bluuebunny/crossref_metadata_2025 huggingface dataset:
Virtuelles Bauen und partnerschaftliche Geschäftsmodelle – eine innovative Verbindung
Authors: Gralla Mike , Hanff Jochen , Schaper Dirk
Published: July 2006

Durch eine frühe Zusammenarbeit von Bauherrn, Planern und Bauunternehmen können mit partnerschaftlichen Geschäftsmodellen wesentliche Nachteile von herkömmlichen Geschäftsbeziehungen im Bauwesen aufgelöst werden. Die enge Zusammenarbeit in einer frühen Phase eines Bauvorhabens ermöglicht eine fachübergreifende Optimierung hinsichtlich Planung, Bauausführung und Nutzung einer Immobilie.

Hierbei sind die Methoden des virtuellen Bauens zweckmäßige Hilfsmittel, um die Koordination des Projekts und die Kommunikation zwischen den an einem Bauvorhaben beteiligten Partnern zu verbessern. Deshalb hat sich insbesondere bei partnerschaftlichen Geschäftsmodellen, die eine Preconstruction‐Phase enthalten, die Verwendung von virtuellem Bauen als besonders wirksam erwiesen. Virtuelles Bauen unterstützt die Optimierung eines Bauwerks und hilft bei der anschaulichen Kommunikation von Optimierungsergebnissen durch die Visualisierung mit interaktiven Computermodellen.

Virtual Design and Construction (ViCon) führt das virtuelle Bauen in die tägliche Planungs‐ und Baupraxis ein und ist eine Schlüsseltechnologie des Bauwesens. ViCon wird in der Praxis bei zahlreichen Projekten eingesetzt, die mit dem partnerschaftlichen Geschäftsmodell PreFair durchgeführt werden. In diesem Beitrag werden die Einsatzmöglichkeiten von ViCon an ausgewählten Beispielen dargestellt.
Über die Korrelation der ödometrischen und der “dynamischen” Steifigkeit nichtbindiger Böden
Authors: Wichtmann Torsten , Triantafyllidis Theodor
Published: July 2006

Der “dynamische” Schubmodul Gdyn des Bodens, d. h. die Sekantensteifigkeit der Schubspannungs‐Scherdehnungs‐Hysterese bei sehr kleinen Dehnungsamplituden, wird häufig mit Hilfe eines Diagramms abgeschätzt, welches den dynamischen Steifemodul Es,dyn mit dem Steifemodul Es bei ödometrischer Kompression (Erstbelastung) korreliert. Die Anwendungsvoraussetzungen und ‐grenzen dieser Korrelation sind jedoch nicht klar. Im Rahmen dieses Beitrags wird die Korrelation Es ↔ Es,dyn für vier Sande mit unterschiedlichen Korngrößenverteilungskurven überprüft. Zu diesem Zweck wurden Ödometerversuche und Messungen der Kompressionswellengeschwindigkeit in einer Triaxialzelle durchgeführt. Zum Teil ergaben sich deutliche Abweichungen der Meßwerte vom bisher verwendeten Korrelationsansatz. Auf der Basis der Wellenmessungen und ergänzender Resonant‐Column‐Versuche diskutiert dieser Beitrag weiterhin die “dynamische” Querdehnzahl ν und gibt eine modifizierte Korrelation Es ↔ Gdyn an.
Bemessung der Bügel, Querkraftzulagen und Schrägstäbe nach DIN 1045‐1 und nach EC2
Authors: Friedrich Richard
Published: July 2006

Der Beitrag behandelt die Querkraftbemessung von Bauteilen aus normalfestem Normalbeton C20/25 bis C50/60 und Betonstahl BSt 500. Die grafischen Hilfsmittel erleichtern die Ermittlung der notwendigen Bügel und Querkraftzulagen (ohne Umschließung der Längsbewehrung) sowie der Schrägstäbe unter 45°, in beliebiger Kombination. Desgleichen kann die Tragfähigkeit der Druckstreben überprüft und das Versatzmaß der Zugkraftlinie bestimmt werden.
Three steps in the thermal unfolding of F‐actin: An experimental evidence
Authors: Gicquaud Claude R. , Heppell Benoit
Published: July 2006

The development of differential scanning calorimetry has resulted in an increased interest in studies of the unfolding process in proteins with the aim of identifying domains and interactions with ligands or other proteins. Several of these studies were done with actin and showed that the thermal unfolding of F‐actin occurs in at least three steps; this was interpreted as the denaturation of independent domains. In the present work, we have followed the thermal unfolding of F‐actin using differential scanning calorimetry (DSC), CD spectroscopy, and probe fluorescence. We found that the three steps revealed through DSC are not the denaturation of independent domains. These three steps are a change in the environment of cys 374 at 49.5°C; a modification at the nucleotide‐binding site at 55°C; and the unfolding of the peptide chain at 64°C. Previous interpretations of the thermograms of F‐actin were thus erroneous. Since DSC is now widely used to study proteins, our experimental approach and conclusions may also be relevant in denaturation studies of proteins in general. © 2006 Wiley Periodicals, Inc. Biopolymers 83:374–380, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Li+ Ion Attachment to Chloromethyl and Chlorofluoromethyl Peroxyl Radicals: Structures and Properties of CHnCl3−nO2‐Li+ and CFnCl3−nO2‐Li+ (n=0–3) Complexes
Authors: Cheng Shuang , Li Hai‐Yang , Liu Ying
Published: July 2006

