bluuebunny/crossref_metadata_2025 huggingface dataset:
Frontline: Interferon regulatory factor‐1 as a protective gene in intestinal inflammation: role of TCR γ δ T cells and interleukin‐18‐binding protein
Authors: Siegmund Britta , Sennello Joseph A. , Lehr Hans A. , Senaldi Giorgio , Dinarello Charles A. , Fantuzzi Giamila
Published: July 2004

The transcription factor IFN regulatory factor‐1 (IRF‐1) regulates production and activity of many inflammatory mediators and cells. Here, we investigated the role of IRF‐1 in intestinal inflammation using clinical and histologic scores; inflammatory mediators were also measured in colonic tissue. Dextran sulfate sodium (DSS) or trinitrobenzene sulfonic acid (TNBS) was administered to wild‐type (WT) or IRF‐1 knockout (KO) mice. DSS or TNBS led to a dramatic increase in lethality and colitis severity in IRF‐1 KO compared with WT mice. Reduced levels of IFN‐γ and IL‐18‐binding protein (IL‐18BP) were observed in the colon of IRF‐1 KO mice, whereas levels of inducible nitric oxide synthase, cyclooxygenase‐2, phosphorylated STAT‐3, chemokines, TNF‐α, IL‐1β, IL‐15, and IL‐18 were not significantly changed. Intestinal inflammation was not altered in IFN‐γ KO mice or in WT mice given neutralizing anti‐IFN‐γ antibodies, but was increased in mice lacking TCR γ δ lymphocytes, a population significantly decreased in the intestine of IRF‐1‐deficient mice. Administration of IL‐18BP reversed the increased susceptibility of IRF‐1 KO mice to DSS. These results suggest a protective role for IRF‐1 in intestinal inflammation, with a possible anti‐inflammatory and/or restorative role. IL‐18BP and TCR γ δ cells appear to be critical factors inthe anti‐inflammatory effects of IRF‐1.

See accompanying article http://dx.doi.org/10.1002/eji.200425351
Integration and independent acquisition of specialized skin‐ versus gut‐homing and Th1 versus Th2 cytokine synthesis phenotypes in human CD4+ T cells
Authors: Colantonio Lucia , Rossi Barbara , Constantin Gabriela , D'Ambrosio Daniele
Published: July 2004

CD4+ T helper cells are heterogeneous in terms of tissue‐specific homing and cytokine synthesis phenotypes. The mechanisms for the acquisition of tissue‐specific homing phenotypes and their relationship with the attainment of polarized cytokine synthesis profiles of T cells are critically important but poorly understood. Here, we analyze the coordinate acquisition of Th1 versus Th2 cytokine (IFN‐γ vs. IL‐4) and skin‐ versus gut‐homing (CLA vs. integrin β7) phenotypes in human CD4+ T cells. We show that the acquisition of skin‐ versus gut‐homing T cell phenotypes is independent of Th1 versus Th2 cell fate determination and that it occurs in relation to cell cycle progression following instructive mechanisms and distinct kinetics. Expression of chemokine receptors CXCR3 and CCR4 correlates with the acquisition of Th1 versus Th2 rather than skin‐ versus gut‐homing phenotypes. These findings, together with the skewed overlap observed in vivo between CLA vs. integrin β7 and IL‐4 vs. IFN‐γ expression, suggest a novel interpretation to the complex patterns of chemokine receptor expression on memory T cells.
Group 4 Complexes of Chelating Dianionic [OSO] Binaphtholate Ligands; Synthesis and Alkene Polymerisation Catalysis
Authors: Natrajan Louise S. , Wilson Claire , Okuda Jun , Arnold Polly L.
Published: July 2004

Mono‐ and bis(ligand)titanium and ‐zirconium complexes of a sulfur‐bridged binaphtholate [1,1′‐S(2‐HOC10H4‐tBu2‐3,6)2] (H2LSN) have been synthesised and characterised. Complexes of the general form [M(LSN)X2] (X = Cl, CH2Ph) are prepared by protonolysis or metathesis. X‐ray crystallographic structural characterisation of the dibenzyl complex [Zr(LSN)(CH2Ph)2] is reported, as well as the structure of its partially oxidised derivative [Zr(LSN)(CH2Ph)(OCH2Ph)]2. Complexes of the form [M(LSN)2] are readily formed; these can be converted by comproportionation reactions into the mono‐LSN derivatives above. The X‐ray crystal structure of a bis(sulfur‐bridged biphenolate) is presented. The representative complexes have been tested as alkene polymerisation catalysts, in conjunction with a methylalumoxane cocatalyst, and for the first time a zirconium complex of a sulfur‐bridged biphenolate‐type ligand has been found to be active in the polymerisation of ethene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Clonal diversity and subpopulation structure in central European relict populations ofSaxifraga paniculataMill.(Saxifragaceae)
Authors: Reisch C. , Poschlod P.
Published: July 2004

Saxifraga paniculatais a rare and endangered glacial relict in central Europe. It shows high clonal reproduction. In this study, we analysed the clonal diversity and the subpopulation structure of three populations from the species main distribution area in Germany outside of the Alps (Swabian Alb, Black Forest, Nahe Mountains). We used RAPD analysis to detect the genetic variation inS. paniculataand found high levels of clonal diversity. The percentage of distinguishable genotypes (PD) within populations ofS. paniculatawas 1.0 and even spatially well defined mats of rosettes consisted of several genotypes. In a cluster analysis, the investigated populations were clearly separated from each other. However, we detected no genetic differentiation among subpopulations. We ascribe the high level of genotypic variability to the species' mixed mating system, which creates and maintains high levels of genetic diversity within the populations ofS. paniculata. Clonal reproduction seems, meanwhile, to be of secondary importance for the propagation of the species. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recolonisation of natural landslides in tropical mountain forests of Southern Ecuador
Authors: Ohl C. , Bussmann R.
Published: July 2004

