bluuebunny/crossref_metadata_2025 huggingface dataset:
Guest‐Driven Luminescence: Lanthanide‐Based Host–Guest Systems with Bimodal Emissive Properties Based on a Guest‐Driven Approach
Authors: Wang Ping , Ma Jian‐Ping , Dong Yu‐Bin
Published: September 2009

A series of discrete closed, semi‐closed, and polymeric lanthanide‐based [{Ln(H2O)8}3+⊂LnIII2L4] host–guest systems with tetragonal prism‐like structure have been designed and synthesized through the ligand‐dominated approach. These nanoscopic cages are robust and can be maintained upon guest exchange. Within the restricting space, the luminescence intensity of the encapsulated [Ln(H2O)8]3+ species is dramatically enhanced due to the vibrational movements originating from the OH oscillators in the coordinated water molecules being effectively reduced by the host–guest H‐bonding interactions. Based on the guest‐driven approach, tunable emission and bimodal emission (UV/Vis/NIR) of these [{Ln(H2O)8}3+⊂LnIII2L4] supramolecular systems are successfully realized. Moreover, the strong luminescence originating from [{Ln(H2O)8}3+⊂LnIII2L4] host–guest system can be quenched by encapsulation of d‐block metal quenchers, such as Fe3+ and Cu2+, through solid‐state f–d metal exchange. Additionally, this study demonstrates that the photoinduced solid‐state guest‐independent emission spectrum could be one of the most diagnostic techniques for monitoring the solid‐state guest‐exchange process.
Shape, Size, and Phase‐Controlled Rare‐Earth Fluoride Nanocrystals with Optical Up‐Conversion Properties
Authors: Zhang Fan , Li Jing , Shan Jiong , Xu Lei , Zhao Dongyuan
Published: September 2009

High‐quality rare‐earth fluorides, α‐NaMF4 (M=Dy, Ho, Er, Tm, Y, Yb, and Lu) nanocrystals and β‐NaMF4 (M=Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Y, Yb, and Lu) nanoarrays, have been synthesized by using oleic acid as a stabilizing agent through a facile hydrothermal method at 130–230 °C. The phase, shape, and size of the products are varied by careful control of synthetic conditions, including hydrothermal temperature and time, and the amounts of reactants and solvents. Tuning the hydrothermal temperature, time, and the amount of NaOH can cause the transformation from the cubic α‐NaMF4 to hexagonal phase β‐NaMF4. Upon adjustment of the amount of NaOH, NaF, M3+, and ethanol, the morphologies for the β‐NaMF4 nanoarrays can range from tube, rod, wire, and zigzagged rod, to flower‐patterned disk. Simultaneously, the size of the rare‐earth fluoride crystals is variable from 5 nm to several micrometers. A combination of “diffusion‐controlled growth” and the “organic–inorganic interface effect” is proposed to understand the formation of the nanocrystals. An ideal “1D growth” of rare‐earth fluorides is preferred at high temperatures and high ethanol contents, from which the tube‐ and rodlike nanoarrays with high aspect ratio are obtained. In contrast, the disklike β‐NaMF4 nanoarrays with low aspect ratios are produced by decreasing the ethanol content or prolonging the reaction time, an effect probably caused by “1D/2D ripening”. Multicolor up‐conversion fluorescence is also successfully realized in the Yb3+/Er3+ (green, red) and Yb3+/Tm3+ (blue) co‐doped α‐NaYF4 nanocrystals and β‐NaYF4 nanoarrays by excitation in the NIR region (980 nm).
Vicinal Dinitridoruthenium‐Substituted Polyoxometalates γ‐[XW10O38{RuN}2]6− (X=Si or Ge)
Authors: Besson Claire , Musaev Djamaladdin G. , Lahootun Vanina , Cao Rui , Chamoreau Lise‐Marie , Villanneau Richard , Villain Françoise , Thouvenot René , Geletii Yurii V. , Hill Craig L. , Proust Anna
Published: September 2009

Reaction of the divacant polyoxometalate K8[γ‐XW10O36] (X=Si, Ge) with two equivalents of the metal‐nitrido precursor Cs2[RuVINCl5], at room temperature in water, produces K2(Me2NH2)2H2[γ‐XW10O38{RuN}2], X=Si (DMA‐1 a) or Ge (DMA‐1 b). The X‐ray crystal structures of both complexes show monomeric complexes with highly unusual vicinal terminal metal‐nitrido units. The RuN bond lengths are 1.594(10) and 1.612(11) Å in 1 a and 1 b, respectively. EXAFS studies confirmed the key structural assignments from X‐ray crystallography. The XANES spectrum of DMA‐1 a, diamagnetism, NMR (29Si and 183W) chemical shifts, voltammetric behavior, reductive titrations with [PW12O40]4−, and computational data are all consistent with d2 RuVI centers in these complexes. The FT‐IR and Raman spectra show the expected vibrational modes of the {γ‐XW10} unit and the RuN stretch at 1080 cm−1, respectively. Interestingly, reduction of DMA‐1 a by 4 equivalents of [PW12O40]4− produces NH3 in nearly quantitative yield. Cyclic voltammetry versus pH and calculations provide the energetics for the possible two‐electron reduction and two‐proton addition processes in this reaction.
Facile Synthesis of Nitrogen Tetradentate Ligands and Their Applications in CuI‐Catalyzed N‐Arylation and Azide–Alkyne Cycloaddition
Authors: Li Fuwei , Hor T. S. Andy
Published: September 2009

