bluuebunny/crossref_metadata_2025 huggingface dataset:
Porosity of silicon carbide ceramics
Authors: Slutsker A.I. , Betekhtin V.I. , Sinani A.B. , Kadomtsev A.G. , Ordanyan S.S.
Published: August 2005

A set of ceramic samples based on silicon carbide with substantially varying integral porosity (from 1 to 10 %) was studied. The pore size distribution was examined by optical microscopy (for pores ranging from 10 mm to hundreds of microns in size), scanning electron microscopy (0.5 - 10 mm), and small-angle X-ray scattering (0.04 - 0.20 mm). The obtained pore size distribution function was used to estimate the integral porosity of ceramics, which was compared with the estimates of porosity obtained by the dilatometric technique. Relative contributions of large, small, and fine pores into the integral porosity of ceramics were found. The average pore sizes and average distances between them were estimated for each range of pore sizes.
Anneal hardening effect in sintered copper alloys
Authors: Nestorovic Svetlana , Milicevic Boran , Markovic Desimir
Published: August 2005

Samples of copper and copper alloys CuNi and CuNiAl were prepared by a powder metallurgical method and were then subjected to cold rolling with different degrees of deformation. Copper and copper alloys in the cold-rolled state were isochronally annealed up to the recrystallization temperature during which hardness and electrical conductivity were measured. This investigation shows that the anneal hardening effect occurs in a temperature range of 450 - 650 K, followed with an increase in hardness of alloys.
Mechanoactivation of chromium silicide formation in the SiC-Cr-Si system
Authors: Vlasova M. , Kakazey M. , Gonzales-Rodriguez J.G. , Dominguez G. , Ristic Momcilo , Scherbina O. , Tomila T. , Isaeva L. , Timofeeva I.I. , Bukov A.
Published: August 2005

The processes of simultaneous grinding of the components of a SiC-Cr-Si mixture and further temperature treatment in the temperature range 1073-1793 K were studied by X-ray phase analysis, IR spectroscopy, electron microscopy, and X-ray microanalysis. It was established that, during grinding of the mixture, chromium silicides form. A temperature treatment completes the process. Silicide formation proceeds within the framework of the diffusion of silicon into chromium. In the presence of SiO2 in the mixture, silicide formation occurs also as a result of the reduction of silica by silicon and silicon carbide. The sintering of synthesized composite SiC-chromium silicides powders at a high temperature under a high pressure (T = 2073 K, P = 5 GPa) is accompanied by the destruction of cc-SiC particles, the cc/3 transition in silicon carbide and deformation distortions of the lattices of chromium silicides.
Sintering of low-melting glass powders and glass-abrasive composites
Authors: Shilo A.E. , Bondarev E.K. , Kukharenko S.A.
Published: August 2005

Sintering of glass powders in Na2O-B2O3-SiO2 and PbO-ZnO-B2O3-SiO2 systems as well as of their mixtures has been studied. The process of sintering is shown to change because of crystallization of the glass of the PbO-ZnO-B2O3-SiO2 system. Addition of diamond or cubic boron nitride to glass powders affects shrinkage in sintering composites. Sintering of powders of lead-containing glass proceeds by the mechanism of viscous flow.
Influence of mechanochemical activation of a charge on properties of mullite-tialite materials
Authors: Antsiferov V.N. , Porozova S.E. , Matygullina E.V.
Published: August 2005

The influence of mechanochemical activation (MCA) of a kaolin-containing charge on the strength of mullite-tialite materials (obtained using methods of semidry molding and polymeric matrix duplication) was studied. It is shown that spectral and X-ray indexes of crystallinity of kaolin activated under similar conditions could be used as criteria of MCA efficiency. Parameters of mullite-tialite charge (containing kaolin, alumina and anatase) activation were optimized. .
Application of the plasticity characteristic determined by the indentation technique for evaluation of mechanical properties of coatings: II. guidelines to coating development and processing control
Authors: Byakova A.V. , Milman YU.V. , Vlasov A.A.
Published: August 2005

The equilibrium between solid and 1iquid phases in sintered composite materials has been studied. It is shown that closed surfaces, which bound dispersed phases, influence the mechanical equilibrium between these phases. An expression is derived for a dihedral angle in composite materials, which includes values of surface tensions at the phase interfaces as well as parameters of a composite equilibrium structure (phase composition, particle contiguity and coefficients of a particle geometry). .
Structure study of donor doped barium titan ate prepared from citrate solutions
Authors: Stojanovic B.D. , Mastelaro V.R. , Paiva Santos , Varela J.A.
Published: August 2005

Barium titanates doped with Nb5+, and Y3+, were prepared. The starting powders were synthesized from citrate solutions by the Pechini process and partial Pechini process in two steps. Sintering was performed in the range from 13100 up to 13800C for 2 hours in air atmosphere. The structural study concerning the incorporation of Nb and Y ions in the barium titan ate crystal lattice was performed by XRD, XANES and EXAFS techniques. The dielectric properties were analyzed and the relationship between properties and structure of doped barium titan ate was established.
Characterization of dispersion strengthened copper with 3wt%Al2O3 by mechanical alloying
Authors: Rajkovic Viseslava , Eric Olivera , Bozic Dusan , Mitkov M. , Romhanji Endre
Published: August 2005

