bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral Iron(II) and Cobalt(II) Complexes with Biphenyl‐Bridged Bis(pyridylimine) Ligands – Syntheses, Structures and Reactivities
Authors: Vedder Christoph , Schaper Frank , Brintzinger Hans‐Herbert , Kettunen Mika , Babik Sebastian , Fink Gerhard 
Published: March 2005

AbstractA new class of iron(II) and cobalt(II) complexes with neutral, tetradentate bis(pyridylimine) chelate ligands bridged by a chiral 6,6′‐dimethylbiphenyl backbone has been synthesized. Their dihalogen derivatives gave spectral, magnetic and X‐ray diffraction results in agreement with a C2‐symmetric, approximately octahedral geometry with cis‐positioned halide ligands and high‐spin d‐electron configuration. 1H NMR signals of these paramagnetic complexes were assigned by correlating line widths with reciprocal proton‐metal distances. Methyl substitution in 6‐position of the pyridyl rings lead to a different, presumably square‐pyramidal coordination geometry under dissociation of one chloride ion. FeII dimethyl and diisocyanide derivatives were shown to have low‐spin configuration and C1‐symmetric geometry. With respect to MAO‐activated olefin polymerization, significant catalytic activities were reproducibly obtained only under conditions, where the original complex structure was degraded. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Alternative Coordination Modes in Palladium(II)‐Diimino‐Bispyridine Complexes with an Axially Chiral Biphenyl Backbone
Authors: Kettunen Mika , Vedder Christoph , Brintzinger Hans‐Herbert , Mutikainen Ilpo , Leskelä Markku , Repo Timo 
Published: March 2005

AbstractThe chiral biphenyl‐bridged diimino‐bispyridine ligandsN,N′‐(6,6′‐dimethylbiphenyl‐2,2′‐diyl)bis(2‐pyridylmethyl)‐diimine(1)and N,N′‐(6,6′‐dimethylbiphenyl‐2,2′‐diyl)bis[(6‐methyl‐2‐pyridyl)methyl]diimine (2) react with Pd(COD)Cl2 to give, depending on the reaction conditions, either mono‐ or binuclear PdCl2 complexes. In the binuclear complex 1‐(PdCl2)2, the Pd nuclei are held at a distance of 3.37 Å by the ligand backbone. N,N′‐(6,6′‐dimethylbiphenyl‐2,2′‐diyl)bis[(5‐methyl‐2‐furyl)methyl]diimine (3), with furyl instead of pyridyl rings, gives mononuclear, C2‐symmetric complexes only. Reactions of [Pd(NCCH3)4]2+ (BF4–)2 with ligand 1 or 3 give the C2‐symmetric cations [1‐Pd]2+or [3‐Pd(NCCH3)2]2+, respectively, as their BF4– salts. Solid‐state structures of the chloride complexes 1‐PdCl2, 1‐(PdCl2)2 and 3‐PdCl2, and of the complex cations [1‐Pd]2+ and [3‐Pd(NCCCH3)2]2+ with tetradentate and bidentate ligand coordination, respectively, all show square‐planar coordination, with some distortion toward tedrahedral geometry due to the twisted biaryl‐backbone. Preliminary observations on norbornene polymerization with the catalysts 1‐PdCl2/MAO, 2‐PdCl2/MAO and [(3‐Pd(NCCH3)2]2+ suggest that a certain degree of stereoregularity of the polymers is induced by these chiral catalysts. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
A novel procedure for the measurement of the kinetics of styrene biodegradation in a biofilter
Authors: Jorio Hasnaa , Brzezinski Ryszard , Heitz Michèle 
Published: March 2005

AbstractA novel procedure for the study of the biodegradation kinetics of styrene is proposed in this paper. Microbial growth tests in the presence of styrene were performed using suspensions of microorganisms prepared from samples of filter bed material. This material had been directly withdrawn previously from an operating biofilter employed for the removal of styrene vapours from air. The kinetics tests were initiated immediately after transfer of filter bed samples from the active styrene filter bed to sealed flasks containing a mineral‐based medium, and were performed in such a manner that no enrichment technique or lag phase treatment was necessary to activate the desired biodegradation of styrene. The complete biodegradation of freshly introduced styrene was observed within a few hours of the filter bed's initial contact with the active microbial suspension. A novel theoretical development, as proposed in this study, has provided us with the means for estimating the yield coefficient of the biomass with respect to the styrene consumed and the kinetic coefficients of the growth rate without having to perform any analyses of the liquid phase after start‐up of the growth tests. Only monitoring of the styrene and carbon dioxide concentrations in the liquid and gas phases in the test flasks was necessary. The Haldane model, with inhibition expected at high styrene concentrations, was found to be the best to represent the biodegradation kinetics of styrene in this environment. Copyright © 2005 Society of Chemical Industry
End binding protein‐1 (EB1) complements microtubule‐associated protein‐1B during axonogenesis
Authors: Jiménez‐Mateos Eva M. , Paglini Gabriela , González‐Billault Christian , Cáceres Alfredo , Avila Jesús 
Published: March 2005

