Danish H. Myra , Koch Wayne M. , Westra William H. , Yoo George , Sidransky David
Published: November 2005

We previously demonstrated that loss of 13q occurred in greater than 50% of primary head and neck squamous cell carcinomas. Although the minimal region of loss at 13q14.1–14.3 included the Rb1 gene, Rb1 inactivation was found to be rare. To further investigate possible targets of 13q loss in head and neck cancer, 32 primary tumors were fine mapped by microsatellite analysis with the use of 10 new markers spanning the minimal region. Twenty‐one (66%) of 32 tumors displayed loss of heterozygosity and once again the minimal region of loss was confirmed to be 13q14.1–14.3. In addition to 6 monosomies, 11 tumors had regions of loss that either selectively deleted (one tumor) or stretched into the BRCA2 region 13q12–13 (10 tumors). Therefore we pursued investigation of the BRCA2 gene by a coupled transcription and translation assay of its largest exon (exon 11; 4932 base pairs) to detect functional truncations indicative of mutation in 37 primary head and neck tumors with 13q loss. These tumors included 17 of the 32 tumors recently analyzed and 20 other tumors with 13q loss from a previous study. Additionally, we performed the transcription and translation assay on five head and neck cancer cell lines. We found no alterations in exon 11 of the BRCA2 gene in any of the tumors or cell lines suggesting that perhaps another tumor suppressor gene on 13q is involved in head and neck cancer. (Otolaryngol Head Neck Surg 1998; 119:21–5.)
Vestibular adaptation to space in monkeys
Authors: Dai Mingjia , Raphan Theodore , Kozlovskaya Inessa , Cohen Bernard
Published: November 2005

Otolith‐induced eye movements of rhesus monkeys were studied before and after the 1989 COSMOS 2044 and the 1992 to 1993 COSMOS 2229 flights. Two animals flew in each mission for approximately 2 weeks. After flight, spatial orientation of the angular vestibulo‐ocular reflex was altered. In one animal the time constant of postrotatory nystagmus, which had been shortened by head tilts with regard to gravity before flight, was unaffected by the same head tilts after flight. In another animal, eye velocity, which tended to align with a gravitational axis before flight, moved toward a body axis after flight. This shift of orientation disappeared by 7 days after landing. After flight, the magnitude of compensatory ocular counter‐rolling was reduced by about 70% in both dynamic and static tilts. Modulation in vergence in response to naso‐occipital linear acceleration during off‐vertical axis rotation was reduced by more than 50%. These changes persisted for 11 days after recovery. An up and down asymmetry of vertical nystagmus was diminished for 7 days. Gains of the semicircular canal‐induced horizontal and vertical angular vestibuloocular reflexes were unaffected in both flights, but the gain of the roll angular vestibuloocular reflex was decreased. These data indicate that there are short‐ and long‐term changes in otolith‐induced eye movements after adaptation to microgravity. These experiments also demonstrate the unique value of the monkey as a model for studying effects of vestibular adaptation in space. Eye movements can be measured in three dimensions in response to controlled vestibular and visual stimulation, and the results are directly applicable to human beings. Studies in monkeys to determine how otolith afferent input and central processing is altered by adaptation to microgravity should be an essential component of future space‐related research. (Otolaryngol Head Neck Surg 1998;119:65‐77.)
Balance disorders in older persons: Quantification with posturography
Authors: Baloh Robert W. , Jacobson Kathleen M. , Enrietto Jane A. , Corona Sonia , Honrubia Vicente
Published: November 2005

We measured sway velocity using static and dynamic posturography in a group of young normal subjects and two groups of subjects older than 75 years; one older group considered their balance normal for their age, and the other reported imbalance. The latter group consisted of patients with documented peripheral and central vestibular disorders and patients with dizziness and imbalance of unknown cause. The velocity of sway was higher in older subjects than in younger subjects and in older subjects who reported imbalance than in age‐matched controls. The difference was greater with dynamic posturography than with static posturography, but the posturography data provided little information about the cause of the imbalance and did not correlate with the frequency of reported falls. (Otolaryngol Head Neck Surg 1998;119:89‐92.)
Autonomic reaction to vestibular damage
Authors: Yates Bill J.
Published: November 2005

The vestibular system provides inputs to many neurons in the brain stem that participate in autonomic control. This multiplicity of vestibular‐autonomic connections plays a variety of roles. Whereas it has been known for decades that unilateral vestibular lesions can result in motion sickness, recent data suggest that the vestibular system participates in making adjustments in blood pressure and respiration that are necessary to maintain homeostasis during movement and changes in posture. Animals with bilateral vestibular lesions are more susceptible to posturally related hypotension than vestibularly intact animals, and it is also possible that orthostatic hypotension after space flight is caused in part by microgravity‐related changes in otolith function. Patients with vestibular lesions could also be more vulnerable to respiratory disturbances related to posture, such as obstructive apnea. Vestibular dysfunction has additionally been linked with anxiety disorders, such as agoraphobia, which may result from alteration of vestibular inputs to brain stem monoaminergic neurons (which are known to process these signals). Even sleep disturbances might be connected with vestibular disorders because neurons in the pontine reticular formation that are critical in switching between sleep states may be influenced by labyrinthine inputs. Thus it is likely that vestibular damage will result in a number of parallel disturbances in autonomic function. (Otolaryngol Head Neck Surg 1998;119:106‐12.)
Value of repeated fine‐needle aspiration cytology and cytologic experience on the management of thyroid nodules
Authors: Aguilar Jose , Rodriguez Jose M. , Flores Benito , Sola Joaquin , Bas Agueda , Soria Teresa , Ramirez Pablo , Parrilla Pascual
Published: November 2005

