bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chiral Arene Ruthenium Complexes: Synthesis and Molecular Structure of the Enantiopure Cluster Cation (S)‐[H3Ru3{C6H5[CH(CH3)CH2OH]}(C6Me6)2(O)]+
Authors: Vieille‐Petit Ludovic , Therrien Bruno , Süss‐Fink Georg 
Published: October 2003

AbstractThe reaction of enantiopure (R)‐(2‐cyclohexa‐1,4‐dienyl)propan‐1‐ol with ruthenium chloride hydrate yields, without racemisation of the chiral ligand, the chloro‐bridged dinuclear complex (S,S)‐[RuCl2{C6H5[CH(CH3)CH2OH]}]2 (1). The dimer 1 reacts with triphenylphosphane to give the mononuclear complex (S)‐[RuCl2{C6H5[CH(CH3)CH2OH]}(PPh3)] (2). A single‐crystal X‐ray structure analysis of 2 reveals the absolute configuration of the asymmetric carbon atom to have remained, the change from (R) to (S) being due to the priority change caused by coordination; in the solid state, onedimensional hydrogen‐bonded chains are formed between the hydroxy functions and chloro ligands of neighbouring molecules. The mononuclear cationic complex (S)‐[Ru{C6H5[CH(CH3)CH2OH]}(H2O)3]2+, formed in situ from 1 in aqueous solution, reacts with the dinuclear complex [H3Ru2(C6Me6)2]+ to give a chiral trinuclear arene‐ruthenium cluster, the cation (S)‐[H3Ru3{C6H5[CH(CH3)CH2OH]} (C6Me6)2(O)]+ (3). This enantiopure cation has been isolated and characterised as its tetrafluoroborate salt. The single‐crystal X‐ray structure analysis of (S)‐[3][BF4] shows a strong intramolecular hydrogen bond between the μ3‐oxo cap and the hydroxy function, which also persists in acetone solvent, as demonstrated by NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
New Tris(pyrazolyl)triazine and Pyrazolylpyridine Gold(I) and Palladium(II) Derivatives Based on the 3,5‐Bis(4‐butoxyphenyl)pyrazole Group − Architectures with Different Types of Bonding Interactions
Authors: Claramunt Rosa M. , Cornago Pilar , Cano Mercedes , Heras José V. , Gallego M. Luz , Pinilla Elena , Torres M. Rosario 
Published: October 2003

AbstractThe 3,5‐bis(4‐butoxyphenyl)pyrazolyl group (Pzbp2) has been used as a building block for mono‐ and polymetallic derivatives of 2,4,6‐tris[3,5‐bis(4‐butoxyphenyl)pyrazol‐1‐yl]‐1,3,5‐triazine (TPzbp2Tz, 1), 2‐[3,5‐bis(4‐butoxyphenyl)pyrazol‐1‐yl]pyridine (Pzbp2Py, 2), and 3,5‐bis(4‐butoxyphenyl)pyrazole (HPzbp2, 3) ligands. The synthesis and characterisation of the new hexadentate ligand 1 are described, together with the chemistry of its metal complexes containing [Pd(η3‐C3H5)]+ and [Au(PPh3)]+ fragments. The related complexes containing Pzbp2Py (2) were also studied and their structural characteristics were compared to those of the TPzbp2Tz species. The role of the counter‐ion on the supramolecular assembly of complexes containing the HPzbp2 ligand 3 was made clear by the X‐ray structures of [Pd(η3‐C3H5)(HPzbp2)2](BF4) and [Au(HPzbp2)(PPh3)](NO3). Hydrogen bonds and/or bonding interactions are responsible for pseudohelical one‐dimensional polymers or supramolecular columnar arrays, respectively. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Empowerment psychotherapy with adolescent females of color
Authors: Querimit Dara S. , Conner Latoya C. 
Published: October 2003

