bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tetranuclear Copper(II) Complexes Bearing Cu4O6 and Cu4O4 Cores: Synthesis, Structure, Magnetic Properties, and DFT Study
Authors: Banerjee Atanu , Singh Reena , Mondal Pallab , Colacio Enrique , Rajak Kajal Krishna 
Published: January 2010

AbstractThe reaction of Cu(ClO4)2·6H2O with N4O3 coordinating heptadentate (H3L1) and N2O coordinating tridentatereduced Schiff base (HL2) ligands yielded copper(II) tetranuclear complexes [Cu4(L1)2](ClO4)2 (1) and [Cu4(L2)4](ClO4)4 (2), respectively. Complex 1 crystallizes in the cubic system, space group Fd$\bar {3}$c, with unit‐cell parameters a = b = c = 43.124(5) Å, Z = 48, whereas complex 2 crystallizes in the space group P41212 in the tetragonal crystal system with Z = 8 and unit‐cell parameters a = b = 17.113(4) Å, c = 44.150(4) Å. The X‐ray structures of 1 and 2 have revealed a Cu4O6 core in 1 and a Cu4O4 core in 2. Complexes 1 and 2 show intramolecular antiferromagnetic interaction with moderate |J| values (104.2 cm–1 for 1 and 155.1 cm–1 for 2). The moderate |J| value can be explained by the existence of only one bridging alkoxido group between each pair of copper(II) atoms and the out‐of‐plane displacement of the alkoxido carbon atom from the Cu–O–Cu plane. Broken‐symmetry density functional theory (BSDFT) has been used to justify the exchange pathways.
Tetranuclear N‐Heterocyclic Carbene Mercury(II) Complexes Containing Triply Deprotonated Acetonitrile: Synthesis and Structural Studies
Authors: Liu Qing‐Xiang , Li Shu‐Juan , Zhao Xiao‐Jun , Zang Yan , Song Hai‐bin , Guo Jian‐Hua , Wang Xiu‐Guang 
Published: January 2010

AbstractIn the presence of KOtBu, bis[N‐(nPr)benzimidazoliumylmethyl]durene bromide (1a) and bis[N‐(nBu)benzimidazoliumylmethyl]durene bromide (1b) were treated with HgBr2 in CH3CN, respectively, to afford two novel tetranuclear NHC–mercury(II) complexes, [durene(CH2bimynPr)2Hg2(CCN)Hg2Br5] (2a) and [durene(CH2bimynBu)2Hg2(CCN)Hg2Br5] (2b; durene = 1,2,4,5‐tetramethylbenzene, bimy = benzimidazol‐2‐ylidene, CCN = triply deprotonated acetonitrile). In 2a or 2b, a funnel‐like molecular structure is formed by a triply deprotonated acetonitrile, a bidentate biscarbene ligand, the HgII ions, and the bromide ions. Additionally, analysis of the crystal packings of 2a or 2b reveals that the double‐stranded 1D supramolecular chains are formed through intermolecular weak interactions, including π–π stacking interactions, C–H···Br hydrogen bonds, and weak O···Hg bonds.
Mimics of a R22(8) Hydrogen‐Bond Dimer Motif: Synthesis and Influence on the Crystallisation of Sulfathiazole and Sulfapyridine
Authors: Lawrence Simon E. , McAuliffe Marie T. , Moynihan Humphrey A. 
Published: January 2010

AbstractThe bis[4‐(hydroxyamino)phenylsulfonyl]piperazine 5, diketopiperazine 10 and benzene 14 were synthesised as mimics of an R22(8) motif, which occurs in one crystal polymorph of sulfathiazole and in several polymorphs of sulfapyridine. When present in crystallisations of sulfathiazole and sulfapyridine, these mimics were found to have little or no effect under crystallisation conditions that favour the formation of polymorphs not containing R22(8) motifs. However, the mimics were found to completely or partially inhibit the formation of form I sulfathiazole, which contains the R22(8) dimer, in crystallisations of sulfathiazole from 1‐propanol. In crystallisations of sulfapyridine, the mimics were found to promote the formation of form III, which does not contain the R22(8) motif. These compounds therefore appear to act as “tailor‐made” additives, displaying polymorph‐selective crystal nucleation inhibition based on interaction with hydrogen‐bond network motifs.
The function of GluR1 and GluR2 in cerebellar and hippocampal LTP and LTD is regulated by interplay of phosphorylation andO‐GlcNAc modification
Authors: Din Nasirud , Ahmad Ishtiaq , ul Haq Ikram , Elahi Sana , Hoessli Daniel C. , Shakoori Abdul Rauf 
Published: January 2010

