bluuebunny/crossref_metadata_2025 huggingface dataset:
COL6A1 genomic deletions in Bethlem myopathy and Ullrich muscular dystrophy
Authors: Pepe Guglielmina , Lucarini Laura , Zhang Rui‐Zhu , Pan Te‐Cheng , Giusti Betti , Quijano‐Roy Susana , Gartioux Corine , Bushby Katharine M. D. , Guicheney Pascale , Chu Mon‐Li
Published: November 2005

We have identified highly similar heterozygous COL6A1 genomic deletions, spanning from intron 8 to exon 13 or intron 13, in two patients with Ullrich congenital muscular dystrophy and the milder Bethlem myopathy. The 5′ breakpoints of both deletions are located within a minisatellite in intron 8. The mutations cause in‐frame deletions of 66 and 84 amino acids in the amino terminus of the triple‐helical domain, leading to intracellular accumulation of mutant polypeptides and reduced extracellular collagen VI microfibrils. Our studies identify a deletion‐prone region in COL6A1 and suggest that similar mutations can lead to congenital muscle disorders of different clinical severity. Ann Neurol 2005
Pyruvate carboxylase deficiency: Metabolic characteristics and new neurological aspects
Authors: García‐Cazorla Angels , Rabier Daniel , Touati Guy , Chadefaux‐Vekemans Bernadette , Marsac Cécile , de Lonlay Pascale , Saudubray Jean‐Marie
Published: November 2005

Objective

Pyruvate carboxylase (PC) deficiency is a rare metabolic disease. Recently, therapeutic possibilities have been introduced. We aimed to report the largest series of the B type of PC deficiency, focusing on some neurological aspects that have not yet been documented.

Methods

We retrospectively studied nine patients with the severe neonatal form of PC deficiency diagnosed in our hospital. Detailed clinical features, brain imaging, biochemical characteristics, and global outcome are reported.

Results

All patients had axial hypotonia and tachypnea during the first hours of life. The initial level of consciousness was preserved in most patients. Abnormal movements (high‐amplitude tremor and hypokinesia) and bizarre ocular behavior were the most common findings, whereas epilepsy was infrequent. Brain magnetic resonance imaging mostly disclosed cystic periventricular leukomalacia. Hypoglycemia, lactic acidosis, and hypercitrullinemia were invariably found. Hyperammoniemia, hypernatremia, and high proline and lysine were frequently detected. A rapid fatal outcome was observed in most patients.

Interpretation

Clinical and biochemical characteristics of this deficiency are highly suggestive. Abnormal movements such as rigidity and hypokinesia (hypokinetic‐rigid syndrome) are an important hallmark and may orientate to PC deficiency when associated with severe lactic acidosis. Ann Neurol 2005
Lipoprotein‐associated phospholipase A2 is associated with risk of dementia
Authors: van Oijen Marieke , van der Meer Irene M. , Hofman Albert , Witteman Jacqueline C. M. , Koudstaal Peter J. , Breteler Monique M. B.
Published: November 2005

Objective

High levels of the inflammatory marker lipoprotein‐associated phospholipase A2 (Lp‐PLA2) have been proposed to be a predictor of coronary heart disease and stroke. Because both inflammation and vascular disease are associated with dementia, the objective of the present study was to examine the association between Lp‐PLA2 and the risk of dementia.

Methods

Within the Rotterdam Study, a population‐based prospective cohort study, we performed a case–cohort study. Of the 6,713 participants at risk for dementia, a random sample of 1,742 individuals was drawn. During follow‐up (mean, 5.7 years), 302 incident dementia cases were identified. Cox proportional hazard models were used to estimate the association of Lp‐PLA2 and dementia.

Results

We found that subjects with higher levels of Lp‐PLA2 had an increased risk of dementia. Compared with the first quartile of Lp‐PLA2, age‐ and sex‐adjusted hazard ratios (HRs; 95% confidence interval [CI]) for dementia for the second, third, and fourth quartiles were 1.19 (0.78–1.81), 1.15 (0.74–1.79), and 1.56 (1.03–2.37), respectively (p value for trend 0.04). Additional adjustment for cardiovascular and inflammatory factors did not change the estimates.

Interpretation

This is the first study to our knowledge that shows that Lp‐PLA2 is associated with the risk of dementia independent of cardiovascular and inflammatory factors and provides evidence for a potential role of Lp‐PLA2 in identifying subjects at risk for dementia. Ann Neurol 2006
1,4‐Wanderung von Rhodium und Palladium bei metallorganischen Katalysereaktionen
Authors: Ma Shengming , Gu Zhenhua
Published: November 2005

Mechanismen, die auf der 1,4‐Wanderung von Metallzentren beruhen, sind zur Erklärung einiger interessanter Übergangsmetall‐katalysierter Umsetzungen herangezogen worden. Trotz der nur wenigen belastbaren Belege lässt sich postulieren, dass die 1,4‐Metallwanderung über die reduktive Eliminierung von dreifach gebundenen Intermediaten bei Rhodium‐katalysierten Umsetzungen sowie von vierfach gebundenen Intermediaten bei Palladium‐katalysierten Prozessen abläuft. Diese hochvalenten metallorganischen Spezies sollten sich durch oxidative Addition an die C‐H‐ und C‐X‐Bindungen bilden. Dieser Kurzaufsatz fasst die Ergebnisse auf diesem Gebiet zusammen.
Weiche Nanotechnologie mit weichen Nanopartikeln
Authors: Nayak Satish , Lyon L. Andrew
Published: November 2005

