bluuebunny/crossref_metadata_2025 huggingface dataset:
Microchemical Engineering: Components, Plant Concepts, User Acceptance – Part II
Authors: Hessel V. , Löwe H.
Published: April 2005

Over the last five years, many activities have focused on the unexploited field of carrying out reactions on small scales. Due to the rapid development of new components, this paper deals with recent developments only in a compressed form. An important point is the analysis of possible plant concepts for microreactors and whether these are a sensible option. Due to the enormous difference in size between the microchannels and the fluid periphery of possible components this is not just a technical question. It touches on the microtechnology concept as a whole. The direction in which the field should be developed and which measures can be taken to influence its development are questions that are addressed here with respect to the big industrial interest in microreactors.
Size Reduction of Metals by Means of Swing‐Hammer Shredders
Authors: Sander S. , Schubert G.
Published: April 2005

Size reduction is of cardinal importance in the recycling of scrap and waste. The choice of size reduction machines is critically dependent on the properties and bonding conditions of the components present in the waste or scrap. Shredders have become widely used for the size reduction of various kinds of scrap. Size reduction of metals in shredders requires sufficiently deformation of the pieces of material (bending to compaction) which leads to cracking. Tensile loads con combination with bending and torsion can enlarge the cracks and ultimately lead to break‐up of the pieces of metal.
Enhancing the Capacity of Static Layer Crystallization Using Mechanical Devices
Authors: Kuszlik A.K.
Published: April 2005

Certain classes of products feature structurally compact and mechanically stable crystal layers, which are able to stand without being supported by the crystallizer plates. Such crystal layers may move away from the warming crystallizer plates, which in turn interferes with the effectiveness of sweating. Using a simple countermeasure like inserting holders into the crystallizer such negative effects can be avoided to a large extent.
Partial Oxidation of Propylene in Sub‐ and Supercritical Water
Authors: Bröll D. , Krämer A. , Vogel H.
Published: April 2005

The motivation for investigating the partial oxidation of propylene in sub‐ and supercritical water arises from the unique physico‐chemical properties of this medium. In sub‐ and supercritical water propylene oxide will react to 1,2‐propandiol, so this one‐step process would be an alternative for the technically established two‐step process via chlorohydrin or indirect epoxidation.
Catalytic Oxidation of Liquid Methanol as a Heat Source for an Automotive Reformer
Authors: Lindström B. , Pettersson L.J.
Published: April 2005

A reactor for catalytically oxidizing liquid methanol has been developed for supplying heat to an automotive reformer. In the tests presented in this paper we show that it is possible to catalytically combust liquid methanol by dispersing the methanol and air by a nebulizer over the catalysts. In the experiments we tested several base and noble metals and found that either platinum or palladium was required at the ignition zone. The tests also showed that it was possible to achieve complete combustion when only 25 % of the catalyst bed contained a noble metal.
Simultaneous Isomerization and Etherification of Isoamylenes with Methanol
Authors: Kiviranta‐Pääkkönen P. , Krause A.O.I.
Published: April 2005

The effect of feed MeOH/2M1B molar ratio on the initial isomerization and etherification rates of 2‐methyl‐1‐butene (2M1B) was studied in a batch reactor. The initial reaction rates for etherification and isomerization increased when the MeOH/2M1B molar ratio decreased. The ratio of etherification and isomerization rate was 2–3 until at lowest initial MeOH/2M1B molar ratio 0.2, where the isomerization rate increased significantly. At MeOH/2M1B molar ratio 0.2 the isomerization reaction rate was twice as high as the etherification reaction rate. Several kinetic formulations were tested to explain this new data and the data obtained in earlier studies. According to the statistics, a kinetic model based on three active sites gave the best fit, but it was discussed that the basic Langmuir‐Hinshelwood mechanism might be more adequate. An improved fit of the Langmuir‐Hinshelwood model was obtained, when a correction factor describing the acceleration of isomerization rate with the molar fraction of 2M1B was added into the kinetic equations.
Structure–Property Correlations in Solid Solutions of (CuI)8P12−xAsx, 2.4≤x≤6.6
Authors: Jayasekera Buddhimathie , Brock Stephanie L. , Lo Andy Y. H. , Schurko Robert W. , Nazri Gholam‐Abbas
Published: April 2005

A series of P/As mixed pnicogen phases of composition (CuI)8P12−xAsx, in which x=2.4, 4.2, 4.8, 5.4, and 6.6, have been synthesized and characterized by X‐ray single crystal and powder diffraction, solid‐state NMR spectroscopy, thermal gravimetric analysis, and impedance spectroscopy. These materials are isostructural to (CuI)8P12 and consist of neutral, tubular P/As mixed pnicogen chains associated with CuI and I− ions. The As is distributed throughout the pnicogen chains; however, the “roof” sites of the [P8] cage show preferred occupation by As relative to the other sites. Accordingly, the change in cell volume is not a linear function of the As incorporation. Solid‐state 31P NMR spectroscopy of the 40 % As incorporated sample are consistent with the X‐ray structural model, with extensive broadening due to 31P–75As coupling and site disorder, and a change in the chemical shifts of the resonances due to the As substitution into the lattice. The degree of copper ion site disorder, probed by single‐crystal X‐ray diffraction, increases with increasing As content. Although very little change is observed in the copper ionic conductivity of polycrystalline samples, which ranges from 1.8–5.1×10−6 S cm−1 for (CuI)8P12−xAsx, x=0, 4.2, 5.4; a single crystal (x=4.8) measured along the needle axis has a conductivity of 1.7×10−3 S cm−1 at 128 °C. This represents an order of magnitude improvement in conductivity over (CuI)8P12 at the same temperature.
Copolymerization of Cyclohexene Oxide with CO2 by Using Intramolecular Dinuclear Zinc Catalysts
Authors: Xiao Youli , Wang Zheng , Ding Kuiling
Published: April 2005