The copper matrix has been dispersion strengthened with 3wt.%Al2O3 by mechanical alloying. Commercial alumina powder with an average particle size of 0.75mm was used for alloying. The mechanical alloying process was performed in a planetary ball mill up to 20h in air. After milling all powders were treated in H2 at 4000C for 1h, and finally hot pressing was used for compaction (800oC, 3h, Ar). Structure observations revealed a lamellar structure (Al2O3 particles largely restricted to interlamellar planes between adjacent copper lamellae) accompanied also by structure refinement. These structural changes were mostly completed in the early stage of milling, and retained after compaction. Micro hardness was found to progressively increase with milling time. So, after 5h of milling the micro hardness of the Cu+3twt%Al2O3 compact was 1540MPa, i.e. 2.5 times greater than for the as-received electrolytic copper powder (638MPa) compacted under identical conditions, while after 20h of milling it was 2370 MPa. However after exposing the tested compact at 800oC up to 5h, the achieved hardening effect vanished.
Muscle‐bone interactions in dystrophin‐deficient and myostatin‐deficient mice
Authors: Montgomery Eric , Pennington Catherine , Isales Carlos M. , Hamrick Mark W.
Published: August 2005

We have investigated muscle‐bone interactions using two mouse mutants that are known to differ from normal mice in skeletal muscle growth and development: mice lacking myostatin (GDF8) and mice lacking dystrophin (mdx). Myostatin‐deficient mice show increased muscle size and strength compared to normal mice, whereas the mdx mouse is a well‐established animal model for Duchenne muscular dystrophy. The mdx mice have significantly larger hindlimb muscles than controls, and histological sections of the quadriceps muscles show dystrophic changes with extensive fibrosis. Femoral bone mineral density (BMD) and fracture strength (Fu) are significantly greater in mdx mice than controls, and these variables are more strongly correlated with quadriceps muscle mass than with body mass. In contrast, mdx mice do not shower high bone mineral density in the spine relative to controls, whereas myostatin‐deficient mice have significantly increased BMD in the lumbar spine compared to normal mice. Both mdx mice and myostatin‐deficient mice have expanded femoral trochanters for attachment of large hindlimb muscles, and both mutant strains show increased cross‐sectional area moments of inertia mediolaterally (Iyy) but not anteroposteriorly (Ixx) compared to normal mice. These data suggest that lean (muscle) mass is a significant determinant of bone mineral density and strength in the limb skeleton, even when accompanied by a dystrophic phenotype. Likewise, increased muscle mass produces a marked increase in the external dimensions of muscle attachment sites, even when increased muscle size is accompanied by extensive fibrosis and muscle weakness. © 2005 Wiley‐Liss, Inc.
Simple electrospray mass spectrometry detection of acylhomoserine lactones
Authors: Makemson John , Eberhard Anatol , Mathee Kalai
Published: August 2005

Simple (non‐tandem) electrospray mass spectrometry (ESMS) can detect acyl homoserine lactones (AHL) in bacteriological media in picomole amounts. The chemical reactivity of AHLs and their extraction behaviour into ethyl acetate, coupled with detection in the ESMS, has shown that these lactones can be detected as the protonated pseudomolecular ions themselves as well as solvent and ammonium adducts, and as dimers. ESMS detects and identifies these molecules, utilizing simple chemical properties of AHLs. Copyright © 2005 John Wiley & Sons, Ltd.
Multivariate analysis of factors associated with renal dysfunction in patients with obstructive jaundice
Authors: Padillo F J , Cruz A , Briceño J , Martin-Malo A , Pera-Madrazo C , Sitges-Serra A
Published: August 2005

Background

The aim was to evaluate the factors determining preoperative renal dysfunction in patients with obstructive jaundice.

Methods

In a prospective cross-sectional observational study, 63 patients, 27 with benign and 36 with malignant obstructive jaundice, were investigated at admission and compared with 25 healthy control subjects. Variables analysed included extracellular body water (ECW) compartment, plasma levels of aldosterone, renin, atrial natriuretic peptide, vasopressin, nitric oxide, endothelin (ET) 1 and prostaglandin E2 (PGE2), urinary nitric oxide and PGE2, serum albumin and renal function.

Results

The metabolic profile of obstructive jaundice was characterized by a depletion of the ECW (P = 0·004), and increased plasma levels of atrial natriuretic peptide (P < 0·001), ET-1 (P = 0·044), vasopressin (P = 0·017), aldosterone (P = 0·005) and renin (P = 0·001). Increased plasma (P < 0·001) and urinary (P = 0·001) PGE2 levels were also found. Fifty-four per cent of patients had a creatinine clearance of less than 70 ml/min. In multivariate analysis, serum bilirubin, renin, ET-1, PGE2, decreased urinary sodium excretion and age were identified as predictors of renal dysfunction.

Conclusions

Renal dysfunction in patients with obstructive jaundice was associated with the degree of biliary obstruction, age of the patient and reduced urinary sodium excretion. These alterations were closely related to derangements in sodium- and water-regulating hormones.
Seeing sustainability in business operations: US and British food retailer experiments with accountability
Authors: Iles Alastair
Published: August 2005

This article compares how food retail industries in Britain and the United States are facing sustainability challenges. The British and US industries are in different stages of maturity in identifying and responding to sustainability. Some UK retailers have begun developing broad‐based accountability systems that may aid them to see sustainability in their business operations. By examining what retailers are doing, how accountability systems can inform retailers and the business case for accountability, this article argues that retailers can gain significant business advantages with strategies to improve accountability. Compared with their American counterparts, British retailers may be better placed to deal with sustainability issues in future. Copyright © 2005 John Wiley & Sons, Ltd and ERP Environment.
Bifurcation Analysis of the Fluidized Bed Polyethylene Reactor with Internal Cooler
Authors: Ghasem N. M.
Published: August 2005

