bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrogen—Oxygen Flame as a Radical Source for Aqueous‐Phase Reaction: Carboxylation of Propylamine in Aqueous Formic Acid Solution
Authors: Nomoto Shinya , Yoshimura Daisuke , Hagiwara Masayosi , Kozono Masaki , Terasaki Masanori , Oba Masahiro , Shiraishi Susumu , Mita Hajime 
Published: March 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Synthesis of Chiral Tetramic Acids Using Activated Derivatives of N‐ Protected α‐Amino Acids as Precursors: Structural Characterization of Tetramic aci‐Complexes with Metal Ions
Authors: Markopoulos J. , Detsi A. , Gavrielatos E. , Athanasellis G. , Igglessi‐Markopoulou O. 
Published: March 2005

AbstractFor Abstract see ChemInform Abstract in Full Text.
Serotonin 5‐HT4 receptors and their mRNAs in rat and guinea pig brain: Distribution and effects of neurotoxic lesions
Authors: Vilaró M. Teresa , Cortés Roser , Mengod Guadalupe 
Published: March 2005

AbstractSerotonin 5‐HT4 receptors are widely distributed in the periphery and in brain, where they modulate the release of various neurotransmitters and have been implicated in learning and memory. Nine C‐terminal splice variants of this receptor have been cloned in mammalian species. In the rat, three such variants have been described: 5‐HT4(a), 5‐HT4(b), and 5‐HT4(e). In the present study, we have examined several aspects of the distribution of these receptors in brain. First, we provide, in rat and guinea pig, a detailed comparison of the distribution of 5‐HT4 receptors labeled by the antagonist [125I]‐SB 207710 with the distribution of their encoding mRNA visualized by in situ hybridization histochemistry (ISHH). The results suggest that, in several projection systems (striato‐nigral and striato‐pallidal pathways, projection from dentate granule cells to field CA3, habenulo‐interpeduncular pathway), 5‐HT4 receptors are located both somatodendritically and axonally. Second, we have analyzed the distribution of mRNA for the three known rat splice variants by reverse transcription‐polymerase chain reaction (RT‐PCR) and by ISHH. RT‐PCR indicates that all three variants are widely distributed, with 5‐HT4(b) mRNA being present in all regions examined (olfactory tubercle, striatum, hippocampus, inferior colliculus, substantia nigra, parietal cortex) and 5‐HT4(a) and 5‐HT4(e) showing a somewhat more restricted distribution. In other regions (periaqueductal gray, reticular formation, medial septum, diagonal band), faint ISHH signals are observed for 5‐HT4(a)+4(e) mRNAs, whereas 5‐HT4(b) mRNA signals are almost undetectable. Finally, neurotoxic lesions of basal ganglia components in guinea pig also indicate a location of these receptors on terminals of striatal projection neurons. J. Comp. Neurol. 484:418–439, 2005. © 2005 Wiley‐Liss, Inc.
Indoor optical wireless systems employing dual header pulse interval modulation (DH‐PIM)
Authors: Aldibbiat N. M. , Ghassemlooy Z. , McLaughlin R. 
Published: March 2005

AbstractThis paper assesses the performance of dual header pulse interval modulation (DH‐PIM) over indoor optical wireless systems. DH‐PIM being anisochronous scheme offers a built‐in symbol synchronization capability. Theoretical and simulation results demonstrate that DH‐PIM offers shorter symbol length, improved transmission rate and bandwidth requirement and a comparable power spectral density profile compared with digital pulse interval modulation (DPIM) and pulse position modulation (PPM) schemes.It is shown that DH‐PIM2, with wider pulse duration is the preferred option when the available channel bandwidth is limited and higher optical power is tolerable. Whereas DH‐PIM1, with narrower pulse width, exhibits comparable power requirements but a marginally higher bandwidth compared with DPIM, and is also more bandwidth efficient than PPM at the cost of increased power requirement. However, at higher bit resolutions, i.e. M⩾7, DH‐PIM1 is both bandwidth and power efficient compared with PPM. Error rate analysis show that DH‐PIM offers improved packet error rate compared with on‐off‐keying (OOK) and DPIM, but marginally inferior as compared with PPM. The power requirement and penalty due to intersymbol interference for non‐dispersive and dispersive channels is analysed and the results show that for given parameters, DH‐PIM requires marginally higher optical power compared with PPM and DPIM, but it supports the same bit rate at much less bandwidth requirement. Copyright © 2005 John Wiley & Sons, Ltd.
Design of communication protocols using a message transfer pattern
Authors: Byun YoungJoon , Sanders Beverly A. , Keum Chang‐Sup 
Published: March 2005

