bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Telechelic Oligomers via Atom Transfer Radical Polymerization, 3
Authors: Otazaghine Belkacem , Boutevin Bernard
Published: September 2004

Summary: ATRP of butyl α‐fluoroacrylate (FABu) was carried out at 90 °C using methyl 2‐bromoisobutyrate (2‐MBiB) as initiator and the homogeneous catalyst CuBr/1,1,4,7,10,10‐hexamethyltriethylenetetramine (HMTETA). Telechelic oligomers were obtained by coupling the bromo terminated polymers in the presence of Cu(0) and 2,2′‐bipyridyl ligand. The 1H and 19F NMR, SEC and MALDI TOF analyses show that the poly(FABu) chains recombination was the main reaction (80% yield). About 20% of disproportionation reaction also occurs in the process, whereas transfer reactions can be neglected.

Compounds produced by recombination, disproportionation and transfer during the coupling reaction of poly(FABu) oligomers.

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Compounds produced by recombination, disproportionation and transfer during the coupling reaction of poly(FABu) oligomers.
Synthesis of Poly(3‐hexylthiophene) with a Narrower Polydispersity
Authors: Miyakoshi Ryo , Yokoyama Akihiro , Yokozawa Tsutomu
Published: September 2004

Summary: The polymerization of 2‐bromo‐3‐hexyl‐5‐iodothiophene (1) with isopropylmagnesium chloride and Ni(dppp)Cl2 was quenched with 5 M hydrochloric acid instead of water to yield head‐to‐tail poly(3‐hexylthiophene) (HT‐P3HT) with a very low polydispersity. The $\overline M _{\rm n}$ of the polymer was controlled by the feed ratio of 1 to Ni(dppp)Cl2. Quenching with 5 M hydrochloric acid seemed to promote protonolysis of HT‐P3HT‐Ni complexes before the coupling reaction between HT‐P3HT.

GPC profiles of HT‐P3HT obtained after quenching with water and 5 M hydrochloric acid, respectively.

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GPC profiles of HT‐P3HT obtained after quenching with water and 5 M hydrochloric acid, respectively.
Cover Picture: Macromol. Rapid Commun. 18/2004
Authors: Naga Naofumi , Toyota Akinori
Published: September 2004

Cover: The cover picture summarizes the copolymerization mechanism of ethylene and 1,7‐octadiene (OD) with a constrained‐geometry catalyst 1. The inserted OD unit formed unexpected 1,5‐cyclononane units as well as 1,3‐cycloheptane units in the main chain of polyethylene. This characteristic cyclononane cyclic unit would be derived from a unique OD cyclization insertion mode: cyclization insertion of the OD unit in the penultimate position after a single ethylene insertion step.

Further details can be found in the Communication by N. Naga* and A. Toyota on page 1623.
Tremor as the first neurological manifestation of Sneddon's syndrome
Authors: Martins Da Silva A. , Rocha N. , Pinto M. , Alves V. , Farinha F. , Correia A.P. , Coelho T. , Magalhães M.
Published: September 2004

We report on a 54‐year‐old woman with Sneddon's syndrome manifested by livedo reticularis, fetal losses, hypertension, and high antinuclear antibody titres. At the age of 42 years she developed tremor of the trunk, limbs, and head only in the standing position that interfered with walking, followed some years later by cognitive decline and a parkinsonian syndrome. T2‐weighted brain magnetic resonance imaging showed high signal in cortical areas, basal ganglia, midbrain, and cerebellum. © 2004 Movement Disorder Society
Atypical parkinsonism combining α‐synuclein inclusions and polyglucosan body disease
Authors: Krim Elsa , Vital Anne , Macia Frederic , Yekhlef Farid , Tison François
Published: September 2004

Adult polyglucosan body disease (APGBD) is a rare disorder affecting the central and peripheral nervous systems and in which parkinsonism is unusual. A 71‐year‐old man presented levodopa‐unresponsive parkinsonism with urinary incontinence and recurrent syncopes of 6 years standing masquerading as atypical parkinsonism of the multiple system atrophy (MSA‐P) type. Brain histopathology demonstrated massive accumulation of polyglucosan bodies particularly in the putamen. In addition, there were dense α‐synuclein–positive cytoplasmic oligodendroglial inclusions in the pons and in the middle cerebellar peduncle. These inclusions may be either due to the chance association of MSA‐P with APGBD, or pathologically related to APGBD. © 2004 Movement Disorder Society
Multiple system atrophy with macrosquare‐wave jerks
Authors: Klotz Luisa , Klockgether Thomas
Published: September 2004

Macrosquare‐wave jerks consist of high‐amplitude saccadic intrusions occurring mainly during fixation that are observed in several disease entities, e.g., multiple sclerosis or parkinsonian syndromes, but very rarely in patients with multiple system atrophy. We present here a patient with multiple system atrophy exhibiting the oculomotor feature of macrosquare‐wave jerks. © 2004 Movement Disorder Society
Grip force behavior in Gilles de la Tourette syndrome
Authors: Nowak Dennis A. , Rothwell John , Topka Helge , Robertson Mary M. , Orth Michael
Published: September 2004