A mathematical model has been developed to simulate a gas‐phase ethylene polymerization reactor with internal cooler. The model was analyzed to determine the effects of reactor operating conditions on dynamics and stability. The reactor model employed assumed that both the gas and polymer phase in the reactor are well mixed. Comparing the present model to one with external heat exchanger confirms that, in either form, gas‐phase polyethylene reactors are prone to show unstable steady states, limit cycles and excursions toward unacceptably high temperature steady states. It was also observed that, with internal cooler, minor design changes in the cooler area available for heat transfer and in the inlet temperature of the coolant have a significant effect on the low stable steady state range of catalyst feed rates. With internal cooler, the suitable operating range increased with the increase in the area available for heat transfer. This effect is insignificant in the case of a reactor with external heat exchanger. Manipulating the reactor coolant inlet temperature and/or gas velocity can increase the stability range in the reactor with internal cooler as against one with external heat exchanger.
Enhancement of Propylene Production in a Downer FCC Operation using a ZSM‐5 Additive
Authors: Abul‐Hamayel M. A. , Aitani A. M. , Saeed M. R.
Published: August 2005

The effects of high severity operation and ZSM‐5 addition on the FCC product yield distribution have been studied in a down‐flow reactor unit. VGO cracking at high reaction temperatures of 500–650 °C increases the yield of light olefins (propylene and butenes) with a corresponding loss in gasoline yield and increase in dry gas formation. Similar behavior is observed with the addition of 0–20 wt % ZSM‐5 additive, however, with no increase in dry gas. The combination of the two effects (high severity and ZSM‐5 addition) makes the FCC unit an excellent source of light olefins for downstream petrochemical and alkylation units. The novel process configuration increased the light olefin yield without significant loss in gasoline by suppressing thermal cracking reactions and dry gas formation.
Distinction between Electrostatic and Electrokinetic Effects on the Permeability of Colloidal Packed Beds
Authors: Schäfer B. , Nirschl H.
Published: August 2005

Electrostatic and electroviscous effects can significantly decrease the permeability of packed beds which consist of colloidal particles. This results in poor filterability of colloidal suspensions. Electrostatic effects refer to the dependency of the structure of the packed bed on the particles' tendency to agglomerate or disagglomerate. This tendency is influenced by the particle charge, and thus the pH and the ionic strength of the suspension. Electroviscous effects relate to the increased flow resistance of the pores due to a streaming potential being established when the electrochemical double layer of the particles is sheared off. It is difficult to distinguish electrostatic and electroviscous effects because they are interrelated. The comparison of permeability measurements of both TiO2 and Al2O3 with a classical permeability model demonstrates the influence of the two different effects on permeability.
A New Synthesis of (PhPSe2)2 (Woollins Reagent) and Its Use in the Synthesis of Novel P–Se Heterocycles
Authors: Gray Ian P. , Bhattacharyya Pravat , Slawin Alexandra M. Z. , Woollins J. Derek
Published: August 2005

A new and improved method for the preparation of (PhPSe2)2 (Woollins reagent (WR), 1) is reported. Reaction of dichlorophenylphosphine with Na2Se, (prepared from the reaction of elemental selenium and sodium in liquid ammonia) gives WR with excellent purity, high yield and on a larger scale than was previously possible. Four novel phosphorus–selenium heterocycles, including a spirocyclic heterocycle exhibiting a four‐membered P2SeC ring, were obtained from the reaction of WR with two reactive substrates (diphenylcyclopropenone and methyl phenylpropiolate). Useful selenocarbonyl and thiocarbonyl compounds were obtained from the reaction of both WR and Lawesson's reagent with diphenylcyclopropenone. All new compounds were characterised spectroscopically and three demonstrative X‐ray structures are reported.
Metal Ion Coordination to Azole Nucleosides
Authors: Müller Jens , Böhme Dominik , Lax Patrick , Morell Cerdà Marta , Roitzsch Michael
Published: August 2005