Although fine‐needle aspiration is being currently accepted as the most reliable method to select patients with thyroid nodules for surgery, controversy remains about the accuracy in distinguishing benign nodules. We present our results from 636 fine‐needle aspirations performed from 1984 to 1989. Our article focuses on the value of cytologic expertise and repeated punctures for follow‐up of benign nodules. We found annual figures for specificity and positive predictive value to increase steadily from 1984 to 1989, thus suggesting that the power of the test is proportional to the experience of the cytologist. We also state that the value of performing repeated punctures for the follow‐up of unselected benign nodules is low. (Otolaryngol Head Neck Surg 1998;119:121‐4.)
Isolated Cervical Tuberculosis in Patients with HIV Infection
Authors: SINGH BHUVANESH , Balwally Atul N. , Har‐El Gady , Lucente Frank E.
Published: November 2005

OBJECTIVE

Tuberculosis isolated to the head and neck region is common in patients with HIV infection. However, the management of isolated head and neck tuberculosis has not been reported in the literature. This study was done to describe the characteristics of tuberculosis isolated to the head and neck region in patients infected with HIV and to detect differences in presentation and diagnostic management based on the status of HIV infection at presentation.

METHODS

A retrospective study was performed including 38 patients infected with HIV who were seen with tuberculosis isolated to the head and neck region at two tertiary care centers during a 10‐year period. These patients were divided into two groups on the basis of the HIV status at presentation, which indirectly reflects the level of immunosuppression. Group 1 included 11 patients (29%) with AIDS at presentation. Group 2 included 27 patients (71%) with HIV infection but not AIDS.

RESULTS

The cervical lymphatics were the most common site for isolated head and neck tuberculosis (89%), with the supraclavicular nodes most often involved (53%). Extralymphatic involvement was less common (11%), but involved a variety of anatomic locations (skin, spinal cord, larynx, parotid). The presenting history and physical examination had a low sensitivity for tuberculosis in patients with HIV infection, mainly because of the presence of multiple confounding factors. Purified protein derivative testing was highly sensitive for tuberculosis in patients with HIV infection alone (61%); however, its usefulness was diminished in patients with AIDS (14%; p = 0.03). Fine‐needle aspiration biopsy was 94% sensitive for diagnosing tuberculosis and was not affected by the status of HIV infection. Surgical biopsy was the gold standard for diagnosing tuberculosis but was associated with chronically draining fistulas in a significant number of cases (14%).

CONCLUSIONS

These data suggest that tuberculosis should be considered in the differential diagnosis of all head and neck lesions in patients infected with HIV, even in the absence of pulmonary involvement. Purified protein derivative testing should be done liberally in these patients, with realization that the sensitivity of purified protein derivative testing is reduced in patients with AIDS. Fine‐needle aspiration biopsy should be the key diagnostic test in this patient population, with open surgical biopsy reserved for highly suspicious cases in which other measures were not diagnostic. (Otolaryngol Head Neck Surg 1998;118:766‐70.)
Initial Report on Postoperative Healing after Endoscopic Sinus Surgery With the Microdebrider
Authors: Bernstein Joseph M. , Lebowitz Richard A. , Jacobs Joseph B.
Published: November 2005

Synechiae formation is a frequent occurrence after endoscopic sinus surgery and may cause symptomatic sinus outflow tract obstruction. Various means are used to reduce the incidence of synechiae formation. These include meticulous operative technique, partial middle turbinate resection, middle meatus spacers or stents, and postoperative debridement. The microdebrider is a powered rotary shaving device that precisely resects tissue, minimizing inadvertent mucosal trauma and stripping. We present 40 cases of endoscopic sinus surgery performed with the microdebrider. Patients had at least a 5‐month follow‐up and demonstrated rapid mucosal healing, minimal crust formation, and a low incidence of synechiae formation. These initial data suggest that the microdebrider may be advantageous in surgery for chronic sinusitis. (Otolaryngol Head Neck Surg 1998;118:800–3.
Histopathology of Human Temporal Bone AfterCis‐Platinum, Radiation, or Both
Authors: Hoistad Dick L. , Ondrey Frank G. , Mutlu Cemil , Schachern Patricia A. , Paparella Michael M. , Adams George L.
Published: November 2005

Preserving organs by use of multiple modalities has become protocol in treating squamous cell carcinomas of the head and neck, butcis‐platinum and radiation can impair hearing. To determine the effect ofcis‐platinum, radiation, or a combination of these treatments on the temporal bone, we studied histopathologic slides of 15 human temporal bones: four aftercis‐platinum, five after radiation, two after combined treatment, and four from normal controls. Hair cells and cells in spiral ganglia were counted in reconstructed organs of Corti. Lumen‐to‐diameter indexes in arterioles near facial nerves were quantified for four normal controls and seven irradiated patients. Available audiograms were compared. Decreased spiral ganglion cells, loss of inner and outer hair cells, and atrophy of stria vascularis were demonstrated in groups receivingcis‐platinum, radiation, and combinations, compared with age‐matched controls. Arterioles around facial nerves demonstrated fibrinous clots within the intima, endothelial proliferation, and hypertrophy and fibrosis of vascular walls in smooth muscle. Fibrosis in connective tissue was clearly progressive after radiation.Cis‐platinum and radiation can contribute to otologic sequelae, including sensorineural hearing losses, vascular changes, serous effusion, or fibrosis. Prophylactic treatments and techniques to deliver them should be considered for protection of temporal bones and preservation of hearing after oncologic modalities. (Otolaryngol Head Neck Surg 1998;118:825–32.)