AbstractWe present an empowerment model that fosters strengths and promotes positive identity development among adolescent females of color. Race, ethnicity, gender, and socioeconomic status are integrated in an African American context. A case study illustrates a strength‐based approach to conceptualizing and treating a young, Black adolescent female in her cultural context. We conclude with clinical implications for using an empowerment‐based approach in psychotherapy with culturally diverse adolescent females. © 2003 Wiley Periodicals, Inc. J Clin Psychol/In Session.
Age‐related differences in MAP kinase activity in VSMC in response to glucose or TNF‐α
Authors: Li Muyao , Mossman Brooke T. , Kolpa Emily , Timblin Cynthia R. , Shukla Arti , Taatjes Douglas J. , Fukagawa Naomi K. 
Published: October 2003

AbstractAortic vascular smooth muscle cells (VSMC) were used to study the effect of age on responses to high glucose concentrations or the cytokine, tumor necrosis factor‐alpha (TNF‐α). Activator protein‐1 (AP‐1) binding to DNA increased more in VSMC from old versus young rats (P < 0.02) and was related to increased expression of its components, c‐Fos, Fra‐1, and JunD. The relationship to upstream signals, i.e., activities of mitogen‐activated protein kinases (MAPK), was studied using antibodies to total and phosphorylated forms of extracellular signal‐regulated kinases (ERK), c‐Jun N‐terminal kinases (JNK) and p38. High glucose and TNF‐α increased ERK phosphorylation more in old (P < 0.05); whereas only TNF‐α induced JNK activation in young (P < 0.04). PD98059, a MEK inhibitor, attenuated AP‐1 activation, lowered c‐Fos and Fra‐1 protein levels and reduced cell number and cells positive for proliferating cell nuclear antigen in old. We concluded that age differentially influenced activation of signaling pathways in VSMC exposed to high glucose or TNF‐α. This may contribute to the increased risk for vascular disease associated with aging and diabetes mellitus (DM). J. Cell. Physiol. 197: 418–425, 2003© 2003 Wiley‐Liss, Inc.
Irrigation with plant extracts in ecofarming increases biomass production and mineral and organic nitrogen content of plants
Authors: Gramss Gerhard , Voigt Klaus‐Dieter , Bergmann Hans 
Published: October 2003

AbstractSeedlings of alfalfa, rape, spinach, and wheat, potted on sandy soil, were irrigated with an aqueous extract of pea shoot (PE, 9.84 g dry weight l–1) or a solution of Ca, K, Mg, P, and NO3‐N salts (SS) in a concentration similar to that in PE, for 31–48 days. In comparison to water‐irrigated controls, both SS and PE treated plants showed nearly equal increases in shoot dry weight (29–40 %), whereas PE‐treated plants had higher fresh weights (38–84 %) due to increased succulence. Treatment with SS did not enhance, but sometimes even reduce, the concentrations of Ca, K, Mg, and several trace elements in shoot tissues. In contrast, PE‐treated plants had higher Ca, K, Mg, and organic N, but lower As and Ni contents and were thus of higher nutritive value. Reduced contents of metals in plant tissue correlated with their reduced solubility in the soil solution, which was not due to changes in pH. Fertilizer components such as K and Mg (metals of lower exchange intensity) were incorporated into the soil to release Ca, Sr, and Ba (metals of higher exchange intensity) and reduce the solubility of most trace elements and metal‐complexing humic substances. In addition, application of Ca precipitated heavy metals and humic complexes directly from the soil solution. This effect was partially overcome by PE. Its carboxylic acids could act as phytochelators of metal ions and as mobilizers of the highly diffusible humic substances which carry metals to roots. It is concluded that continuous PE application replaces the quantities of Ca, K, Mg, P, and organic N, but not of NO3‐N consumed during plant growth. Using PE does not add any relevant quantities of toxic metals to the plant‐soil system.
Effect of crop type and crop growth on atmospheric nitrogen deposition
Authors: Böhme Frank , Merbach Ines , Weigel Annett , Russow Rolf 
Published: October 2003

