bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cost comparison of genetic and clinical screening in families with hereditary hemorrhagic telangiectasia
Authors: Cohen Justine H. , Faughnan Marie E. , Letarte Michelle , Vandezande Kirk , Kennedy Shelley J. , Krahn Murray D. 
Published: July 2005

AbstractEndoglin (ENG) and ALK‐1 mutations cause hereditary hemorrhagic telangiecstasia (HHT), an autosomal dominant disorder leading to vascular dysplasia in the form of mucocutaneous telangiectasia and visceral arteriovenous malformations (AVMs). We proposed to compare two alternative strategies for management of HHT: screening HHT families with molecular diagnostic tests followed by targeted clinical screening versus conventional clinical screening. A decision analytic model was constructed to compare screening strategies for a hypothetical HHT family. The family consists of 1 index case and 13 relatives. The clinical screening protocol in use at the Canadian HHT Center in Toronto was assumed to be the standard of care. Unit costs for clinical screening (in Canadian dollars) were obtained from the 2003 Ontario Health Insurance Schedule of Benefits. Genetic screening costs were estimated for quantitative multiplex PCR and sequencing of Endoglin (ENG) and ALK‐1 genes, as performed at HHT Solutions, Toronto. The genetic screening strategy resulted in a net cost of $4,060 per individual versus $5,975 for the clinical screening strategy. The genetic screening strategy would save $1,915 per family member or $26,810 saved per family. Sensitivity analyses revealed that the genetic screening strategy was cost saving over all plausible ranges of input variables for all hypothetical families tested. We concluded that a genetic screening strategy with targeted clinical screening is more economically attractive than conventional clinical screening and results in a reduction in the number of clinical tests for family members who do not have HHT. © 2005 Wiley‐Liss, Inc.
A mitochondrial tRNA aspartate mutation causing isolated mitochondrial myopathy
Authors: Seneca Sara , Goemans Nathalie , Coster Rudy Van , Givron Patrice , Reybrouck Tony , Sciot Raf , Meulemans Ann , Smet Joel , Van Hove Johan L.K. 
Published: July 2005

AbstractSeveral mutations in mitochondrial transfer RNA (tRNA) genes can cause mitochondrial myopathy. We describe a young girl who presented with pronounced exercise intolerance. The anaerobic threshold and the maximal oxygen consumption were decreased. She had decreased complex I and IV enzyme activity and ragged red fibers on muscle biopsy. An A to G transition at nucleotide position 7526 in tRNA Aspartate (tRNAAsp) gene was heteroplasmic in several of the patient's tissues. We were unable to detect the mutation in muscle tissue from the patient's mother. This case adds a new genetic etiology for mitochondrial myopathy. It also illustrates for patients with combined deficiency of the complex I and IV enzyme activity the value of sequencing in the affected tissue muscle, and not only in blood, all mitochondrial tRNA genes including those not commonly affected, such as in this case mt tRNAAsp. © 2005 Wiley‐Liss, Inc.
Die Cucurbit[n]uril‐Familie
Authors: Lagona Jason , Mukhopadhyay Pritam , Chakrabarti Sriparna , Isaacs Lyle 
Published: July 2005

AbstractIm Jahre 1981 tauften Mock und Mitarbeiter das makrocyclische methylenverbrückte Glycoluril‐Hexamer (CB[6]) auf den Namen “Cucurbituril” – da ihre Form einem Kürbis ähnelt, dem bekanntesten Mitglied der Cucurbitaceae‐Familie in der Pflanzenwelt. In den folgenden Jahren wurden die grundlegenden Bindungseigenschaften von CB[6] – die hohe Affinität und Selektivität sowie der Einschluss von Gästen – in bahnbrechenden Arbeiten der Gruppen von Mock, Kim und Buschmann aufgezeigt; es folgten Anwendungen in der Wasseraufarbeitung, künstlichen Enzymen und molekularen Schaltern. Erst vor kurzem wuchs die Cucurbit[n]uril‐Familie um Homologe (CB[5]–CB[10]), Derivate, Verwandte und Analoga, sodass sie nun die Molekülgrößen von α‐, β‐ und γ‐Cyclodextrinen umfasst und übersteigt. Auch die Formen, Löslichkeiten und chemischen Funktionalitäten können inzwischen durch spezielle Synthesen den Erfordernissen angepasst werden. Durch diese Eigenschaften sind die Cucurbiturile prädestiniert für eine zentrale Rolle in molekularer Erkennung, Selbstorganisation und Nanotechnologie. Dieser Aufsatz stellt Synthesen, Erkennungseigenschaften und Anwendungen dieser einzigartigen Makrocyclen vor.
Barrier properties of paper–chitosan and paper–chitosan–carnauba wax films
Authors: Despond S. , Espuche E. , Cartier N. , Domard A. 
Published: July 2005

