bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of pentavalent imidovanadium complexes and their catalyses for the polymerization of ethylene and propylene
Authors: Sato Yoshinori , Nakayama Yuushou , Yasuda Hajime
Published: May 2005

Imidovanadium complexes with cyclopentadienyl (Cp) ligands—(Cp)V(NC6H4Me‐4)Cl2 (1), (Cp)V(NtBu)Cl2 (2), and (tBuCp)V(NtBu)Cl2 (3; tBuCp = tert‐butylcyclopentadienyl)—were synthesized through the reaction of imidovanadium trichloride with (trimethylsilyl)cyclopentadiene derivatives. The molecular structure of 3 was determined by X‐ray crystallography. The monocyclopentadienyl complex 1 exhibited moderate activity in combination with methylaluminoxane [MAO; 10.3 kg of polyethylene (mol of V)−1 h−1 atm−1], whereas similar complexes with bulky tBu groups, 2 and 3, were less active. (2‐Methyl‐8‐quinolinolato)imidovanadium complexes, V(NR)(O ˆN)Cl2 (R = C6H3iPr2‐2,6 (4) or n‐hexyl (5), O ˆN = 2‐methyl‐8‐quinolinolato), were obtained from the reaction of imidovanadium trichloride with 2‐methyl‐8‐quinolinol. Upon activation with modified MAO, complex 4 showed moderate activities for the polymerization of ethylene at room temperature. The complex 5/MAO system also exhibited moderate activity at 0°C. The polyethylenes obtained by these complexes had considerably high melting points, which indicated the formation of linear polyethylene. Moreover, the 5/dried MAO system showed propylene polymerization activities and produced polymers with considerably high molecular weights and narrow molecular weight distributions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1008–1015, 2005
Photopolymerization kinetics of dimethacrylate‐based light‐cured dental resins
Authors: Davidenko N. , García O. , Sastre R.
Published: May 2005

The influence of certain factors [structure and concentration of tertiary amines as coinitiators, monomer composition, presence of inorganic pigments, and incident light intensity (I0)] on the polymerization rates (Rp), polymerization quantum yields, and conversions of bisphenol A–bis(glycidyl methacrylate) (Bis‐GMA)/triethylene glycol dimethacrylate based resins was studied. The initial rate of bulk polymerization increased and the final conversion decreased with the content of Bis‐GMA in the mixture. In contrast, it was established that, for all monomer compositions, the Rp grew when increasing the I0, the Rp being directly proportional to the square root of I0. Such behavior is in agreement with the well‐known kinetic expression for the ideal radical photoinitiated polymerization in solution of monofunctional monomers, in spite of the complexity of the dimethacrylate mixtures that were studied. Both the structure and the concentration of reducing amine affected the efficiency of the initiator system and therefore the kinetic behavior of polymerization of these formulations under irradiation. The rate of polymerization increased with the increase of coinitiator concentration over the interval of 0–1%, but later it diminished when increasing the amine content, suggesting that the excess coinitiator retards the polymerization process. The study of the photoreduction of camphorquinone in the presence of different amines showed that the efficiency of the coinitiator depends not only on its ability to photoreduce camphorquinone, forming amine‐derived radicals, but also on the reactivity of these radicals toward the initiation of acrylic monomer polymerization. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1016–1023, 2005
Proper finishing treatments for sun‐protective cotton‐containing fabrics
Authors: Ibrahim N. A. , Refai R. , Youssef M. A. , Ahmed A. F.
Published: May 2005

To enhance both the performance and ultraviolet‐protection properties of cotton‐containing fabrics, attempts have been made to use poly(carboxylic acid)s as non‐formaldehyde durable‐press finishing agents alone or in combination with certain additives followed by posttreatment with metal salt solutions. Furthermore, simultaneous dyeing and resin finishing in the presence of triethanolamine hydrochloride (TEA · HCl) or citric acid (CA) as a reactive additive along with different anionic or cationic dyestuffs have been examined. The results reveal that the ester crosslinking of cotton‐containing fabrics in the absence or presence of chitosan (5 g/L), β‐cyclodextrin (20 g/L), or choline chloride (20 g/L) as an additive results in an improvement in the fabric resiliency as well as the ultraviolet‐protection properties. The extent of the improvement is determined by the type of poly(carboxylic acid), type of additive, type of substrate (i.e., cotton or cotton/polyester blend), and pretreatment history (i.e., grey, bleached, or bleached and mercerized). The posttreatment of easy‐care finished fabric samples with a copper acetate solution (5 g/L) results in a dramatic improvement in the ultraviolet‐protection factor, especially with bleached cotton, grey cotton/polyester blend, and bleached cotton/polyester fabric samples, regardless of the additive. Simultaneous dyeing and resin finishing with Reactive Black 5 and Direct Violet 31, in the presence of TEA · HCL as a reactive additive, or with Basilene Red PB, in the presence of CA as a reactive additive, result in a sharp increase in both the depth of shade and the ultraviolet‐protection values, regardless of the substrate. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1024–1032, 2005
Swelling behavior of gelatin‐g‐poly(butyl acrylate) copolymers
Authors: Zheng Jun Ping , Wang Jian Xun , Gao Shan , Yao Kang De
Published: May 2005