The structures and stabilities of these still experimentally unknown CHnCl3−nO2‐Li+ and CFnCl3−nO2‐Li+ ions have been theoretically investigated by ab initio molecular orbital theory and density functional theory (DFT) in conjunction with the 6‐311G(d,p), 6‐311+G(d,p), 6‐311+G(2d,p) and 6‐311+G(2df,2p) basis sets. The optimized geometries, chemical bonding and NBO analysis indicate that these complexes of CHnCl3−nO2‐Li+ and CFnCl3−nO2‐ Li+ exist as ion‐dipole molecules. The calculated affinity energies of these species exceed 41.9 kJ/mol, which are large enough to suggest the possibility that these title complexes could be detected as stable species in gas phase by Li+ ion attachment mass spectrometry.
Thalidomide therapy in adult patients with myelodysplastic syndrome
Authors: Moreno‐Aspitia Alvaro , Colon‐Otero Gerardo , Hoering Antje , Tefferi Ayalew , Niedringhaus Robert D. , Vukov Allen , Li Chin‐Yang , Menke David M. , Geyer Susan M. , Alberts Steven R. ,   For the North Central Cancer Treatment Group
Published: July 2006

BACKGROUND.

Thalidomide has shown promise for the treatment of patients with myelodysplastic syndrome. The current prospective multicenter study examined the efficacy and toxicity of thalidomide in adult patients with myelodysplastic syndrome.

METHODS.

Using the International Prognostic Scoring System (IPSS), patients were stratified into 2 groups: favorable (IPSS score, 0–1.0) or unfavorable (IPSS score, 1.5–3.5). Seventy‐two patients (42 of whom were favorable and 30 of whom were unfavorable) received a starting dose of oral thalidomide of 200 mg daily. The dose was increased by 50 mg per week to a targeted maximum daily dose of 1000 mg.

RESULTS.

According to the International Working Group response criteria for myelodysplastic syndrome, 1 patient in the unfavorable group achieved a partial remission with a complete cytogenetic response. Overall, 2 patients (5%) in the favorable group and 4 patients (14%) in the unfavorable group experienced either a hematologic improvement or a partial response. The most frequent Grade 3 or 4 (grading was based on the National Cancer Institute's Common Toxicity Criteria [version 2.0]) nonhematologic adverse events were fatigue (24%), infection (19%), neuropathy (13%), dyspnea (8%), and constipation (7%).

CONCLUSIONS.

Thalidomide alone, at the schedule and dose levels used in the current study, is not a safe and viable therapeutic option for patients with myelodysplastic syndrome. Limited efficacy and increased toxicity were observed in the current Phase II trial. Cancer 2006. © 2006 American Cancer Society.
Differences in survival among patients with urachal and nonurachal adenocarcinomas of the bladder
Authors: Wright Jonathan L. , Porter Michael P. , Li Christopher I. , Lange Paul H. , Lin Daniel W.
Published: July 2006

BACKGROUND

Primary adenocarcinomas of the bladder and urachus are rare malignancies, and knowledge of the patient demographics, pathologic characteristics, and survival associated with these tumors is poor. The current study compares disease‐specific characteristics and survival associated with urachal and nonurachal primary bladder adenocarcinomas.

METHODS

Incident cases of urachal and nonurachal primary adenocarcinomas of the bladder were identified from the Surveillance, Epidemiology, and End Results (SEER) Program. Demographic and pathologic characteristics at the time of diagnosis were compared. Risks of mortality among urachal and nonurachal primary adenocarcinomas of the bladder were compared using multivariate Cox regression.

RESULTS

A total of 151 urachal and 1374 nonurachal adenocarcinomas of the bladder patients were identified. Compared to those with nonurachal tumors, patients with urachal adenocarcinoma were more likely to be younger (median age, 56 vs. 69 years, P < .0001) and female (45% vs. 36%, P = .02). Urachal lesions were less likely to be high grade (35% vs. 66%, P<.001), but more likely to involve distant metastases (30% vs. 15%, P < .001). Partial cystectomy was more common in urachal tumors (66% vs. 16%, P < .001). In multivariate analysis, subjects with urachal tumors had a lower risk of all cause (hazard ratio [HR] = 0.56, 95% confidence interval [CI]: 0.38–0.83) and disease‐specific (HR = 0.59, 95% CI: 0.35–0.98) mortality compared with patients with nonurachal tumors.

CONCLUSIONS

Urachal adenocarcinomas represent 10% of all primary adenocarcinomas of the bladder. Overall and disease‐specific mortality risks are improved in patients with urachal lesions, even after controlling for numerous patient and tumor characteristics. Cancer 2006. © 2006 American Cancer Society.
Urachal carcinoma: Clinicopathologic features and long‐term outcomes of an aggressive malignancy
Authors: Ashley Richard A. , Inman Brant A. , Sebo Thomas J. , Leibovich Bradley C. , Blute Michael L. , Kwon Eugene D. , Zincke Horst
Published: July 2006

BACKGROUND.

Urachal carcinoma (UrC) is a rare malignancy, and patients with this disease have a poor prognosis. In this article, the authors report 50 years of experience with this tumor at the Mayo Clinic.

METHODS.

A urachal mass was described in 130 patients, and 66 of those masses were malignant. The authors identified multivariate predictors of malignancy in clinically diagnosed urachal masses and predictors of UrC‐specific survival. This report presents a novel 4‐category staging system for UrC along with the treatment history of this tumor and the results of salvage therapy.

RESULTS.