The regeneration of the vegetation of natural landslides was studied at Estación Científica San Francisco (ECSF) in a tropical mountain forest area of Southern Ecuador, north of Podocarpus National Park. The study focused on the process of regeneration on natural landslides and the vegetation change along an altitudinal gradient using space‐for‐time substitution. The most important plant families present on the landslides during the first stages of succession are Gleicheniaceae (Pteridophyta), Melastomataceae, Ericaceae and Orchidaceae. Species of the genus Sticherus (Gleicheniaceae) are dominant, and species composition varies with altitude and soil conditions. Colonisation of landslides is not homogeneous. Zones with bare ground, sparsely vegetated patches and densely covered areas may be present within the same slide. This small scale spatial heterogeneity is often created by local ongoing sliding processes and different distances towards undisturbed areas. Therefore, the duration of the successional process is highly variable. The initial stage of the succession is a community of non vascular plants interspersed with scattered individuals of vascular plants. By means of runner‐shoots they form vegetation patches which start growing into each other. The second stage is dominated by Gleicheniaceae (species composition varying in altitude and soil chemistry). In the third stage, bushes and trees colonise, sheltered by the ferns, and a secondary forest develops with pioneer species that are not found in the primary forest vegetation. The common phenomenon of the natural landslides leads to an increase in structural and species diversity on a regional scale. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High sensitivity of chemiluminescent methodology for detection of clonal CDR3 sequences in patients with acute lymphoblastic leukemia
Authors: Leal E. , Jaloma‐Cruz A. R. , Barros‐Núñez P.
Published: July 2004

Detection of minimal residual disease (MRD) in patients with B‐cell acute lymphoblastic leukemia (B‐ALL) has been achieved using several radioactive labelling methodologies; however, limited information exists about the use of chemiluminescent labelling. Although many malignant disorders are related to cytogenetic alterations, there is not a consistent chromosomal translocation that could serve as a tumour marker for the monitoring of MRD. ALL are derived from B‐lymphocytes in 80% of cases. In the early stages of their maturation, the immunoglobulin heavy chain genes (IgH) undergo rearrangements among their V, D, and J segments, giving rise to the Complementary Determining Regions (CDR). Among these, CDR3 is considered unique for each lymphocyte and used as a tumour‐specific marker in B‐ALL patients. In this study, the CDR3 was labelled with digoxigenin and used as a patient‐specific probe to test its sensitivity for further detection of MRD. Fourteen pretreatment samples of bone marrow (BM) or peripheral blood (PB) from B‐ALL patients were included. Tumour‐specific probes were designed from each clonal product by elimination of the consensus sequences. Ten digoxigenin‐labelled probes were hybridized with a mixture of their respective clonal DNA and the polyclonal product from a normal healthy donor, in serial dilutions from 1:1 up to 1:107. A sensitivity range of 1:103–1:106 was obtained, with an average of 1:105. Crossed tests performed in four patients, showed right probe specificity in all cases. We propose that the design of allele‐specific probes with chemiluminescent labelling, represents a reliable, sure and sensitive alternative methodology for MRD detection in patients with B‐cell lymphoproliferative disorders. Copyright © 2004 John Wiley & Sons, Ltd.
Bone formation and bioresorption after implantation of injectable β‐tricalcium phosphate granules–hyaluronate complex in rabbit bone defects
Authors: Chazono Masaaki , Tanaka Takaaki , Komaki Hirokazu , Fujii Katsuyuki
Published: July 2004

The objective of this study was to evaluate the effects of a complex of β‐tricalcium phosphate (β‐TCP) granules and 3.5% hyaluronate (β‐TCP granules–HY complex) compared with a β‐TCP block, in terms of osteoconductivity and biodegradability, to determine whether this complex would be a good candidate for bone void filler. Both materials were implanted into cavities drilled in rabbit femoral condyles. New bone formation and mineral apposition rate were evaluated to analyze osteoconductivity, whereas residual β‐TCP within the defects and tartrate‐resistant acid phosphatase (TRAP) cellular activity were studied for β‐TCP resorption. The results show that both the β‐TCP block and the β‐TCP granules–HY complex support bone ingrowth; however, bioresorption was rapid for β‐TCP granules–HY but weak for β‐TCP block. This biodegradation mechanism was considered to be a cell‐mediated disintegration by numerous TRAP‐positive giant cells. The time lag between the peak value of TRAP‐positive giant cell population and that of new bone formation rate suggests that a coupling‐like phenomenon could be occurring in the β‐TCP‐filled bone defects. In addition, β‐TCP granules–HY complex, which is an injectable, pastelike material, has similar osteoconductive properties to β‐TCP block. Thus, this complex may be useful as a bone filler in clinical application. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 542–549, 2004
Evaluation of in vivo biocompatibility and biodegradation of photocrosslinked hyaluronate hydrogels (HADgels)
Authors: Miyamoto Kenji , Sasaki Masanori , Minamisawa Yuka , Kurahashi Yasuhiro , Kano Hiroki , Ishikawa Shin‐ichi
Published: July 2004

