bluuebunny/crossref_metadata_2025_split huggingface dataset:
Theoretical Analysis of Pyridine Protonation in Water Clusters of Increasing Size
Authors: Sicilia M. Carmen , Muñoz‐Caro Camelia , Niño Alfonso 
Published: December 2004

AbstractThe protonation of pyridine in water clusters as a function of the number of water molecules was theoretically analyzed as a prototypical case for the protonation of organic bases. We determined the variation of structural, bonding, and energetic properties on protonation, as well as the stabilization of the ionic species formed. Thus, we used supermolecular models in which pyridine interacts with clusters of up to five water molecules. For each complex, we determined the most stable unprotonated and protonated structures from a simulated annealing at the semi ab initio level. The structures were optimized at the B3LYP/cc‐pVDZ level. We found that the hydroxyl group formed on protonation of pyridine abstracts a proton from the ortho‐carbon atom of the pyridine ring. The “atoms in molecules” theory showed that this CH group loses its covalent character. However, starting with clusters of four water molecules, the CH bond recovers its covalent nature. This effect is associated with the presence of more than one ring between the water molecules and pyridine. These rings stabilize, by delocalization, the negative charge on the hydroxyl oxygen atom. Considering the protonation energy, we find that the protonated forms are increasingly stabilized with increasing size of the water cluster. When zero‐point energy is included, the variation follows closely an exponential decrease with increasing number of water molecules. Analysis of the vibrational modes for the strongest bands in the IR spectra of the complexes suggests that the protonation of pyridine occurs by concerted proton transfers among the different water rings in the structure. Symmetric water stretching was found to be responsible for hydrogen transfer from the water molecule to the pyridine nitrogen atom.
NOD mice have a severly impaired ability to recruit leukocytes into sites of inflammation
Authors: Bouma Gerben , Nikolic Tatjana , Coppens Jojanneke M. C. , van Helden‐Meeuwsen Cornelia G. , Leenen Pieter J. M. , Drexhage Hemmo A. , Sozzani Silvano , Versnel Marjan A. 
Published: December 2004

AbstractThe accumulation of macrophages (MΦ) and dendritic cells (DC) in the pancreas plays a crucial role in the pathogenesis of autoimmune diabetes. We studied the recruitment of monocytes, MΦ and DC to sites of inflammation, i.e. the peritoneal cavity and a subcutaneously elicited air pouch in the NOD mouse model of autoimmune diabetes. The leukocyte recruitment was studied from 1 to 7 days after injection of thioglycollate (peritoneum), C5a (peritoneum, air pouch), CCL2 and CCL3 (air pouch). C57BL/6 and BALB/c mice served as controls. Morphological and flow cytometric analysis of the recruited cells was performed, IL‐1β, TNF‐α, IL‐6, IL‐12 and IL‐10 in exudates measured, and in vitro CCL2‐chemotaxis of exudate MΦ (Boyden chamber) determined. NOD mice were strongly impaired in the recruitment of MΦ, DC, monocytes, and granulocytes. Chemokine‐injected air pouches of NOD mice showed an increased IL‐10 and a decreased IL‐1β level, while the other cytokines were normally or very lowly expressed. In addition, NOD exudate MΦ displayed an impaired in vitro CCL2‐induced migration. Our data show that NOD mice have an impaired ability to recruit leukocytes into sites of inflammation elicited in the peritoneum and the air pouch. A raised IL‐10/IL‐1β ratio at these sites and a deficient migratory capacity of NOD monocytes are important determinants in this impairment.
DNA vaccines prime CD8+ T cell responses to epitopes of viral antigens produced from overlapping reading frames of a single coding sequence
Authors: Fissolo Nicolas , Riedl Petra , Reimann Jörg , Schirmbeck Reinhold 
Published: December 2004