The intramolecular dinuclear zinc complexes generated in situ from the reaction of multidentate semi‐azacrown ether ligands with Et2Zn, followed by treatment with an alcohol additive, were found to promote the copolymerization of CO2 and cyclohexene oxide (CHO) with completely alternating polycarbonate selectivity and high efficiency. With this type of novel initiator, the copolymerization could be accomplished under mild conditions at 1 atm pressure of CO2, which represents a significant advantage over most catalytic systems developed for this reaction so far. The copolymerization reaction was demonstrated to be a living process as a result of the narrow polydispersities and the linear increase in the molecular weight with conversion of CHO. In addition, the solid‐state structure of the dinuclear zinc complex was characterized by X‐ray crystal structural analysis and can be considered as a model of the active catalyst. On the basis of the various efforts made to understand the mechanisms of the catalytic reaction, including MALDI‐TOF mass analysis of the copolymers' end‐groups, the effect of alcohol additives on the catalysis and CO2 pressure on the conversion of CHO, as well as the kinetic data gained from in situ IR spectroscopy, a plausible catalytic cycle for the present reaction system is outlined. The copolymerization is initiated by the insertion of CO2 into the ZnOEt bond to afford a carbonate–ester‐bridged complex. The dinuclear zinc structure of the catalyst remains intact throughout the copolymerization. The bridged zinc centers may have a synergistic effect on the copolymerization reaction; one zinc center could activate the epoxide through its coordination and the second zinc atom may be responsible for carbonate propagation by nucleophilic attack by the carbonate ester on the back side of the cis‐epoxide ring to afford the carbonate. The mechanistic implication of this is particularly important for future research into the design of efficient and practical catalysts for the copolymerization of epoxides with CO2.
Borate‐Catalyzed Reactions of Hydrogen Peroxide: Kinetics and Mechanism of the Oxidation of Organic Sulfides by Peroxoborates
Authors: Davies D. Martin , Deary Michael E. , Quill Kieran , Smith Robert A.
Published: April 2005

The kinetics of the oxidation of substituted phenyl methyl sulfides by hydrogen peroxide in borate/boric acid buffers were investigated as a function of pH, total peroxide concentration, and total boron concentration. Second‐order rate constants at 25 °C for the reaction of methyl 4‐nitrophenyl sulfide and H2O2, monoperoxoborate, HOOB(OH)3−, or diperoxoborate, (HOO)2B(OH)2−, are 8.29×10−5, 1.51×10−2 and 1.06×10−2 M−1 s−1, respectively. Peroxoboric acid, HOOB(OH)2, is unreactive. The Hammett ρ values for the reactions of a range of substituted phenyl methyl sulfides and hydrogen peroxide, monoperoxoborate or diperoxoborate are −1.50±0.1, −0.65±0.07 and −0.48 (two points only), respectively. The ρ values for the peroxoborates are of significantly lower magnitude than expected from their reactivity compared to other peroxides. Nevertheless the negative ρ values indicate positive charge development on the sulfur atom in the transition state consistent with nucleophilic attack by the organic sulfides on the peroxoborates as with the other peroxides. The kinetic parameters, including the lack of reactivity of peroxoboric acid, are discussed in terms of the differences in the transition state of reactions involving peroxoboron species with respect to those of other peroxides.
Nanotubes from Isomeric Dibenzoylmethane Molecules
Authors: Zhao Liyun , Yang Wensheng , Luo Yi , Zhai Tianyou , Zhang Guangjin , Yao Jiannian
Published: April 2005

Organic nanotubes of various diameters were fabricated from the isomeric molecule dibenzoylmethane (DBM) by using an immersing technique with ordered porous alumina membrane as the template. The ratio of the enol isomers of DBM increased as the diameters of the nanotubes decreased. In addition, although almost no fluorescence could be detected for the DBM monomer, a striking enhancement in the fluorescence emission intensity of the nanotubes was observed as the diameters decreased. This is due to the increased ratio of the enol isomers.
Mitogen‐activated protein kinase expression and activation does not differentiate benign from malignant mesothelial cells
Authors: Vintman Lina , Nielsen Søren , Berner Aasmund , Reich Reuven , Davidson Ben
Published: April 2005

BACKGROUND

In vitro studies of malignant mesothelioma (MM) cells have suggested activation of mitogen‐activated protein kinase (MAPK) in response to asbestos exposure. The objective of this study was to investigate protein expression (level) and phosphorylation status (activity) of the extracellular‐regulated kinase (ERK), the c‐Jun amino‐terminal kinase (JNK), and the high‐osmolarity glycerol response kinase (p38) in vivo through the analysis of fresh frozen reactive mesothelium (RM) and MM specimens.

METHODS

MAPK levels were analyzed in 36 fresh‐frozen MM specimens (32 effusions, 4 biopsies) and in 14 RM specimens (all effusions) using immunoblotting with antibodies detecting the total (pan‐) and activated (phospho‐) fraction (p‐) of ERK, JNK, and p38. Values for pan‐MAPK and p‐MAPK expression and the p‐MAPK/pan‐MAPK ratio in MM and RM specimens were compared. Results were corroborated using immunocytochemistry for p‐ERK, p‐JNK, and p‐38 in selected specimens.