AbstractThe different strains of microtubule‐associated protein (MAP)‐1B‐deficient mice that have been generated appear to express different phenotypes. This variability could be the consequence of the distinct genetic backgrounds of the animals used to generate these lines. Certain proteins might be able to complement the deficit of MAP1B function in these mice. Therefore, we examined whether the concentrations of potential compensatory proteins varied among these mutant strains. In this way, we identified significant differences in the amounts of the microtubule‐associated EB1 protein between two of these strains. Furthermore, in transfection studies, we demonstrated that the overexpression of end binding protein‐1 (EB1) could facilitate axonogenesis in MAP1B–/– cells in which EB1 is normally weakly expressed. Thus, we suggest that EB1 could complement MAP1B function during neural development. © 2005 Wiley‐Liss, Inc.
Frequency‐dependent recruitment of inhibition mediated by stellate cells in the rat cerebellar cortex
Authors: Rancillac A. , Barbara J.G. 
Published: March 2005

AbstractIn the cerebellum, dendritic inhibition of Purkinje cells (PCs) is mediated by stellate cells (SCs). These inhibitory interneurons are critically involved in the cerebellar network; they control the timing and firing frequency of PCs, the only output cells of the cerebellar cortex. However, the underlying properties of parallel fiber (PF) to SC excitatory synapses have not been fully determined. To characterize the conditions favoring the recruitment of SCs in the cerebellum, we analyzed evoked and spontaneous excitatory postsynaptic currents (EPSCs) recorded from SCs of rat cerebellar slices. We found that SC EPSCs evoked with single suprathreshold‐intensity stimulations were mostly unitary, with a large amplitude and variable latencies, and failed with a high rate. Increasing the frequency of stimulation above 60 Hz significantly reduced failures, whereas mean SC EPSC amplitude was increased by less than 20%. Decreasing failures at PF‐SC synapses experimentally enhanced the number of asynchronous SC EPSCs per stimulation but, again, moderately increased the mean SC EPSC amplitude. Finally, brief presynaptic bursts transiently depressed synaptic transmission. This depression resulted from the release of endocannabinoids and might act as a negative‐feedback mechanism. Thus, we conclude that SC EPSCs evoked with single suprathreshold‐intensity stimulations are mostly unitary and that PF‐SC synapse efficacy is highly regulated by the presynaptic temporal pattern of activity and the frequency of afferent inputs. Such synaptic properties may control the responsiveness of SC synapses to the frequency of PF stimulations, which may control the spatial extent and duration of the recruitment of inhibition in the cerebellar cortex. © 2005 Wiley‐Liss, Inc.
On the median residual lifetime and its aging properties: A characterization theorem and applications
Authors: Lillo Rosa E. 
Published: March 2005

AbstractThis paper is devoted to study several aspects of the median residual life function (MERLF). In reliability studies, it is well known that, although the MERLF have several advantages over the mean residual life function (MRLF), the MRLF has the good property of uniquely determine a life distribution whereas either the median residual life function (MERLF) or an α‐percentile residual life do not have such good property. We shall give a characterization result where knowledge of both the MERLF and the survival function on an interval does uniquely determine the distribution. Moreover, in order to apply this characterization in practical situations, we propose a method to estimate the necessary information of the survival function. Relationships between analytical properties of the survival function and its associated MERLF are also obtained. Bryson and Siddiqui [J Am Statist Assoc 64 (1969), 1472–1483] proved relationships among seven criteria for aging, out of which two contained the MRLF (decreasing MRLF and net decreasing MRLF). In this paper, we prove that the same pattern of relationships holds if the MRLF is replaced by the MERLF. We also examine the aging criteria corresponding to an increasing MERLF and show that there is no relation between the behavior (increasing or decreasing) of the MERLF and of the MRLF. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005
Force identification of dynamic systems using genetic programming
Authors: Yang Y. W. , Wang C. , Soh C. K. 
Published: March 2005