Five new tetradentate ligands [NNNN] with benzimidazolyl‐imine or amine nitrogen donors have been synthesized in good yields under mild conditions from easily available substrates. trans‐N,N′‐bis(1‐Ethyl‐2‐benzimidazolylmethylene)cyclohexane‐1,2‐diimine is the best accelerating ligand in this series that supports the CuI‐catalyzed Ullmann N‐arylation and the direct three‐component azide–alkyne cycloaddition reaction to give the corresponding substituted imidazole, pyrazole, and triazole in high yields. Single‐crystal X‐ray diffraction analysis of its complex with CuI reveals a novel one‐dimensional coordination polymer of the metal chain bridged alternately by the [NNNN] ligand and diiodides.
From Racemic Compound to Spontaneous Resolution: A Linker‐Imposed Evolution of Chiral [MnMo9O32]6−‐Based Polyoxometalate Compounds
Authors: Tan Huaqiao , Li Yangguang , Chen Weilin , Liu Ding , Su Zhongmin , Lu Ying , Wang Enbo
Published: September 2009

Five compounds based on [MnMo9O32]6−: (Himi)6[MnMo9O32] (1) (imi=imidazole), Na2(Himi)4[MnMo9O32]⋅2 H2O (2), Na3(Himi)3[MnMo9O32] (3), D‐NH4Mn2.5[MnMo9O32]⋅11 H2O (4 a), and L‐NH4Mn2.5[MnMo9O32]⋅11 H2O (4 b) were prepared and characterized. X‐ray crystallographic analysis revealed that compounds 1 and 2 with imidazole molecules as linkers are racemic compounds; compound 3 is a racemic solid solution of Na+ cations and the polyoxoanion [MnMo9O32]6−; and compounds 4 a and 4 b are enantiomers. In compound 4, the homochiral polyoxoanions [MnMo9O32]6− are connected by Mn2+ cations to form a unique (45⋅6)(47⋅68) topology net framework. By adjusting the linkers from imidazole molecules to Na+ and finally Mn2+ cations, the chiral polyoxoanions [MnMo9O32]6− were changed from a racemic compound to a conglomerate. This means that spontaneous resolution can be efficiently realized by connecting homochiral polyoxoanions into one‐dimensional (1D), 2D, and 3D structures, with an emphasis on using appropriate linkers with substantial interaction strength, directionality, and enantioselectivity.
Mechanism of Electrocyclic Ring‐Opening of Diphenyloxirane: 40 Years after Woodward and Hoffmann
Authors: Friedrichs Jana , Frank Irmgard
Published: September 2009

The photochemistry of diphenyloxirane has been investigated by using static density functional theory and first‐principles molecular dynamics. We optimised potential‐energy surfaces for both the disrotatory and the conrotatory pathway in the first excited state. Although the disrotatory pathway does not seem to be favoured energetically, we get only the disrotatory product during the molecular dynamics simulations. This can be attributed to the “on‐the‐fly” description of the electronic structure in a first‐principles molecular dynamics simulation. The different photochemical behaviour of aryl oxiranes and unsubstituted oxirane is due to different shapes of the frontier orbitals.
Palladium(II) Complexes of New Bulky Bidentate Phosphanes: Active and Highly Regioselective Catalysts for the Hydroxycarbonylation of Styrene
Authors: Frew Jamie J. R. , Damian Karen , Van Rensburg Hendrik , Slawin Alexandra M. Z. , Tooze Robert. P. , Clarke Matthew L.
Published: September 2009

The synthesis of four new bulky bidentate phosphines that possess both tert‐butyl and trifluoromethylphenyl substituents is described. Symmetric ligands were readily obtained by alkylation of phosphidoboranes of the type Li[P(BH3)(tBu)(Ar)] with dihaloalkanes. Non‐symmetric ligands were prepared from a new stable precursor, tBu2P(BH3)(CH2)3Br, that should prove useful for other ligand syntheses. Palladium(II) complexes of the four new ligands were prepared and were characterised by spectroscopic methods, microanalysis and X‐ray crystallography. The new [PdCl2(L)] complexes were evaluated as catalysts for the hydroxycarbonylation of styrene and found to give unprecedented regioselectivity and yields for a diphosphine‐based catalyst. A study on promoter effects reveals that the presence of acid and chloride is necessary to achieve such selectivities. It has been proposed in the literature that such conditions result in a new pathway in which styrene is converted into 2‐phenethyl chloride, with the latter being the real substrate in the reaction. However, a deuterium labelling study seems to rule out this mechanism, at least under the conditions used herein.
Germa‐closo‐dodecaborate: A New Ligand in Transition‐Metal Chemistry with a Strong trans Influence
Authors: Dimmer Jörg‐Alexander , Schubert Hartmut , Wesemann Lars
Published: September 2009

The strong nucleophilic character of germa‐closo‐dodecaborate towards late transition metal centres is described. The synthesis and characterisation of the first germa‐closo‐dodecaborate complexes are presented, and the solid state structures of the germaborate transition metal complexes were determined by X‐ray crystal structure analyses. The strong trans influence of the new germaborate ligand was determined by IR spectroscopy and NMR coupling constants.
Isolation and Structural X‐ray Investigation of Perfluoroalkyl Derivatives of Six Cage Isomers of C84
Authors: Tamm Nadezhda B. , Sidorov Lev N. , Kemnitz Erhard , Troyanov Sergey I.
Published: September 2009

