bluuebunny/crossref_metadata_2025 huggingface dataset:
Nuclear Magnetic Resonance
Authors: Jameson Cynthia J , Yamaguchi M , Fukui Hiroyuki , Kamienska-Trela Krystyna , Fawcett Allan H , Weingartner H , Harris Kenneth D M , Aliev A E , Fisher Julie , Arnold J R P , Williams Steve S C R , Barber Jill , Wood Brian , Ramanathan K V , Prior Malcolm J W , Lian Lu Yun , Khetrapal C L
Published: March 2007

As a spectroscopic method, Nuclear Magnetic Resonance (NMR) has seen spectacular growth over the past two decades, both as a technique and in its applications. Today the applications of NMR span a wide range of scientific disciplines, from physics to biology to medicine. Each volume of Nuclear Magnetic Resonance comprises a combination of annual and biennial reports which together provide comprehensive of the literature on this topic. This Specialist Periodical Report reflects the growing volume of published work involving NMR techniques and applications, in particular NMR of natural macromolecules which is covered in two reports: "NMR of Proteins and Acids" and "NMR of Carbohydrates, Lipids and Membranes". For those wanting to become rapidly acquainted with specific areas of NMR, this title provides unrivalled scope of coverage. Seasoned practitioners of NMR will find this an in valuable source of current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.
Nuclear Magnetic Resonance
Authors: Jameson Cynthia J , Fukui Hiroyuki , Kamienska-Trela Krystyna , Aliev A E , Prior Malcolm J W , Ryan T A , Wojcik Jacek , Sharp Robert , Khan Ali , Watanabe Tokuko , Schilf Wojciech , Ludwig Ralf , Kurosu Hiromichi , Yamanobe Takeshi , Barsukov I , Hounsell E F , De Dios Angel C , Law Robert V , Ando S , Kuroki Shigeki , Matthews S J , Baba Takehisa
Published: March 2007

As a spectroscopic method, Nuclear Magnetic Resonance (NMR) has seen spectacular growth over the past two decades, both as a technique and in its applications. Today the applications of NMR span a wide range of scientific disciplines, from physics to biology to medicine. Each volume of Nuclear Magnetic Resonance comprises a combination of annual and biennial reports which together provide comprehensive of the literature on this topic. This Specialist Periodical Report reflects the growing volume of published work involving NMR techniques and applications, in particular NMR of natural macromolecules which is covered in two reports: "NMR of Proteins and Acids" and "NMR of Carbohydrates, Lipids and Membranes". For those wanting to become rapidly acquainted with specific areas of NMR, this title provides unrivalled scope of coverage. Seasoned practitioners of NMR will find this an in valuable source of current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.
Nuclear Magnetic Resonance
Authors: Jameson Cynthia J , Fukui Hiroyuki , Kamienska-Trela Krystyna , Aliev A E , Khetrapal C L , Ramanathan K V , Prior Malcolm J W , Wojcik Jacek , Sharp Robert , Watanabe Tokuko , Schilf Wojciech , Ludwig Ralf , Kurosu Hiromichi , Yamanobe Takeshi , Barsukov I , Hounsell E F , De Dios Angel C , Law Robert V , Kuroki Shigeki , Gowda G A N , Matthews S J , Baba Toshihide , Monduzzi M , Asakawa N , Yasunaga H
Published: March 2007

As a spectroscopic method, nuclear magnetic resonance (NMR) has seen spectacular growth over the past two decades, both as a technique and in its applications. Today the applications of NMR span a wide range of scientific disciplines, from physics to biology to medicine. Each volume of Nuclear Magnetic Resonance comprises a combination of annual and biennial reports which together provide comprehensive coverage of the literature on this topic. This Specialist Periodical Report reflects the growing volume of published work involving NMR techniques and applications, in particular NMR of natural macromolecules which is covered in two reports: "NMR of Proteins and Nucleic Acids" and "NMR of Carbohydrates, Lipids and Membranes". For those wanting to become rapidly acquainted with specific areas of NMR, this title provides unrivalled scope of coverage. Seasoned practitioners of NMR will find this an invaluable source of current methods and applications. Volume 34 covers literature published from June 2003 to May 2004. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.
Organometallic Chemistry
Authors: Wardell J L , Housecroft Catherine E , Molloy K C , Armitage D A , Timney J A , Hogarth G , Evans D G , Butler I R , Turner M L , Simpson S J
Published: March 2007

Organometallic chemistry is an interdisciplinary science which continues to grow at a rapid pace. Although there is continued interest in synthetic and structural studies the last decade has seen a growing interest in the potential of organometallic chemistry to provide answers to problems in catalysis synthetic organic chemistry and also in the development of new materials. This Specialist Periodical Report aims to reflect these current interests reviewing progress in theoretical organometallic chemistry, main group chemistry, the lanthanides and all aspects of transition metal chemistry. Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.
Organophosphorus Chemistry
Authors: Allen Christopher W , Edmundson R S , Dahl O , Hall C Dennis
Published: March 2007