AbstractDesign patterns help to improve software quality and reduce development cost by reusing experience of experts for recurring problems. Patterns have potential to be useful in almost all areas of software systems, but to date they are mainly concentrated on the development of object‐oriented systems. In this paper, we apply the pattern concept to the description of communication protocols, particularly focusing on message interaction. We hypothesize that many communication protocols can be developed using a few recurring patterns to obtain an initial design description of a system. For the protocol description, we propose a set of patterns which are grouped in two categories: structural and behavioural patterns. A complex protocol can be obtained by composing such patterns. To show the usefulness of our patterns in a realistic application, we perform a case study for an ATM signalling protocol design. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis of (1,2,4‐Oxadiazole)palladium(II) Complexes by [2 + 3] Cycloaddition of Nitrile Oxides to Organonitriles in the Presence of PdCl2
Authors: Bokach Nadezhda A. , Kukushkin Vadim Yu. , Haukka Matti , Pombeiro Armando J. L. 
Published: March 2005

AbstractThe reaction between the nitrile oxides 2,4,6‐R3C6H2CNO (R = Me, OMe) andtrans‐[PdCl2(RCN)2], or RCN (R = Me, Et, CH2CN, NMe2, Ph) in the presence of PdCl2, proceeded smoothly under mild conditions and allowed the isolation of the 1,2,4‐oxadiazole complexestrans‐[PdCl2{Na=C(R)‐ON=Cb(C6H2R3)(Na–Cb)}2] (1–8) in 40–85 % yields. In CH2Cl2, the reaction between 2,4,6‐R3C6H2CNO and [PdCl2(MeCN)2] furnishes [PdCl2(ONCC6H2R3)2] (9and10), which are the first representatives of metal compounds where nitrile oxides act as ligands. The 1,2,4‐oxadiazole complexes1–8were characterized by elemental analysis, FAB mass spectrometry, and IR,1H and13C{1H} NMR spectroscopy, while2,3,7, and8were additionally characterized by X‐ray crystallography. The liberation of the heterocyclic species from1–8was successfully performed by substitution reaction either with 1,2‐bis(diphenylphosphanyl)ethane or with an excess amount of Na2S·7H2O in MeOH; the liberated 1,2,4‐oxadiazoles (11–18) were characterized by positive‐ion FAB mass spectrometry and1H and13C{1H} NMR spectroscopy. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Neighbouring‐Group Effects in Heck Reactions
Authors: Oestreich Martin 
Published: March 2005

AbstractThe Heck reaction is a widely used carbon–carbon bond forming process in organic synthesis. A prominent variant that has found widespread application in targeted complex‐molecule synthesis is the asymmetric intramolecular Heck reaction. This methodology has outshone another powerful facet of Heck chemistry that has been prospering in recent years, namely heteroatom‐directed Heck reactions. Initially designed to achieve high regiocontrol in intermolecular reactions, this technique has recently been successfully applied to highly diastereoselective and even enantioselective substrate‐directed inter‐ as well as intramolecular Heck reactions. This microreview delineates, for the first time, the evolution of this chemistry from regio‐ to diastereo‐ and, finally, enantioselective transformations. Flexible syntheses ofstereodefined, multi‐arylated alkenes, the diastereoselective construction of tertiary and quaternary carbon centres, as well as combining substrate‐ with catalyst‐control in anenantioselective transformation are covered. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Copper‐Catalysed, Enantioselective Desymmetrisation of meso Cyclic Allylic Bis(diethyl phosphates) with Organozinc Reagents
Authors: Piarulli Umberto , Daubos Philippe , Claverie Christelle , Monti Chiara , Gennari Cesare 
Published: March 2005