AbstractA hepatitis B virus (HBV)‐derived sequence that encodes the 832‐residue polymerase (Pol) protein of HBV in the primary open reading frame (ORF), and the three (large, middle and small) hepatitis B surface antigen (HBsAg) variants in an alternative ORF was used. This sequence was cloned into expression vectors in which Pol was expressed under heterologous (HCMV, SV40 or metallothionin) promoter control. Some Pol‐encoding vectors coexpressed Pol as well as readily detectable amounts of HBsAg. Efficient HBsAg expression depended on endogenous HBV promoter sequences but was apparently also facilitated by heterologous promoter sequences located upstream of the HBV Pol sequence. DNA immunization of mice efficiently coprimed CD8+ T cell responses to epitopes of Pol and HBsAg. Over expression of Pol (using an hsp73‐facilitated expression system) did not correlate with the immunogenicity of the Kd/Pol140–148 epitope. Immunodominant Ld‐restricted CD8+ T cell responses to HBsAg down‐modulated priming of CD8+ T cell responses to other HBsAg epitopes but not to the Kd/Pol140–148 epitope. Different antigens transcribed from alternative reading frames of a single sequence in a DNA vaccine can thus efficiently prime multispecific T cell responses.
A Novel Dinuclear FeII Spin‐Crossover Complex Based on a 2,2‐Bipyrimidine Bridge Ligand: [Fe(CH3bipy)(NCS)2]2bpym
Authors: Gaspar Ana B. , Ksenofontov Vadim , Martinez Víctor , Muñoz M. Carmen , Real José A. , Gütlich Philipp 
Published: December 2004

AbstractThe dinuclear iron(II) complex {[Fe(CH3bipy)(NCS)2]2bpym} has been synthesised and its crystal structure determined at 293 K. The magnetic properties display intramolecular antiferromagnetic coupling at 1 bar (J = −4.2 cm−1), and the onset of a pressure‐induced spin conversion is observed at 11 kbar. Magnetic field Mössbauer measurements have been carried out at 4.2 K, and indicate that the HS species correspond to [HS‐HS] pairs. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Synthesis of (Indenylidene)phosphoranes − A Novel Class of Ligand Precursors for Main‐Group and Transition Metal Organometallics
Authors: Rufanov Konstantin A. , Ziemer Burkhard , Hummert Markus , Schutte Stefan 
Published: December 2004

AbstractIndPPh2 (1) reacts with RCH2Br to form the phosphonium salts [RCH2P(Ph)2Ind]+Br− (2: R = Ph; 3: R = C6F5) in high yields. Oxidation of 1 with H2O2 in THF proceeds smoothly to give the phosphane oxide IndP(O)Ph2 (4). Dehydrobromination of 2 and 3 with NaH in THF yields the corresponding indenylidenephosphoranes C9H6=P(Ph)2CH2R (5: R = Ph; 6: R = C6F5). Further deprotonation of 6 with excess NaH results in formation of sodium 1‐{[(pentafluorophenyl)methylidene]diphenylphosphoranyl}indenide (7), isolated as a solvate with three THF molecules. A detailed NMR study of new ligand precursors and X‐ray structure studies of 5 and 7 have been accomplished. A short F→Na coordination contact in the molecular structure of 7 has been detected. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
E1‐Ngn2/Cre is a new line for regional activation of Cre recombinase in the developing CNS
Authors: Berger Joachim , Eckert Silke , Scardigli Raffaella , Guillemot François , Gruss Peter , Stoykova Anastassia 
Published: December 2004

AbstractWe generated a transgenic mouse line named E1‐Ngn2/Cre that expresses Cre recombinase and GFP under the control of the E1 enhancer element of the gene Ngn2 (Scardigli et al.: Neuron 31:203–217, 2001). Cre‐recombinase activity and GFP fluorescence are consistent with the reported expression pattern controlled by the E1‐Ngn2 enhancer. Recombination was detected in the progenitor domains p1 and p2 in the ventricular zone of the neural tube and in distinct domains of the pretectum, the dorsal and ventral thalamus, the tegmentum of the mesencephalon, and the hindbrain. In the developing cortex, Cre‐recombinase activity is confined to a subpopulation of progenitors predominantly in the region of the ventral and lateral pallium. The E1‐Ngn2/Cre mouse line thus provides an excellent novel tool for a region‐specific conditional mutagenesis in the developing CNS. genesis 40:195–199, 2004. © 2004 Wiley‐Liss, Inc.
Unique contribution of heat shock transcription factor 4 in ocular lens development and fiber cell differentiation
Authors: Min Jin‐Na , Zhang Yan , Moskophidis Demetrius , Mivechi Nahid F. 
Published: December 2004