We analyzed predictive and reactive grip force behavior in 15 patients with Gilles de la Tourette syndrome (GTS) and 15 sex‐ and age‐matched healthy control subjects. Nine patients were without medication; six patients were on medication. In a first experiment, participants lifted and held instrumented objects of different weight. In a second experiment, participants performed vertical point‐to‐point and continuous arm movements at different frequencies with a hand‐held object. In a third experiment, preparatory and reactive grip force responses to sudden load perturbations were analyzed when a weight was dropped into a hand‐held cup either by the subject or unexpectedly by the experimenter. Compared to the healthy subjects, GTS patients had increased grip forces relative to the load force in all tasks. Despite this finding, they adjusted the grip force to changes in load force (due to either a change in the mass lifted or accelerating the mass during continuous movements) in the same way as healthy subjects. The temporal coupling between grip and load force profiles was also similar in patients and healthy controls, and they displayed normal anticipation of impact forces when they dropped a weight into a hand‐held cup. We found no significant effect of medication on the performance of GTS patients, regardless of the task performed. These results are consistent with deficient sensory–motor processing in Gilles de la Tourette syndrome. © 2004 Movement Disorder Society
Design of follow‐up experiments for improving model discrimination and parameter estimation
Authors: Ng Szu Hui , Chick Stephen E.
Published: September 2004

One goal of experimentation is to identify which design parameters most significantly influence the mean performance of a system. Another goal is to obtain good parameter estimates for a response model that quantifies how the mean performance depends on influential parameters. Most experimental design techniques focus on one goal at a time. This paper proposes a new entropy‐based design criterion for follow‐up experiments that jointly identifies the important parameters and reduces the variance of parameter estimates. We simplify computations for the normal linear model by identifying an approximation that leads to a closed form solution. The criterion is applied to an example from the experimental design literature, to a known model and to a critical care facility simulation experiment. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004
On optimization of bio‐probes
Authors: Pedersen N. L.
Published: September 2004

The present paper deals with the modelling and optimization of small bio‐probes that can be used for biological sensing; the bio‐probes can be classified as MicroElectroMechnical Systems (MEMS). The objective is to optimize the structure of the bio‐probes in order to maximize the sensing sensitivity. A biological coating results in a prestress on the sensing cantilever when certain molecules are present in the surrounding medium. The mechanical deformation due to the biological material is modelled by applying a prestress in the top layer of the bio‐probes. Topology optimization is used to improve the design. In the present work it is necessary to use an interpolation scheme different from the SIMP (power law) approach which is usually used in topology optimization. In calculating the sensitivities, needed for the optimization, complications due to the prestress occur, but also due to the coupling between the elastic field and the electric field which both must be used in an integrated model. These complications are dealt with and analytically obtained sensitivities are presented. Copyright © 2004 John Wiley & Sons, Ltd.
On the stable finite element procedures for dynamic problems of saturated porous media
Authors: Huang Maosong , Yue Zhong Qi , Tham L. G. , Zienkiewicz O. C.
Published: September 2004

The solution of problems in which coupling occurs between the displacement of the soil skeleton and the pore fluid pressure is fundamental in soil dynamics. The formulation requires that the interpolation functions for the displacement and pressure in the finite element discretization must satisfy the so‐called Babuska–Brezzi stability criteria or the patch test in the limit of nearly incompressible pore fluid and small permeability. The criteria are not fulfiled by elements with the same order of interpolation for both variables unless stabilization techniques are introduced. This paper summarizes the stabilization techniques that have been proposed in the literature to overcome volumetric locking for the incompressible or nearly incompressible soil dynamic behaviours. In particular, the staggered implicit–implicit algorithm (i.e. the fractional step method in an implicit form) and the direct α‐method proposed by the first author and Zienkiewicz et al. are briefly reviewed. Attentions will be paid to the steady‐state formulations resulted from both approaches. Based on the steady state formulations, the paper will then discuss the determination of the local stabilization parameters, with which a significant improvement for the obtained solutions of pore‐pressure can be achieved. Further discussion on the limitations of the methods is also given. Finally, several numerical examples are presented to illustrate the effectiveness of the proposed techniques. Copyright © 2004 John Wiley & Sons, Ltd.
A super‐element for crack analysis in the time domain
Authors: Song Chongmin
Published: September 2004

A super‐element for the dynamic analysis of two‐dimensional crack problems is developed based on the scaled boundary finite‐element method. The boundary of the super‐element containing a crack tip is discretized with line elements. The governing partial differential equations formulated in the scaled boundary co‐ordinates are transformed to ordinary differential equations in the frequency domain by applying the Galerkin's weighted residual technique. The displacements in the radial direction from the crack tip to a point on the boundary are solved analytically without any a priori assumption. The scaled boundary finite‐element formulation leads to symmetric static stiffness and mass matrices. The super‐element can be coupled seamlessly with standard finite elements. The transient response is evaluated directly in the time domain using a standard time‐integration scheme. The stress field, including the singularity around the crack tip, is expressed semi‐analytically. The stress intensity factors are evaluated without directly addressing singular functions, as the limit in their definitions is performed analytically. Copyright © 2004 John Wiley & Sons, Ltd.
Constrained boundary recovery for three dimensional Delaunay triangulations
Authors: Du Qiang , Wang Desheng
Published: September 2004

A new constrained boundary recovery method for three dimensional Delaunay triangulations is presented. It successfully resolves the difficulties related to the minimal addition of Steiner points and their good placement. Applications to full mesh generation are discussed and numerical examples are provided to illustrate the effectiveness of guaranteed recovery procedure. Copyright © 2004 John Wiley & Sons, Ltd.
On using linear elements in incompressible plane strain problems: a simple edge based approach for triangles
Authors: Boroomand B. , Khalilian B.
Published: September 2004

In this paper a simple iterative method is presented for finite element solution of incompressible plane strain problems using linear elements. Instead of using a mixed formulation approach, we use an equivalent displacement/velocity approach in an iterative manner. Control volumes are taken for regions which are to exhibit incompressible behaviour. For triangular elements the control volume is chosen as the area built on the parts of each pair of elements at the sides of an edge. In this case, elements are let to exchange volume. It is shown that the proposed edge based approach removes the deficiency of the linear triangular elements i.e. locking effect.