AbstractA gas barrier and biodegradable multilayer material was processed with a paper substrate, chitosan, and carnauba wax. The first step consisted of the study of the chitosan coating to obtain a dense polymer layer at the paper surface. The influence of the molecular weight and the concentration of the chitosan solution were studied, and a chitosan coating of 7 g/m2 was achieved, which led to interesting gas barrier properties in the anhydrous state. Nevertheless, the hydrophilic character of both cellulose and chitosan did not allow us to preserve these properties in the hydrated state. A layer of carnauba wax was then deposited on the chitosan face of the bilayer. Because of the hydrophobic character of this external layer, the water sorption in the multilayer decreased greatly, and CO2 and O2 permeability coefficients lower than 0.5 barrer were obtained in the hydrated state. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 704–710, 2005
Solid‐state compaction and drawing of nascent reactor powders of ultra‐high‐molecular‐weight polyethylene
Authors: Joo Yong Lak , Zhou Huajun , Lee Seung‐Goo , Lee Hwan‐Koo , Song Jae Kyung 
Published: July 2005

AbstractThe continuous production of ultra‐high‐molecular‐weight polyethylene (UHMWPE) filaments was studied by the direct roll forming of nascent reactor powders followed by subsequent multistage orientation drawing below their melting points. The UHMWPE reactor powders used in this study were prepared by the polymerization of ethylene in the presence of soluble magnesium complexes, and they exhibited high yield even at low reaction temperatures. The unique, microporous powder morphology contributed to the successful compaction of the UHMWPE powders into coherent tapes below their melting temperatures. The small‐angle X‐ray scattering study of the compacted tapes revealed that folded‐chain crystals with a relatively long‐range order were formed during the compaction and were transformed into extended‐chain crystals as the draw ratio increased. Our results also reveal that the drawability and tensile and thermal properties of the filaments depended sensitively on both the polymerization and solid‐state processing conditions. The fiber drawn to a total draw ratio of 90 in the study had a tensile strength of 2.5 GPa and a tensile modulus of 130 GPa. Finally, the solid‐state drawn UHMWPE filaments were treated with O2 plasma, and the enhancement of the interfacial shear strength by the surface treatment is presented. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 718–730, 2005
Application of polymer gels containing side‐chain phosphate groups to drug‐delivery contact lenses
Authors: Sato Takao , Uchida Rei , Tanigawa Haruyasu , Uno Kenji , Murakami Akira 
Published: July 2005

AbstractHydrogels that contain phosphate groups in side chains were studied for their usefulness in drug‐delivery soft contact lenses (SCLs). Naphazoline, a model drug having a cationic group, was incorporated into an SCL because of its phosphate groups and was released over a period of about 14 h. For the SCL, the naphazoline content was equivalent to the phosphate group content. It is suggested that drug‐delivery SCLs can be designed to contain the needed amount of a drug through the choice of the ionic group for the ligand. Furthermore, the SCL having amide groups and phosphate groups had high transparency and an unchanged shape. It is suggested that amide groups and phosphate groups must be introduced into the polymer in equimolar amounts to give the necessary polymer–drug interaction. Therefore, hydrogels having a drug‐delivery system were synthesized by the inclusion of a phosphate group and an amide group. These hydrogels are also applicable to SCL materials. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 731–735, 2005
Analysis of the crosslinking process of epoxy–phenolic mixtures by thermal scanning rheometry
Authors: Laza J. M. , Vilas J. L. , Mijangos F. , Rodríguez M. , León L. M. 
Published: July 2005