Organophosphorus Chemistry provides a comprehensive annual review of the literature. Coverage includes phosphines and their chalcogenides, phosphonium salts, low coordination number phosphorus compounds, penta- and hexa-coordinated compounds, tervalent phosphorus acids, nucleotides and nucleic acids, ylides and related compounds, and phosphazenes. The series will be of value to research workers in universities, government and industrial research organisations, whose work involves the use of organophosphorus compounds. It provides a concise but comprehensive survey of a vast field of study with a wide variety of applications, enabling the reader to rapidly keep abreast of the latest developments in their specialist areas. Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.
Photochemistry
Authors: Cundall R B , Horspool William M , Allen Norman S , Cox Alan , Reid S T
Published: March 2007

The breadth of scientific and technological interests in the general topic of photochemistry is truly enormous and includes, for example, such diverse areas as microelectronics, atmospheric chemistry, organic synthesis, non-conventional photoimaging, photosynthesis, solar energy conversion, polymer technologies, and spectroscopy. This Specialist Periodical Report on Photochemistry aims to provide an annual review of photo-induced processes that have relevance to the above wide-ranging academic and commercial disciplines, and interests in chemistry, physics, biology and technology. In order to provide easy access to this vast and varied literature, each volume of Photochemistry comprises sections concerned with photophysical processes in condensed phases, organic aspects which are sub-divided by chromophore type, polymer photochemistry, and photochemical aspects of solar energy conversion. Volume 34 covers literature published from July 2001 to June 2002. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.
Spectroscopic Properties of Inorganic and Organometallic Compounds
Authors: Mann Brian E , Dillon Keith B , Clark Stephen J , Donaldson John D , Rankin David W H , Robertson Heather E , Mehta Lina
Published: March 2007

Spectroscopic Properties of Inorganic and Organometallic Compounds provides a unique source of information on an important area of chemistry. Divided into sections mainly according to the particular spectroscopic technique used, coverage in each volume includes: NMR (with reference to stereochemistry, dynamic systems, paramagnetic complexes, solid state NMR and Groups 13-18); nuclear quadrupole resonance spectroscopy; vibrational spectroscopy of main group and transition element compounds and coordinated ligands; and electron diffraction. Reflecting the growing volume of published work in this field, researchers will find this Specialist Periodical Report an invaluable source of information on current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading experts in their specialist fields, this series is designed to help the chemistry community keep current with the latest developments in their field. Each volume in the series is published either annually or biennially and is a superb reference point for researchers. www.rsc.org/spr
Spectroscopic Properties of Inorganic and Organometallic Compounds
Authors: Dillon Keith B , Rankin David W H
Published: March 2007

This series provides an unequalled source of information on an area of chemistry that continues to grow in importance. Divided into sections mainly according to the particular spectroscopic technique used, coverage in each volume includes: NMR (with reference to stereochemistry, dynamic systems, paramagnetic complexes, solid state NMR and Groups 13-18); nuclear quadrupole resonance spectroscopy; vibrational spectroscopy of main group and transition element compounds and coordinated ligands; and electron diffraction. Reflecting the growing volume of published work in the field, researchers will find this an invaluable source of information on current methods and applications. Volume 39 provides a critical review of the literature published up to late 2004.
Chemical Modelling
Authors: Simos Theodore E , Wilson Stephen , Springborg Michael , Pugh David , Lewis Richard A , Trinajstic Nedad , Travis Karl , Sutcliffe Brian T , Mulholland Adrian , Karadakov Peter B , Bernhardt Debra J , Sholl David , Todd Billy D
Published: March 2007

Chemical Modelling: Applications and Theory comprises critical literature reviews of molecular modelling, both theoretical and applied. Molecular modelling in this context refers to modelling the structure, properties and reactions of atoms, molecules & materials. Each chapter is compiled by experts in their fields and provides a selective review of recent literature. With chemical modelling covering such a wide range of subjects, this Specialist Periodical Report serves as the first port of call to any chemist, biochemist, materials scientist or molecular physicist needing to acquaint themselves of major developments in the area. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis. Current subject areas covered are Amino Acids, Peptides and Proteins, Carbohydrate Chemistry, Catalysis, Chemical Modelling. Applications and Theory, Electron Paramagnetic Resonance, Nuclear Magnetic Resonance, Organometallic Chemistry. Organophosphorus Chemistry, Photochemistry and Spectroscopic Properties of Inorganic and Organometallic Compounds. From time to time, the series has altered according to the fluctuating degrees of activity in the various fields, but these volumes remain a superb reference point for researchers.
Photodynamic Therapy with ALA
Authors: Barr Hugh , Betz C S , Curnow A , Fehr M , Hillemanns P , Hornung R , Kennedy J C , Leunig A , Malik Z , Messmann H , Schleyer V , Stummer W , Szeimies R M , Waidelich R ,   The European Society of Photobiology
Published: March 2007