Twenty women and 46 men were identified with UrC. The strongest predictors of malignancy in a urachal mass were hematuria and age older than 55 years. The 5‐year cancer‐specific survival rate was 49%. The new Mayo staging system was less complicated than the Sheldon system, although both systems predicted cancer‐specific mortality equally well. Positive surgical margins (hazard ratio [HR], 4.7), high tumor grade (HR, 3.6), positive local lymph nodes (HR, 5.1), metastases at diagnosis (HR, 3.3), advanced tumor stage (HR, 4.8), failure to perform umbilectomy (HR, 3.0), and primary radiation therapy (HR, 2.9) were all univariately associated with death (P < .05). Only grade and margins were significant in the multivariate analysis. No survival benefit was noted for lymphadenectomy or adjuvant therapy. Salvage surgery resulted in a long‐term cure for 50% of patients who had local recurrences. No effective treatment was identified for patients with metastatic UrC.

CONCLUSIONS.

Early and complete extended partial cystectomy, including umbilectomy, is critical to the survival of patients with UrC. The authors recommend using the Mayo staging system in future studies because of its simplicity. The current results indicated that the most important predictors of prognosis were tumor grade and surgical margin status. Cancer 2006. © 2006 American Cancer Society.
Ruthenium Films Deposited by Liquid‐Delivery MOCVD Using Bis(ethylcyclopentadienyl)ruthenium with Toluene as the Solvent
Authors: Hur'yeva T. , Lisker M. , Burte E. P.
Published: July 2006

Pure ruthenium thin films are prepared by liquid‐delivery metal‐organic (MO)CVD using bis(ethylcyclopentadienyl)ruthenium (Ru(EtCp)2) with toluene as the solvent. The deposition of Ru thin films is carried out on various substrates at temperatures in the range 330–460 °C via the oxygen‐assisted pyrolysis of Ru(EtCp)2. Ru in a single phase can be obtained under all growth conditions. The reaction kinetics, film composition, film morphology, mechanical properties, and electrical properties of deposited Ru films were investigated. The films obtained have a low resistivity value of 20 μΩ cm, low stress values of about 70 MPa, and a preferred crystalline orientation (002), offering potential application in storage‐capacitor electrodes.
Thin, Continuous, and Conformal Copper Films by Reduction of Atomic Layer Deposited Copper Nitride
Authors: Li Z. , Gordon R. G.
Published: July 2006

Thin and continuous copper films serve as seed layers for electrodeposition of interconnects in microelectronic devices. Gaps in the continuity of these Cu films must be avoided, because they can generate voids that later lead to failure of the devices. It is difficult to sputter completely continuous copper‐seed layers into the increasingly narrow trenches and holes in modern interconnects. Here we report a method for producing thin, completely continuous, and highly conductive copper films conformally inside very narrow holes with aspect ratios of over 40:1. The first step in our process is atomic layer deposition (ALD) of copper(I) nitride, Cu3N, by the alternating reactions of copper(I) N,N′‐di‐sec‐butylacetamidinate vapor and ammonia on surfaces heated to approximately 160 °C. At this temperature, Cu3N is thermally stable, but is readily reduced to copper metal by exposure to molecular hydrogen gas (H2). Copper layers as thin as 0.8 nm (about 3 monolayers) are electrically continuous and show the electrical resistivity predicted by a grain‐boundary‐scattering model for continuous films of that thickness. 3 nm thick copper films on 2 nm of ruthenium have a sheet resistance of less than 50 Ω/□, a value low enough to serve as seed layers for advanced electroplating techniques.
Lymphopenia‐driven CD8+ T cells are resistant to antigen‐induced tolerance in NOD.scid mice
Authors: Long Brian , Wong Carmen P. , Wang Yaming , Tisch Roland
Published: July 2006

T cells undergoing lymphopenia‐driven proliferation acquire effector and memory properties that can be pathogenic. Indeed, generalized lymphopenia is associated with a variety of autoimmune diseases such as type 1 diabetes. The current study was carried out to determine how CD8+ T cells undergoing acute lymphopenic expansion respond to antigen under tolerizing conditions in vivo. Adoptive transfer of diabetes by TCR‐transgenic CD8+ T cells was enhanced following treatment of NOD. scid recipients with a high dose of soluble peptide. Furthermore, whereas TCR‐transgenic CD8+ T cells underwent clonal deletion and failed to differentiate into CTL in peptide‐treated lymphoreplete recipient mice, TCR‐transgenic CD8+ T cells in a lymphopenic environment were resistant to clonal deletion, and CTL differentiation was enhanced by a high dose of soluble peptide. Moreover, peptide treatment had distinct effects on expression of the anti‐apoptotic protein Bcl‐XL in TCR‐transgenic CD8+ T cells under lymphopenic versus lymphoreplete conditions. These results demonstrate that CD8+ T cells undergoing lymphopenia‐driven expansion in NOD. scid recipients are resistant to antigen‐induced tolerance, and readily differentiate into CTL upon stimulation with a high dose of soluble peptide.
Role of human papillomavirus in the etiology of head and neck cancer
Authors: Tran Nham , Rose Barbara R. , O'Brien Christopher J.
Published: July 2006

Head and neck cancer is the world's sixth most common cancer, but despite advances in treatment, there has been no significant decline in the mortality rate. In recent years, there has been mounting epidemiologic and experimental evidence of a role for human papillomavirus (HPV) as the etiologic agent of a subset of head and neck cancers. The association is strongest for oropharyngeal cancers, especially those of the tonsil. HPV 16 is invariably the predominant type. HPV‐positive cancers have been shown to be biologically distinct, clustering among nonsmokers and light drinkers, and have been associated with a favorable prognosis. This review examines the current findings of HPV in head and neck cancers and discusses implications for developing new treatments. © 2006 Wiley Periodicals, Inc. Head Neck, 2006
Role of birthweight in the etiology of breast cancer
Authors: Michels Karin B. , Xue Fei
Published: July 2006

