bluuebunny/crossref_metadata_2025 huggingface dataset:
Application of the Mean-Field Approximation to the Magnetic and Superconducting Phases of Quasi-One-Dimensional Metal
Authors: Rozhkov A.V.
Published: September 2009

We research under what condition the mean-field approximation can be applied to study ordered phases of quasi-one-dimensional metal. It is shown that the mean-field treatment is indeed permissible provided that it is applied not to the microscopic Hamiltonian (subject to severe one-dimensional high-energy fluctuations), but rather to effective Hamiltonian derived at the dimensional crossover scale. The resultant mean-field phase diagram has three ordered phases: spin density wave, charge density wave, and superconductivity. The density wave orders win if the Fermi surface nests well. Outcome of competition between the intra-chain and inter-chain electron repulsion determines the type (spin vs. charge) of the density wave. The ground state becomes superconducting (with unconventional order parameter) when the nesting is poor. The superconducting mechanism relies crucially on the one-dimensional fluctuations.
Tensile Stress-Strain Relationships of Magnetorheological Fluids under Various Factors
Authors: Mazlan Saiful Amri , Issa Ahmed , Chowdhury H.A. , Olabi Abdul Ghani
Published: September 2009

This paper presents experimental investigations of three MR fluid types under the influence of several factors in tension loading mode. One MR fluid was water-based, MRF-241ES, while the other two were both hydro-carbon based, MRF-132DG and MRF-122-2ED. The magnetic properties of the MR fluids varied significantly due to a higher particle density in the water-based MR fluid compared to the hydrocarbon-based MR fluids. Tension as a squeeze mode, is as an operational mode where two flat parallel surfaces, standing opposite to each other, are pulled apart from each other by an external force, acting along the path of the magnetic flux lines. The experiments were performed in a vertical direction in the environment of a DC magnetic field. Stress-strain curves of the MR fluids under tension showed similar characteristics despite the fact that different types of the carrier fluids were used. The results revealed that the magnitude of the stress, for a given strain value, depended on the applied current and the initial gap size. It was found that, for higher applied currents and smaller initial gap sizes, there were larger stress values. However, the tensile speed had no significant effect on the stress-strain curves of MR fluids.
Monte Carlo Study of Magnetostructural Phase Transitions in Ni50Mn25+xSb25-x Heusler Alloys
Authors: Sokolovskiy V.V. , Buchelnikov Vasiliy D. , Taskaev Sergey
Published: September 2009

On the basis of Monte Carlo simulations, we investigate the temperature dependence of magnetization of Ni-Mn-Sb Heusler alloys, in which the part of the Mn atoms interact antiferromagnetically. It is shown that this antiferromagnetic exchange is responsible for existence of several magnetic phase transitions in the Heusler alloys. For a certain set of parameters of the model Hamiltonian we obtain coupled martensitic and magnetic phase transitions. Results of simulations agree in an excellent way with the experimental magnetization curves.
Sensor of Current or Magnetic Field Based on Magnetoresistance Effect in (La0.7Ca0.3)0.8Mn1.2O3 Manganite Film
Authors: Dyakonov V.P. , Piechota S. , Piotrowski K. , Szewczyk A. , Szymczak H. , Mikhaylov V. , Shemiakov A. , Pashchenko A. , Pashchenko V.P.
Published: September 2009

The main objective of the performed investigations was to enhance sensitivity of a current sensor to weak changes of magnetic field. New design of the sensor of current based on magnetoresistance effect – MRE (MRE = (RH - R0)/R0 , where RH is the resistance in magnetic field and R0 is the resistance without magnetic field) was developed. The sensor was produced in the form of an annular magnet with a gap, in which the (La0.7Sr0.3)0.8Мn1.2О3 manganite film possessing large negative MRE was inserted. Nominal current in a controllable electric circuit can change from a few tenths parts of ampere to a hundred of amperes. The limit detectable change of current value depends on the size of gap in the annular magnet. The operation time of sensor at current overload and short circuit is less than 0.3 sec. These magnetoresistors are thermally stable over the temperature range from (- 50 ° С) to (+ 50 ° С). Proposed sensors based on MRE can be applied in many electrical arrangements and devices.
Differential Magnetoelastic Compressive Force Sensor Utilizing Two Amorphous Alloy Ring Cores
Authors: Bieńkowski Adam , Szewczyk Roman , Salach Jacek , Kolano Roman
Published: September 2009

Paper presents the results of investigation on functional characteristics of magnetoelastic compressive force sensor utilizing two Fe81Si4B15 amorphous alloy ring-shaped cores. Uniform distribution of stresses in one of two cores was achieved owing to special non-magnetic backings. Signal from sensing coils of cores was connected to differential amplifier, whereas sine wave voltage signal was applied to magnetizing circuit. High stress sensitivity of developed sensor was indicated together with expected reduction of temperature sensitivity of magnetoelastic sensor. These results confirm, that differential configuration of magnetoelastic sensor is suitable for practical application in sensors development.
SMA Thin Strip for Rotary-Driving Element
Authors: Tobushi Hisaaki , Pieczyska Elzbieta , Nowacki W.K. , Sugimoto Y.
Published: September 2009

If a shape-memory alloy (SMA) thin strip is applied as an element subjected to torsion, a rotary driving element with a simple mechanism can be developed. The torsion tests were carried out for the SMA thin strip. Torque and recovery torque, both increase in proportion to the angle of twist and temperature. The recoverable strain energy increases in proportion to temperature. The dissipated work decreases slightly with an increase in temperature. A means of opening and closing a door with an element driven by an SMA thin strip is demonstrated.
Structure and Properties of the High Temperature Nitrided/Oxided Surface of Ni-Ti Alloy
Authors: Lelątko Józef , Goryczka Tomasz , Wierzchoń Tadeusz , Morawiec Henryk
Published: September 2009