Photodynamic therapy (PDT) is increasingly being used amongst health practitioners in combating a variety of diseases. One common strategy used during this light activated process is to induce the accumulation of significant amounts of a photosensitising agent in the diseased tissue. The naturally occurring amino acid 5-aminovulinic acid (ALA) is used to produce high levels of the photosensitizer, Protoprophyin IX, in the therapy known as ALA-PDT. Written by experts in the field Photodynamic therapy with ALA outlines a variety of clinical approaches to the topic, outlining current applications. These include the use of ALA-PDT and ALA-FD (fluorescence diagnosis) in the areas of dermatology, urology, brain, otorhinolaryngology, gynaecology and gastroenterology. Also included is a chapter that comprehensively reviews the scientific principles of ALA-PDT. Primarily aimed at a clinical audience Photodynamic therapy with ALA should provide a comprehensive review and useful insight into ALA-PDT.
Organophosphorus Chemistry
Authors: Allen Christopher W , Edmundson R S , Dahl O , Hall C Dennis , Grasby Jane A , Williams David M , Tebby John C , Slinn Robert
Published: March 2007

Organophosphorus Chemistry provides a comprehensive annual review of the literature. Coverage includes phosphines and their chalcogenides, phosphonium salts, low coordination number phosphorus compounds, penta- and hexa-coordinated compounds, tervalent phosphorus acids, nucleotides and nucleic acids, ylides and related compounds, and phosphazenes. The series will be of value to research workers in universities, government and industrial research organisations, whose work involves the use of organophosphorus compounds. It provides a concise but comprehensive survey of a vast field of study with a wide variety of applications, enabling the reader to rapidly keep abreast of the latest developments in their specialist areas. Specialist Periodical Reports provide systematic and detailed review coverage of progress in the major areas of chemical research. Written by experts in their specialist fields the series creates a unique service for the active research chemist, supplying regular critical in-depth accounts of progress in particular areas of chemistry. For over 80 years the Royal Society of Chemistry and its predecessor, the Chemical Society, have been publishing reports charting developments in chemistry, which originally took the form of Annual Reports. However, by 1967 the whole spectrum of chemistry could no longer be contained within one volume and the series Specialist Periodical Reports was born. The Annual Reports themselves still existed but were divided into two, and subsequently three, volumes covering Inorganic, Organic and Physical Chemistry. For more general coverage of the highlights in chemistry they remain a 'must'. Since that time the SPR series has altered according to the fluctuating degree of activity in various fields of chemistry. Some titles have remained unchanged, while others have altered their emphasis along with their titles; some have been combined under a new name whereas others have had to be discontinued. The current list of Specialist Periodical Reports can be seen on the inside flap of this volume.
Amino Acids, Peptides and Proteins
Authors: Elmore Don T , Higton Avril , Chan Weng , Penke Botond , Toth Gabor , Varadi Gyorgyi
Published: March 2007

In an ever-increasing domain of activity, Amino Acids, Peptides and Proteins provides an annual compilation of the world's research effort into this important area of biological chemistry. Volume 34 provides a review of literature published during 2001. Comprising a comprehensive review of significant developments at this biology/chemistry interface, each volume opens with an overview of amino acids and their applications. Work on peptides is reviewed over several chapters, ranging from current trends in their synthesis and conformational and structural analysis, to peptidomimetics and the discovery of peptide-related molecules in nature. The application of advanced techniques in structural elucidation is incorporated into all chapters, whilst periodic chapters on metal complexes of amino acids, peptides and beta-lactams extend the scope of coverage. Efficient searching of specialist topics is facilitated by the sub-division of chapters into discrete subject areas, allowing annual trends to be monitored. All researchers in the pharmaceutical and allied industries, and at the biology/chemistry interface in academia will find this an indispensable reference source. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading authorities in the relevant subject areas, the series creates a unique service for the active research chemist, with regular, in-depth accounts of progress in particular fields of chemistry. Subject coverage within different volumes of a given title is similar and publication is on an annual or biennial basis.
Boronic Acids in Saccharide Recognition
Authors: James Tony D , Phillips Marcus D , Shinkai Seiji
Published: March 2007

The desire to quantify the presence of analytes within diverse physiological, environmental and industrial systems has led to the development of many novel detection methods. In this arena, saccharide analysis has exploited the pair-wise interaction between boronic acids and saccharides. Boronic Acids in Saccharide Recognition provides a comprehensive review and critical analysis of the current developments in this field. It also assesses the potential of this innovative approach, outlining future lines of research and possible applications. Topics include: the molecular recognition of saccharides, the complexation of boronic acids with saccharides, fluorescent sensors and the modular construct of fluorescent sensors, further sensory systems for saccharide recognition and an extensive bibliography. This high level book is ideal for researchers both academic and industrial who require a comprehensive overview of the subject.
Insulin-mimetic and insulin-sensitizing activities of a pentacyclic triterpenoid insulin receptor activator
Authors: Jung Seung H. , Ha Yun J. , Shim Eun K. , Choi Soo Y. , Jin Jing L. , Yun-Choi Hye S. , Lee Jong R.
Published: March 2007