HADgels are newly developed photocrosslinked hyaluronate hydrogels. They are produced from an aqueous solution of a hyaluronan derivative (HAD) in which cinnamic acid is introduced into the carboxyl moiety of hyaluronan using 3‐aminopropanol as a spacer. High‐energy ultraviolet irradiation of the HAD solution induces photodimerization of cinnamic acid, resulting in the development of a macromolecular network of each hyaluronan to water‐insoluble hydrogels. The biocompatibility and biodegradation of HADgels were evaluated by guinea pig intracutaneous injection testing for up to 28 days. By macroscopic and histological observations, HADgels showed good tissue compatibility and did not induce excess inflammation at the injection sites. Biodegradation of the HADgels clearly depended on the degree of crosslinking at the fixed weight concentrations of HAD (0.5% and 1.0%). In addition, serum analyses showed that the injected guinea pigs did not produce specific antibodies against HADgels. These results indicate that HADgels have preferable biocompatibility and can be used as a new class of injectable, absorbable biomaterial, especially for preventing postsurgical adhesion formations. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 550–559, 2004
Regulation of histone deacetylase activities
Authors: Sengupta Nilanjan , Seto Edward
Published: July 2004

Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from lysine residues in both histone and non‐histone proteins. They play a key role in the regulation of gene transcription and many other biological processes involving chromatin. Significantly, recent studies suggest that HDACs are critically involved in cell‐cycle regulation, cell proliferation, differentiation, and in the development of human cancer. HDAC inhibitors currently are being exploited as potential anti‐cancer agents. As expected for vital regulators of many cellular processes, the activities of HDACs are tightly controlled and precisely regulated by multiple mechanisms. The activities of most if not all HDACs are regulated by protein–protein interactions. In addition, many HDACs are regulated by post‐translational modifications as well as by subcellular localization. Less studied, but perhaps equally important, is the regulation of some HDACs by control of expression, availability of cofactors, and by proteolytic processing. A complete understanding of how HDACs are regulated will contribute not only to our overall knowledge of chromatin structure and gene control, but will offer tremendous insight into approaches for developing therapeutic HDAC inhibitors with improved specificity. © 2004 Wiley‐Liss, Inc.
Synthesis and biodistribution in mice of a new 99mTc nitrido complex for brain imaging
Authors: Zhang Junbo , Wang Xuebin , Liu Jing
Published: July 2004

The bis(N‐cyclopentyl dithiocarbamato) nitrido technetium‐99m complex 99mTcN(CPEDTC)2 was synthesized by the reduction of 99mTcO into [99mTc≡N]2+ with stannous chloride in the presence of succinic dihydrazide and propylenediamine tetraacetic acid, followed by the addition of sodium N‐cyclopentyl dithiocarbamate monohydrate. The radiochemical purity (RCP) of the product was over 90% as measured by thin layer chromatography(TLC) and high performance liquid chromatography(HPLC). In vitro studies showed that the complex possessed good stability under physiological conditions. Its partition coefficient studies indicated it was a good lipophilic complex. The electrophoresis results showed the complex was neutral. The biodistribution results in mice indicated that 99mTcN(CPEDTC)2 was significantly retained into the brain. The brain uptake(ID%/g) was 3.58, 5.26, 3.73 and 2.72 and the brain/blood ratios were 0.79, 1.69, 1.59 and 1.58 at 5, 30, 60 and 90 min post‐injection, respectively. These results suggested potential usefulness of the complex as a new brain perfusion imaging agent. Copyright © 2004 John Wiley & Sons, Ltd.
The vascular response induced by transmyocardial laser revascularization is determined by the size of the channel scar: Results of CO2, holmium and excimer lasers
Authors: Huikeshoven Menno , Beliën Jeroen A.M. , Tukkie Raymond , Beek Johan F.
Published: July 2004

Background and Objectives

To investigate the angiogenic effect of CO2, Ho:YSGG, and XeCl excimer TMLR in a rat model with morphologic characteristics of chronic myocardial ischemia.

Study Design/Materials and Methods

Two channels (200–320 μm) were created per rat heart. After 14 days, vessel numbers and densities in and around laser scars were assessed.

Results

Capillary densities in the laser scars were equal between the three lasers (∼130 vessels/mm2) but much lower than in control areas (∼2,100 vessels/mm2). Vessel densities excluding capillaries were significantly higher in Ho:YSGG and CO2 scars compared to excimer scars, while only Ho:YSGG scars contained significantly more large vessels (diameter ≥ 20 μm) than control areas. Only rarely, extension of vascular growth into adjacent myocardium was observed in any of the three groups.