AbstractA highly regio‐, diastereo‐ and enantioselective desymmetrization of five‐, six‐, and seven‐membered meso, cyclic allylic bis(diethyl phosphates) (3–5) with organozinc reagents was developed, using catalytic amounts (10 mol%) of [Cu(OTf)]2·C6H6 and two different classes of chiral ligands: Schiff bases 1 and phosphoramidites 2. Good to excellent enantioselectivities were obtained for every substrate by a subtle balance of ligand structure and experimental conditions. In particular, ee’s of up to 88 % were obtained for the five‐membered ring substrate 3 with ligands 1cjo and 1cjm using Et2Zn (94 % ee with Me2Zn, 88 % ee with nBu2Zn). Schiff‐base ligands 1 were not effective with the six‐ and seven‐membered substrates 4 and 5. The use of phosphoramidite ligands 2 afforded ee’s of up to 94 % (Et2Zn) for the six‐membered ring product 7, and virtually only one enantiomer (ee ≥ 98 %, with Et2Zn) for the seven‐membered ring product 8. In addition, the desymmetrisation of the conduritol derivative 10 was obtained, with ee’s of up to 86 %. In this case, a fully functionalised cyclohexane derivative, containing four contiguous stereocentres and a double bond, was obtained as a single diastereomer and in high enantiomeric excess from an achiral starting material. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Defining hydrochemical evolution of streamflow through flowpath dynamics in Kawakami headwater catchment, Central Japan
Authors: Subagyono Kasdi , Tanaka Tadashi , Hamada Yohei , Tsujimura Maki 
Published: March 2005

AbstractThe hydrochemical behaviour of catchments is often investigated by inferring stream chemistry through identification of source areas involved in hydrograph separation analysis, yet its dynamic evolution of hydrologic pathways has received little attention. Intensive hydrometric and hydrochemical measurements were performed during two different storms on March 29, 2001 and August 21–22, 2001 to define hydrochemical evolution under the dynamic of flow pathways in a 5·2 ha first‐order drainage of the Kawakami experimental basin (KEB), Central Japan, a forested headwater catchment with various soil depths (1·8 to 5 m) overlying late Neogene of volcanic bedrocks. The hydraulic potential distribution and flow lines data showed that the change in flow direction, which was controlled by rainfall amount and antecedent wetness of the soil profile, agreed well with the hydrochemical change across the slope segment during the storm. Hydrograph separation predicted by end‐member mixing analysis (EMMA) using Ca2+ and SiO2 showed that near surface riparian, hillslope soil water and deep riparian groundwater were important in stream flow generation. The evidence of decrease in solutes concentration at a depth of 1 m in the hillslope and 0·6 m in the near surface riparian during peak storm suggested a flushing of high solutes concentration. Most of the solutes accumulated in the deep riparian groundwater zone, which was due to prominent downward flow and agreed well with the residence time. The distinct flow pathways and chemistry between the near surface riparian and deep riparian groundwater zones and the linkage hillslope aquifer and near surface riparian reservoir, which controls rapid flow and solutes flushing during the storm event, are in conflict with the typical assumption that the whole riparian zone resets flow pathways and chemical signature of hillslope soil water, as has been reported in a previous study. Copyright © 2005 John Wiley & Sons, Ltd.
Advanced glycation end‐product‐induced mitogenesis and collagen production are dependent on angiotensin II and connective tissue growth factor in NRK‐49F cells
Authors: Lee Chu‐I , Guh Jinn‐Yuh , Chen Hung‐Chun , Hung Wen‐Chun , Yang Yu‐Lin , Chuang Lea‐Yea 
Published: March 2005

AbstractDiabetic nephropathy (DN) is characterized by glomerulopathy and tubulointerstitial expansion followed by renal fibrosis. Angiotensin II (Ang II) and connective tissue growth factor (CTGF) are involved in the pathogenesis of DN, while Janus kinase 2 (JAK2) is important in advanced glycation end‐product (AGE)‐induced effects in renal interstitial (NRK‐49F) fibroblasts. Thus, we studied the role of Ang II, CTGF, and JAK2 in AGE‐induced effects in NRK‐49F cells. We found that AGE (150 μg/ml) increased mitogenesis and type I collagen production at 7 days while Ang II (10−7M) increased mitogenesis and type I collagen production at 3 days. We also found that AGE (150 μg/ml) increased angiotensinogen protein at 2 days, which was attenuated by AG‐490 (a JAK2 inhibitor). AGE (150 μg/ml) increased CTGF mRNA and protein expression at 3 and 5 days, respectively. Ang II (10−7M) increased CTGF mRNA and protein expression at 1 and 2 days, respectively, which were attenuated by AG‐490. Moreover, losartan (a type I angiotensin receptor blocker) and captopril (an angiotensin converting enzyme inhibitor) attenuated AGE‐induced CTGF mRNA/protein expression while attenuating AGE‐induced mitogenesis and type I collagen production. AG‐490 and CTGF antisense (but not sense) oligodeoxynucleotide (ODN) attenuated Ang II (10−7M) and AGE‐induced mitogenesis and type I collagen production at 3 and 7 days, respectively. We concluded that AGE (150 μg/ml)‐induced mitogenesis and type I collagen production are dependent on the Ang II‐JAK2‐CTGF pathway in NRK‐49F cells. Moreover, Ang II‐induced mitogenesis and type I collagen production are dependent on the JAK2‐CTGF pathway. © 2005 Wiley‐Liss, Inc.
An improved nucleic acid parameter set for the GROMOS force field
Authors: Soares Thereza A. , Hünenberger Philippe H. , Kastenholz Mika A. , Kräutler Vincent , Lenz Thomas , Lins Roberto D. , Oostenbrink Chris , van Gunsteren Wilfred F. 
Published: March 2005