Perfluoroalkylation of a higher fullerene mixture with CF3I or C2F5I, followed by HPLC separation of CF3 and C2F5 derivatives, resulted in the isolation of several C84(RF)n (n=12, 16) compounds. Single‐crystal X‐ray crystallography with the use of synchrotron radiation allowed structure elucidation of eight C84(RF)n compounds containing six different C84 cages (the number of the C84 isomer is given in parentheses): C84 (23)(C2F5)12 (I), C84 (22)(CF3)16 (II), C84 (22)(C2F5)12 (III), C84 (11)(C2F5)12 (IV), C84 (16)(C2F5)12 (V), C84 (4)(CF3)12 (VI with toluene and VII with hexane as solvate molecules), and C84 (18)(C2F5)12 (VIII). Whereas some connectivity patterns of C84 isomers (22, 23, 11) had previously been unambiguously confirmed by different methods, derivatives of C84 isomers numbers 4, 16, and 18 have been investigated crystallographically for the first time, thus providing direct proof of the connectivity patterns of rare C84 isomers. General aspects of the addition of RF groups to C84 cages are discussed in terms of the preferred positions in the pentagons under the formation of chains, pairs, and isolated RF groups.
Highly Enantioselective Conjugate Additions of Phosphites to α,β‐Unsaturated N‐Acylpyrroles and Imines: A Practical Approach to Enantiomerically Enriched Amino Phosphonates
Authors: Zhao Depeng , Wang Yuan , Mao Lijuan , Wang Rui
Published: September 2009

The first highly enantioselective phosphonylation of α,β‐unsaturated N‐acylpyrroles has been developed. Excellent yields (91–99 %) and enantioselectivities (up to >99 % enantiomeric excess (ee)) were observed for a broad spectrum of both phosphites and N‐acylpyrroles under mild conditions. In particular, when diethyl phosphite was employed to test the scope of the N‐acylpyrroles, almost optically pure products (98 to >99 % ee) were obtained for 20 examples of N‐acylpyrroles. Moreover, optically pure α‐substituted β‐ or γ‐amino phosphonates can be obtained by several simple transformations of the pyrrolyl phosphonates. The versatility of the N‐acylpyrrole moiety makes the phosphorus adducts powerful chiral building blocks that enable the synthesis of various phosphonate‐containing compounds. Finally, the present strategy can also be applied to the asymmetric hydrophosphonylation of N‐acylimines with high enantioselectivities (93 to >99 % ee).
Fraktionierung pflanzlicher Rohstoffe zur simultanen Erzeugung von Lebensmitteln, technischen Rohstoffen und Energieträgern
Authors: Menner M. , Müller K. , Pickardt C. , Eisner P.
Published: September 2009

In Zeiten von Ressourcenknappheit und einer stetig anwachsenden Belastung der Atmosphäre mit Kohlendioxid ist die Nutzung pflanzlicher Rohstoffe ein wichtiger Lösungsansatz. Die Lebensmittelverfahrenstechnik eröffnet mit maßgeschneiderten Fraktionierungsverfahren für pflanzliches Rohmaterial ein großes Potenzial zur Gewinnung wertvoller Inhaltsstofffraktionen, die zur Energiegewinnung, im Lebens‐ und Futtermittelbereich und als technische Rohstoffe in der chemischen und pharmazeutischen Industrie eingesetzt werden können. Der Beitrag gibt einen Überblick über Produktion und Einsatz pflanzlicher Rohstoffe in Deutschland und zeigt am Beispiel der Ölsamen detailliert Fraktionierungsverfahren und ‐strategien auf. Neben der Beschreibung von Verfahren zur Gewinnung von Öl, Proteinen, Kohlenhydraten und Polyphenolen werden Beispiele für deren Anwendung gegeben.
The Emerging Therapeutic Potential of Histone Methyltransferase and Demethylase Inhibitors
Authors: Spannhoff Astrid , Hauser Alexander‐Thomas , Heinke Ralf , Sippl Wolfgang , Jung Manfred
Published: September 2009

Epigenetics is defined as heritable changes to the transcriptome that are independent of changes in the genome. The biochemical modifications that govern epigenetics are DNA methylation and posttranslational histone modifications. Among the histone modifications, acetylation and deacetylation are well characterized, whereas the fields of histone methylation and especially demethylation are still in their infancy. This is particularly true with regard to drug discovery. There is strong evidence that these modifications play an important role in the maintenance of transcription as well as in the development of certain diseases. This article gives an overview of the mechanisms of action of histone methyltransferases and demethylases, their role in the formation of certain diseases, and available inhibitors. Special emphasis is placed on the strategies that led to the first inhibitors which are currently available and the screening approaches that were used in that process.
Homoharringtonine, omacetaxine mepesuccinate, and chronic myeloid leukemia circa 2009
Authors: Quintás‐Cardama Alfonso , Kantarjian Hagop , Cortes Jorge
Published: September 2009

Homoharringtonine (HHT) is a natural alkaloid that is obtained from various Cephalotaxus species. The mechanism of action by which HHT exerts its antitumor activity is through inhibition of protein synthesis and promotion of apoptosis. In the 1990s, HHT proved to be significantly active as salvage therapy for patients with chronic myeloid leukemia (CML) after failure on interferon‒α therapy. However, the remarkable success of imatinib mesylate in the treatment of CML relegated HHT to oblivion. The development of omacetaxine mepesuccinate, a subcutaneously bioavailable semisynthetic form of HHT, and its activity in imatinib‐resistant CML has established this agent for the second time as a valuable option in the management of this disease. Preliminary results appear to support the use of this agent for patients who have imatinib‐resistant CML, including those who carry the tyrosine kinase inhibitor‐insensitive mutation that exchanges the amino acids threonine and isoleucine at position 315 (the T315I mutation). In this article, the authors discuss the current data on omacetaxine and the prospects of this agent to be integrated into the state‐of‐the‐art treatment algorithms for CML. Cancer 2009. © 2009 American Cancer Society.
Modified core wash cytology procedure for the immediate diagnosis of core needle biopsies of breast lesions
Authors: Wauters C. A. P. , Sanders‐Eras C. T. , Kooistra B. W. , Strobbe L. J. A.
Published: September 2009

BACKGROUND:

Core wash or touch imprint cytology is often used to obtain a quick, preliminary diagnosis on a core needle biopsy (CNB) of breast lesions, essential for the management of the 1‐day breast clinic. Contradictory results of both techniques in the literature led to this preclinical study investigating an alternative method of touch imprint and core wash cytology.