Breast cancer may originate in utero. We reviewed the available evidence on the association between birthweight and the risk of breast cancer. To date, 26 research papers addressing this issue have been published. The majority of studies identified a positive link between birthweight and premenopausal, but not postmenopausal, breast cancer. The relative risk estimate for breast cancer comparing women with high birthweight to women with low birthweight combining all studies including both pre‐ and postmenopausal breast cancer was 1.23 (95% confidence interval 1.13–1.34). The mechanisms underlying this association likely include elevated levels of growth factors that may increase the number of susceptible stem cells in the mammary gland or initiate tumors through DNA mutations. Loss of imprinting (LOI) of growth hormone genes relevant for intrauterine growth, such as insulin‐like growth factor 2 (IGF2), leads to abnormally high levels of these hormones evidenced by high birthweight. LOI of IGF2 has also been found in mammary tumor tissue. The role of environmental factors that stimulate such epigenetic regulation of gene expression remains to be elucidated. © 2006 Wiley‐Liss, Inc.
Mutations in DNA polymerase η are not detected in squamous cell carcinoma of the skin
Authors: Glick Eitan , White Lisa M. , Elliott Nathan A. , Berg Daniel , Kiviat Nancy B. , Loeb Lawrence A.
Published: July 2006

The major etiological agent in skin cancer is exposure to UV‐irradiation and the concomitant DNA damage. UV‐induced DNA lesions, such as thymine dimers, block DNA synthesis by the major DNA polymerases and inhibit the progression of DNA replication. Bypass of thymine dimers and related lesions is dependent on the translesion polymerase DNA polymerase η (Polη). In the inherited disorder, xeroderma pigmentosum variant (XPV), inactivation of Polη results in extreme sensitivity to UV light and a marked increase in the incidence of skin cancer. Here, we tested the hypothesis that somatic mutations and/or polymorphisms in the POLH gene that encodes Polη are associated with the induction of UV‐dependent skin cancers. We sequenced the exonic regions of the Polη open reading frame in DNA from 17 paired samples of squamous cell skin carcinoma and adjacent histologically normal tissue. We analyzed approximately 120,000 nucleotides and detected no mutations in POLH in the tumors. However, we identified 6 different single‐nucleotide polymorphisms, 3 of them previously undocumented, which were present in both the tumor and paired normal tissue. We conclude that neither mutations nor polymorphisms in the coding regions of POLH are required for the generation of human skin squamous cell carcinoma. © 2006 Wiley‐Liss, Inc.
In vitro characterization of a calcium sulfate/PLLA composite for use as a bone graft material
Authors: Mamidwar Sachin S. , Arena Christopher , Kelly Shawn , Alexander Harold , Ricci John
Published: July 2006

A study was conducted to characterize the dissolution, morphology, and chemical composition of a calcium sulfate/poly (L‐lactic acid) (CS/PLLA) composite material before and after immersion in simulated body fluid (SBF). Twelve groups of experimental samples were prepared by coating CS pellets 1, 2, 3, or 4 times with one of three concentrations of a PLLA solution and wrapping them in mesh; CS pellets for use as controls were similarly prepared but not coated. The PLLA coating added from 1 to 22% to the weight of experimental pellets; scanning electron microscopy revealed that the coating thickness ranged from 2 to 50 μm depending on the concentration of the coating solution and the number of coatings. All samples were immersed in SBF for up to 97 days. After immersion, the experimental coatings thinned out, small cracks and holes formed in the coating, and the coating became roughened. Mean dissolution rates for each of the 12 CS/PLLA groups were significantly lower than those of uncoated CS pellets; among CS/PLLA groups, dissolution rates varied according to concentration of the coating solution and number of coatings. The half‐life of pure CS pellets was 19 days whereas the half‐life of CS/PLLA composite pellets ranged from 30 to 70 days. X‐ray microprobe analysis of experimental pellets after immersion in SBF revealed that mineralization occurred in the CS portion of these pellets as well as on the coating; most of the mineral was calcium phosphate, most of which was on the coating. Further studies will be required to confirm this composite's promise as a clinically effective osteoconductive material. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Proton affinities of maingroup‐element hydrides and noble gases: Trends across the periodic table, structural effects, and DFT validation
Authors: Swart Marcel , Rösler Ernst , Bickelhaupt F. Matthias
Published: July 2006

We have carried out an extensive exploration of the gas‐phase basicity of archetypal neutral bases across the periodic system using the generalized gradient approximation (GGA) of the density functional theory (DFT) at BP86/QZ4P//BP86/TZ2P. First, we validate DFT as a reliable tool for computing proton affinities and related thermochemical quantities: BP86/QZ4P//BP86/TZ2P is shown to yield a mean absolute deviation of 2.0 kcal/mol for the proton affinity at 298 K with respect to experiment, and 1.2 kcal/mol with high‐level ab initio benchmark data. The main purpose of this work is to provide the proton affinities (and corresponding entropies) at 298 K of the neutral bases constituted by all maingroup‐element hydrides of groups 15–17 and the noble gases, that is, group 18, and periods 1–6. We have also studied the effect of step‐wise methylation of the protophilic center of the second‐ and third‐period bases. © 2006 Wiley Periodicals, Inc. J Comput Chem 27: 1486–1493, 2006
Diffusion tensor imaging in evaluation of human skeletal muscle injury
Authors: Zaraiskaya Tatiana , Kumbhare Dinesh , Noseworthy Michael D.
Published: July 2006

Purpose

To explore the capability and reliability of diffusion tensor magnetic resonance imaging (DTI) in the evaluation of human skeletal muscle injury.

