bluuebunny/crossref_metadata_2025 huggingface dataset:
A New Luminescent Ruthenium(II) Polypyridine‐derived Dipicolylamine Complex as a Sensor for Cu2+ Ions
Authors: Li Xianghong , Chen Yuanbing , Meng Jiahe , Lü Kangle , Zhang Aiqing , Zhang Bingguang
Published: September 2011

A chemo‐sensor [Ru(bpy)2(bpy‐DPF)](PF6)2 (1) (bpy=2,2′‐bipyridine, bpy‐DPF=2,2′‐bipyridyl‐4,4′‐bis(N,N‐di(2‐picolyl))formylamide) for Cu2+ using di(2‐picolyl)amine (DPA) as the recognition group and a ruthenium(II) complex as the reporting group was synthesized and characterized successfully. It demonstrates a high selectivity and efficient signaling behavior only for Cu2+ with obvious red‐shifted MLCT (metal‐to‐ligand charge transfer transitions) absorptions and dramatic fluorescence quenching compared with Zn2+ and other metal ions.
Emission Color Tuning with Polymer Molecular Weight for Dyes of 4‐Dicyanomethylene‐2‐methyl‐6‐{4‐[(2‐hydroxyethyl)(methyl)amino]styryl}‐4H‐pyran
Authors: Zhang Jinfeng , Wu Jincai
Published: September 2011

A series of novel polylactide (PLA) polymers were synthesized initiated by 4‐dicyanomethylene‐2‐methyl‐6‐{4‐[(2‐hydroxyethyl)(methyl)amino]styryl}‐4H‐pyran (DCM) with Sn(Oct)2 as catalyst. The color and emission of the polymer can be tuned just with polymer molecular weight.
Ab initio Study of Mechanism of Cycloaddition Reaction between Germylene Silylene (H2GeSi:) and Acetone
Authors: Lu Xiuhui , Han Junfeng , Li Yongqing , Wang Zhina
Published: September 2011

The mechanism of the cycloaddition reaction between singlet germylene silylene (H2GeSi:) and acetone has been investigated with CCSD(T)/6‐31G*//MP2/6‐31G* method. From the potential energy profile, we could predict that the reaction has two competitive dominant reaction channels. The present rule of this reaction is that the [2+2] cycloaddition reaction of the two (‐bonds in germylene silylene and acetone generates a four‐membered ring silylene with Ge. Because of the unsaturated property of Si atom in the four‐membered ring silylene with Ge, it could further react with acetone, resulting in the generation of a bis‐heterocyclic compound with Si and Ge. Simultaneously, the ring strain of the four‐membered ring silylene with Ge makes it isomerize to a twisted four‐membered ring product.
Intercomparison of performance of RF coil geometries for high field mouse cardiac MRI
Authors: Constantinides Christakis , Angeli S. , Gkagkarellis S. , Cofer G.
Published: September 2011

Multiturn spiral surface coils are constructed in flat and cylindrical arrangements and used for high field (7.1 T) mouse cardiac MRI. Their electrical and imaging performances, based on experimental measurements, simulations, and MRI experiments in free space, and under phantom, and animal loading conditions, are compared with a commercially available birdcage coil. Results show that the four‐turn cylindrical spiral coil exhibits improved relative SNR (rSNR) performance to the flat coil counterpart, and compares fairly well with a commercially available birdcage coil. Phantom experiments indicate a 50% improvement in the SNR for penetration depths ≤6.1 mm from the coil surface compared to the birdcage coil, and an increased penetration depth at the half‐maximum field response of 8 mm in the four‐spiral cylindrical coil case, in contrast to 2.9 mm in the flat four‐turn spiral case. Quantitative comparison of the performance of the two spiral coil geometries in anterior, lateral, inferior, and septal regions of the murine heart yield maximum mean percentage rSNR increases of the orderof 27–167% in vivo postmortem (cylindrical compared to flat coil). The commercially available birdcage outperforms the cylindrical spiral coil in rSNR by a factor of 3–5 times. The comprehensive approach and methodology adopted to accurately design, simulate, implement, and test radiofrequency coils of any geometry and type, under any loading conditions, can be generalized for any application of high field mouse cardiac MRI. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38: 236–252, 2011.
Biomolecular surface construction by PDE transform
Authors: Zheng Qiong , Yang Siyang , Wei Guo‐Wei
Published: September 2011

This work proposes a new framework for the surface generation based on the partial differential equation (PDE) transform. The PDE transform has recently been introduced as a general approach for the mode decomposition of images, signals, and data. It relies on the use of arbitrarily high‐order PDEs to achieve the time–frequency localization, control the spectral distribution, and regulate the spatial resolution. The present work provides a new variational derivation of high‐order PDE transforms. The fast Fourier transform is utilized to accomplish the PDE transform so as to avoid stringent stability constraints in solving high‐order PDEs. As a consequence, the time integration of high‐order PDEs can be done efficiently with the fast Fourier transform. The present approach is validated with a variety of test examples in two‐dimensional and three‐dimensional settings. We explore the impact of the PDE transform parameters, such as the PDE order and propagation time, on the quality of resulting surfaces. Additionally, we utilize a set of 10 proteins to compare the computational efficiency of the present surface generation method and a standard approach in Cartesian meshes. Moreover, we analyze the present method by examining some benchmark indicators of biomolecular surface, that is, surface area, surface‐enclosed volume, solvation free energy, and surface electrostatic potential. A test set of 13 protein molecules is used in the present investigation. The electrostatic analysis is carried out via the Poisson–Boltzmann equation model. To further demonstrate the utility of the present PDE transform‐based surface method, we solve the Poisson–Nernst–Planck equations with a PDE transform surface of a protein. Second‐order convergence is observed for the electrostatic potential and concentrations. Finally, to test the capability and efficiency of the present PDE transform‐based surface generation method, we apply it to the construction of an excessively large biomolecule, a virus surface capsid. Virus surface morphologies of different resolutions are attained by adjusting the propagation time. Therefore, the present PDE transform provides a multiresolution analysis in the surface visualization. Extensive numerical experiment and comparison with an established surface model indicate that the present PDE transform is a robust, stable, and efficient approach for biomolecular surface generation in Cartesian meshes. Copyright © 2011 John Wiley & Sons, Ltd.
A Theoretical Study of the 3d‐M(smif)2Complexes: Structure, Magnetism, and Oxidation States
Authors: Hachmann Johannes , Frazier Brenda A. , Wolczanski Peter T. , Chan Garnet Kin‐Lic
Published: September 2011