METHODS:

Thirty breast lesions were biopsied by a core needle in a laboratory setting. The CNBs were collected in RPMI fluid (Roswell Park Memorial Institute fluid). The touch imprint cytology was performed taking the biopsy out of the fluid and smearing it on a microscopic slide and May‐Grunwald Giemsa stained. The core wash cytology was made by fixating the remaining cells in Fixcyt and prepared with a liquid‐based preparation method and Papanicolaou stained. The cytologic findings were categorized into benign, atypical favoring benign, atypical, suspicious, and malignant and compared with the histologic CNB results.

RESULTS:

The CNBs showed 20 of 30 samples to be malignant, 2 to be phylloides tumors, 7 to be benign, and 1 to be unsatisfactory. Both techniques showed a sensitivity of 95% and specificity of 100%. Touch imprint yielded insufficient diagnoses (13.3%), compared with core wash (6.6%). Of the core wash cases, 86% showed a good quality versus 30% in touch imprint cytology.

CONCLUSIONS:

This preclinical study on modified touch imprint and core wash techniques led to results that were comparable to or better than those in the literature. The core wash cytology is preferred to touch imprint because of the better morphology. Cancer (Cancer Cytopathol) 2009. © 2009 American Cancer Society.
Performance‐based scheduling strategies for HTC applications in complex federated grids
Authors: Leal Katia , Huedo Eduardo , Llorente Ignacio M.
Published: September 2009

The main purpose of the present study is to analyze the suitability of performance‐based scheduling strategies for High Throughput Computing applications applied to Federated Grids consisting of several Grid infrastructures. The infrastructures forming aFederated Grid are classified as internal or external. This is because our scheduling policies map as much jobs as possible first to internal resources. In this way the mapping strategies save time and communication bandwidth by exploiting the location of the internal resources and the membership to their respective resource domains. At the same time, the policies avoid overloading external resources facilitating the cooperation between organizations to share resources. In this paper we consider three new algorithms for scheduling in situations where there are several Grid infrastructures of different types: enterprise, partner, or utility. Copyright © 2009 John Wiley & Sons, Ltd.
An optimized flow cytometry protocol for analysis of angiogenic monocytes and endothelial progenitor cells in peripheral blood
Authors: Hristov Mihail , Schmitz Susanne , Schuhmann Christoph , Leyendecker Thorsten , von Hundelshausen Philipp , Krötz Florian , Sohn Hae‐Young , Nauwelaers Frans A. , Weber Christian
Published: September 2009

Circulating adult CD34+VEGFR2+ endothelial progenitor cells (EPCs) have been shown to differentiate into endothelial cells, thus contributing to vascular homeostasis. Furthermore, a subset of circulating CD14+ monocytes coexpresses CD16 together with the angiopoietin receptor Tie2 and has been functionally implicated in tumor angiogenesis. However, clinically applicable protocols for flow cytometric quantification of EPCs and Tie2+ monocytes in peripheral blood and a consensus on reference values remain elusive. The number of Tie2+CD14+CD16mid angiogenic monocytes and CD34+VEGFR2+CD45low/− EPCs was assessed in the peripheral venous blood of patients with stable coronary artery disease by three‐color flow cytometry using specific monoclonal antibodies conjugated to PerCP, PE, PE‐Cy7, APC, and APC‐Cy7. Scatter multigating with exclusion of dead cells was performed to dissect complex mononuclear cell populations. This analysis was further refined by matching bright fluorochromes (PE‐Cy7, PE, APC) with dimly expressed markers (CD34, VEGFR2, Tie2), by automatic compensation for minimizing fluorescence spillover and by using fluorescence‐minus‐one (FMO) controls to determine positive/negative boundaries. Presuming a Gaussian distribution, we obtained average values (mean ± SD) of 1.45 ± 1.29% for Tie2+CD14+CD16mid monocytes (n = 11, range: 0.12–3.64%) and 0.019 ± 0.013% for CD34+VEGFR2+CD45low/− EPCs (n = 17, range: 0.003–0.042%). The intra‐ and inter‐assay variability was 1.6% and 4.5%, respectively. We have optimized a fast and sensitive assay for the flow cytometric quantification of circulating angiogenic monocytes and EPCs in cardiovascular medicine. This protocol may represent a basis for standardized analysis and monitoring of these cell subsets to define their normal range and prognostic/diagnostic value in clinical use. © 2009 International Society for Advancement of Cytometry
Umwelt‐Produktdeklarationen als Datenbasis für die Nachhaltigkeits‐Bewertung – Mauerwerk für nachhaltige Gebäude
Authors: Bossenmayer Horst , Peters Hans R.
Published: September 2009

Zu den dauerhaftesten Bauwerken der Menschheit gehören Mauerwerksbauten wie die Pyramiden von Gizeh, die Chinesische Mauer oder die zahlreichen Repräsentanten gesellschaftlicher Strukturen wie der Kreml, das Weiße Haus oder der Reichstag in Berlin.