Materials and Methods

DTI of four patients with gastrocnemius and soleus muscles injuries was compared to eight healthy controls. Imaging was performed using a GE 3.0T short‐bore scanner. A diffusion‐weighted 2D spin echo echo‐planar imaging (EPI) pulse sequence optimized for skeletal muscle was used. From a series of axially acquired diffusion tensor images the diffusion tensor eigenparameters (eigenvalues and eigenvectors), fractional anisotropy (FA), and apparent diffusion coefficient (ADC) were calculated and compared for injured and healthy calf muscles. Two dimensional (2D) projection maps of the principal eigenvectors were plotted to visualize the healthy and pathologic muscle fiber architectures.

Results

Clear differences in FA and ADC were observed in injured skeletal muscle, compared to healthy controls. Mean control FA was 0.23 ± 0.02 for medial and lateral gastrocnemius (mg and lg) muscles, and 0.20 ± 0.02 for soleus (sol) muscles. In all patients FA values were reduced compared to controls, to as low as 0.08 ± 0.02. The ADC in controls ranged from 1.41 to 1.31 × 10–9 m2/second, while in patients this was consistently higher. The 2D projection maps revealed muscle fiber disorder in injured calves, while in healthy controls the 2D projection maps show a well organized (ordered) fiber structure.

Conclusion

DTI is a suitable method to assess human calf muscle injury. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
HPLC separation of amino acid enantiomers and small peptides on macrocyclic antibiotic‐based chiral stationary phases: A review
Authors: Ilisz István , Berkecz Róbert , Péter Antal
Published: July 2006

The search for new and effective chiral selectors capable of separating a wide variety of enantiomeric compounds is an ongoing process. In the past decade, macrocyclic antibiotics have proved to be an exceptionally useful class of chiral selectors for the separation of enantiomers of biological and pharmacological importance by means of HPLC, TLC and electrophoresis. More chiral analytes have been resolved through the use of glycopeptides than with all the other macrocyclic antibiotics combined (ansamycins, thiostrepton, aminoglycosides, etc.). The glycopeptides avoparcin, teicoplanin, ristocetin A and vancomycin have been extensively used as chiral selectors in the form of chiral bonded phases in HPLC, and HPLC stationary phases based on these glycopeptides have been commercialized. Teicoplanin, vancomycin, their analogs and ristocetin A seem to be the most useful glycopeptide HPLC bonded phases for the enantioseparation of proteins and unusal native and derivatized amino acids. In fact, the macrocyclic glycopeptides are to some extent complementary to one another: where partial enantioresolution is obtained with one glycopeptide, there is a high probability that baseline or better separation can be obtained with another. This review sets out to characterize the physicochemical properties of these antibiotics and their application in the enantioseparations of amino acids. The mechanism of separation, the sequence of elution of the stereoisomers and the relation to the absolute configuration are also discussed.
Monitoring pitting‐crevice corrosion using the WBE‐noise signatures method
Authors: Aung N.N. , Tan Y.‐J.
Published: July 2006

An electrochemically integrated multi‐electrode array namely the wire beam electrode (WBE) and noise signatures analysis have been applied in novel combinations to study crevice corrosion behaviour in the presence of pits. Characteristic electrochemical noise signatures were found to correlate with characteristic changes in WBE current distribution maps, which indicate corrosion rates distributions, corrosion patterns and the degree of pitting and crevice corrosion. Specifically, two characteristic noise patterns were observed: (i) the characteristic noise pattern of quick potential changes towards more negative direction with no recovery (termednoise signature I) was found to correspond with the initiation and stabilization of the anode inside crevice; and (ii) the characteristic noise pattern of the cyclic potential oscillation at a constant frequency (termednoise signature II) was found to correspond with the stable anodic dissolution in the occluded cavity site in WBE current distribution maps. A new parameter namely the localization parameter (LP) has been proposed to describe the degree of localization. The LP for crevice corrosion was found to be low compared to that for pitting corrosion.
Corrosion fatigue of weld‐bonded austenitic stainless steels in 3.5% NaCl solution
Authors: Somervuori M. E. , Alenius M. T. , Kosonen T. , Karppi R. , Hänninen H. E.
Published: July 2006

Corrosion fatigue and fatigue properties of weld‐bonded and spot‐welded austenitic stainless steels EN 1.4301 and EN 1.4318 in 2B or 2F and 2H conditions were investigated. The corrosive environment was 3.5% NaCl solution at + 50 °C. In air the fatigue strengths of the weld‐bonded single spot lap‐jointed specimens were significantly higher than those of the spot‐welded specimens used as reference. In the corrosive environment the difference was markedly reduced. The failure mode of the weld‐bonded specimens was adhesive in the corrosive environment and cohesive in air. The difference in the failure mode of the weld‐bonded joints did not affect the fatigue crack initiation in stainless steels, which always occurred at the outer edge of the corona bond area.
Surface Modification of Polyimide Membranes by Diamines for H2 and CO2 Separation
Authors: Chung Tai‐Shung , Shao Lu , Tin Pei Shi
Published: July 2006

Summary: The separation of H2/CO2 is technologically important to produce the next generation fuel source, hydrogen, from synthesis gas. However, the separation efficiency achieved by polymeric membranes is usually very low because of both unfavourable diffusivity selectivity and solubility selectivity between H2 and CO2. A series of novel diamino‐modified polyimides has been discovered to enhance the separation capability of polyimide membranes especially for H2 and CO2 separation. Both pure gas and mixed gas tests have been conducted. The ideal H2/CO2 selectivity in pure gas tests is 101, which is far superior to other polymeric membranes and is well above the Robeson's upper‐bound curve. Mixed gas tests show an ideal selectivity of 42 for the propane‐1,3‐diamine‐modified polyimide. The lower selectivity is a result of the sorption competition between H2 and the highly condensable CO2 molecules. However, both pure gas and mixed gas data are better than other polymeric membranes and above the Robeson's upper‐bound curve. It is evident that the proposed modification methods can alter the physicochemical structure of polyimide membranes with superior separation performance for H2 and CO2 separation.