We carry out a theoretical investigation of the recently reported M(smif)2series1, 2and find a number of interesting phenomena. These include complex potential energy surfaces with near‐degenerate stationary points, low‐lying states, non‐trivial electron configurations, as well as non‐innocent ligand behavior. The M(smif)2exhibit a delicate balance between geometry and electronic structure, which has implications not only for their reactivity but also for controlling their properties through ligand design. We address methodological issues and show how conceptual quantities such as oxidation states and electronic configurations can be extracted through a simple analysis of the electron and spin densities—without a complicated examination of the underlying orbitals.
The Resonance Raman Spectra of Spheroidene Revisited with a First‐Principles Approach
Authors: Boereboom Jelle M. , van Hemert Marc C. , Neugebauer Johannes
Published: September 2011

The resonance Raman (RR) spectra of different configurations of spheroidene are calculated by means of quantum chemical methods to investigate the nature of the cis configuration of this carotenoid molecule in the photosynthetic reaction center (RC) of the purple bacterium Rhodobacter sphaeroides. For validation of our methodology, we also calculate the spectrum of the all‐trans structure present in the light‐harvesting complexes of this bacterium. While former theoretical resonance Raman studies only considered truncated models of spheroidene, we report on calculations employing the full pigment here. The calculated frequencies for the all‐trans configuration are in good agreement with former experimental and simulated data. Among the possible cis structures, the 15,15′‐cis configuration shows a RR spectrum that is in best agreement with the experimental spectrum of spheroidene in the RC. In order to assess model truncation effects, we compare calculations for the full spheroidene molecule to those for the truncated model. While the main features can already be found in the latter, the full model leads to considerably different intensities in the region around 1150 cm−1, which improve the agreement with experiment. A slight mismatch for the vibrational frequencies in the CC stretch region is investigated by considering a model for spheroidene in the binding pocket comprising more than 500 atoms in total. The results do not lead to improved agreement with experiment, in contrast to the simpler strategy of introducing constraints in the structural optimization of a truncated spheroidene model. The calculated RR spectrum of the 13,14‐cis configuration shows additional features which can also be identified in the experimental RR spectrum. This shows that the most likely cis structure is the 15,15′‐cis configuration. Besides this, the 13,14‐cis configuration remains a candidate for an additional spheroidene structure in the RC of Rhodobacter sphaeroides mutant R26.
Improved flow cytometric detection of ZAP‐70 in chronic lymphocytic leukemia using experimentally optimized isotypic control antibodies
Authors: Preobrazhensky Sergey N. , Szankasi Philippe , Bahler David W.
Published: September 2011

Introduction:

Expression of ZAP‐70 by chronic lymphocytic leukemia (CLL) is associated with more aggressive disease and can help differentiate CLL using mutated immunoglobulin heavy chain variable genes (VH) from cases expressing unmutated VH genes. However, flow cytometric detection of ZAP‐70 in CLL shows considerable variability and may be of questionable significance because most laboratories cannot correlate their results to clinical outcome or VH mutational data.

Methods:

Seventy cases of CLL were evaluated for ZAP‐70 using a previously optimized staining procedure and two different methods to eliminate nonspecific background staining. One method, not previously reported, used isotypic control antibodies, where the concentrations were adjusted/optimized so that normal B‐cells stained negatively for ZAP‐70. The other used ZAP‐70 stained peripheral blood B‐cells from normal donors. The percentages of ZAP‐70 stained CLL cells above the two thresholds were compared.

Results:

Concentrations of isotypic control antibodies had to be increased from manufacture's recommendations to insure normal B‐cells were ZAP‐70 negative. ZAP‐70 levels among the CLL cases formed a bimodal distribution using the optimized isotypic control threshold, with 30 having low values (0–32% positive) and 40 high values (60–99% positive). In contrast, a continuous distribution was obtained with the ZAP‐70 stained B‐cell threshold. VH mutational status strongly correlated with the optimized control values as 29/30 low ZAP‐70 cases had mutated VH genes and 37/40 high ZAP‐70 cases used unmutated VH genes.