Bei der aktuellen Herausforderung des Nachhaltigen Bauens geht es aber um mehr: die Qualität und Zukunftsfähigkeit von Gebäuden für die gesamte Breite baulicher Aufgaben. Diese hängen wesentlich von den verwendeten Bauprodukten, deren Einbausituation und Leistungsfähigkeit ab. Die entsprechende Information über Baustoffe und Bauteile ist somit ein grundsätzliches Element des Nachhaltigen Bauens. Umwelt‐Produktdeklarationen (Environmental Product‐Declarations, EPDs) vermitteln neutrale und umfassende Daten über die Umweltleistung von Bauprodukten und machen zugleich Aussagen über deren funktionale Qualität.
Experimentelle und theoretische Untersuchungen zum Verbund von auf Mauerwerk aufgeklebten faserverstärkten Kunststoffen
Authors: Pfeiffer Uwe , Seim Werner
Published: September 2009

Faserverstärkte Kunststoffe gewinnen im Bereich der Verstärkung und der Sanierung von Bauwerken zunehmend an Bedeutung. Für die nachträgliche Biege‐ und Schubverstärkung von Betonbauteilen hat sich ihre Anwendung bewährt und ist aus der heutigen Baupraxis nicht mehr wegzudenken. Faserverstärkte Kunststoffe – auch als Faserverbundwerkstoffe (FVW) bezeichnet – können überall dort sinnvoll angewendet werden, wo es infolge einer Überlastung zu einem Zugversagen kommt. Diesem können FVW wie eine Art Zugbewehrung entgegenwirken. Die vergleichsweise hohe Zugfestigkeit bei geringen Querschnitten sowie Flächengewichten zeichnet FVW aus. Zudem lassen sie sich schnell und einfach auf Bauteilstrukturen aufkleben. Somit kann mit FVW gezielt, effektiv und substanzschonend in das Tragverhalten eingegriffen werden. Eine wesentliche Voraussetzung hierfür ist die Kenntnis über die Verbundcharakteristik zwischen FVW und Mauerwerk. Im vorliegenden Aufsatz werden hierzu grundlegende experimentelle und theoretische Ergebnisse eines Forschungsprojektes zu auf Mauerwerk aufgeklebten FVW dokumentiert und erläutert.
Umweltverträglichkeit von mineralischen Baustoffen
Authors: Brameshuber Wolfgang , Vollpracht Anya
Published: September 2009

In diesem Beitrag wird der Stand der Forschung zur Bewertung des Auslaugverhaltens mineralischer Baustoffe während der Nutzungsphase zusammengefasst. Für den Einbau von Beton im Grundwasser wurde ein Bewertungskonzept erarbeitet, mit dem die Grundwasserverträglichkeit anhand eines relativ einfachen Auslaugversuchs beurteilt werden kann. Für Mauerwerksbaustoffe ist das Bewertungskonzept in dieser Form nicht geeignet, da diese Baustoffe nicht in direktem Kontakt mit dem Grundwasser eingebaut werden. Eine Auslaugung kann hier bei Beregnung auftreten. Für dieses Szenario liegt noch kein Bewertungskonzept vor, es wurden jedoch erste Versuche an Mauersteinen, Putzen und Dacheindeckungen durchgeführt, die kurz vorgestellt werden. Da Beregnungsversuche sehr aufwendig sind, wäre es günstig, wenn die Bewertung anhand eines einfacheren Langzeitstandtests erfolgen könnte. Dies wurde im Rahmen der Untersuchungen überprüft. In aller Regel liegt die Freisetzung im Beregnungsversuch unter der Freisetzung bei durchgehender Wasserbeaufschlagung. Das bedeutet, das Beregnungsszenario kann über eine Prüfung mit dem Langzeitstandtest abgedeckt werden, es sind keine weiteren Prüfungen nötig.
Heart rate variability in response to pain stimulus in VLBW infants followed longitudinally during NICU stay
Authors: Padhye Nikhil S. , Williams Amber L. , Khattak Asif Z. , Lasky Robert E.
Published: September 2009

The objective of this longitudinal study, conducted in a neonatal intensive care unit, was to characterize the response to pain of high‐risk very low birth weight infants (<1,500 g) from 23 to 38 weeks post‐menstrual age (PMA) by measuring heart rate variability (HRV). Heart period data were recorded before, during, and after a heel lanced or wrist venipunctured blood draw for routine clinical evaluation. Pain response to the blood draw procedure and age‐related changes of HRV in low‐frequency and high‐frequency bands were modeled with linear mixed‐effects models. HRV in both bands decreased during pain, followed by a recovery to near‐baseline levels. Venipuncture and mechanical ventilation were factors that attenuated the HRV response to pain. HRV at the baseline increased with post‐menstrual age but the growth rate of high‐frequency power was reduced in mechanically ventilated infants. There was some evidence that low‐frequency HRV response to pain improved with advancing PMA. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 638–649, 2009
Ontogeny of Rat Recognition Memory measured by the novel object recognition task
Authors: Reger Maxine L. , Hovda David A. , Giza Christopher C.
Published: September 2009

Detection of novelty is an essential component of recognition memory, which develops throughout cerebral maturation. To better understand the developmental aspects of this memory system, the novel object recognition task (NOR) was used with the immature rat and ontogenically profiled. It was hypothesized that object recognition would vary across development and be inferior to adult performance. The NOR design was made age‐appropriate by downsizing the testing objects and arena. Weanling (P20–23), juvenile (P29–40), and adult (P50+) rats were tested after 0.25, 1, 24, and 48 hr delays. Weanlings exhibited novel object recognition at 0.25 and 1 hr, while older animals showed a preference for the novel object out to 24 hr. These findings are consistent with previous research performed in humans and monkeys, as well as to studies using the NOR after medial temporal lobe damage in adult rats. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 672–678, 2009
Synthesis and Characterisation of [XeF5]3[Ti4F19] Containing a Discrete [Ti4F19]3– Anion
Authors: Mazej Zoran , Goreshnik Evgeny
Published: September 2009