Similar edge based approach is applied to the linear quadrilateral elements. However, if the control volume is chosen as the element volume the formulation gives similar results as the discontinuous mixed formulation using one pressure point without exhibiting instability behaviour. The formulation is based on decomposition of the displacement/velocity field into deviatoric and volumetric parts. The volumetric part is iteratively eliminated without confronting locking or instability phenomenon. The iterative procedure is very cheap and simple to be implemented in any FEM code. Several examples are given to demonstrate the performance of the procedure. Copyright © 2004 John Wiley & Sons, Ltd.
Regulatory impact assessment and regulatory governance in developing countries
Authors: Kirkpatrick Colin , Parker David
Published: September 2004

Regulatory impact assessment (RIA) offers the means to improve regulatory decision‐making and practice. RIA involves a systematic appraisal of the costs and benefits associated with a proposed new regulation and evaluation of the performance of existing regulations. So far, the adoption of RIA has been confined mainly to OECD countries. The purpose of this article is to assess the contribution that RIA can make to ‘better regulation’ in developing countries. Results from a survey of a small number of middle‐income countries suggest that a number of developing countries apply some form of regulatory assessment, but that the methods adopted are partial in their application and are certainly not systematically applied across government. The article discusses the capacity building requirements for the adoption of RIA in developing countries, in terms of regulatory assessment skills, including data collection methods and public consultation practices. The article also proposes a framework for RIA that can be applied in low and middle‐income countries to improve regulatory decision‐making and outcomes. Copyright © 2004 John Wiley & Sons, Ltd.
Privatisation and liberalisation in the utility sector: the case of telecommunications in the Czech and Slovak Republics
Authors: Nemec Juraj , Sagat Vladimir , Vitek Leos
Published: September 2004

This article addresses the issue of telecommunications reform in the context of economic, political and technological changes. It reviews recent approaches to utilities and telecommunications management from the perspective of socio‐economic theories and with reference to European Union (EU) telecommunications policies. It then addresses telecommunications reform in the Czech and Slovak Republics as they prepare to join the EU. The emphasis is on the efficiency, pricing, quality and scope of services, as well as the social consequences of liberalisation. The indications are that, while liberalisation is favoured, certain basic government guarantees are still required in the ‘public interest’. Copyright © 2004 John Wiley & Sons, Ltd.
CDX1 expression is reduced in colorectal carcinoma and is associated with promoter hypermethylation
Authors: Pilozzi Emanuela , Onelli Mariadele Rapazzotti , Ziparo Vincenzo , Mercantini Paolo , Ruco Luigi
Published: September 2004

The CDX1 homeobox gene encodes a transcription factor specifically expressed in normal intestinal and colonic epithelia, and CDX1 gene expression is affected during colorectal tumour progression. In this study, real‐time quantitative RT‐PCR was used to investigate CDX1 expression in 26 colorectal carcinomas. Reduced expression of CDX1 was observed in 19 of 26 colon carcinomas compared to matched normal colonic mucosa: the decrease in CDX1 expression ranged between 0.10 and 0.79 (21–90% decrease; mean 64.75% ±22; p = 0.001). Mutation and loss of heterozygosity (LOH) analyses were then used to determine if reduced CDX1 expression was due to genetic alteration. No CDX1 gene mutations, but two known polymorphisms in exon 1, were observed. LOH was observed in 33% of the tumours investigated but this was not related to CDX1 expression. Since aberrant promoter methylation is a well‐known mechanism that participates in gene silencing, the methylation status of the CDX1 5′ CpG island promoter was also investigated. PCR amplification of bisulphite‐treated DNA followed by cloning was performed in 7 carcinomas that showed low expression of CDX1 and in 1 colonic carcinoma without reduced expression. Promoter hypermethylation occurred in carcinomas in which CDX1 reduced expression was present. These results suggest that CDX1 promoter hypermethylation is one of the molecular mechanisms that accounts for reduced CDX1 gene expression in colorectal carcinoma. Copyright © 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Modulation of dynamic release of vitamin B2 from a model pH‐sensitive terpolymeric hydrogel system
Authors: Bajpai SK , Dubey Seema
Published: September 2004

Terpolymeric devices consisting of acrylamide, methacrylamide and acrylic acid were synthesized and the release of the model drug riboflavin from these devices was studied at the physiological temperature 37°C. The gels exhibit a sharp pH‐dependent release behavior. The devices released nearly 42.2 ± 2.6% drug at pH 1.0 while nearly 95.3 ± 3.2% drug was released at pH 7.4. With increasing concentration of cross‐linker in the gel, the drug released was found to decrease. Moreover, with low content of cross‐linker a nearly zero‐order profile was obtained. The size of the cylindrical devices also affected the release kinetics and a linear dependency was observed between t1/2 (ie, the time required for 50 % release) and the square of the diameter, thus supporting the Tanaka–Fillmore theory. The molar ratio of acrylamide and methacrylamide also affected the dynamic release of riboflavin. It was found that variation in transit time could also affect the drug‐releasing capacity of the devices. Finally, the average and ‘late‐time’ diffusion coefficients for the gels having different initial loads were also evaluated. Copyright © 2004 Society of Chemical Industry
Statistical exploration of variation in quantitative two‐dimensional gel electrophoresis data
Authors: Gustafsson John S. , Ceasar Robert , Glasbey Chris A. , Blomberg Anders , Rudemo Mats
Published: September 2004