AbstractOne obvious limitation of the traditional force identification techniques is that they are unable to obtain the explicit expression of the force. Moreover, some techniques need both the displacement and velocity data of all freedoms, and some need the Markov parameters from numerical calculation or experimental test before the force identification can be carried out. This paper presents a genetic programming (GP) based method for excitation force identification of dynamic systems to overcome these traditional methods' disadvantages. GP is employed as a search and optimization method to obtain the optimal, if not the best, force expression from the known dynamic response. One obvious merit of the proposed method is that it can obtain the explicit expression of the unknown force. Another advantage is that it only needs the dynamic response data at one point, i.e. displacement or velocity or acceleration of one freedom. Illustrative examples demonstrate that the GP based method is able to identify the excitation force of a single‐degree, a three‐degree dynamic systems and a frame structure, depicting its potential for force forecast problems. Copyright © 2005 John Wiley & Sons, Ltd.
Pathophysiologic mechanisms of persistent pulmonary hypertension of the newborn
Authors: Dakshinamurti S. 
Published: March 2005

AbstractPersistent pulmonary hypertension of the newborn (PPHN), among the most rapidly progressive and potentially fatal of vasculopathies, is a disorder of vascular transition from fetal to neonatal circulation, manifesting as hypoxemic respiratory failure. PPHN represents a common pathway of vascular injury activated by numerous perinatal stresses: hypoxia, hypoglycemia, cold stress, sepsis, and direct lung injury. As with other multifactorial diseases, a single inciting event may be augmented by multiple concurrent/subsequent phenomena that result in differing courses of disease progression. I review the various mechanisms of vascular injury involved in neonatal pulmonary hypertension: endothelial dysfunction, inflammation, hypoxia, and mechanical strain, in the context of downstream effects on pulmonary vascular endothelial‐myocyte interactions and myocyte phenotypic plasticity. © 2005 Wiley‐Liss, Inc.
Oral treatment of the TRAMP mice with doxazosin suppresses prostate tumor growth and metastasis
Authors: Chiang Cheng‐Feng , Son Eugene Lee , Wu Guang‐Jer 
Published: March 2005

AbstractBACKGROUNDWe used the TRAMP mouse model for testing the effect of oral doxazosin treatment on the in vivo prostate tumor growth and metastasis.METHODSFive groups of TRAMP mice at different ages were orally fed with 1 mg/kg of doxazosin or DMSO for 45–196 days. At the end of oral treatment, tumor weight was determined, and metastasis to multiple organs examined. The levels of MUC18, Bcl‐2, Bax, caspase‐3, poly (ADP‐ribose) polymerase (PARP), phospho (Ser473)‐AKT, and Ki‐67 in the mouse prostate tumors were determined.RESULTSOral treatment of the TRAMP mice with doxazosin for 45–81 days did not decrease the size of preexisting prostate tumors, but it limited the metastasis to peri‐aortic lymph nodes. A prolonged treatment of TRAMP mice with doxazosin (156–196 days), if administered early, decreased the prostate tumor weight and completely suppressed metastasis. The doxazosin treatment did not further decrease the expression of an already low level of Bcl‐2 in all prostate tumors, but it increased the expression of Bax, and the activation of caspase‐3, and the cleavage of a downstream substrate, PARP. The treatment reduced the expression of MUC18, phospho (Ser473)‐AKT, and Ki‐67. The treatment in the early phase appeared to promote prostate tumor growth and increased the expression of a proliferative index, Ki‐67.CONCLUSIONSDoxazosin, if administered early, may be useful for preventing the prostate tumor formation, and also for limiting or completely suppressing the metastasis of prostate cancer in the TRAMP model. The mechanism of doxazosin is consistent with the established hypothesis. © 2005 Wiley‐Liss, Inc.
Thermodynamic and kinetic characterization of a β‐hairpin peptide in solution: An extended phase space sampling by molecular dynamics simulations in explicit water
Authors: Daidone Isabella , Amadei Andrea , Di Nola Alfredo 
Published: March 2005

