bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparative study of multi‐class support vector machines in the unifying framework of large margin classifiers
Authors: Guermeur Yann , Elisseeff André , Zelus Dominique
Published: March 2005

Vapnik's statistical learning theory has mainly been developed for two types of problems: pattern recognition (computation of dichotomies) and regression (estimation of real‐valued functions). Only in recent years has multi‐class discriminant analysis been studied independently. Extending several standard results, among which a famous theorem by Bartlett, we have derived distribution‐free uniform strong laws of large numbers devoted to multi‐class large margin discriminant models. The capacity measure appearing in the confidence interval, a covering number, has been bounded from above in terms of a new generalized VC dimension. In this paper, the aforementioned theorems are applied to the architecture shared by all the multi‐class SVMs proposed so far, which provides us with a simple theoretical framework to study them, compare their performance and design new machines. Copyright © 2005 John Wiley & Sons, Ltd.
A tutorial on ν‐support vector machines
Authors: Chen Pai‐Hsuen , Lin Chih‐Jen , Schölkopf Bernhard
Published: March 2005

We briefly describe the main ideas of statistical learning theory, support vector machines (SVMs), and kernel feature spaces. We place particular emphasis on a description of the so‐called ν‐SVM, including details of the algorithm and its implementation, theoretical results, and practical applications. Copyright © 2005 John Wiley & Sons, Ltd.
Use of cutting balloon for palliative treatment in tetralogy of Fallot
Authors: Carlson Karina M. , Neish Steven R. , Justino Henri , Leonard Glenn T. , Mullins Charles E. , Grifka Ronald G.
Published: March 2005

In tetralogy of Fallot, severe cyanosis due to insufficient pulmonary blood flow necessitates early intervention. The Cutting Balloon, developed for percutaneous coronary angioplasty, was used successfully for transcatheter incision and dilation of infundibular and valvar pulmonary stenosis in four patients with tetralogy of Fallot. Catheter Cardiovasc Interv 2005;64:507–512. © 2005 Wiley‐Liss, Inc.
Multiple sensitive periods in human visual development: Evidence from visually deprived children
Authors: Lewis Terri L. , Maurer Daphne
Published: March 2005

Psychophysical studies of children deprived of early visual experience by dense cataracts indicate that there are multiple sensitive periods during which experience can influence visual development. We note three sensitive periods within acuity, each with different developmental time courses: the period of visually‐driven normal development, the sensitive period for damage, and the sensitive period for recovery. Moreover, there are different sensitive periods for different aspects of vision. Relative to the period of visually driven normal development, the sensitive period for damage is surprisingly long for acuity, peripheral vision, and asymmetry of optokinetic nystagmus, but surprisingly short for global motion. A comparison of results from unilaterally versus bilaterally deprived children provides insights into the complex nature of interactions between the eyes during normal visual development. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46: 163–183, 2005.
Critical period: A history of the transition from questions of when, to what, to how
Authors: Michel George F. , Tyler Amber N.
Published: March 2005

Although age appears to be the defining characteristic of the concept of critical period, central to its investigation is the recognition that there are specific events which must occur in a particular order for the typical development of certain characteristics to occur. A brief history of some research on critical periods reveals that our questions have shifted from those of: is there a critical period and, if so, when does it occur; to questions of what contributes to the criticality of the period; and finally to how is criticality controlled during development. Abandoning age as a defining component of development has permitted the discovery of exactly how previous and current events construct subsequent events in the process of development. The shifts in questions about critical periods mark an increasing sophistication in understanding how development can be controlled. © 2005 Wiley Periodicals, Inc. Dev Psychobiol 46: 156–162, 2005.
Investigations into the Reactivity of Organoelement Gallium and Indium Subhalides – Syntheses of Digallium and Diindium Acetylacetonates
Authors: Uhl Werner , El‐Hamdan Abdelhakim , Lawerenz Andreas
Published: March 2005

The organoelement subhalides R2Ga2I2 (1) and [R2In2Cl2]2 (2) [R = C(SiMe3)3] react with silver acetylacetonate Ag(acac) (acac = [OC(CH3)]2CH) and lithium acetylacetonate Li(acac), respectively, to yield the di(acetylacetonato)dielement compounds R2E2(acac)2 (3: E = Ga; 4: E = In). Both products possess E–E single bonds with relatively long E–E distances of 251.1 (Ga–Ga) and 278.0 pm (In–In). The gallium or indium atoms are terminally coordinated by an alkyl and a bidentate acetylacetonato group. Similar reactions of the subhalides 1 and [R2In2Br2]2 with lithium diphenyltriazenide LiN3(C6H5)2 did not result in the formation of dielement compounds analogous with 3 and 4 but in the cleavage of the E–E bonds with formation of element(III) compounds of the type R–E(X)[N3(C6H5)2] (E = Ga, In; X = Br, I). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Titanium Complexes of Chelating, Dianionic O,S,O‐Bisphenolato Ligands: Syntheses, Characterisation, and Catalytic Activity
Authors: Janas Zofia , Jerzykiewicz Lucjan B. , Przybylak Katarzyna , Sobota Piotr , Szczegot Krzysztof , Wiśniewska Dorota
Published: March 2005