Two‐dimensional gel electrophoresis is a major technique in global analysis at the protein level. This paper presents an examination of spot volume data from three gel sets with radioactively labeled yeastSaccharomyces cerevisiaeproteins. A strong varianceversusmean dependence in data was found to be stabilized by applying a shifted logarithmic transformation. However, transformed data showed a remaining substantial variance heterogeneity for different proteins. Furthermore, examination of studentized residuals revealed that transformed data were approximately normally distributed and that there were spatial correlations among the measurement errors in the gel.
Proteomic analysis distinguishes basaloid carcinoma as a distinct subtype of nonsmall cell lung carcinoma
Authors: Li Long Shan , Kim Hyunki , Rhee Hwanseok , Kim Se Hoon , Shin Dong Hwan , Chung Kyung Young , Park Kang‐Sik , Paik Young‐Ki , Chang Joon , Kim Hoguen
Published: September 2004

The histopathologic type of lung cancer is known to be correlated with tumor behavior and prognosis. However, this classification is subjective and no specific molecular markers have been identified. The aim of this study was to identify protein markers in different types of nonsmall cell lung cancers. Two‐dimensional polyacrylamide gel electrophoresis analysis was performed with paired samples of three squamous cell carcinomas, three adenocarcinomas, four large cell carcinomas, and four basaloid carcinomas. We found that 25 proteins in 14 cases of lung cancer were differentially expressed compared to matched nontumorous lung tissues. Among these 25 proteins, 11 proteins were down‐regulated and 14 were up‐regulated in these four types of lung cancer. Alloalbumin venezia, selenium‐binding protein 1, carbonic dehydratase, heat shock 20KD‐like protein, and SM22 α protein were down‐regulated in all 14 cases of lung cancer examined, whereas alpha enolase was consistently up‐regulated. Supervised hierarchical cluster analysis based on the 25 differentially expressed proteins showed that basaloid carcinoma formed one independent group, whereas the other three cancer types were not uniquely classifiable. Our findings suggest that basaloid carcinoma is a unique subtype of nonsmall cell lung carcinoma.
Restoration of heat shock protein70 suppresses gastric mucosal inducible nitric oxide synthase expression induced by Helicobacter pylori
Authors: Yeo Marie , Park Hyun‐kyung , Kim Dong‐Kyu , Cho Sung Won , Kim Young Suk , Cho Sang Yun , Paik Young‐ki , Hahm Ki‐Baik
Published: September 2004

Heat shock proteins (HSPs) are crucial for the maintenance of cell integrity during normal cellular growth as well as during pathophysiological conditions. While functioning mainly as molecular chaperones, HSPs also appear to be involved in diverse biological activities, such as apoptosis, carcinogenesis, and cytoprotection from cytotoxic damage. Infection with Helicobacter pylori causes inflammation in the gastric mucosa, leading to gastritis, gastric ulcers, duodenal ulcer disease, and even gastric cancer, but the role of HSPs in H. pylori‐associated gastropathy is not known. Using two‐dimensional electrophoretic analysis, we have observed significant shifts in HSP profiles after H. pylori infection in RGM‐1 cells. We therefore evaluated the effect of treatments that induce HSPs on H. pylori‐induced inducible nitric oxide synthase (iNOS) expression. We found that H. pylori infection significantly attenuated the expression of HSP70, whereas exposure of cells to noncytotoxic heat shock or geranylgeranylacetone restored HSP70 expression, as well as suppressing the expression of iNOS, a major cause of H. pylori‐induced gastric tissue damage. Our results suggest that induction of HSP70 confers cytoprotection against H. pylori infection by inhibiting the expression of iNOS. In conclusion, these results provide important insights into the flux in HSPs profiles in response to H. pylori infection and highlight the cytoprotective role of HSP70 in H. pylori infection.
Lipid raft proteome reveals ATP synthase complex in the cell surface
Authors: Bae Tae‐Jung , Kim Min‐Sik , Kim Jun‐Woo , Kim Bong‐Woo , Choo Hyo‐Jung , Lee Joong‐Won , Kim Ki‐Bum , Lee Chang Seok , Kim Ji‐Hyun , Chang Sun Young , Kang Chang‐Yuil , Lee Sang‐Won , Ko Young‐Gyu
Published: September 2004

