bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and characterization of biologically active new Schiff bases containing 3‐functionalized 1,2,4‐triazoles and their zinc(II) complexes: crystal structure of 4‐bromo‐2‐[(E)‐(1H‐1,2,4‐triazol‐3‐ylimino)‐ methyl]phenol
Authors: Chohan Zahid H. , Hanif M.
Published: September 2011

Biologically active triazole Schiff bases (L1L3) derived from the reaction of 3‐amino‐1,2,4‐triazole with chloro‐, bromo‐ and nitro‐ substituted salicylaldehydes and their Zn(II) complexes (1–3) have been synthesized and characterized by their physical, spectral and analytical data. Triazole Schiff bases potentially act as tridentate ligands and coordinate with the Zn(II) metal atom through salicylidene‐O, azomethine‐N and triazole‐N. The complexes have the general formula [M(L‐H)2], where M = zinc(II) and L = (L1–L3), and observe an octahedral geometry. The Schiff bases and their Zn(II) complexes have been screened for in‐vitro antibacterial, antifungal and brine shrimp bioassay. The biological activity data show the Zn(II) complexes to be more potent antibacterial and antifungal than the parent simple Schiff bases. Copyright © 2011 John Wiley & Sons, Ltd.
The synthesis, crystal structures and antimicrobial studies of C‐methyl‐substituted hexaaza macrocycle of Cu(II) having aromatic pendant arm
Authors: Husain Ahmad , Nami Shahab A. A. , Siddiqi K. S.
Published: September 2011

Cu(II) complexes of 14‐membered hexaaza macrocyclic ligand with C‐methyl substituent of the type [CuL](X)2 (where L = 3,10‐bisbenzyl‐6,13‐dimethyl‐1,3,5,8,10,12‐hexaazacyclotetradecane, and X = ClO4−, PF6−) were synthesized by tandem reaction. They were characterized by spectral and single‐crystal X‐ray diffraction techniques. The complexes show distorted octahedral geometry and the counter ions are weakly coordinated to the metal ion at the axial positions. The macrocyclic ring adopts the trans‐III configuration with six‐ and five‐membered chelate rings in chair and gauche conformation, respectively. It was observed that in the solid state the arrangement of the coordination sphere is distorted octahedral whereas, in solution, a square‐planar structure is predominant. The molar conductance of the complexes indicates that the axially bonded anions are almost dissociated in acetonitrile solution. The Electron Paramagnetic Resonance (EPR) spectrum of complex 1 is axial and consistent with a dx2 − y2 ground state. The [CuL](ClO4)2 was found to be active against the tested microorganism. Copyright © 2011 John Wiley & Sons, Ltd.
Computational approach on architecture and tailoring of organic metal complexes derived from streptomycin and Zn, Cd and Pb: antimicrobial effectiveness
Authors: Rajiv Kumar , Rajni Johar
Published: September 2011

Streptomycin has been used to derive organic metal complexes (OMCs) after metallation with ZnCl2, CdCl2 and PbCl2 and characterized by elemental analysis, electronic and vibrational spectroscopy, 1H and 13C NMR, mass spectroscopy (time‐of‐flight MS), magnetic measurement, thermal decomposition analysis (TGA, DTA), molecular modeling and X‐ray powder diffraction. OMCs are monomeric. Crystal system, lattice parameters, unit cell, particle size and volume of crystalline OMCs have been determined using X‐ray powder diffraction pattern analysis. The geometries of complexes were optimized on the basis of molecular modeling. Kinetic parameters were computed from thermal analysis, confirming first‐order kinetics. Molecular models have been optimized by MM2 calculations. Architecture and tailoring of the rationally designed and synthesized supramolecular models having covalent bonded oxygen or other molecular contacts extended through Huckel Charge Distribution in highest occupied molecular orbit (HOMO). Antimicrobial effectiveness of OMCs has been reported. Copyright © 2011 John Wiley & Sons, Ltd.
Evolution of the chemical and morphological changes of HDPE when subjected to digestion in a strong acid medium
Authors: Avalos‐Belmontes F. , Ortiz‐Cisneros J.C. , Zapata‐Gonzalez I. , Sánchez‐Valdes S. , Ramos‐deValle L. F.
Published: September 2011

High‐density polyethylene (HDPE) is the polymer most used for geomembranes, and one of the tests to determine its applicability is its long term resistance to oxidation. In this sense, this work focuses on the study of the chemical and morphological changes that PE films may experiment when subjected to digestion in nitric acid, simulating the severe ambient conditions of a landfill. The effect of digestion of HDPE, on its chemical and morphological structure, was evaluated. It was observed that the molecular weight of HDPE decreases, forming acid and nitro groups, as the time of digestion increases. Also, the oxidative degradation first produced a bimodal MW distribution, but as the time of strong acid treatment increases, a trimodal MW distribution appears, at lower molecular weights. Finally, as time of digestion continued, a bimodal MW distribution appears again, but at much lower molecular weights. The crystal size of the treated HDPE is directly related to the HDPE molecular weight, that is, as time of digestion increases, the molecular weight decreases and the crystal size decreases. In addition, the heterogeneity of molecular weights, such as bimodal and trimodal distributions, and the presence of chemical groups other than the normal CH2 strings of pure PE produced defects in the unit cell parameters a and b. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Rheological characteristics and morphologies of styrene–butadiene–maleic anhydride block copolymers
Authors: Wang Wanjie , Li Chunhui , Cao Yanxia , Chen Jinzhou , Wang Jingwu
Published: September 2011