Conclusions:

Use of an optimized isotypic control threshold could increase the reliability of flow based ZAP‐70 detection and correlates well with VH mutational status. © 2011 International Clinical Cytometry Society
Haptic processing in newborns of depressed and nondepressed mothers
Authors: Jouen François , Sann Coralie , Molina Michèle
Published: September 2011

This study was conducted to compare how newborns of depressed mothers and newborns of nondepressed mothers gather tactile information about texture. Spontaneous manual activity on objects with a smooth or rough texture was recorded in 20 newborns born of mothers with a high risk of depression or a low risk of depression. An important result of the present study is that texture‐based modulation of hand‐pressing frequency was observed in both neonates born of depressed mothers and neonates born of nondepressed mothers. Moreover, hand‐pressing frequency did not depend on the pressure exerted on the object, since all neonates displayed comparable pressure on the held object. Lastly, the results revealed that newborns of depressed mothers held the rough object twice as long as newborns of nondepressed mothers. These results are analyzed in reference to deregulated biochemical functions in neonates born of mothers with a high risk of depression. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:451–459, 2012.
Nerve growth factor induces cell cycle arrest of astrocytes
Authors: Cragnolini Andrea B. , Volosin Marta , Huang Yangyang , Friedman Wilma J.
Published: September 2011

Neurotrophins can influence multiple cellular functions depending on the cellular context and the specific receptors they interact with. These neurotrophic factors have been extensively studied for their ability to support neuronal survival via Trk receptors and to induce apoptosis via the p75NTR. However, the p75NTR is also detected on cell populations that do not undergo apoptosis in response to neurotrophins. In particular, the authors have detected p75NTR expression on astrocytes during development and after seizure‐induced injury. In this study, the authors investigated the role of Nerve growth factor (NGF) in regulating astrocyte proliferation and in influencing specific aspects of the cell cycle. The authors have demonstrated that NGF prevents the induction of cyclins and their association with specific cyclin‐dependent kinases, and thereby prevents progression through the G1 phase of the cell cycle. Since the authors have previously shown that p75NTR but not TrkA, is expressed in astrocytes, these data suggest that activation of p75NTR promotes withdrawal of astrocytes from the cell cycle, which may have important consequences during development and after injury. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 766–776, 2012
Live imaging of endogenous periodic tryptophan protein 2 gene homologue during zebrafish development
Authors: Jayasena Chathurani S. , Trinh Le A. , Bronner Marianne
Published: September 2011

Yeast Periodic tryptophan protein 2 gene (Pwp2) is involved in ribosome biogenesis and has been implicated in regulation of the cell cycle in yeast. Here, we report a zebrafish protein‐trap line that produces fluorescently tagged Periodic tryptophan protein 2 gene homologue (Pwp2h) protein, which can be dynamically tracked in living fish at subcellular resolution. We identified both full‐length zebrafish Pwp2h and a short variant. The expression results show that Pwp2h is present in numerous sites in the early developing embryo, but later is restricted to highly proliferative regions, including the forebrain ventricular zone and endoderm‐derived organs in the early larval stage. At the subcellular level, Pwp2h protein appears to be localized to the region of the nucleolus consistent with its presumed function in ribosomal RNA synthesis. This Pwp2h protein trap line offers a powerful tool to study the link between ribosome biogenesis and cell cycle progression during vertebrate development. Developmental Dynamics 240:2578–2583, 2011. © 2011 Wiley Periodicals, Inc.
Tissue interaction is required for glenoid fossa development during temporomandibular joint formation
Authors: Wang Ying , Liu Chao , Rohr Joseph , Liu Hongbing , He Fenglei , Yu Jian , Sun Cheng , Li Lu , Gu Shuping , Chen YiPing
Published: September 2011

The mammalian temporomandibular joint (TMJ) develops from two distinct mesenchymal condensations that grow toward each other and ossify through different mechanisms, with the glenoid fossa undergoing intramembranous ossification while the condyle being endochondral in origin. In this study, we used various genetically modified mouse models to investigate tissue interaction between the condyle and glenoid fossa during TMJ formation in mice. We report that either absence or dislocation of the condyle results in an arrested glenoid fossa development. In both cases, glenoid fossa development was initiated, but failed to sustain, and became regressed subsequently. However, condyle development appears to be independent upon the presence of the forming glenoid fossa. In addition, we show that substitution of condyle by Meckel's cartilage is able to sustain glenoid fossa development. These observations suggest that proper signals from the developing condyle or Meckel's cartilage are required to sustain the glenoid fossa development. Developmental Dynamics 240:2466–2473, 2011. © 2011 Wiley‐Liss, Inc.
Cognitive Profiles of Korean Poor Readers
Authors: Cho Jeung‐Ryeul , Ji Yu‐Kyong
Published: September 2011

This study compared the performance of 30 poor readers in the third grade with those of 30 average readers of the same age and 30 younger readers matched with the same reading level on phonological, visuo‐perceptual, orthographic, and naming speed tasks. Individual data revealed heterogeneous profiles for the poor readers: six (20%) exhibited visual deficit; two (6.7%) had a single phonological deficit; and six (20%) had a double phonological and visual deficit. A naming speed deficit appeared, not as a single type, but in association with a phonological deficit (23.3%), a visual deficit (3.3%), or both (10%). These results suggest that Koreans' most significant reading problems lie in phonological awareness and in visual and naming speed processing. In particular, phonological and visual deficits are major independent risk factors in Korean reading impairments. Copyright © 2011 John Wiley & Sons, Ltd.
CD4+Foxp3+ regulatory T cells suppress γδ T‐cell effector functions in a model of T‐cell‐induced mucosal inflammation
Authors: Yurchenko Ekaterina , Levings Megan K. , Piccirillo Ciriaco A.
Published: September 2011