RESULTS

Pan‐ERK, pan‐JNK, and pan‐p38 expression was found frequently in both MM specimens (35 of 36 specimens) and RM specimens (14 of 14 specimens) using immunoblotting, with comparable findings for activated p‐p38 (34 of 36 MM specimens, 13 of 14 RM specimens). Activation of p‐ERK (27 of 36 MM specimens, 10 of 14 RM specimens) and p‐JNK (25 of 36 MM specimens, 10 of 14 RM specimens) was less frequent. Pan‐ERK (P = 0.016), pan‐JNK (P = 0.004), pan‐p38 (P = 0.012), and p‐ERK (P = 0.02) expression levels were higher in MM specimens from female patients. Pan‐p38 expression levels also were higher in peritoneal MM specimens (P = 0.019). MM and RM showed similar MAPK expression, activation, and activation ratios (Mann–Whitney test; P > 0.05). Immunocytochemistry localized MAPK to MM and RM cells.

CONCLUSIONS

The current results provided the first evidence of in vivo activation of MAPK in clinical MM and RM. The similar values in these two cell types suggest that MAPK may not be involved in the transformation of benign to malignant mesothelium, thus bringing into question the validity of using MAPKs as molecular therapeutic targets in patients with MM. Cancer 2005. © 2005 American Cancer Society.
Toll‐like receptor signaling inhibits structural development of the distal fetal mouse lung
Authors: Prince Lawrence S. , Dieperink Heather I. , Okoh Victor O. , Fierro‐Perez German A. , Lallone Roger L.
Published: April 2005

We tested the hypothesis that innate immune signaling in utero could disrupt the structural development of the fetal lung, contributing to the pathogenesis of bronchopulmonary dysplasia. Injection of Escherichia coli lipopolysaccharide (LPS) into the amniotic fluid of E15 BALB/cJ mice increased the luminal volume density of fetal mouse lungs at embryonic day (E) 17 and E18. LPS also increased luminal volume and decreased distal lung branching in fetal mouse lung explants. This effect required NF‐κB activation and functional Toll‐Like Receptor 4. Airway branching may require fibronectin‐dependent epithelial–mesenchymal interactions, representing a potential target for innate immune signaling. Anti‐fibronectin antibodies and LPS both blocked distal lung branching. By immunofluorescence, fibronectin localized to the clefts between newly formed airways but was restricted to peripheral mesenchymal cells in LPS‐exposed explants. These data suggest that LPS may alter the expression pattern of mesenchymal fibronectin, potentially disrupting epithelial–mesenchymal interactions and inhibiting distal airway branching and alveolarization. This mechanism may link innate immune signaling with defects in structural development of the fetal lung. Developmental Dynamics 233:553–561, 2005. © 2005 Wiley‐Liss, Inc.
Expression analysis of jagged genes in zebrafish embryos
Authors: Zecchin Elisabetta , Conigliaro Alice , Tiso Natascia , Argenton Francesco , Bortolussi Marino
Published: April 2005

The interaction of transmembrane Delta and Jagged/Serrate ligands with Notch receptors on neighboring cells is critically involved in cell specification during development. In zebrafish, the early expression of delta but not of jagged genes has been investigated in some detail. We have analyzed the sequence and embryonic expression pattern of the three zebrafish genes jagged1a, jagged1b, and jagged2. These genes, whose transcripts are detectable by in situ hybridization from early somitogenesis, are widely and dynamically expressed in embryos. Coexpression is limited, however, to the notochord and lens (jagged1a and jagged1b) and to the otic vesicle and pronephros (jagged1b and jagged2). Conversely, jagged1a and jagged2, both widely expressed in the central nervous system, are not coexpressed. jagged2 is also detected in the epidermis, newly formed somites, pharyngeal pouches, and pancreatic exocrine anlage and jagged1b in otic placodes and cell clusters close to the pancreatic islet. The similarities of the expression patterns of jagged and delta genes in zebrafish suggest that the Jagged and Delta ligands are functionally redundant or required in specific combinations in many differentiation processes. Developmental Dynamics 233:638–645, 2005. © 2005 Wiley‐Liss, Inc.
Mechanics and function in heart morphogenesis
Authors: Bartman Thomas , Hove Jay
Published: April 2005

For years, biomechanical engineers have studied the physical forces involved in morphogenesis of the heart. In a parallel stream of research, molecular and developmental biologists have sought to identify the molecular pathways responsible for embryonic heart development. Recently, several studies have shown that these two avenues of research should be integrated to explain how genes expressed in the heart regulate early heart function and affect physical morphogenetic steps, as well as to conversely show how early heart function affects the expression of genes required for morphogenesis. This review combines the perspectives of biomechanical engineering and developmental biology to lay out an integrated view of the role of mechanical forces in heart development. Developmental Dynamics 233:373–381, 2005. © 2005 Wiley‐Liss, Inc.
Dynamic balance between activation and repression regulates pre‐mRNA alternative splicing during heart development
Authors: Ladd Andrea N. , Stenberg Myrna G. , Swanson Maurice S. , Cooper Thomas A.
Published: April 2005