The nearly-equiatomic NiTi (50.6 at.%Ni, Af = 10°C) alloy was nitrided at 1073 K using glow discharge technique. Additionally, at the end of the nitriding some amount of oxygen was added.
Phase identification and thickness of the nitrided/oxided layer was done using electron microscopy method and the X-ray reflectivity measurements. The chemical composition of the layers was determined using energy dispersive spectrometer.
Combination of nitriding and oxidation of the NiTi surface produces nitride/oxide complex layer of a nanocrystalline structure. The average thickness of the obtained layer was about 0,5 μm.
The potentiodynamical studies in Tyrod’s solution reveal good corrosion resistance of obtained nitrided/oxidized NiTi surface proving its high quality.
FePt Nanorods and Nanowires for Novel Ferrofluids
Authors: Wu Zhen Yu , Dong Hai Long , Chuvilin Andrey L. , Wiedwald Ulf , Han Lu Yang , Krill III Carl E.
Published: September 2009

The preparation of a novel ferrofluid out of one-dimensional magnetic structures is attempted by the reverse-micelle-based wet-chemical formation of FePt nanowires and nanorods. The latter were found to manifest lengths ranging from 25 to 250 nm, with an average diameter of only 1.5 to 2 nm. X-ray diffraction and high-resolution TEM revealed a polycrystalline microstructure, with individual grains having the disordered fcc structure in the as-prepared state; a thermally induced transition to the chemically ordered phase was observed around 550°C. The samples were determined to be superparamagnetic at room temperature, with the blocking temperature measured to be ~26 K.
Microscopic Analysis of Track Etched Polymeric Membranes
Authors: Acharya N.K.
Published: September 2009

The bombardment of energetic ions on polymer membranes will produce the loosely bound passage in the membrane structure due to the energy loss. The Swift Heavy Ions (SHI) creates the latent tracks of several nm surrounded by several tens of nm track halo. The tracks can be visualized under Atomic Force Microscope after wet chemical etching. In present study the polymeric membranes of 30 μm was prepared by solution cast method and irradiated by 60 MeV C+5 energetic ions. The electronic energy losses are predominant at high energies. The membranes were etched chemically to convert the tracks in to suitable pores. The Atomic Force Microscopy (AFM) gives the size and distribution of the pores. The pore size is observed in nano regime. The pore density was found to depend on the irradiation dose.
Monodispersed Magnetic Fluids: Synthesis and Characterization
Authors: Parekh Kinnari , Upadhyay R.V. , Aswal V.K.
Published: September 2009

Magnetite and Co ferrite particles were synthesized with control of particle size distribution via non-aqueous route. The XRD pattern shows the formation of single phase spinel structure with the particle size of 96 Å and 80 Å respectively for magnetite and cobalt ferrite. TEM image of the same shows the particles are nearly spherical with the size matches with that obtained from X-ray and the size distribution is less than 5%. Magnetic measurement also shows the particles of uniform size with high value of saturation magnetization at room temperature compared to that obtained by other route. SANS study confirms our results of monodispersed particles with spherical shape.
Synthesis and Characterization of Magnetoelectric Nanocomposites
Authors: Yadav Kanhaiya Lal
Published: September 2009

A simple citrate gel process was used to prepare nanocomposites of xCuFe2O4–(1−x)BiFeO3 (henceforth, CFBF) and xNi0.75Co0.25Fe2O4-(1-x)BiFeO3 (henceforth, NCFBF) with x=0.1, 0.2, 0.3 and 0.4. The phase was found to be formed at 500 °C and 700 °C for CFBF and NCFBF respectively. TEM observation showed that the average particles size is around 40 nm. The variation of the dielectric constant and the dielectric loss with frequency showed dispersion in the low frequency range. All the samples exhibit strong magnetic characteristics. The coercivity and squareness increased with the increase in annealing temperature and were maximum for samples annealed at 500°C and 700°C for CFBF and NCFBF nanocomposites, respectively, and further decrease in coercivity is attributed to decrease in aspect ratio and pinning effects in the nanocrysatllites. The ME coefficient αE showed strong dependence on HBias and maximum value of ME coefficients were 303 and 309 mV/cm Oe at magnetic field frequency of 50 kHz for CFBF and NCFBF nanocomposites respectively. The large values of ME coefficients are attributed to low coercivity, large magnetization and small crystallite size of constituent phases.
Quantum Transport in Bridge Systems
Authors: Maiti Santanu K.
Published: September 2009

We study electron transport properties of some molecular wires and a unconventional disordered thin film within the tight-binding framework using Green's function technique. We show that electron transport is significantly affected by quantum interference of electronic wave functions, molecule-to-electrode coupling strengths, length of the molecular wire and disorder strength. Our model calculations provide a physical insight to the behavior of electron conduction across a bridge system.
Persistent Current in Metallic Rings and Cylinders
Authors: Maiti Santanu K.
Published: September 2009

We explore the behavior of persistent current and low-field magnetic response in mesoscopic one-channel rings and multi-channel cylinders within the tight-binding framework. We show that the characteristic properties of persistent current strongly depend on total number of electrons , chemical potential μ, randomness and total number of channels. The study of low-field magnetic response reveals that only for one-channel rings with fixed , sign of the low-field currents can be predicted exactly, even in the presence of disorder. On the other hand, for multi-channel cylinders, sign of the low-field currents cannot be mentioned exactly, even in the perfect systems with fixed as it significantly depends on the choices of , μ, number of channels, disordered configurations, etc.
Percutaneous Management of a Long Saphenous Vein Graft Aneurysm: A Case Report and Review of Literature
Authors: Panetta Carmelo J. , Schneider Williaim , Boller Max A.
Published: September 2009