Die materialwissenschaftliche Forschung der letzten zehn Jahre hat sich in steigendem Maße der Untersuchung nanoskaliger Materialien zugewendet. Heute sind die Nanowissenschaften ein multidisziplinäres Fach, und ein grundlegendes Verständnis von optischen, elektrischen, magnetischen und mechanischen Eigenschaften von Nanostrukturen stellt die Entwicklung neuer funktionaler Materialien für eine Vielzahl von Anwendungen in Aussicht. Die Bandbreite ist extrem groß, und viele Arbeiten konzentrieren sich auf “harte” Materialien wie Fullerene, Kohlenstoff‐Nanoröhren, Metalle, Halbleiter und organische oder anorganische Dielektrika. Hinzugekommen sind zwischenzeitlich auch weiche Materialien, vor allem leitende oder emittierende Polymere für Elektronikanwendungen auf Kunststoffbasis (“Plastic Electronics”). Das Interesse an diesem etablierten Gebiet der Nanotechnologie hält weiterhin an, darüber hinaus werden aber auch zunehmend neue Klassen von weichen Nanomaterialien aus konventionellen Polymerstrukturen entwickelt. Insbesondere erscheinen nanostrukturierte Hydrogele als vielversprechende Materialien für vielfältige Anwendungen in der Biotechnologie, und der Bedarf an hochentwickelten Materialien wird in der Postgenom‐Ära weiter steigen. Dieser Aufsatz beschreibt einige der neuesten Fortschritte bei der Anwendung quellbarer Gelnetzwerke in der Nanotechnologie.
Titelbild: Molecular Wires from Contorted Aromatic Compounds (Angew. Chem. 45/2005)
Authors: Xiao Shengxiong , Myers Matthew , Miao Qian , Sanaur Sébastien , Pang Keliang , Steigerwald Michael L. , Nuckolls Colin
Published: November 2005

Nichtplanare aromatische Kerne werden für das Design molekülbasierter elektronischer Materialien genutzt. C. Nuckolls et al. diskutieren in ihrer Zuschrift auf S. 7556 ff. die Herstellung von Materialien, die sich wegen der hohen Ladungsträgerbeweglichkeit, der niedrigen Einschaltspannung und des hohen An/Aus‐Stromverhältnisses als aktive Schicht in Feldeffekttransistoren eignen. Das Titelbild zeigt die Molekülstruktur einer neuen Klasse von Hexabenzocoronenen mit stark aus der Planarität verzerrter Struktur.
1,4‐Migration of Rhodium and Palladium in Catalytic Organometallic Reactions
Authors: Ma Shengming , Gu Zhenhua
Published: November 2005

Mechanisms based on the 1,4‐migration of metal centers have been proposed to explain some interesting transition‐metal‐catalyzed organic transformations. Despite the lack of solid evidence for the real nature of this process, the 1,4‐metal migration reaction is proposed to proceed by the reductive elimination of trivalent intermediates for the Rh‐involved reactions and of tetravalent intermediates for the Pd‐catalyzed processes. These high‐valent organometallic species would be formed by the oxidative addition to CH and CX bonds. This minireview summarizes the results in this area.
Reactions in Micellar Systems
Authors: Dwars Torsten , Paetzold Eckhard , Oehme Günther
Published: November 2005

The notion of “green chemistry” has encouraged even synthetic organic chemists to include water as a solvent. Incredible selectivities and activities can be achieved through the addition of amphiphiles with a defined structure. The morphology of supramolecular assemblies or associates formed by surfactants vary according to the temperature and concentration. As a rule, reactions are typically conducted using simple spherical aggregates, that is, micelles in the nanometer range. The strong polarity gradient present between the hydrophilic surface and the hydrophobic core of the micelle means that both nonpolar and polar reagents can be solubilized. This solubilization results in reactants becoming more concentrated within the micelle than in the surrounding water phase and leads to an acceleration of the reaction and causes selective effects. The kinetic treatment of reactions in micellar systems can be accomplished by considering them as microheterogeneous two‐phase systems.
Cover Picture: Molecular Wires from Contorted Aromatic Compounds (Angew. Chem. Int. Ed. 45/2005)
Authors: Xiao Shengxiong , Myers Matthew , Miao Qian , Sanaur Sébastien , Pang Keliang , Steigerwald Michael L. , Nuckolls Colin
Published: November 2005

Nonplanar aromatic cores are used for the design of molecule‐based electronic materials. In their Communication on page 7390 ff., C. Nuckolls and co‐workers discuss the preparation of materials that can be applied to field‐effect transistors as an active layer owing to their high carrier mobilities, low turn‐on voltages, and high on/off current ratios. The cover picture shows the molecular structure of a new class of hexabenzocoronenes in which the core is severely distorted out of planarity.
Organometallic compounds with biologically active molecules: in vitro antibacterial and antifungal activity of some 1,1′‐(dicarbohydrazono) ferrocenes and their cobalt(II), copper(II), nickel(II) and zinc(II) complexes
Authors: Chohan Zahid H. , Supuran Claudiu T.
Published: November 2005