Five pentacyclic triterpenoids isolated from Campsis grandiflora were tested for insulin-mimetic and insulin-sensitizing activity. The compounds enhanced the activity of insulin on tyrosine phosphorylation of the IR (insulin receptor) β-subunit in CHO/IR (Chinese-hamster ovary cells expressing human IR). Among the compounds tested, CG7 (ursolic acid) showed the greatest enhancement and CG11 (myrianthic acid) the least. We characterized the effect of CG7 further, and showed that it acted as an effective insulin-mimetic agent at doses above 50 μg/ml and as an insulin-sensitizer at doses as low as 1 μg/ml. Additional experiments showed that CG7 increased the number of IRs that were activated by insulin. This indicates that a major mechanism by which CG7 enhances total IR auto-phosphorylation is by promoting the tyrosine phosphorylation of additional IRs. CG7 not only potentiated insulin-mediated signalling (tyrosine phosphorylation of the IR β-subunit, phosphorylation of Akt and glycogen synthase kinase-3β), but also enhanced the effect of insulin on translocation of glucose transporter 4 in a classical insulin-sensitive cell line, 3T3-L1 adipocytes. The results of the present study demonstrate that a specific pentacyclic triterpenoid, CG7, exerts an insulin-sensitizing effect as an IR activator in CHO/IR cells and adipocytes. The enhancement of insulin activity by CG7 may be useful for developing a new class of specific IR activators for treatment of Type 1 and Type 2 diabetes.
SUMF1 enhances sulfatase activitiesin vivoin five sulfatase deficiencies
Authors: Fraldi Alessandro , Biffi Alessandra , Lombardi Alessia , Visigalli Ilaria , Pepe Stefano , Settembre Carmine , Nusco Edoardo , Auricchio Alberto , Naldini Luigi , Ballabio Andrea , Cosma Maria Pia
Published: March 2007

Sulfatases are enzymes that hydrolyse a diverse range of sulfate esters. Deficiency of lysosomal sulfatases leads to human diseases characterized by the accumulation of either GAGs (glycosaminoglycans) or sulfolipids. The catalytic activity of sulfatases resides in a unique formylglycine residue in their active site generated by the post-translational modification of a highly conserved cysteine residue. This modification is performed by SUMF1 (sulfatase-modifying factor 1), which is an essential factor for sulfatase activities. Mutations in the SUMF1 gene cause MSD (multiple sulfatase deficiency), an autosomal recessive disease in which the activities of all sulfatases are profoundly reduced. In previous studies, we have shown that SUMF1 has an enhancing effect on sulfatase activity when co-expressed with sulfatase genes in COS-7 cells. In the present study, we demonstrate that SUMF1 displays an enhancing effect on sulfatases activity when co-delivered with a sulfatase cDNA via AAV (adeno-associated virus) and LV (lentivirus) vectors in cells from individuals affected by five different diseases owing to sulfatase deficiencies or from murine models of the same diseases [i.e. MLD (metachromatic leukodystrophy), CDPX (X-linked dominant chondrodysplasia punctata) and MPS (mucopolysaccharidosis) II, IIIA and VI]. The SUMF1-enhancing effect on sulfatase activity resulted in an improved clearance of the intracellular GAG or sulfolipid accumulation. Moreover, we demonstrate that the SUMF1-enhancing effect is also present in vivo after AAV-mediated delivery of the sulfamidase gene to the muscle of MPSIIIA mice, resulting in a more efficient rescue of the phenotype. These results indicate that co-delivery of SUMF1 may enhance the efficacy of gene therapy in several sulfatase deficiencies.
Substrate specificity and effect on GLUT4 translocation of the Rab GTPase-activating protein Tbc1d1
Authors: Roach William G. , Chavez Jose A. , Mîinea Cristinel P. , Lienhard Gustav E.
Published: March 2007