Titanium complexes based on 2,2′‐thiobis[4‐(1,1,3,3‐tetramethylbutyl)phenolato] (tbop) are prepared by reaction of TiCl4 or Ti(NMe2)4 with the parent biphenol. Three new complexes are reported: [Ti2(μ‐tbop‐κ3O,S,O)(μ‐tbop‐κ2O,O)‐(tbop‐κ3O,S,O)Cl2] (1)·2 CH3CN, [Ti2(μ‐tbop‐κ3O,S,O)2Cl4] (2) and [Ti(tbop‐κ3O,S,O)2] (3). Substitution of the chlorides in 1 and 2 by 2,6‐diisopropylphenolato and imido (NtBu) ligands generates the new compounds [Ti2(μ‐tbop‐κ3O,S,O)2‐Cl2(dipp)2] (4)·Et2O and [Ti2(μ‐tbop‐κ3O,S,O)2(NtBu)2‐(NH2tBu)2] (5), respectively. Treatment of 5 with crude Me3‐SiCl, containing Me3SiOH, produces [Ti(tbop‐κ3O,S,O)Cl(OSiMe3)(NH2tBu)] (6). Reaction of 2 with an excess of NHiPr2 provides a mixture of compounds: ionic [NH2iPr2][Ti(tbop‐κ3O,S,O)Cl3] (7)·CH2Cl2 and molecular [Ti2(μ‐tbop‐κ3O,S,O)2‐Cl2(NiPr2)2] (8). The structures of 1–8 were confirmed by NMR spectroscopy; complexes 1, 5, 6 and 7 were further investigated by X‐ray crystallography. Compounds 1, 2, 4 and 5, when supported on MgCl2 and activated with alkylaluminiums, effectively polymerise ethene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
In vitro Relaxometric and Luminescence Characterization of P792 (Gadomelitol, Vistarem®), an Efficient and Rapid Clearance Blood Pool MRI Contrast Agent
Authors: Vander Elst Luce , Raynal Isabelle , Port Marc , Tisnès Pierre , Muller Robert N.
Published: March 2005

P792 (Gadomelitol, Vistarem®), a hydrophilic high molecular weight (MW = 6473 g/mol) derivative of DOTA‐Gd is a rapid clearance blood pool agent (RCBPA) characterized by high proton relaxivities r1 and r2 at 310 K in the current range of clinical imaging magnetic fields. Luminescence data of the EuIII complex, as expected for this type of DOTA derivative, agree with the presence of one water molecule in the first coordination sphere of the lanthanide ion. The stability of the water proton longitudinal relaxation rate in the presence of zinc(II) and phosphate ions showed that the transmetallation by ZnII ions is negligible. The temperature dependence of the water oxygen‐17 transverse relaxation rate gave a τM smaller than 100 ns at 310 K. No significant increase of longitudinal or transverse relaxation rates in serum or HSA solution was noticed, precluding association with high molecular weight blood components. The proton Nuclear Magnetic Relaxation Dispersion (NMRD) profile of the water solution showed a maximum of longitudinal relaxivity between 20 and 40 MHz (r1 ≈ 40 s–1 mM–1 at 310 K). Fitting of the proton NMRD curve by the classical outersphere and innersphere models, including or not additional second sphere water molecules, gave a rotational correlation time of approximately 2 to 3 ns and a large value of the electronic relaxation time at low field (τSO ≈ 500 ps). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Low‐Valent Titanium–Pentafulvene Complexes — Formation of Dinuclear Titanium–Nitrogen Complexes
Authors: Scherer Axel , Kollak Kay , Lützen Arne , Friedemann Marion , Haase Detlev , Saak Wolfgang , Beckhaus Rüdiger
Published: March 2005

Sodium amalgam reduction of [(η5‐C5Me5)TiCl3] (1) in the presence of the pentafulvenes {C5H4=CR2, R: p‐tol (2), p‐FPh (3), CR2: adamantyl (4)} under nitrogen smoothly produces dark green or dark blue dinuclear low‐valent titanium complexes [{(η5‐C5Me5)Ti(η6‐C5H4=CR2)}2(μ2,η1,η1‐N2)] {R: p‐tol (6), p‐FPh (7), CR2: adamantyl (8)}, characterized by a bridging end‐on coordinated dinitrogen ligand, in high yield. In the same way, the nitrogen‐free, low‐coordinated complex [(η5‐C5Me5)Ti(η6‐C9H6=C(p‐tol)2)] (10) is obtained by using the more sterically demanding benzofulvene C9H6=C(p‐tol)2 (5) instead of 2–4. The solid‐state structures of the dinitrogen compounds reveal weakly activated end‐on bound N2 ligands with identical N–N distances of 1.160(3) Å (6) and 1.160(5) Å (8). The dinitrogen complexes 6, 7 and 8 show diamagnetic behaviour, which allowed a complete NMR spectroscopic characterization. So a correlation between the situation in solution, measured by NMR, and in the solid state (X‐ray diffraction) becomes possible and shows a congruent picture. A broad range of reactions can be imagined concerning the easily replaceable dinitrogen ligand as well as the known reactivity of fulvene ligands in complexes of early transition metals. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Low‐Valent Titanium−Pentafulvene Complexes − Formation of Dinuclear Titanium−Nitrogen Complexes (Eur. J. Inorg. Chem. 6/2005)
Authors: Scherer Axel , Kollak Kay , Lützen Arne , Friedemann Marion , Haase Detlev , Saak Wolfgang , Beckhaus Rüdiger
Published: March 2005

The cover picture shows a high‐yield, one‐step synthesis of end‐on bridged dinuclear titanium−dinitrogen complexes using Cp*TiCl3, N2 and pentafulvenes under reductive conditions. The Cp* as well as the fulvene ligands are arranged in a stereoregular manner along the Ti−N≡N−Ti axis, both in the solid state as well as in solution, as proved by extensive NMR measurements. Details are discussed in the article by R. Beckhaus et al. on p. 1003 ff. In a similar way a nitrogen‐free, low‐coordinated titanium complex is obtained by using sterically demanding benzofulvenes. We thank the Fonds der Chemischen Industrie for a kindly granted scholarship (A. S.).
Image‐based view rendering in endoscopy
Authors: Koppel Dan , Wang Yuan‐Fang , Lee Hua
Published: March 2005