AbstractMammalian ocular lens development results via a differentiation program that is highly regulated by tissue‐specific transcription factors. Central to this is the terminal differentiation of fiber cells, which develop from epithelial cells on the anterior surface of the lens, accompanied by a change in cell shape and expression of structural proteins (such as membrane proteins MP19, MIP26, connexin 43, 46, and 50, cytoskeletal proteins CP49, CP115, and α, β, and γ crystallins), creating a transparent, refractive index gradient in the lens. Mutations in genes controlling eye development and in lens structural protein genes are associated with multiple ocular developmental disorders, including cataracts and other opacities of the lens. Here we show that heat shock transcription factor 4 (HSF4) expression in the developing lens is required for correct lens development and that inactivation of hsf4 leads to early postnatal cataract formation with primary effects specific to terminal fiber cell differentiation. These data suggest that HSF4 acts as a critical transcription factor for lens‐specific target gene expression, in particular regulating the small 25 kDa heat shock protein that acts as a modifier for lens opacity and cataract development. Thus, HSF4 fulfills a central role in controlling spatial and temporal expression of genes critical for correct development and function of the lens. genesis 40:205–217, 2004. © 2004 Wiley‐Liss, Inc.
Comparison of osteoblast responses to hydroxyapatite and hydroxyapatite/soluble calcium phosphate composites
Authors: Ogata Korenori , Imazato Satoshi , Ehara Atsushi , Ebisu Shigeyuki , Kinomoto Yoshifumi , Nakano Takayoshi , Umakoshi Yukichi 
Published: December 2004

AbstractHydroxyapatite/soluble calcium phosphate composites (HAp/SCaP) are novel HAp‐based materials with enhanced solubility that have been developed by annealing HAp in a vacuum. This study compared the effects of HAp and HAp/SCaP on osteoblast proliferation, differentiation, and mineralization using an MC3T3‐E1 cell culture system. MC3T3‐E1 cells were cultured on HAp or HAp/SCaP, and the number of attached cells and their morphology were examined. The influence of the extract from HAp/SCaP on osteoblast differentiation was determined by the measurement of alkaline phosphatase activity and reverse transcriptase‐polymerase chain reaction analysis of the expression of osteoblastic markers. In addition, mineralization was evaluated by the staining of calcium deposits with Alizarin red. Attachment of a greater number of cells exhibiting no degeneration in their morphology was observed on HAp/SCaP compared with HAp after incubation for 7 days or more. Culturing cells with the extract from HAp/SCaP resulted in promotion of alkaline phosphatase activity, the expression of type I collagen, and bone‐like tissue formation. The results of the present study indicate that HAp/SCaP shows greater ability in osteogenesis than HAp by increasing collagen synthesis and calcification of the extracellular matrix. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 72A: 127–135, 2005
The effect of pre‐coking on the activity and selectivity of the catalytic cracking of squalane
Authors: Chia DA , Trimm DL 
Published: December 2004

AbstractThe pre‐coking of cracking catalysts has been reported to increase the yield of light cycle oil from fluid catalytic cracking. The present studies investigating an equilibrated catalyst show that this is not the case. The effect of pre‐treating equilibrated catalysts with coke and with ammonia shows that conversion was decreased in both cases and the product selectivity of the process changed. Both coke and ammonia were found to decrease site density, reducing the importance of hydrogen transfer reactions. Increased yields of light cycle oil as a result of pre‐coking can only be expected with fresh catalyst, where small amounts of coke deactivate the most acidic sites. Such sites have already been deactivated on equilibrated catalyst. Copyright © 2004 Society of Chemical Industry
A typology of continuous improvement implementation processes
Authors: Rijnders Sander , Boer Harry 
Published: December 2004

AbstractThis article presents a typology of continuous improvement (CI) implementation processes. The typology is based on an empirical study of 26 companies engaged in the implementation of CI. The data underpinning the typology was collected through retrospective interviews guided by a semi‐structured questionnaire. Four different approaches to implementing CI are identified, described and analysed. The resulting typology contributes to the development of CI implementation theory—an underdeveloped area of theory—and is useful for companies considering to engage in, or step up, their CI activities. Copyright © 2004 John Wiley & Sons, Ltd.
Managing the knowledge landscape of an MNC: knowledge networking at Ericsson
Authors: Magnusson Mats G. 
Published: December 2004