Gelatin‐g‐poly (butyl acrylate) copolymers were prepared with gelatin and butyl acrylate. The effects of various reaction parameters, including the concentration of the monomer, the concentration of the initiator, the concentration of gelatin, the reaction time, and the temperature, on the swelling behavior were studied systematically. In addition, the effect of the intercalation of graft copolymers with montmorillonite on the swelling behavior was investigated. The results indicated that the graft copolymerization and intercalation with montmorillonite could greatly reduce the swelling degree of gelatin. The swelling process of the copolymers followed second‐order kinetics identical to those of the original gelatin. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1033–1037, 2005
Feasibility evaluation of chitosan coatings on polyethylene tubing for biliary stent applications
Authors: Lin Chih‐Hsiu , Lin Jui‐Che , Chen Chiung‐Yu , Cheng Chu‐Yuan , Lin Xi‐Zhang , Wu Jiunn‐Jong
Published: May 2005

Endoscopic palliation for the obstructive jaundice caused by biliary or pancreatic malignant tumors is a commonly used medical treatment. However, plastic biliary stents are occluded by sludge deposition caused by bacterial adhesion in 3–5 months. Chitosan, which has both good biocompatibility and antimicrobial capability, was used to modify the inner surface of polyethylene (PE) tubing in this study. Chitosan was deposited onto the inner surface of oxidized PE tubing with the methanol precipitation technique. Attenuated total reflection/Fourier transform infrared and electron spectroscopy for chemical analysis indicated that the chitosan coating was feasible. Contact‐angle measurements revealed that the surface hydrophilicity of the PE tubing increased with the chitosan coating. Morphological analysis with scanning electron microscopy showed that the PE surface became rougher and exhibited micropores after the chitosan coating. The adhesion of living Escherichia coli to chitosan‐coated PE stents, characterized by the spreading plate method and scanning electron microscopy analysis, was more significant than that to unmodified stents after a 24‐h phosphate‐buffered saline or bile perfusion test. This finding may be attributed to the rougher and slightly positively charged surface of chitosan‐coated PE tubing and to the CH3 hydrophobic functional groups in the chitosan structure. Because of its good biocompatibility, chitosan coated on the surface of PE can still be used for biliary stent applications with further chemical modification, such as sulfonation and quaternization, to increase its antimicrobial ability. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 893–902, 2005
Development of thermoregulating textile materials with microencapsulated phase change materials (PCM). IV. Performance properties and hand of fabrics treated with PCM microcapsules
Authors: Shin Younsook , Yoo Dong‐Il , Son Kyunghee
Published: May 2005

Polyester knit fabrics were treated with phase‐change‐material microcapsules by a pad–dry–cure method with a polyurethane binder. The treated fabrics were evaluated in terms of the thermal properties, air permeability, moisture vapor permeability, moisture regain, low‐stress mechanical properties, and hand, with respect to the add‐on of microcapsules. The surface morphology of the treated fabrics was investigated with scanning electron microscopy. The low‐stress mechanical properties of the treated fabrics, including the tensile, shear, bending, surface, and compression properties, were measured with the Kawabata evaluation system for fabrics (KES‐FB). As the add‐on increased, the heat storage capacity of the treated fabrics increased. The treated fabric with 22.9% add‐on was capable of absorbing 4.44 J/g of heat. The air permeability and moisture vapor permeability decreased, whereas the moisture regain increased, with an increase in the add‐on. The tensile linearity and geographical roughness increased, whereas the resilience, bending, and shear properties decreased with an increase in the add‐on. The fabrics became stiffer, less smooth, and less full as the add‐on increased, and thus the total hand value decreased. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 910–915, 2005
Particleboards from peanut‐shell flour
Authors: Batalla Leonel , Nuñez Adrián J. , Marcovich Norma E.
Published: May 2005

Peanuts have been cultivated worldwide for hundreds, if not thousands, of years. However, most peanuts are sold without the shell, and so large quantities of peanut shells remain as byproducts in the field, not being used properly. In this work, the feasibility of making particleboard from milled peanut shells was studied. To obtain medium‐density panels, a low compaction pressure and a high fiber content were used. The physical and mechanical properties of the panels were similar to those reported for wood‐based particleboard when 80 wt % filler was used. The void content of the panels was experimentally determined and used in an attempt to predict the mechanical response of the panels. The stiffness of the particleboard could be greatly improved by a reduction of the porosity, but even a low void content had a critical effect on the strength of the composites. The stiffness of the composites could only be reasonably represented with simple theoretical models when the effect of the porosity was incorporated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 916–923, 2005
Characterization of 2‐(2‐methoxyethoxy)ethanol‐substituted phosphazene polymers using pervaporation, solubility parameters, and sorption studies
Authors: Orme Christopher J. , Klaehn John R. , Harrup Mason K. , Lash Robert P. , Stewart Frederick F.
Published: May 2005

Two linear phosphazene polymers were synthesized with differing amounts of hydrophilic 2‐(2‐methoxyethoxy)ethanol (MEE) and hydrophobic 4‐methoxyphenol (MEOP) substituted on the backbone. These high polymers were cast into membranes and their permeability to water, methanol, ethanol, and 2‐propanol was evaluated as a function of temperature. An additional polymer with a low content of MEE was studied for water permeation and was characterized by trace flux. At higher levels of MEE on the backbone, fluxes of all solvents increased. Solubility also was found to increase with increasing MEE content for all solvents except water. Unexpectedly, water was found to be less soluble in the higher MEE polymer, although higher membrane fluxes were observed. Diffusion coefficients showed the following trend: methanol ≫ 2‐propanol > ethanol ≫ water. Finally, the affinity of solvents and polymers was discussed in terms of Hansen solubility parameters. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 939–945, 2005
Tests for Differentiation in Gene Expression Using a Data‐Driven Order or Weights for Hypotheses
Authors: Hommel Gerhard , Kropf Siegfried
Published: May 2005