AbstractOver the past decades, the GROMOS force field for biomolecular simulation has primarily been developed for performing molecular dynamics (MD) simulations of polypeptides and, to a lesser extent, sugars. When applied to DNA, the 43A1 and 45A3 parameter sets of the years 1996 and 2001 produced rather flexible double‐helical structures, in which the Watson–Crick hydrogen‐bonding content was more limited than expected. To improve on the currently available parameter sets, the nucleotide backbone torsional‐angle parameters and the charge distribution of the nucleotide bases are reconsidered based on quantum‐chemical data. The new 45A4 parameter set resulting from this refinement appears to perform well in terms of reproducing solution NMR data and canonical hydrogen bonding. The deviation between simulated and experimental observables is now of the same order of magnitude as the uncertainty in the experimental values themselves. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 725–737, 2005
LC‐PDA and LC‐ESI‐MS separation and determination of process‐related substances arising from stilbene‐type fluorescent whitening agents. Application to monitoring of their photodegradation products in industrial effluents and aqueous environmental systems
Authors: Rao R. Nageswara , Venkateswarlu N. , Khalid Sara , Narsimha R. 
Published: March 2005

AbstractA simple and rapid gradient elution high‐performance liquid chromatographic method using photodiode array and electrospray ionization mass spectrometric detectors was developed for separation and determination of the process‐related substances and photodegradation products of stilbenesulfonic acids, viz. 4,4´‐dinitrostilbene‐2,2´‐disulfonic acid (DNSDA), 4‐amino‐4´‐nitrostilbene‐2,2´‐disulfonic acid (ANSDA), and 4,4´‐diaminostilbene‐2,2´‐disulfonic acid (DASDA) in industrial waste waters. Gradient elution was carried out using ammonium acetate and acetonitrile as mobile phase and an Inertsil‐ODS 3V column for separation. The negative‐ion electrospray ionization mass spectra containing [M–H]– ions of sulfonic acids allowed molecular mass determination of unknowns and the structures were proposed on the basis of the fragment ions in the MS/MS spectra.
Thioacetamide chemically immobilized on silica gel as a solid phase extractant for the extraction and preconcentration of copper(II), lead(II), and cadmium(II)
Authors: Xie Zeng Hong , Xie Fa Zhi , Guo Liang Qia , Lin Xu Cong , Chen Guo Nan 
Published: March 2005

AbstractThioacetamide immobilized on silica gel was prepared via the Mannich reaction. The extraction and enrichment of copper(II), lead(II), and cadmium(II) ions from aqueous solutions has been investigated. Conditions for effective extraction are optimized with respect to different experimental parameters in both batch and column processes prior to their determination by flame atomic absorption spectrometry (FAAS). The optimum pH ranges for quantitative adsorption are 4.0–8.0, 2.0–7.0, and 5.0–10.0 for Pb(II), Cu(II), and Cd(II), respectively. Pb(II) and Cd(II) can be desorbed with 3 mol/L and 0.1 mol/L HCl/HNO3, and Cu(II) can be desorbed with 2.5% thiourea. The adsorption capacity of the matrix has been found to be 19.76, 16.35, and 12.50 mg/g for Pb(II), Cu(II), and Cd(II), respectively, with the preconcentration factor of ≈300 for Pb(II) and ≈200 for Cu(II) and Cd(II). Analytical utility is illustrated in real aqueous samples generated from distilled water, tap water, and river water samples.
Homoleptic lanthanide guanidinate complexes: The effective initiators for the polymerization of trimethylene carbonate and its copolymerization with ε‐caprolactone
Authors: Zhou Liying , Sun Hongmei , Chen Jinglei , Yao Yingming , Shen Qi 
Published: March 2005