Since detergent‐resistant lipid rafts are involved in pathogen invasion, cholesterol homeostasis, angiogenesis, neurodegenerative diseases and signal transduction, protein identification in the rafts could provide important information to study their function. Here, we analyzed detergent‐resistant raft proteins isolated from rat liver by capillary liquid chromatography‐tandem mass spectrometry. Out of 196 proteins identified, 32% belonged to the raft or plasma membrane, 24% to mitochondrial, 20% to microsomal, 7% to miscellaneous, and 17% are unknown proteins. For example, membrane‐bound receptors, trimeric GTP‐binding proteins, ATP‐binding cassette transporters, and glycosylphosphatidylinositol‐anchored proteins were identified in this analysis. Unexpectedly, there were many mitochondrial proteins, raising a new issue for the presence of mitochondrial rafts or the localization of mitochondrial proteins into plasma membrane rafts. We confirmed that ATP synthase α and β were expressed on the surface of the plasma membrane in HepG2 hepatocytes by immunofluorescence, cell surface biotinylation, and cellular fractionation. They had two distinct biochemical properties, detergent insolubility and low density, suggesting that the ATP synthase complex might be located in plasma membrane rafts as well as in the mitochondria.
Profiling proteins related to amyloid deposited brain of Tg2576 mice
Authors: Shin Su Jeon , Lee Sung‐Eun , Boo Jung Hyun , Kim Mihyang , Yoon Young‐Dae , Kim Su‐il , Mook‐Jung Inhee
Published: September 2004

Alzheimer's disease (AD) is an age‐related neurodegenerative disorder that is characterized by the extracellular deposition of β‐amyloid and intracellular hyperphosphorylation of tau in the cortex and hippocampus of the brain. These characterizations are caused by abnormal expression, modification and deposition of certain proteins. Post‐translational modifications of proteins including oxidation and nitration might be involved in the pathogenesis of AD. In this study, AD‐related proteins were identified in the cortex of Tg2576 mice used as a model for studying AD. Tg2576 mice express high levels of the Swedish mutated form of human β‐amyloid precursor protein (APP) and generated high levels of β‐amyloid in the brains. Using Western blotting and two‐dimensional electrophoresis, proteins with differences in expression, oxidation and nitration in the cortex of Tg2576 mice brains were compared to littermate mice brains used as a control. The proteins with different expression levels were identified using matrix‐assisted laser desorption/ionization‐time of flight and liquid chromatography‐tandem mass spectrometry analyses. As a result, 12 proteins were identified among 37 different proteins using the PDQuest program. Furthermore, two proteins, laminin receptor and α‐enolase, were more susceptible to oxidative modification in the brains of Tg2576 mice compared to those of littermates. Similarly, α‐enolase, calpain 12, and Atp5b were more modified by nitration in brains of Tg2576 mice than those of littermates. Taken together, these proteins and their modifications may play an important role in the plaque deposition of Tg2576 mice brains.
Proteome analysis of rice blast fungus (Magnaporthe grisea) proteome during appressorium formation
Authors: Kim Sun Tae , Yu Seok , Kim Sang Gon , Kim Han Ju , Kang Sun Young , Hwang Du Hyeon , Jang Yu Sin , Kang Kyu Young
Published: September 2004

We used two‐dimensional gel electrophoresis (2‐DE) to identify the proteins that are induced in the rice blast fungus Magnaporthe grisea during appressorium formation. Proteins were extracted from conidia that had germinated on hydrophilic glass plates or from germinated and appressoria‐forming conidia on leaf wax‐coated hydrophobic glass plates after 4, 8, and 12 h of incubation. Differentially expressed protein spots during appressorium formation were confirmed from gels after 2‐DE analysis where proteins had been labeled with 35S methionine and stained with silver. Internal amino acid sequencing identified five proteins among several proteins induced during appressorium formation. Two denoted as M. grisea proteasome homolgues (MgP1 and MgP5) were 20S proteasome α subunits. The remaining three were scytalone dehydratase (SCD), and serine carboxypeptidase Y (CPY). None of the five have been reported previously in the rice blast fungus apart from SCD. We further investigated the role the α subunit of 20S proteasome plays in appressorium formation. We confirmed by Western blot analysis that MgP5 is highly expressed during appressorium formation and found that it is also markedly induced by nitrogen‐ and carbon‐starvation, in particular by the former. These observations suggest that the 20S proteasome may be involved in remobilizing storage proteins, which then help to build the appressorium. Thus, fungal proteome analysis may provide important clues about developmental changes such as the generation of the appressorium.
Analysis of proteome and transcriptome of tumor necrosis factor α stimulated vascular smooth muscle cells with or without alpha lipoic acid
Authors: Jang Won Gu , Kim Hye Soon , Park Keun‐Gyu , Park Yong Bok , Yoon Kun‐Ho , Han Seong‐Wook , Hur Seung‐Ho , Park Kyong Soo , Lee In‐Kyu
Published: September 2004