CD4+CD25+Foxp3+ regulatory T (TREG) cells are critical mediators of peripheral immune tolerance, and abrogation of their function provokes a variety of autoimmune and inflammatory states including inflammatory bowel disease. In this study, we investigate the functional dynamics of TREG‐cell responses in a CD4+ T‐cell‐induced model of intestinal inflammation in αβ T‐cell‐deficient (TCR‐β−/−) hosts to gain insights into the mechanism and cellular targets of suppression in vivo. We show that CD4+ T effector cell transfer into T‐cell‐deficient mice rapidly induces mucosal inflammation and colitis development, which is associated with prominent Th1 and Th17 responses. Interestingly, we unveil a prominent role for resident γδ T cells in mucosal inflammation as they promote Th1 and particularly Th17 responses in the early phase of inflammation, thus exacerbating colitis development. We further demonstrate that CD4+CD25+Foxp3+ TREG cells readily inhibit these responses and mediate disease protection, which correlates with their accumulation in the draining LN and lamina propria. Moreover, TREG cells can directly suppress γδ T‐cell expansion and cytokine production in vitro and in vivo, suggesting a pathogenic role of γδ T cells in intestinal inflammation. Thus, functional alterations in TREG cells provoke dysregulated CD4+ and γδ T‐cell responses to commensal antigens in the intestine.
Recording the Reaction Process of Loop‐Mediated Isothermal Amplification (LAMP) by Monitoring the Voltammetric Response of 2′‐Deoxyguanosine 5′‐Triphosphate
Authors: Zhang Xuzhi , Qu Keming , Li Qiufen , Cui Zhengguo , Zhao Jun , Sun Xuemei
Published: September 2011

We describe here a novel strategy for recording the reaction process of loop‐mediated isothermal amplification (LAMP) by monitoring the voltammetric response of 2′‐deoxyguanosine 5′‐triphosphate (dGTP). Unlike the other three kinds of reactive substrates for DNA synthesis in LAMP reaction, dGTP exhibits sensitive voltammetric response at the carbon nanotube array electrode. When the LAMP reaction occurs, the concentration of dGTP decreases accordingly, bringing forth the decrease of the anodic peak current (ipa). In inversion, the decrease of the ipa of dGTP was used to characterize the reaction process of LAMP. The relationships among the LAMP reaction time, the initial quantity of template DNA and the value change of the ipa were studied. The results indicate that the protocol integrated LAMP and voltammetric techniques can be used for not only qualitative gene discrimination but also quantitative gene assay in a wide range. The malB gene extracted from common strains of Escherichia coli cells was tested as a model. The detecting results of LAMPs obtained by voltammetric method were in good agreement with those by optical‐based methods (gel electrophoresis and fluorescent dye).
Ion‐Selective Electrodes – The Early Years
Authors: Durst Richard A.
Published: September 2011

As we near the 50th anniversary of the development of modern ion‐selective electrodes (ISEs), the Matrafüred Conference seemed to be the ideal venue to reminisce about the early years, since Hungary is generally regarded as the birthplace of these new electrodes. Those of us, who worked with ISEs in the 1960s and ′70s, can recall the excitement of discovery existing at the time. In this reminiscence, I shall first provide a few vignettes of the leaders in the early years followed by a description of some of my personal research to demonstrate the variety of novel approaches open to investigators of that era.
Peptide mapping using capillary electrophoresis offline coupled to matrix‐assisted laser desorption ionization time of flight mass spectrometry
Authors: Bachmann Stefan , Bakry Rania , Huck Christian W. , Polato Fabio , Corradini Danilo , Bonn Günther K.
Published: September 2011

This article reports the results of a study carried out to evaluate the offline hyphenation of capillary zone electrophoresis with matrix‐assisted lased desorption ionization time of flight mass spectrometry (MALDI‐TOF‐MS) for the analysis of low‐abundant complex samples, represented by the tryptic phosphorylated peptides of phosphoproteins, such as α‐casein, β‐casein, and fetuin. The proposed method employs a latex‐coated capillary and consists in the online preconcentration of the tryptic peptides by a pH‐mediated stacking method, their separation by capillary zone electrophoresis, and subsequent deposition of the separated analytes onto a MALDI target for their MS analysis. The online preconcentration method allows loading a large sample volume (∼150 nL), which is introduced into the capillary after the hydrodynamic injection of a short plug of 1.0 M ammonium hydroxide solution and is sandwiched between two plugs of the acidic background electrolyte solution (BGE) filling the capillary. The sample spotting of the separated analytes onto the MALDI target is performed either during or postseparation using an automatic spotting device connected to the exit of the separation capillary. The proposed method allows the separation and identification of multiphosphorylated peptides from other peptides and enables their identification at femtomole level with improved efficiency compared with LC approaches hyphenated to MS.
Seismic design and hybrid tests of a full‐scale three‐story buckling‐restrained braced frame using welded end connections and thin profile
Authors: Lin Pao‐Chun , Tsai Keh‐Chyuan , Wang Kung‐Juin , Yu Yi‐Jer , Wei Chih‐Yu , Wu An‐Chien , Tsai Ching‐Yi , Lin Chih‐Han , Chen Jia‐Chian , Schellenberg Andreas H. , Mahin Stephen A. , Roeder Charles W.
Published: September 2011