Insulin stimulation of the trafficking of the glucose transporter GLUT4 to the plasma membrane is controlled in part by the phosphorylation of the Rab GAP (GTPase-activating protein) AS160 (also known as Tbc1d4). Considerable evidence indicates that the phosphorylation of this protein by Akt (protein kinase B) leads to suppression of its GAP activity and results in the elevation of the GTP form of a critical Rab. The present study examines a similar Rab GAP, Tbc1d1, about which very little is known. We found that the Rab specificity of the Tbc1d1 GAP domain is identical with that of AS160. Ectopic expression of Tbc1d1 in 3T3-L1 adipocytes blocked insulin-stimulated GLUT4 translocation to the plasma membrane, whereas a point mutant with an inactive GAP domain had no effect. Insulin treatment led to the phosphorylation of Tbc1d1 on an Akt site that is conserved between Tbc1d1 and AS160. These results show that Tbc1d1 regulates GLUT4 translocation through its GAP activity, and is a likely Akt substrate. An allele of Tbc1d1 in which Arg125 is replaced by tryptophan has very recently been implicated in susceptibility to obesity by genetic analysis. We found that this form of Tbc1d1 also inhibited GLUT4 translocation and that this effect also required a functional GAP domain.
Thrifty Tbc1d1 and Tbc1d4 proteins link signalling and membrane trafficking pathways
Authors: Koumanov Françoise , Holman Geoffrey D.
Published: March 2007

Establishing a complete pathway which links occupancy of the insulin receptor to GLUT4 translocation has been particularly elusive because of the complexities involved in studying both signalling and membrane trafficking processes. However, Lienhard's group has now discovered two related molecules that could function in this linking role. These proteins, Tbc1d4 (also known as AS160) and now Tbc1d1, as reported in this issue of the Biochemical Journal, have been demonstrated to be Rab GAPs (GTPase-activating proteins) that link upstream to Akt (protein kinase B) and phosphoinositide 3-kinase and downstream to Rabs involved in trafficking of GLUT4 vesicles. The data from Leinhard and colleagues suggest that high levels of Rab GAP activity lead to suppression of GLUT4 translocation and this observation has wide significance and is likely to be relevant to the recent discovery that mutations in the Tbc1d1 gene lead to some cases of severe human obesity.
Nonmagnetic impurities in a two-leg Hubbard ladder
Authors: Medhi Amal , Basu Saurabh , Kadolkar Charudatt
Published: March 2007

Magnetic correlations are studied in a two-leg Hubbard ladder doped with nonmagnetic impurities using finite temperature quantum Monte Carlo (FTQMC) method. A number of relevant macroscopic quantities calculated as a function of temperature T and impurity concentration are found to exhibit significantly renormalized behavior, a feature noted in many experiments. The uniform magnetic susceptibility χ0(T) for the impurity doped system shows a cusplike behavior followed by a sharp increase at lower temperatures, signaling the formation of impurity induced free magnetic moments, while it diminishes rapidly for the pure system. The spin correlations are found to increase in the vicinity of an impurity. To investigate the effect of nonmagnetic impurities on the spin wave modes in the system, spin wave velocity vsw is calculated as a function of impurity concentration. The result shows that vsw is reduced by nonmagnetic impurities, indicating softening of the modes. Simulations are performed slightly away from half filling and kinetic energy of the electrons in the neighborhood of an impurity site is calculated to study the interplay between impurities and holes. However, contrary to previous experimental observations on two dimensional lattices where nonmagnetic impurities reduce hole mobility, no noticeable effect of impurity on the mobility of the neighboring electrons is found in our calculation.
Consolidation of Nd–Fe–B melt-spun ribbon by compression shearing method
Authors: Saito Tetsuji , Takeishi Hiroyuku , Nakayama Noboru
Published: March 2007

Commercially available Nd–Fe–B melt-spun ribbons (MQ powders) were consolidated at temperatures ranging from room temperature to 573K in ambient atmosphere by the compression shearing method. The resultant bulk materials consisted of the Nd2Fe14B phase together with a small amount of the soft magnetic α-iron phase. The bulk material consolidated at room temperature was magnetically isotropic as was the case for the MQ powders. On the other hand, the bulk material consolidated at 573K was found to be magnetically anisotropic and showed a remanence of 9.2kG, higher than that of the MQ powders.
Effect of B to Si concentration ratio on glass-forming ability and soft-magnetic properties in (Co0.705Fe0.045B0.25−xSix)96Nb4 glassy alloys
Authors: Shen Baolong , Zhou Yijun , Chang Chuntao , Inoue Akihisa
Published: March 2007

The effect of B to Si concentration ratio on the glass-forming ability (GFA) and soft-magnetic properties of (Co0.705Fe0.045B0.25−xSix)96Nb4 (x=0.02–0.1) alloys was investigated. The (Co0.705Fe0.045B0.25−xSix)96Nb4 bulk glassy alloys with diameters up to 2mm were synthesized in the composition range of x=0.02–0.06. In addition to high GFA, the Co-based glassy alloys exhibit excellent soft-magnetic properties as well, i.e., rather high saturation magnetization of 0.62T, low coercive force of 0.6–1A∕m, and superhigh initial permeabilities of 37 100–53 700 at 1kHz under a field of 1A∕m. The alloys with Si contents of x=0.05 and 0.06 exhibit high initial permeabilities of 29 300 and 24 300, respectively, even at 100kHz.
Simulation of nonlinear shear rheology of dilute salt-free polyelectrolyte solutions
Authors: Stoltz Christopher , de Pablo Juan J. , Graham Michael D.
Published: March 2007