AbstractVarying atmospheric nitrogen (N) depositions for different crops were observed at Bad Lauchstädt (Saxony‐Anhalt, Germany) when using the ITNI system (ITNI = Integrated Total Nitrogen Input), which is based on the 15N isotope dilution method. These differences were only partly explained by climatic influences. The effects of crops on the atmospheric N deposition measured by the ITNI system are discussed. For this purpose, data of six different plant species recorded in 1998 were re‐analyzed. It was found that the airborne N input is closely correlated with the morphology and metabolism of crops. Daily atmospheric N depositions of 129.0–360.8 g per hectare were measured for the plant species used. The nutritional supply of plants, especially with N, is another factor of influence on the N input from the atmosphere which should be considered. To investigate this aspect, a pot experiment was conducted with the grass Lolium perenne at three different N levels. An increase in the airborne N uptake (corresponding to N fertilization) was observed as biomass production rose.
Repräsentanz und Vergleichbarkeit von Daten und Flächen der Bodendauerbeobachtung
Authors: Schröder Winfried , Schmidt Gunther , Pesch Roland 
Published: October 2003

AbstractEs wird ein Verfahren für die Prüfung der Eignung der Daten von Bodendauerbeobachtungsflächen (BDF) der Länder für Bodenschutzaufgaben sowie die Umweltbeobachtung und ‐berichterstattung des Bundes vorgestellt. Grundlage für die Eignungsprüfung der BDF‐Daten sind die Kriterien Landschaftsrepräsentanz sowie Vergleichbarkeit und räumliche Verallgemeinerbarkeit der Messdaten. Die Erfüllung dieser Eignungskriterien wird in einem dreistufigen Ansatz geprüft:1. Erhebung von Informationen über die Vergleichbarkeit der Daten von BDF anhand der Messmethoden und ‐größen einschließlich ihrer Qualitätssicherung;2. statistische Analyse der Repräsentanz von BDF der Länder in Bezug auf flächendeckend verfügbare Daten über bodenschutzrelevante Landschaftsmerkmale sowie3. geostatistische Analyse der räumlichen Verallgemeinerbarkeit der BDF‐Messdaten.Dafür verwendete Daten und Statistik‐Software werden in einem Geographischen Informationssystem (GIS) verknüpft. Die Metadatenanalyse belegt, dass die Bodendauerbeobachtung ökosystemar angelegt ist, einen beachtlichen Grad methodischer Harmonisierung aufweist und deshalb eine besonders wichtige Form des Länder übergreifenden Umweltmonitorings darstellt. Die Repräsentanzanalyse zeigt, dass zur Beurteilung der Effizienz und Suffizienz eines Umweltmessnetzes nicht nur die Landschaftsrepräsentanz seiner Standorte, sondern zusätzlich die geostatistische Repräsentanz der dort erhobenen Daten analysiert werden muss. Hierbei liefert die geostatistische Auswertung Hinweise auf die erforderliche Anzahl der Messstellen, deren räumliche Anordnung an der Landschaftsstruktur orientiert werden sollte.
Effect of sodium chloride on denitrification in glucose amended soil treated with ammonium and nitrate nitrogen
Authors: Azam F. , Müller C. 
Published: October 2003

AbstractLaboratory incubations were conducted to study the effect of sodium chloride (NaCl) on denitrification and respiratory gases (CO2, O2) from soil treated with ammonium or nitrate and incubated at 20 % moisture. The same samples were assayed for denitrifying enzyme activity (DEA) after incubation at 40 % moisture with glucose and NO3–. Under aerobic conditions (20 % water content), a flush of activity was observed at 6 hours after start of incubation and subsided to negligible levels at 12 hours. Sodium chloride significantly depressed N2O and CO2 emissions and O2 consumption. Significantly more loss of N2O occurred from NH4+‐ than NO3–‐treated soil at all NaCl levels and was attributed to higher microbial activity. A highly significant positive correlation was obtained between N2O emission and respiratory gases. The respiratory quotient (CO2 evolved/O2) was higher for NH4+‐treated soil and decreased with the amount of NaCl. At 40 % moisture, N2O emissions were higher than at 20 % and peaked at 37 hours followed by a sharp decrease. Short‐term incubations of soil with NH4+ or NO3– did not have an effect on denitrifying enzyme activity (DEA) while NaCl had a positive effect, particularly in previously NO3–‐treated soil.
Solvent effects on sunscreen active ingredients using Raman spectroscopy
Authors: Beyere L. , Yarasi S. , Loppnow G. R. 
Published: October 2003