In the analysis of gene expression by microarrays there are usually few subjects, but high‐dimensional data. By means of techniques, such as the theory of spherical tests or with suitable permutation tests, it is possible to sort the endpoints or to give weights to them according to specific criteria determined by the data while controlling the multiple type I error rate. The procedures developed so far are based on a sequential analysis of weighted p ‐values (corresponding to the endpoints), including the most extreme situation of weighting leading to a complete order of p ‐values. When the data for the endpoints have approximately equal variances, these procedures show good power properties.

In this paper, we consider an alternative procedure, which is based on completely sorting the endpoints, but smoothed in the sense that some perturbations in the sequence of the p ‐values are allowed. The procedure is relatively easy to perform, but has high power under the same restrictions as for the weight‐based procedures. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Peptide hairpins with strand segments containing α‐ and β‐amino acid residues: Cross‐strand aromatic interactions of facing Phe residues
Authors: Roy Rituparna S. , Gopi Hosahudya N. , Raghothama S. , Gilardi Richard D. , Karle Isabella L , Balaram Padmanabhan
Published: May 2005

The incporation of β‐amino acid residues into the strand segments of designed β‐hairpin leads to the formation of polar sheets, since in the case of β‐peptide strands, all adjacent carbonyl groups point in one direction and the amide groups orient in the opposite direction. The conformational analysis of two designed peptide hairpins composed of α/β‐hybrid segments are described: Boc–Leu–βPhe–Val–D‐Pro–Gly–Leu–βPhe–Val–OMe (1) and Boc–βLeu–Phe–βVal–D‐Pro–Gly–βLeu–Phe–βVal–OMe (2). A 500‐MHz 1H‐NMR (nuclear magnetic resonance) analysis in methanol supports a significant population of hairpin conformations in both peptides. Diagnostic nuclear Overhauser effects (NOEs) are observed in both cases. X‐ray diffraction studies on single crystals of peptide 1 reveal a β‐hairpin conformation in both the molecules, which constitute the crystallographic asymmetric unit. Three cross‐strand hydrogen bonds and a nucleating type II′ β‐turn at the D‐Pro–Gly segment are observed in the two independent molecules. In peptide 1, the βPhe residues at positions 2 and 7 occur at the nonhydrogen‐bonding position, with the benzyl side chains pointing on opposite faces of the β‐sheet. The observed aromatic centroid‐to‐centroid distances are 8.92 Å (molecule A) and 8.94 Å (molecule B). In peptide 2, the aromatic rings must occupy facing positions in antiparallel strands, in the NMR‐derived structure.

Peptide 1 yields a normal “hairpin‐like” CD spectrum in methanol with a minimum at 224 nm. The CD spectrum of peptide 2 reveals a negative band at 234 nm and a positive band at 221 nm, suggestive of an exciton split doublet. Modeling of the facing Phe side chains at the hydrogen‐bonding position of a canonical β‐hairpin suggests that interring separation is ∼4.78 Å for the gauche+gauche− (g+g−) rotamer. A previously reported peptide β‐hairpin composed of only α‐amino acids, Boc–Leu–Phe–Val–D‐Pro–Gly–Leu–Phe–Val–OMe also exhibited an anomalous far‐UV (ultraviolet) CD (circular dichroism) spectrum, which was interpreted in terms of interactions between facing aromatic chromophores, Phe 2 and Phe 7 (C. Zhao, P. L. Polavarapu, C. Das, and P. Balaram, Journal of the American Chemical Society, 2000, Vol 122, pp. 8228–8231). © 2005 Wiley Periodicals, Inc. Biopoly 80: 787–799, 2005

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
(R)‐phenylacetylcarbinol production in aqueous/organic two‐phase systems using partially purified pyruvate decarboxylase from Candida utilis
Authors: Sandford Vanessa , Breuer Michael , Hauer Bernhard , Rogers Peter , Rosche Bettina
Published: May 2005

Aqueous/organic two‐phase systems have been evaluated for enhanced production of (R)‐phenylacetylcarbinol (PAC) from pyruvate and benzaldehyde using partially purified pyruvate decarboxylase (PDC) from Candida utilis. In a solvent screen, octanol was identified as the most suitable solvent for PAC production in the two‐phase system in comparison to butanol, pentanol, nonanol, hexane, heptane, octane, nonane, dodecane, methylcyclohexane, methyl tert butyl ether, and toluene. The high partitioning coefficient of the toxic substrate benzaldehyde in octanol allowed delivery of large amounts of benzaldehyde into the aqueous phase at a concentration less than 50 mM. PDC catalyzed the biotransformation of benzaldehyde and pyruvate to PAC in the aqueous phase, and continuous extraction of PAC and byproducts acetoin and acetaldehyde into the octanol phase further minimized enzyme inactivation, and inhibition due to acetaldehyde. For the rapidly stirred two‐phase system with a 1:1 phase ratio and 8.5 U/mL carboligase activity, 937 mM (141 g/L) PAC was produced in the octanol phase in 49 h with an additional 127 mM (19 g/L) in the aqueous phase. Similar concentrations of PAC could be produced in the slowly stirred phase separated system at this enzyme level, although at a much slower rate. However at lower enzyme concentration very high specific PAC production (128 mg PAC/U carboligase at 0.9 U/mL) was achieved in the phase separated system, while still reaching final PAC levels of 102 g/L in octanol and 13 g/L in the aqueous phase. By comparison with previously published data by our group for a benzaldehyde emulsion system without octanol (50 g/L PAC, 6 mg PAC/U carboligase), significantly higher PAC concentrations and specific PAC production can be achieved in an octanol/aqueous two‐phase system. © 2005 Wiley Periodicals, Inc.
Short‐term and long‐term effects of increasing temperatures on the stability and the production of volatile sulfur compounds in full‐scale thermophilic anaerobic digesters
Authors: Iranpour Reza , Cox Huub H.J. , Fan Steve , Abkian Varouj , Kearney Ray J. , Haug Roger T.
Published: May 2005