Aneurysms of saphenous vein grafts are rare but can result in complications such as myocardial infarction or death. Percutaneous treatment has included a variety of approaches, including covered stents. Long aneurysms in saphenous vein grafts pose an additional challenge due to the lack of coronary covered stents with sufficient length. We present successful treatment of a long saphenous vein graft aneurysm with use of peripheral covered stents over two coronary guidewires, a 55-centimeter 8-French sheath and no guide catheter.
Idiopathic Hypertrophic Pyloric Stenosis in an Adult, a Potential Mimic of Gastric Carcinoma
Authors: Zarineh Alireza , Leon Marino E. , Saad Reda S. , Silverman Jan F.
Published: September 2009

Primary or idiopathic hypertrophy of the pyloric muscle (IHPM) is a rare entity with uncertain pathogenesis which both clinically and pathologically mimics gastric cancer. We present a rare late-occurring case of IHPM in a 71-year-old Caucasian man with no apparent predisposing factor. Imaging studies demonstrated gastric distension with air fluid levels and no evidence of extrinsic compression. At upper endoscopy, massive gastric distension and no evidence of any ulcer or other mucosal defects were observed. Microscopically, marked hypertrophy of muscularis mucosa with smooth muscle cells arranged in whorls and fascicles was present which gradually transitioned to normal areas. The muscle fibers stained with smooth muscle actin and trichrome stain highlighted fibrosis between the muscle fibers. Although uncommon, IHPM can clinically and histologically mimic other proliferations in the gastric wall, such as gastrointestinal stromal tumor or a spindle cell neoplasm. The recent advances in understanding the pathogenesis of IHPM are discussed.
The Importance of Biological Databases in Biological Discovery
Authors: Baxevanis Andreas D.
Published: September 2009

Biological databases play a central role in bioinformatics. They offer scientists the opportunity to access a wide variety of biologically relevant data, including the genomic sequences of an increasingly broad range of organisms. This unit provides a brief overview of major sequence databases and portals, such as GenBank, the UCSC Genome Browser, and Ensembl. Model organism databases, including WormBase, the Arabidopsis Information Resource (TAIR), and those made available through the Mouse Genome Informatics (MGI) resource are also covered. Non‐sequence‐centric databases such as Online Mendelian Inheritance in Man (OMIM), the Protein Data Bank (PDB), MetaCyc, and the Kyoto Encyclopedia of Genes and Genomes (KEGG) are also discussed. Curr. Protoc. Bioinform. 27:1.1.1‐1.1.6. © 2009 by John Wiley & Sons, Inc.
Searching Online Mendelian Inheritance in Man (OMIM) for Information on Genetic Loci Involved in Human Disease
Authors: Borate Bhavesh , Baxevanis Andreas D.
Published: September 2009

Online Mendelian Inheritance in Man (OMIM) is a comprehensive compendium of information on human genes and genetic disorders, with a particular emphasis on the interplay between observed phenotypes and underlying genotypes. This unit focuses on the basic methodology for formulating OMIM searches and illustrates the types of information that can be retrieved from OMIM, including descriptions of clinical manifestations resulting from genetic abnormalities. This unit also provides information on additional relevant medical and molecular biology databases. A basic knowledge of OMIM should be part of the armamentarium of physicians and scientists with an interest in research on and clinical aspects of genetic disorders. Curr. Protoc. Bioinform. 27:1.2.1‐1.2.13. © 2009 by John Wiley & Sons, Inc.
An Introduction to Sequence Similarity (“Homology”) Searching
Authors: Stormo Gary D.
Published: September 2009

Homologous sequences usually have the same, or very similar, functions, so new sequences can be reliably assigned functions if homologous sequences with known functions can be identified. Homology is inferred based on sequence similarity, and many methods have been developed to identify sequences that have statistically significant similarity. This unit provides an overview of some of the basic issues in identifying similarity among sequences and points out other units in this chapter that describe specific programs that are useful for this task. Curr. Protoc. Bioinform. 27:3.1.1‐3.1.7. © 2009 by John Wiley & Sons, Inc.
Using OrthoCluster for the Detection of Synteny Blocks Among Multiple Genomes
Authors: Vergara Ismael A. , Chen Nansheng
Published: September 2009

Synteny blocks are composed of two or more orthologous genes conserved among species, resulting from speciation from their last common ancestor. OrthoCluster (Zeng et al., 2008) is a fast and easy‐to‐use program for the identification of synteny blocks among multiple genomes. It allows users to identify synteny blocks that contain different types of mismatches, and to decide whether they require conservation of gene orientation and conservation of gene order within the blocks. OrthoCluster can also be used to find duplicated blocks within genomes. Although genes and their correspondence are usually used as input for OrthoCluster, in fact, OrthoCluster can be applied using any type of markers as input as long as their relationships can be established. OrthoClusterDB provides a Web interface for running OrthoCluster with user‐defined datasets and parameters, as well as for browsing and downloading precomputed synteny blocks for different groups of genomes. Curr. Protoc. Bioinform. 27:6.10.1‐6.10.18. © 2009 by John Wiley & Sons, Inc.
Extracting Biological Meaning from Large Gene Lists with DAVID
Authors: Huang Da Wei , Sherman Brad T. , Zheng Xin , Yang Jun , Imamichi Tomozumi , Stephens Robert , Lempicki Richard A.
Published: September 2009

High‐throughput genomics screening studies, such as microarray, proteomics, etc., often result in large, “interesting” gene lists, ranging in size from hundreds to thousands of genes. Given the challenges of functionally interpreting such large gene lists, it is necessary to incorporate bioinformatics tools in the analysis. DAVID is a Web‐based application that provides a high‐throughput and integrative gene functional annotation environment to systematically extract biological themes behind large gene lists. High‐throughput gene functional analysis with DAVID will provide important insights that allow investigators to understand the biological themes within their given genomic study. This unit will describe step‐by‐step procedures to use DAVID tools, as well as a brief rationale and key parameters in the DAVID analysis. Curr. Protoc. Bioinform. 27:13.11.1‐13.11.13. © 2009 by John Wiley & Sons, Inc.
Asbestos fiber concentration in the area surrounding a former asbestos cement plant and excess mesothelioma deaths in residents
Authors: Kumagai Shinji , Kurumatani Norio
Published: September 2009

Background

Many persons who had lived near a former asbestos cement plant (AC plant) died from mesothelioma in Amagasaki city, Japan.