Vascular smooth muscle cells (VSMCs) play an important role in the development and progression of atherosclerosis. Tumor necrosis factor α (TNFα), a cytokine secreted by VSMCs and macrophages in atherosclerotic lesions, regulates a variety of cellular functions of inflammatory cells and VSMCs by promoting cell growth and motility, which are critical for the initiation and progression of vascularlesions. Alpha lipoic acid (ALA), a well known antioxidant, acts as a pyruvate dehydrogenase cofactor in mitochondrial metabolism. Recently, we reported that ALA has many beneficial effects on vascular cells in atherosclerosis. The aim of the current study was to examine VSMCs, treated for 24 hours with TNFα (10 ng/mL) in the presence or absence of ALA (2 mM), for differential protein and genes expression using two‐dimensional gel electrophoresis (2‐DE) and DNA microarray analysis, respectively. Using 2‐DE, we identified proteins whose expression changed by at least 2.5‐fold after TNFα stimulation. Proteins up‐regulated by TNFα that were subsequently down‐regulated in the presence of ALA were identified by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry as plasminogen activator inhibitor‐2, fetal liver LKB‐interacting protein, osteoblast‐specific factor 2, glucosidase II, cyclin‐dependent kinase 3, endoplasmin precursor and glutathione synthetase. TNFα down‐regulated proteins that were up‐regulated in the presence of ALA were keratin 19, eukaryotic translation elongation factor and Rho GDP dissociation inhibitor α. Gene expression analysis using DNA microarray tools confirmed the up‐regulation or down‐regulation of some, but not all, of the proteins observed in ALA challenged, TNFα‐treated cells. This data should provide valuable information about the underlying mechanisms of atherosclerosis.
Antigens secreted fromMycobacterium tuberculosis: Identification by proteomics approach and test for diagnostic marker
Authors: Bahk Young Yil , Kim Suk Am , Kim Ji‐Soo , Euh Hyung‐Jin , Bai Gil‐Han , Cho Sang‐Nae , Kim Yu Sam
Published: September 2004

Tuberculosis caused by mycobacteria, mainlyMycobacterium tuberculosis, is a major infectious disease of the respiratory system. An early diagnosis followed by chemotherapy is the major control strategy. In an effort to identify the antigens suitable for immunodiagnosis and vaccines, the proteins secreted in a culture medium from theM. tuberculosisK‐strain, which is the most prevalent among the clinical isolates in Korea and belongs to the Beijing family, were analyzed by two‐dimensional polyacrylamide gel electrophoresis (2‐D PAGE) and compared with those from theM. tuberculosisH37Rv and CDC1551 strains. Eight proteins, Rv0652, Rv1636, Rv2818c, Rv3369, Rv3865, Rv0566c, MT3304, and Rv3160, were identified by matrix‐assisted laser desorption/ionization‐time of flight‐mass spectrometry (MALDI‐TOF‐MS) or liquid chromatography‐electrospray ionization‐mass spectrometry (LC‐ESI‐MS) and found to be relatively abundant in the culture medium from theM. tuberculosisK‐strain but less so from the CDC1551 or H37Rv strains. In addition, Rv3874 (CFP‐10), Rv‐0560c and Rv3648c, which were expressed increasingly in the K and CDC1551 strains, were also identified using the same proteomics technology. All proteins were prepared by molecular cloning, expression inEscherichia colifollowed by affinity purification. Among them, three proteins, rRv3369, rRv0566c, and rRv3874, were selected by prescreening and examined for their potential as serodiagnostic antigens using an enzyme‐linked immunosorbent assay. When 100 sera from tuberculosis patients and 100 sera from the healthy controls were analyzed, rRV3369, rRv3874, and rRv0566c showed a sensitivity of 60%, 74%, and 43%, and a specificity of 96%, 97%, and 84%, respectively. These results suggest that the rRv3369 and rRv3874 proteins, which were expressed more abundantly in the more recently obtained clinical isolates ofM. tuberculosisthan in the laboratory‐adapted H37Rv strain, are promising for use in the serodiagnosis of tuberculosis.
Reactions of dimethoxycarbene with carbon–sulfur double bonds
Authors: Dawid Malgorzata , Reid Darren L. , Warkentin John , Mloston Grzegorz
Published: September 2004

Unlike electrophilic carbenes, which react at sulfur to produce thiocarbonyl ylide intermediates, dimethoxycarbene (DMC), generated by thermolysis of an oxadiazoline at 110°C in benzene in a sealed tube, reacts at carbon, possibly to generate a zwitterionic intermediate, or at both carbon and sulfur in a concerted process that generates a thiirane. In case of the strained 2,2,4,4‐tetramethylcyclobutane‐1,3‐dithione (2), an assumed zwitterion undergoes ring expansion. In analogous reactions, unstrained thiones afford thiiranes, possibly by ring closure of the postulated intermediates or by concerted addition. Desulfurization of thiiranes, which occurs spontaneously in some instances, results in the formation of ketene acetals, many of which hydrolyze during workup. O‐Alkyl thioesters and xanthates react to afford products via insertion of the DMC into C—O or C—S bonds, respectively. Copyright © 2004 John Wiley & Sons, Ltd.
The search for efficient intramolecular proton transfer from carbon: the kinetically silent intramolecular general base‐catalysed elimination reaction of O‐phenyl 8‐dimethylamino‐1‐naphthaldoximes
Authors: Asaad Nabil , Davies John E. , Hodgson David R. W. , Kirby Anthony J. , Vliet Liisa van , Ottavi Laura
Published: September 2004

The ready elimination of phenol/phenoxide from the O‐phenyl oxime 10E derived from 8‐dimethylamino‐1‐naphthaldehyde, necessarily involving proton transfer from carbon, is catalysed by the neighbouring NMe2 group at pH > 9. However, reaction is faster, rather than slower, at lower pH. It is shown that the step involving proton transfer is not cleanly rate determining at any pH: the preferred route involves syn/anti isomerization to form the more reactive Z‐isomer. The rate constant for the anti elimination cannot be extracted from the available data, so no reliable estimate of effective molarity (EM) is possible. Copyright © 2004 John Wiley & Sons, Ltd.
Dynamics and reactivity of chiral ion–dipole pairs
Authors: Speranza Maurizio
Published: September 2004