This study compares the effect of a rapid increase of the digester temperature (from 54°C to 58°C in 2 weeks) with a slow increase (from 53.9°C to 57.2°C at a rate of 0.55°C per month) on full‐scale thermophilic anaerobic digestion at Hyperion Treatment Plant. The short‐term test demonstrated that rapidly increasing the digester temperature caused elevated production of volatile sulfur compounds, most notably methyl mercaptan, but volatile solids destruction and methane production were not significantly affected. The increase of the volatile fatty acid to alkalinity ratio from 0.1 to over 0.3 indicated a transient change in digester biochemistry, which was reversed by lowering the temperature. In the long term‐test, a slow increase of digester temperature, the production of hydrogen sulfide increased above temperatures of 56.1°C, but was controlled by increased injection of ferrous chloride. Methyl mercaptan was detected in trace amounts at the highest temperature tested (57.2°C). This test showed insignificant effects on other digestion parameters, although some temperature‐independent changes were observed that could have been seasonal effects over the year that the long‐term test lasted. Thus a slow temperature increase was preferable. This observation contrasts with previous results showing the desirability of a rapid temperature rise to first establish a thermophilic culture when converting from mesophilic operation. Further research is warranted on temperature limits and process changes to optimize thermophilic anaerobic digestion. © 2005 Wiley Periodicals, Inc.
What citizens think about the police: assessing actual and wished‐for frequency of police activities in one's neighbourhood
Authors: Salmi Satu , Voeten Marinus , Keskinen Esko
Published: May 2005

The aim of the study was to find out what were citizens' assessments of actual and wished‐for frequencies of 12 police activities in two typical Finnish neighbourhoods. Data were collected from 3271 adults and 986 young people with a mail questionnaire. Actual and wished‐for frequencies were separately analysed using Homals. Both analyses produced a dimension indicating the assessed (actual or wished‐for) frequency of police work, disregarding the content of the 12 police activities. In addition, each analysis produced a dimension describing the tendency to give a ‘don't‐know’ answer. The latter two non‐substantive dimensions were interpreted as indicating that the general level of knowledge of police activities was not high among the citizens. When comparing the frequency assessments of ongoing police activities and the wishes concerning these activities, it was found that citizens wished the police to increase all cited activities, particularly foot patrolling, helping and supporting victims and giving crime prevention advice. Citizens appeared to be responsive to the activities related to community policing and preventive police work. All four dimensions were related with background characteristics of respondents (age, gender, city and living conditions), but these relations were not strong. Copyright © 2005 John Wiley & Sons, Ltd.
Young offenders, schools and the neighbourhood: a new approach to data‐analysis for community policing
Authors: Williamson Tom , Ashby David I. , Webber Richard
Published: May 2005

Youth offending often lies at the heart of community policing programmes. The primary objective of this study is to provide evidence of the extent to which the level and the pattern of youth offending varies between different types of neighbourhood and the schools they attend. We posit that the adoption of neighbourhood typology based analyses, frequently used in the commercial world, are appropriate to address this issue. We substantiate this argument with the analysis of a large anonymized database (c. 34,000 records spanning 5 years) containing the details of youth offenders and their offences in Nottinghamshire, segmented by neighbourhood type. The neighbourhood classification used, a proprietary geodemographic solution, is based on both census and consumer data, and segments all UK postcodes into 61 neighbourhood types and 11 aggregate groups. The results are analysed with reference to nine conditions: level of offending (total numbers of offences and offenders); single/repeat offenders; gender; ethnicity; offence classification; outcome; context (including temporal conditions such as school holidays); whether the offender accepted or denied occurrence; and age at the time of the occurrence.