Methods

Asbestos fiber concentration in the area surrounding the AC plant was estimated so that the female mesothelioma death number predicted by a mathematical model was the same as the observed excess death number. We used the estimated asbestos fiber concentration to predict the excess mesothelioma deaths from 1970 to 2049.

Results

In a grid just south of the AC plant, the fiber concentration was estimated to be more than 3 f/ml for KM (asbestos potency factor for mesothelioma) of 7.75 × 10−9. An uncertainty factor of five yields a KM range 1.55 × 10−9 to 38.8 × 10−9; these in turn correspond to fiber concentrations of 15 and 0.6 f/ml. For KM = 7.75 × 10−9, grid units with higher fiber concentrations than 0.01 f/ml were estimated to extend 4.1 km (95% CI: 3.8–4.4 km) south‐southwest of the plant. Over the 80‐year study period (1970 to 2049), we predicted that the exposure under study will cause 346 excess mesothelioma deaths with range of 296 to 382 deaths.

Conclusions

This prediction suggests that considerable medical resources will be needed through 2049 as a result of past asbestos exposure in this region. Am. J. Ind. Med. 52:790–798, 2009. © 2009 Wiley‐Liss, Inc.
Computational investigation of the conformational profile of the four stereomers of Ac‐L‐Pro‐c3Phe‐NHMe (c3Phe= 2,3‐methanophenylalanine)
Authors: Rodriguez Alejandro , Canto Josep , Corcho Francesc J. , Perez Juan J.
Published: September 2009

The present report regards a computational study aimed at assessing the conformational profile of the four stereoisomers of the peptide Ace‐Pro‐c3Phe‐NMe, previously reported to exhibit β‐turn structures in dichloromethane with different type I/type II β‐turn profiles. Molecular systems were represented at the molecular mechanics level using the parm96 parameterization of the AMBER force field. Calculations were carried out in dichloromethane using an implicit solvent approach. Characterization of the conformational features of the peptide analogs was carried out using simulated annealing (SA), molecular dynamics (MD) and replica exchange molecular dynamics (REMD). Present results show that MD calculations do not provide a reasonable sampling after 300 ns. In contrast, both SA and REMD provide similar results and agree well with experimental observations. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 518–524, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Conformational properties of angiotensin II and its active and inactive TOAC‐labeled analogs in the presence of micelles. Electron paramagnetic resonance, fluorescence, and circular dichroism studies
Authors: Vieira Renata F. F. , Casallanovo Fábio , Marín Nélida , Paiva Antonio C. M. , Schreier Shirley , Nakaie Clóvis R.
Published: September 2009

The interaction between angiotensin II (AII, DRVYIHPF) and its analogs carrying 2,2,6,6‐tetramethylpiperidine‐1‐oxyl‐4‐amino‐4‐carboxylic acid (TOAC) and detergents —negatively charged sodium dodecyl sulfate (SDS) and zwitterionicN‐hexadecyl‐N,N‐dimethyl‐3‐ammonio‐1‐propanesulfonate (HPS)—was examined by means of EPR, CD, and fluorescence. EPR spectra of partially active TOAC1‐AII and inactive TOAC3‐AII in aqueous solution indicated fast tumbling, the freedom of motion being greater at the N‐terminus. Line broadening occurred upon interaction with micelles. Below SDS critical micelle concentration, broader lines indicated complex formation with tighter molecular packing than in micelles. Small changes in hyperfine splittings evinced TOAC location at the micelle‐water interface. The interaction with anionic micelles was more effective than with zwitterionic micelles. Peptide‐micelle interaction caused fluorescence increase. The TOAC‐promoted intramolecular fluorescence quenching was more pronounced for TOAC3‐AII because of the proximity between the nitroxide and Tyr4. CD spectra showed that although both AII and TOAC1‐AII presented flexible conformations in water, TOAC3‐AII displayed conformational restriction because of the TOAC‐imposed bend (Schreier et al., Biopolymers 2004, 74, 389). In HPS, conformational changes were observed for the labeled peptides at neutral and basic pH. In SDS, all peptides underwent pH‐dependent conformational changes. Although the spectra suggested similar folds for AII and TOAC1‐AII, different conformations were acquired by TOAC3‐AII. The membrane environment has been hypothesized to shift conformational equilibria so as to stabilize the receptor‐bound conformation of ligands. The fact that TOAC3‐AII is unable to acquire conformations similar to those of native AII and partially active TOAC1‐AII is probably the explanation for its lack of biological activity. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 525–537, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Salt tolerant membrane adsorbers for robust impurity clearance
Authors: Riordan William T. , Heilmann Steven M. , Brorson Kurt , Seshadri Kannan , Etzel Mark R.
Published: September 2009