To evaluate the possibility of introducing azole nucleosides as building blocks for metal‐mediated base pairs in artificial oligonucleotides, imidazole nucleoside, 1,2,4‐triazole nucleoside and tetrazole nucleoside have been synthesized and characterized. The X‐ray crystal structures of p‐toluoyl‐protected 1,2,4‐triazole and tetrazole nucleosides are reported. Contrary to the situation primarily found for deoxyribonucleosides, the sugar moieties adopt C3′‐endo conformations. The acidity of the β nucleosides increases with increasing number of nitrogen ring atoms, giving pKa values of 6.01±0.05, 1.32±0.05 and <−3, respectively. This decrease in basicity results in a decreasing ability to form 2:1 complexes with linearly coordinating metal ions such as Ag+ and Hg2+. In all cases, the Ag+ complexes are of higher stability than the corresponding Hg2+ complexes. Whereas imidazole nucleoside forms highly stable 2:1 complexes with both metal ions (estimated log β2 values of >10), only Ag+ is able to reach this coordination pattern in the case of triazole nucleoside (log β2 = 4.3±0.1). Tetrazole nucleoside does not form 2:1 complexes at all under the experimental conditions used. These data suggest that imidazole nucleoside, and to a lesser extent 1,2,4‐triazole nucleoside, are likely candidates for successful incorporation as ligands in oligonucleotides based on metal‐mediated base pairs. DFT calculations further corroborate this idea, providing model complexes for such base pairs with glycosidic bond distances (10.8–11.0 Å) resembling those in idealized B‐DNA (10.85 Å).
Thiosilicates of the Rare‐Earth Elements. Part 3. KLa[SiS4] and RbLa[SiS4] — A Structural Comparison.
Authors: Hartenbach Ingo , Schleid Thomas
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Preparation and Crystal Structure of MnBiSe2I.
Authors: Pfitzner Arno , Zabel Manfred , Rau Franz
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Synthesis and Photoluminescence of Pb5(VO4)3OH Nanocrystals.
Authors: Zhang Haiping , Lu Mengkai , Xiu Zhiliang , Zhou Guangjun , Wang Shufen
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Isotopic Magnetic Exchange Between Anisotropic Yb(III) Ions. Study of Cs3Yb2Cl9 and Cs3Yb2Br9 Crystals.
Authors: Palii Andrei V. , Tsukerblat Boris S. , Clemente‐Juan Juan M. , Coronado Eugenio
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Pressure‐Induced Amorphization and Phase Transformations in β‐LiAlSiO4.
Authors: Zhang Jianzhong , Zhao Yusheng , Xu Hongwu , Zelinskas Matthew V. , Wang Liping , Wang Yanbin , Uchida Takeyuki
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
{Sn[Zn4Sn4S17]}6‐: A Robust Open Framework Based on Metal‐Linked Penta‐Supertetrahedral [Zn4Sn4S17]10‐ Clusters with Ion‐Exchange Properties.
Authors: Manos Manolis J. , Iyer Ratnasabapathy G. , Quarez Eric , Liao J. H. , Kanatzidis Mercouri G.
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Hydrothermal Synthesis and Structural Characterization of a Novel NLO Compound, La(MoO2)(OH)(IO3)4.
Authors: Chen Xuean , Chang Xinan , Zang Hegui , Wang Qian , Xiao Weiqiang
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Crystal Structure of 4‐Hydroxy‐2‐methyl‐5H‐naphtho[1′,2′:5,6]pyrano [4,3‐b]Pyridin‐5‐one: A New Heterohelicene.
Authors: Kettmann Viktor , Svetlik Jan
Published: August 2005

For Abstract see ChemInform Abstract in Full Text.
Wide excision without radiation for desmoplastic melanoma
Authors: Arora Alisha , Lowe Lori , Su Lyndon , Rees Riley , Bradford Carol , Cimmino Vincent C. , Chang Alfred E. , Johnson Timothy M. , Sabel Michael S.
Published: August 2005

BACKGROUND

Adjuvant radiation has been proposed for the treatment of patients with desmoplastic melanoma, who reportedly have local recurrence rates as high as 40–60%. The authors investigated local recurrence rates at a tertiary referral center to determine the success of wide excision alone for patients with desmoplastic melanoma.

METHODS

A review of a prospectively maintained melanoma clinical data base identified 65 patients between March 1997 and March 2004 with pure cutaneous desmoplastic melanoma. Complete surgical, histopathologic, and staging information was collected along with data on outcome, including local, regional, and distant recurrence and survival.

RESULTS

Similar to previous reports, patients with desmoplastic melanoma had a male‐to‐female ratio of 2 to 1, a mean age of 65.0 years (range, 31–92 yrs), and the majority of their tumors (55%) were located on the head and neck. The mean Breslow depth at diagnosis was 4.21 mm, with 38% of tumors thicker than 4.0 mm. All patients in this series underwent wide excision without radiation therapy. Surgical margins ≤ 2 cm were obtained for all trunk and extremity lesions and for 63% of head and neck lesions that measured > 1 mm in depth (63%). Margins of 1–2 cm were obtained for the remaining patients. Among 49 patients who had a minimum of 2 years of follow‐up (mean, 3.7 yrs), the local recurrence rate was 4% (2 of 49 patients). Seventy‐eight percent of the patients studied remained alive with no evidence of disease.

CONCLUSIONS

Local recurrence rates in the current series were considerably lower than the historically reported rates. This finding suggests that, for patients with desmoplastic melanoma, wide local excision with careful attention to appropriate margins produces excellent local control rates without the need for adjuvant radiation. Cancer 2005. © 2005 American Cancer Society.
On the Position of the Highest Occupied Molecular Orbital in Aqueous Solutions of Simple Ions
Authors: Hunt Patricia , Sprik Michiel
Published: August 2005

The energies of the highest occupied molecular orbital (HOMO) of four simple microsolvated aqua ion clusters (Na+, Ag+, Cl−, CN−) are computed for varying numbers of water molecules. Extrapolating to infinite hydration numbers we find that these energies approach a value of −6 eV. This limiting one‐electron energy is within a margin of ±1 eV independent of the character of the ion and is 4 eV lower compared to the estimate obtained for the HOMO energy of the ions in aqueous solution under periodic boundary conditions. We argue that this discrepancy must the attributed to a shift in the reference of the one‐electron potential of the periodic solvent model.
Cognitive processing in Chinese literate and illiterate subjects: An fMRI study
Authors: Li Geng , Cheung Raymond T.F. , Gao Jia Hong , Lee Tatia M.C. , Tan Li Hai , Fox Peter T. , Jack Clifford R. , Yang Edward S.
Published: August 2005

Functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) were used to map brain activation during language tasks. While previous studies have compared performance between alphabetic literate and illiterate subjects, there have been no such data in Chinese‐speaking individuals. In this study, we used fMRI to examine the effects of education on neural activation associated with silent word recognition and silent picture‐naming tasks in 24 healthy right‐handed Chinese subjects (12 illiterates and 12 literates). There were 30 single Chinese characters in the silent word recognition task and 30 meaningful road‐signs in the silent picture‐naming task. When we compared literate and illiterate subjects, we observed education‐related differences in activation patterns in the left inferior/middle frontal gyrus and both sides of the superior temporal gyrus for the silent word recognition task and in the bilateral inferior/middle frontal gyrus and left limbic cingulated gyrus for the silent picture‐naming task. These results indicate that the patterns of neural activation associated with language tasks are strongly influenced by education. Education appears to have enhanced cognitive processing efficiency in language tasks. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Modelling combined open channel flow by artificial neural networks
Authors: Yang Han‐Chung , Chang Fi‐John
Published: August 2005

Combined open channel flow is encountered in many hydraulic engineering structures and processes, such as irrigation ditches and wastewater treatment facilities. Extensive experimental studies have conducted to investigate combined flow characteristics. Nevertheless, there is no simple relationship that can fully describe the velocity profiles in a turbulent flow. The artificial neural network (ANN) has great computational capability for solving various complex problems, such as function approximation. The main objective of this study is to evaluate the applicability of the ANN for simulating velocity profiles, velocity contours and estimating the discharges accordingly. The velocity profiles measured by an acoustic doppler velocimeter in the open channel of the Chihtan purification plant, Taipei, with different discharges at fixed measuring section and different depths are presented. The total number of data sets is 640 and the data sets are split into two subsets, i.e. training and validation sets. The backpropagation algorithm is used to construct the neural network. The results demonstrate that the velocity profiles can be modelled by the ANN, and the ANN constructed can nicely fit the velocity profiles and can precisely predict the discharges for the conditions investigated. Copyright © 2005 John Wiley & Sons, Ltd.
Semi‐distributed modelling of the monthly water balance in an alpine catchment
Authors: Eder Gerald , Fuchs Martin , Nachtnebel Hans‐Peter , Loibl Wolfgang
Published: August 2005

The need for estimates of distributed water balance in alpine catchments is addressed. Such estimates are an essential prerequisite for the efficient planning and management of water resource use. Specifically, the maximum appropriate spatial resolution that can be obtained in water balance estimates is assessed, given limited information of physiographic parameters and meteorological variables, in a complex topographical environment. This is done using a combination of existing modelling methodologies. The use of spatial disaggregation into subregions of similar climatic and topographic properties has been used as an optimal method for considering all stages of water balance estimation, from input data generation to model parameterization and water balance simulation. Various techniques for the spatial interpolation of precipitation and temperature point observations are evaluated in terms of their applicability to mountainous terrain, and external drift kriging is found to be the most suitable. A water balance model is introduced for an alpine catchment, capable of integrating dominant hydrological processes, for the computation of monthly and regional distributed water balances. The conceptual model is characterized by minimal model complexity, with most of the parameters estimated a priori from catchment physiography, in order to avoid an automatic model calibration. The hydrological water balance model is applied to the transboundary Gail river catchment, located between Austria and Italy, south of the main alpine divide. Copyright © 2005 John Wiley & Sons, Ltd.
Antimicrobial effects and human gingival biocompatibility of hydroxyapatite sol–gel coatings
Authors: Chung Ren‐Jei , Hsieh Ming‐Fa , Huang Chine‐Wen , Perng Li‐Hsiang , Wen Hsiao‐Wei , Chin Tsung‐Shune
Published: August 2005

The sol–gel method was employed to synthesize hydroxyapatite (HAp) coatings modified with Ag or Zn ions onto Ti‐6Al‐4V substrate. A bacterial strain Streptococcus mutans (S. mutans) and a human gingival fibroblast (HGF‐1) cell line were used to investigate the antimicrobial effect and biocompatibility, respectively. HAp coatings containing 100 ppm Ag+ ions suppressed the growth of S. mutans. An apparent inhibition zone around the HAp coating was further observed at Ag+ concentration up to 10,000 ppm. However, for coatings containing Zn2+ ions, a clear inhibition zone was observed at Zn2+ concentration of 10,000 ppm. Nevertheless, the results of HGF‐1 cultivation demonstrated that the Zn2+‐modified HAp coatings exhibited better attachment and spread of HGF‐1 than did the Ag+‐modified coatings. Zn2+ modified HAp coatings also increased the plating efficiency of HGF‐1 cells. The cytotoxicity associated with the addition of Ag and the cell‐conductive capacity associated with the addition of Zn are proportional to the added concentration, from 100 to 10,000 ppm. The dosages of both Ag+ and Zn2+ ions that should be added to HAp coatings were considered to prevent infection and improve biocompatibility. The results of this study ensure that HAp coatings modified with a moderate amount of Ag/Zn efficiently resist microorganisms and improve biocompatibility. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
The reciprocal nature of trust: a longitudinal study of interacting teams
Authors: Serva Mark A. , Fuller Mark A. , Mayer Roger C.
Published: August 2005