Modeling ionic reactions in a dynamic environment, such as in a solvent cage, requires the generation of tailor‐made ionic adducts involved in the process and the investigation of the intrinsic structural and electronic factors governing their behavior in the unsolvated state. A compendium of the most recent studies on the gas‐phase dynamics and reactivity of chiral ion–dipole pairs involved in classical organic reactions is reported, together with a presentation of the experimental and theoretical methodologies adopted. Copyright © 2004 John Wiley & Sons, Ltd.
Synthesis and characterization of new polystyrenes containing tributyltin moieties linked to the aromatic ring through a methylenic spacer
Authors: Angiolini Luigi , Caretti Daniele , Mazzocchetti Laura , Salatelli Elisabetta , Willem Rudolph , Biesemans Monique
Published: September 2004

Novel polymeric derivatives bearing tributyltin carboxylate moieties in the side chain were synthesized. The coordination at tin in solution and in the solid state was investigated by both Sn‐NMR and FT‐IR: the metal atom appears completely tetracoordinated in chloroform solution, while in the solid state all polymeric products exhibit both tetra‐ and pentacoordination at tin, the latter increasing with the amount of tin containing units. No evidence of tin leaching by hydrolysis of the organometallic ester was observed for these materials. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5372–5383, 2004
Structure and mechanical behavior of nylon‐6 fibers filled with organic and mineral nanoparticles. I. Microstructure of spun and drawn fibers
Authors: Ibanes C. , David L. , De Boissieu M. , Séguéla R. , Epicier T. , Robert G.
Published: September 2004

The crystalline structure and fibrillar texture of nylon‐6 fibers filled with nanosized particles were investigated using wide‐angle and small‐angle X‐ray scattering. As‐spun fibers filled with organic nanoparticles consisting of aromatic polyamide‐like hyperbranched molecules with amine‐terminating groups exhibited strong modification of both the molecular orientation and the crystalline structure compared with that of unfilled spun fibers. Montmorillonite‐filled fibers mainly exhibited orientation improvement. The differences are discussed in terms of the rheological and nucleating effects during spinning. Drawing at 140 °C involves structural changes that resulted in the three kinds of fibers having a similar crystalline form and molecular orientation. In parallel, after significant strain‐induced changes, the microfibrillar texture of the various fibers displayed subtle differences at the ultimate stage of drawing. The changes in the fibril long period and fibril radius as a function of draw ratio are discussed in terms of the two sequential deformation processes of microfibril stretching and microfibril slipping. The occurrence of interfibrillar strain‐induced cavitation is discussed in relation to the nature of the interactions between the filler and the nylon‐6 matrix. And, finally, the mechanical properties are discussed in relation to the filler–matrix interaction. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3876–3892, 2004
Determining the effects of vapor sorption in polymers with the quartz crystal microbalance/heat conduction calorimeter
Authors: Smith Allan L. , Mulligan Rose B. , Shirazi Hamid M.
Published: September 2004

The quartz crystal microbalance/heat conduction calorimeter (QCM/HCC) is a versatile instrument coupling both gravimetric and calorimetric techniques. The QCM/HCC is used to probe vapor sorption in thin films. Three parameters are measured simultaneously as a thin film undergoes vapor sorption, namely: mass changes in the film (±10 ng), corresponding thermal effects upon vapor sorption (±100 nW), and motional resistance (±0.5Ω) changes within the film. A range of film thicknesses (0.75 to 8.5 μm) of the polymer, Tecoflex™ are cast on QCMs and the interaction of each film with ethanol and water is determined. From the direct calorimetric measurements, sorption enthalpies (ΔsorptionH kJ/mol) are determined for the film–vapor interactions. Sorption isotherms are then analyzed for each film. The isotherms shown here generally display a linear Henry's Law dissolution relationship between the vapor pressure and the amount of vapor sorbed into the film. Motional resistance data provides a window to view viscoelastic effects of the polymer films upon vapor sorption. Motional resistance data are compared for ethanol sorption in a relatively thin (0.75 μm) and thicker (8.5 μm) Tecoflex™ film. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 3893–3906, 2004
Prediction of Carbonic Anhydrase Activation by Tri‐/Tetrasubstituted‐pyridinium‐azole Compounds: A Computational Approach using Novel Topochemical Descriptor
Authors: Bajaj Sanjay , Sambi S. S. , Madan A. K.
Published: September 2004

A novel highly discriminating adjacency‐cum‐distance based topochemical descriptor, termed as Superadjacency topochemical index, has been derived and its discriminating power investigated with regard to activation of Carbonic anhydrase (CA) isozyme‐I by tri‐/tetrasubstituted‐pyridinium‐azole compounds. The new index is not only sensitive to the presence of heteroatoms but also overcomes the problem of degeneracy of many topological descriptors. The discriminating power of Superadjacency topochemical index was found to be far superior when compared with that of distance based Wiener‘s index and adjacency based Molecular connectivity index. The values of Wiener‘s index, path‐one Molecular connectivity index and Superadjacency topochemical index of each of the 42 substituted‐pyridinium‐azole compounds comprising the dataset were computed. Resultant data was analyzed and suitable models developed after identification of the active ranges. Subsequently, a biological activity was assigned to each of the compounds involved in the dataset using these models, which was then compared with the reported activation constants for Carbonic Anhydrase isozyme‐I. Excellent correlations were observed between the activation constants of CA isozyme‐I and all the topological/topochemical descriptors. The overall accuracy of prediction was about 91% for models based upon both Molecular connectivity index as well as Wiener‘s index, and 96% for model based upon Superadjacency topochemical index. Surprisingly, the accuracy of prediction in the active range was found to be 100% in all the models. Thus the proposed index offers a vast potential for structure‐activity/structure‐property studies.
Ensembles in classical statistical mechanics and their unification via nonlinear field theory
Authors: Zakharov A. Yu
Published: September 2004