Both pure gas and mixed gas separation properties of H2/CO2 for membranes derived from 6FDA‐durene with respect to the upper‐bound curve.

magnified image

Both pure gas and mixed gas separation properties of H2/CO2 for membranes derived from 6FDA‐durene with respect to the upper‐bound curve.
Synthesis of a New PHEMA/PEO Enzymatically Biodegradable Hydrogel
Authors: Khelfallah Nawel S. , Decher Gero , Mésini Philippe J.
Published: July 2006

Summary: We report the synthesis of a new enzymatically degradable gel based on PHEMA and PEO crosslinking macromonomer. The crosslinker contains the tripeptide sequence Gly‐Gly‐Leu, which is a substrate for proteases such as subtilisin or chymotrypsin. The crosslinker was obtained by the coupling reaction of succinyl‐glycyl‐glycyl‐leucine with 2‐aminoethyl‐terminated PEO chains ($\overline M _{\rm w}$ = 3 400) and subsequent esterification of the hydroxyl endgroup with methacryloyl chloride. It was characterized by SEC and 1H NMR. Enzymatic cleavage of the crosslinking macromonomer was showed by SEC. The macromonomer was copolymerized with HEMA to yield hydrogel that is stable in a physiological buffer. Enzymatic assay showed that this gel is degraded in the presence of a bacterial protease (subtilisin). The degradation is complete within 50 d at 37 °C. This new gel is a good candidate for drug‐delivery systems where the release can be triggered by the presence of bacterial proteases.

PHEMA crosslinked with MA‐PEG‐SucGGL‐PEO‐MA and its degradation by subtilisin.

magnified image

PHEMA crosslinked with MA‐PEG‐SucGGL‐PEO‐MA and its degradation by subtilisin.
Cover Picture: Macromol. Rapid Commun. 13/2006
Authors: Chung Tai‐Shung , Shao Lu , Tin Pei Shi
Published: July 2006

Cover: Novel chemical modifications have been proposed by a series of linear diamines on polyimides to overcome the low H2/CO2 selectivity of traditional polymers for H2 purification. The resultant membranes show extremely impressive H2/CO2 selectivity for both mixed and pure gas tests, opening a new way for H2 generation during the world‐wide energy crisis. Further details can be found in the article by T.‐S. Chung,* L. Shao, and P. S. Tin on page 998.
Multi‐criteria optimization of ball passing in simulated soccer
Authors: Kyrylov Vadim , Bergman David S. , Greber Martin
Published: July 2006

Simulated soccer offers a standard real‐time environment for testing decision‐making methods for multi‐agent systems. One critical task is determining to which team‐mate the ball should be passed and the optimal point where this ball should be sent. Early methods based on enforced learning or heuristics tried to aggregate anticipated risks and pay‐offs instead of flexibly balancing them. That was because scholars were not treating ball passing as a multi‐criteria optimization problem in its classic sense. We propose a set of three criteria, tactical gain and two time balances, which should be balanced while selecting an optimal point on the field for passing the ball to. One of the advantages of this set of criteria is that they are treating direct and leading passes in the same way, thus offering a unified method for ball passing.

In order to make this problem tractable, the continuous decision parameter space is replaced by a finite set of N points on the XY‐plane, which are carefully selected using some heuristics. This set is searched for non‐dominated alternatives, of which one alternative is further selected. The selection is based on the relative importance of the criteria supplied by the developer of the soccer agent. The selection method is original and uses sequential elimination of poor alternatives with respect to one criterion. Criteria are applied randomly, with the probabilities proportional to their relative importance.

Experiments have shown that the multi‐criteria decision‐making algorithm is superior to its heuristic‐based counterpart. Furthermore, we suggest that it might be implemented in the RoboCup leagues dealing with physical robots. Copyright © 2006 John Wiley & Sons, Ltd.
UniComBOS—Intelligent Decision Support System for multi‐criteria comparison and choice
Authors: Ashikhmin I. , Furems E.
Published: July 2006

This paper discusses the main ideas of a new approach to discrete multi‐criteria comparison and choice from a small set of alternatives and its implementation as the Intelligent Decision Support System (IDSS) UniComBOS. The approach has been developed within the Verbal Decision Analysis paradigm. While seeking to use psychologically correct information on a decision maker's (DM's) preferences, the approach allows to take into account the individual DM's ability to deal with multi‐criteria alternatives. This is facilitated by a special graphical user interface, using colour differentiation of preferences, which assists a DM in making comparisons and provides the possibility for additional checks on the consistency of her/his answers. As in most multi‐criteria decision‐making aids, multi‐criteria descriptions of the alternatives are decomposed into their parts upon the least possible number of criteria (‘units’). The DM makes pair‐wise comparison starting from single‐criterion ‘units’, and then the number of criteria in a ‘unit’ is incremented one‐by‐one, until either the best alternative is found by the newly introduced rule of U‐Dominance, or it is obvious that the comparison of the given multi‐criteria ‘units’ poses a great challenge to the DM. In the latter case, the system would not be able to find the single best alternative, but it will indicate a set of alternatives that are incomparable with each other and that are preferable for DM in comparison to any alternative not included in this set. Copyright © 2006 John Wiley & Sons, Ltd.
1H and 13C assignments of cyclo[N‐(Lys‐Phe)‐Orn‐Val], a semicyclic imide tetrapeptide from Burkholderia cepacia
Authors: Pérez‐Picaso Lemuel , Rios María Yolanda , Hernández Ana Niurka , Martínez Jorge
Published: July 2006