This research develops and investigates the concept of reciprocal trust between interacting teams. Reciprocal trust is defined as the trust that results when a party observes the actions of another and reconsiders one's trust‐related attitudes and subsequent behaviors based on those observations. Twenty‐four teams of systems analysis and design students were involved in a 6‐week controlled field study focused on the development of an information systems project. Each team was responsible for both developing a system (development role) and for supervising the development of a system by another team (management role). Risk‐taking actions exhibited by one team in an interacting pair were found to predict the other team's trustworthiness perceptions and subsequent trust. The level of trust formed in turn predicted the team's subsequent risk‐taking behaviors with respect to the other team. This pattern of reciprocal trust repeated itself as the teams continued to interact over the duration of the project, thus supporting our model of reciprocal trust. Findings also indicate that trust and trust formation can occur at the team level. Copyright © 2005 John Wiley & Sons, Ltd.
Femtosecond photon echo in dye-doped polymer film at room temperature
Authors: Lobkov V S , Salikhov K M , Samartsev V V , Safiullin G M , Zuikov V A
Published: August 2005

The first observation is reported of the primary and
stimulated femtosecond photon echoes at liquid nitrogen and room
temperatures in a dye-doped polymer film at a wavelength of
780 nm. Echo signals were generated by pulses with the duration of
65 fs. The primary echo signal decay at liquid nitrogen and room
temperatures can not be described by a simple exponential
function. The decay of primary echo signal at room temperature
demonstrates complex behavior caused by the presence of the
phonon-side band in the optical band of impurity centers. There
were also detected signals of the self-diffraction of exciting
pulses on a nonequilibrium population difference grating, induced
in resonant medium by these pulses.
Front Cover: Macromol. Chem. Phys. 15/2005
Authors: Börger Volker , Kuliskovska Olga , G.‐Hubmann Kati , Stumpe Joachim , Huber Marco , Menzel Henning
Published: August 2005

Front Cover: Azobenzene undergoes E‐Z‐isomerization upon irradiation. Polarized interfering light beams causing repeated isomerization cycles and a photoreorientation of the azobenzene groups result in a massive mass transport over μm distances. Employing polymers with different concentrations of photoactive groups it was investigated how many molecular motors are necessary to get polymer moving. Further details can be found in the Full Paper by V. Börger, O. Kuliskovska, K. G.‐Hubmann, J. Stumpe, M. Huber, and Henning Menzel* on page 1488.
Effect of Impurities on the Syndiospecific Coordination Polymerization of Styrene
Authors: Schellenberg Jürgen
Published: August 2005

Summary: The effect of impurities on the coordination polymerization has generally been classified and discussed in different ways and has been investigated in detail in the syndiospecific homo‐ and copolymerization of styrene. With regard to impurities of styrene, phenylacetylene as an unpolar impurity containing separate multiple bonds, 1‐phenyl‐1,2‐ethanediol and ω‐hydroxyacetophenone as examples of polar impurities, and ethylbenzene as an other unpolar impurity have been investigated regarding the effect on the polymerization rate and the influence on the molecular properties of the syndiotactic polystyrenes. In the syndiospecific copolymerization with p‐methylstyrene, indene shows a different behavior regarding the decrease of the polymerization conversion depending on the comonomer concentrations present in the monomer mixture. Additionally, the effect of impurities of the catalyst system on the syndiospecific styrene polymerization has been demonstrated, particularly of octahydrofluorene as a component of the transition metal compound and of trimethylaluminium as a component of the cocatalyst methylaluminoxane. All results have been discussed with respect to the mechanisms of the effects on polymerization behavior and on polymer properties.

Dependence of the relative polymerization conversion on the amount of indene added to the monomer mixture in styrene (ST)/p‐methylstyrene (PMS) copolymerization (catalyst n‐ratio: 0.5; molar ratio MAO:Ti = 110:1; polymerization temperature: 60 °C; polymerization time: 45 min).

magnified image

Dependence of the relative polymerization conversion on the amount of indene added to the monomer mixture in styrene (ST)/p‐methylstyrene (PMS) copolymerization (catalyst n‐ratio: 0.5; molar ratio MAO:Ti = 110:1; polymerization temperature: 60 °C; polymerization time: 45 min).
Structure and Properties of Nanocomposites Based on Poly(butylene succinate‐co‐adipate) and Organically Modified Montmorillonite
Authors: Ray Suprakas Sinha , Bousmina Mosto , Okamoto Kazuaki
Published: August 2005

Summary: Poly(butylene succinate‐co‐adipate) (PBSA) and organically modified montmorillonite (OMMT) nanocomposites of three different compositions were prepared by melt‐extrusion in a batch mixer. The structure of the nanocomposites was studied using X‐ray diffraction (XRD) and transmission electron microscopy (TEM) that revealed a coexistence of exfoliated and intercalated silicate layers dispersed in the PBSA matrix, regardless of the silicate loading. The degree of crystallinity of PBSA decreases with the addition of OMMT platelets. Dynamic mechanical analysis revealed remarkable increase in flexural storage modulus when compared with that of neat PBSA. Tensile property measurements exhibit substantial increase in stiffness with simultaneous increase in elongation at break of nanocomposites as compared to that of neat PBSA. The effect of clay loading on the melt‐state linear viscoelastic behavior of mixed intercalated/exfoliated nanocomposites was also investigated.

Elongation at break of compression molded annealed samples of neat PBSA and various PBSACNs.

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Elongation at break of compression molded annealed samples of neat PBSA and various PBSACNs.
Synthesis and Characterization of Novel Aliphatic Poly(carbonate‐ester)s with Functional Pendent Groups
Authors: Zhou Yu , Zhuo Ren‐Xi , Liu Zhi‐Lan
Published: August 2005

Summary: A novel cyclic carbonate monomer 5‐methyl‐5‐(succinimide‐N‐oxycarbonyl)‐1,3‐dioxan‐2‐one (MSTC) was prepared. The copolymers of MSTC with caprolactone (CL) were further synthesized by ring‐opening copolymerization. The copolymers with amido‐amine pendent groups were obtained by aminolysis of poly(MSTC‐co‐CL) with ethylenediamine. These copolymers were characterized by IR, 1H NMR, 13C NMR spectroscopies and GPC. The hydrophilicity and degradability of the copolymers with amido‐amine pendent groups were greatly improved in comparison with the PCL homopolymer.