AbstractLong‐term potentiation (LTP) and long‐term depression (LTD) are the current models of synaptic plasticity and widely believed to explain how different kinds of memory are stored in different brain regions. Induction of LTP and LTD in different regions of brain undoubtedly involve trafficking of AMPA receptor to and from synapses. Hippocampal LTP involves phosphorylation of GluR1 subunit of AMPA receptor and its delivery to synapse whereas; LTD is the result of dephosphorylation and endocytosis of GluR1 containing AMPA receptor. Conversely the cerebellar LTD is maintained by the phosphorylation of GluR2 which promotes receptor endocytosis while dephosphorylation of GluR2 triggers receptor expression at the cell surface and results in LTP. The interplay of phosphorylation andO‐GlcNAc modification is known as functional switch in many neuronal proteins. In this study it is hypothesized that a same phenomenon underlies as LTD and LTP switching, by predicting the potential of different Ser/Thr residues for phosphorylation,O‐GlcNAc modification and their possible interplay. We suggest the involvement ofO‐GlcNAc modification of dephosphorylated GluR1 in maintaining the hippocampal LTD and that of dephosphorylated GluR2 in cerebral LTP. J. Cell. Biochem. 109: 585–597, 2010. © 2010 Wiley‐Liss, Inc.
RB gene family: Genome‐wide ChIP approaches could open undiscovered roads
Authors: Rizzolio Flavio , Esposito Luca , Muresu Debora , Fratamico Robert , Jaraha Ranna , Caprioli Gianluca Vosa , Giordano Antonio 
Published: January 2010

AbstractMany in vitro and reporter assays have helped to clarify how transcription factors regulate gene transcription. Today, it is important to decode the map of all transcription factor binding sites in the genome context. Chromatin immunoprecipitation followed by genome‐wide analyses have tremendously opened new ways to analyze the mechanisms of action of DNA binding factors, cofactors and epigenetic modifications. It is now possible to correlate these regulatory mechanisms with genomic features such as the promoter, enhancer, silencer, intragenic, and intergenic DNA sequences. These approaches help to clarify the complex rules that govern many biological processes. In this review we discuss the genome‐wide approaches applied to the retinoblastoma gene family (RBF), the central player of cell cycle control. There are also new, possible directions that are suggested within the review that can be followed to further explore the role of each pRb members in the transcriptional networks of the cell. J. Cell. Biochem. 109: 839–843, 2010. © 2010 Wiley‐Liss, Inc.
TAp63 is a transcriptional target of NF‐κB
Authors: Wu Junfeng , Bergholz Johann , Lu Jinin , Sonenshein Gail E. , Xiao Zhi‐Xiong Jim 
Published: January 2010

AbstractThe p53 homologue p63 encodes multiple protein isoforms either with (TA) or without (ΔN) the N‐terminal transactivation domain. Accumulating evidence indicates that TAp63 plays an important role in various biological processes, including cell proliferation, differentiation, and apoptosis. However, how TAp63 is regulated remains largely unclear. In this study, we demonstrate that NF‐κB induces TAp63 gene expression. The responsible elements for NF‐κB‐mediated TAp63 induction are located within the region from −784 to −296 bp in the TAp63 promoter, which contains two NF‐κB binding sites. Ectopic expression of RelA stimulates TAp63 promoter‐driven reporter activity and increases endogenous TAp63 mRNA levels. Inhibition of NF‐κB by IκBα super‐repressor or with a chemical inhibitor leads to down regulation of TAp63 mRNA expression and activity. In addition, mutations in the critical NF‐κB‐binding sites significantly abolish the effects of NF‐κB on TAp63. Activation of NF‐κB by TNFα enhances p50/RelA binding to the NF‐κB binding sites. Furthermore, we show that an Sp1 site adjacent to the NF‐κB sites plays a role in NF‐κB‐mediated upregulation of TAp63. Taken together, these data reveal that TAp63 is a transcriptional target of NF‐κB, which may play a role in cell proliferation, differentiation and survival upon NF‐κB activation by various stimuli. J. Cell. Biochem. 109: 702–710, 2010. © 2010 Wiley‐Liss, Inc.
Bifidobacteria inhibit the inflammatory response induced by gliadins in intestinal epithelial cells via modifications of toxic peptide generation during digestion
Authors: Laparra J.M. , Sanz Y. 
Published: January 2010