Cardiac troponin T (cTNT) exon 5 splicing is developmentally regulated such that it is included in embryonic but not adult heart. CUG‐BP and ETR‐3‐like factor (CELF) proteins promote exon inclusion, whereas polypyrimidine tract binding protein (PTB) and muscleblind‐like (MBNL) proteins repress inclusion. In this study, we addressed what happens to these regulatory proteins during heart development to shift the regulatory balance of cTNT alternative splicing. Using dominant‐negative proteins, we found that both CELF and PTB activities are required for appropriate splicing in cardiomyocytes. Two CELF proteins, CUG‐BP and ETR‐3, are nuclear and cytoplasmic in embryonic heart but are down‐regulated in adult heart concomitant with loss of exon inclusion. In contrast, PTB and MBNL1 are expressed throughout heart development. The patterns of cTNT splicing and expression of its regulatory factors are conserved between mouse and chicken. Thus, alternative splicing is determined by a balance between positive and negative regulation, and modulation of expression levels of auxiliary splicing regulators may drive developmental splicing changes. ETR‐3 and CUG‐BP proteins are also down‐regulated in other tissues during development, suggesting that CELF proteins play a broad role in developmental splicing regulation. Developmental Dynamics, 2005. © 2005 Wiley‐Liss, Inc.
Boundary formation in the Drosophila wing: Functional dissection of Capricious and Tartan
Authors: Milán Marco , Pérez Lidia , Cohen Stephen M.
Published: April 2005

Cells in multicellular organisms often do not intermingle freely with each other. Differential cell affinities contribute to organizing cells into different tissues. Drosophila limbs and rhombomeres of the vertebrate hindbrain are subdivided into compartments. Cells in adjacent compartments do not mix. The wing primordium is subdivided into dorsal (D) and ventral (V) compartments by the activity of the LIM‐homeodomain protein Apterous in D cells. The leucine‐rich repeats transmembrane proteins Capricious and Tartan have been shown to contribute to formation of the affinity boundary between dorsal and ventral compartments. Here, we have carried out a structure–function analysis of Capricious and Tartan. We present evidence that both the extracellular and intracellular domains are required for the establishment of a DV affinity boundary. Our data suggest that the extracellular domains of Capricious and Tartan may work as ligands of an unknown D cell surface protein. Their intracellular domains may be required to transduce a signal necessary for the establishment of the DV boundary. Developmental Dynamics 233:804–810, 2005. © 2005 Wiley‐Liss, Inc.
Bone marrow mesenchymal progenitor cells inhibit lymphocyte proliferation by activation of the programmed death 1 pathway
Authors: Augello Andrea , Tasso Roberta , Negrini Simone Maria , Amateis Andrea , Indiveri Francesco , Cancedda Ranieri , Pennesi Giuseppina
Published: April 2005

Bone marrow mesenchymal progenitor cells (BMSC) are used for regenerating tissues of mesodermal origin, as well as tissues of different embryological derivation. Experimental evidence shows that BMSC are able to suppress the activation of the immune response by mechanisms that are still not completely understood. Thus far, in vitro studies carried using human or mouse cells indicate that autologous or allogeneic BMSC strongly suppress proliferation of T lymphocytes, triggered by cellular stimuli, nonspecific mitogenic stimuli, or antigenic peptides. Using cell proliferation and blocking assays, we demonstrated that BMSC inhibited the activation of murine splenocytes, T, and B lymphocytes. Direct contact of BMSC and target cells in a cognate fashion determined the inhibition of cell proliferation via engagement of the inhibitory molecule programmed death 1 (PD‐1) to its ligands PD‐L1 and PD‐L2, leading the target cells to modulate the expression of different cytokine receptors and transduction molecules for cytokine signaling. Soluble factors present on supernatants of BMSC cultures were effective in suppressing proliferation of B cells to a mitogenic stimulus. Taken together, these results highlight the complexity of the role of BMSC in regulating the immune response, asserting the possibility of their therapeutic application in transplantation and autoimmune diseases.
Chemokines synergize in the recruitment of circulating neutrophils into inflamed tissue
Authors: Struyf Sofie , Gouwy Mieke , Dillen Chris , Proost Paul , Opdenakker Ghislain , Van Damme Jo
Published: April 2005

The innate immune response against micro‐organisms is mediated by phagocytes, attracted by chemokines and other G protein‐coupled receptor (GPCR) ligands. Originally, we observed increased neutrophil migration by the interaction of inflammatory CXC chemokines such as IL‐8/CXCL8 and granulocyte chemotactic protein (GCP)‐2/CXCL6 with regakine‐1, a CC chemokine constitutively present in plasma. We here demonstrate statistically significant synergy between regakine‐1 and the neutrophil attractants C5a or IL‐8/CXCL8 in inducing neutrophil shape change and migration under agarose. In addition, regakine‐1 attracted human bone marrow granulocytes and enhanced their chemotactic response to IL‐8/CXCL8 in a dose‐dependent manner. Thus, plasma chemokines may regulate the number of circulating leukocytes under homeostatic conditions and may facilitate extra recruitment of bone marrow neutrophils during inflammation. Indeed, in vivo, regakine‐1 provoked a mild neutrophilia in rabbits upon intravenous injection. We also observed that the CC chemokines regakine‐1 and monocyte chemotactic protein‐3/CCL7 as well as the CXC chemokine stromal cell‐derived factor‐1α/CXCL12 co‐operated with murine GCP‐2 after intraperitoneal co‐administration to increase neutrophil influx in mice. These data demonstrate that inducible and constitutive GPCR ligands synergize to enhance inflammation and facilitate a more effective immune response.
Split peripheral tolerance: CD40 ligation blocks tolerance induction for CD8 T cells but not for CD4 T cells in response to intestinal antigens
Authors: Chung Yeonseok , Ko Sung‐Youl , Ko Hyun‐Jeong , Kang Chang‐Yuil
Published: April 2005