AbstractIn organizations striving for continuous innovation, the deliberate handling of knowledge plays a fundamental role. This far, most knowledge management initiatives have consisted of the implementation of new IT tools allowing for more efficient information handling. This approach has been criticized, as it does not consider certain aspects of knowledge, e.g. tacitness, social embeddedness and the creation of new knowledge. Alternative knowledge management approaches based on a more comprehensive notion of knowledge have been called for, but few examples of what these could look like in practice have been given. One example of an attempt to manage knowledge in a more holistic manner is knowledge networking. Based on case studies of seven different knowledge networking initiatives within Ericsson, the key components of the overall approach are described and some of the challenges posed to management are identified. Key issues that need to be attended to when designing and implementing individual knowledge networking initiatives are the extension and focus of user groups, the role of management in the initiatives and the promotion of knowledge‐sharing behaviour throughout the organization. Ericsson's knowledge networking strategy aims at developing a loosely coupled structure of nuclei for knowledge creation and sharing, connected to each other by different kinds of knowledge directories. This appears to have some advantages compared to traditional knowledge management strategies, as it supports the creation and sharing of both tacit and explicit knowledge. Furthermore, its strong focus on locally developed initiatives and knowledge directories may offer a more dynamic support structure than traditional top‐down initiatives focusing primarily on knowledge repositories. Copyright © 2004 John Wiley & Sons, Ltd.
Corrosion fatigue of spot‐welded austenitic stainless steels in 3.5% NaCl solution
Authors: Somervuori M. E. , Alenius M. T. , Hänninen H. E. , Karppi R. 
Published: December 2004

AbstractCorrosion fatigue and fatigue properties of spot‐welded austenitic stainless steels EN 1.4301 and EN 1.4318 in 2B or 2F and 2H conditions were investigated in 3.5% sodium chloride (NaCl) solution and in air. The shear‐loaded specimens were single spot overlap joints.The effect of steel grade, load, frequency, temperature and type of chloride on fatigue strength of the 1.0 mm thick steel specimens was evaluated by using the Taguchi Method®. Increase of the load, rise of temperature and lowering of the frequency accelerate corrosion fatigue of the spot‐welded steel samples. Type of chloride had only a minor effect on fatigue strength. The 2B grade spot‐welded steel samples exhibited better fatigue strength than the 2H grade samples of the same steels.On the basis of the results obtained by the Taguchi Method® the S‐N curves were defined for the spot‐welded 1.9 mm thick steels in 3.5% sodium chloride solution at 50°C. For reference the fatigue experiments were performed in air at the ambient temperature. Comparison of the results shows that corrosive environment decreases remarkably the fatigue strength of the spot‐welded steels. The EN 1.4301 2H and EN 1.4318 2H steels have no distinctive difference in their corrosion fatigue strength even though they show a different fatigue behaviour in air.The microscopic investigations indicate that the fatigue cracks in the spot welds initiate from either side of the recrystallised area in the HAZ outside the spot‐weld nugget both in air and in the corrosive environments. Pre‐exposure in the corrosive environment seems to have no major influence on the crack initiation, because the cracks do not initiate at the heat‐tinted area of the crevice where the crevice corrosion occurs.
Corrosion resistance of the high‐strength filler metal NiCr20Fe14Mo11WN (alloy 50 PLUS)
Authors: Brill U. 
Published: December 2004

AbstractThe Nb‐free NiCr20Fe14Mo11WN alloy has been developed as a new filler metal which combines high strength and excellent corrosion resistance in wet environments at ambient temperatures.The alloy is characterized by exceptional resistance to pitting and crevice corrosion, no sensitiveness to chloride induced stress corrosion cracking and shows high mechanical properties, e.g. 0.2 %‐yield strength.Because the alloy is practically free of stable nitride formers like niobium, titanium etc., no nitride formation during welding of super austenitic, duplex and super duplex steels is possible, which proves the alloy to be superior to alloy 625.
Fuzzy cluster analysis constructed by numeric genetic algorithm (NGA) and its use in the evaluation of heterogeneity of temporarily protective oil coating
Authors: Zhong Q. , Rohwerder M. , Chen W. , Liu D. 
Published: December 2004