Of particular interest is the association between the offenders and educational establishments, and thus the identification of schools that are most at risk for recidivism, raising questions regarding the concept of criminogenic schools. A number of policy recommendations are made which could lead to better informed strategy management in youth offending. We conclude that geodemographic analysis can leverage extra value and substantial insight from operational data bases collected on a routine basis. However, this poses the question as to why public sector practitioners and planners have not already made use of such analytical techniques, which have been central to much business strategy in recent years. This approach to the analysis of youth offender data lends itself to further social psychological research and exploration. Copyright © 2005 John Wiley & Sons, Ltd.
Why ‘soft’ policing is hard: on the curious development of reassurance policing, how it became neighbourhood policing and what this signifies about the politics of police reform
Authors: Innes Martin
Published: May 2005

Tracing the development of Reassurance Policing and its recent translation into Neighbourhood Policing, this article examines why it is that ‘soft’ policing functions appear so difficult for the police to perform. It is argued that over the past three decades the reform of policing in the UK has tended to oscillate between positions emphasizing coercive ‘hard’ policing functions and alternative conceptions that focus upon the conduct of soft policing, where the emphasis is upon a more persuasive mode of social control. Reassurance Policing is identified as important as, through its incorporation of aspects of the Signal Crimes Perspective, it provides a coherent logic that sets out why both hard and soft policing are important. It is concluded that future policing styles need to be able to respond to the diverse demands of the public and that this will require a combination of hard and soft policing. Copyright © 2005 John Wiley & Sons, Ltd.
Policing a complex community; political influence on policing and its impact on local and central accountability
Authors: Fletcher Robin
Published: May 2005

During the 1970s a series of events irrevocably changed the way in which policing was carried out in England and Wales. This paper describes how the police became politicized as it enforced government policies that resulted in violent police/public confrontation. It then explores how the Metropolitan Police Service began a process of re‐engagement with the highly complex society of London, by community‐focused policing models. The theoretical and practical difficulties of community policing are discussed in relation to legislation that required greater community involvement in policing. A theme of accountability is generated throughout the paper showing how political extremism challenged a bi‐partite system of police governance, unique to the Metropolitan Police in the context of the UK, by demanding local accountability. This resulted in conflicting legislation that promotes both localized and centralized forms of accountability. The paper concludes with a speculative theory of how policing may develop in London as a department of a local government. Copyright © 2005 John Wiley & Sons, Ltd.
Production of the Tubulin Destabilizer Disorazol in Sorangium cellulosum: Biosynthetic Machinery and Regulatory Genes
Authors: Kopp Maren , Irschik Herbert , Pradella Silke , Müller Rolf
Published: May 2005

Myxobacteria show a high potential for the production of natural compounds that exhibit a wide variety of antibiotic, antifungal, and cytotoxic activities.1, 2 The genus Sorangium is of special biotechnological interest because it produces almost half of the secondary metabolites isolated from these microorganisms. We describe a transposon‐mutagenesis approach to identifying the disorazol biosynthetic gene cluster in Sorangium cellulosum So ce12, a producer of multiple natural products. In addition to the highly effective disorazol‐type tubulin destabilizers,3–5 S. cellulosum So ce12 produces sorangicins, potent eubacterial RNA polymerase inhibitors,6 bactericidal sorangiolides, and the antifungal chivosazoles.7, 8 To obtain a transposon library of sufficient size suitable for the identification of the presumed biosynthetic gene clusters, an efficient transformation method was developed. We present here the first electroporation protocol for a strain of the genus Sorangium. The transposon library was screened for disorazol‐negative mutants. This approach led to the identification of the corresponding trans‐acyltransferase core biosynthetic gene cluster together with a region in the chromosome that is likely to be involved in disorazol biosynthesis. A third region in the genome harbors another gene that is presumed to be involved in the regulation of disorazol production. A detailed analysis of the biosynthetic and regulatory genes is presented in this paper.
Percutaneous implantation of an aortic valve prosthesis
Authors: Laborde J.C. , Borenstein N. , Behr L. , Farah B. , Fajadet J.
Published: May 2005

Recently, percutaneous aortic valve implantation has become an alternative technique to surgical valve replacement in patient at high risk for surgery. Our animal experimentation evaluated the technical feasibility of aortic valve replacement using a bovine pericardium valve sutured on a self‐expandable stent in a sheep model. Precise implantation with satisfactory attachment on the adjacent tissues and absence of migration was obtain in 8 out of 14 animals. This study confirmed the feasibility of the endovascular implantation of a pericardium valve sutured on a self‐expandable stent in a sheep model. © 2005 Wiley‐Liss, Inc.
Transradial stenting of the iliac artery: A case report
Authors: Flachskampf Frank A. , Wolf Tobias , Daniel Werner G. , Ludwig Josef
Published: May 2005

In this case report, stenting of the common iliac artery via the radial access route with 6 Fr equipment, including an extra long multipurpose catheter, is presented. Radial access avoids bleeding and ischemia that may complicate retrograde or crossover access to the iliac artery. © 2005 Wiley‐Liss, Inc.
Percutaneous occlusion of a pulmonary aneurysm causing hemoptysis in a patient with pulmonary atresia and aortopulmonary collaterals
Authors: Pate Gordon E. , Carere Ronald G.
Published: May 2005

A 28‐year‐old male was referred for cardiac catheterization because of recurrent severe hemoptysis necessitating resuscitation and subsequently preventing weaning from ventilation. He had a history of pulmonary atresia, ventricular septal defect, overriding aorta with right‐sided aortic arch diagnosed at birth. Eisenmenger's syndrome ensued and he was not felt to be suitable for corrective cardiac surgery. He had multiple major aortopulmonary collateral vessels to both lungs with a large aneurysm in an artery to the right lower lobe, which was suspected to be the source of his bleeding. Occlusion of this aneurysm was achieved percutaneously using an Amplatzer septal occluder device. He had no further bleeding and was successfully weaned from ventilation. Six months later, he has recovered to his functional baseline and has not had any further episodes of hemoptysis. © 2005 Wiley‐Liss, Inc.
Left ventricular unloading and concomitant total cardiac output increase by the use of percutaneous impella recover LP 2.5 assist device during high‐risk coronary intervention
Authors: Valgimigli Marco , Steendijk Paul , Sianos George , Onderwater Emile , Serruys Patrick W.
Published: May 2005