Some 1,1′‐(dicarbohydrazono) ferrocenes have been prepared by condensing 1,1′‐diacetylferrocene with either 2‐furoic hydrazide, 2‐thiophenecarboxylic hydrazide or 2‐salicylic hydrazide. All the ligands synthesized were characterized by IR and NMR spectroscopy and elemental analysis data (carbon, hydrogen, nitrogen) and then were used as ligands to react with cobalt(II), copper(II), nickel(II) and zinc(II) metals as chlorides to afford metal complexes having the general formula M(L)Cl2. IR and electronic spectral data, magnetic moment and elemental analyses were used in the structural investigation of the metal complexes synthesized. The ligands synthesized and their metal(II) complexes have been screened for their in vitro antibacterial activity against Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysenteriae, Bacillus cereus, Corynebacterium diphtheriae, Staphylococcus aureus and Streptococcus pyogenes bacterial strains and for in vitro antifungal activity against Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani and Candida glabrata. The results of these studies show the metal complexes to be more antibacterial and antifungal than the uncomplexed ligands. However, the potency of all the ligands synthesized and their metal complexes was lower than that of the standard drugs. Copyright © 2005 John Wiley & Sons, Ltd.
New preparation of gold–silver complexes and optical fibre environmental sensors based on vapochromic [Au2Ag2(C6F5)4(phen)2]n
Authors: Luquin Asunción , Bariáin Candido , Vergara Elena , Cerrada Elena , Garrido Julian , Matias Ignacio R. , Laguna Mariano
Published: November 2005

Complexes [Au2Ag2(C6F5)4L2]n, where L = 1,10‐phenanthroline (phen), 2,2′‐bipyridine (bipy) or tetrahydrothiophene (tht), have been synthesized by reaction of NBu4[Au(C6F5)2] with Ag(SO3CF3), and the addition of phen or bipy thereafter, or with [Ag(SO3CF3)(tht)]. The organometallic vapochromic material [Au2Ag2(C6F5)4(phen)2]nis isolated as a powder that is able to detect volatile organic compounds such as acetone even in an aqueous solution. The colour of this vapochromic material changes from bright yellow to white in the presence of different donor solvents such as acetone, methanol or ethanol. For the practical construction of an optical fibre sensor, a sol‐gel doped with the vapochromic complex was deposited onto one end of a monomode fibre connected to a coupler. The behaviour of the material was studied at different wavelengths and concentrations of acetone vapours and acetone–water solutions. Changes were detected up to 4 dB in the reflected optical power. Copyright © 2005 John Wiley & Sons, Ltd.
Propylene polymerization using combined syndio‐ and isospecific metallocene catalysts supported on silica/MAO
Authors: Marques Maria De Fátima Vieira , Conte Anunciata
Published: November 2005

Syndiotactic and isotactic polypropylene were produced using the metallocene compounds Ph2C(Flu)(Cp)ZrCl2 and SiMe2(2‐Me,4‐Ph‐Ind)2ZrCl2 in homogeneous system and supported on silica/MAO. These catalysts were evaluated either isolated or as a binary system. In the latter case, the iso‐ and syndiospecific metallocene complexes were immobilized together during the preparation of the supported catalyst. In a further experimental set, the syndio‐ and isospecific isolated heterogeneous catalysts were mixed at the moment of propylene polymerization. The polypropylenes obtained were evaluated using differential scanning calorimetry. The catalytic activities were also investigated. At all the studied polymerization temperatures, the results showed that the binary catalyst produced polypropylenes with lower melting temperatures in comparison with those obtained when the mixture of isolated supported syndio‐ and isospecific catalysts was employed. Moreover, the activation energies for the polymerization of all catalysts systems were calculated, resulting in a lower value for the binary system when compared to that employing the catalyst mixture and to both the isolated supported metallocene catalysts. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 628–637, 2006
Charge storage behavior of isotropic and biaxially‐oriented polypropylene films containing α‐ and β‐nucleating agents
Authors: Behrendt Nico , Mohmeyer Nils , Hillenbrand Joachim , Klaiber Martin , Zhang Xiaoqing , Sessler Gerhard M. , Schmidt Hans‐Werner , Altstädt Volker
Published: November 2005

A study on the influence of the crystal modification (α and β) of isotactic polypropylene (i‐PP) films on the resulting electret properties is presented. Two commercial nucleating agents, sodium 2,2′‐methylene‐bis(4,6‐di‐tert‐butylphenyl)‐phosphate (NA11) and N,N′‐dicyclo‐hexyl‐2,6‐naphthalene‐dicarbox‐amide (NU100), were employed in this investigation. Isothermal charge decay was measured at 90°C. In hot pressed isotropic polypropylene films, no significant differences in the charge storage properties were observed for α‐ and β‐nucleated specimens. In addition, the article presents the influence of the nucleating agents at different concentrations on the PP‐film morphology of biaxially stretched films with respect to electret features. It was possible to prepare elongated cavities with the virtually insoluble NA11 additive during stretching, even at concentrations below 0.3 wt %. These films displayed slightly improved electret properties in comparison to stretched neat PP films due to generated cavities acting as barriers for the drift of charges. Various draw ratios were also studied for i‐PP films with 0.15 wt % NA11. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 650–658, 2006
Preparation of spherical nanocomposites consisting of silica core and polyacrylate shell by emulsion polymerization
Authors: Mizutani Tsutomu , Arai Koji , Miyamoto Masatoshi , Kimura Yoshiharu
Published: November 2005