AbstractThe curing reaction of different mixtures of an epoxy resin (diglycidyl ether of bisphenol A type) and a phenolic resin (resole type) cured with different amine concentrations (triethylene tetramine) was studied with thermal scanning rheometry under isothermal conditions from 30 to 95°C. The gel time, defined by several criteria, was used to determine the apparent activation energy of the process. Moreover, with an empirical model used to predict the change in the complex viscosity versus time until the gel time was reached, and under the assumption of first‐order kinetics, the apparent rate constant and the apparent activation energy for the curing process were calculated. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 818–824, 2005
Reduced shrinkage polyester–montmorillonite nanocomposite
Authors: Al‐Khanbashi Abdullah , El‐Gamal Maisa , Moet Abdelsamie 
Published: July 2005

AbstractA new approach is described for utilizing the swelling characteristics of montmorillonite (MMT) to compensate for polymerization‐induced shrinkage in unsaturated polyester. The naturally sorbed sodium cation, at the lamellar interface of the mineral, was exchanged with the onium salt of 12‐aminolauric acid to produce organophilic MMT, which was compatible with the host resin. The latter, boosted by a small amount of dimethylformamide, swelled into a polymerizing polyester resin, thus reducing polymerization shrinkage. The incorporation of 5% 12‐aminolauric MMT caused the shrinkage of the neat isophthalic polyester resin to be reduced from 8.7 to 2.6%. Wide‐angle X‐ray diffraction and high resolution scanning electron microscopy analyses showed that the shrinkage reduction was associated with increased interparticle spacing and uniform dispersion of the MMT domains on the nanoscale. Mechanical measurements indicated that the flexural strength of the new compound was comparable to that of the neat resin; however, a remarkable 100% increase in toughness was observed in association with a minor decrease in the modulus of elasticity. This increased toughness may be attributed to macromolecular changes associated with the monofunctional acid moiety of the 12‐aminolauric acid. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 767–773, 2005
Adhesion of microwave‐plasma‐treated fluoropolymers to thermoset vinylester
Authors: Hedenqvist M. S. , Merveille A. , Odelius K. , Albertsson A.‐C. , Bergman G. 
Published: July 2005

AbstractPoly(tetrafluoroethylene) and a fluoroethylene copolymer were surface treated with a 2.45‐GHz microwave plasma to enhance their adhesion to a vinylester thermoset. The plasmas were generated with an inert gas (Ar) and with reactive gases (H2, O2, and N2). The lap‐joint shear stress was measured on fluoropolymer samples glued with the vinylester. In general, the stress at failure increased with increasing plasma‐energy dose. The H2 plasma yielded the best adhesion, and X‐ray photoelectron spectroscopy revealed that it yielded the highest degree of defluorination of the fluoropolymer surface. The defluorination efficiency declined in the order H2, Ar, O2, and N2. Contact angle measurements and scanning electron microscopy revealed that the surface roughness of the fluoropolymer depended on the rate of achieving the target energy dose. High power led to a smoother surface, probably because of a greater increase in temperature and partial melting. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 838–842, 2005
Morphology control of hollow polymer latex particle preparation
Authors: He Xiao‐Dong , Ge Xue‐Wu , Wang Mo‐Zhen , Zhang Zhi‐Cheng 
Published: July 2005

AbstractHollow polymer latex particles containing a hydrophilic core fully encapsulated with a hydrophobic shell were prepared by multistage polymerization followed by neutralization with a base. The diameters of the particles were monodispersed and void fractions of the prepared latex particles as high as 50% were achieved. High instantaneous monomer conversion was found to be the key point to minimize the interdiffusion of the core–shell polymer chains. The influences of the shell crosslinking agent and shell carboxyl content on the hollow morphology were also investigated. The maximum hollow diameter was observed with crosslinking agent contents of 7.5–12.5 wt %. The shell carboxyl content had an appropriate value, and an excess of it resulted in an excentric hollow structure. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 860–863, 2005
Supercritical CO2‐assisted synthesis of poly(acrylic acid)/Antheraea pernyi SF blend
Authors: Peng Qi , Xu Qun , Xu Hongyan , Pang Maizhi , Li Jianbo , Sun Dengfeng 
Published: July 2005