The complex [XeF5]3[Ti4F19] was prepared by reaction of XeF2, TiF4 and UV‐irradiated elemental fluorine in anhydrous hydrogen fluoride as the solvent. The crystal structure of [XeF5]3[Ti4F19] consists of [XeF5]+ cations and discrete [Ti4F19]3– anions. The [XeF5] units have usual slightly distorted pseudo‐octahedral symmetry. Contrary to the previously reported [Ti4F18]2– anion, where each TiF6 octahedron shares three apexes with three other octahedra, in [Ti4F19]3–, only two μ3‐[TiF6] octahedra share three apexes with three other [TiF6] units. Each of the remaining two μ2‐[TiF6] octahedra shares only two vertices with two of the above‐mentioned μ3‐[TiF6] moieties. The Raman spectrum of [XeF5]3[Ti4F19] is in agreement with the presence of [XeF5]+ cations and [Ti4F19]3– anions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of New δ‐(Polyfluoroalkyl)‐δ‐hydroxy‐α‐amino Acids
Authors: Tolmacheva Nataliya A. , Gerus Igor I. , Dolovanyuk Violetta G. , Kondratov Ivan S. , Haufe Günter
Published: September 2009

New δ‐(polyfluoroalkyl)‐δ‐hydroxy‐α‐amino acids were synthesized from the corresponding starting 3‐(benzoylamino)‐6‐(polyfluoroalkyl)‐2H‐pyran‐2‐ones. The key step of the synthesis was the hydrogenation of the pyrone ring. Stereoselectivity and yields depended dramatically on the reaction conditions and the nature of the polyfluoroalkyl group. Various conditions were used for the preparation of both mixtures of diastereomers and pure diastereomers of the target amino acids. The obtained δ‐(polyfluoroalkyl)‐δ‐hydroxy‐α‐amino acids are of interest as analogues of 2‐amino‐5‐hydroxyvaleric acid and glutamic acid.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of Novel Ferrocenyl‐Based P,S Ligands (ThioClickFerrophos) and Their Use in Pd‐Catalyzed Asymmetric Allylic Substitutions
Authors: Kato Minoru , Nakamura Tatsuhito , Ogata Kenichi , Fukuzawa Shin‐ichi
Published: September 2009

A series of P,S ligands (ThioClickFerrophos) based on a triazoleferrocenylethyl backbone were synthesized in a four‐step sequence by click chemistry methodology. The new P,S ligands were applied in allylic alkylations, etherifications, and aminations of 1,3‐diphenylprop‐2‐enyl acetate catalyzed by Pd complexes. These reactions proceeded smoothly to give products in good yields and with good enantioselectivities of up to 90 % ee. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Integration of serpentine channels for microchip electrophoresis with a palladium decoupler and electrochemical detection
Authors: Bowen Amanda L. , Scott Martin R.
Published: September 2009

Although it has been shown that microchip electrophoresis (MCE) with electrochemical detection can be used to separate and detect electroactive species, there is a need to increase the separation performance of these devices so that complex mixtures can be routinely analyzed. Previous work in the MCE has demonstrated that increasing the separation channel length leads to an increase in resolution between closely eluting analytes. This paper details the use of lengthened serpentine microchannels for MCE and electrochemical detection where a palladium decoupler is used to ground the separation voltage so that the working electrodes remain in the fluidic network. In this work, palladium electrodepositions were used to increase the decoupler surface area and more efficiently dissipate hydrogen produced at the decoupler. Dopamine and norepinephrine, which only differ in structure by a hydroxyl group, were used as model analytes. It was found that increasing the separation channel length led to improvements in both the resolution and the number of theoretical plates for these analytes. The use of a bilayer valving device, where PDMS‐based valves are utilized for the injection process, along with serpentine microchannels and amperometric detection resulted in a multianalyte separation and an average of 28 700 theoretical plates. It was also shown that the increased channel length is beneficial when separating and detecting analytes from a high ionic strength matrix. This was demonstrated by monitoring the stimulated release of neurotransmitters from a confluent layer of PC 12 cells.
Centrosomes and myeloma; Aneuploidy and proliferation
Authors: Chng Wee J. , Fonseca Rafael
Published: September 2009

Multiple myeloma is the second most common hematological malignancy in the United States. The disease is characterized by an accumulation of clonal plasma cells. Clinically, patients present with anemia, lytic bone lesions, hypercalcaemia, or renal impairment. The genome of the malignant plasma cells is extremely unstable and is typically aneuploid and characterized by a complex combination of structure and numerical abnormalities. The basis of the genomic instability underlying myeloma is unclear. In this regard, centrosome amplification is present in about a third of myeloma and may represent a mechanism leading to genomic instability in myeloma. Centrosome amplification is associated with high‐risk features and poor prognosis. Understanding the underlying etiology of centrosome amplification in myeloma may lead to new therapeutic avenues. Environ. Mol. Mutagen., 2009. © 2009 Wiley‐Liss, Inc.
The reactive Riemann problem for thermally perfect gases at all combustion regimes
Authors: Beccantini A. , Studer E.
Published: September 2009

In this work we analyze the reactive Riemann problem for thermally perfect gases in the deflagration or detonation regimes. We restrict our attention to the case of one irreversible infinitely fast chemical reaction; we also suppose that, in the initial condition, one state (for instance the left one) is burnt and the other one is unburnt. The indeterminacy of the deflagration regime is removed by imposing a (constant) value for the fundamental flame speed of the reactive shock. An iterative algorithm is proposed for the solution of the reactive Riemann problem. Then the reactive Riemann problem and the proposed algorithm are investigated from a numerical point of view in the case in which the unburnt state consists of a stoichiometric mixture of hydrogen and air at almost atmospheric condition. In particular, we revisit the problem of 1D plane‐symmetric steady flames in a semi‐infinite domain and we verify that the transition from one combustion regime to another occurs continuously with respect to the fundamental flame speed and the so‐called piston velocity. Finally, we use the ‘all shock’ solution of the reactive Riemann problem to design an approximate (‘all shock’) Riemann solver. 1D and 2D flows at different combustion regimes are computed, which shows that the approximate Riemann solver, and thus the algorithm we use for the solution of the reactive Riemann problem, is robust in both the deflagration and detonation regimes. Copyright © 2009 John Wiley & Sons, Ltd.
The modeling of realistic chemical vapor infiltration/deposition reactors
Authors: Ibrahim John , Paolucci Samuel
Published: September 2009