AbstractThe folding of the amyloidogenic H1 peptide MKHMAGAAAAGAVV taken from the syrian hamster prion protein is explored in explicit aqueous solution at 300 K using long time scale all‐atom molecular dynamics simulations for a total simulation time of 1.1 μs. The system, initially modeled as an α‐helix, preferentially adopts a β‐hairpin structure and several unfolding/refolding events are observed, yielding a very short average β‐hairpin folding time of ∼200 ns. The long time scale accessed by our simulations and the reversibility of the folding allow to properly explore the configurational space of the peptide in solution. The free energy profile, as a function of the principal components (essential eigenvectors) of motion, describing the main conformational transitions, shows the characteristic features of a funneled landscape, with a downhill surface toward the β‐hairpin folded basin. However, the analysis of the peptide thermodynamic stability, reveals that the β‐hairpin in solution is rather unstable. These results are in good agreement with several experimental evidences, according to which the isolated H1 peptide adopts very rapidly in water β‐sheet structure, leading to amyloid fibril precipitates [Nguyen et al., Biochemistry 1995;34:4186–4192; Inouye et al., J Struct Biol 1998;122:247–255]. Moreover, in this article we also characterize the diffusion behavior in conformational space, investigating its relations with folding/unfolding conditions. Proteins 2005. © 2005 Wiley‐Liss, Inc.
PPRODO: Prediction of protein domain boundaries using neural networks
Authors: Sim Jaehyun , Kim Seung‐Yeon , Lee Jooyoung 
Published: March 2005

AbstractSuccessful prediction of protein domain boundaries provides valuable information not only for the computational structure prediction of multidomain proteins but also for the experimental structure determination. Since protein sequences of multiple domains may contain much information regarding evolutionary processes such as gene–exon shuffling, this information can be detected by analyzing the position‐specific scoring matrix (PSSM) generated by PSI‐BLAST. We have presented a method, PPRODO (Prediction of PROtein DOmain boundaries) that predicts domain boundaries of proteins from sequence information by a neural network. The network is trained and tested using the values obtained from the PSSM generated by PSI‐BLAST. A 10‐fold cross‐validation technique is performed to obtain the parameters of neural networks using a nonredundant set of 522 proteins containing 2 contiguous domains. PPRODO provides good and consistent results for the prediction of domain boundaries, with accuracy of about 66% using the ±20 residue criterion. The PPRODO source code, as well as all data sets used in this work, are available from http://gene.kias.re.kr/∼jlee/pprodo/. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Quantum study of mutational effect in binding of efavirenz to HIV‐1 RT
Authors: Mei Ye , He Xiao , Xiang Yun , Zhang Da W. , Zhang J.Z.H. 
Published: March 2005

AbstractFull quantum mechanical computational study has been carried out to study binding of efavirenz (EFZ), a second generation FDA approved nonnucleoside inhibitor, to HIV‐1 reverse transcriptase (RT) and its K103N and Y181C mutants using the MFCC (molecular fractionation with conjugate caps) method. The binding interaction energies between EFZ and each protein fragment are calculated using a combination of HF/3‐21G, B3LYP/6‐31G* and MP2/6‐31G* ab initio levels. The present computation shows that Efavirenz binds to HIV‐1 RT predominantly through strong electrostatic interaction with the Lys101 residue. The small loss of binding to K103N mutant by Efavirenz can be attributed to a slightly weakened attractive interaction between the drug and Lys101 due to a conformational change of mutation. The small loss of binding to Y181C mutant by efavirenz can be attributed to the Glu698 residue moving closer to EFZ due to conformational change, which results in an increase of repulsive energy relative to the wild type (WT). The binding of efavirenz‐derived DPC961 to HIV‐1 RT is enhanced by an additional attractive interaction to residue Hid235 and reduced repulsion to Glu698, resulting in an increase of binding energy by about 4 kcal/mol. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Quantification of banding on printed corrugated board using spatial frequency analysis
Authors: Hallberg Erik , Glasenapp Astrid Odeberg , Lestelius Magnus 
Published: March 2005

AbstractThe human visual system has an exceptional ability to detect systematic print mottle. One type of systematic print mottle is banding on printed corrugated board, resulting in a disturbing print defect. A new method that quantifies banding on printed corrugated board is proposed. The method is based on spatial frequency analysis, and the degree of banding is determined using a band‐pass filter range adapted to fit the flute wavelength and orientation of the acquired image of the printed board. The results for B‐flute corrugated board gave a correlation coefficient of 0.98 between the technical measurements and the subjective ratings. Methods of quantifying the banding on the different types of corrugated board available on the market are discussed. Copyright © 2005 John Wiley &amp; Sons, Ltd.
Polymorphism of Anhydrous Cadmium Iodate Structure of ε‐Cd(IO3)2
Authors: Bentria Bachir , Benbertal Djamal , Hebboul Zoulikha , Bagieu‐Beucher Muriel , Mosset Alain 
Published: March 2005