AbstractMonomer acrylic acid (AA) and initiator azo‐bis(isobutyronitrile)were carried into Antheraea pernyi silk fibroin (SF) fibers using supercritical CO2 as a solvent and carrier, followed by free radical polymerization at a suitable temperature, resulting in PAA/SF blends. The binary system of CO2/AA and the ternary system of CO2/AA/AIBN systems were studied. Different impregnation conditions, such as time, pressure, and concentration of AA in the fluid phase on mass uptake, were studied. Fourier transform infrared spectroscopy and X‐ray diffraction results confirmed that PAA was indeed present in the silk and that there were intermolecular hydrogen bonds between PAA and SF. According to thermogravimetry and DTG, blending with PAA could enhance the thermal stability of SF slightly. The water retention values indicated that the hydrophilic nature of the fibers was improved. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 864–868, 2005
Assessing the predictive capability of two‐phase models for the mechanical behavior of alumina/epoxy nanocomposites
Authors: Brown G. M. , Ellyin F. 
Published: July 2005

AbstractA review of analytical modeling of particulate reinforcement is made as a prelude to the problem of microstructural inhomogeneity in nanocomposite materials. Noting the inevitability of dispersion nonuniformity, and variations in agglomerate morphology and filler‐matrix interaction, the need to question the application of such models to novel materials arises. Employing the mechanical properties of alumina/epoxy nanocomposites, with known dispersion characteristics, an evaluation of the predictive capability of various models for Young's modulus, strength, and failure strain is made. Comparison between models is accompanied by a discussion of the parameters used in the fitting of macroscopic behavior to microstructural features. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 869–879, 2005
Developments in Astrophysics
Authors: Wolfschmidt Gudrun , Kiefer Claus 
Published: July 2005

AbstractJ01 The Understanding of Michelson's Experiment – Paving the Way for Einstein?J02 Albert Einstein's book suggestionJ03 New research on the discovery of the field equations of the general relativity by David Hilbert and Albert EinsteinJ04 Three cosmological dogmas – Einsteins influence on early relativistic cosmologyJ05 Testing Einstein's General Theory of RelativityJ06 Critical remarks on Bruno Thüring's polemic against EinsteinJ07 Einstein and the Gravitational WavesJ08 Computer‐aided Control Systems in Astrophysical Techniques – Development in the Second Half of the Past CenturyJ09 The Treasure from the Attic – Letters from Einstein, Planck, Born, Nernst, Debye, Sommerfeld, Courant, Weyl, Ehrenfest and Althoff to David Hilbert discovered in an Attic in GöttingenJ10 Biographical sources for 20th century astronomers and astrophysicistsJ11 The Rising of Canopus, the Septuagint, and The Encounter Between Shimon the Just and Antiochus the GreatJ12 History of One Defeat: Reform of the Julian Calendar as Envisioned by Isaac Newton
Stereospecific Synthesis of Chiral 2,3‐Dihydro‐1,4‐benzodithiine and Methyl‐2,3‐dihydro‐1,4‐benzodithiine Derivatives and their Toxic Effects on Trypanosoma brucei
Authors: Ali Shah Syed Tasadaque , Merkel Patrick , Ragge Hubert , Duszenko Michael , Rademann Jörg , Voelter Wolfgang 
Published: July 2005

AbstractPreparation of chiral 2,3‐dihydro‐1,4‐benzodithiine and methyl‐2,3‐dihydro‐1,4‐benzodithiine derivatives with known absolute configurations from the easily accessible chiral synthons benzyl 4‐O‐trifloxy‐2,3‐anhydro‐β‐L‐ribopyranoside and benzyl 4‐O‐trifloxy‐2,3‐anhydro‐α‐D‐ribopyranoside is described. These compounds showed significant in vitro toxicity of the bloodstream form of Trypanosoma brucei with an IC50 of 11 μM. The parasites' energy metabolism and consumption of oxygen were found to be affected during incubation.
Chiral Interactions in Azobenzene Dimers: A Combined Experimental and Theoretical Study
Authors: Painelli Anna , Terenziani Francesca , Angiolini Luigi , Benelli Tiziana , Giorgini Loris 
Published: July 2005