Clearance of impurities such as viruses, host cell protein (HCP), and DNA is a critical purification design consideration for manufacture of monoclonal antibody therapeutics. Anion exchange chromatography has frequently been utilized to accomplish this goal; however, anion exchange adsorbents based on the traditional quaternary amine (Q) ligand are sensitive to salt concentration, leading to reduced clearance levels of impurities at moderate salt concentrations (50–150 mM). In this report, membrane adsorbers incorporating four alternative salt tolerant anion exchange ligands were examined for impurity clearance: agmatine, tris‐2‐aminoethyl amine, polyhexamethylene biguanide (PHMB), and polyethyleneimine. Each of these ligands provided greater than 5 log reduction value (LRV) for viral clearance of phage ϕX174 (pI ∼ 6.7) at pH 7.5 and phage PR772 (pI ∼ 4) at pH 4.2 in the presence of salt. Under these same conditions, the commercial Q membrane adsorber provided no clearance (zero LRV). Clearance of host‐cell protein at pH 7.5 was the most challenging test case; only PHMB maintained 1.5 LRV in 150 mM salt. The salt tolerance of PHMB was attributed to its large positive net charge through the presence of multiple biguanide groups that participated in electrostatic and hydrogen bonding interactions with the impurity molecules. On the basis of the results of this study, membrane adsorbers that incorporate salt tolerant anion exchange ligands provide a robust approach to impurity clearance during the purification of monoclonal antibodies. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009
Fermentative Herstellung der α,ω‐Dicarbonsäure 1,18‐Oktadecendisäure als Grundbaustein für biobasierte Kunststoffe
Authors: Zibek S. , Wagner W. , Hirth T. , Rupp S. , Huf S.
Published: September 2009

Langkettige, ungesättigte Dicarbonsäuren stellen interessante Monomere für die Herstellung von neuen Polyamiden und ‐estern dar. Chemisch sind diese nur schwer darstellbar, daher stellt die fermentative Herstellung eine attraktive Alternative dar. Durch Untersuchung von Wachstums‐ und Produktionsparametern konnte der Herstellungsprozess von 1,18‐Oktadecendisäure mit dem Stamm Candida tropicalis verbessert und neue Erkenntnisse gewonnen werden.
N‐(Anilinoethyl)amides: Design and Synthesis of Metabolically Stable, Selective Melatonin Receptor Ligands
Authors: Rivara Silvia , Vacondio Federica , Fioni Alessandro , Silva Claudia , Carmi Caterina , Mor Marco , Lucini Valeria , Pannacci Marilou , Caronno Alessia , Scaglione Francesco , Gobbi Gabriella , Spadoni Gilberto , Bedini Annalida , Orlando Pierfrancesco , Lucarini Simone , Tarzia Giorgio
Published: September 2009

The class of N‐(anilinoethyl)amides includes melatonin receptor ligands with varied subtype selectivity and intrinsic activity. One of these ligands, the MT2‐selective partial agonist UCM765 (N‐{2‐[(3‐methoxyphenyl)phenylamino]ethyl}acetamide), had evidenced hypnotic effects in rodents at doses ≥40 mg kg−1 (s.c.), in spite of its sub‐nanomolar affinity for human melatonin receptors. Supposing that its low in vivo potency could be due, at least in part, to metabolic liability in rat liver, UCM765 was incubated with rat liver S9 fraction and rat, mouse, or human microsomes, and the major metabolites were identified by LC–MS, synthesized, and in vitro tested for their affinity toward MT1 and MT2 receptors. The obtained information was exploited to design novel analogues of UCM765 that are more resistant to in vitro oxidative degradation, while maintaining a similar binding profile. The analogue UCM924 (N‐{2‐[(3‐bromophenyl)‐(4‐fluorophenyl)amino]ethyl}acetamide) displayed a binding profile similar to that of UCM765 on cloned human receptors (MT2‐selective partial agonist) and a significantly longer half‐life in the presence of rat liver S9 fraction.
From the SmA to the Hexatic, Including the SmC*, SmC*Aand SmC*rePhases: A 2H NMR Relaxation Study
Authors: Domenici Valentina , Marini Alberto , Veracini Carlo A. , Malanga Corrado , Menicagli Rita
Published: September 2009

The molecular dynamics of a ferroelectric liquid crystal, denotedZLL 7/*, is investigated by means of2H NMR relaxation. The spin–lattice (T1QandT1Z) and spin–spin (T2) relaxation times of two isotopomers ofZLL 7/*, labeled on the phenyl and biphenyl fragments, are measured and their behavior upon passing from the SmA to the hexatic phase, through the ferroelectric SmC*, antiferroelectric SmC*A, and re‐entrant ferroelectric SmC*rephases, is discussed. A comparison between the measuredT2andT2*, directly related to the experimental linewidth, provides information on the heterogeneity of the system, thus allowing confirmation of previous hypotheses concerning the structural and ordering properties of the SmC*Aand SmC*rephases. The possibility to look at different sites of the core of theZLL 7/*smectogen reveals a peculiar sensitivity of the phenyl moiety with respect to the biphenyl fragment, which may be justified by its vicinity to the chiral centers. Interestingly, the trend of the longitudinal relaxation times is characterized by a minimum that corresponds to the SmC*Aand SmC*rephases, which is reproducible for the two isotopomers and at several Larmor frequencies. A quantitative analysis ofT1QandT1Zis performed in the SmA and SmC* phases, for which the narrowing regime approximation is valid. A multifrequency approach is applied to self‐consistently determine the diffusion coefficients for the overall molecular motions, namely spinning and tumbling, and the internal rotations around theparaaxes of the phenyl and biphenyl fragments. The effect of the magnetic field in unwinding the helical structure of the SmC* phase (forH>9 T) allows observation of a sensitive change in the rotational diffusion coefficients in the frustrated unwound SmC* phase with respect to the SmC* phase.
Strong CH⋅⋅⋅Halide Hydrogen Bonds from 1,2,3‐Triazoles Quantified Using Pre‐Organized and Shape‐Persistent Triazolophanes
Authors: Bandyopadhyay Indrajit , Raghavachari Krishnan , Flood Amar H.
Published: September 2009