Video endoscopy, a modality of minimally invasive surgery, has proven to be significantly less invasive to the patient. However, by relying on a video interface to observe the surgical scene, several nonintuitive effects need to be contended with. One of these is the reduction or removal of the discrepancy in view position and orientation between the surgeon and the endoscope. Eliminating artifacts in the visual feedback is important for the improvement of the effectiveness of the surgical procedures. This article presents a novel rendering technique to produce the scene from a “surgeon‐centric” viewpoint to create greater transparency for optimizing the visual precision of the endoscopic procedures. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol 14, 181–185, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ima.20022
Phenolic wastewater treatment in a three‐phase fluidised bed bioreactor containing low density particles
Authors: Sokół Włodzimierz , Korpal Wojciech
Published: March 2005

The treatment of phenolic wastewater was investigated in a gas–liquid–solid fluidised bed bioreactor containing polypropylene particles of density 910 kg m−3. Measurements of chemical oxygen demand (COD) versus residence time (t) were performed for various ratios of settled bed volume to bioreactor volume (Vb/VR) and air velocities (u) to determine the values of (Vb/VR) and u for which the largest reduction in COD occurred. Optimal operation, corresponding to the largest COD removal, was attained when the bioreactor was controlled at the ratio (Vb/VR) = 0.55 and an air velocity u = 0.036 m s−1. Under these conditions, the value of COD was practically at steady state for times greater than 50 h. At this steady state, only about 50% COD removal was achieved in the treatment of a ‘raw’ wastewater (no mineral salts added), whereas in the operation with wastewater enriched in nutrient salts approximately 90% COD removal was attained. The following amount of mineral salts (mg dm−3): (NH4)2SO4—500; KH2PO4—200; MgCl2—30; NaCl—30; CaCl2—20; and FeCl3—7, when added to wastewater before treatment, was sufficient for biomass growth. The application of low density particles (used as biomass support) in a bioreactor allowed the control of biomass loading in the apparatus. In the cultures conducted after change in (Vb/VR) at a set u, the steady state mass of cells grown on the particles was achieved after approximately 6 days of operation. With change in u at a set (Vb/VR), the new steady state biomass loading occurred after culturing for about 2 days. Phenolic wastewater was successfully treated in a bioreactor. In the operation conducted in a bioreactor optimally controlled at (Vb/VR) = 0.55, u = 0.036 m s−1 and t = 50 h, conversions greater than 99% were achieved for all phenolic constituents of the wastewater. Conversions of about 90% were attained for other hydrocarbons. Copyright © 2005 Society of Chemical Industry
Heavy cycles passing through some specified vertices in weighted graphs
Authors: Fujisawa Jun , Yoshimoto Kiyoshi , Zhang Shenggui
Published: March 2005

A weighted graph is one in which every edge e is assigned a nonnegative number, called the weight of e. The sum of the weights of the edges incident with a vertex υ is called the weighted degree of υ. The weight of a cycle is defined as the sum of the weights of its edges. In this paper, we prove that: (1) if G is a 2‐connected weighted graph such that the minimum weighted degree of G is at least d, then for every given vertices x and y, either G contains a cycle of weight at least 2d passing through both of x and y or every heaviest cycle in G is a hamiltonian cycle, and (2) if G is a 2‐connected weighted graph such that the weighted degree sum of every pair of nonadjacent vertices is at least s, then for every vertex y, G contains either a cycle of weight at least s passing through y or a hamiltonian cycle. AMS classification: 05C45 05C38 05C35. © 2005 Wiley Periodicals, Inc. J Graph Theory
Chronic obstructive pulmonary disease is associated with enhanced bronchial expression of FGF‐1, FGF‐2, and FGFR‐1
Authors: Kranenburg Andor R , Willems‐Widyastuti Anna , Mooi Wolter J , Saxena Pramod R , Sterk Peter J , de Boer Willem I , Sharma Hari S
Published: March 2005

An important feature of chronic obstructive pulmonary disease (COPD) is airway remodelling, the molecular mechanisms of which are poorly understood. In this study, the role of fibroblast growth factors (FGF‐1 and FGF‐2) and their receptor, FGFR‐1, was assessed in bronchial airway wall remodelling in patients with COPD (FEV1 < 75%; n = 15) and without COPD (FEV1 > 85%; n = 16). FGF‐1 and FGFR‐1 were immunolocalized in bronchial epithelium, airway smooth muscle (ASM), submucosal glandular epithelium, and vascular smooth muscle. Quantitative digital image analysis revealed increased cytoplasmic expression of FGF‐2 in bronchial epithelium (0.35 ± 0.03 vs 0.20 ± 0.04, p < 0.008) and nuclear localization in ASM (p < 0.0001) in COPD patients compared with controls. Elevated levels of FGFR‐1 in ASM (p < 0.005) and of FGF‐1 (p < 0.04) and FGFR‐1 (p < 0.001) in bronchial epithelium were observed. In cultured human ASM cells, FGF‐1 and/or FGF‐2 (10 ng/ml) induced cellular proliferation, as shown by [3H]thymidine incorporation and by cell number counts. Steady‐state mRNA levels of FGFR‐1 were elevated in human ASM cells treated with either FGF‐1 or FGF‐2. The increased bronchial expression of fibroblast growth factors and their receptor in patients with COPD, and the mitogenic response of human ASM cells to FGFs in vitro suggest a potential role for the FGF/FGFR‐1 system in the remodelling of bronchial airways in COPD. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
PRDM1/Blimp‐1 is expressed in human B‐lymphocytes committed to the plasma cell lineage
Authors: Cattoretti Giorgio , Angelin‐Duclos Cristina , Shaknovich Rita , Zhou Huiping , Wang Denong , Alobeid Bachir
Published: March 2005