The connection between accessible volume of phase space for microcanonical ensemble and canonical partition function of complex temperature is established. Functional‐integral representation for both canonical and microcanonical ensembles in classical statistical mechanics is obtained. Random external field manifestation as interatomic potentials renormalization is derived. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Electronic excited states and stabilities of fullerenes: Isomers of C78 and Mg@C72
Authors: Slanina Zdenĕk , Uhlík Filip , Adamowicz Ludwik , Kobayashi Kaoru , Nagase Shigeru
Published: September 2004

There is one factor in relative stabilities of isomeric fullerenes that has rarely been studied so far—the contribution of excited electronic states. The contribution is clearly quantified by the electronic partition function, supposing the related excitation energies can be evaluated. As temperatures in fullerene synthesis are high, the term should be taken into account. In this article the problem is studied on two isomeric systems. One is the set of five isolated pentagon rule isomers of C78, relatively well known from experiments. The other is a model set of four isomers of Mg@C72 (not isolated yet). The electronic excitation energies are computed by the limited configuration interaction (CI) method. In the case of the C78 isomeric set, the ZINDO semiempirical method is used. Isomers of Mg@C72 are evaluated by means of the single‐excitation CI or CI‐singles (CIS) in the standard LanL2MB and LanL2DZ basis sets—CIS/LanL2MB and CIS/LanL2DZ. It is found that the electronic partition function can cause significant changes in the computed equilibrium relative concentrations of isomers at high temperatures. Metallofullerenes are more likely candidates for such enhanced effects. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Interatomic potential for the X1Σ state of Be2, revisited
Authors: Røeggen I. , Veseth L.
Published: September 2004

An extended geminal model has been applied to determine the interatomic potential for the X1Σ state of Be2. By adopting a (23s, 10p, 8d, 6f, 3g, 2h) uncontracted Gaussian‐type basis, the following spectroscopic parameters are obtained: Re = 4.633 a.u. (4.63 a.u.), De = 945 ± 15 cm (790 ± 30 cm), G(1)–G(0) = 221.7 cm−1 (223.8 ± 2 cm−1), G(2)–G(1) = 175.0 cm−1 (169 ± 3 cm−1), G(3)–G(2) = 123.1 cm−1 (122 ± 3 cm−1), and G(4)–G(3) = 80.8 cm−1 (79 ± 3 cm−1), experimental values in parentheses. The calculated binding energy is substantially higher than the accepted experimental value. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005
Critical angle and energy of DCS surface for e‐argon scattering
Authors: Paikeday Joseph M. , Ashley Brad T.
Published: September 2004

The differential scattering cross‐section (DCS) for electrons scattered elastically by Argon atoms is studied using a model potential. In the current study the long‐range polarization potential is represented by an energy‐dependent function in the form: Vp(E,r) = αd/[r + ξ(a,b,E)]4, and the short‐range part is constructed from the nonrelativistic Hartree–Fock wavefunction of the target atom in the form Vs(r) = (2Z/r)ΣnCnexp{−nCor}. Accurate phase shifts have been computed for angular momentum in the range 0 < ℓ < 13 from the Schrodinger equation and for 13 < ℓ < 1000 using the Born approximation. The computed DCS obtained using the approximate effective interaction potential for electrons scattered by the target atoms in their ground state is compared with available published results. In the current study the parameters contained in the energy‐dependent polarization potential are determined by the minimization of the DCS with respect to angle θ and the incident energy of E. The critical values of angle and energy (θc, Ec) are found to be (117.8°, 120.8 eV), (64.6°, 43.0 eV), and (141.2°, 40.7 eV). The resulting DCS in the angular range 2° < θ < 178° is found to be an improvement over earlier results and in better agreement with the available experimental data in the intermediate energy range. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Short‐range exchange‐correlation energy of a uniform electron gas with modified electron–electron interaction
Authors: Toulouse Julien , Savin Andreas , Flad Heinz‐Jürgen
Published: September 2004

We calculate the short‐range exchange‐correlation energy of the uniform electron gas with two modified electron–electron interactions. While the short‐range exchange functionals are calculated analytically, coupled‐cluster and Fermi‐hypernetted‐chain calculations are carried out for the correlation energy and the results are fitted to an analytical parametrization. These data enable us to construct the local density approximation corresponding to these modified interactions. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
Reactions of ·OH with thymine studied using density functional theory
Authors: Ji Yanju , Xia Yueyuan , Zhao Mingwen , Li Feng , Huang Boda
Published: September 2004

We studied three possible reactions of a free ·OH radical with thymine by using density functional theory calculations. The results indicate that there is no energy barrier in the reactions of a free ·OH radical adding to the C6 position of thymine, while the reactions of a free ·OH radical adding to the C5 position of thymine and the reaction of an ·OH abstracting a hydrogen from the C5 methyl group should overcome the energy barriers of ∼0.70 kcal/mol and ∼1.88 kcal/mol, respectively. The C6‐hydroxylated radical formed is energetically more favorable than the C5‐hydroxylated radical. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005