The role of antigen‐presenting cells in the balance between immunity and tolerance to intestinal antigens remains poorly understood. In this study, we examined whether CD40 ligation affects the induction of CD4 and CD8 T cell tolerance in response to intestinal antigens. We show that an agonistic anti‐CD40 mAb treatment did not block the induction of OVA‐specific CD4 T cell tolerance, whereas this approach enabled strong priming of OVA‐specific cytotoxic T cells (CTL), preventing CTL tolerance to intestinal antigen. Such CTL priming was independent of CD4 T cell help but required B7 costimulation. Co‐administration of anti‐CD40 mAb increased the synthesis of IL‐2 and the expression of CD25 by CD8 T cells, but neither IL‐2 production nor CD25 expression by CD4 T cells was enhanced by anti‐CD40 mAb. However, neutralization of TGF‐β together with addition of agonistic anti‐CD40 mAb was able to reverse CD4 T cell tolerance. These findings suggest that the induction of tolerance versus immunity against intestinal antigens is determined by the status of the antigen‐presenting cells and that signals via CD40 differently regulate the outcome of CD4 and CD8 T cells in vivo.
Remediation of sites contaminated by oil refinery operations
Authors: Khaitan S. , Kalainesan S. , Erickson L.E. , Kulakow P. , Martin S. , Karthikeyan R. , Hutchinson S.L.L. , Davis L.C. , Illangasekare T.H. , Ng'oma Crispin
Published: April 2005

The oil industry contributes to contamination of groundwater and aquifers beneath refineries and oil terminals. The successful remediation of a contaminated site requires understanding both the hydrogeology and the nature and extent of contamination. The physical–chemical and biological mechanisms that govern contaminant release, transport and fate in soils, sediments, and associated fluid phases must be understood and quantified. In addition, understanding the flow and entrapment of nonaqueous phase liquids (NAPLs) including lighter‐than‐water nonaqueous phase liquids (LNAPLs) in contaminated aquifers is important for the effective design of the recovery and remediation schemes. Current remedial technologies and risk assessment techniques to remediate former oil refinery sites contaminated by NAPLs are described in this paper. Emphasis is given to the most promising remediation techniques such as pump‐and‐treat, on‐site bioremediation, phytoremediation, in situ soil washing, and thermal‐based technologies, such as steam‐enhanced extraction. Some enhancements to pump‐and‐treat techniques such as solvent flushing, polymer enhanced flushing, and air stripping are also discussed. Finally, important risk‐based cleanup criteria associated with contaminated soil at refineries are presented. © 2005 American Institute of Chemical Engineers Environ Prog, 2005
Proton affinity ladder for uridine and analogs: influence of the hydroxyl group on the sugar ring conformation
Authors: Mezzache S. , Alves S. , Pepe C. , Quelquejeu M. , Fournier F. , Valery J.‐M. , Tabet J.‐C.
Published: April 2005

A ladder of relative proton affinities (PA) for a series of modified uridines (e.g. araU, ddU, 5BrU, 5BrdU and 5IU) was established from competitive dissociations of proton‐bound heterodimers using Cooks and co‐workers' kinetic method. The studied heterodimers are constituted of a modified nucleoside and either an amino acid or a nucleoside with known PA value. These non‐covalent heterodimers were prepared under electrospray conditions to be selected and dissociated into the ion‐trap analyzer. These results allowed our PA ladder of uridine and deoxyuridine analogs substituted at the C‐5 position in the uracil ring to be extended. From this scale, it was showed that the substitution of hydrogen atom at the C‐2′ position in the sugar ring by a hydroxyl group involves a decrease of about 7 kJ mol−1. The experimental values for U, 5MeU, dU, 5MedU, ddU and araU are consistent with those obtained by DFT calculations (B3P86/6–31+G*//B3LYP/6–31G*). Several neutral and protonated conformations of these compounds were considered, in particular the ring conformation of furanose and the orientation of the base with respect to the sugar ring. These calculated results showed the influence of sugar substituent on the conformation of the neutral form of theses nucleosides. However, the most stable protonated structure is the same for all the studied nucleosides except for araU, where the position of the anti 2′‐OH group imposes a specific conformation. Copyright © 2005 John Wiley & Sons, Ltd.
Rheology and Drug Release Properties of Bioresorbable Hydrogels Prepared from Polylactide/Poly(ethylene glycol) Block Copolymers
Authors: Li Suming , El Ghzaoui Abdelslam , Dewinck Emilie
Published: April 2005

Ring‐opening polymerization of L(D)‐lactide was realized in the presence of poly(ethylene glycol) (PEG), yielding PLLA/PEG and PDLA/PEG block copolymers. Bioresorbable hydrogels were prepared from aqueous solutions containing both copolymers due to interactions and stereocomplexation between PLLA and PDLA blocks. The rheological properties of the hydrogels were investigated under various conditions by changing copolymer concentration, temperature, time and frequency. The hydrogels constitute a dynamic and evolutive system because of continuous formation/destruction of crosslinks and degradation. Drug release studies were performed on hydrogel systems containing bovine serum albumin (BSA). The release profiles appear almost constant with little burst effect. The release rate depends not only on gelation conditions such as time and temperature, but also on factors such as drug load, as well as molar mass and concentration of the copolymers.
Structural Evolution Process in Solvent‐Induced Crystallization Phenomenon of Syndiotactic Polystyrene
Authors: Tashiro Kohji
Published: April 2005