PRDM1/Blimp‐1 (in human and mouse, respectively) has a central role in determining and shaping the secretory arm of mature B‐cell differentiation. In this study, a mouse monoclonal antibody that recognizes PRDM1 was used to detail its distribution in normal human lymphoid tissue and in lymphoid neoplasms that correspond to different stages of B‐cell differentiation. PRDM1 was expressed in germinal centre blasts that co‐express Pax5, CD19, CD20, and CD10, but not BCL6 or MTA‐3. Pax5 was downregulated and full plasma cell morphology and phenotype were acquired by PRDM1+, nuclear cREL−, pre‐plasma cells upon exit from the germinal centre. Activated extrafollicular B‐cells (CD30+, Pax5+) were largely PRDM1−. PRDM1 was also absent in tissue histiocytes and the majority of resting T‐cells and S‐100+ antigen‐presenting cells. PRDM1 and CD138 were expressed simultaneously in human lymphomas with plasma cell differentiation, but not in marginal zone lymphomas or chronic lymphocytic leukaemias. A minority of diffuse large B‐cell lymphomas expressed PRDM1 and Hodgkin lymphomas were largely PRDM1−. Infiltrating T‐cells in PRDM1− B‐cell lymphomas expressed PRDM1. In conclusion, PRDM1 staining is a reliable and informative assay to define plasma cell commitment and differentiation in human normal and neoplastic B‐cell lineages. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
New poly(oxyethylene) derivatives and their oligo analogues from Diels–Alder reactions of 5‐[methoxypoly(oxyethylene)]‐(3E)‐1, 3‐pentadiene and 5‐methoxyethoxy‐(3E)‐1,3‐pentadiene
Authors: Hopkins Timothy E. , Park Moa , Chacon Almary , Sedaghat‐Herati Reza
Published: March 2005

Diels–Alder reactions of 5‐[methoxypoly(oxyethylene)]‐(3E)‐1,3‐pentadiene (1a) with maleic anhydride, diethyl acetylenedicarboxylate (DADC), and acrolein were investigated for the synthesis of new poly(ethylene glycol) derivatives. To facilitate the characterization of the derivatives, Diels–Alder reactions of 5‐methoxyethoxy‐(3E)‐1,3‐pentadiene (1b) with the aforementioned dienophiles were also studied. The reaction of o‐toluidine with the cycloaddition product from maleic anhydride and 1b resulted in the corresponding amide products. The reactions of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone with cycloadducts derived from 1a and 1b with DADC resulted in the aromatization of the corresponding products. An NMR analysis of the adducts obtained from 1a and acrolein in water and from 1b and acrolein in water/acetonitrile (4:1 v/v) indicated a mixture of endo and exo, with the endo concentration being approximately 80%. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 1895–1902, 2005
Sequence–structure–function relationships of a tRNA (m7G46) methyltransferase studied by homology modeling and site‐directed mutagenesis
Authors: Purta Elżbieta , van Vliet Françoise , Tricot Catherine , De Bie Lara G. , Feder Marcin , Skowronek Krzysztof , Droogmans Louis , Bujnicki Janusz M.
Published: March 2005

The Escherichia coli TrmB protein and its Saccharomyces cerevisiae ortholog Trm8p catalyze the S‐adenosyl‐L‐methionine‐dependent formation of 7‐methylguanosine at position 46 (m7G46) in tRNA. To learn more about the sequence–structure–function relationships of these enzymes we carried out a thorough bioinformatics analysis of the tRNA:m7G methyltransferase (MTase) family to predict sequence regions and individual amino acid residues that may be important for the interactions between the MTase and the tRNA substrate, in particular the target guanosine 46. We used site‐directed mutagenesis to construct a series of alanine substitutions and tested the activity of the mutants to elucidate the catalytic and tRNA‐recognition mechanism of TrmB. The functional analysis of the mutants, together with the homology model of the TrmB structure and the results of the phylogenetic analysis, revealed the crucial residues for the formation of the substrate‐binding site and the catalytic center in tRNA:m7G MTases. Proteins 2005. © 2005 Wiley‐Liss, Inc.
The Utilization of Solid State Chemistry Reaction Routes as New Syntheses Strategies for the Coordination Chemistry of Rare Earth Amides
Authors: Müller‐Buschbaum Klaus
Published: March 2005

Solvent free high‐temperature reactions in melts are well known procedures in Solid‐State Chemistry. Although the reaction conditions are extreme considering the properties of organic ligands they can also be utilized for Coordination Chemistry and offer a fruitful alternative to usual solvent treatments. This includes the chemistry of organic amides of the rare earth elements. The avoidance of any solvent renders novel homoleptic complexes accessible but also implies difficulties bound to the solid state of the reaction mixtures. The high chemical affinity of the rare earth elements towards halides and especially oxygen limits known homoleptic amides obtained via solvent treatments mostly to multi‐chelating ligands like porphyrines, calix‐pyrroles etc. With no special conditions met like a high steric demand, solvent molecules as co‐coordinating partners enforce the formation of heteroleptic species. This influence can be avoided by the use of completely solvent free reactions, such as melt reactions in which a solid is reacted directly with a melt or with a substance under solvothermal conditions. The high reactivity of the rare earth metals allows the direct oxidation with amines and thus to use high‐temperature reactions for the formation of rare earth amides. This includes homoleptic compounds from simple ligands. Crystallization under reaction conditions is possible; no re‐crystallization step is necessary preventing the risk of a change of the chemical character of the products.