A number of techniques have been proposed for circulatory support during high‐risk percutaneous coronary interventions (PCI), but no single approach has achieved wide acceptance so far. We report on a patient with severe left ventricular (LV) impairment who underwent a PCI with the use of a new left ventricular assist device, the Impella Recover LP 2.5 system. The effects on global cardiac output were determined by thermodilution (TD) and LV pressure‐volume loops obtained by conductance catheter. The activation of the pump resulted in a rapid and sustained unloading effect of the LV. At the same time, the continuous expulsion of blood into ascending aorta throughout the cardiac cycle produced by the pump resulted in an increase of systemic overall CO, measured by the TD technique, of 1.43 L/min. The procedure was uncomplicated and the patient remained uneventful at follow‐up. Our single experience gives new input for future trials to assess the effect of the Impella Recover LP 2.5 assist device on outcome in this subset of patients. © 2005 Wiley‐Liss, Inc.
Molecular Aptamers for Real‐Time Protein–Protein Interaction Study
Authors: Cao Zehui , Tan Weihong
Published: May 2005

Protein–protein interactions play critical roles in cellular functions, but current techniques for real‐time study of these interactions are limited. We report the real‐time monitoring of protein–protein interactions without labeling either of the two interacting proteins; this procedure poses minimum effects on the binding properties of the proteins. Our strategy uses a protein/aptamer complex to probe the interactions in a competitive assay where the binding of an aptamer to its target protein is altered by a second protein that interacts with the target protein. Two signal transduction strategies, fluorescence resonance energy transfer (FRET) and fluorescence anisotropy, have been designed to study the interactions of human α‐thrombin with different proteins by using two aptamers specific for two binding sites on α‐thrombin. Our method has been shown to be simple and effective, does not require labeling of proteins, makes use of easily obtainable aptamers, provides detailed protein–protein interaction information and has excellent sensitivity for protein detection and protein–protein interaction studies. The FRET and the fluorescent anisotropy approaches complement each other in providing insight into the kinetics, mechanisms, binding sites and binding dynamics of the interacting proteins.
On the Regio‐ and Stereoselective Synthesis of Aminocyclitols from Cyclitol Epoxides: The Effect of Li as a Chelating Agent
Authors: Serrano Pedro , Llebaria Amadeu , Vázquez Jordi , de Pablo Joan , Anglada Josep M. , Delgado Antonio
Published: May 2005

Experimental and theoretical studies on the influence of Li ions on the regio‐ and the stereoselectivity of the reaction of cyclitol epoxides with nitrogen nucleophiles have been carried out. Model studies with NaN3as a nucleophile in the absence of Li ions predict a mixture of C1 and C2 regioadducts. The inclusion of two Li ions as a chelating agent favours the operation of a low populated “all‐axial” conformation leading ultimately to the C1 adducts. In all cases, the results can be rationalised by geometric and energetic considerations of the corresponding transition states. Predictions of the theoretical calculations are in good agreement with the experimental results using primary and secondary amines as nucleophiles, and thus confirm the validity of this study.
Substituent Effect To Prevent Autoxidation and Improve Spectral Stability in Blue Light‐Emitting Polyfluorenes
Authors: Li Jiu Yan , Ziegler Andreas , Wegner Gerhard
Published: May 2005

A group of fluorene‐based polymers, PF‐1SOR and PF‐2SOR, were synthesized and characterized as blue light‐emitting materials. PF‐1SOR and PF‐2SOR displayed nematic liquid crystalline mesophase in films cast from solution. Compared with conventional polyfluorene, PF‐1SOR and PF‐2SOR display blue‐shifted UV absorption and structureless blue fluorescence. The photoluminescence spectra of PF‐1SOR and PF‐2SOR were found insensitive against thermal treatment in air up to 200° C and the blue electroluminescence in their light‐emitting devices was independent of the driving voltage. Compared to the conventional polyfluorenes, the improved spectral stability of these polymers is attributed to the anti‐oxidization effect of (3,5‐di(tert‐butyl)phenoxy)sulfonyl side groups attached to the backbone.
Spatially Resolved Raman and UV‐visible‐NIR Spectroscopy on the Preparation of Supported Catalyst Bodies: Controlling the Formation of H2PMo11CoO405− Inside Al2O3 Pellets During Impregnation
Authors: Bergwerff Jaap A. , van de Water Leon G. A. , Visser Tom , de Peinder Peter , Leliveld Bob R. G. , de Jong Krijn P. , Weckhuysen Bert M.
Published: May 2005