Studies on the morphologies and rheological characteristics of two styrene–butadiene–maleic anhydride block copolymers (SBMa) have been performed. The transmission electron microscopy micrographs show that the morphologies of SBMa change from matrix–island structure to co‐continuous structure. Curves for dynamic modulus varied with frequency (ω) show obvious solid‐like behavior in the low ω region, which is typical for ordered block copolymers or networked materials. Van Gurp–Palmen plots have been used to exploit the thermorheological complexity of two copolymers. The master curves of two copolymers have been acquired through time–temperature superposition principle, and the plateau modulus (G) have been obtained from G′ at ω, where the loss tangent (tan δ) approaches a minimum. Meanwhile, Williams–Landel–Ferry equation has been used to evaluate the free volume parameters. The relaxation time spectra of two copolymers have been calculated and fitted with modified Baumgaertel–Schausberger–Winter model. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Preparation and characterization of silica/polypyrrole core‐shell colloidal particles in the presence of ethanol as the cosolvent
Authors: Sun Libo , Shi Yuanchang , Chu Linya , Wang Ying , Zhang Liyong , Liu Jiurong
Published: September 2011

The silica/polypyrrole core‐shell composites were fabricated by in situ chemical polymerization of pyrrole monomer on the surface of the silica spheres. Silica sol particles with narrow size distributions were prepared by hydrolysis of tetraethoxysilane with sol–gel method. Polypyrrole shell was obtained by chemical polymerization of pyrrole monomer on the surface of the silica spheres in the water–ethanol mixture. It can be seen from the experiment, with the adding of small amount of ethanol cosolvent to the aqueous reaction solution, a uniform coating of polypyrrole appeared on the surface of silica. The core‐shell morphology of composite particles prepared with variation ethanol adding amount was analyzed by TEM. Meanwhile, the conductivity of the core‐shell composite is found to be enhanced apparently compared with those prepared from pure aqueous system. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Influence of acetated‐based and bromo‐based ionic liquids treatment on wool dyeing with acid blue 7
Authors: Wang Nanfang , Jian Yulin , Liu Suqin , Liu Younian , Huang Kelong
Published: September 2011

Bromo‐based and acetated‐based ionic liquids (ILs), 1‐butyle‐3‐methylimidazolium bromo ([Bmim]Br), 1‐ethyl‐3‐mthylimidazolium bromo ([Emim]Br), 1‐butyle‐3‐methylimidazolium acetate ([Bmim]Ac), and 1‐ethyl‐3‐mthylimidazolium acetate ([Emim]Ac), were synthesized and employed for wool surface treatment. Scanning electron microscope results indicated that the wool surfaces treated with acetated‐based ILs were eroded more than those treated with bromo‐based ILs. Comparable studies showed that the wool samples treated with acetate‐based ILs, especially [Emim]Ac, had higher initial dyeing rate and equilibrium exhaustion than those with bromo‐based ILs. Along with treatment temperature and time increasing, acetate‐based ILs had more remarkable effects on mechanical and dyeing properties of the wool samples than bromo‐based ILs. The wool samples treated with [Emim]Ac at 60°C for 10 min had excellent low‐temperature dyeing properties. The color depth (K/S) investigations showed that the wool samples treated with acetate‐based ILs possessed darker color depth than those treated with the bromo‐based ILs. Color fastnesses of the wool samples treated with [Bmim]Br, [Emim]Br and [Bmim]Ac exhibited the same grades as the untreated sample, while wet color fastnesses of [Emim]Ac treated sample were slightly decreased. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and properties of a new red luminescence europium complex containing a 2‐(benzimidazol‐2‐yl)‐8‐octyloxyquinoline as the second ligand
Authors: Li Shanji
Published: September 2011

A new Eu(III) complex, Eu(III)(DBM)3BIOQ, has been synthesized with dibenzoylmethane (DBM) as the first ligand and 2‐(benzimidazol‐2‐yl)‐8‐octyloxyquinoline (BIOQ) as the second ligand. The stability of the complex was analysed by DSC–TG. The results show that the Eu(III) complex has a relatively high thermal stability with a melting point of 235 °C and a decomposition temperature (onset) of 252 °C. The fluorescence properties of the compound were also investigated. The fluorescence results reveal that the as‐prepared complex shows the characteristic maximum emission spectra of Eu(III) at 611 nm (λex = 350 nm). In addition, the photoluminescence spectrum of the complex in the solid state exhibits a single and symmetrical emission band at 611 nm, with a full width at half‐maximum of 4.7 nm, showing high colour purity. This finding indicates the possibility for the development of brighter red luminescent materials. Copyright © 2011 John Wiley & Sons, Ltd.
The “Missing Link”: The Gas‐Phase Generation of Platinum–Methylidyne Clusters PtnCH+ (n=1, 2) and Their Reactions with Hydrocarbons and Ammonia
Authors: Butschke Burkhard , Schwarz Helmut
Published: September 2011