Nanocomposite particles consisting of silica (inorganic core) and polyacrylate (organic shell) were prepared in a form of emulsion by a new and simple method—the emulsion polymerization of acrylic monomers in the presence of silica sol. The key technique of the present emulsion polymerization, which made the formation of the nanocomposites successful, is the usage of nonionic surfactant above its cloud point. The morphology of the composite was investigated by DLS, AFM, and TEM, which clearly showed formation of the core‐shell‐type particles. A transparent film was prepared by casting the emulsion, which showed high resistibility against organic solvents. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 659–669, 2006
Melting, nonisothermal crystallization behavior and morphology of polypropylene/random ethylene—propylene copolymer blends
Authors: Wang Dong , Gao Jungang
Published: November 2005

The melting, nonisothermal crystallization behavior and morphology of blends of polypropylene (PP) with random ethylene–propylene copolymer (PP‐R) were studied by differential scanning calorimetry, polarized optical microscopy, scanning electron microscopy, and X‐ray diffraction. The results showed that PP and PP‐R were very miscible and cocrystallizable. Modified Avrami analysis was used to analyze the nonisothermal crystallization kinetics of the blends. The values of the Avrami exponent indicated that the crystallization nucleation of the blends was heterogeneous, the growth of the spherulites was tridimensional, and the crystallization mechanism of PP was not affected by PP‐R. The crystallization activation energy was estimated using the Kissinger method. An interesting result was obtained with the modified Avrami analysis and the Kissinger method, whose conclusions were in good agreement. The addition of a minor PP‐R phase favored an increase in the overall crystallization rate of PP. Maximum enhancing effect wass found to occur with a PP‐R content of 20 wt %. The relationship between the composition and the morphology of the blends is discussed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 670–678, 2006
Surface modification of polyimide films by argon plasma for copper metallization on microelectronic flex substrates
Authors: Lin Yung‐Sen , Liu Huang‐Ming , Chen Hsuan‐Ta
Published: November 2005

Surface modification of polyimide films such as Kapton E(N) and Upilex S by argon plasma was investigated because of the enhanced adhesive strength with sputtered copper. Peel tests demonstrated this improvement, with a peel strength of 0.7 and 1.2 g/mm for unmodified Kapton E(N) and Upilex S, respectively, and 110.3 and 98 g/mm for argon plasma–modified Kapton E(N) and Upilex S, respectively, in certain plasma conditions. This study showed that the enhanced adhesive strength of polyimide films with sputtered copper by argon plasma was strongly affected by the surface characteristics such as surface morphology and surface energy of polyimide films. Atomic force microscopy and the sessile drop method indicated that the surface roughness and surface energy of the polyimide films were greatly increased by argon plasma, resulting in highly increased peel strength of the polyimide films with sputtered copper. It was observed in electron spectroscopy for chemical analysis (ESCA) that the increased surface energy of the polyimide films from argon plasma was a result of more of the surface being composed of O and N and of the increased number of CO, CO, and CN chemical bonds. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 744–755, 2006
Structural and mechanical characterization of poly(ether ether ketone) (PEEK) and sulfonated PEEK films: Effects of thermal history, sulfonation, and preparation conditions
Authors: Reyna‐Valencia A. , Kaliaguine S. , Bousmina M.
Published: November 2005

In this work, virgin and sulfonated poly(ether ether ketone) films (PEEK and SPEEK, respectively) have been studied by dynamic mechanical analysis, modulated differential scanning calorimetry, wide‐angle X‐ray diffraction, birefringence, and optical microscopy. The properties of the unmodified polymer have been addressed to assess the original morphological characteristics and the changes induced by sulfonation. In general, the introduction of ionic groups in the polymer backbone alters dramatically the intrinsic properties of the parent material. The particular thermomechanical response exhibited by PEEK and SPEEK samples, characterized by a hysteresis loop, can be explained by the reversible and irreversible relaxation–orientation of the microstructure, even in the sub‐Tg region. The results showed that the preparation conditions largely determine the nonequilibrium morphological features of both compression‐molded PEEK films and solvent‐cast SPEEK membranes. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 756–774, 2006
Characterization of PVC cable insulation materials and products obtained after removal of additives
Authors: Beneš M. , Plaček V. , Matuschek G. , Kettrup A. , Györyová K. , Balek V.
Published: November 2005

Organic solvents cyclohexane, dichloromethane, hexane, and tetrahydrofuran were tested to separate the dioctylphthalate (DOP) as plasticizer from the poly(vinyl chloride) (PVC)‐based materials. It was found that the efficiency of ultrasound‐enhanced hexane extraction of the DOP from PVC is 70% and the efficiency of the separation of the DOP and other compounds from the PVC by dissolution in THF followed by subsequent precipitation was 98–99%. Differential scanning calorimetry (DSC) and thermogravimetry (TG) were used to characterize the thermal behavior of PVC materials before and after extraction of plasticizers. It was found that during heating in the range 20–800°C the total mass loss measured for the nontreated, extracted, and precipitated PVC samples was 71.6, 66.6, and 97%, respectively. In the temperature range 200–340°C, the release of DOP, HCl, and CO2 was observed by simultaneous thermogravimetry (TG)/FTIR. The effect of plasticizers on thermal behavior of PVC‐based insulation material was characterized by DSC in the range −40–140°C. It was found that, concerning the PVC cable insulation material before treatment, the value of the glass transition temperature (Tg) was 1.4°C, whereas for the PVC sample extracted by hexane, the value of Tg was 39.5°C and for the PVC dissolved in THF and subsequently precipitated, the value of Tg was 80.4°C. Moreover, the PVC samples after extraction of plasticizers, fillers, and other agents were tested to characterize their thermal degradation. The TG and FTIR results of chemically nontreated, extracted, and precipitated samples were compared. The release of DOP, HCl, CO2, and benzene was studied during thermal degradation of the samples by FTIR. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 788–795, 2006
Resins with the ability to bind copper and uranyl ions
Authors: Rivas Bernabé L. , Pereira Eduardo , Jara Miguel , Esparza Carolina
Published: November 2005