The physicochemical processes that occur during the preparation of CoMo–Al2O3 hydrodesulfurization catalyst bodies have been investigated. To this end, the distribution of Mo and Co complexes, after impregnation of γ‐Al2O3 pellets with different CoMoP solutions (i.e., solutions containing Co, Mo, and phosphate), was monitored by Raman and UV‐visible‐NIR microspectroscopy. From the speciation of the different complexes over the catalyst bodies, insight was obtained into the interaction of the different components in the impregnation solution with the Al2O3 surface. It is shown that, after impregnation with a solution containing H2PMo11CoO405−, the reaction of phosphate with the Al2O3 leads to the disintegration of this complex. The consecutive independent transport of Co2+ complexes (fast) and Mo6+ complexes (slow) through the pores of the Al2O3 is envisaged. By the addition of extra phosphate and citrate to the impregnation solution, the formation of the desired heteropolyanion can be achieved inside the pellets. Ultimately, the H2PMo11CoO405− distribution could be controlled by varying the aging time applied after impregnation. The power of a combination of spatially resolved spectroscopic techniques to monitor the preparation of supported catalyst bodies is illustrated.
Synthesis and Characterization of Thermally Robust Amidinato Group 13 Hydride Complexes
Authors: Cole Marcus L. , Jones Cameron , Junk Peter C. , Kloth Marc , Stasch Andreas
Published: May 2005

The reactivity of two sterically bulky amidines, ArNC(R)N(H)Ar (Ar=2,6‐diisopropylphenyl; R=H (HFiso); tBu, (HPiso)) towards LiMH4, M=Al or Ga, [AlH3(NMe3)], and [GaH3(quin)] (quin=quinuclidine) has been examined. This has given rise to a variety of very thermally stable aluminum and gallium hydride complexes. The structural motif adopted by the prepared complexes has been found to be dependent upon both the amidinate ligand and the metal involved. The 1:1 reaction of HFiso with LiAlH4 yielded dimeric [{AlH3(μ‐Fiso)Li(OEt2)}2]. Amidine HFiso reacts in a 1:1 ratio with [AlH3(NMe3)] to give the unusual hydride‐bridging dimeric complex, [{AlH2(Fiso)}2], in which the Fiso− ligand is nonchelating. The equivalent reaction with the bulkier amidine, HPiso, yielded a related hydride‐bridging complex, [{AlH2(Piso)}2], in which the Piso− ligand is chelating. In contrast, the treatment of [GaH3(quin)] with one equivalent of HFiso afforded the four‐coordinate complex [GaH2(quin)(Fiso)], in which the Fiso− ligand acts as a localized monodentate amido–imine ligand. The 2:1 reactions of HFiso with [AlH3(NMe3)] or [GaH3(quin)] gave the monomeric complexes [MH(Fiso)2], which are thermally robust and which exhibit chelating amidinate ligands. In contrast, HPiso did not give 2:1 complexes in its reactions with either of the Group 13 trihydride precursors. For sake of comparison, the reactions of [AlH3(NMe3)] and [GaH3(quin)] with the bulky carbodiimide ArNCNAr and the thiourea Ar(H)NC(S)N(H)Ar were examined. These last reactions afforded the five‐coordinate thioureido complexes, [MH{N(Ar)C[N(H)(Ar)]S}2], M=Al or Ga.
Lack of benefit of spinal irradiation in the primary treatment of intracranial germinoma
Authors: Shikama Naoto , Ogawa Kazuhiko , Tanaka Shiro , Toita Takafumi , Nakamura Katsumasa , Uno Takashi , Ohnishi Hiroshi , Itami Jun , Tada Tsuyoshi , Saeki Naokatsu
Published: May 2005

BACKGROUND

The current study assessed the contribution of spinal irradiation to the treatment outcome of patients with intracranial germinoma.

METHODS

Clinical data from 180 patients with intracranial germinoma, who were treated with radiotherapy and/or chemotherapy from 1980 to 2001, were collected from 6 institutions. The patients' median age was 16 years (range, 1–47 yrs), and the male‐to‐female ratio was 133:47. Pathologic verification was obtained in 88 patients. A solitary tumor was seen in 129 patients, and multifocal or disseminated tumors were detected in 51 patients. The median tumor size was 2.5 cm (range, 0.6–7.0 cm). Local field and/or whole brain irradiation was performed in 114 patients, and craniospinal irradiation was performed in 66 patients. Fifty‐five patients were treated with chemotherapy. The median follow‐up time was 89 months (range, 3–297 mos).

RESULTS

Eight‐year overall and event‐free survival rates were 91% and 89%, respectively. The 8‐year recurrence rates at the primary site, intracranial space, and the spinal space were 1%, 6%, and 6%, respectively. Cox regression analysis showed that spinal irradiation (hazard ratio, 1.050; 95% confidence interval [CI], 0.355–3.170) did not contribute to a favorable event‐free survival.

CONCLUSIONS

Spinal irradiation did not contribute to favorable event‐free survival in patients with intracranial germinoma. Cancer 2005. © 2005 American Cancer Society.
Quantification of T‐cell–mediated apoptosis in heterogeneous leukemia populations using four‐color multiparameter flow cytometry
Authors: Westers Theresia M. , Houtenbos Ilse , Schuurhuis Gerrit Jan , Ossenkoppele Gert J. , van de Loosdrecht Arjan A.
Published: May 2005

Background

The unique capacity of dendritic cells to present antigens to naive T cells is being increasingly utilized in cancer therapy. The efficacy of cell‐based immunotherapy can be analyzed by determination of cytotoxic activity of T cells toward tumor cells in vitro. This study supplies a flow cytometric method to analyze T‐cell–mediated cytotoxic activity toward heterogeneous leukemic cell populations at a single‐cell level.

Methods

The fluorescent probe SYTO16 and the dead‐cell dye 7‐aminoactinomycine‐D (7‐AAD) were used to identify early and late stages of apoptosis in combination with leukemia cell‐identifying markers. Determination of viable, apoptotic, and necrotic cells was performed by inclusion of fluorescent beads.