AbstractThe investigation of CdCl2‐HIO3 system, in aqueous and HNO3 solutions, revealed that anhydrous cadmium iodate presents a marked polymorphism. No less than four new Cd(IO3)2polymorphs have been isolated and characterized, two of which showing second harmonic generation activity. Single crystals of ε‐Cd(IO3)2 are obtained by slowly evaporating, at 60 °C, a saturated solution of γ‐Cd(IO3)2 in 30 % nitric acid. This compound crystallizes in the orthorhombic space group Pca21 [a = 17.581(2), b = 5.495(2), c = 11.163(2) Å]. The basic structural unit can be described as the connection of two cadmium polyhedrons with a short metal – metal distance of 3.88Å. These units are further linked through two other iodate bridges resulting in layers parallel to the (100) plane. The 3D linkage is ensured by short bonds of the fourth iodate group.
Syntheses and Crystal Structures of Cadmium Complexes with Thiophenedicarboxylate and Bipyridine‐like Ligands
Authors: Sun Xian‐Zhong , Huang Zhen‐Li , Wang He‐Zhou , Ye Bao‐Hui , Chen Xiao‐Ming 
Published: March 2005

AbstractTwo new coordination polymers [Cd(tdc)(bpy)(H2O)]n (1) and [Cd(tdc)(phen)]n (2) (H2tdc = thiophene‐2,5‐dicarboxylic acid, bpy = 2,2′‐bipyridine and phen = 1,10‐phenanthroline) have been synthesized under hydrothermal condition. Their crystal structures have been established by X‐ray single‐crystal diffraction. Complex 1 crystallizes in the orthorhombic space group Fdd2 with a = 14.757(7), b = 45.38(2), c = 10.518(5) Å, V = 7044(6) Å3, Z = 16; 2 in the monoclinic space group P21/c with a = 7.262(1), b = 21.970(2), c = 10.051(1) Å, β = 105.01(1)°, V = 1548.8(2) Å3, Z = 4. Both of them are double‐stranded chains and further assembled into three‐dimensional networks by π‐π stacking interactions. 1 and 2 are stable in air, and show blue photoluminescence at 415 nm and 410 nm, respectively.
Crystal Structure and Thermal Behaviour of the Mixed‐Valent Basic Mercury Nitrate HgI2(OH)(NO3)·HgIIO
Authors: Weil Matthias 
Published: March 2005

AbstractSingle crystals of the hitherto unknown compound Hg2(OH)(NO3)·HgO were obtained unintentionally during hydrothermal phase formation experiments in the system Ag—Hg— As—O. Hg2(OH)(NO3)·HgO (orthorhombic, Pbca, Z = 8, a = 6.4352(8), b = 11.3609(14), c = 15.958(2) Å, 1693 structure factors, 83 parameters, R1[F2 > 2σ(F2)] = 0.0431) adopts a new structure type and is composed of two types of mercury‐oxygen zig‐zag‐chains running perpendicular to each other and of intermediate nitrate groups. One type of chains runs parallel [010] and consists of (Hg—Hg—OH) units with a typical Hg—Hg distance of 2.5143(10) Å for the mercury dumbbell, whereas the other type of chains runs parallel [100] and is made up of (O—Hg—O) units with short Hg—O distances of about 2.02Å. Both types of chains are concatenated by a common O atom with a slightly longer Hg—O distance of 2.25Å. The three‐dimensional assembly is completed by nitrate groups whose O atoms show Hg—O distances > 2.80Å. Weak hydrogen bonding between the OH group and one oxygen atom belonging to the nitrate group stabilizes this arrangement. Hg2(OH)(NO3)·HgO decomposes above 200 °C to HgO.
Magnetic, Spectroscopic and Thermal Study of [Cu(NO3)(PyTz)2](NO3). A Copper(II) Complex Containing Thiazine Derivative Ligand
Authors: Barros‐García F. J. , Bernalte‐García Avaro , Lozano‐Vila A. M. , Luna‐Giles F. 
Published: March 2005

AbstractThe copper(II) complex [Cu(NO3)(PyTz)2](NO3) has been previously characterized means X‐ray powder diffraction and now studied by IR spectroscopy, UV‐Vis‐NIR diffuse reflectance, magnetic susceptibility measurement, electronic spin resonance (ESR) and thermal analysis. The results are correlated with a distorted square pyramidal coordination around copper(II) ion rather than the cis‐distorted octahedral stereochemistry of a CuN4OO′ chromophore in good concordance with their structure. Likewise, in order to indicate towards what square pyramidal isomer the complex is distorted, the method proposed by Carugo and Bisi has been applied to the structural data of [Cu(NO3)(PyTz)2](NO3). It is deduced that there is a large distortion from the trigonal bipyramid geometry, close to a square pyramid geometry, being produced almost exclusively through the B route of the Berry mechanism.