The rhizobacteria Burkholderia cepacia biosynthesized the new tetrapeptide Cyclo[N‐(Lys‐Phe)‐Orn‐Val] (1), a 2,5‐diketopiperazine, and the known siderophore azurechelin (salicylic acid). The structure of 1 was established by means of IR, UV, 1H and 13C NMR, double dimension experiments and MS. Copyright © 2006 John Wiley & Sons, Ltd.
Dual‐colour chromogenic in situ hybridization for testing of HER‐2 oncogene amplification in archival breast tumours
Authors: Laakso M , Tanner M , Isola J
Published: July 2006

Chromogenic in situ hybridization (CISH), which uses an enzymatic reaction to detect the hybridized DNA probe, is a new alternative to fluorescence in situ hybridization (FISH) for the assessment of HER‐2 oncogene amplification status in breast cancer. The main advantage of CISH over FISH is the use of bright‐field microscopy, which is rapid and allows the histopathological evaluation of tumour tissue sections. The main disadvantage of CISH has been the use of a single probe, thereby making it necessary to hybridize the control probe (chromosome 17 centromere) on an adjacent tissue section. The present paper presents an efficient protocol for dual‐colour CISH (dc‐CISH) based on the co‐hybridization of probes to the HER‐2 oncogene and chromosome 17 centromere. The probes were detected sequentially with antibodies to digoxigenin and biotin and with secondary antibody polymers labelled with horseradish peroxidase and alkaline phosphatase. The peroxidase reaction was visualized with tetramethyl benzidine (green reaction product) and the alkaline phosphatase reaction with New Fuchsin (red reaction product). The accuracy of the method was verified by comparing the results for four cell lines and 40 tumour samples with those obtained using FISH (Vysis Inc.). The results of FISH and dc‐CISH showed high concordance (91%, Kappa coefficient = 0.82). It is concluded that dual‐colour CISH, which is a new alternative to FISH enables the assessment of copy number ratio (HER‐2/17 centromere) in conjunction with proper histopathological evaluation and the ease of bright‐field microscopy. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Ultraviolet‐inactivated human cytomegalovirus induces placental syncytiotrophoblast apoptosis in a Toll‐like receptor‐2 and tumour necrosis factor‐α dependent manner
Authors: Chan G , Guilbert LJ
Published: July 2006

Placentae obtained from newborns with congenital human cytomegalovirus (HCMV) infection often display chronic villitis and disruptions of the syncytiotrophoblast (ST). Little is known about how HCMV infection induces inflammation in the villous placenta and loss of the trophoblast. We propose that the inflammation is initiated with innate defence responses of the ST to maternal blood‐borne virus. In this paper we show with a culture model (ST derived from primary cytotrophoblasts) that UV‐inactivated HCMV (UV‐HCMV) doubled the frequency of ST apoptosis. ST cultures challenged with UV‐HCMV increased transcription and secretion of the inflammatory cytokines tumour necrosis factor α (TNFα) and interleukin‐8, and antibody to TNFα inhibited UV‐HCMV‐induced apoptosis. Treatment with cycloheximide, an inhibitor of protein translation, did not reduce UV‐HCMV‐induced TNFα gene transcription, indicating that upregulation was independent of de novo protein synthesis. Neutralizing antibody to Toll‐like receptor (TLR)2 inhibited UV‐HCMV‐induced transcription and translation of TNFα, and consequently inhibited the increase in ST apoptosis. Our results show that even transcriptionally inactive HCMV binding to TLR2 on ST can initiate inflammation, including secretion of TNFα, which leads to trophoblast death. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Development of nanoparticle–polysiloxane composites for spacecraft applications
Authors: Hidden G. , Boudou L. , Martinez‐Vega J. , Remaury S. , Nabarra P.
Published: July 2006

In orbit, satellites are exposed to significant thermal variations. To ensure reliable operation of their on‐board systems and equipment, a thermal control of the spacecraft is necessary using cold, neutral or warm coatings. The Materials and Coatings Laboratory of the Thermal Control Services at CNES has elaborated a cold coating version by using a polysiloxane deposit on a metal substrate (such as polished aluminum or vacuum deposited silver). In geostationary orbit, polysiloxane, which has a high electrical resistivity (>1017 Ω m), can accumulate implanted charges that can give rise to electrostatic discharges and damage the neighboring electronic systems. To prevent any electrostatic discharge problems in geostationary orbit, the resistivity of coatings should be reduced without altering their thermo‐optical properties, in particular the low solar absorptivity and the high emissivity for cold coatings. Several methods have been studied, such as the incorporation of carbon nanotubes (CNT) and indium tin oxide (ITO) nanoparticles in the polysiloxane matrix, with the objective of attaining a high transparency, a high emissive, and an antistatic resin. In this paper, the influence on thermo‐optical properties of CNT‐Polysiloxane and ITO‐Polysiloxane composites, as a function of sample thickness d (μm) and nanoparticles concentration p (%wt), is reported. POLYM. ENG. SCI., 46:1079–1084, 2006. © 2006 Society of Plastics Engineers
Conductive polypropylene/clay/polypyrrole nanocomposites
Authors: Omastová Mária , Mravc̆áková Miroslava , Chodák Ivan , Pionteck Jürgen , Häussler Liane
Published: July 2006