We describe the low Mach number equations as well as a second‐order numerical integration procedure that are used to solve a realistic chemical vapor infiltration/chemical vapor deposition (CVI/CVD) problem. The simulation accounts for a homogeneous gas chemical reaction mechanism, a heterogeneous surface reaction mechanism, and an evolving pore structure model. The numerical solution of the model ultimately leads to the solution of a large system of stiff differential algebraic equations that are to be integrated over a long time. An operator splitting algorithm is employed to deal with the stiffness associated with chemical reactions, whereas a projection method is employed to overcome the difficulty arising from having to solve a large coupled system for velocity and pressure fields. Results show that the proposed integration procedure is very efficient for modeling long time CVI/CVD densification processes. Copyright © 2009 John Wiley & Sons, Ltd.
Implicit algebraic model for predicting turbulent heat flux in film cooling flow
Authors: Rajabi‐Zargarabadi Mehran , Bazdidi‐Tehrani Farzad
Published: September 2009

The present study addresses a new effort to improve the prediction of turbulent heat flux in the film cooling flow by applying the implicit algebraic flux (IAF) model of Rogers et al. A three‐dimensional symmetry case is investigated using a film hole length‐to‐diameter ratio of 1.75 and an injection angle of 35∘. The low Reynolds number second moment closure (SMC) model with a wall‐reflection term is employed for simulating the turbulent flow field right up to the wall. Results obtained from the IAF model are compared with two other algebraic turbulent heat flux models, namely, the simple eddy diffusivity (SED) with a constant turbulent Prandtl number and the generalized gradient diffusion hypothesis (GGDH). Comparisons of the turbulent heat flux components calculated by these models show that the major difference appears in the streamwise turbulent heat flux. These models demonstrate a significant effect on the prediction of film cooling effectiveness. The SED model with a constant prescribed value for the turbulent Prandtl number fails to predict the cooling air spreading in the lateral direction while by employing the GGDH and IAF models, the spreading of the cooling air and the decay of the effectiveness in the core region are reasonably predicted. A combination of the SMC and IAF models for simulating the turbulent flow and heat transfer is capable of predicting the streamwise and lateral film cooling effectiveness in very good agreement with the available experimental data. Copyright © 2009 John Wiley & Sons, Ltd.
A hybrid Padé ADI scheme of higher‐order for convection–diffusion problems
Authors: Karaa Samir
Published: September 2009

A high‐order Padé alternating direction implicit (ADI) scheme is proposed for solving unsteady convection–diffusion problems. The scheme employs standard high‐order Padé approximations for spatial first and second derivatives in the convection‐diffusion equation. Linear multistep (LM) methods combined with the approximate factorization introduced by Beam and Warming (J. Comput. Phys. 1976; 22: 87–110) are applied for the time integration. The approximate factorization imposes a second‐order temporal accuracy limitation on the ADI scheme independent of the accuracy of the LM method chosen for the time integration. To achieve a higher‐order temporal accuracy, we introduce a correction term that reduces the splitting error. The resulting scheme is carried out by repeatedly solving a series of pentadiagonal linear systems producing a computationally cost effective solver. The effects of the approximate factorization and the correction term on the stability of the scheme are examined. A modified wave number analysis is performed to examine the dispersive and dissipative properties of the scheme. In contrast to the HOC‐based schemes in which the phase and amplitude characteristics of a solution are altered by the variation of cell Reynolds number, the present scheme retains the characteristics of the modified wave numbers for spatial derivatives regardless of the magnitude of cell Reynolds number. The superiority of the proposed scheme compared with other high‐order ADI schemes for solving unsteady convection‐diffusion problems is discussed. A comparison of different time discretizations based on LM methods is given. Copyright © 2009 John Wiley & Sons, Ltd.
Numerical simulation of gaseous fuel injection: A new methodology for multi‐dimensional modelling
Authors: Andreassi Luca , Facci Andrea Luigi , Ubertini Stefano
Published: September 2009

The use of natural gas (instead of liquid or solid fuels) is nowadays drawing an increasing interest in many applications (gas turbines, boilers, internal combustion engines), because of the greater attention to environmental issues. To facilitate the development of these applications, computer models are being developed to simulate gaseous injection, air entrainment and the ensuing combustion.

This paper introduces a new method for modelling the injection process of gaseous fuels that aims to hold down grid requirements in order to allow the simulation also of other phenomena, like combustion or valve and piston motion, in reciprocating internal combustion engines. After a short overview of existing models, the transient jet model and the evaluation of inflow conditions are described in detail. Then a basic study of the grid effects on the jet evolution is presented. The model is updated and validated by comparing numerical results with available experimental data for two different operating conditions: a subsonic and a supersonic under‐expanded case. The model demonstrates to be fast enough to be used in a multi‐dimensional code and accurate enough to follow the real gas jet evolution. Copyright © 2009 John Wiley & Sons, Ltd.
Effect of heat transfer on the flow of a second‐grade fluid in divergent/convergent channel
Authors: Hayat T. , Nawaz M. , Sajid M.
Published: September 2009