The structures associated with halide (F−, Cl−, Br−) complexation inside CH hydrogen‐bonding macrocyclic receptors, called triazolophanes, are characterized using density functional theory (DFT). The associated binding energies in the gas and solution phases are evaluated. The ruffles in the empty triazolophane become smoothed‐out upon Cl−‐ and Br−‐ion binding directly into the middle of the cavity. The largely pre‐organized cavity morphs into an elliptical shape to facilitate shorter hydrogen bonds in the north and south regions and longer ones west and east. The smaller F− ion sits in, and flattens‐out, only the north (or south) region. The 1,2,3‐triazoles show shorter CH⋅⋅⋅Cl− contacts than for the phenylenes. Both Cl− and Br− show the same binding geometries but Cl− has a larger binding energy consistent with its stronger Lewis basicity. Model triads were used to decompose the overall binding energy into those of its components. In the course of this triad analysis, anion polarization was identified and its contribution to the triad⋅⋅⋅Cl− binding energy estimated. Consequently, the binding energies for the individual aryl units within the comparatively non‐polarized triazolophanes were estimated. The 1,2,3‐triazoles are twice as strong as the phenylenes thus contributing most of the interaction energy to Cl−‐ion binding. Therefore, the 1,2,3‐triazoles appear to approach the hydrogen bond strengths of the NH donors of pyrrole units.
The Dodo Bird Verdict—controversial, inevitable and important: a commentary on 30 years of meta‐analyses
Authors: Budd Rick , Hughes Ian
Published: September 2009

In this article, the assertion that different psychological therapies are of broadly similar efficacy—often called the ‘Dodo Bird Verdict’—is contrasted with the alternative view that there are specific therapies that are more effective than others for particular diagnoses. We note that, despite thirty years of meta‐analytic reviews tending to support the finding of therapy equivalence, this view is still controversial and has not been accepted by many within the psychological therapy community; we explore this from a theory of science perspective. It is further argued that the equivalence of ostensibly different therapies is an inevitable consequence of the methodology that has dominated this field of investigation; namely, randomised controlled trials [RCTs]. The implicit assumptions of RCTs are analysed and it is argued that what we know about psychological therapy indicates that it is not appropriate to treat ‘type of therapy’ and ‘diagnosis’ as if they were independent variables in an experimental design. It is noted that one logical consequence of this is that we would not expect RCTs to be capable of isolating effects that are specific to ‘type of therapy’ and ‘diagnosis’. Rather, RCTs would only be expected to be capable of identifying the non‐specific effects of covariates, such as those of therapist allegiance. It is further suggested that those non‐specific effects that have been identified via meta‐analysis are not trivial findings, but rather characterise important features of psychological therapy. Copyright © 2009 John Wiley & Sons, Ltd.
Mokken scaling and principal components analyses of the CORE‐OM in a large clinical sample
Authors: Bedford A. , Watson R. , Lyne J. , Tibbles J. , Davies F. , Deary I. J.
Published: September 2009

In a sample of 543 adult National Health Service (NHS) patients referred to a Psychological Therapies Service, the responses to the Clinical Outcomes in Routine Evaluation‐Outcome Measure (CORE‐OM) self‐report questionnaire were examined using conventional principal components analysis (PCA) and a unique application of Mokken Scaling Procedure (MSP). Following the theoretical views of G. A. Foulds, it was suggested that some items more properly belong to the universe of attitudes and traits rather than that of symptoms and states. Accordingly, the analyses were carried out both with and without the CORE‐OM Risk domain items. Both PCAs produced a very large first component of Psychological distress, while the small second component differs. With all items included, the second component was of Risk. With the risk items excluded, the second component was now Functioning. The MSP results, respectively, were of a five‐item scale of Functioning (impaired by depression) and on the second analysis, a five‐item Functioning scale (impaired by anxiety). There was discussion on the criteria for item selection, the time scale specified in questionnaire instructions and the optimum number of items required for a symptom scale. It was concluded that the CORE‐OM item pool did not conform to its purported face validity domains and subdomains, but predominantly constitutes a large Psychological distress scale with considerable item redundancy. Copyright © 2009 John Wiley & Sons, Ltd.
PolyI:C plus IL‐2 or IL‐12 induce IFN‐γ production by human NK cells via autocrine IFN‐β
Authors: Duluc Dorothée , Tan Fang , Scotet Mari , Blanchard Simon , Frémaux Isabelle , Garo Erwan , Horvat Branka , Eid Pierre , Delneste Yves , Jeannin Pascale
Published: September 2009

NK lymphocytes and type I IFN (IFN‐α/β) are major actors of the innate anti‐viral response that also influence adaptive immune responses. We evaluated type I IFN production by human NK cells in response to polyI:C, a potent type I IFN‐inducing TLR3 agonist. PolyI:C plus IL‐2/IL‐12 induced IFN‐β (but not IFN‐α) mRNA expression and protein production by highly pure human NK cells and by the human NK cell line NK92. Neutralizing anti‐IFNAR1 or anti‐IFN‐β Ab prevented the production of IFN‐γ induced by polyI:C plus IL‐2/IL‐12. Similarly, IFN‐γ production induced by polyI:C plus IL‐12 was reduced in NK cells isolated from IFNAR1−/− compared with WT mice. The ability of polyI:C plus IL‐12 to induce IFN‐γ production was related to an increase of TLR3, Mda5 and IFNAR expression and by an increase of STAT1 and STAT4 phosphorylation. Collectively, these data demonstrate that NK cells, in response to polyI:C plus IL‐2/IL‐12, produce IFN‐β that induce, in an autocrine manner, the production of IFN‐γ and thereby highlight that NK cells may control the outcome of protective or injurious immune responses through type I IFN secretion.
Concurrent infection with Heligmosomoides polygyrus suppresses anti‐Plasmodium yoelii protection partially by induction of CD4+CD25+Foxp3+ Treg in mice
Authors: Tetsutani Kohhei , Ishiwata Kenji , Ishida Hidekazu , Tu Liping , Torii Motomi , Hamano Shinjiro , Himeno Kunisuke , Hisaeda Hajime
Published: September 2009