A series of hybrid and cyclic loading tests were conducted on a three‐story single‐bay full‐scale buckling‐restrained braced frame (BRBF) at the Taiwan National Center for Research on Earthquake Engineering in 2010. Six buckling‐restrained braces (BRBs) including two thin BRBs and four end‐slotted BRBs, all using welded end connection details, were installed in the frame specimen. The BRBF was designed to sustain a design basis earthquake in Los Angeles. In the first hybrid test, the maximum inter‐story drift reached nearly 0.030 rad in the second story and one of the thin BRBs in the first story locally bulged and fractured subsequently before the test ended. After replacing the BRBs in the first story with a new pair, a second hybrid test with the same but reversed direction ground motion was applied. The maximum inter‐story drifts reached more than 0.030 rad and some cracks were found on the gusset welds in the second story. The frame responses were satisfactorily predicted by both OpenSees and PISA3D analytical models. The cyclic loading test with triangular lateral force distribution was conducted right after the second hybrid test. The maximum inter‐story drift reached 0.032, 0.031, and 0.008 rad for the first to the third story, respectively. This paper then presents the findings on the local bulging failure of the steel casing by using cyclic test results of two thin BRB specimens. It is found that the steel casing bulging resistance can be computed from an equivalent beam model constructed from the steel core plate width and restraining concrete thickness. This paper concludes with the recommendations on the seismic design of thin BRB steel casings against local bulging failure. Copyright © 2011 John Wiley & Sons, Ltd.
An experimental and numerical investigation on the cyclic response of a portal frame pier belonging to an old reinforced concrete viaduct
Authors: Paolacci F. , Giannini R.
Published: September 2011

This paper deals with the assessment of the seismic response of a portal frame pier belonging to an old reinforced concrete viaduct. A series of tests, consisting of cyclically imposed displacements, were carried out on three 1:4 scale mock‐ups. The objective of the experimental campaign is twofold: (1) identification and evaluation of the local failure mechanisms and (2) calibration of a numerical model including all observed nonlinear phenomena. The experimental results show that the shear strength of the transverse beam and of the beam–column joints characterizes the post‐elastic behavior of the piers. Other phenomena, like bond‐slip and buckling of the longitudinal bars of the columns, typical of old reinforced concrete structures have also been observed. Finally, a numerical model, built in OpenSEES, was calibrated to reproduce in a satisfactory way the experimental results and to provide a reliable tool for the evaluation of the seismic response of the pier. Copyright © 2011 John Wiley & Sons, Ltd.
Reproduction of aquatic hyphomycetes at low concentrations of Ca2+, Zn2+, Cu2+, and Cd2+
Authors: Sridhar Kandikere R , Bärlocher Felix
Published: September 2011

Maple leaf disks were conditioned in a stream for three weeks and then aerated for 2 d in distilled water to induce fungal sporulation. The release of aquatic hyphomycete spores increased when the water was supplemented with low concentrations of Ca2+ (5 µg/L), Zn2+ (2.5 µg/L), Cu2+ (0.5 µg/L), or Cd2+ (0.125 µg/L). Higher supplement concentrations inhibited sporulation. Over the concentration range used, the sporulation response was generally best described by a quadratic regression, suggesting a biphasic or hormetic response. A similar pattern was found with the number of fungal species as the dependent variable. Anguillospora filiformis and Anguillospora longissima were generally least inhibited by metal supplements, and Ca2+ was the least and Cd2+ the most toxic metal. Combinations of metals had a more severe effect on fungal sporulation than predicted from addition of the effects of the metals in isolation. The biological significance of the hormetic response is unclear; however, acknowledging it is clearly relevant for establishing guidelines or recommendations in toxicology. Environ. Toxicol. Chem. 2011;30:2868–2873. © 2011 SETAC
Estimation of equivalent circuits for induction motors in steady state including mechanical and stray load losses
Authors: Torrent Marcel
Published: September 2011

This paper presents equivalent circuits for analysing induction motors, including parameters that evaluate the mechanical losses and additional load losses, with the objective of achieving a power balance with all losses included in the equivalent circuit parameters. The different options of the circuits are presented, including two resistors that evaluate the losses with three commonly used models: single‐cage, double‐cage and slip‐dependent rotor parameters. Using nonlinear programming techniques, the equivalent circuit parameters were calculated in the different models from rated motor specifications on three induction motors (0.75, 1.5 and 5.5 kW). These motors were tested according to Standard IEC 60034‐2‐1 to compare the mechanical and additional load losses obtained in the proposed equivalent circuits analysis to those obtained according to standard tests. The equivalent circuit was calculated to the manufacturer's data for a four‐pole, 50‐Hz, class B, standard efficiency motors, with rated output power between 0.75 and 200 kW. Finally, a losses study was performed, and the separation of losses to the rated point was obtained for the studied motors. Copyright © 2011 John Wiley & Sons, Ltd.
Silurian‐Devonian coral associations across a sequence stratigraphic boundary in the Argentine Precordillera
Authors: Carrera Marcelo G. , Montoya Ezequiel , Rustán Juan J. , Halpern Karen
Published: September 2011