Brownian dynamics simulations are used to conduct a systematic analysis of the nonlinear shear rheology of dilute polyelectrolyte solutions, exploring its relationship to shear rate, Bjerrum length, and concentration. A simple coarse-grained bead-spring chain model that incorporates explicit counterions is used. It is found that the polyelectrolyte chains exhibit a shear thinning behavior at high shear rate (as characterized by bead Peclet number Pe) that is independent of the electrostatic strength due to the stripping of ions from close proximity to the chain caused by the flow. In contrast, at low values of Pe, the viscosity increases monotonically with increasing Bjerrum length over the range studied here, in contrast to the nonmonotonic trend displayed by the chain size. Furthermore, at fixed Bjerrum length, the reduced viscosity increases monotonically with concentration. The mechanism underlying these observations is essentially the primary electroviscous effect; the ion cloud surrounding a polyelectrolyte chain deforms in flow, causing a significant increase in viscosity as concentration increases. Finally, the authors have also considered the role of hydrodynamic interactions in these simulations, finding that for low concentration studies in shear flow, these do not qualitatively affect the results.
The electrostatic surface term: (I) Periodic systems
Authors: Herce Henry David , Garcia Angel Enrique , Darden Thomas
Published: March 2007

The authors propose a new approach to understand the electrostatic surface contributions to the interactions of large but finite periodic distributions of charges. They present a simple method to derive and interpret the surface contribution to any electrostatic field produced by a periodic distribution of charges. They discuss the physical and mathematical interpretations of this term. They present several examples and physical details associated with the calculation of the surface term. Finally, they provide a simple derivation of the surface contribution to the virial. This term does not disappear even if tinfoil boundary conditions are applied.
Memory characteristics of Co nanocrystal memory device with HfO2 as blocking oxide
Authors: Yang F. M. , Chang T. C. , Liu P. T. , Yeh P. H. , Yu Y. C. , Lin J. Y. , Sze S. M. , Lou J. C.
Published: March 2007

In this letter, the Co nanocrystals using SiO2 and HfO2 as the tunneling and the control dielectric with memory effect has been fabricated. A significant memory effect was observed through the electrical measurements. Under the low voltage operation of 5V, the memory window was estimated to ∼1V. The retention characteristics were tested to be robust. Also, the endurance of the memory device was not degraded up to 106 write/erase cycles. The processing of the structure is compatible with the current manufacturing technology of semiconductor industry.
Investigation of dielectric barrier discharge dependence on permittivity of barrier materials
Authors: Li Ruixing , Tang Qing , Yin Shu , Sato Tsugio
Published: March 2007

It has been evidenced by both theory and experiments that a barrier possessing a high permittivity can create a high energy for dielectric barrier discharge. However, this argument was challenged by the recent experiments of the authors. They found an optimum permittivity value to generate denser and stronger microdischarges, as well as a high reactivity of destruction CO2 in the entire gap space for plasma chemistry. When the barrier permittivity was higher than this optimum value, the microdischarges became sparser and even extinguished since the large number of charges resulted from higher permittivity accumulated on the dielectric surface to reduce the electric field.
Thickness dependence of in-plane dielectric and ferroelectric properties of Ba0.7Sr0.3TiO3 thin films epitaxially grown on LaAlO3
Authors: Zhou X. Y. , Wang D. Y. , Zheng R. K. , Tian H. Y. , Qi J. Q. , Chan H. L. W. , Choy C. L. , Wang Y.
Published: March 2007

The authors have studied the effects of film thickness on the lattice strain and in-plane dielectric and ferroelectric properties of Ba0.7Sr0.3TiO3 thin films epitaxially grown on LaAlO3 (001) single crystal substrates. With increasing film thickness from 20to300nm, the in-plane lattice parameter (a) increased from 0.395to0.402nm while the out-of-plane lattice parameter (c) remained almost unchanged, which led to an increased a∕c ratio (tetragonality) changing from 0.998 to 1.012 and consequently resulted in a shift of Curie temperature from 306to360K associated with an increase of the in-plane remnant polarization and dielectric constant of the film.
Persistent photoconductivity in p-type ZnO(N) grown by molecular beam epitaxy
Authors: Polyakov A. Y. , Smirnov N. B. , Govorkov A. V. , Belogorokhov A. I. , Kozhukhova E. A. , Markov A. V. , Osinsky A. , Dong J. W. , Pearton S. J.
Published: March 2007

Current transport mechanisms and persistent photoconductivity effects were studied in nitrogen-doped ZnO films grown by molecular beam epitaxy having p-type or n-type conductivity at 25°C. In both types of samples the current flow is determined by the n-type channels surrounded by higher resistivity regions. The persistent photoconductivity wave form is reasonably described by the stretched-exponents-type expression, with only a slight temperature dependence of the characteristic decay time. The persistent photocurrent decay process is greatly accelerated by infrared illumination (threshold energy of the photons ∼1.4eV). The results suggest that the Fermi level in the higher resistivity regions is pinned near Ev+1.9±0.1eV and the height of the potential barrier for electrons in the n-type channels is around 1.4±0.1eV.
From Excess Commuting to Commuting Possibilities: More Extension to the Concept of Excess Commuting
Authors: Charron Mathieu
Published: March 2007