AbstractWe present Raman spectra of five sunscreen active ingredients in 10 solvents. Shifts in the UV absorption maxima and the CO Raman mode wavenumber are observed for some of the sunscreens as a function of solvent. Correlations between the observed wavenumber shifts and solvent properties indicate that hydrogen bonding is a key interaction between sunscreen active ingredients and solvent. Interestingly, the relative Raman intensities are also sensitive to the hydrogen‐bonding and polarizability properties of the solvent, reflecting differential stabilization of the sunscreen's resonance structures. These results suggest an ‘expanded polarizability’ view of the solvent's effect on the solute. The observed wavenumber and relative intensity changes were also utilized to identify the active agents present in commercial sunscreen preparations from their in situ Raman spectra. Copyright © 2003 John Wiley & Sons, Ltd.
Application of FT‐Raman and FTIR measurements using a novel spectral reconstruction algorithm
Authors: Sin Su Ying , Widjaja Effendi , Yu Liya E. , Garland Marc 
Published: October 2003

AbstractRecently, an advanced spectral reconstruction algorithm based on information entropy was developed to identify individual compounds contained in mixture spectra without recourse to any library or any a priori knowledge. In this study, standard mixtures containing various polycyclic aromatic hydrocarbons (PAHs) and α,ω‐dicarboxylic acids were measured by solid‐state FT‐Raman and FTIR spectroscopy, and this was followed by the application of the aforementioned algorithm to recover all pure component spectra contained therein. The results demonstrate that the developed algorithm successfully recovered the spectra of individual species even though only a very limited number of mixture spectral measurements were made. FT‐Raman measurements coupled with chemometric analysis provides satisfactory pure spectral results for both PAHs and α,ω‐dicarboxylic acids. Additionally, FT‐Raman measurements together with FTIR measurements provided even better spectral recovery for some of the α,ω‐dicarboxylic acids when using band‐target entropy minimization (BTEM). This study demonstrates that chemometric analysis without a priori information provides a promising solution and simplified approach to identify individual components from samples containing a complex composition. In particular, this is desired for a better understanding of environmental samples. Copyright © 2003 John Wiley & Sons, Ltd.
Use of Hydroxyl Functionalized (Meth)acrylic Cross‐Linked Polymer Microparticles as Chain Transfer Agent in Cationic Photopolymerization of Cycloaliphatic Epoxy Monomer, 1
Authors: Valette Ludovic , Pascault Jean‐Pierre , Magny Benoît 
Published: October 2003