Electrospray ionization (ESI) of tetrameric platinum(II) acetate, [Pt4(CH3COO)8], in methanol generates the formal platinum(III) dimeric cation [Pt2(CH3COO)3(CH2COO)(MeOH)2]+, which, upon harsher ionization conditions, sequentially loses the two methanol ligands, CO2, and CH2COO to form the platinum(II) dimer [Pt2(CH3COO)2(CH3)]+. Next, intramolecular sequential double hydrogen‐atom transfer from the methyl group concomitant with the elimination of two acetic acid molecules produces Pt2CH+ from which, upon even harsher conditions, PtCH+ is eventually generated. This degradation sequence is supported by collision‐induced dissociation (CID) experiments, extensive isotope‐labeling studies, and DFT calculations. Both PtCH+ and Pt2CH+ react under thermal conditions with the hydrocarbons C2Hn (n=2, 4, 6) and C3Hn (n=6, 8). While, in ion–molecule reactions of PtCH+ with C2 hydrocarbons, the relative rates decrease with increasing n, the opposite trend holds true for Pt2CH+. The Pt2CH+ cluster only sluggishly reacts with C2H2, but with C2H4 and C2H6 dihydrogen loss dominates. The reactions with the latter two substrates were preceded by a complete exchange of all of the hydrogen atoms present in the adduct complex. The PtCH+ ion is much less selective. In the reactions with C2H2 and C2H4, elimination of H2 occurs; however, CH4 formation prevails in the decomposition of the adduct complex that is formed with C2H6. In the reaction with C2H2, in addition to H2 loss, C3H3+ is produced, and this process formally corresponds to the transfer of the cationic methylidyne unit CH+ to C2H2, accompanied by the release of neutral Pt. In the ion–molecule reactions with the C3 hydrocarbons C3H6 and C3H8, dihydrogen loss occurs with high selectivity for Pt2CH+, but in the reactions of these substrates with PtCH+ several reaction routes compete. Finally, in the ion–molecule reactions with ammonia, both platinum complexes give rise to proton transfer to produce NH4+; however, only the encounter complex generated with PtCH+ undergoes efficient dehydrogenation of the substrate, and the rather minor formation of CNH4+ indicates that CN bond coupling is inefficient.
Electrical and mechanical anharmonicities from NIR‐VCD spectra of compounds exhibiting axial and planar chirality: The cases of (S)‐2,3‐pentadiene and methyl‐d3 (R)‐ and (S)‐[2.2]paracyclophane‐4‐carboxylate
Authors: Abbate Sergio , Longhi Giovanna , Gangemi Fabrizio , Gangemi Roberto , Superchi Stefano , Caporusso Anna Maria , Ruzziconi Renzo
Published: September 2011

The IR and Near infrared (NIR) vibrational circular dichroism (VCD) spectra of molecules endowed with noncentral chirality have been investigated. Data for fundamental, first, and second overtone regions of (S)‐2,3‐pentadiene, exhibiting axial chirality, and methyl‐d3 (R)‐ and (S)‐[2.2]paracyclophane‐4‐carboxylate, exhibiting planar chirality have been measured and analyzed. The analysis of NIR and IR VCD spectra was based on the local‐mode model and the use of density functional theory (DFT), providing mechanical and electrical anharmonic terms for all CH‐bonds. The comparison of experimental and calculated spectra is satisfactory and allows one to monitor fine details in the asymmetric charge distribution in the molecules: these details consist in the harmonic frequencies, in the principal anharmonicity constants, in both the atomic polar and axial tensors and in their first and second derivatives with respect to the CH‐stretching coordinates. Chirality, 2011. © 2011 Wiley© Liss, Inc.
Wohnungsbau in Deutschland 2011 – Modernisierung oder Bestandsersatz
Authors: Walberg Dietmar
Published: September 2011

Die Studie “Wohnungsbau in Deutschland 2011 – Modernisierung oder Bestandsersatz“ entstand zwischen Juli 2010 und März 2011 durch die Arbeitsgemeinschaft für zeitgemäßes Bauen e.V. im Auftrag der Deutschen Gesellschaft für Mauerwerks‐ und Wohnungsbau e.V. (DGfM), des Bundesverbandes freier Immobilien‐ und Wohnungsunternehmen e.V. (BfW), des Zentralverbandes Deutsches Baugewerbe e.V. (ZDB), des Verbandes privater Bauherren e. V. (VPB), des Bundesverbandes Deutscher Baustofffachhandel e.V. (BDB) und des Bundesverbandes Baustoffe – Steine und Erden e.V. (BBS). Sie ermittelte erstmals in dieser Art auf der Grundlage vorliegender Daten (Energieverbräuche und Baukostenauswertungen) eine Einschätzung des baulichen und nutzungstechnischen Potentials des “kleinen Wohnungsbaus“ in Deutschland. Der in dieser Studie untersuchte “kleine Wohnungsbau“ umfasst ca. 17 Mio. Gebäude mit ca. 36 Mio. Wohnungen, davon ca. 15 Mio. Ein‐ und Zweifamilienhäuser und 2,7 Mio. kleinere Mehrfamilienhäuser mit 3 bis 12 Wohnungen und 17 Mio. Wohneinheiten, insgesamt ca. 90 % aller Wohnungen in Deutschland.

Die umfassende Bewertung des Gebäudebestands erfolgte sowohl nach energetischen Kriterien als auch hinsichtlich der Nutzbarkeit und Zukunftsfähigkeit der Grundrisse und Wohnungs‐ und Gebäudezuschnitte, umfasst also deutlich mehr Kategorien als eine nur auf energetische Verbesserung ausgerichtete Sichtweise.

Die Studie soll einen Beitrag dazu leisten, das bauliche Potential des “kleinen Wohnungsbaus“ in Deutschland sowohl hinsichtlich seines energetischen Nutzens als auch in Bezug auf die Zukunftsfähigkeit seiner Wohnungs‐ und Gebäudezuschnitte abzuschätzen.
Stand der Einführung EC 6
Authors: Seim Werner
Published: September 2011

Der EC 6 kommt. Genau genommen kommt mit DIN EN 1996‐1‐1, DIN EN 1996‐1‐2, DIN EN 1996‐2 und DIN EN 1996‐3 ein ganzes Paket neuer Normen und Vorschriften. Und schon der reine Umfang dieses Paketes – einschließlich nationaler Anwendungsdokumente werden es etwa 450 Seiten sein – macht deutlich, dass die Bemessung von Mauerwerkskonstruktionen zumindest nicht übersichtlicher wird. So umfassten z. B. die alten Bemessungsnormen DIN 1053‐1 ganze 32 bzw. DIN 1053‐3 nur 8 Seiten (ohne Brand). Ob die Bemessung auch schwieriger wird, ob sich durch die neuen Regelungen ganz neue Anwendungsgebiete für das Mauerwerk ergeben und nicht zuletzt, wann der EC 6 verbindlich anzuwenden ist, das sind die wesentlichen Fragen, denen sich dieser Beitrag widmen wird. Der einzelnen Regelungen im Detail haben sich bereits Hauschild et al. [1] in ihrem Beitrag von April diesen Jahres angenommen.
Nachhaltiges und zukunftssicheres Bauen
Authors: Hegger Manfred , Hartwig Joost
Published: September 2011