Conclusions

These results indicate that the angiogenic response following TMLR is limited to the channel scar and related to the scar size rather than the specific laser type. Lasers Surg. Med. 35:35–40, 2004. © 2004 Wiley‐Liss, Inc.
Synthesis of Well‐Defined Hybrid Macromonomers of Poly(ethylene oxide) and Their Reactivity in Photoinitiated Polymerization
Authors: Du Juan , Murakami Yoshitaka , Senyo Takamichi , Adam  , Ito Koichi , Yagci Yusuf
Published: July 2004

Summary: α,ω‐Hybrid (hetero‐telechelic) poly(ethylene oxide) (PEO) macromonomers carrying both cationic and radical or anionic polymerizable vinyl end groups were newly synthesized by the living anionic polymerization of ethylene oxide (EO) initiated with partially K‐alkoxidated vinylic alcohols such as the monovinyl ether of tetramethylene glycol or di(ethylene glycol) and p‐vinylbenzyl alcohol (VBA), followed by reaction with methacryloyl chloride (MAC). They possess a couple of α‐ and ω‐end groups that can polymerize concurrently or selectively by radical and/or cationic or anionic mechanism. The reactivity of the radical and cationic species formed upon photolysis of benzophenone and triphenylsulfonium tetrafluoroborate towards these end groups were studied by means of 1H NMR analysis following the disappearance of the respective olefinic groups. Studies with macromomonomers and model compounds revealed that photoexcited benzophenone abstracts hydrogen atoms from the PEO backbone to form radicals without added hydrogen donors. In the case of the sulfonium salt, both radical and cationic species are formed, which react with the respective functional groups. It was also shown that vinyl ether moieties react more readily than the methacrylate in both radical and cationic processes.

The general synthetic strategy followed for the preparation of the hybrid PEO macromonomers studied here.

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The general synthetic strategy followed for the preparation of the hybrid PEO macromonomers studied here.
Enthalpy of Swelling of Potassium Polyacrylate and Polymethacrylate Hydrogels. Evaluation of Excluded‐Volume Interaction
Authors: Safronov Alexander P. , Smirnova Yelena A. , Pollack Gerald H. , Blyakhman Felix A.
Published: July 2004

Summary: The enthalpy of swelling over the entire concentration range in potassium polyacrylate and polymethacrylate hydrogels with varying charge density was measured by means of isothermal Calvet microcalorimetry at 298 K. Concentration plots of the enthalpy of swelling at polymer volume fractions up to 50% were used for evaluation of Flory‐Huggins binary parameter of interaction. Apparent values of χ determined directly from experimental plots revealed extremely strong concentration dependence at high degrees of swelling. This was taken as evidence for the overlap of electrostatic and excluded‐volume interactions. The separate evaluation of these contributions to the enthalpy of swelling was performed using the recent theory developed for the enthalpy of dilution in semi‐dilute polyelectrolyte solutions. The mean value of the parameter χ over a wide range of swelling for the uncharged poly(acrylic acid) and poly(methacrylic acid) gel was found equal to 0.21 and −0.50 respectively. The ionization of the gel network due to the introduction of potassium salt residues resulted in the progressive decrease in the quality of the solvent. At 40–50% of ionization, the binary interaction parameter was about 2.8 both for potassium polyacrylate and polymethacrylate hydrogels. That value is much more than the critical value for liquid‐liquid phase separation in non‐electrolyte polymer solutions.

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Saccharide Polymers 6
Authors: Boltres Daniela , Schmalbruch Bodo , Buchholz Klaus
Published: July 2004

Summary: The 2,4,6‐tri‐O‐acetyl‐3‐deoxy‐D‐erythro‐hex‐2‐enono‐1,5‐lactone, briefly Ac‐Gluc‐enlactone (GEL) (1), is easily synthesized in an one‐step reaction from glucono‐δ‐lactone with good yields. Free radical polymerizations of GEL with vinyl esters with side chain of different length including fatty acids esters were carried out in substance or in solution under various conditions. The structures and chemical compositions of the polymers were established by elemental analysis, FT‐IR‐, 1H‐, and 13C NMR spectroscopy. Copolymerization kinetics were investigated. Characteristic properties of polymers, e.g. molecular weight, optical rotation, and thermal properties are reported. The products are of interest as components in commodities with binding and adhesive properties.

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BASF on Campus
Authors: Schädler Volker
Published: July 2004

Macromolecular News: This section contains news of the macromolecular community all over the world. Articles about, for example, people, projects, and market trends are welcome. Suggestions should be sent to the editorial office of the Macromolecular journals, preferably by E‐mail to macromol@wiley‐vch.de. The editorial office decides which articles will be published.
Temperature‐sensitive defects in paramyotonia congenita mutants R1448C and T1313M
Authors: Dice Margaret S. , Abbruzzese Jennifer L. , Wheeler James T. , Groome James R. , Fujimoto Esther , Ruben Peter C.
Published: July 2004

The biophysical origins of paramyotonia congenita and its exacerbation in cold temperatures were examined. Human skeletal muscle voltage‐gated sodium channels were expressed in Xenopus oocytes and macroscopic currents were recorded from cell‐attached patches. Wild‐type (hNaV1.4) channels were compared to two mutant channel isoforms, T1313M and R1448C. The voltage dependence and temperature sensitivity of activation, fast‐inactivation onset and recovery, and deactivation were studied. Although activation and the onset of fast‐inactivation were temperature sensitive in all three isoforms, and although these properties in mutant channels differed from those in wild‐type channels, they did not account for cold‐exacerbation. Deactivation, however, was disproportionately slower in R1448C, but not in T1313M, than in hNaV1.4. These defects may, at least in part, account for the clinical symptoms of paramyotonia congenita and its exacerbation by cold, and provide a basis for studies into the therapeutic alleviation of these symptoms. Muscle Nerve 30: 277–288, 2004
Diabetic amyotrophy progressing to severe quadriparesis
Authors: Taylor Bruce V. , Dunne John W.
Published: July 2004