Structural change has been traced in the solvent‐induced crystallization phenomenon of syndiotactic polystyrene through the time‐resolved measurements of infrared and Raman spectra and X‐ray diffraction. Immediately after the solvent is supplied to the glassy sample, the random coils start a micro‐Brownian motion and locally change to short regular helical segments after some induction time. These segments grow longer and gather together to form the crystal lattice. This crystallization occurs even at room temperature far below the original glass transition temperature (Tg = ca. 100°C), because Tg is shifted to ca. −90°C (in the case of chloroform) due to the plasticizing effect, as revealed by the temperature‐dependent infrared spectral measurement and the molecular dynamics calculation. The thus‐created sPS‐solvent complex was found to show a fast and reversible solvent exchange phenomenon between the originally‐existing solvent (toluene, for example) and the newly‐supplied different type of solvent (chloroform, for example). The time‐dependent measurement of wide‐angle and small‐angle X‐ray scatterings using a synchrotron radiation source revealed that the solvent exchange occurs with keeping both the columnar structure of the crystal and the stacked lamellar structure, and that the solvent exchange rate is in the order of chloroform > benzene > toluene, reflecting the difference in diffusion rate of solvent molecules and polymer‐solvent interaction.
Preparation and Characterization of Interpenetrating Polymer Hydrogels Based on Poly(acrylic acid) and Poly(vinyl alcohol)
Authors: Hernández Rebeca , López Daniel , Pérez Ernesto , Mijangos Carmen
Published: April 2005

Interpenetrating polymer hydrogels (IPHs) of Poly (vinyl alcohol) (PVA) and Poly (acrylic acid) (PAAc) have been prepared by a sequential method: crosslinked PAAc chains were formed in aqueous solution by crosslinking copolymerization of acrylic acid and N, N′‐methylenebisacrylamide in the presence of PVA. The application of freezing‐thawing cycles (F‐T cycles) leads to the formation of a PVA hydrogel within the synthesized PAAc hydrogel. The swelling and the viscoelastic properties of the prepared IPHs were evaluated on the basis of the structural features obtained from solid state 13C‐NMR spectroscopy.
Effect of Solubility Parameter of Polymer‐Solvent Pair on Turbulent Drag Reduction
Authors: Kim Chul Am , Choi Hyoung Jin , Sung Jun Hee , Lee Hyung Min , Jhon Myung S.
Published: April 2005

Polymer‐induced turbulent drag reduction by adding a minute amount of high‐molecular weight polyisobutylene (PIB) into two different organic solvents of n‐heptane and xylene was examined using a rotating disk system. The dependence of drag reduction (DR) efficiency on various factors such as polymer molecular weight, polymer concentration (C), and solvent quality was examined. Based on the linear relationship between C and C/DR for different molecular weights of PIB, a universal curve was able to characterize a particular polymer/solvent family, independent of the molecular weight of polymer.
Thermoreversible Gelation of Poly(vinylidene fluoride) – Camphor System
Authors: Dasgupta D. , Manna Swarup , Malik Sudip , Rochas Cyrille , Guenet Jean Michel , Nandi A.K.
Published: April 2005

Poly (vinylidene fluoride) (PVF2) produces thermoreversible gel in camphor when quenched to 25°C from the melt under sealed condition. The SEM micrograph of dried PVF2/camphor gel (W= 0.25) indicates presence of fibrillar network structure and the gels at different composition shows reversible first order phase transition. The phase diagram of the gel suggest the formation of a polymer‐ solvent complex. The melting enthalpy gives a stoichiometric composition of the complex at W= 0.25. This corresponds to a molar ratio of PVF2 monomer/camphor ≈ 4/5. Temperature‐dependent synchroton experiments further support the conclusions derived from the phase diagram.
Simulation of Electrical and Thermal Behavior of Poly(propylene) / Carbon Filler Conductive Polymer Composites
Authors: Feller Jean François , Glouannec Patrick , Salagnac Patrick , Droval Guillaume , Chauvelon Philippe
Published: April 2005

PP‐carbon CPC show interesting thermo‐electrical properties, smooth resistivity increase with temperature up to 150°C and consequently high power dissipation on a wide temperature range. The addition of short carbon fibers to PP already formulated with carbon black increases sharply the electrical conductivity of the CPC but does not have much influence on thermal conductivity as it could have been expected from the favorable aspect ratio of the fibers. The simulations of the thermo‐electrical behavior of the CPC under tension put into evidence a temperature gradient at high heat flux due to the low thermal conductivity, which may damage the material itself.
Stabilisation Effect of Calcium Ions on Polymer Network in Hydrogels Derived from a Lyotropic Phase of Hydroxypropylcellulose
Authors: Joachimiak Aleksandra , Okrasa Lidia , Halamus Tomasz , Wojciechowski Piotr
Published: April 2005

The process of crosslinking of the hydrogel, derived from lyotropic liquid crystalline (LLC) phases of hydroxypropylcellulose/acrylic acid‐water, by calcium ions was studied by means of Raman and dielectric spectroscopy. Formation of salt by poly(acrylic acid) and calcium ions, resulting in hydrogel crosslinking, induces differences in Raman spectra of the hydrogel before and after the crosslinking. The crosslinking results in significant increase in the activation energy of β‐relaxation of poly(acrylic acid). This is a direct consequence of restriction in motions of carboxylic groups of poly(acrylic acid) due to calcium salt formation. Thus, the crosslinking improves polymer network stability in the hydrogel in the swollen state.
Do pharmacists' opinions affect their decision to dispense or recommend a visit to a doctor?
Authors: Caamaño‐Isorna Francisco , Montes Agustin , Takkouche Bahi , Gestal‐Otero J. J.
Published: April 2005

Purpose

To assess the relation between the pharmacists' opinions and the decision to dispense drugs without medical prescription and to recommend a visit to a doctor.