Additionally, the solubility of rare earth elements in liquid ammonia under formation of an electride solution enlarges the temperature range of these oxidation reactions down to the melting point of ammonia. It further enhances the reactivity of the metals and less N‐H acidic and thermally less stable amines can be introduced into these syntheses enabling the formation of meta stable products. The crystal structures and hence the properties of the products of both high‐ and low‐temperature oxidation of rare earth metals with amines strongly differ from reactions carried out in classic solvents. Thus reaction routes frequently used in Solid State Chemistry can well be utilized for Coordination Chemistry and offer alternatives to classic solvent based synthesis, particularly if certain properties like homoleptic character or the coordination of elements with a low chemical affinity are aimed for.
The Iminoborane tBuB≡NtBu as a Dipolarphile in (2+3) Cycloadditions
Authors: Kröckert Bernd , van Bonn Karl‐Heinz , Paetzold Peter
Published: March 2005

The iminoborane tBuB≡NtBu and the diazomethane tBuCH=N2 give the (2+3) cycloadduct [—HC(tBu)—N=N—N(tBu)=B(tBu)—] in a 1:1 reaction and the seven‐membered ring [—C(tBu)=N—NH—N(tBu)=B(tBu)—N(tBu)=B(tBu)—] in a 2:1 reaction. The (2+3) cycloadduct decomposes above 0 °C to give the seven‐membered ring, N2, and HC(tBu)=N—N=CH(tBu) in the ratio 2:1:1. The borane tBuB≡NtBu and organic azides R″N3 yield the (2+3) cycloadducts [—R″N—N=N—N(tBu)=B(tBu)—] (R″ = Me, Et, Pr, Bu, iBu, sBu, C5H11, c‐C5H9, c‐C6H11, Bzl, EtOOC).
α‐Gluthathione S‐Transferase as an Early Marker of Hepatic Ischemia/Reperfusion Injury after Liver Resection
Authors: Choukér Alexander , Martignoni André , Schauer Rolf J. , Dugas Martin , Schachtner Thomas , Kaufmann Ines , Setzer Florian , Rau Horst G. , Löhe Florian , Jauch Karl‐W. , Peter Klaus , Thiel Manfred
Published: March 2005

Organ dysfunction following liver resection is one of the major postoperative complications of liver surgery. The Pringle maneuver is often applied during liver resection to minimize bleeding, which in turn complicates the postoperative course owing to liver ischemia and reperfusion. Routinely, hepatocellular damage is diagnosed by, for example, abnormal aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels and the prothrombin time (PT). The cytosolic liver enzyme α‐glutathione S‐transferase (α‐GST) has recently been shown to have good sensitivity for detecting hepatic injury after acetaminophen poisoning or liver transplantation, but its role in non‐transplantation liver surgery has not been assessed. In this prospective randomized clinical study, the diagnostic role of plasma α‐GST following warm ischemia and reperfusion is reported. A total of 75 patients who underwent liver resection were randomly assigned to three groups: (1) without Pringle (NPR); (2) with Pringle (PR); (3) with ischemic preconditioning by 10 minutes of ischemia and reperfusion each prior to the Pringle manuever (IPC). The major findings are as follows: (1) ALT, AST, and α‐GST increased upon liver manipulation as early as prior to resection, with a rapid return of α‐GST values to preoperative levels, whereas ALT and AST further increased on the first postoperative day. (2) In the PR group, α‐GST, but not ALT and AST, was significantly elevated compared with that in the NPR group at 15 and 30 minutes and 2 hours after resection/reperfusion. In addition, only levels of α‐GST significantly correlated with the Pringle duration. (3) The ischemia/reperfusion‐induced early rise in α‐GST was completely prevented by ischemic preconditioning. Moreover, only α‐GST concentrations (>490 μg L−1) determined early after resection (2 hours) predicted postoperative liver dysfunction (24 hours PT < 60%) with a positive predictive value of 74% and a negative predictive value of 76%. Thus α‐GST seems to be a sensitive, predictive marker of ischemia/reperfusion‐induced hepatocellular injury and postoperative liver dysfunction.
The Effect of Experiential Knowledge on Construction of Risk Perception in Hereditary Breast/Ovarian Cancer
Authors: d'Agincourt‐Canning Lori
Published: March 2005

The purpose of this study was to explore the connection between experiential knowledge of hereditary breast/ovarian cancer and understandings of personal cancer risk. Using a qualitative research design, the investigator conducted in‐depth interviews with 53 individuals (45 female, 8 male) from families at high‐risk for hereditary breast/ovarian cancer. Study results showed that two forms of experiential knowledge, empathetic and embodied knowledge, were integral to participants’ constructions of their cancer risk. They also illustrated that knowledge derived from experience often took precedence over objective clinical estimates of risk. The paper discusses the clinical implications of these findings and suggests that counseling strategies, which expand upon patient's lived experience and knowledge of the disease, may enhance communication of genetic risk. Assessment of experiential knowledge promises to suggest new ways to frame genetic information that will enable people to better understand their objective risk or to modify exaggerated and/or inaccurate risk perceptions.
Peptide Hydrophobicity and Partitioning in Poly (ethylene glycol)/ Magnesium Sulfate Aqueous Two‐Phase Systems
Authors: Eiteman Mark A. , Gainer John L.
Published: March 2005

Several amino acids and peptides were partitioned in poly (ethylene glycol) (PEG)/ magnesium sulfate (MgSO4) aqueous two‐phase systems. The partition coefficients measured for amino acids and peptides were proportional to the difference in PEG concentration between the phases. The partitioning data were used to calculate the relative hydrophobicities of individual amino acids, which were then used to estimate the hydrophobicities of peptides. The partition coefficients of several dipeptides were predicted from these estimated hydrophobicities. A series of peptide fragments that compose the pentapeptide leucine enkephalin was also partitioned in the PEg/ MgSO4 system. Again, the partitioning depended upon the hydrophobicities of the individual exposed amino acids.
Application of Pseudomonas putida PpG 786 Containing P‐450 Cytochrome Monooxygenase for Removal of Trace Naphthalene Concentrations
Authors: Kulisch Gail P. , Vilker Vincent L.
Published: March 2005