Nanocomposites of a new type have been prepared containing a constant amount, 4.8 wt%, of montmorillonite (MMT) in a polypropylene (PP) matrix and different amounts of conducting polypyrrole (PPy) varying from 4.8 to 16.7 wt%. For comparison, polypropylene/polypyrrole (PP/PPy) composites and MMT/PPy nanocomposites with the same composition ratio were synthesized. All polypropylene‐containing composites were synthesized in an aqueous solution of the anionic surfactant dodecylbenzenesulfonic acid (DBSA) or in water/methanol. Chemical oxidative polymerization of pyrrole was used for suspension modification of powdered PP, MMT, or mixtures of PP and MMT particles using ferric chloride as oxidant. To investigate the influence of the primary MMT particle structure on conductivity, three types of sodium MMT were used for the preparation of MMT/PPy nanocomposites. Wide angle X‐ray scattering (WAXS) studies confirmed the intercalation of conducting PPy into MMT layers. The amount of PPy influences the final conductivity of the composites and nanocomposites. The nanocomposite (PP/4.8 wt% MMT)/PPy containing 16.7 wt% PPy reaches a conductivity of 4.8 × 10−2 S cm−1, i.e. more than one order of magnitude higher than the conductivity of the clay‐free composite, PP/16.7 wt% PPy prepared as a suspension in water containing the same anionic surfactant, dodecylbenzenesulfonic acid. Thermogravimetric analysis (TGA) proved that the presence of PPy increases the thermal stability of PP/PPy composites as well as (PP/4.8 wt% MMT)/PPy nanocomposites. POLYM. ENG. SCI. 46:1069–1078, 2006. © 2006 Society of Plastics Engineers
Synthesis of polymer‐embedded noble metal clusters by thermolysis of mercaptides dissolved in polymers
Authors: Carotenuto G. , Nicolais L. , Perlo P.
Published: July 2006

Homoleptic mercaptides of noble metals (i.e., Me(SR)x, where R is a linear alkyl group, i.e., CnH2n+1) dissolved in polymer undergo a thermal degradation process at moderately low temperatures (180–250°C), producing metal atoms that then give nanosized metal particles by clustering. As an example, the preparation of palladium, gold, and silver clusters dispersed in polystyrene has been described, but such chemical route is a very general approach and a variety of metal/polymer combinations can be equivalently obtained. POLYM. ENG. SCI. 46:1016–1021, 2006. © 2006 Society of Plastics Engineers.
Axial preloading effects when reinforced concrete columns are strengthened by concrete jackets
Authors: Vandoros Konstantinos G. , Dritsos Stephanos E.
Published: July 2006

This paper investigates the effects of axial preload on concrete columns that have been strengthened by placing concrete jackets. Most of the research in the world in the area of strengthening concrete columns has been performed without taking into account preloading effects. It is normal experimental practice to apply an axial load after the construction of a jacket. In reality, preloading is the true situation when strengthening existing buildings due to service loading effects. The present paper presents experimental data so that the effects of preloading can be compared with a number of other similarly constructed and tested specimens. In addition, the results are compared to an original column and a monolithic column. A theoretical approach has been developed so that different concrete strengths, jacket strengths and applied axial loads could be converted to equivalent mechanical characteristics and axial loads and only the influence of the applied axial preload could be examined. The results showed that preloading improves the strength and the deformation capacity but decreases the initial stiffness.
Growth and characterization of bilayer InAs/GaAs quantum dot structures
Authors: Liang B. L. , Wang Zh. M. , Mazur Yu. I. , Strelchuck V. V. , Salamo G. J.
Published: July 2006

One of the difficulties in understanding energy transfer in bilayer quantum dot structures is the complex role of carrier tunneling. This limitation is due to the fact that, for most studies to date, QDs in each layer have only one confined energy level making it difficult to study resonant tunneling effects. In this work, we have investigated the low growth‐rate technique to produce dislocation‐free very large QDs in the second layer that are characterized by several confined energy levels. The high quality surface morphology and optical behavior of these structures were demonstrated by AFM and PL measurements. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of Sr adsorption on stability of and epitaxial SrTiO3 growth on Si(001) surface
Authors: Liang Y. , Gan S. , Wei Y. , Gregory R.
Published: July 2006

The geometric and electronic structures of the Sr adsorbed Si(001) surface were investigated using photoemission spectroscopy, electron diffraction, scanning tunneling microscopy, and Rutherford backscattering spectrometry. Results showed that the Sr adsorbed Si(001) exhibited several reconstructions depending upon the Sr coverage. Photoemission results revealed that at one half mono‐layer of Sr coverage the dimer‐derived surface states disappeared and the stability of Si increased accordingly against oxidation at elevated temperatures. Using this Sr covered surface as a template, epitaxial SrTiO3 films were grown on the vicinal Si(001) substrates using molecular beam epitaxy. The growth process is explained in terms of kinetically limited reaction facilitated by a local energy minimum induced by the Sr adsorption at Si(001) surface. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low‐complexity linear group‐SIC detectors
Authors: Bentrcia A. , Zerguine A. , Sheikh A. U.
Published: July 2006

In this paper, we consider a linear group polynomial expansion successive interference cancellation (GPE‐SIC) detector in a synchronous CDMA system. It is a hybrid detector, which combines parallel and successive cancellation techniques in order to extract the advantages of both schemes. We use the fact that even if the cross‐correlation matrix of the system is not diagonal dominant, the sub‐matrices corresponding to different groups can be forced to be diagonal dominant by suitable grouping of users to approximate the decorrelator/MMSE detector by a low‐complexity polynomial expansion detector. The latter is computationally very efficient if the cross‐correlation matrix of users within the same group is diagonal dominant.

Simulation results showed that the (GPE‐SIC) detector has the same performance as the linear group decorrelator successive interference cancellation (GDEC‐SIC) detector but with low‐computational complexity. Copyright © 2006 John Wiley & Sons, Ltd.