Methods

We carried out a cohort study on a sample of 166 pharmacists in North‐West Spain. Pharmacists' opinions on prescription practice of the doctors, on pharmacists' qualification to dispense drugs without medical prescription, on their responsibility about dispensed drugs, on clients' qualification for self‐medication, and pharmacists' perception of their work were collected through a personal interview. Dispensing and the recommendation to the patient to visit their doctor were measure in the follow‐up. We constructed logistic regression models.

Results

The response rate to the first questionnaire was 98.8% and the participation rate in the follow‐up was 60%. Pharmacists who considered that doctors prescribed excessively were less likely to dispense without medical prescription (OR = 0.48) and to send the client to the doctor more often (OR = 2.33). On the other hand, those who considered themselves to be capable to dispense without prescription do so frequently (OR = 1.24). A major appreciation of the pharmacist as a health educator was associated with a higher dispensing (OR = 3.81). Pharmacists who considered that customers' qualification for self‐medication was good recommended, more frequently visiting a doctor (OR = 1.58).

Conclusions

Our results show that the pharmacists' opinions are associated with their practice of counseling. Therefore, any program designed with the purpose of changing dispensing habits of the pharmacists should identify and take into account their opinions. Copyright © 2005 John Wiley & Sons, Ltd.
Chylothorax in Henoch‐Schonlein purpura: A case report and review of the literature
Authors: Cogar Bryan D. , Groshong Ted D. , Turpin Brian K. , Guajardo Jesus R.
Published: April 2005

Henoch‐Schonlein purpura (HSP) is the most common acute vasculitis in the pediatric population, with an incidence of 10–14 per 100,000. The classic presentation of this disorder includes erythematous papules followed by palpable purpura in the lower extremities, trunk, and face, arthralgia or arthritis, abdominal pain, gastrointestinal bleeding, and nephritis. While renal abnormalities in HSP are common, the classic pulmonary manifestations, such as hemorrhage and pneumonitis, are thought to be infrequent. Subclinical pulmonary manifestations, including diffusion defects and radiographic anomalies, seem to be quite frequent in patients with HSP but are not commonly reported. Other respiratory manifestations include pleural effusion and chylothorax, but these are rarely mentioned in the literature. Chylothorax was only reported once in an adult patient with HSP in whom the mechanism of formation was demonstrated to be secondary to transdiaphragmatic passage of chylous fluid from the peritoneal cavity. Here we describe an 8‐year‐old girl with HSP, nephrotic syndrome, and chylothorax, and we report the results of a review of the literature regarding respiratory complications in HSP. The present case is the first pediatric patient reported with HSP and chylothorax. The therapeutic measures utilized were effective in resolving her edema, ascites, and chylothorax, and we advocate the use of these measures as first‐line therapy in future patients with similar complications from HSP. © 2005 Wiley‐Liss, Inc.
How much do Pseudomonas biofilms contribute to symptoms of pulmonary exacerbation in cystic fibrosis?
Authors: VanDevanter Donald R. , Van Dalfsen Jill M.
Published: April 2005

Recent studies suggest that chronic Pseudomonas aeruginosa lung infections in cystic fibrosis (CF) involve anaerobic biofilms, and that these biofilms are the reason chronic infections are rarely eradicated by antibiotic therapy, regardless of the in vitro susceptibility of infecting bacteria. These observations led to the development of an in vitro method for testing antibiotic susceptibility of CF clinical isolates in biofilms (Moskowitz et al., J Clin Microbiol 2004;42:1915–1922) and unearthed an apparent paradox. Antibiotics that remain cornerstones of clinical management of CF pulmonary exacerbations (e.g., beta‐lactam antibiotics) appear to have little to no activity at clinically achievable concentrations when tested in vitro against clinical P. aeruginosa isolates growing in biofilms. The proven clinical efficacy of beta‐lactam antibiotics in treating exacerbations, and the selection for beta‐lactam resistance in vivo, suggest that planktonic bacteria play a significant role in pulmonary exacerbations of CF. A model of infection architecture is proposed in which biofilm and planktonic compartments each play a role in infection persistence and pulmonary exacerbation, respectively. Infection architecture may partially account for the observed lack of correlation between in vitro antibiotic susceptibility testing and clinical response to antibiotic therapy. © 2005 Wiley‐Liss, Inc.
Atrial natriuretic peptide in children with pneumonia
Authors: Haviv Michal , Haver Eitan , Lichtstein David , Hurvitz Haggit , Klar Aharon
Published: April 2005