This study explores the potential for a bacterial monooxygenase to remove polynuclear aromatic hydrocarbons from aqueous solutions at high rates. This is part of a larger effort to test the versatility of the cytochrome P‐450cam monooxygenase enzyme system for detoxification of industrial process wastewaters that contain trace quantities of hazardous compounds like PAHs or halocarbons. The intracellular concentration of P‐450cam in washed, resting cell suspensions of Pseudomonoas putida PpG 786 that were cultured on camphor was measured by adapting a spectrophotometric method used to measure P‐450 concentration in extracts of mammalian tissues. Naphthalene removal in the suspensions was measured as a function of incubation time, biomass concentration, starting naphthalene concentration (3‐180 μmol/L) and in the presence of known P‐450 inhibitors. Involvement of the P‐450cam system in the measured naphthalene disappearance was established by showing that while significant naphthalene removal occurred in camphor‐grown biomass, no disappearance was observed in glutamate‐grown biomass and that removal was turned off in the presence of the P‐450 inhibitor metyrapone. The half‐life of naphthalene removal for a 1 ppm solution (7.8 μM) was about 18 h. The fraction of naphthalene removed descreased rapidly as initial naphthalene concentration increased, and essentially no naphthalene was removed when the starting concentration exceeded 189 μmol/L (23 ppm).
Antibody Immobilization onto Glow Discharge Treated Polymers
Authors: Safranj Agneza , Kiaei David , Hoffman Allan S.
Published: March 2005

Previous studies have shown that certain glow discharge treated polymers strongly retain adsorbed albumin and fibrinogen. On the basis of this phenomenon, we have investigated the possibility of immobilizing antibodies on glow discharge treated surfaces for diagnostic immunoassay applications. As a model for antibody immobilization, bovine IgG was immobilized on the following polymers: polyethylene (PE), tetraflu‐oroethylene glow discharge treated PE (TFE/PE), poly(ethylene terephthalate) (PET), TFE/PET, poly(tetrafluoroethylene) (PTFE), ethylene glow discharge treated PET (E/PET) and hexamethyldisiloxane glow discharge treated PET (HMDS/PET). IgG was radiolabeled with 125I and immobilized by either of the following two methods: (a) physical adsorption of IgG on untreated and glow discharge treated polymers or (b) physical adsorption of albumin followed by chemical coupling of IgG to albumin by glutaraldehyde. IgG concentration as well as adsorption times were varied in order both to optimize the immobilization conditions and to investigate the adsorption and retention mechanisms. To evaluate the efficiency of the immobilization techniques, blood plasma, Tween‐20, and sodium dodecyl sulfate (SDS) were used to elute the adsorbed IgG layer. We found that IgG was successfully immobilized on the fluorocarbon glow discharge treated surfaces by using either the physical adsorption or the glutaraldehyde coupling method, although the former is more efficient than the latter method. Only 15% of the IgG adsorbed on TFE/PE for 4 h was eluted by SDS. In contrast, 75% of the IgG was eluted from untreated PE by SDS. Both Tween‐20 and blood plasma were less effective than SDS in eluting the adsorbed IgG. Preliminary results indicate that antibodies immobilized by the first method retain their antigen binding capability.
High‐Resolution Particle Size Analysis in Biotechnology Process Control
Authors: Thomas John C. , Middelberg Anton P. J. , Hamel Jean‐Francois , Snoswell Mark A.
Published: March 2005

Many industrially important proteins can now be expressed intracellularly as insoluble protein inclusion bodies. In production, large‐scale centrifugation is commonly used to separate and recover the inclusion bodies. Recovery efficiency depends critically on the centrifuge feed rate, which must be optimized to minimize production costs. We have used a disc centrifuge photosedimentometer to make high‐resolution measurements of the particle size distribution (PSD) of the supernatant during the production of porcine somatotropin (pST) inclusion bodies. These measurements readily monitor the breakthrough of inclusion bodies into the supernatant and allow the centrifugation operation to be optimized.
Determination of the Effect of Moisture on Gliadin Glass Transition Using Mechanical Spectrometry and Differential Scanning Calorimetry
Authors: Graaf E. M. De , Madeka H. , Cocero A. M. , Kokini J. L.
Published: March 2005

Gliadin showed a glass to rubber transition typical of an amorphous polymer. Mechanical spectrometry and differential scanning calorimetry were used to determine the glass transition temperature (Tg) in the moisture range of 6.2–27.2% (wet basis, wb) and bone dry to 16.6% (wb), respectively. The Tg obtained with both of these techniques could be superimposed. The Tg could be successfully predicted using the Gordon‐Taylor equation.
Optimization of Baker's Yeast Alcohol Dehydrogenase Activity in an Organic Solvent
Authors: Yang Fangxiao , Russell Alan J.
Published: March 2005

Alcohol dehydrogenase from baker's yeast (YADH) has been used to oxidize an unsaturated alcohol, 3‐methyl‐2‐buten‐l‐ol (UOL), to the corresponding unsaturated aldehyde, 3‐methyl‐2‐butenal (UAL), in heptane. The influence of total system water content, coenzyme NAD to enzyme molar ratio prior to catalyst preparation, and enzyme concentration on the conversion and redox reaction rates were investigated. The optimal water content was found to be 0.25‐0.5% (v/v), and a molar ratio of NAD to enzyme of 2.15 is recommended on the basis of economic and kinetic data. A maximal initial reaction rate for YADH of 0.02 mM/min/mg was observed under optimal conditions. The minimum cofactor turnover number was also determined under all conditions, and the effect of doping the catalyst with extra binding sites for NAD was investigated. The effect of substrate on enzyme stability has also been investigated. Interestingly, when the enzyme is preincubated in heptane, its initial activity can be increased 3‐fold.
Glycosidase Activities in Chinese Hamster Ovary Cell Lysate and Cell Culture Supernatant
Authors: Gramer Michael J. , Goochee Charles F.
Published: March 2005