AbstractTo investigate interchromophore interactions in azobenzene polymers, we have undertaken a thorough spectroscopic analysis of the azodye [(S)‐3‐pivaloyloxy‐1‐(4′‐nitro‐4‐azobenzene)pyrrolidine] by modeling the repeating unit of poly[(S)‐3‐methacryloyloxy‐1‐(4′‐nitro‐4‐azobenzene)pyrrolidine) and its dimeric derivative whose synthesis is presented here. The analysis of the electronic and Raman spectra of the azodye in several solvents is based on a previously proposed model for polar chromophores in solution. Electronic and CD spectra of the dimeric unit are collected and analyzed within the framework of a new model. On the basis of the information collected from the spectroscopic analysis of the solvated dye, this model accounts for interchromophore interactions in the dimer. The large CD signal measured for the dimer (amounting to about a third of the signal measured for the polymer) suggests the presence of important chiral interactions in the dimeric unit, and is modeled in terms of a right‐handed relative orientation of the two chromophores.
Characterization of the Monovalent Ion Position and Hydrogen‐Bond Network in Guanine Quartets by DFT Calculations of NMR Parameters
Authors: van Mourik Tanja , Dingley Andrew J. 
Published: July 2005

AbstractConformational stability of G‐quartets found in telomeric DNA quadruplex structures requires the coordination of monovalent ions. Here, an extensive Hartree–Fock and density functional theory analysis of the energetically favored position of Li+, Na+, and K+ ions is presented. The calculations show that at quartet–quartet distances observed in DNA quadruplex structures (3.3 Å), the Li+ and Na+ ions favor positions of 0.55 and 0.95 Å outside the plane of the G‐quartet, respectively. The larger K+ ion prefers a central position between successive G‐quartets. The energy barrier separating the minima in the quartet‐ion‐quartet model are much smaller for the Li+ and Na+ ions compared with the K+ ion; this suggests that K+ ions will not move as freely through the central channel of the DNA quadruplex. Spin–spin coupling constants and isotropic chemical shifts in G‐quartets extracted from crystal structures of K+‐ and Na+‐coordinated DNA quadruplexes were calculated with B3LYP/6‐311G(d). The results show that the sizes of the trans‐hydrogen‐bond couplings are influenced primarily by the hydrogen bond geometry and only slightly by the presence of the ion. The calculations show that the RN2N7 distance of the N2‐H2⋅⋅⋅N7 hydrogen bond is characterized by strong correlations to both the chemical shifts of the donor group atoms and the h2JN2N7 couplings. In contrast, weaker correlations between the h3JN1C6′ couplings and single geometric factors related to the N1‐H1⋅⋅⋅O6C6 hydrogen bond are observed. As such, deriving geometric information on the hydrogen bond through the use of trans‐hydrogen‐bond couplings and chemical shifts is more complex for the N1‐H1⋅⋅⋅O6C6 hydrogen bond than for the N2‐H2⋅⋅⋅N7 moiety. The computed trans‐hydrogen‐bond couplings are shown to correlate with the experimentally determined couplings. However, the experimental values do not show such strong geometric dependencies.
The Chemical Bond in Polyphosphides: Crystal Structures, the Electron Localization Function, and a New View of Aromaticity in P42− and P5−
Authors: Kraus Florian , Korber Nikolaus 
Published: July 2005

AbstractThe incongruent solvation of MI4P6 species (MI = K, Rb, Cs) in liquid ammonia leads to a broad variety of polyphosphides such as P73−, P113−, and the putatively aromatic P42− and P5−, which we investigated by using NMR spectroscopy and single‐crystal X‐ray structure analysis. The structures of Cs2P4⋅2 NH3, (K@[18]crown‐6)3K3(P7)2⋅10 NH3, Rb3P7⋅7 NH3, and (Rb@[18]crown‐6)3P7⋅6 NH3 are discussed and compared. The electron localization function ELF is used in a comparison of the chemical bonding of various phosphorus species. The variances of the basin populations provide a well‐established measure for electron delocalization and therefore aromaticity. While comparable variance is calculated for P42− and P5− it is observed in the lone pairs rather than in the basin populations of the bonds as in the prototypical aromatic hydrocarbons such as benzene or the cyclopentadienide anion. For this behavior, the term “lone pair aromaticity” is proposed.
Reactivity of Alkynes Containing α‐Hydrogen Atoms with a Triruthenium Hydrido Carbonyl Cluster: Alkenyl versus Allyl Cluster Derivatives
Authors: Cabeza Javier A. , del Río Ignacio , García‐Granda Santiago , Martínez‐Méndez Lorena , Pérez‐Carreño Enrique 
Published: July 2005