Diabetic amyotrophy is a distinctive form of diabetic neuropathy usually characterized by the abrupt onset of pain and asymmetric proximal leg weakness and wasting. Involvement of the upper limbs is unusual, and prognosis is said to be good. We describe two patients, each with type II diabetes mellitus, who presented with diabetic amyotrophy progressing to severe quadriparesis. One patient remains severely disabled. The clinical spectrum of diabetic amyotrophy includes progression to severe quadriparesis. Muscle Nerve 30: 505–509, 2004
Cytoskeletal myotoxicity from simvastatin and colchicine
Authors: Baker Steven K. , Goodwin Susan , Sur Monalisa , Tarnopolsky Mark A.
Published: July 2004

We report the case of a 79‐year‐old man with mild chronic renal failure who developed severe rhabdomyolysis after combined exposure to simvastatin and colchicine. Colchicine induces myopathy through disruption of microtubular function with subsequent vacuolization and pseudomyelinic body accumulation. Statin therapy is associated with myonecrosis, membranous myeloid bodies, and vacuolization, presumably as a function of impaired isoprenoid metabolism. Vesicle trafficking requires small G‐protein prenylation and statins can disrupt cytoskeletal integrity. We propose that synergistic cytoskeletal myotoxicity may account for the extreme elevation of serum creatine kinase not previously reported in pure colchicine myopathy. Muscle Nerve, 2004
A comparative study of knowledge about and attitudes toward the combined oral contraceptives among Korean and Japanese university students
Authors: Lim Hyun‐Ja , Lee Myeong Soo , Cho Yoo‐Hyang , Kazumi Uchiyama
Published: July 2004

Purpose

To compare university students' knowledge about and attitudes toward the combined oral contraceptives (COC) in two countries with different pharmaceutical systems (Japan and Korea), and to explore the reasons limiting the use of the COC in these populations.

Methods

University students in Korea and Japan completed a questionnaire containing a total of 55 questions about the students' demographics (8 questions), knowledge about the COC (15 questions), attitudes toward the COC (24 questions) and the reasons for limited use of the COC among the population (8 questions).

Results

Male students' attitudes toward the COC were significantly more positive than those of female students in Korea, but not in Japan. Knowledge about and attitudes toward the COC did not differ significantly between the two countries. The age at which students desired to use the COC was significantly correlated with age in both countries. There were significant correlations between knowledge about and attitude towards the COC in both countries and between age and attitude towards the COC in Japan. In both countries, the most commonly cited reasons for limited use of the COC were concern about adverse side effects.

Conclusions

These results confirm the need to develop appropriate sex education programs in Korea and Japan. Cultural differences and differences in the pharmaceutical and medical systems between the two countries should be considered when designing sex education programs for young people in Korea and Japan. Copyright © 2004 John Wiley & Sons, Ltd.
EVOH/clay nanocomposites produced by dynamic melt mixing
Authors: Artzi N. , Narkis M. , Siegmann A.
Published: July 2004

Ethylene‐vinyl alcohol copolymer (EVOH)/clay nanocomposites were prepared via a dynamic melt‐intercalation process using a Brabender Plastograph or extruder. The phase morphology and the crystallization behavior of the nanocomposites were investigated, using differential scanning calorimetry (DSC), X‐ray diffraction (XRD), and transmission electron microscopy (TEM). Mechanical properties were determined using an Instron machine. It was found that the viscosity of EVOH/clay mixtures increases with processing time. Thermal analysis of the EVOH/clay nanocomposites showed that the melting temperature, crystallization temperature, and heat of fusion of the EVOH matrix sharply decrease when clay is added. XRD verified an increased gallery height for the clay in the composites. Maleic anhydride–grafted ethylene vinyl acetate (EVA‐g‐MA) or maleic anhydride–grafted linear low‐density polyethylene (LLDPE‐g‐MA) were added as compatibilizers of EVOH with clay, in various concentrations (1, 5 and 10 wt%). Significantly higher viscosity levels were obtained for the compatibilized systems as the torque dramatically increased when processed in the Brabender machine. Enhanced intercalation within the galleries was obtained. EVOH crystallinity decreased with increasing compatibilizer content, until at a certain content no crystallization took place. EVOH/clay composites were also processed in an extruder, showing improved mechanical properties for as low as 1 wt% clay. The strong EVOH/clay interactions are responsible for the unique behavior of their nanocomposites. Polym. Eng. Sci. 44:1019–1026, 2004. © 2004 Society of Plastics Engineers.
Cure kinetics of epoxy systems modified with block copolymers
Authors: Larrañaga M , Martín MD , Gabilondo N , Kortaberria G , Corcuera MA , Riccardi CC , Mondragon I
Published: July 2004

The kinetics pathway of a 4,4′‐diaminodiphenylmethane‐cured diglycidyl ether of bisphenol‐A (DGEBA) epoxy system modified with a PEO–PPO–PEO block copolymer has been investigated by differential scanning calorimetry. The curing progress of this system has also been studied by dielectric relaxation spectrometry following changes in the main α‐relaxation. An interesting finding is the change in rate constant with copolymer content. Infrared spectroscopy shows that this change is due to interactions between the hydroxyl groups of the growing epoxy thermoset and the ether bonds of the block copolymer. The proposed phenomenological autocatalytic model provides a good description of the cure behaviour of this epoxy/copolymer system for all cure cycles used. Copyright © 2004 Society of Chemical Industry
Electric self‐heating behavior of acetylene carbon black filled high‐density polyethylene composites
Authors: Song Yihu , Zheng Qiang
Published: July 2004