To probe the potential for extracellular degradation of glycoprotein oligosaccharides in conjunction with Chinese hamster ovary (CHO) cell culture, an initial characterization of several CHO cell glycosidases was performed using 4‐methylumbelliferyl substrates. CHO cell lysates contained sialidase, β‐galactosidase, β‐hexosaminidase, and fucosidase activities with pH optimums near 5.5, 4, 6, and 6.5, respectively. These glycosidase activities were also present in cell‐free supernatant samples from commercial CHO cell cultures. The sialidase activity was further characterized. In contrast to previous reports concerning mammalian sialidases, the sialidase activity in CHO cell lysate retained considerable activity at pH 7 and was very stable, with a half‐life of 57 h at 37°C. Both the Km and Vmax of CHO lysate sialidase for 2′–(4‐methylumbelliferyl)‐a‐D‐N‐acetylneuraminic acid (4MU‐NeuAc) varied with pH, and this activity was competitively inhibited by 2, 3‐dehydro‐2‐deoxy‐N‐acetylneuraminic acid and by free N‐acetylneuraminic acid. The kinetic characteristics and pH‐activity profiles of the CHO cell lysate and cell culture supernatant sialidase activities were essentially identical, and both released sialic acid from the glycoprotein fetuin at pH 7.5. These results suggest that the oligosaccharides of glycoproteins secreted by CHO cells can potentially be modified extracellularly by sialidase under culture conditions which promote the release and extracellular accumulation of this enzyme.
Reversed Micellar Extraction of Charged Fusion Proteins
Authors: Forney Craig E. , Glatz Charles E.
Published: March 2005

We have investigated the use of charged fusion tails with the enzyme glucoamylase in reversed micellar extraction. The addition of the charged tails increased the fraction of enzymatically active protein recovered at a given pH, with the tails containing the largest number of charges being recovered at the highest level. The series of mutations also allows for investigation of the charge‐dependent behavior of reversed micellar extraction. However, in this case, the change in protein charge via fusions had a lesser impact than did the change in charge via a pH change. The difference may be due to the difficulty of partitioning the hydrodynamically larger fusion protein.
Meddies in the Mercator North Atlantic and Mediterranean Sea eddy‐resolving model
Authors: Drillet Yann , Bourdallé‐Badie Romain , Siefridt Laure , Le Provost Christian
Published: March 2005

The new generation of high‐resolution ocean models offers a new way to investigate the characteristics and the evolution of the ocean mesoscale. An analysis of the simulated Mediterranean eddies, the so‐called “meddies,” is presented. The model used in this study is the Mercator North Atlantic [9°N, 70°N] and Mediterranean Sea Prototype (PAM), a high‐resolution configuration (3.5–8 km horizontal grid) based on the OPA ocean general circulation model. The meddies are coherent structures of warm and salt Mediterranean Water (MW) advected in the northeast Atlantic. A 5 year experiment performed with PAM reproduced the main observed characteristics of the meddies: thermohaline properties (11.8°C, 36 psu), sizes (radius between 25 and 110 km), thickness (between 500 and 1000 m), westward advection velocities (1.4 cm.s−1), angular velocities (a period of 20 days), a good estimate of the number of meddies in the northeast Atlantic (∼22), and their realistic geographical distribution (80% south of 40°N). Moreover, and in agreement with a previous study based on an observation cruise, these modeled meddies represent half of the westward salinity transport of MW.
Mean radiative energy balance and vertical mass fluxes in the equatorial upper troposphere and lower stratosphere
Authors: Corti T. , Luo B. P. , Peter T. , Vömel H. , Fu Q.
Published: March 2005

We use radiative transfer calculations to quantify vertical mass transport in the equatorial upper troposphere (UT) and lower stratosphere (LS), employing high resolution sonde measurements of temperature, ozone and water vapor at seven equatorial locations (10°S–10°N). The influence of clouds is examined using data from the International Satellite Cloud Climatology Project (ISCCP) and the Lidar‐In‐Space Technology Experiment (LITE). The resulting mean heating rate profiles show that the transition from radiative cooling to heating occurs significantly lower in the full sky case than in the clear sky case, demonstrating the importance of clouds for processes in the UT, such as troposphere‐to‐stratosphere transport (TST). The heating rate profiles are used to calculate mean vertical mass fluxes, which show a divergent mass flux from 15–19 km. This suggests that only a small part of the air ascending through the cold point tropopause can reach the middle stratosphere. Above 19 km the vertical motion is a non‐divergent upwelling mass flux consistent with the idea of a Brewer‐Dobson circulation driven by waves dissipating in the extratropical stratosphere. Lower down, other processes are also responsible for the upwelling.
Auroral particles associated with a substorm brightening arc
Authors: Yago K. , Shiokawa K. , Hayashi K. , Yumoto K.
Published: March 2005

We investigated the characteristics of auroral precipitating particles associated with a brightened arc at a pseudo‐substorm, using auroral images of a high‐time resolution (0.25 s) all‐sky TV camera, particle data from the DMSP F10 spacecraft, and high‐latitude magnetograms. The arc brightening occurred at 0407 UT (∼20 MLT) on December 30, 1994, at Fort Smith (67 MLAT), Canada, coincident with high‐latitude Pi 2 magnetic pulsations. The brightening appeared without expansion (pseudo‐breakup), and Fort Smith was located duskside of the main onset region. From the simultaneous DMSP particle data, the brightened arc is found to correspond to an electron inverted‐V structure near the equatorward edge of the electron precipitation region, suggesting the pseudo‐breakup of the auroral substorm occurred in the inner part of the plasma sheet.
Satellite on‐board temperatures: Proxy measurements of Earth's climate changes?
Authors: Casadio Stefano , di Sarra A. , Pisacane G.
Published: March 2005