Nachhaltiges und zukunftssicheres Bauen entscheidet sich auf vielen Ebenen; Zielkonflikte sind dabei nicht auszuschließen. Ein Hauptaspekt nachhaltigen Handelns ist die effiziente Nutzung der zur Verfügung stehenden Ressourcen. Bei Gebäuden sind dies zunächst die energetischen, zunehmend aber auch die stofflichen Ressourcen und damit der gesamte Ressourceneinsatz. Die Bewertung des Ressourcenverbrauchs sollte dabei den gesamten Lebenszyklus eines Gebäudes einbeziehen, denn dieser entscheidet letztlich darüber, ob Bauen nachhaltig und zukunftssicher ist.
Brandschutz mit Mauerwerk – Aktuelle Entwicklungen in der Normung
Authors: Meyer Udo
Published: September 2011

Die Brandschutz‐Normung im Bereich Mauerwerk in Deutschland wird derzeit umfassend aktualisiert. DIN 4102‐4 soll zukünftig als “Restnorm“ nur noch ergänzende Regelungen zu den Brandschutz‐Teilen der Eurocodes enthalten. Daher läuft derzeit eine Überarbeitung. Die DIN EN 1996‐1‐2 ist als Korrekturfassung mit Ausgabe 2011‐04 veröffentlicht worden. Zusätzlich soll der nationale Anhang zu dieser Norm bis Erscheinen dieses Heftes als “Gelbdruck“ weitgehend fertig gestellt sein. Über die wichtigsten Inhalte dieses neuen Regelwerks für den Brandschutz mit Mauerwerk in Deutschland wird berichtet.

Fire design with masonry – Developments in standardization. The codes for fire design in Germany are currently under revision. All aspects that will be covered in the fire parts of the Eurocodes are to be deleted in a revised version of DIN 4102‐4. A new version of DIN EN 1996‐1‐2, including corrigenda was published in April 2011. The German national annex shall be published these days as a stable draft. This paper highlights some of the most important rules of this new standard for the fire design with masonry in Germany.
Chd7 plays a critical role in controlling left–right symmetry during zebrafish somitogenesis
Authors: Jacobs‐McDaniels Nicole L. , Albertson R. Craig
Published: September 2011

Somitogenesis is a complex process during early vertebrate development involving interactions between many factors to form a bilateral somite series. A role for chromatin remodelers in somitogenesis has not yet been demonstrated. Here, we investigate the function of chromodomain helicase DNA binding protein 7 (chd7) during zebrafish somitogenesis. We show that Chd7 deficiency leads to asymmetric segmentation of the presomitic mesoderm (PSM), as revealed by expression of the somitogenesis genes, cdx1a, dlc, her7, mespa, and ripply1. Moreover, we show that abrogation of Chd7 results in the loss of asymmetric expression of spaw in the lateral plate mesoderm, which is consistent with more general laterality defects. Based on the observation that insufficient Chd7 leads to left–right asymmetry defects during PSM segmentation, and because CHD7 has been linked to human spinal deformities, we suggest that zebrafish chd7 morphants may be a good in vivo model to examine the pathophysiology of these diseases. Developmental Dynamics 240:2272–2280, 2011. © 2011 Wiley‐Liss, Inc.
Epigenetic integration of the developing brain and face
Authors: Parsons Trish E. , Schmidt Eric J. , Boughner Julia C. , Jamniczky Heather A. , Marcucio Ralph S. , Hallgrímsson Benedikt
Published: September 2011

The integration of the brain and face and to what extent this relationship constrains or enables evolutionary change in the craniofacial complex is an issue of long‐standing interest in vertebrate evolution. To investigate brain‐face integration, we studied the covariation between the forebrain and midface at gestational days 10–10.5 in four strains of laboratory mice. We found that phenotypic variation in the forebrain is highly correlated with that of the face during face formation such that variation in the size of the forebrain correlates with the degree of prognathism and orientation of the facial prominences. This suggests strongly that the integration of the brain and face is relevant to the etiology of midfacial malformations such as orofacial clefts. This axis of integration also has important implications for the evolutionary developmental biology of the mammalian craniofacial complex. Developmental Dynamics 240:2233–2244, 2011. © 2011 Wiley‐Liss, Inc.
Polymer Conjugates of Photoinducible CO‐Releasing Molecules
Authors: Brückmann Nadine E. , Wahl Michaela , Reiß Guido J. , Kohns Marbod , Wätjen Wim , Kunz Peter C.
Published: September 2011