AbstractIn the case of cationic‐type photopolymerized epoxy networks, a new type of chain transfer agent based on hydroxyl functional acrylic cross‐linked polymer microparticles (CPM, also called microgels) has been tested. The CPM functionality was obtained through hydroxyethyl acrylate (HEA) monomer, used as comonomer with butyl acrylate (BA) and hexane diol diacrylate (HDDA). Stabilizing monomers were also required for the synthesis of CPM. In order to compare their particular effects, 4 sets of CPM were synthesized with 4 different stabilizing agents, either hydroxyl functional or not. Consequently, two types of OH groups were present in the particles: primary groups coming from HEA and preferentially located in the particles, and optional hydroxyl groups due to the hydroxyl functional stabilizing agents which were mainly placed onto the particles' surface. The viscoelastic properties of the photopolymerized films have been used to obtain information about the chain transfer reaction and the network microstructure. In all cases, the rubber modulus, $E'_{\rm r}$ was improved because of the decrease of the number of dangling epoxy chains in the epoxy network. When hydroxyl groups were only present in the particles, the mobility of the linkages was assumed to be low, and the mechanical relaxation temperature, Tα, strongly increased. However, CPM aggregation occurred at high CPM concentrations, lowering $E'_{\rm r}$ and Tα. On the contrary, when OH groups were located both on the surface as well as inside the particles, no large CPM aggregation took place, even with [CPM] = 40 wt.‐%. Nevertheless, the presumably higher mobility of the linkages on the particles' surface prevented any Tα increase. The water absorption of all systems based on CPM was very low, around 2% whatever the concentration of chain transfer agent.Schematic description of the transfer reaction between a propagating cationic‐type epoxy chain and a hydroxyl functional CPM.magnified imageSchematic description of the transfer reaction between a propagating cationic‐type epoxy chain and a hydroxyl functional CPM.
The Effect of Transreactions on the Structure and Dynamic Mechanical Properties of 1:1 Poly(ethylene terephthalate)/Poly(ethylene 2,6‐naphthalate) Blends Produced by Cryogenic Mechanical Alloying
Authors: Mano João F. , Denchev Zlatan , Nogales Aurora , Bruix Marta , Ezquerra Tiberio A. 
Published: October 2003

AbstractCryogenically alloyed poly(ethylene terephthalate) (PET)/poly(ethylene naphthalene 2,6‐dicarboxylate) (PEN) blends (1:1 w/w) were subjected to melt pressing at 300 °C for various times. The binary polymer systems so obtained were studied by means of atomic force microscopy (AFM), dynamic mechanical analysis (DMA) and proton NMR. A high level of homogenization at the nanometer scale was achieved. By changing the time of melt pressing in the range of 1–35 min, PET‐PEN block copolymers with average block lengths decreasing between 10 and 2 repeat units were produced. This copolymer formation was accompanied by significant changes in the dynamic mechanical properties as revealed by the variations in the temperature dependence of the loss factor, tan δ, in the region of the glass transition. Particularly, with the increase of annealing time a transition from double to single alpha‐relaxation was observed. The traditional two‐phase Takayanagi model applied to these alpha‐relaxation data did not provide an adequate description of the viscoelastic behavior as a function of annealing time. The results were discussed in terms of the Adam‐Gibbs theory of the cooperatively rearranging regions.
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A refrigeration facility for milk cooling powered by photovoltaic solar energy
Authors: De Blas M. , Appelbaum J. , Torres J. L. , García A. , Prieto E. , Illanes R. 
Published: October 2003

AbstractThe use of renewable energy sources is usually a reliable alternative in rural areas and developing countries, where the grid line does not exist or is at a great distance. In this work, the characteristics and working conditions of a refrigeration facility designed for cooling down an expected daily production of 150 l of milk are analyzed. The facility is a stand‐alone, direct‐coupled system where 20 photovoltaic modules, 120 Wp each, power two permanent magnet, direct current motors of 24 V, 650 W. Each motor drives a separate cooling system compressor, which provides the flexibility to operate the equipment with one or two motors and with various interconnections of the PV modules, depending on the available irradiance level and the thermodynamic state of the system. The photovoltaic energy obtained during daylight hours is stored in the form of sensible and latent heat of frozen water in a tank surrounding a milk container.Thermodynamic analysis of the system shows that the autonomy of the system is 2·5 consecutive cloudy days if the available stored ice energy is 80% of the nominal capacity of the water/ice tank. Results of the refrigeration efficiency are similar to those obtained by other commercial refrigeration facilities powered by a photovoltaic array, including batteries. Copyright © 2003 John Wiley & Sons, Ltd.
Functionalization of polyethylene based on metallocene catalysis and its application to syntheses of new graft copolymers possessing polar polymer segments
Authors: Kashiwa Norio , Matsugi Tomoaki , Kojoh Shin‐Ichi , Kaneko Hideyuki , Kawahara Nobuo , Matsuo Shingo , Nobori Tadahito , Imuta Jun‐Ichi 
Published: October 2003