AbstractA fuzzy cluster analysis based on a numeric genetic algorithm (NGA) was applied for the study of the inhomogeneity of temporarily protective oil coating. Three different types of film behaviour can be assigned to the investigated temporarily protective coating: corrosive, protective and unstable. It is suggested that utilizing this method could evaluate the heterogeneity of temporarily protective oil coating more efficiently, precisely and more comprehensively.
Comparison of four methods for monitoring the kinetics of curing of a phenolic resin
Authors: Malkin A.Ya. , Gorbunova I.Yu. , Kerber M.L. 
Published: December 2004

AbstractThe kinetics of curing of several phenolic resin compounds were studied with the use of four techniques: viscometry, infrared spectroscopy (IR), differential scanning calorimetry (DSC), and thermomechanical analysis. The objective was to compare the effectiveness of these methods. It was found that the viscosity increase during oligomer curing can be described by an exponential function, and that the rate of viscosity increase can be described in terms of a “viscometric” kinetic constant, kη. The gel‐time, t*, was found by extrapolation of the time dependence of the reciprocal viscosity. The product (t*kη) appears to be constant for all temperatures. It was concluded that each experimental technique reflects a different kinetic process, and it is not possible to correlate the results of one technique with those of another. The degree of conversion at the gel point, β*, depends on temperature, and it is thought that this is due to the heterogeneous nature of curing. The glass temperature (as determined from the maximum in the loss tangent) is related to the degree of curing by the DiBenedetto equation, which can be used to determine the degree of conversion during the final stages of the reaction. POLYM. ENG. SCI. 45:95–102, 2005. © 2004 Society of Plastics Engineers
Proteomic analysis of plasma membrane vesicles isolated from the rat renal cortex
Authors: Cutillas Pedro R. , Biber Juerg , Marks Joanne , Jacob Richard , Stieger Bruno , Cramer Rainer , Waterfield Michael , Burlingame Alma L. , Unwin Robert J. 
Published: December 2004

AbstractPolarized epithelial cells are responsible for the vectorial transport of solutes and have a key role in maintaining body fluid and electrolyte homeostasis. Such cells contain structurally and functionally distinct plasma membrane domains. Brush border and basolateral membranes of renal and intestinal epithelial cells can be separated using a number of different separation techniques, which allow their different transport functions and receptor expressions to be studied. In this communication, we report a proteomic analysis of these two membrane segments, apical and basolateral, obtained from the rat renal cortex isolated by two different methods: differential centrifugation and free‐flow electrophoresis. The study was aimed at assessing the nature of the major proteins isolated by these two separation techniques. Two analytical strategies were used: separation by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) at the protein level or by cation‐exchange high‐performance liquid chromatography (HPLC) after proteolysis (i.e., at the peptide level). Proteolytic peptides derived from the proteins present in gel pieces or from HPLC fractions after proteolysis were sequenced by on‐line liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). Several hundred proteins were identified in each membrane section. In addition to proteins known to be located at the apical and basolateral membranes, several novel proteins were also identified. In particular, a number of proteins with putative roles in signal transduction were identified in both membranes. To our knowledge, this is the first reported study to try and characterize the membrane proteome of polarized epithelial cells and to provide a data set of the most abundant proteins present in renal proximal tubule cell membranes.∁
Lu2O3:Yb3+ ceramics – a novel gain material for high‐power solid‐state lasers
Authors: Takaichi K. , Yagi H. , Shirakawa A. , Ueda K. , Hosokawa S. , Yanagitani T. , Kaminskii A. A. 
Published: December 2004

AbstractWe have developed Yb3+:Lu2O3 ceramics with nanocrystalline technology and a vacuum sintering method. A laser diode end‐pumped efficient Yb3+:Lu2O3 ceramic laser was demonstrated. A 0.7 W cw output power was obtained with the slope efficiency of ≈36% at 1035 nm wavelength, and 0.95 W with the slope efficiency of ≈53% at 1079 nm. We classify the Lu2O3:Yb3+ ceramics as gain medium for high‐power solid‐state lasers (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)