CO‐releasing molecules (CORMs) were coordinated to polymeric carrier systems for passive transport to tumour tissue or sites of inflammation, as described by the enhanced permeability and retention (EPR) effect. The developed conjugates consist of an organometallic fac‐Mn(CO)3 fragment, which is bound to a methacrylate or methacrylamide polymer backbone by bis(pyridylmethyl)amine‐type ligands. The resulting Mn(CO)3–polymer conjugates were investigated as photoinducible CO‐releasing molecules (photoCORMs). Furthermore, three model complexes [LMn(CO)3]O2SCF3 containing N,N,N‐ligands L = bis(pyridylmethyl)amine (bpma), bis(pyridylmethyl)ethanolamine (bpmea) and bis(pyridylmethyl)‐p‐vinylbenzylamine (bpmvba) were also investigated. The solid‐state structure of the bromide complex [(bpmea)Mn(CO)3]Br.(CH3)2CHOH (4·(CH3)2CHOH) was determined by X‐ray analysis. The complexes and the polymer conjugates show photoCORM activity with polymer molecular weights and size distributions suitable for passive drug delivery.
Copper‐Catalyzed Arylation of Oxadiamines and Polyamines
Authors: Anokhin Maxim V. , Averin Alexei D. , Beletskaya Irina P.
Published: September 2011

Copper‐catalyzed arylation of oxadiamines and polyamines aimed at the synthesis of N,N′‐diaryl derivatives using bromo‐ and iodoarenes was studied. Conversion of the starting compounds, selectivity of the arylation of primary amino groups in the presence of the secondary amino groups, and the yields of target products were shown to be strongly dependent on the nature of the oxadiamines and polyamines, aryl halides, and halogen atom, as well as on reaction conditions such as ligand, solvent, and base applied. Reliable catalytic systems were found for each type of starting amine and aryl halide affording the highest possible yields of the products of N,N′‐diarylation (65–96 %).
Synthesis of an A′B′ Precursor to Angelmicin B: Product Diversification in the Suárez Lactol Fragmentation
Authors: Li Jialiang , Todaro Louis , Mootoo David R.
Published: September 2011

We describe a synthetic strategy for the angelimicin family of anthraquinoid natural products that involves converting a central highly oxygenated decalin intermediate to the AB and A′B′ subunits. Herein, we report the synthesis of the bicyclic A′B′ subunit that complements our earlier route to the tricyclic AB framework. The differentiating tact in the two syntheses focused on controlling the Suárez radical fragmentation of lactol precursors by modulating the substrate's structural rigidity. A more flexible lactol gave the tricyclic AB framework, whereas a more rigid substrate led to the bicyclic A′B′ precursor, presumably through divergent pathways from the radical produced in the initial fragmentation step. These results establish a versatile advanced synthetic precursor for the angelimicins, and on a more general note, illustrate strategies for applying the Suárez fragmentation to diverse and complex molecular frameworks.
Toll‐like receptor 2 (TLR2)‐TLR9 crosstalk dictates IL‐12 family cytokine production in microglia
Authors: Holley Monica M. , Zhang Yongqing , Lehrmann Elin , Wood William H. , Becker Kevin G. , Kielian Tammy
Published: September 2011

Microglia are the resident mononuclear phagocytes of the CNS parenchyma and represent an initial line of defense against invading microorganisms. Microglia utilize Toll‐like receptors (TLRs) for pathogen recognition and TLR2 specifically senses conserved motifs of gram‐positive bacteria including lipoproteins, lipoteichoic acids, and peptidoglycan (PGN) leading to cytokine/chemokine production. Interestingly, primary microglia derived from TLR2 knockout (KO) mice over‐expressed numerous IL‐12 family members, including IL‐12p40, IL‐12p70, and IL‐27 in response to intact S. aureus, but not the less structurally complex TLR2 ligands Pam3CSK4 or PGN. The ability of intact bacteria to augment IL‐12 family member expression was specific for gram‐positive organisms, since numerous gram‐negative strains were unable to elicit exaggerated responses in TLR2 KO microglia. Inhibition of SYK or IRAK4 signaling did not impact heightened IL‐12 family member production in S. aureus‐treated TLR2 KO microglia, whereas PI3K, MAPK, and JNK inhibitors were all capable of restoring exaggerated cytokine expression to wild type levels. Additionally, elevated IL‐12 production in TLR2 KO microglia was ablated by a TLR9 antagonist, suggesting that TLR9 drives IL‐12 family member production following exposure to intact bacteria that remains unchecked in the absence of TLR2 signaling. Collectively, these findings indicate crosstalk between TLR2 and TLR9 pathways to regulate IL‐12 family member production by microglia. The summation of TLR signals must be tightly controlled to ensure the timely cessation and/or fine tuning of cytokine signaling to avoid nonspecific bystander damage due to sustained IL‐12 release. © 2011 Wiley Periodicals, Inc.
A new tablet for writing and drawing during functional MRI
Authors: Tam Fred , Churchill Nathan W. , Strother Stephen C. , Graham Simon J.
Published: September 2011

The article to which this erratum refers was published in Hum Brain Mapp 2011, DOI: 10.1002/hbm.21013. © 2011 Wiley‐Liss, Inc.
Planning the optimum cleaning schedule based on simulation of heat exchangers under fouling
Authors: Jin Zunlong , Chen Xiaotang , Dong Qiwu , Liu Minshan
Published: September 2011

An investigation of variations in outlet temperatures of heat exchangers under fouling was carried out. The simulation of heat exchangers was performed by employing a linear fouling deposit function. The formation of deposits reduces heat exchangers effectiveness. There is inherently a linear nature between outlet and inlet temperatures of heat exchangers. The outlet temperatures can also be affected by up‐stream exchangers serving the same streams, and the up‐stream influence can be transferred in the heat system. The mathematical model of the cleaning cycle was outlined, based on the objective function of minimizing cost in unit operation time. According to the results, some heat exchangers can be given cleaning priority when the system is shut down, in order to maximize economic benefit. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20384
Childhood treatment with psychotropic medication and development of comorbid medical conditions in adolescent‐onset bipolar disorder
Authors: Jerrell Jeanette M. , McIntyre Roger S. , Tripathi Avnish
Published: September 2011

Objective

This study aims to investigate the association between early treatment with psychotropic medications and the development of medical comorbidities in pediatric patients who develop bipolar disorder (BD).