Malaria and intestinal nematode infection are widespread and co‐infection frequently occurs. We investigated whether co‐infected intestinal nematodes modulate immunity against co‐existing malaria parasites. Infection of C57BL/6 mice with Plasmodium yoelii 17XNL (Py) was transient and self‐limiting, but preceding infection with Heligmosomoides polygyrus (Hp), a mouse intestinal nematode, exacerbated malaria resulting in higher parasite burdens and poor survival of the mice. Co‐infection with Hp led to reduced Py‐responsive proliferation and IFN‐γ production of spleen cells, and higher activation of CD4+CD25+Foxp3+ Treg. In vivo depletion of Treg recovered anti‐Py immunity and rescued co‐infected mice from exacerbated malaria. However, we did not observe any obvious ex vivo activation of Treg by either Hp products or living worms. Our results suggest that intestinal nematodes moderate host immune responses during acute malaria infection by aggressive activation of Treg. Elucidation of the mechanisms of Treg activation in situ is a target for future analyses.
Role of DOCK2 and DOCK180 in fetal thymus colonization
Authors: Lei Yu , Liu Cunlan , Saito Fumi , Fukui Yoshinori , Takahama Yousuke
Published: September 2009

Fetal thymus colonization is initiated before the vascularization of the thymus primordium. This prevascular colonization of the fetal thymus by T‐lymphoid progenitor cells is guided by the coordination of CCR7‐ and CCR9‐mediated chemokine signals. However, the intracellular signals that mediate the prevascular migration of T‐lymphoid progenitor cells to the fetal thymus are unknown. Here we show that T‐lymphoid progenitor cells in fetal mice express two closely related CDM family molecules, DOCK2 and DOCK180. We found that the prevascular fetal thymus accumulation in vivo was significantly reduced in mice doubly deficient for DOCK2 and DOCK180 but not in mice deficient for either DOCK2 or DOCK180. Immature T‐lymphoid cells from mice doubly deficient for DOCK2 and DOCK180 were defective in their in vitro migration towards fetal thymus lobes. The T‐lymphoid progenitor cells generated in mice lacking DOCK2 and DOCK180 were capable of T‐cell development after their transfer into a fetal thymus environment, and the impaired fetal thymus colonization in mice deficient for DOCK2 and DOCK180 was not as severe as that in mice doubly deficient for CCR7 and CCR9. These results indicate that the combination of DOCK2 and DOCK180 plays a significant but not essential role in prevascular fetal thymus colonization.
Monocyclopentadienyl(niobium) Compounds with Imido and Silsesquioxane Ligands: Synthetic, Structural and Reactivity Studies
Authors: García Carlos , Gómez Manuel , Gómez‐Sal Pilar , Hernández José Manuel
Published: September 2009

A new half‐sandwich imido compound, [Nb{η5‐C5H3(SiMe3)2}Cl2(NtBu)] (1), was isolated by treatment of [Nb{η5‐C5H3(SiMe3)2}Cl4] with 1 equiv. LiNHtBu in hexane. Alkylimido derivatives [Nb{η5‐C5H3(SiMe3)2}RR′(NtBu)] (R = Cl, R′ = Me 2; R = R′ = Me 3, CH2SiMe3 4) can be prepared by reaction of 1 with the appropriate alkylating reagent. Silsesquioxane ligand [Si8O12Cl(iBu)7] (5a) can be obtained by treatment of [Si7O9(OH)3(iBu)7] with 1 equiv. silicon tetrachloride in the presence of triethylamine. Ligand 5a reacts with NH3 (g) at low temperatures to yield an amido derivative, [Si8O12(NH2)(iBu)7] (5b), whereas the reaction of the trisilanol with excess BuLi leads to the corresponding lithium salt [Li3Si7O12(iBu)7] (5c). A dichlorido(silsesquioxanylimido)niobium compound [Nb{η5‐C5H3(SiXMe2)(SiMe3)}Cl2{NSi8O12(iBu)7}] (X = Cl 6a, Me 6b) can be prepared by reaction of 1 equiv. tetrachloridoniobium complex [Nb{η5‐C5H3(SiXMe2)(SiMe3)}Cl4] (X = Cl, Me) and amidosilsesquioxane 5b. From 6b, three new alkyl derivatives, [Nb{η5‐C5H3(SiMe3)2}XY(NSi8O12R7)] (R = iBu, X = Cl, Y = Me 7; X = Y = Me 8, CH2SiMe3 9), were isolated by usual alkylation reactions. Alternatively, protonolysis reaction of trisilanol [Si7O9R7(OH)3] with [Nb{η5‐C5H3(SiXMe2)(SiMe3)}Cl4] (X = Cl) in the presence of triethylamine produces a dichlorido derivative, [Nb{η5‐C5H3(SiMe3)(Me2SiOSi7O11R7‐κ2O,O)}Cl2] (R = iBu 10), which can be transformed into an imido complex, [Nb{η5‐C5H3(SiMe3)(Me2SiOSi7O11R7‐κ2O,O)}(NtBu)] (R = iBu 11), by reaction with LiNHtBu, whereas for X = Me, a chlorido complex, [Nb{η5‐C5H3(SiMe3)2}Cl(Si7O12R7‐κ3O,O,O)] (R = iBu 12), can be isolated. Alkylation of 10 and 12 leads to dimethyl, trimethylsilylmethylidene and methyl derivatives 13, 14 and 15, respectively. Alkylimidoniobium complexes 2–4 react with carbon monoxide or xylyl isocyanide at room temperature to give acylimidoniobium [Nb{η5‐C5H3(SiMe3)2}R(NtBu){C(R′)O‐κ2C,O}] (R = Cl, R′ = Me 16; R = R′ = Me 17, CH2SiMe3 18) and iminoacylimidoniobium [Nb{η5‐C5H3(SiMe3)2}R(NtBu){C(Me)NAr‐κ2C,N}] (Ar = 2,6‐Me2C6H3; R = Cl 21, Me 22) compounds by simple insertion reactions. However, compound 13 reacts with CO and 2,6‐Me2C6H3NC, leading to enediolato [Nb{η5‐C5H3(SiMe3)(Me2SiOSi7O11R7‐κ2O,O)}{O(Me)C=C(Me)O‐κ2O,O}] (R = iBu 19) and azaniobacyclopropane [Nb{η5‐C5H3(SiMe3)(Me2SiOSi7O11R7‐κ2O,O)}(CMe2NAr‐κ2C,N)] (R = iBu, Ar = 2,6‐Me2C6H3 20) derivatives through intermolecular coupling between two acyl groups and by a double methyl migration processes, respectively. All new compounds have been characterized by IR spectrophotometry, 1H, 13C{1H} and 29Si{1H} NMR spectroscopy and elemental analysis.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Determination of thyreostatics in animal feeds by CE with electrochemical detector
Authors: Kong Dexian , Chi Yuwu , Chen Lichan , Dong Yongqiang , Zhang Lan , Chen Guonan
Published: September 2009