Crosslinked poly(1‐vinyl imidazole‐co‐acrylic acid) and crosslinked poly(1‐vinylmidazole‐co‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) were synthesized by radical polymerization and characterized by elemental analysis and FTIR spectroscopy. The polymerization yields were 79 and 99%, respectively. The metal ion binding properties for copper(II) and uranium(VI) were studied under noncompetitive and competitive conditions by Batch equilibrium procedure. The resin crosslinked poly(1‐vinyl imidazole‐co‐acrylic acid) showed a higher dependence on pH than crosslinked poly(1‐vinylmidazole‐co‐2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid). The retention of uranyl ions for the latter resin was close to 100% at pH 5.0. The higher maximum retention capacity was close to 0.8 mmol/g dry resin at pH 5.0. Regeneration of the resin was possible by treatment with basic eluent. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 706–711, 2006
Further investigation of polyaminoamide‐epichlorohydrin/stearic anhydride compatibilizer system for wood‐polyethylene composites
Authors: Geng Y. , Li K. , Simonsen J.
Published: November 2005

The combination of a polyaminoamide‐epichlorohydrin (PAE) resin (a paper wet strength agent) and stearic anhydride was recently reported as an effective compatibilizer system for wood‐polyethylene composites. Further investigation of this new compatibilizer system revealed that the pH value of a PAE solution, dosages of PAE and stearic anhydride, and the weight ratio of PAE to stearic anhydride had significant impacts on the compatibilization effects of the compatibilizer system. Adjusting the pH value of the PAE solution from 5.0 to 10.4 increased the strength of the resulting wood‐polyethylene composites. The highest strength of the resulting wood‐polyethylene composites was obtained at 3 wt % PAE and 3 wt % stearic anhydride. At 4 wt % or 6 wt % of a compatibilizer, this PAE‐stearic anhydride system was superior to maleic anhydride‐grafted polyethylene (MAPE), one of the most effective compatibilizers, in terms of enhancing the strength of the resulting wood‐polyethylene composites. Fourier transform infrared spectroscopy (FTIR) analysis revealed that PAE and stearic anhydride formed covalent bonding with wood flour. The compatibilization mechanisms of this PAE‐stearic anhydride compatibilizer system were investigated in detail. Water‐resistance tests indicated that the PAE‐stearic anhydride compatibilizer system increased the water‐resistance of the resulting composites. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 712–718, 2006
Synthesis and characterization of poly(N‐methyl aniline) doped with sulphonic acids: Their application as humidity sensors
Authors: Kulkarni Milind V. , Viswanath Annamraju Kasi , Khanna P. K.
Published: November 2005

Single step chemical polymerization of N‐methyl aniline was carried out by using ammonium persulphate as an oxidizing agent. The conducting emeraldine salt phase of the polymers using camphor sulfonic acid and p‐toluene sulfonic acid as dopants was made by a direct process. The polymers were characterized by UV‐vis and FTIR spectroscopy, scanning electron microscopy, TGA, and conductivity measurements. The synthesized polymers were found to have very good physicochemical properties and good electrical conductivity. Conductivity measurements have shown “thermal activated behavior.” The change in resistance with respect to % relative humidity (RH) was observed, when pressed pellets of the polymer were exposed to the broad range of humidity (ranging between 20 and 100% RH). © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 812–820, 2006
Carbon‐13 NMR, GPC, and DSC study on a propylene‐1‐butene copolymer fractionated by temperature rising elution fractionation
Authors: Zhang Yudong
Published: November 2005

A random copolymer of propylene with small amounts of 1‐butene comonomer, synthesized with a Ziegler–Natta catalyst, was fractionated by temperature rising elution fractionation (TREF) to systemically investigate the fraction samples' molecular microstructure, as well as their relationship to the melting and crystallization behavior. First, TREF was employed to fractionate the sample, and then crystallization analysis fractionation (Crystaf) was used to check the effect of the TREF experiment. In the characterization of the molecular microstructure, carbon‐13 NMR spectroscopy (13C NMR) and gel permeation chromatography (GPC) experiments gave the following results: the fraction samples have relatively uniform molecular microstructure; with an increase in elution temperature, the 1‐butene content in the fraction samples decreases, but the molecular weight (Mn) and number average sequence length of propylene (n̄P) increase. In the study on melting and crystallization behavior, differential scanning calorimetry (DSC) experimental results show that the melting temperature increasingly decreases with an increase in 1‐butene content; however, dependence of the melting temperature on molecular weight becomes weaker and weaker with an increase in the number average molecular weight in the range of number average molecular weight below 1.82 × 105 g/mol. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 845–851, 2006
Micro‐structure and characteristics of highly oriented polyoxymethylene obtained by press and biaxial drawing
Authors: Takasa Kenji , Miyashita Norikazu , Takeda Kunihiko
Published: November 2005