Methods

Data from the South Carolina Medicaid program covering all medical services and medication prescriptions between January 1996 and December 2005 were used to determine the association between childhood exposure to psychotropic medications (i.e., psychostimulants, antidepressants, and antipsychotics) and the diagnosis of select comorbid medical conditions in 1841 children and adolescents diagnosed with Diagnostic and Statistical Manual IV defined BD.

Results

In separate regressions controlling for all psychotropic medications prescribed and all comorbid medical conditions diagnosed prior to the BD, hypertension and cardiovascular disorders were more likely in those prescribed second generation antipsychotics or psychostimulants, whereas obesity/overweight was more likely in those taking serotonin norepinephrine reuptake inhibitor/heterocyclic antidepressants, and asthma was more likely in those taking selective serotonin reuptake inhibitors.

Conclusion

Childhood cardiometabolic events appear to be systematically associated with specific classes of psychotropic medications, but no innate, developmental sequencing of cardiometabolic abnormalities was apparent before early adolescence in patients subsequently diagnosed and treated for BD. Copyright © 2011 John Wiley & Sons, Ltd.
Involvement of the TGFβ pathway in the regulation of α5β1 integrins by caveolin‐1 in human glioblastoma
Authors: Cosset Erika C. , Godet Julien , Entz‐Werlé Natacha , Guérin Eric , Guenot Dominique , Froelich Sébastien , Bonnet Dominique , Pinel Sophie , Plenat François , Chastagner Pascal , Dontenwill Monique , Martin Sophie
Published: September 2011

Caveolin‐1 plays a crucial role in the development of cancer and its progression. We previously reported that glioblastoma cells expressing low levels of caveolin‐1 exerted a more aggressive phenotype than cells expressing high levels. Such phenotype was due to the induction of α5β1 integrin subsequent to the depletion of caveolin‐1. Caveolin‐1 was identified as a transcriptional repressor of α5β1 integrin. The current study was designed to identify in vitro, the molecular mechanisms by which caveolin‐1 controls α5β1 integrin expression and to determine if a negative correlation between caveolin‐1 and α5β1 integrins also exists in biopsies and xenografted human brain tumors. We showed that depletion of caveolin‐1 lead to the activation of the TGFβ/TGFβRI/Smad2 pathway which in turn induced the expression of α5β1 integrins. We showed that cells expressing the lowest levels of caveolin‐1 but the highest levels of α5β1 integrins and TGFβRI were the most sensitive to a α5β1 integrin antagonist and a TGFβRI inhibitor. Screening human glioma biopsies and human glioblastoma xenografts, we isolated subgroups with either low levels of caveolin‐1 but high levels of α5β1 integrin and TGFβRI or high levels of caveolin‐1 but low levels of α5β1 integrin and TGFβRI. In conclusion, caveolin‐1 controls α5β1 integrin expression through the TGFβ/TGFβRI/Smad2 pathway. The status of caveolin‐1/α5β1 integrins/TGFβRI might be a useful marker of the tumor evolution/prognosis as well as a predictor of anti‐TGFβ or anti‐α5β1 integrin therapies.
Frequent epigenetic inactivation of the chaperone SGNE1/7B2 in human gliomas
Authors: Waha Anke , Felsberg Jörg , Hartmann Wolfgang , Hammes Jennifer , von dem Knesebeck Anna , Endl Elmar , Pietsch Torsten , Waha Andreas
Published: September 2011

In a genome‐wide screen using DMH (differential methylation hybridization) we have identified a CpG island within the 5′ region and untranslated first exon of the secretory granule neuroendocrine protein 1 gene (SGNE1/7B2) that showed hypermethylation in low‐ and high‐grade astrocytomas compared to normal brain tissue. Pyrosequencing was performed to confirm the methylation status of this CpG island in 89 astrocytic gliomas of different malignancy grades and six glioma cell lines. Hypermethylation of SGNE1/7B2 was significantly more frequent in diffuse low‐grade astrocytomas as well as secondary glioblastomas and anaplastic astrocytomas as compared to primary glioblastomas. mRNA expression analysis by real‐time RT‐PCR indicates that SGNE1/7B2 expression is downregulated in astrocytic gliomas compared to white matter samples. Treatment of glioma cells with the demethylating agent 5‐aza‐2′‐deoxycytidine restores the transcription of SGNE1/7B2. Overexpression of SGNE1/7B2 in T98G, A172 and U373MG glioblastoma cells significantly suppressed focus formation and led to a significant increase in apoptotic cells as determined by flow cytometric analysis in T98G cells. In summary, we have identified SGNE1/7B2 as a novel target silenced by DNA methylation in astrocytic gliomas. The high incidence of this alteration and the significant effects of SGNE1/7B2 on the growth and apoptosis of glioblastoma cells provide a first proof for a functional implication of SGNE1/7B2 inactivation in the molecular pathology of gliomas.
Supramolecular Chirality Using Both Cooperative and Isodesmic Self‐Assembly: hierarchical growth through competition
Authors: Gillissen Martijn A. J. , Hoeben Tom T. , Spiering A. J. H. , Vekemans Jef A. J. M. , Palmans Anja R. A. , Meijer E. W.
Published: September 2011