Changes in Earth's outgoing radiance are expected to affect the thermal equilibrium of spaceborne instruments, and to produce detectable variations of satellite on‐board temperatures (OBTs). In this study, temperatures of the Global Ozone Monitoring Experiment during the period July 1995–July 2004 have been analysed. Results show that GOME temperatures are influenced by solar flux variations and strongly driven by radiation fluxes from the Earth. The long‐term behaviour of the GOME OBT is characterized by periodicities related to orbital and atmospheric phenomena, and by a steady increase, starting from year 1998. The behaviour of OBTs is consistent with the evolution of the observed shortwave radiative forcing from earthshine observations. The advantage of this technique resides in its simplicity. The proposed approach could be applied to all previous, current and future satellite instruments with thermal characteristics similar to GOME, providing a long time series of a proxy indicator of Earth climate.
Bilirubin Production and Oxidation in CSF of Patients with Cerebral Vasospasm after Subarachnoid Hemorrhage
Authors: Pyne-Geithman Gail J , Morgan Chad J , Wagner Kenneth , Dulaney Elizabeth M , Carrozzella Janice , Kanter Daniel S , Zuccarello Mario , Clark Joseph F
Published: March 2005

Delayed cerebral vasospasm after subarachnoid hemorrhage (SAH) remains a significant cause of mortality and morbidity; however, the etiology is, as yet, unknown, despite intensive research efforts. Research in this laboratory indicates that bilirubin and oxidative stress may be responsible by leading to formation of bilirubin oxidation products (BOXes), so we investigated changes in bilirubin concentration and oxidative stress in vitro, and in cerebral spinal fluid (CSF) from SAH patients. Non-SAH CSF, a source of heme oxygenase I (HO-1), and blood were incubated, and in vitro bilirubin production measured. Cerebrospinal fluid from SAH patients was collected, categorized using stimulation of vascular smooth muscle metabolism in vitro, and information obtained regarding occurrence of vasospasm in the patients. Cerebral spinal fluid was analyzed for hemoglobin, total protein and bilirubin, BOXes, malonyldialdehyde and peroxidized lipids (indicators of an oxidizing environment), and HO-1 concentration. The formation of bilirubin in vitro requires that CSF is present, as well as whole, non-anti-coagulated blood. Bilirubin, BOXes, HO-1, and peroxidized lipid content were significantly higher in CSF from SAH patients with vasospasm, compared with nonvasospasm SAH CSF, and correlated with occurrence of vasospasm. We conclude that vasospasm may be more likely in patients with elevated BOXes. The conditions necessary for the formation of BOXes are indeed present in CSF from SAH patients with vasospasm, but not CSF from SAH patients without vasospasm.
Cerebral Blood Flow and Brain Oxygenation in Rats Breathing Oxygen under Pressure
Authors: Demchenko Ivan T , Luchakov Yuriy I , Moskvin Alexander N , Gutsaeva Diana R , Allen Barry W , Thalmann Edward D , Piantadosi Claude A
Published: March 2005

Hyperbaric oxygen (HBO2) increases oxygen tension (PO2) in blood but reduces blood flow by means of O2-induced vasoconstriction. Here we report the first quantitative evaluation of these opposing effects on tissue PO2 in brain, using anesthetized rats exposed to HBO2 at 2 to 6 atmospheres absolute (ATA). We assessed the contribution of regional cerebral blood flow (rCBF) to brain PO2 as inspired PO2 (PiO2) exceeds 1 ATA. We measured rCBF and local PO2 simultaneously in striatum using collocated platinum electrodes. Cerebral blood flow was computed from H2 clearance curves in vivo and PO2 from electrodes calibrated in vitro, before and after insertion. Arterial PCO2 was controlled, and body temperature, blood pressure, and EEG were monitored. Scatter plots of rCBF versus pO2 were nonlinear ( R2 = 0.75) for rats breathing room air but nearly linear ( R2 = 0.88–0.91) for O2 at 2 to 6 ATA. The contribution of rCBF to brain PO2 was estimated at constant inspired PO2, by increasing rCBF with acetazolamide (AZA) or decreasing it with N-nitro-l-arginine methyl ester (l-NAME). At basal rCBF (78 mL/100 g min), local PO2 increased 7- to 33-fold at 2 to 6 ATA, compared with room air. A doubling of rCBF increased striatal PO2 not quite two-fold in rats breathing room air but 13- to 64-fold in those breathing HBO2 at 2 to 6 ATA. These findings support our hypothesis that HBO2 increases PO2 in brain in direct proportion to rCBF.
Effects of growth temperature on the structural and magnetic properties of epitaxial Ni2MnIn thin films on InAs (001)
Authors: Xie J. Q. , Lu J. , Dong J. W. , Dong X. Y. , Shih T. C. , McKernan S. , Palmstrøm C. J.
Published: March 2005

Heusler alloy Ni2MnIn thin films have been grown on InAs (001) by molecular beam epitaxy at growth temperatures ranging from 120 to 300 °C. For growth at 120 °C, transmission electron diffraction confirms the epitaxial growth of Ni2MnIn in the B2 crystal structure on InAs (001) with an epitaxial relationship of Ni2MnIn(001)⟨100⟩‖InAs(001)⟨100⟩. Magnetic measurements show that the Ni2MnIn film is ferromagnetic with a Curie temperature ∼170K. However, for growth at 120 °C followed by a postgrowth anneal at 200 °C, a Curie temperature as high as 330 K was obtained. The increase in Curie temperature is attributed to the formation of partial L21 ordering in the Ni2MnIn film, as determined by convergent beam electron diffraction.
Light intensity dependence of open-circuit voltage of polymer:fullerene solar cells
Authors: Koster L. J. A. , Mihailetchi V. D. , Ramaker R. , Blom P. W. M.
Published: March 2005

The open-circuit voltage Voc of polymer:fullerene bulk heterojunction solar cells is investigated as a function of light intensity for different temperatures. Devices consisted of a blend of a poly(p-phenylene vinylene) derivative as the hole conductor and 6,6-phenyl C61-butyric acid methyl ester as the electron conductor. The observed photogenerated current and Voc are at variance with classical p–n junction-based models. The influence of light intensity and recombination strength on Voc is consistently explained by a model based on the notion that the quasi-Fermi levels are constant throughout the device, including both drift and diffusion of charge carriers.