Silurian and Devonian corals occur abundantly in siliciclastic rocks of the Argentine Precordillera. They are distributed along a Silurian storm‐dominated shallow‐water platform, a transitional restricted nearshore environment, and a Devonian muddy platform setting. Four main associations of rugose and tabulate corals have been recorded: a Silurian association, a lowermost Devonian and two associations in Lower Devonian rocks. The Silurian shallow‐water platform coral association shows abundant colonies of a tabulate pleurodictyform coral. The type and the domical form of corals indicate high‐energy environments. The lowermost Devonian coral association shows the abundance of the tabulate coral Argentinella argentina, which could have formed patches in protected low‐energy environments. The Lower Devonian coral associations correspond to a muddy platform environment. The first one includes rugose and hemispherical tabulate corals and the second is composed of tabulate corals assigned to Parastriatopora sanjuanina, and Parastriatopora sp. They are long stick‐like, fasciculate forms, grouped in apparently life position. Rugose and tabulate corals in the Upper Silurian and Lower Devonian of Argentina constitute low‐diversity associations of western Gondwana, developed in mid‐ to high‐latitudes. The morphologies acquired by corals are related to water energy. Laminar or encrusting forms were more competitive in the Silurian shallow‐water, high‐energy environments. Slender branching forms with a high profile typically inhabited Devonian relatively deeper water or protected settings. The stratigraphic distribution observed partially followed the well‐ known pattern in which shallow‐water faunas disappeared during regressive events and are replaced by new forms in the subsequent transgressive sequence. The turnover pattern detected across the Silurian‐Devonian transitional interval is in agreement with that previously recognized on the basis of the accompanying fauna. Copyright © 2011 John Wiley & Sons, Ltd.
Catchment‐scale estimates of flow path partitioning and water storage based on transit time and runoff modelling
Authors: Soulsby C. , Piegat K. , Seibert J. , Tetzlaff D.
Published: September 2011

Tracer‐derived mean transit times (MTT) and rainfall–runoff modelling were used to explore stream flow generation in 14 Scottish catchments. Both approaches conceptualise the partitioning, storage, and release of water at the catchment scale. The study catchments were predominantly upland and ranged from 0.5 to 1800 km2. Lumped convolution integral models using tracer input–output relationships generally provided well‐constrained MTT estimates using a gamma function as the transit time distribution. These ranged from 60 days to >10 years and are mainly controlled by catchment soil cover and drainage density. The HBV model was calibrated using upper and lower storage layers to conceptualise rapidly responding near‐surface flow paths and slower groundwater contributions to runoff. Calibrated parameters that regulate groundwater recharge and partitioning between the two storages were reasonably well‐identified and correlations with MTTs. The most clearly identified parameters and those with the strongest correlations with MTT and landscape controls (particularly soil cover) were the recession coefficients which control the release of water from the upper and lower storage layers. There was also strong correlation between the ‘dynamic’ storage estimated by HBV and the ‘total’ catchment storage inferred by tracer damping, although the latter was usually two orders of magnitude greater. This is explained by the different storages estimated: while the ‘total’ storage inferred by tracers also includes the passive storage involved in mixing, the model estimates ‘dynamic’ storage from water balance considerations. The former can be interpreted as relating to total porosity, whereas the latter rather corresponds to the drainable porosity. As MTTs for Scottish the uplands can be estimated from catchment characteristics, landscape analysis can be used to constrain sensitive model parameters when modelling in ungauged basins. Furthermore, the ‘dynamic’ storage inferred by HBV may also be used to provide a first approximation of minimum total catchment storage. Copyright © 2011 John Wiley & Sons, Ltd.
Influence of antecedent soil moisture on hydraulic conductivity in a series of texture‐contrast soils
Authors: Hardie Marcus A. , Doyle Richard B. , Cotching William E. , Mattern Kathrin , Lisson Shaun
Published: September 2011

Antecedent soil moisture significantly influenced the hydraulic conductivity of the A1, A2e and B21 horizons in a series of strong texture‐contrast soils. Tension infiltration at six supply potentials demonstrated that in the A1 horizon, hydraulic conductivity was significantly lower in the ‘wet’ treatment than in the ‘dry’ treatment. However in the A2e horizon, micropore and mesopore hydraulic conductivity was lower in the ‘dry’ treatment than the ‘wet’ treatment, which was attributed to the precipitation of soluble amorphous silica. In the B21 horizon, desiccation of vertic clays resulted in the formation of shrinkage cracks which significantly increased near‐saturated hydraulic conductivity and prevented the development of subsurface lateral flow in the ‘dry’ treatment. In the ‘wet’ treatment, the difference between the hydraulic conductivity of the A1 and B21 horizons was reduced; however, lateral flow still occurred in the A1 horizon due to difficulty displacing existing soil water further down the soil profile. Results demonstrate the need to account for temporal variation in soil porosity and hydraulic conductivity in soil‐water model conceptualisation and parameterisation. Copyright © 2011 John Wiley & Sons, Ltd.
Social Antecedents of Children's Trustworthiness
Authors: Rotenberg Ken J. , Betts Lucy R. , Eisner Manuel , Ribeaud Denis
Published: September 2011

A total of 1329 children were tested twice across 1 year (M = 7 years 5 months of age at Time 1 (T1)) in the Zurich Project on Social Development. The measures at T1 were corporal punishment, neighbourhood trustworthiness and children's trustworthiness (not lying/cheating and not stealing). At Time 2 (T2), children reported the promise keeping of their classmates, which, via social relations analyses, yielded evidence for individual differences in reliability trustworthiness. Structural equation modelling analyses confirmed that there was stability in children's trustworthiness as a latent variable. The structural equation modelling further yielded evidence that (1) corporal punishment at T1 was negatively associated with children's trustworthiness at T1 and negatively predicted changes in children's trustworthiness and (2) neighbourhood trustworthiness at T1 was positively associated with children's trustworthiness at T1 and positively predicted changes in children's trustworthiness. The findings yielded support for the hypotheses that corporal punishment negatively, and neighbourhood trustworthiness positively, contributes to the development of trustworthiness in children. Copyright © 2011 John Wiley & Sons, Ltd.
Anti‐tumor activity of a B‐cell receptor‐targeted peptide in a novel disseminated lymphoma xenograft model
Authors: Wehr Claudia , Müller Fabian , Schüler Julia , Tomann Tina , Nitschke Claudia , Seismann Henning , Spillner Edzard , Klingner Kerstin , Schneider‐Merck Tanja , Binder Mascha , Fiebig Heinz‐Herbert , Mertelsmann Roland , Trepel Martin
Published: September 2011