A novel set of chiral self‐assembling discotic molecules has been prepared based on two previously studied self‐assembling C3‐discotic systems, namely alkyl substituted benzene‐1,3,5‐tricarboxamides (alkyl‐BTAs) and 3,3′‐bis(acylamino)‐2,2′‐bipyridine substituted BTAs (BiPy‐BTAs). By replacing one of the three bipyridyl side chains by an alkyl chain we have prepared a hybrid system that shows properties of both parent compounds. Due to the different packing parameters and mechanisms of self‐assembly of the parent BTAs, one might expect a lack of ordering in such a hybrid system. However, we observe columnar mesophases and unique self‐assembly behavior in solution. We propose that the solution self‐assembly passes through three stages. First, disordered aggregates are formed that evolve into ordered aggregates via an isodesmic process. Finally, these ordered aggregates rearrange in a cooperative fashion into a higher ordered structure. Through the interplay between π–π interactions and H‐bonding, the hybrid molecules combine the cooperative self‐assembly behavior of alkyl‐BTAs with the isodesmic behavior of BiPy‐BTA discotics. This work shows that merging two systems with seemingly incompatible requirements can lead to new and complex self‐assembly behavior.
Chemical Synthesis of Naturally‐Occurring Cyclic Mini‐Proteins from Plants and Animals
Authors: Conibear Anne C. , Craik David J.
Published: September 2011

Cyclization of a peptide backbone is a relatively minor modification in one sense, in that it involves the addition of just one extra peptide bond to a protein sequence, but the consequences of this addition can be profound in terms of stability of the protein. Until recently, most studies of head‐to‐tail cyclic peptides were limited to rather small peptides, typically less than 12 amino acids in size, but over the last decade it has become clear that cyclization is readily applicable to a wide range of peptides and proteins, including those that contain one or more disulfide bonds. This article describes studies involving the solid phase peptide synthesis of two classes of disulfide‐rich peptides that contain a cystine knot and a cystine ladder motif, respectively. The cyclotides comprise around 30 amino acids, with their six conserved cysteine residues arranged in a cystine knot motif, whereas the θ‐defensins comprise 18 amino acids with the cysteine residues forming a cystine ladder.
Solvation properties ofN‐acetyl‐β‐glucosamine: Molecular dynamics study incorporating electrostatic polarization
Authors: Zhong Yang , Bauer Brad A. , Patel Sandeep
Published: September 2011

N‐Acetyl‐β‐glucosamine (NAG) is an important moiety of glycoproteins and is involved in many biological functions. However, conformational and dynamical properties of NAG molecules in aqueous solution, the most common biological environment, remain ambiguous due to limitations of experimental methods. Increasing efforts are made to probe structural properties of NAG and NAG‐containing macromolecules, like peptidoglycans and polymeric chitin, at the atomic level using molecular dynamics simulations. In this work, we develop a polarizable carbohydrate force field for NAG and contrast simulation results of various properties using this novel force field and an analogous nonpolarizable (fixed charge) model. Aqueous solutions of NAG and its oligomers are investigated; we explore conformational properties (rotatable bond geometry), electrostatic properties (dipole moment distribution), dynamical properties (self‐diffusion coefficient), hydrogen bonding (water bridge structure and dynamics), and free energy of hydration. The fixed‐charge carbohydrate force field exhibits deviations from the gas phase relative rotation energy of exocyclic hydroxymethyl side chain and of chair/boat ring distortion. The polarizable force field predicts conformational properties in agreement with corresponding first‐principles results. NAG–water hydrogen bonding pattern is studied through radial distribution functions (RDFs) and correlation functions. Intermolecular hydrogen bonding between solute and solvent is found to stabilize NAG solution structures while intramolecular hydrogen bonds define glycosidic linkage geometry of NAG oligomers. The electrostatic component of hydration free energy is highly dependent on force field atomic partial charges, influencing a more favorable free energy of hydration in the fixed‐charge model compared to the polarizable model. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Modeling the interactions between polyoxometalates and their environment
Authors: Courcot Blandine , Bridgeman Adam J.
Published: September 2011

To develop a force field suitable both for polyoxometalates (POMs) and organic cations, the Merck molecular force field 94x (MMFF94x) has been selected to describe the counterions used in POMs synthesis and has been combined with our force field optimized for type‐II POMs with electrostatic and Van der Waals interactions included in the potential. Nontransferability of force fields is well‐known and, to overcome this limitation, a charge‐scaling factor (SF) has been introduced and optimized to tune the POMs force field parameters and adapt them to MMFF94x. The mixed MMFF94x/POMFF‐II force field has been optimized and tested on different clusters based on hepta‐molybdate. To validate our mixed force field comparison of the results obtained after molecular mechanics (MM), geometry optimizations with density‐functional (DFT) calculations have been performed on the smallest system of interest. This has enabled a study of the accuracy of different functionals, especially on the description of hydrogen bonding, to be made. Results are promising in terms of structural accuracy. MM geometry optimization can be used on small POM clusters, competing reasonably well with DFT. When quantum approaches increase considerably the computational cost because of the size of the system studied, MM can be used, with the small reservation that even if the charge SF introduced improves the performance of the force field, further optimizations of the nonbonded term and the model used for the atomic charges may be necessary in further studies. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Kinetic isotope effects calculated with the instanton method
Authors: Meisner Jan , Rommel Judith B. , Kästner Johannes
Published: September 2011

The ring‐opening reaction of the cyclopropylcarbinyl radical proceeds via heavy‐atom tunneling at low temperature. We used instanton theory to calculate tunneling rates and kinetic isotope effects with on‐the‐fly calculation of energies by density functional theory (B3LYP). The accuracy was verified by explicitly correlated coupled‐cluster calculations (UCCSD(T)‐F12). At cryogenic temperatures, we found protium/deuterium KIEs up to 13 and inverse KIEs down to 0.2. We also studied an intramolecular tautomerization reaction. A simple and computationally efficient method is proposed to calculate KIEs with the instanton method: the instanton path is assumed to be independent of the atomic masses. This results in surprisingly good estimates of the KIEs for the cyclopropylcarbinyl radical and for the secondary KIEs of the tautomerization. Challenges and capabilities of the instanton method for calculating KIEs are discussed. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Theoretical and practical barriers to practitioners' willingness to seek training in empirically supported treatments
Authors: Stewart Rebecca E. , Chambless Dianne L. , Baron Jonathan
Published: September 2011