The excess-commuting literature provides a methodological framework in which the observed average commute ( Cobs) is compared with theoretical commuting values: the minimum ( Cmin) and maximum ( Cmax) average commute. In this paper, I argue that real spatial behavior is ill represented by the two assumptions of optimal (minimizing or maximizing) behavior. Cmin and Cmax are in fact extreme values of a much richer distribution of commuting possibilities. I argue that all those possibilities should be taken into account in the evaluation of Cobs. In order to do this, I develop a probabilistic framework where any urban form is associated with a statistical distribution of commuting possibilities, with an average and a standard deviation, within which Cmin and Cmax represent extreme and very improbable outcomes. Applied to a sample of fifty metropolitan areas, this framework helps us understand the combined association of spatial behavior and urban form with commuting.
Depth, sediment type, biogeography and high species richness in shallow-water benthos
Authors: Coleman Noël , Cuff Wilfred , Moverley John , Gason Anne S. H. , Heislers Simon
Published: March 2007

Until recently, quantitative data on the benthic fauna along the coast of Victoria, south-east Australia, were restricted to those few areas (potentially) receiving commercial and industrial effluent. Collectively, studies in these areas covered ~50 to 60 km of a coastline that extends for 1000 km. Recently, samples were taken from depths of 10, 20 and 40 m along the entire coast, and analysis of these made it possible to examine benthic community structure throughout the region. Species richness is high along the entire length of the coast, supporting the argument that species richness in temperate areas is not always higher in the deep sea than in shallow water. The major factor influencing species richness was depth. Although slightly more individuals were collected from stations at 10-m depth than from stations at 40-m depth, almost three times as many species were found at the deeper stations. Sediment type also influenced species richness. For the stations at 40-m depth, species richness was ~25% higher in medium and coarse sands than in fine sand. Pattern analysis suggested some bioregionalisation of the fauna, but the effect of geographical location on affinities among sample stations was much less than the effects of depth and sediment type.
Ecosystem metabolism in a dryland river waterhole
Authors: Fellows C. S. , Wos M. L. , Pollard P. C. , Bunn S. E.
Published: March 2007

Little is known about ecosystem processes in dryland rivers, despite the global distribution of these systems. Those in Australia are characterised by long periods of no flow in which they persist for many months as series of isolated, often turbid, waterholes. We assessed benthic and pelagic primary production, respiration, and bacterial production in one of these waterholes to determine the metabolic balance of the waterhole and resolve the relative importance of autochthonous and allochthonous sources of organic carbon. Despite a photic zone depth of only 0.25 m, three lines of evidence suggested that autochthonous sources of organic carbon were important for fuelling bacterial production under no-flow conditions: the metabolic balance of the waterhole was not indicative of large allochthonous inputs; rates of gross primary production were great enough to meet a substantial fraction of estimated bacterial carbon demand; and pathways for allochthonous carbon to enter the waterhole were limited. These results suggest that models of lake metabolism based on temperate ecosystems can be expanded to include dryland river waterholes, which group with eutrophic lakes owing to their high levels of inorganic nutrients, low allochthonous inputs and autotrophic metabolic balance.
Plectin 1f scaffolding at the sarcolemma of dystrophic (mdx) muscle fibers through multiple interactions with β-dystroglycan
Authors: Rezniczek Günther A. , Konieczny Patryk , Nikolic Branislav , Reipert Siegfried , Schneller Doris , Abrahamsberg Christina , Davies Kay E. , Winder Steve J. , Wiche Gerhard
Published: March 2007

In skeletal muscle, the cytolinker plectin is prominently expressed at Z-disks and the sarcolemma. Alternative splicing of plectin transcripts gives rise to more than eight protein isoforms differing only in small N-terminal sequences (5–180 residues), four of which (plectins 1, 1b, 1d, and 1f) are found at substantial levels in muscle tissue. Using plectin isoform–specific antibodies and isoform expression constructs, we show the differential regulation of plectin isoforms during myotube differentiation and their localization to different compartments of muscle fibers, identifying plectins 1 and 1f as sarcolemma-associated isoforms, whereas plectin 1d localizes exclusively to Z-disks. Coimmunoprecipitation and in vitro binding assays using recombinant protein fragments revealed the direct binding of plectin to dystrophin (utrophin) and β-dystroglycan, the key components of the dystrophin–glycoprotein complex. We propose a model in which plectin acts as a universal mediator of desmin intermediate filament anchorage at the sarcolemma and Z-disks. It also explains the plectin phenotype observed in dystrophic skeletal muscle of mdx mice and Duchenne muscular dystrophy patients.
Bub1 is essential for assembly of the functional inner centromere
Authors: Boyarchuk Yekaterina , Salic Adrian , Dasso Mary , Arnaoutov Alexei
Published: March 2007