AbstractThe reactions of the hydrido–triruthenium cluster complex [Ru3(μ‐H)(μ3‐κ2‐HNNMe2)(CO)9] (1; H2NNMe2=1,1‐dimethylhydrazine) with alkynes that have α‐hydrogen atoms give trinuclear derivatives containing edge‐bridging allyl or face‐capping alkenyl ligands. Under mild conditions (THF, 70 °C) the isolated products are as follows: [Ru3(μ3‐κ2‐HNNMe2)(μ‐κ3‐1‐syn‐Me‐3‐anti‐EtC3H3)(μ‐CO)2(CO)6] (2) and [Ru3(μ3‐κ2‐HNNMe2)(μ‐κ3‐1‐syn‐Me‐3‐syn‐EtC3H3)(μ‐CO)2(CO)6] (3) from 3‐hexyne; [Ru3(μ3‐κ2‐HNNMe2)(μ‐κ3‐3‐anti‐PhC3H4)(μ‐CO)2(CO)6] (4), [Ru3(μ3‐κ2‐HNNMe2)(μ‐κ2‐MeCCHPh)(μ‐CO)2(CO)6] (5) and [Ru3(μ3‐κ2‐HNNMe2)(μ3‐κ2‐PhCCHMe)(μ‐CO)2(CO)6] (6) from 1‐phenyl‐1‐propyne; [Ru3(μ3‐κ2‐HNNMe2)(μ‐κ2‐3‐anti‐PrC3H4)(μ‐CO)2(CO)6] (7), [Ru3(μ3‐κ2‐HNNMe2)(μ3‐κ2‐BuCCH2)(μ‐CO)2(CO)6] (8), and [Ru3(μ3‐κ2‐HNNMe2)(μ3‐κ2‐HCCHBu)(μ‐CO)2(CO)6] (9) from 1‐hexyne; [Ru3(μ3‐κ2‐HNNMe2)(μ3‐κ2‐HOH2CCCH2)(μ‐CO)2(CO)6] (10) from propargyl alcohol; and [Ru3(μ3‐κ2‐HNNMe2)(μ3‐κ2‐MeOCH2CCH2)(μ‐CO)2(CO)6] (11) from 3‐methoxy‐1‐propyne. The regioselectivity of these reactions depends upon the nature of the alkyne reagent, which affects considerably the kinetic barriers of important reaction steps and the stability of the final products. It has been established that the face‐capped alkenyl derivatives are not precursors to the allyl products, which are formed via edge‐bridged alkenyl intermediates. At higher temperature (toluene, 110 °C), the complexes that have allyl ligands with an anti substituent are isomerized into allyl derivatives with that substituent in the syn position, for example, 4 into [Ru3(μ3‐κ2‐HNNMe2)(μ‐κ3‐3‐syn‐PhC3H4)(μ‐CO)2(CO)6] (14). The diene complex [Ru3(μ‐H)(μ3‐κ2‐HNNMe2)(μ‐κ4‐trans‐EtC4H5)(CO)7] (13) has been obtained from the thermolysis of compounds 2 and 7 at 110 °C (3 and [Ru3(μ3‐κ2‐HNNMe2)(μ‐κ2‐3‐syn‐PrC3H4)(μ‐CO)2(CO)6] (12) are also formed in these reactions). A DFT theoretical study has allowed a comparison of the thermodynamic stabilities of isomeric compounds and has helped rationalize the experimental results. Mechanistic proposals for the synthesis of the allyl complexes and their isomerization processes are also provided.