The electric self‐heating behavior of carbon black (CB) filled high‐density polyethylene (HDPE) was studied in relation to the time‐dependent current and surface temperature under various voltages and to the voltage‐dependent surface temperature at electric–thermal equilibrium. The resistance increase due to self‐heating restricts the current flow through the sample and thus stabilizes the electric power and the self‐heating temperature to their saturation values, which vary with the voltage. A simple phenomenological model shows that self‐heating at electric‐thermal equilibrium is involved in the initial resistance, the electric field induced positive temperature coefficient (PTC) transition and the heat dissipation. The influences of annealing and irradiation crosslinking on the self‐heating behavior are discussed. Copyright © 2004 Society of Chemical Industry
Urea and formamide as a mixed plasticizer for thermoplastic starch
Authors: Xiaofei Ma , Jiugao Yu , Jin Feng
Published: July 2004

Mixtures of urea and formamide were tested as plasticizers for thermoplastic starch (TPS). The hydrogen bonding interactions between urea/formamide and starch were investigated by using Fourier‐transform infrared spectroscopy (FT‐IR). The thermal stability, mechanical properties and starch retrogradation behavior were also studied by thermogravimetric analysis (TGA), tensile testing and X‐ray diffraction (XRD), respectively. TPS plasticized by urea (20 wt%) and formamide (10 wt%) showed better thermal stability and water resistance than conventional TPS plasticized by glycerol. Moreover, the tensile stress, strain and energy at break, respectively, reached 4.83 MPa, 104.6 % and 2.17 N m after storing in an atmosphere of relative humidity (RH) of 33 % for one week. At the same time, this mixed plasticizer could effectively restrain the retrogradation of starch. Copyright © 2004 Society of Chemical Industry
Fast, contactless and spatially resolved measurement of sheet resistance by an infrared method
Authors: Isenberg Joerg , Biro Daniel , Warta Wilhelm
Published: July 2004

The principle of free carrier absorption in combination with a CCD camera sensitive in the infrared is used to establish a measurement method for the emitter sheet resistance of silicon solar cells. This combination allows for extremely fast measurements. For example a 100 × 100 mm wafer may be measured with a spatial resolution of 350 μm within less than 10 s.

An additional advantage of the optical measurement of emitter sheet resistance is the ability to measure inhomogeneities with an extremely good spatial resolution without errors due to size and orientation of the probe, which occur regularly in electrical measurements as, e.g., four‐point probing if a spatial resolution of the order of or below the size of the probe is required. In the set‐up presented spatial resolutions as low as 50 μm were realized, but even higher resolutions would be attainable with an appropriate lens system. The measurement requires a solar cell precursor after emitter diffusion, but before metalization. Additionally a reference without emitter, but with identical surface properties is needed.

The high spatial resolution facilitates a detailed investigation of selective emitters and a comparison of the results obtained by four‐point probing. It is shown that the method developed here allows a considerably better quantitative evaluation of these structures than electrical measurements. Additionally the technique is used to test and optimize the homogeneity of a diffusion furnace. Copyright © 2004 John Wiley & Sons, Ltd.
Childhood‐onset schizophrenia: An overview
Authors: Gonthier Misty , Lyon Mark A.
Published: July 2004

Childhood‐onset schizophrenia (COS), particularly when diagnosed prior to the age of 13, is considered to be especially rare and severe. This article provides an in‐depth look into its symptomatology, general course, long‐term functioning, diagnostic criteria, and methods of assessing the disorder. It also includes discussions of the various treatments used with patients having COS, including psychopharmalogical treatments, cognitive therapy, family interventions, educational interventions, and environmental manipulations. Particular attention is paid to the educational implications of the disorder and the role of school psychologists in working with this population. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 803–811, 2004.
Crisis prevention and intervention: A survey of school psychologists
Authors: Nickerson Amanda B. , Zhe Elizabeth J.
Published: July 2004

A random sample of 197 practicing school psychologists who were members of the National Association of School Psychologists (NASP) completed a survey questionnaire on experiences and perceptions with regard to school crisis preparedness, prevention, and intervention. Respondents indicated having the most direct experience with student–student physical assaults, serious illness or injury of students, unexpected students deaths, suicide attempts, and guns or other weapons at school. School psychologists reported that their schools used a wide variety of prevention and intervention strategies, most of which have been advocated in the literature. Respondents reported being most involved in the implementation of crisis prevention and intervention strategies and less involved in development and evaluation. Results and implications are discussed within the context of empirically supported practices and school psychologists' readiness to assume larger roles in crisis prevention and intervention. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 777–788, 2004.
The early assessment conundrum: Lessons from the past, implications for the future
Authors: Bordignon Catherine M. , Lam Tony C.M.
Published: July 2004

The early childhood educational field has garnered attention with initiatives to foster skill acquisition in young children prior to kindergarten entry. These initiatives, in conjunction with the rigorous demands of curricular reform and a burgeoning accountability movement, invoke questions regarding the adequacy of the instruments used to assess young children and the inherent difficulties in conducting such assessments. Because the effectiveness of education relies critically on the sound diagnoses of children's readiness for learning and the measurement of their subsequent progression throughout the schooling process, critical issues in early assessment must be addressed. An examination of past practices was synthesized with recent research to focus awareness on the insufficient content domain, restrictive context, adverse timing and questionable psychometric properties, specifically the inappropriate norms and low predictive validity, of many instruments. Both the implications of and compensatory strategies for each issue are considered. © 2004 Wiley Periodicals, Inc. Psychol Schs 41: 737–749, 2004.
Syntheses of bisazo‐containing polymethacrylates using atom transfer radical polymerization and the photoalignment behavior
Authors: Jin Ming , Xin Yang Qing , Lu Ran , Hua Xu Ting , Ying Zhao Ying
Published: July 2004