Atrial natriuretic peptide (ANP) has known natriuretic, diuretic, and vasodilatatory effects. It is synthesized and stored in the atrial cells. Stretching of the atrial muscle fibers during an increase in venous return sets a response of ANP release into the blood stream. High levels of ANP were measured in a number of lung diseases. Pneumonia in children is frequently accompanied by the hyponatremia of the syndrome of inappropriate antidiuretic hormone (ADH) secretion (SIADH). High levels of ANP were found among patients with SIADH. Our objective was to determine if ANP plasma levels are altered in children with pneumonia, and to evaluate a possible correlation between severity of pneumonia and ANP levels. Blood samples from 28 children diagnosed with pneumonia were collected. Plasma ANP levels were determined by radioimmunoassay and compared to levels in 25 children without pneumonia. ANP levels in the pneumonia group (mean ± SD, 16.02 ± 11.69 pg/ml) increased significantly (P < 0.01) compared to levels in the control group (mean ± SD, 7.44 ± 9.29 pg/ml). Children in the pneumonia group also exhibited low levels of plasma sodium (mean ± SD, 134.88 ± 2.5 mmol/l) compared to levels in children without pneumonia (mean ± SD, 139.77 ± 4.15 mmol/l) (P < 0.01). There was no correlation between ANP plasma levels and severity of pneumonia. In conclusion, ANP levels in children with pneumonia, as in other lung diseases, are increased. High ANP levels may play a role in maintaining water and electrolyte equilibrium during a state of inappropriate ADH secretion accompanying pneumonia. © 2005 Wiley‐Liss, Inc.
Frequency–voltage cooperative CPU power control: A design rule and its application by feedback prediction
Authors: Toyama Keisuke , Misaka Satoshi , Aisaka Kazuo , Aritsuka Toshiyuki , Uchiyama Kunio , Ishibashi Koichiro , Kawaguchi Hiroshi , Sakurai Takayasu
Published: April 2005

Frequency–voltage cooperative power control (FVC) is a powerful method to reduce the CPU power consumption of a program during execution, because it utilizes the information on the software workload dynamically. In this paper, we first show through a mathematical analysis the design rule to determine the necessary frequencies and its effect. Then we show experimental results of implementing an FVC with a feedback algorithm on MPEG‐4 video and MP3 audio decoders with two sets of frequency and voltage. The FVC gave a 72% reduction in CPU power consumption during execution. In addition, we show a “Cool‐Start” method that begins the FVC at a lower frequency and improves the power reduction effect. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 36(6): 39–48, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20263
Estimation of anatomical landmark positions from model of 3‐dimensional foot by the FFD method
Authors: Yahara Hiroki , Higuma Naoki , Fukui Yukio , Nishihara Seiichi , Mochimaru Masaaki , Kouchi Makiko
Published: April 2005

This paper proposes a method of estimation of the anatomical landmarks that are needed in product design from point clouds of body shape measured by a three‐dimensional scanner. The algorithm is described briefly. First, the standard model is defined as the average shape with anatomical landmarks calculated from multiple body data samples with given anatomical landmarks. Then, the matching transformation is applied to the standard model so that it fits the body shape data of the target model. The anatomical landmarks of the target body shape are estimated from the deformed standard model. Free‐form deformation (FFD) is used as the matching transformation, in which the deformation control lattice coordinates are determined from an estimation formula derived by multiple regression analysis of the multiple body data sample. This method is applied to a foot model for shoe design. The effectiveness of the proposed method is verified by an experimental evaluation. © 2005 Wiley Periodicals, Inc. Syst Comp Jpn, 36(6): 26–38, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20270
Developing WWW‐based highly interactive and collaborative applications using software components
Authors: Anido Luis , Llamas Martin , Fernández Manuel J.
Published: April 2005

This paper describes a layered framework to support WWW‐based interactive and collaborative applications. Using some commercial‐off‐the‐shelf (COTS) software, three basic services are built: virtual rooms, virtual file systems, and database connectivity. These services are used at a second layer, which actually provides the functionality of the framework. The components that have been described at this level can be embedded in WWW‐based business applications in an easy and direct way. Therefore, programmers can focus on the particular logic of their applications, avoiding most of the issues related to collaboration, networking, and access control. In order to test the developed framework a WWW‐based educational application has been implemented. This tele‐education system, with innovative features in the field of WWW‐based practical training, is the second contribution presented by the authors. Copyright © 2001 John Wiley & Sons, Ltd.
Mapping seabed habitats in the Firth of Lorn off the west coast of Scotland: evaluation and comparison of habitat maps produced using the acoustic ground-discrimination system, RoxAnn, and sidescan sonar
Authors: Brown Craig J. , Mitchell Annika , Limpenny David S. , Robertson Mike R. , Service Matthew , Golding Neil
Published: April 2005

In September 2003 a national workshop took place in the United Kingdom with the aim of assessing the accuracy of the acoustic ground-discrimination system (AGDS), RoxAnn™, as a tool for mapping seabed habitats in Special Areas of Conservation (SACs). A heterogeneous area of seabed, approximately 1 km2 in size, was selected for the study. The area was first surveyed using a sidescan-sonar system and a mosaic of the output was produced covering 100% of the survey area. Interpretation of the mosaic identified three acoustically distinct seabed types, the spatial distributions of which were mapped. Four RoxAnn data sets were then collected over the same area of seabed applying different survey parameters (e.g. different survey grids, track spacing, survey vessels, survey speeds, and RoxAnn systems). Extensive ground-truthing was carried out involving 26 drop-down video stations, and from these data six benthic classes (seabed habitats) were identified. Following interpolation of the RoxAnn track-point data to produce full spatial-coverage data, these six-seabed habitat categories were used to conduct supervised classification of the RoxAnn data to produce full-coverage habitat maps of the area for each of the four RoxAnn data sets. Comparisons were then made between the four RoxAnn maps and the sidescan-sonar interpreted map. The accuracy of each map was assessed and the application of this mapping approach for mapping seabed habitats in SACs is discussed.