To identify barriers to the dissemination of empirically supported treatments (ESTs), a random sample of psychologists in independent practice (N=1291) was asked to complete measures of attitudes towards ESTs and willingness to attend a 3‐hour, 1‐day, or 3‐day workshop in an EST of their choice. The strongest predictor of unwillingness to obtain EST training was the amount of time and cost required for the workshop, followed by objections to the need for EST training. Psychodynamic (compared to cognitive‐behavioral) and more experienced practitioners agreed more strongly with the objections to ESTs overall, as did those whose graduate schools had not emphasized psychotherapy research. Results suggest that both practical and theoretical barriers are significant obstacles to EST dissemination. © 2011 Wiley Periodicals, Inc. J Clin Psychol 67:1–16, 2011.
MRT letter: Segmentation and texture‐based classification of breast mammogram images
Authors: Naveed Nawazish , Jaffar M. Arfan , Choi Tae‐Sun
Published: September 2011

Breast cancer is the most common cancer diagnosed among women. In this article, support vector machine is used to classify digital mammogram images into malignant and benign. Wiener filter is used to handle the possible quantum noise, which is more likely to occur in mammograms. Stack‐based connected component method is proposed for background removal, and the image is enhanced using retinax method. Seeded region growing algorithm is used to remove the pectoral muscle part of the mammogram. We have extracted 13 different multidomains' features for classification. Results show the superiority of the proposed algorithm in terms of sensitivity, specificity, and accuracy. We have used MIAS database of mammography for experimentation. Microsc. Res. Tech., 2011. © 2011 Wiley Periodicals, Inc.
Development of a hydroxyapatite coating containing silver for the prevention of peri‐prosthetic infection
Authors: Ghani Yaser , Coathup Melanie J. , Hing Karin A. , Blunn Gordon W.
Published: September 2011

We hypothesized that the electrochemical deposition of hydroxyapatite (EHA) can be used to incorporate silver (Ag), providing a controlled and sustained release of Ag ions at a bactericidal concentration. Six groups were investigated: electrochemical co‐precipitation of HA and Ag (EHA/Ag); EHA pre‐coated discs treated in AgN03 (EHA/AgN03); plasma sprayed HA (PHA) pre‐coated discs treated in AgN03 (PHA/AgN03); EHA with 2 “layers” of Ag (EHA/Ag/2 layers); EHA coating only; and PHA coating only. Scanning electron microscopy (SEM) and energy dispersive X‐ray (EDX) and X‐ray diffraction (XRD) analyses quantified coating thickness, calcium/phosphorous ratio, and % atomic silver content, respectively. Inductively coupled plasma‐mass spectrometry quantified the amount of Ag released in phosphate‐buffered saline, and zone of inhibition tests on agar plates using a lawn of Staph aureus were quantified in each group. XRD and EDX analysis confirmed the presence of Ag in all coatings. EHA coated discs with two layers of Ag and the EHA discs soaked in AgN03 showed significantly higher zones of inhibition at all time points when compared with all other groups (except PHA/AgN03 on day 0). This study demonstrated that Ag ions can be incorporated into a HA coating using an electrochemical technique. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:356–363, 2012
Late Holocene vertical land motion and relative sea‐level changes: lessons from the British Isles
Authors: Shennan Ian , Milne Glenn , Bradley Sarah
Published: September 2011

Vertical land motion caused by continuing glacial isostatic adjustment is one of several important components of sea‐level change and is not limited just to previously glaciated regions. A national‐scale analysis for the British Isles shows an ellipse of present‐day relative uplift (relative sea‐level fall), ∼1.2 mm a−1, broadly centred on the deglaciated mountains of Scotland. The pattern of three foci of relative subsidence, ∼1 mm a−1, results from the additional interactions of the deglacial meltwater load on the Atlantic basin and the continental shelf, and the signal due to far‐field ice sheets. At a local scale, sediment compaction can more than double the rate of relative land subsidence. Relative land‐level change (the negative of relative sea‐level change) is not the same as vertical land motion. There is a spatial pattern in the difference between relative land‐level change and vertical land motion, with differences at present of approximately −0.1 to −0.3 mm a−1 around the British Isles and +2.5 to −1.5 mm a−1 globally. For the wider scientific and user community, whether or not the differences are considered significant will depend upon the location, time frame and spatial scale of the study that uses such information. Copyright © 2011 John Wiley & Sons, Ltd.
Novel Glycopolymer Brushes via ATRP: 2. Thermal and Mechanical Properties
Authors: Fleet Reda , van den Dungen Eric T. A. , Klumperman Bert
Published: September 2011

The thermal and mechanical properties of a series of novel glycopolymer brushes with various degrees of polymerization of the backbone and various grafting densities are established. Modulated differential scanning calorimetry (MDSC) is found to be an effective tool for the characterization of the thermal behavior of these glycopolymer brushes. There is little difference among the glass transition temperatures of the different glycopolymer brushes. The elastic features of each glycopolymer predominate (G′ > G″) at low frequency, while at higher frequencies the G″ curve overtakes the G′ curve, indicating the predominance of the viscous response.
m‐isometries on Banach spaces
Authors: Bayart Frédéric
Published: September 2011

We introduce the notion of an m‐isometry of a Banach space, following a definition of Agler and Stankus in the Hilbert space setting. We give a first approach to the general theory of these maps. Then, we focus on the dynamics of m‐isometries, showing that they are never N‐supercyclic. This result is new even on a Hilbert space, and even for isometries on a general Banach space.