Results

In nine acute myeloid leukemia samples and three leukemic cell lines the use of SYTO16 next to the dead‐cell marker 7‐AAD significantly increased (P = 0.001) the sensitivity of the cytotoxicity assay as compared with single use of 7‐AAD. Analysis of several effector‐to‐target ratios revealed the ability to determine dose‐response effects. Enumeration of absolute numbers resulted in coefficients of variation of 4.1% and 8.4% for cell lines and leukemic samples, respectively.

Conclusion

The presented flow cytometric cytotoxicity assay enables the study of T‐cell–mediated apoptosis in a heterogenous leukemia population. © 2005 Wiley‐Liss, Inc.
Expression profile of the RNA‐binding protein gene hermes during chicken embryonic development
Authors: Wilmore Helen P. , McClive Peter J. , Smith Craig A. , Sinclair Andrew H.
Published: May 2005

The hermes gene encodes an RNA‐binding protein containing an RNA‐recognition motif. Its expression has been described previously in Xenopus and in the developing heart of very young chicken embryos. We have analyzed the expression of cHermes in later heart development, where expression is maintained in the myocardium, and also in previously undescribed sites. cHermes expression first appears in the somites in the first terminally differentiated myocytes of both the epaxial and the hypaxial myotome. Expression is also seen in the primordium of the allantois and continues in the developing allantoic sac. cHermes expression in the pronephric and mesonephric kidneys coincides temporally and spatially with the appearance of the vascular components of the glomeruli. In addition, cHermes expression was seen in the mesoderm of the gut and in the notochord. Developmental Dynamics 233:1045–1051, 2005. © 2005 Wiley‐Liss, Inc.
Oxygen modifies artery differentiation and network morphogenesis in the retinal vasculature
Authors: Claxton Suzanne , Fruttiger Marcus
Published: May 2005

The mechanisms that control differentiation of immature blood vessels into either arteries or veins are not well understood. Because oxygen tension in arteries is higher than in veins, oxygen has the potential to be an instructive signal for artery/vein (AV) differentiation. We test this hypothesis by exposing newborn mice to moderate hypoxia (10% atmospheric oxygen) and studying AV differentiation in the developing retinal vasculature. Forming retinal arteries fail to express the artery‐specific markers Delta‐like 4 (Dll4) and EphrinB2 during hypoxia. However, other aspects of AV differentiation are retained such as high levels of alpha smooth muscle actin in arterial mural cells and vein‐specific expression of the msr/apj gene. The capillary network between arteries and veins is denser, and capillaries expressing the venous marker msr/apj are found in territories normally occupied by arterial capillaries. Thus, it appears that high oxygen in arterial blood is required for arterial expression of Dll4 and EphrinB2, which could be involved in cell–cell repulsion pathways that dictate the normal segregation of arteries and veins. Developmental Dynamics 233:822–828, 2005. © 2005 Wiley‐Liss, Inc.
Analysis of gene expression patterns in the developing chick liver
Authors: Yanai Masaaki , Tatsumi Norifumi , Endo Fumio , Yokouchi Yuji
Published: May 2005

The chick embryo has been used widely for studying liver development. However, in the past 30 years, the usage has decreased markedly due to lack of appropriate marker genes for differentiation in the developing chick liver. To use the chick embryo for analyzing the molecular mechanism of liver development, we surveyed marker genes in the developing chick liver by examining the expression pattern of genes that are well‐characterized in the developing mammalian liver. By whole‐mount in situ hybridization, Fibrinogen‐gamma (FIB) expression was first detected at stage 12, specifically in the anterior intestinal portal, and its liver‐specific expression persisted in the later stages. Albumin (ALB) expression was first detected at stage 30, when the liver starts maturing. Cytokeratin 19 (CK19) was first detected at stage 37 in the ductal plate of the liver, and its expression continued in the intrahepatic bile ducts derived from the ductal plate. Hex, a transcription factor, is an additional marker of bile duct differentiation. Hence, FIB, ALB, and CK19 expression can be used to trace hepatic induction, maturation, and bile duct differentiation, respectively. Developmental Dynamics 233:1116–1122, 2005. © 2005 Wiley‐Liss, Inc.
Transgenic zebrafish that express tyrosine hydroxylase promoter in inner retinal cells
Authors: Gao Yan , Li Ping , Li Lei
Published: May 2005

We have generated a transgenic zebrafish line [Tg(Th:GFP)] that expresses green fluorescence proteins (GFP) driven by rat tyrosine hydroxylase (TH) promoter. In zebrafish, the transgene was expressed as early as 16 hr postfertilization (hpf). The first transgene expression was detected in the midbrain. Within a few hours of development, the expression spread to the forebrain and hindbrain. In the retina, the first transgene expression was detected at approximately 40 hpf, at which time a single GFP‐positive cell was seen in the ventral–nasal patch of the retina. In late development, GFP spread across the inner retina. GFP was found in retinal cells that expressed TH or phenylethanolamine N‐methyl‐transferase (PNMT), the first and last enzymes for synthesis of catecholamine, respectively. This suggests that the transgene is expressed in catecholaminergic neurons. Of interest, GFP was also detected in some retinal cells that release γ‐aminobutyric acid. These latter data suggest that the transgene may also be expressed in noncatecholaminergic cells. Developmental Dynamics 233:921–929, 2005. © 2005 Wiley‐Liss, Inc.