Three kinds of photoresponsive polymethacrylates containing different bisazo chromophores were prepared with atom transfer radical polymerization and characterized with proton nuclear magnetic resonance, gel permeation chromatography, and ultraviolet–visible spectra. These polymers had similar molecular weights, molecular weight distributions, glass‐transition temperatures, and absorption coefficients. The irradiation of these polymer films with a linearly polarized laser could induce birefringence because of the reorientation of the bisazo chromophores through trans–cis–trans isomerization cycles of double azo bonds, and the corresponding mechanism was also examined. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4237–4247, 2004
Science as a map in technological search
Authors: Fleming Lee , Sorenson Olav
Published: July 2004

A large body of work argues that scientific research increases the rate of technological advance, and with it economic growth. The precise mechanism through which science accelerates the rate of invention, however, remains an open question. Conceptualizing invention as a combinatorial search process, this paper argues that science alters inventors' search processes, by leading them more directly to useful combinations, eliminating fruitless paths of research, and motivating them to continue even in the face of negative feedback. These mechanisms prove most useful when inventors attempt to combine highly coupled components; therefore, the value of scientific research to invention varies systematically across applications. Empirical analyses of patent data support this thesis. Copyright © 2004 John Wiley & Sons, Ltd.
Subsidiaries and knowledge creation: the influence of the MNC and host country on innovation
Authors: Almeida Paul , Phene Anupama
Published: July 2004

This paper studies the influence of external knowledge on innovation in subsidiaries of multinational firms. The focus on subsidiaries is especially interesting since they are simultaneously embedded in two knowledge contexts: (a) the internal multinational corporation (MNC) comprised of the headquarters and other subsidiaries; and (b) an external environment of regional or host country firms. We develop hypotheses to suggest that the extent of influences of these contexts on subsidiary technological innovation depends on the characteristics of the knowledge network (technological richness and diversity) and the knowledge linkages of the subsidiary with other entities. The study uses patent citation data pertaining to innovations by foreign subsidiaries of U.S. semiconductor firms to test these hypotheses. The paper finds that (a) the technological richness of the MNC, (b) the subsidiary's knowledge linkages to host country firms, and (c) the technological diversity within the host country have a positive impact on innovation. Copyright © 2004 John Wiley & Sons, Ltd.
Structure in the classical knot concordance group
Authors: Cochran Tim D. , Orr Kent E. , Teichner Peter
Published: July 2004

We provide new information about the structure of the abelian group of topological concordance classes of knots in

S^3

. One consequence is that there is a subgroup of infinite rank consisting entirely of knots with vanishing Casson–Gordon invariants but whose non-triviality is detected by von Neumann signatures.
Laminations minimales résiduellement à 2 bouts
Authors: Blanc Emmanuel
Published: July 2004

On décrit toutes les feuilles des laminations minimales dont un ensemble résiduel de feuilles ont 2 bouts. We give a complete description of all the leaves of a minimal foliated space with a residual set of 2-ended leaves.
Structure of foliations of codimension greater than one
Authors: Marzougui Habib , Salhi Ezzeddine
Published: July 2004

We study the structure of a foliation of high codimension which admits a transverse foliation. We introduce four families of open saturated sets. These open sets have a simple characterization and allow us to establish a structure theorem as in codimension 1.
Analogies between group actions on 3-manifolds and number fields
Authors: Sikora Adam S.
Published: July 2004

Let a cyclic group

G

act either on a number field

\mathbb L

or on a

3

-manifold

M

. Let

s_{\mathbb L}

be the number of ramified primes in the extension

\mathbb L^G\subset \mathbb L

and

s_M

be the number of components of the branching set of the branched covering

M\to M/G

. In this paper, we prove several formulas relating

s_{\mathbb L}

and

s_M

to the induced

G

-action on

Cl(\mathbb L)

and

H_1(M),

respectively. We observe that the formulas for

3

-manifolds and number fields are almost identical, and therefore, they provide new evidence for the correspondence between

3

-manifolds and number fields postulated in arithmetic topology.
A new critical pair theorem applied to sum-free sets in Abelian groups
Authors: Hamidoune Yahya ould , Plagne Alain
Published: July 2004

We shall prove a new generalization of Vosper critical pair theorem to finite Abelian groups. We next apply this new tool to the theory of

(k,l)

-free sets in finite Abelian groups. In particular, in most cases, we describe the structure of maximal

(k,l)

-free sets and determine the maximal cardinality of such a set. This result allows us for instance to give precisions on an old result of Yap: we are able to describe completely the maximal sum-free sets with cardinality at least one third of that of the ambient group.
Formes différentielles abéliennes, bornes de Castelnuovo et géométrie des tissus
Authors: Hénaut Alain
Published: July 2004

A

d

-web

{\mathcal W}(d)

is given by

d

complex analytic foliations of codimension

n

in

({\mathbb C}^N,0)

such that the leaves are in general position. We are interested in the geometry of such configurations. A complex