This paper studies the effects of a second‐grade fluid on the flow and heat transfer characteristics in a divergent/convergent channel. The momentum and energy equations are first given in a nondimensional form and then solved analytically using the method of homotopy analysis method. Convergence of derived series solutions is shown. Graphical results for the velocity and the temperatures are presented and discussed for various emerging parameters. Copyright © 2009 John Wiley & Sons, Ltd.
Chronically inflamed livers up-regulate expression of inhibitory B7 family members #
Authors: Kassel Rachel , Cruise Michael W. , Iezzoni Julia C. , Taylor Nicholas A. , Pruett Timothy L. , Hahn Young S.
Published: September 2009

Hepatitis B virus, hepatitis C virus, autoimmune hepatitis, and nonalcoholic fatty liver disease can induce chronic liver disease. The Programmed Death-1 (PD-1) inhibitory pathway assists in T cell response regulation during acute and chronic inflammation and participates in the progression of inflammatory liver disease. To examine whether PD-1 and its ligands, B7-H1 and B7-DC, are modulated during chronic necroinflammatory liver disease, we investigated expression profiles in normal patients and patients with the aforementioned conditions. Relative to liver biopsies from normal individuals, those from patients with chronic necroinflammatory liver diseases (hepatitis B virus, hepatitis C virus, and autoimmune hepatitis) contain increased numbers of PD-1–expressing lymphocytes. Kupffer cells, liver sinusoidal endothelial cells, and leukocytes express PD-1 ligands. We also detect PD-1 ligands on hepatocytes within biopsies and on isolated cells. All forms of chronic necroinflammatory liver disease examined correlate with increased B7-H1 and B7-DC expression on Kupffer cells, liver sinusoidal epithelial cells, and leukocytes. The degree of necroinflammation correlates with expression levels of PD-1 family members. Conclusion: These results demonstrate that expression of PD-1/PD-1 ligands links more directly with the degree of inflammation than with the underlying etiology of liver damage. The PD-1 pathway may assist the liver in protecting itself from immune-mediated destruction. (Hepatology 2009.)
The effect of study arm on prostate cancer treatment in the large screening trial ERSPC
Authors: Wolters Tineke , Roobol Monique J. , Steyerberg Ewout W. , van den Bergh Roderick C.N. , Bangma Chris H. , Hugosson Jonas , Ciatto Stefano , Kwiatkowski Maciej , Villers Arnauld , Luján Marcos , Nelen Vera , Tammela Teuvo L.J. , Schröder Fritz H.
Published: September 2009

Prostate cancer (PC) mortality is the most valid end‐point in screening trials, but could be influenced by the choice of initial treatment if treatment has an effect on mortality. In this study, PC treatment was compared between the screening and control arms in a screening trial. Data were collected from the European Randomized Study of Screening for Prostate Cancer (ERSPC). The characteristics and initial treatment of PC cases detected in the screening and the control arm were compared. Polytomous logistic regression analysis was used to assess the influence of study arm on treatment, adjusting for potential confounders and with statistical imputation of missing values. A total of 8,389 PC cases were detected, 5,422 in the screening arm and 3,145 in the control arm. Polytomous regression showed that trial arm was associated with treatment choice after correction for missing values, especially in men with high‐risk PC. A control subject with high‐risk PC was more likely than a screen subject to receive radiotherapy (OR: 1.43, 95% CI: 1.01–2.05, p = 0.047), expectant management (OR: 2.92, 95% CI: 1.33–6.42, p = 0.007) or hormonal treatment (OR: 1.77, 95% CI: 1.07–2.94, p = 0.026) instead of radical prostatectomy. However, trial arm had only a minor role in treatment choice compared to other variables. In conclusion, a small effect of trial arm on treatment choice was seen, particularly in men with high‐risk PC. Therefore, differences in treatment between arms are unlikely to play a major role in the interpretation of the results of the ERSPC.
CDKN2A but not TP53 mutations nor HPV presence predict poor outcome in metastatic squamous cell carcinoma of the skin
Authors: Küsters‐Vandevelde Heidi V.N. , Van Leeuwen Arjanne , Verdijk Marian A.J. , de Koning Maurits N.C. , Quint Wim G.V. , Melchers Willem J.G. , Ligtenberg Marjolijn J.L. , Blokx Willeke A.M.
Published: September 2009

Genetic alterations in metastatic cutaneous squamous cell carcinoma (CSCC) which might serve as prognostic biomarkers are not well investigated. We investigated the mutation status and protein expression of the CDKN2A (INK4a‐ARF) and TP53 genes in metastatic CSCCs and correlated this with clinicopathological variables, HPV presence, and survival data. Sequence analysis was performed on formalin‐fixed and paraffin‐embedded tissue of 35 metastases and their primary tumors, and was correlated with immunohistochemical stainings for p53, p16 and p14. Beta‐PV and alpha‐PV DNA was detected using PCR‐based assays. Kaplan–Meier and Cox regression methods were used for survival assessment. CDKN2A was mutated in 31% of the metastases and their primary tumors, while the TP53 gene was mutated in 51% of the metastases. P53 protein expression was significantly associated with missense type of mutations (p = 0.002). No persistent HPV types were detected. CDKN2A mutations were significantly associated with disease‐specific death (p = 0.001). A significant difference was observed in disease‐specific survival between patients with or without a CDKN2A mutation (p = 0.010), while this was not the case for TP53. At univariate Cox's regression analysis tumor size (p = 0.010), invasion depth (p = 0.030) and CDKN2A mutations (p = 0.040) were significantly related to shorter disease‐specific survival. At multivariate Cox's regression only tumor size had an adverse effect on survival (p = 0.002). In conclusion, our study indicates that the CDKN2A mutation status might be of prognostic value in metastatic CSCCs. In most cases, CDKN2A and TP53 mutations are early genetic events in CSCC tumorigenesis. The possible role of HPV in metastatic CSCC needs further exploration.