Receptor‐targeted therapies have become standard in the treatment of various lymphomas. In view of its unparalleled specificity for the malignant B‐cell clone, the B‐cell receptor (BCR) on B cell lymphoma cells is a potential therapeutic target. We have used two BCR epitope mimicking peptides binding to the Burkitt's lymphoma cell lines CA46 and SUP‐B8. We proved their functionality by demonstrating calcium flux and BCR‐mediated endocytosis upon peptide receptor binding. Toxicity experiments in vitro
via cross‐linking of the BCR with tetramerized epitope mimics lead to apoptosis in both cell lines but was far more effective in SUP‐B8 cells. We established a SUP‐B8‐based disseminated Burkitt's lymphoma model in NOD/SCID mice. Treatment of tumor‐bearing mice with tetramerized epitope mimics had significant anti‐tumor effects in vivo. We conclude that peptide‐mediated, BCR‐targeted therapy is a promising approach which may be explored and further developed for application in highly aggressive lymphoma.
ASSESSMENT OF IRRIGATION SYSTEM PERFORMANCE IN SOUTH‐WESTERN BURKINA FASO
Authors: Dembele Youssouf , Yacouba Hamma , Keïta Amadou , Sally Hilmy
Published: September 2011

A methodology for assessing irrigation system performance was developed by the then International Irrigation Management Institute (IIMI, now IWMI) in the 1990s in Burkina Faso. It was applied successfully to small‐scale reservoir‐based irrigation schemes (50–150 ha). The current study was carried out on two larger river‐diversion irrigation systems in the south‐west of the country, namely Vallée du Kou (1200 ha) and Karfiguéla (350 ha), in order to analyse and verify:

the applicability of the methodology to large‐scale river‐diversion schemes with more complex hydraulic networks and greater economic activities;

the relevance of the performance indicators used and the constraints pertaining to the acquisition of the basic data required for their determination;

the scope for adoption and application of the methodology by farmers' organizations for routine performance monitoring.

The methodology seems well suited for large‐scale irrigation systems, but its adoption by farmers' organizations has to be facilitated and accompanied by adequate training and the close involvement of the system managers. The indicators requiring the manipulation of a few physical elements can be determined relatively easily. Those involving water measurements are more difficult to calculate. The study makes a critical analysis of some indicators and demonstrates the evidence of the necessity to select among the indicators with regard to the irrigation system context. Copyright © 2011 John Wiley & Sons, Ltd.
Development of an “early warning” sensor for encrustation of urinary catheters following Proteus infection
Authors: Malic Sladjana , Waters Mark G. J. , Basil Leo , Stickler David J. , Williams David W.
Published: September 2011

Biofilm formation in long‐term urinary catheterized patients can lead to encrustation and blockage of urinary catheters with serious clinical complication. Catheter encrustation stems from infection with urease‐producing bacteria, particularly Proteus mirabilis. Urease generates ammonia from urea, and the elevated pH of the urine results in crystallization of calcium and magnesium phosphates, which block the flow of urine. The aim of this research is to develop an “early warning” silicone sensor for catheter encrustation following bacterial infection of an in vitro bladder model system. The in vitro bladder model was infected with a range of urease positive and negative bacterial strains. Developed sensors enabled catheter blockage to be predicted ∼17–24 h in advance of its occurrence. Signaling only occurred following infection with urease positive bacteria and only when catheter blockage followed. In summary, sensors were developed that could predict urinary catheter blockage in in vitro infection models. Translation of these sensors to a clinical environment will allow the timely and appropriate management of catheter blockage in long‐term catheterized patients. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Biomimetic mineralization of dentin induced by agarose gel loaded with calcium phosphate
Authors: Ning Tian‐Yun , Xu Xiao‐Hui , Zhu Li‐Fang , Zhu Xiao‐Peng , Chu Chun Hung , Liu Lai‐Kui , Li Quan‐Li
Published: September 2011

A novel biomimetic mineralization system was designed to induce a layer of hydroxyapatite on a demineralized dentin surface. This system was constructed as follows. A layer of 0.5% agarose gel containing 0.26M Na2HPO4 was used to cover acid‐etched dentin slices, followed by a layer of agarose gel without phosphate ions. Then a neutral 0.13M CaCl2 solution was added onto the ion‐free gel surface. The mineralization system (dentin‐agarose gel containing phosphate ions‐CaCl2 solution) was kept in a water bath at 37°C, and the gel and CaCl2 solution were replaced at various intervals. The results showed that the deposited hydroxyapatite crystals densely packed to each other, completely covered the dentin surface, and occluded the dentinal tubules after 10 days of biomimetic mineralization in vitro. Therefore, this method may provide the experimental basis for dentin remineralization and for a new method to treat dentin hypersensitivity and dental caries. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Rapidly increasing rates of hip fracture in Beijing, China
Authors: Xia Wei-Bo , He Shu-Li , Xu Ling , Liu Ai-Ming , Jiang Yan , Li Mei , Wang Ou , Xing Xiao-Ping , Sun Yue , Cummings Steven R.
Published: September 2011