A simple, rapid, reproducible and sensitive method based on CE with electrochemical detector was developed for the simultaneous determination of five thyreostatics including 2‐thiouracil (TU), 6‐methyl‐2‐thiouracil (MTU), 6‐propyl‐2‐thiouracil (PTU), 6‐phenyl‐2‐thiouracil (PhTU) and methimazole (TAP) in animal feeds. A home‐made wall‐jet electrochemical detector with a 300 μm diameter platinum‐disk‐working electrode was equipped at the end of separation capillary and used to detect oxidation currents of these thyreostatics. Under the optimum experimental conditions, TU, MTU, PTU, PhTU and TAP could be well separated within 15 min at the separation voltage of 16 kV in 20 mmol/L sodium borate buffer (pH 9.2). The detection limits (S/N=3) of the five thyreostatics in animal feeds were found to be 7.6 μg/kg for TAP, 25 μg/kg for PTU, 15 μg/kg for PhTU, 18 μg/kg for TU and 20 μg/kg for MTU by the developed CE with electrochemical detector method coupled with solid‐phase extraction sample pretreatment technique.
Carbon nanotube/poly(ethylene‐co‐vinyl acetate) composite electrode for capillary electrophoretic determination of esculin and esculetin in Cortex Fraxini
Authors: Chen Zhi , Zhang Luyan , Chen Gang
Published: September 2009

In this report, a novel carbon nanotube/poly(ethylene‐co‐vinyl acetate) (CNT/EVA) composite electrode was developed for the amperometric detection in CE. The composite electrode was fabricated by packing a mixture of CNTs and melted EVA in a piece of fused‐silica capillary under heat. It was coupled with CE for the separation and detection of esculin and esculetin in Cortex Fraxini, a traditional Chinese medicine, to demonstrate its feasibility and performance. Esculin and esculetin have been well separated within 9 min in a 40 cm long capillary at a separation voltage of 12 kV using a 50 mM borate buffer (pH 9.2). The new CNT‐based CE detector offered significantly lower detection potentials, yielded enhanced S/N characteristics, and exhibited high resistance to surface fouling and enhanced stability. It showed long‐term stability and reproducibility with relative standard deviations of less than 5% for the peak current (n=15) and should also find a wide range of applications in other microfluidic analysis systems.
Predicting intra‐urban variation in air pollution concentrations with complex spatio‐temporal dependencies
Authors: Szpiro Adam A. , Sampson Paul D. , Sheppard Lianne , Lumley Thomas , Adar Sara D. , Kaufman Joel D.
Published: September 2009

We describe a methodology for assigning individual estimates of long‐term average air pollution concentrations that accounts for a complex spatio‐temporal correlation structure and can accommodate spatio‐temporally misaligned observations. This methodology has been developed as part of the Multi‐Ethnic Study of Atherosclerosis and Air Pollution (MESA Air), a prospective cohort study funded by the US EPA to investigate the relationship between chronic exposure to air pollution and cardiovascular disease. Our hierarchical model decomposes the space‐‐time field into a “mean” that includes dependence on covariates and spatially varying seasonal and long‐term trends and a “residual” that accounts for spatially correlated deviations from the mean model. The model accommodates complex spatio‐temporal patterns by characterizing the temporal trend at each location as a linear combination of empirically derived temporal basis functions, and embedding the spatial fields of coefficients for the basis functions in separate linear regression models with spatially correlated residuals (universal kriging). This approach allows us to implement a scalable single‐stage estimation procedure that easily accommodates a significant number of missing observations at some monitoring locations. We apply the model to predict long‐term average concentrations of oxides of nitrogen (NOx) from 2005 to 2007 in the Los Angeles area, based on data from 18 EPA Air Quality System regulatory monitors. The cross‐validated IR2 is 0.67. The MESA Air study is also collecting additional concentration data as part of a supplementary monitoring campaign. We describe the sampling plan and demonstrate in a simulation study that the additional data will contribute to improved predictions of long‐term average concentrations. Copyright © 2009 John Wiley & Sons, Ltd.