The physical structure of oriented polyoxymethylene (POM) drawn in two steps by press drawing and subsequent simultaneous biaxial drawing was studied. The degree of crystallinity, the orientation, and the tensile modulus depending on draw ratio were analyzed. By the press drawing method, the draw ratio reached 6.0, the tensile modulus was 4.5 GPa, and the degree of crystallinity decreased from 70% to 65%. By the two‐step drawing of press drawing followed by subsequent simultaneous biaxial drawing, the tensile modulus reached 11 GPa when the draw ratio was 14 times, and the degree of crystallinity increased from 71% to 76–80%, but it did not depend on the draw ratio, and showed effectively a constant value (average 77%). The physical structural properties, such as the degree of crystallinity, the orientation of the crystal, and the lamella structure, were analyzed by SEM, X‐ray diffraction, and other methods. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 835–844, 2006
Preparation and curing kinetics of bisphenol A type novolac epoxy resins
Authors: Liu Yanfang , Zhang Chen , Du Zhongjie , Li Hangquan
Published: November 2005

A bisphenol A type novolac resin (Bis‐ANR) was synthesized from bisphenol A and formaldehyde; the resulting novolac was epoxidized to generate a bisphenol A type novolac epoxy resin (Bis‐ANER). The chemical structures of Bis‐ANR and Bis‐ANER were confirmed by 1H‐NMR spectroscopy and IR spectroscopy; the molecular weights and molecular weight distributions were determined by gel permeation chromatography. In addition, the curing process of Bis‐ANER with 4,4′‐diaminodiphenyl sulfone was studied in both dynamic and isothermal modes with differential scanning calorimetry. The dynamic curing kinetic analysis was evaluated with both the Kissinger and Flynn–Wall–Ozawa methods, and the curing activation energy values were obtained. The isothermal curing reaction exhibited autocatalytic behavior, and the curing kinetics were described with the Kamal kinetics model, which accounted for both the autocatalytic and diffusion‐control effects. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 858–868, 2006
Synthesis and Biological Activity of Novel Acyclic Versions of NeplanocinA
Authors: Wu Ying , Hong Joon Hee
Published: November 2005

Novel acyclic Neplanocin A analogues were designed and synthesized. The coupling of the alkyl bromide 6 with nucleosidic bases (T, U, 5‐FU, 5‐IU, C, A) and desilylation afforded a series of novel acyclic nucleosides. The synthesized compounds 13–18 were evaluated for their antiviral and antitumor activity.
The Topical Protective Effect of Soybean‐Germ Oil against UVB‐Induced Cutaneous Erythema: an in vivo Evaluation
Authors: Bonina Francesco , Puglia Carmelo , Avogadro Milvio , Baranelli Enzo , Cravotto Giancarlo
Published: November 2005

The preparation and detailed composition of an oil newly extracted from pure soy germ (not less than 96 % hypocotyle) are presented. Experiments in vivo showed that soybean‐germ oil (SGO) possesses a remarkable protective activity against UVB‐induced skin inflammation, exceeding that of tocopherol acetate by a factor of 2. These results suggest that SGO might have interesting therapeutic and cosmetic applications in the management of skin diseases initiated, sustained, or exacerbated by an over production of free radicals.
Synthesis and Antiviral Evaluation of Novel Exomethylene Acyclic Nucleosides and Phosphonic Acid Nucleosides
Authors: Kim Aihong , Hong Joon Hee
Published: November 2005

This paper describes a very simple synthesis route of novel acyclic nucleosides and phosphonic acid nucleosides. The condensation of the mesylates 6 and 17 with the natural nucleosidic bases (A, C, U, T) under nucleophilic substitution (K2CO3, 18‐Crown‐6, DMF) and deprotection afforded the target nucleosides (11, 12, 13, 14) and phosphonic acid nucleosides (22, 23, 24, 25). In addition, these compounds were evaluated for their antiviral properties against various viruses. Uracil derivative 24 shows significant anti‐HCMV activity (EC50 = 10.24 μM).
Citation rates and perceptions of scientific contribution
Authors: Aksnes Dag W.
Published: November 2005

In this study scientists were asked about their own publication history and their citation counts. The study shows that the citation counts of the publications correspond reasonably well with the authors' own assessments of scientific contribution. Generally, citations proved to have the highest accuracy in identifying either major or minor contributions. Nevertheless, according to these judgments, citations are not a reliable indicator of scientific contribution at the level of the individual article. In the construction of relative citation indicators, the average citation rate of the subfield appears to be slightly more appropriate as a reference standard than the journal citation rate. The study confirms that review articles are cited more frequently than other publication types. Compared to the significance authors attach to these articles they appear to be considerably “overcited.” However, there were only marginal differences in the citation rates between empirical, methods, and theoretical contributions.
Link‐based similarity measures for the classification of Web documents
Authors: Calado Pável , Cristo Marco , Gonçalves Marcos André , de Moura Edleno S. , Ribeiro‐Neto Berthier , Ziviani Nivio
Published: November 2005

Traditional text‐based document classifiers tend to perform poorly on the Web. Text in Web documents is usually noisy and often does not contain enough information to determine their topic. However, the Web provides a different source that can be useful to document classification: its hyperlink structure. In this work, the authors evaluate how the link structure of the Web can be used to determine a measure of similarity appropriate for document classification. They experiment with five different similarity measures and determine their adequacy for predicting the topic of a Web page. Tests performed on a Web directory show that link information alone allows classifying documents with an average precision of 86%. Further, when combined with a traditional text‐based classifier, precision increases to values of up to 90%, representing gains that range from 63 to 132% over the use of text‐based classification alone. Because the measures proposed in this article are straightforward to compute, they provide a practical and effective solution for Web classification and related information retrieval tasks. Further, the authors provide an important set of guidelines on how link structure can be used effectively to classify Web documents.
Schienenlängskräfte auf Brücken bei nichtlinearer Überlagerung der Lastfälle Temperatur, Tragwerksbiegung, Bremsen
Authors: Ruge Peter , Birk Carolin , Muncke Martin , Schmälzlin Gerd
Published: November 2005