Hydrophilicity of PCL (1), poly(MATC‐co‐CL) (16.5:83.5) (2), and poly(MATC‐co‐CL) (29.5:70.5) (3).

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Hydrophilicity of PCL (1), poly(MATC‐co‐CL) (16.5:83.5) (2), and poly(MATC‐co‐CL) (29.5:70.5) (3).
Chorea associated with thyroxine replacement therapy
Authors: Isaacs Jeremy D. , Rakshi James , Baker Richard , Brooks David J. , Warrens Anthony N.
Published: August 2005

Chorea is an uncommonly reported manifestation of hyperthyroidism. We report the first description of generalized chorea due to iatrogenic thyrotoxicosis and propose that the movement disorder is due to a direct effect of thyroxine on the basal ganglia rather than being an autoimmune phenomenon. © 2005 Movement Disorder Society
A simultaneous solution procedure for strong interactions of generalized Newtonian fluids and viscoelastic solids at large strains
Authors: Hübner B. , Dinkler D.
Published: August 2005

The paper presents a methodology for numerical analyses of coupled systems exhibiting strong interactions of viscoelastic solids and generalized Newtonian fluids. In the monolithic approach, velocity variables are used for both solid and fluid, and the entire set of model equations is discretized with stabilized space–time finite elements. A viscoelastic material model for finite deformations, which is based on the concept of internal variables, describes the stress‐deformation behaviour of the solid. In the generalized Newtonian approach for the fluid, the viscosity depends on the shear strain rate, leading to common non‐Newtonian fluid models like the power‐law. The consideration of non‐linear constitutive equations for solid and fluid documents the capability of the monolithic space–time finite element formulation to deal with complex material models. The methodology is applied to fluid‐conveying cantilevered pipes in order to determine the influence of material non‐linearities on stability characteristics of coupled systems. Copyright © 2005 John Wiley & Sons, Ltd.
Hemoglobin Hammersmith [β 42(CD1) Phe → Ser] causing severe hemolytic anemia in a Japanese girl
Authors: Akiyama Masaharu , Murayama Shizuko , Yokoi Kentaro , Yanagisawa Takaki , Hattori Yukio , Yamashiro Yasuhiro , Eto Yoshikatsu , Fujisawa Kohji
Published: August 2005

Hemoglobin Hammersmith, a rare, unstable hemoglobin variant, was diagnosed in a 9‐year‐old Japanese girl. She presented with the typical manifestations of this disorder, including neonatal hyperbilirubinemia, followed by progressive hepatosplenomegaly, jaundice, and bilirubinuria. Because of severe hemolytic anemia, she received transfusions of red blood cells every 3 to 4 weeks. However, she underwent splenectomy at the age of 4 years and has continued to be in partial remission without requiring further transfusions. DNA sequence analysis of the polymerase chain reaction‐amplified β‐globin gene revealed a point mutation (T → C) in the second nucleotide of the 42nd codon of the β‐globin chain (β 42(CD1) Phe → Ser). Pediatric Blood Cancer 2006;47:839–841. © 2005 Wiley‐Liss, Inc.
ABACUS, a direct method for protein NMR structure computation via assembly of fragments
Authors: Grishaev A. , Steren C.A. , Wu B. , Pineda‐Lucena A. , Arrowsmith C. , Llinás M.
Published: August 2005

The ABACUS algorithm obtains the protein NMR structure from unassigned NOESY distance restraints. ABACUS works as an integrated approach that uses the complete set of available NMR experimental information in parallel and yields spin system typing, NOE spin pair identities, sequence specific resonance assignments, and protein structure, all at once. The protocol starts from unassigned molecular fragments (including single amino acid spin systems) derived from triple‐resonance 1H/13C/15N NMR experiments. Identifications of connected spin systems and NOEs precede the full sequence specific resonance assignments. The latter are obtained iteratively via Monte Carlo‐Metropolis and/or probabilistic sequence selections, molecular dynamics structure computation and BACUS filtering (A. Grishaev and M. Llinás, J Biomol NMR 2004;28:1–10). ABACUS starts from scratch, without the requirement of an initial approximate structure, and improves iteratively the NOE identities in a self‐consistent fashion. The procedure was run as a blind test on data recorded on mth1743, a 70‐amino acid genomic protein from M. thermoautotrophicum. It converges to a structure in ca. 15 cycles of computation on a 3‐GHz processor PC. The calculated structures are very similar to the ones obtained via conventional methods (1.22 Å backbone RMSD). The success of ABACUS on mth1743 further validates BACUS as a NOESY identification protocol. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Atomically detailed potentials to recognize native and approximate protein structures
Authors: Qiu Jian , Elber Ron
Published: August 2005