The age-specific rates of hip fractures have been declining in most countries in the West but a few studies suggest that the rates might be increasing in areas of Asia that are undergoing urbanization. We previously conducted a population-based study of hip fracture rates in Beijing, China, in 1990 to 1992 that included validation of hip fracture cases. Using a similar approach to validate cases, we estimated the age-specific hip fracture rates in Beijing, China, for 2002 to 2006. Specifically, we obtained hospital discharge data for hip fractures that were reported to the Beijing Bureau of Public Health. To confirm the diagnoses, Beijing residence, and find cases missed by the public records we checked individual cases in the public health records against medical records in a random sample of Beijing hospitals. The rates from public health data were adjusted for these under- and overestimations. We found that between 1990 and 1992 and 2002 and 2006, the adjusted age-specific rates of hip fracture over age 50 years increased 2.76-fold (95% confidence interval [CI], 2.68–2.84) in women and 1.61-fold (95% CI, 1.56–1.66) in men. Over age 70 years, the age-specific rates increased 3.37-fold (95% CI, 3.28–3.47) in women and 2.01-fold (95% CI, 1.95–2.07) in men. From 2002 to 2006, the rates over age 50 years increased 58% in women and 49% in men. We conclude that the rate of hip fracture has been rising very rapidly in Beijing, China. Therefore, the burden of hip fractures may be shifting rapidly from the West to urbanizing areas of the East. © 2012 American Society for Bone and Mineral Research
Critical evaluation of the use of cell cultures for inclusion in clinical trials of patients affected by collagen VI myopathies
Authors: Sabatelli P. , Palma E. , Angelin A. , Squarzoni S. , Urciuolo A. , Pellegrini C. , Tiepolo T. , Bonaldo P. , Gualandi F. , Merlini L. , Bernardi P. , Maraldi N.M.
Published: September 2011

Collagen VI myopathies (Ullrich congenital muscular dystrophy (UCMD), Bethlem myopathy (BM), and myosclerosis myopathy) share a common pathogenesis, that is, mitochondrial dysfunction due to deregulation of the permeability transition pore (PTP). This effect was first identified in the Col6a1−/− mouse model and then in muscle cell cultures from UCMD and BM patients; the normalizing effect of cyclosporin A (CsA) confirmed the pathogenic role of PTP opening. In order to determine whether mitochondrial performance can be used as a criterion for inclusion in clinical trials and as an outcome measure of the patient response to therapy, it is mandatory to establish whether mitochondrial dysfunction is conserved in primary cell cultures from UCMD and BM patients. In this study we report evidence that mitochondrial dysfunction and the consequent increase of apoptotic rate can be detected not only, as previously reported, in muscle, but also in fibroblast cell cultures established from muscle biopsies of collagen VI‐related myopathic patients. However, the mitochondrial phenotype is no longer maintained after nine passages in culture. These data demonstrate that the dire consequences of mitochondrial dysfunction are not limited to myogenic cells, and that this parameter can be used as a suitable diagnostic criterion, provided that the cell culture conditions are carefully established. J. Cell. Physiol. 227: 2927–2935, 2012. © 2011 Wiley Periodicals, Inc.
Effect of vascular endothelial growth factor gene transfer on infarct size, left ventricular function and myocardial perfusion in sheep after 2 months of coronary artery occlusion
Authors: Vera Janavel Gustavo L. , De Lorenzi Andrea , Cortés Claudia , Olea Fernanda D. , Cabeza Meckert Patricia , Bercovich Andrés , Criscuolo Marcelo , Laguens Rubén , Crottogini Alberto
Published: September 2011

Background

In large mammalian models of acute myocardial infarction (AMI), plasmid‐mediated vascular endothelial growth factor (pVEGF) gene transfer has been shown to induce angio‐arteriogenesis, proliferation of myocyte precursors and adult cardiomyocyte mitosis, reducing infarct size at 15 days after coronary artery occlusion. However, it is unknown whether these effects persist at longer follow‐up times, nor how they affect cardiac performance. We thus assessed infarct size, left ventricular (LV) function and perfusion in 2‐month‐old ovine AMI.

Methods

Adult sheep with coronary artery occlusion were randomized to blindly receive ten intramyocardial injections of 3.8 mg of pVEGF or empty plasmid distributed at the infarct border. Three and 60 days later, LV perfusion (single‐photon emission computed tomography) and function (stress echocardiography) were assessed. Finally, hemodynamics (LV catheterization), scar size and peri‐infarct histology were studied.

Results

Infarct size was 30% smaller in pVEGF‐treated sheep (23.6 ± 1.9% versus 32.7 ± 2.7% of the LV; p < 0.02). Percentage fractional shortening and wall thickening at the infarct border improved after pVEGF, as did myocardial perfusion and LV wall motion under pharmacological stress. Global LV function did not differ between groups, although the force‐frequency response was preserved in pVEGF group and lost in placebo animals. These effects were associated with angio‐arteriogenesis and proliferation of cardiomyocyte precursors.

Conclusions

In sheep with AMI, pVEGF gene transfer affords long‐term infarct size reduction, yielding regional LV function and perfusion improvement and reducing remodeling progression. These results suggest the potential usefulness of this approach in the clinical setting. Copyright © 2012 John Wiley & Sons, Ltd.