Der DIN‐Fachbericht 101, der auch für Eisenbahnbrücken gilt, sieht eine getrennte jeweils nichtlineare Betrachtung der genannten drei Lastfälle und eine anschließende Summation der Teil ergebnisse vor. Bei diesem Vorgehen wird der Einfluß der Vorgeschichte auf die nachfolgende Lastabtragung vollkommen vernachlässigt.

Dieser Aufsatz zeigt erstmals den Einfluß einer korrekten Erfassung der Lastfolge Temperatur – Tragwerksbiegung – Bremsen/Anfahren bei Berücksichtigung der Vorgeschichte auf die Längsbeanspruchung lückenlos verschweißter Gleise sowohl für das Schottergleis als auch für die Feste Fahrbahn.
Oxygen gradients correlate with cell density and cell viability in engineered cardiac tissue
Authors: Radisic Milica , Malda Jos , Epping Eric , Geng Wenliang , Langer Robert , Vunjak‐Novakovic Gordana
Published: November 2005

For clinical utility, cardiac grafts should be thick and compact, and contain physiologic density of metabolically active, differentiated cells. This involves the need to control the levels of nutrients, and most critically oxygen, throughout the construct volume. Most culture systems involve diffusional transport within the constructs, a situation associated with gradients of oxygen concentration, cell density, cell viability, and function. The goal of our study was to measure diffusional gradients of oxygen in statically cultured cardiac constructs, and to correlate oxygen gradients to the spatial distributions of cell number and cell viability. Using microelectrodes, we measured oxygen distribution in a disc‐shaped constructs (3.6 mm diameter, 1.8 mm thickness) based on neonatal rat cardiomyocytes cultured on collagen scaffolds for 16 days in static dishes. To rationalize experimental data, a mathematical model of oxygen distribution was derived as a function of cell density, viability, and spatial position within the construct. Oxygen concentration and cell viability decreased linearly and the live cell density decreased exponentially with the distance from the construct surface. Physiological density of live cells was present only within the first 128 µm of the construct thickness. Medium flow significantly increased oxygen concentration within the construct, correlating with the improved tissue properties observed for constructs cultured in convectively mixed bioreactors. © 2005 Wiley Periodicals, Inc.
Modeling product formation in anaerobic mixed culture fermentations
Authors: Rodríguez Jorge , Kleerebezem Robbert , Lema Juan M. , van Loosdrecht Mark C.M.
Published: November 2005

The anaerobic conversion of organic matter to fermentation products is an important biotechnological process. The prediction of the fermentation products is until now a complicated issue for mixed cultures. A modeling approach is presented here as an effort to develop a methodology for modeling fermentative mixed culture systems. To illustrate this methodology, a steady‐state metabolic model was developed for prediction of product formation in mixed culture fermentations as a function of the environmental conditions. The model predicts product formation from glucose as a function of the hydrogen partial pressure (PH2), reactor pH, and substrate concentration. The model treats the mixed culture as a single virtual microorganism catalyzing the most common fermentative pathways, producing ethanol, acetate, propionate, butyrate, lactate, hydrogen, carbon dioxide, and biomass. The product spectrum is obtained by maximizing the biomass growth yield which is limited by catabolic energy production. The optimization is constrained by mass balances and thermodynamics of the bioreactions involved. Energetic implications of concentration gradients across the cytoplasmic membrane are considered and transport processes are associated with metabolic energy exchange to model the pH effect. Preliminary results confirmed qualitatively the anticipated behavior of the system at variable pH and PH2 values. A shift from acetate to butyrate as main product when either PH2 increases and/or pH decreases is predicted as well as ethanol formation at lower pH values. Future work aims at extension of the model and structural validation with experimental data. © 2005 Wiley Periodicals, Inc.
Investigation of protein retention and selectivity in HIC systems using quantitative structure retention relationship models
Authors: Ladiwala Asif , Xia Fang , Luo Qiong , Breneman Curt M. , Cramer Steven M.
Published: November 2005

In the present work, the effect of stationary phase resin chemistry and protein physicochemical properties on protein binding affinity in hydrophobic interaction chromatography (HIC) was investigated using linear gradient chromatography and quantitative structure‐retention relationship (QSRR) modeling. Linear gradient experiments were carried out for a set of model proteins on four different HIC resins having different backbone and ligand chemistry. The retention data exhibited significant differences in protein binding affinity, not only across the phenyl and butyl ligand chemistries, but also for the different backbone chemistries found in the Sepharose (cross‐linked agarose) and the Toyopearl 650 M (polymethacrylate) series of resins. QSRR models based on a Support Vector Machine (SVM) approach were developed for the linear retention data using molecular descriptors based on protein crystal structure and primary sequence information as well as a set of new hydrophobicity descriptors based on the solvent accessible protein surface area. The results indicate that the QSRR models were successfully able to capture and selectivity predict the changes observed in these systems. Furthermore, the new descriptors resulted in physically interpretable models of protein retention and provided insights into the factors influencing protein affinity in these different HIC systems. The approach put forth in this study provides a framework for developing predictive tools and for gaining insight into protein selectivity in hydrophobic interaction chromatography. © 2005 Wiley Periodicals, Inc.
Laparoscopic liver resection
Authors: Vibert E , Perniceni T , Levard H , Denet C , Shahri N K , Gayet B
Published: November 2005

Background

This paper describes a 10-year experience of laparoscopic liver surgery, including several major hepatectomies for malignant tumours.