({\mathcal A}^{\bullet},\delta)

of

{\mathbb C}

-vector spaces is defined in which

{\mathcal A}^0

corresponds to functions and

{\mathcal A}^p

to

p

-forms of the web

{\mathcal W}(d)

for

1\leq p\leq n

. If

N=kn

with

k\geq 2

, it is proved that

r_p:=\dim_{\,\mathbb C}{\mathcal A}^p

is a finite analytic invariant of

{\mathcal W}(d)

with an optimal upper bound

\pi_{p}(d,k,n)

for

0\leq p\leq n

. These bounds generalize the Castelnuovos ones for genus of curves in

{\mathbb P}^{k}

with degree

d

. Some characterization of the the space

H^0(V_n,\omega^p_{V_n})

of abelian differentials to an algebraic variety

V_n

in

{\mathbb P}^{n+k-1}

of pure dimension

n

with degree

d

is given. Moreover, using duality and Abels theorem, we investigate how for suitable

V_n

the natural complex

\bigr(H^0(V_n,\omega^{\bullet}_{V_n}),d\,\bigr)

and the abelian relation complex

({\mathcal A}^{\bullet},\delta)

of the linear web associated to

V_n

in

({\mathbb C}^{kn},0)

are related.
Classification of graded Hecke algebras for complex reflection groups
Authors: Ram Arun , Shepler A. V.
Published: July 2004

The graded Hecke algebra for a finite Weyl group is intimately related to the geome- try of the Springer correspondence. A construction of Drinfeld produces an analogue of a graded Hecke algebra for any finite subgroup of GL(V ). This paper classifies all the algebras obtained by applying Drinfeld's construction to complex reflection groups. By giving explicit (though non- trivial) isomorphisms, we show that the graded Hecke algebras for finite real reflection groups constructed by Lusztig are all isomorphic to algebras obtained by Drinfeld's construction. The classification shows that there exist algebras obtained from Drinfeld's construction which are not graded Hecke algebras as defined by Lusztig for real as well as complex reflection groups
Usefulness of Known Computed Tomography and Clinical Criteria for Diagnosing Strangulation in Small‐Bowel Obstruction: Analysis of True and False Interpretation Groups in Computed Tomography
Authors: Kim Jung Hoon , Ha Hyun Kwon , Kim Jeong Kon , Eun Hyo Won , Park Kwang Bo , Kim Bong Soo , Kim Tae Kyoung , Kim Jin Chen , Auh Yong Ho
Published: July 2004

Computed tomography (CT) criteria have proven useful, but not sufficient, for diagnosis of bowel strangulation. The purpose of the present study was to evaluate the useof clinical criteria in the interpretation of CT scans as a means of improving the diagnostic accuracy of CT, especially in patients whose CT scans are equivocal for distinguishing simple obstruction from strangulated obstruction. We analyzed the CT scans of 136 patients with simple (n = 70) or strangulated (n = 66) small‐bowel obstruction. Three radiologists interpreted the CT scans independently for the presence of intestinal strangulation. According to their interpretation, 136 patients were divided into two groups, i.e., a false and a true interpretation group. The diagnostic value of known CT and four clinical criteria (tenderness, tachycardia, fever, and leukocytosis) were compared in the two groups. The diagnostic accuracy of CT criteria for distinguishing simple obstructions from strangulated small‐bowel obstructions ranged between 73% and 80%. Of the 136 patients, 31 belonged to the false group and 105 to the true group. The CT criteria that were highly specific in both groups included severe mesenteric haziness, serrated beak, and poor bowel wall enhancement. Among the clinical criteria, both tachycardia and leukocytosis were highly specific in both groups. The number of positive clinical criteria was helpful in making a diagnosis; none or one clinical criterion indicated a simple obstruction, whereas three or four criteria indicated a strangulated obstruction; when this result was applied retrospectively to the false group, the CT diagnostic accuracy improved in 19 of the 31 patients. The use of clinical criteria when CT findings are equivocal, may overcome the inherent limitations of CT for diagnosing strangulated small‐bowel obstruction.
Hydatid Cysts of the Adrenal Gland: Review of Nine Patients
Authors: Akçay Müfide Nuran , Akçay Güngör , Balik A. Ahmet , Böyük Abdullah
Published: July 2004

Adrenal cysts are very rare lesions, especially with parasitic origin. But with the wider application of ultrasonography (US) and computed tomography (CT) more adrenal cysts are detected incidentally. To gain more insight into this entity, the records of nine patients with hydatid cysts of adrenal gland seen at our department from January 1980 till January 2002 are reviewed. There were four men and five women, and their ages ranged from 15 to 80 years (median: 41 years). All of the patients had unilateral cysts. Seven cysts were located on the right and two on the left side. Five of the cysts were primary and four were secondary. In three patients the cysts were found incidentally. The most common presenting symptom was pain, which was present in six patients. An indirect hemagglutination (IHA) test was positive in six cases. In all patients, US and CT successfully imaged all cysts, but the definitive diagnosis was made by macroscopic and microscopic examination of the cyst’s content. The patients were treated surgically. In all patients adrenal glands with the cystic masses were removed. The median follow‐up period was 16 months (range: 6–64 months). No evidence of recurrence was found in any patient. It should not be forgotten that cystic masses of the upper abdomen might also originate from the adrenal gland. The etiology and nature of the cyst should be well researched, and appropriate treatment should be given as soon as possible. Surgical excision of the gland, including the cyst is the treatment of choice.