Atomically detailed potentials for recognition of protein folds are presented. The potentials consist of pair interactions between atoms. One or three distance steps are used to describe the range of interactions between a pair. Training is carried out with the mathematical programming approach on the decoy sets of Baker, Levitt, and some of our own design. Recognition is required not only for decoy–native structural pairs but also for pairs of decoy and homologous structures. Performance is tested on the targets of CASP5 using templates from the Protein Data Bank, on two test ab initio decoy sets from Skolnick's laboratory, and on decoy sets from Moult's laboratory. We conclude that the newly derived potentials have significant recognition capacity, comparable to the best models derived from other techniques. The new potentials require a significantly smaller number of parameters. The enhanced recognition capacity extends primarily to the identification of structures generated by ab initio simulation and less to the recognition of approximate shapes created by homology. Proteins 2005. © 2005 Wiley‐Liss, Inc.
Peptides delivered by immunostimulating reconstituted influenza virosomes
Authors: Westerfeld Nicole , Zurbriggen Rinaldo
Published: August 2005

Vaccines have been well accepted and used effectively for more than 100 years. Traditional vaccines are generally composed of whole inactivated or attenuated microorganisms that have lost their disease‐causing properties. These classical prophylactic live vaccines evoke protective immune responses, but have often been associated with an unfavorable safety profile, as observed, for example, for smallpox and polio myelitis vaccines1, 2. First improvements were subunit vaccines that do not focus on attenuation of whole organisms but concentrate on particular proteins. These vaccines are able to generate protective immune responses (e.g. diphtheria, tetanus, pertussis)3. However, next generation vaccines should focus on specific antigens (e.g. proteins, peptides), since the requirements by regulatory authorities to crude biological material are becoming more stringent over time. An increasing number of such antigens capable of inducing protective humoral or cellular immune responses have been identified in the last few years. But most of these are weak immunogens. This reemphasizes the need for adjuvants to promote a potent immune response and also for delivery antigens to the immune system in an appropriate way (carrier capability). Here we review a new approach for prophylactic and therapeutic vaccines, which focuses on the induction of highly specific immune responses directed against antigen‐derived peptides using a suitable carrier system. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd.
Homogenization of degenerate second-order PDE in periodic and almost periodic environments and applications
Authors: Lions Pierre-Louis , Souganidis Panagiotis E.
Published: August 2005

We study the homogenization of fully nonlinear degenerate second-order pde, with “ellipticity” of the same order as the space oscillations, in periodic and almost periodic. As a special case we consider the class of quasi-linear, degenerate elliptic pde. The results apply to level sets equations describing the evolution of fronts with prescribed normal velocity. We also discuss an application about the averaged properties of interfacial motions in periodic and almost periodic environments.
The impact of morbid events on survival following hospitalization for complicated myocardial infarction
Authors: Dickstein Kenneth , Gleim Gilbert W. , Snapinn Steven , James Margaret K. , Kjekshus John ,   for the OPTIMAAL Study Group
Published: August 2005

Background:

Little is known about the importance of morbid events with respect to longer term survival following MI hospital discharge.

Aims:

Establish the risk of death associated with morbid events following initial discharge from MI hospitalization.

Methods:

We examined the rates of morbid events (reinfarction, stroke/TIA, revascularization, heart failure (HF) hospitalization, cardiovascular hospitalization and all‐cause hospitalization) and the relationships of these events to subsequent death in patients who survived the initial hospitalization for MI (n=5301) in the OPTIMAAL trial. Events were classified as Early (≤30 days post discharge) and Late (>30 days post discharge) for an average of 2.7 years follow‐up.

Results:

Death rates were higher in the Early period (0.20 deaths/patient year) than in the Late period (0.05 deaths/patient year). Once a morbid event, excluding revascularization, occurred, the acute hazard ratios (HR, determined by Cox regression) for death on the day of event were higher than at time periods following the event and were highest for reinfarction and stroke/TIA. The acute HRs for death for all 6 morbid events were especially high for events occurring during the Late period. The highest chronic HR for death was associated with HF and all‐cause hospitalizations. By contrast, the chronic HR for death from revascularization in both the Early (HR=0.3) and Late (HR=0.4) period indicated reduced risk.

Conclusions:

The results document event rates following hospitalization for MI, provide quantification of the associated risk for death, and may be useful in designing clinical trials. The serious morbid events examined may serve as potential surrogate endpoints in long‐term studies and identify patients that should be targeted for aggressive management.
Alternating conduction in the ischaemic border zone as precursor of reentrant arrhythmias: A simulation study
Authors: Bernus Olivier , Zemlin Christian W. , Zaritsky Roman M. , Mironov Sergey F. , Pertsov Arkady M.
Published: August 2005

Aims

Here, we investigate the mechanisms underlying the onset of conduction-related arrhythmias in a three-dimensional (3D) computational model of acute regional ischaemia.

Methods

Ischaemia was introduced by realistic gradients of potassium, pH, oxygen and electrical coupling in a 3D slab of ventricular tissue using the LRd model. We focused on a specific stage (10–15 min after occlusion) at which an intramural non-conductive ischaemic core (IC) surrounded by a border zone (BZ) has formed.

Results

At pacing frequencies greater than 4.5 Hz, we observed narrow areas (0.5 mm wide) of 2:1 conduction blocks at the periphery of the IC. As the pacing frequency increased, the area of block widened to 9 mm and gave rise to reentry at the periphery of the BZ. Alternating conduction blocks produced discordant action potential duration (APD) alternans throughout the slab and T-wave alternans in pseudo-ECG. Slowing the recovery of the calcium current broadened the range of pacing frequencies at which blocks were observed. Hyperkalaemia alone was sufficient to induce the alternating blocks.

Conclusion

Computer modelling predicts that ischaemia-related arrhythmias are triggered by calcium-mediated alternating conduction blocks in the ischaemic border zone. Alternating conduction blocks lead to intramural reentry and APD alternans.