Methods

Of 243 hepatectomies carried out between January 1995 and December 2004, 113 (46·5 per cent) were performed by laparoscopy and 89 were included in this retrospective study.

Results

Twenty-four laparoscopic hepatectomies (27 per cent) were for benign disease and 65 (73 per cent) for malignant tumours, including hepatocellular carcinoma (HCC) in 16 patients and colorectal metastasis (CRM) in 41. Minor hepatectomy was performed in 51 patients and major hepatectomy (three or more Couinaud segments) in 38. Conversion to laparotomy was necessary in 12 patients and perioperative blood transfusion in eight. One patient with cirrhosis who underwent right hepatectomy for HCC with conversion to open surgery died 8 days after surgery. Major morbidity occurred in eight patients (16 per cent) having minor hepatectomy and in 11 (29 per cent) of those having a major resection. The 3-year overall and disease-free survival rates for patients with CRM (mean follow-up 30 months) were 87 (11 patients at risk) and 51 (6 patients at risk) per cent respectively. Corresponding values for patients with HCC (mean follow-up 40 months) were 85 (10 patients at risk) and 68 (5 patients at risk) per cent.

Conclusion

In experienced hands, the results of laparoscopic liver surgery are similar to those for laparotomy.
Meta-analysis of colonic reservoirs versus straight coloanal anastomosis after anterior resection
Authors: Heriot A G , Tekkis P P , Constantinides V , Paraskevas P , Nicholls R J , Darzi A , Fazio V W
Published: November 2005

Background and methods

The comparative benefits and drawbacks of straight coloanal anastomosis (CAA), colonic J-pouch and coloplasty anastomosis after anterior resection are uncertain. Studies published between 1986 and 2005 of colonic J-pouch versus transverse coloplasty or straight CAA were analysed. Endpoints included postoperative complications, and functional and physiological outcomes measured within 6 months, 1 year and 2 years or more after the procedure. A random-effect model was used to aggregate the study endpoints and assess heterogeneity.

Results

Thirty-five studies containing 2240 patients (1066 straight CAA, 1050 J-pouch and 124 coloplasty) were included. There was no significant difference in postoperative complications between the three groups. There was a significant reduction in the frequency of defaecation per day by 1·88, 1·35 and 0·74 motions at the three time intervals in the J-pouch group compared with the straight CAA group. Faecal urgency was less prevalent in patients with a J-pouch than those with a straight CAA (odds ratio 0·27 at 6 months or less and 0·21 at 1 year). There was no difference in functional outcome between J-pouch and coloplasty anastomosis.

Conclusions

The colonic J-pouch provided functional benefits over straight anastomosis with no increase in postoperative complications. Coloplasty appeared to have similar benefits but further studies are required for validation.
Lap‐belt injury with complete avulsion of the spinal cord and cauda equina
Authors: Tubbs R. Shane , Golden Blake , Doyle Scott , Grabb Paul A. , Oakes W. Jerry
Published: November 2005

The authors report a child who was involved in an automobile accident. The patient was restrained by a rear seat lap belt. Radiological examination revealed an L4 Chance‐type fracture and ligamentous disruption at the L4–L5 interval. During superficial dissection of the paraspinal muscles for a spinal fusion procedure, the cauda equina and the lower spinal cord (several centimeters) were visible, completely transected and herniated into the extraspinal space through a disrupted thoracolumbar fascia. The clinician should be aware of the potentially devastating results following a lap‐belt injury in which a Chance fracture is produced. Clin. Anat. 19:665–668, 2006. © 2005 Wiley‐Liss, Inc.
Mechanical contribution of the fibula to torsion stiffness in the lower extremity
Authors: Thambyah A. , Pereira B.P.
Published: November 2005

The role of the fibula in rotational stability of the lower extremity, taking into account the intact knee joint and tibia, to the best of our knowledge, has not been investigated. A cadaver study was designed to determine the torque transfer down the lower extremity, with and without the fibula. Six fresh, frozen human cadaver legs were used. The knee joint was left intact and the foot disarticulated. An external rotation up to 5°, coupled with axial compression, was applied to the femur passing through the knee joint in extension and down the lower extremity to the fixed distal end, where torque (N m) was measured via a load cell. Each specimen was further tested with the fibula, cut 4 cm from the distal end, and finally with the entire fibula disarticulated at the proximal end and removed. To achieve 5° rotation, torques reached 1.82 N m (SD, 0.66 N m). When the fibula was cut, the torque reduced a small yet significant amount of 5%. With the entire fibula removed, the torque reduction was significant and more pronounced at 11%. The fibula provided a small yet significant role in torsion stability. From this study, where the biomechanical characteristics of the fibula is explicated, it is hoped that this information will have use in further understanding the biomechanical role of the fibula, especially, in relation to the altered mechanics associated with lower limb pathology involving a deficient fibula. Clin. Anat. 19:615–620, 2006. © 2005 Wiley‐Liss, Inc.