During mitosis, the inner centromeric region (ICR) recruits protein complexes that regulate sister chromatid cohesion, monitor tension, and modulate microtubule attachment. Biochemical pathways that govern formation of the inner centromere remain elusive. The kinetochore protein Bub1 was shown to promote assembly of the outer kinetochore components, such as BubR1 and CENP-F, on centromeres. Bub1 was also implicated in targeting of Shugoshin (Sgo) to the ICR. We show that Bub1 works as a master organizer of the ICR. Depletion of Bub1 from Xenopus laevis egg extract or from HeLa cells resulted in both destabilization and displacement of chromosomal passenger complex (CPC) from the ICR. Moreover, soluble Bub1 controls the binding of Sgo to chromatin, whereas the CPC restricts loading of Sgo specifically onto centromeres. We further provide evidence that Bub1 kinase activity is pivotal for recruitment of all of these components. Together, our findings demonstrate that Bub1 acts at multiple points to assure the correct kinetochore formation.
Alteration of Epithelial Structure and Function Associated with PtdIns(4,5)P2 Degradation by a Bacterial Phosphatase
Authors: Mason David , Mallo Gustavo V. , Terebiznik Mauricio R. , Payrastre Bernard , Finlay B. Brett , Brumell John H. , Rameh Lucia , Grinstein Sergio
Published: March 2007

Elucidation of the role of PtdIns(4,5)P2 in epithelial function has been hampered by the inability to selectively manipulate the cellular content of this phosphoinositide. Here we report that SigD, a phosphatase derived from Salmonella, can effectively hydrolyze PtdIns(4,5)P2, generating PtdIns(5)P. When expressed by microinjecting cDNA into epithelial cells forming confluent monolayers, wild-type SigD induced striking morphological and functional changes that were not mimicked by a phosphatase-deficient SigD mutant (C462S). Depletion of PtdIns(4,5)P2 in intact SigD-injected cells was verified by detachment from the membrane of the pleckstrin homology domain of phospholipase Cδ, used as a probe for the phosphoinositide by conjugation to green fluorescent protein. Single-cell measurements of cytosolic pH indicated that the Na+/H+ exchange activity of epithelia was markedly inhibited by depletion of PtdIns(4,5)P2. Similarly, anion permeability, measured using two different halide-sensitive probes, was depressed in cells expressing SigD. Depletion of PtdIns(4,5)P2 was associated with marked alterations in the actin cytoskeleton and its association with the plasma membrane. The junctional complexes surrounding the injected cells gradually opened and the PtdIns(4,5)P2-depleted cells eventually detached from the monolayer, which underwent rapid restitution. Similar observations were made in intestinal and renal epithelial cultures. In addition to its effects on phosphoinositides, SigD has been shown to convert inositol 1,3,4,5,6-pentakisphosphate (IP5) into inositol 1,4,5,6-tetrakisphosphate (IP4), and the latter has been postulated to mediate the diarrhea caused by Salmonella. However, the effects of SigD on epithelial cells were not mimicked by microinjection of IP4. In contrast, the cytoskeletal and ion transport effects were replicated by hydrolyzing PtdIns(4,5)P2 with a membrane-targeted 5-phosphatase or by occluding the inositide using high-avidity tandem PH domain constructs. We therefore suggest that opening of the tight junctions and inhibition of Na+/H+ exchange caused by PtdIns(4,5)P2 hydrolysis combine to account, at least in part, for the fluid loss observed during Salmonella-induced diarrhea.
Uncoupling and Turnover in a Cl−/H+ Exchange Transporter
Authors: Walden Michael , Accardi Alessio , Wu Fang , Xu Chen , Williams Carole , Miller Christopher
Published: March 2007

The CLC-family protein CLC-ec1, a bacterial homologue of known structure, stoichiometrically exchanges two Cl− for one H+ via an unknown membrane transport mechanism. This study examines mutations at a conserved tyrosine residue, Y445, that directly coordinates a Cl− ion located near the center of the membrane. Mutations at this position lead to “uncoupling,” such that the H+/Cl− transport ratio decreases roughly with the volume of the substituted side chain. The uncoupled proteins are still able to pump protons uphill when driven by a Cl− gradient, but the extent and rate of this H+ pumping is weaker in the more uncoupled variants. Uncoupling is accompanied by conductive Cl− transport that is not linked to counter-movement of H+, i.e., a “leak.” The unitary Cl− transport rate, measured in reconstituted liposomes by both a conventional initial-velocity method and a novel Poisson dilution approach, is ∼4,000 s−1 for wild-type protein, and the uncoupled mutants transport Cl− at similar rates.