AbstractThe control of hydroxylated polyethylene (PE) structures was investigated in the copolymerization of ethylene with allyl alcohol or 10‐undecen‐1‐ol with a specific metallocene, methylaluminoxane, and trialkyl aluminum catalyst system through changes in the copolymerization conditions. The incorporation of allyl alcohol into the PE backbones was controllable through changes in the trialkyl aluminum, leading to terminally hydroxylated PE or a copolymer possessing hydroxyalkyl side chains. The copolymerization of ethylene with 10‐undecen‐1‐ol gave copolymers with hydroxyalkyl side chains of various contents with a variety of molecular weights through changes in the copolymerization conditions. The obtained copolymers were useful as macroinitiators that allowed polar polymer segments to grow on the PE backbones, leading to the creation of graft copolymers that possessed PE and polar polymer segments. In this way, polyethylene‐g‐poly(propylene glycol) (PE‐g‐PPG) and polyethylene‐g‐poly(ϵ‐caprolactone) (PE‐g‐PCL) were synthesized. The 13C NMR analysis of PE‐g‐PPG suggested that all the hydroxyl groups were consumed for propylene oxide polymerization, and transmission electron microscopy demonstrated nanoorder phase separation and indistinct phase boundaries. 13C NMR and gel permeation chromatography analyses indicated the formation of PE‐g‐PCL, in which 36–80 mol % of the hydroxyl groups worked as initiators for ϵ‐caprolactone polymerization. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3657–3666, 2003
Dielectric assembly of a collagen‐model polypeptide in a triple helix
Authors: Imanishi Yukio , Kawazoe Naoki , Ichizawa Kensuke 
Published: October 2003

AbstractIn expectation of the formation of a thermally stable, dielectric supramolecular assembly of a polypeptide with an amino acid sequence similar to that of type‐2 collagen, a sequential polypeptide consisting of the repetition of the Pro‐Pro‐Gly tripeptide was synthesized by solid‐phase synthesis. Column chromatography of an ethanol solution of (Pro‐Pro‐Gly)10NH2 showed the presence of a double helix or triple helix of the polypeptide. The pattern of a circular dichroism (CD) spectrum of an ethanol solution of (Pro‐Pro‐Gly)10NH2 was very similar to that of an aqueous solution of (Pro‐Pro‐Gly)10OH, strongly suggesting the presence of a triple helix of the polypeptide in ethanol. An oriented monolayer assembly of (Pro‐Pro‐Gly)10NH2 was formed on a thin gold film. The distribution of surface unevenness and the surface potential were investigated with Kelvin force microscopy. The rising spots carried an electric potential from room temperature to 150 °C. The correspondence showed the usefulness of the oriented monolayer of the sequential polypeptide materials for thermally stable, dielectric nanodevices. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3632–3639, 2003
Solvent‐induced switching of the macromolecular helicity of poly[(4‐carboxyphenyl)acetylene] induced by a single chiral amino alcohol
Authors: Maeda Katsuhiro , Morino Kazuhide , Yashima Eiji 
Published: October 2003

AbstractCis–transoidal poly[(4‐carboxyphenyl)acetylene] (poly‐1) complexed with optically active amines and amino alcohols showed an induced circular dichroism (ICD) in the ultraviolet–visible region because of a predominantly one‐handed helix formation in water and in dimethyl sulfoxide (DMSO). The Cotton effect signs of the poly‐1/chiral amino alcohol complexes were inverted in the presence of water, whereas the ICD pattern of the poly‐1/chiral amine complexes showed no change, regardless of the water content. These results demonstrated that the helix sense of poly‐1 induced by optically active amino alcohols through noncovalent acid–base interactions could be switched by changes in the solvent ratio in the DMSO–water mixtures. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3625–3631, 2003