AbstractThe ring‐opening polymerization of trimethylene carbonate (TMC) using homoleptic lanthanide guanidinate complexes [RNC(NR′2)NR]3Ln as single component initiators has been fully investigated for the first time. The substituents on guanidinate ligands and center metals show great effect on the catalytic activities of these complexes, that is, N(CH2)5 > NiPr2 > NPh2 (for R′), Cy > iPr (for R), and Yb > Sm > Nd. Among them, [Ph2NC(NCy)2]3Yb shows the highest catalytic activity. Some features and kinetic behaviors of the TMC polymerization initiated by [Ph2NC(NCy)2]3Yb were studied in detail. The polymerization rate is first order, with the monomer concentration and Mn of the polymer increasing with the polymer yield increasing linearly. The results indicated the present system having “living character.” A mechanism that the polymerization occurs via acyl‐oxygen bond cleavage rather than alkyl‐oxygen bond cleavage was proposed. The copolymerization of TMC with ϵ‐caprolactone (ε‐CL) initiated by [Ph2NC(NCy)2]3Yb was also tested. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1778–1786, 2005
Syntheses and characterizations of aniline/butylthioaniline copolymers: Comparisons of copolymers prepared by the new concurrent reduction and substitution route and the conventional oxidative copolymerization method
Authors: Han Chien‐Chung , Yang Ku‐Feng , Hong Shih‐Ping , Balasubramanian Arumugam , Lee Yi‐Te 
Published: March 2005

AbstractNew highly solution‐processable aniline/butylthioaniline copolymers were prepared via oxidative copolymerization (OCP) and by concurrent reduction and substitution (CRS). Butylthio‐substituted polyaniline obtained via the CRS route (Pan‐SBu), being in line with the expected property changes after the addition of an electron‐donating substituent to an aromatic ring, displayed a lowered redox potential (E0) and a redshifted maximum wavelength (λmax; ultraviolet–visible) in comparison with its parent unsubstituted polyaniline (Pan). However, copolymers CP1–CP4 (obtained via the OCP method) displayed opposite behaviors, showing higher E0 values and blueshifts in λmax than the unsubstituted Pan. The results suggested that CP1–CP4 had shorter conjugation lengths than the unsubstituted Pan, possibly because of their chain conjugation defects (e.g., 1,3‐ring linkage structures), as evidenced by IR studies. The results of 1H NMR studies also indicated that Pan‐SBu had much higher structural homogeneity than copolymer CP4. Because the CRS synthetic route involved no backbone alternations, the resultant copolymer (Pan‐SBu) should have maintained the same backbone structure and hence the high conductivity of the parent unsubstituted Pan. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1767–1777, 2005
Ground‐ice stratigraphy and formation at North Head, Tuktoyaktuk Coastlands, western Arctic Canada: a product of glacier–permafrost interactions
Authors: Murton Julian B. 
Published: March 2005

AbstractGlacially deformed permafrost at North Head, in the Tuktoyaktuk Coastlands of western Arctic Canada, contains a complex ground‐ice stratigraphy that formed during the course of the last glacial–interglacial cycle. Two generations of ground ice are distinguished within a single stratigraphic sequence. Pre‐deformation ice has been glacially deformed or eroded beneath the cold‐based margin of the Laurentide Ice Sheet (LIS) during Marine Isotope Stage 2. Such ice comprises (1) buried basal ice, (2) massive segregated ice and (3) ice clasts subglacially eroded from pre‐existing ground ice. In contrast, post‐deformation ice has not been glacially disturbed because it formed during or after deglaciation; it includes (4) dykes and sills of intrusive ice, (5) massive segregated‐intrusive ice, (6) ice wedges and composite wedges, (7) segregated ice and (8) pool ice.The superimposition of post‐deformation intrusive ice and massive segregated‐intrusive ice into permafrost containing pre‐deformation ground ice indicates that substantial quantities of overpressurized water were injected into ice‐marginal permafrost during or after deglaciation. The required external water source for the post‐deformation intrusive ice was probably overpressurized subpermafrost groundwater in front of the retreating margin of the LIS. Injection of this water into proglacial permafrost hydraulically fractured the permafrost and formed ice dykes, ice sills and massive segregated‐intrusive ice.A two‐stage model of massive‐ice development can be reconciled with known permafrost and glacial conditions in the ice‐marginal context of the Late Wisconsinan LIS. The model probably applies to some other glaciated terrains of the western Canadian Arctic. Copyright © 2005 John Wiley & Sons, Ltd.