AbstractCeliac disease (CD) is a chronic enteropathy triggered by intake of gliadin, the toxic component of gluten. This study aims at evaluating the capacity of different Bifidobacterium strains to counteract the inflammatory effects of gliadin‐derived peptides in intestinal epithelial (Caco‐2) cells. A commercial extract of several gliadin (Gld) types (α, β, γ, ϖ) was subjected to in vitro gastrointestinal digestion (pepsin at pH 3, pancreatin‐bile at pH 6), inoculated or not with cell suspensions (108 colony forming units/ml) of either B. animalis IATA‐A2, B. longum IATA‐ES1, or B. bifidum IATA‐ES2, in a bicameral system. The generated gliadin‐derived peptides were identified by reverse phase‐HPLC–ESI‐MS/MS. Caco‐2 cell cultures were exposed to the different gliadin peptide digestions (0.25 mg protein/ml), and the mRNA expression of nuclear factor kappa‐B (NF‐κB), tumor necrosis factor α (TNF‐α), and chemokine CXCR3 receptor were analyzed by semi‐quantitative reverse transcriptase‐polymerase chain reaction (RT‐PCR) in stimulated cells. The production of the pro‐inflammatory markers NF‐κB p50, TNF‐α, and IL‐1β (interleukine 1β) by Caco‐2 cells was also determined by ELISA. The peptides from gliadin digestions inoculated with bifidobacteria did not exhibit the toxic amino acid sequences identified in those noninoculated (α/β‐Gld [158–164] and α/β‐Gld [122‐141]). The RT‐PCR analysis evidenced a down‐regulation in mRNA expression of pro‐inflammatory biomarkers. Consistent with these results the production of NF‐κB, TNF‐α, and IL‐1β was reduced (18.2–22.4%, 28.0–64.8%, and abolished, respectively) in cell cultures exposed to gliadin digestions inoculated with bifidobacteria. Therefore, bifidobacteria change the gliadin‐derived peptide pattern and, thereby, attenuate their pro‐inflammatory effects on Caco‐2 cells. J. Cell. Biochem. 109: 801–807, 2010. © 2009 Wiley‐Liss, Inc.
Involvement of integrins α3β1 and α5β1 and glycoprotein IIb in megakaryocyte‐induced osteoblast proliferation
Authors: Lemieux Justin M. , Horowitz Mark C. , Kacena Melissa A. 
Published: January 2010

AbstractAs the prevalence of osteoporosis is expected to increase over the next few decades, the development of novel therapeutic strategies to combat this disorder becomes clinically imperative. These efforts draw extensively from an expanding body of knowledge pertaining to the physiologic mechanisms of skeletal homeostasis. To this body of knowledge, we contribute that cells of hematopoietic lineage may play a crucial role in balancing osteoblastic bone formation against osteoclastic resorption. Specifically, our laboratory has previously demonstrated that megakaryocytes (MKs) can induce osteoblast (OB) proliferation in vitro, but do so only when direct cell‐to‐cell contact is permitted. To further investigate the nature of this interaction, we have effectively neutralized several adhesion molecules known to function in the analogous interaction of MKs with another cell type of mesenchymal origin—the fibroblast (FB). Our findings implicate the involvement of fibronectin/RGD‐binding integrins including α3β1 (VLA‐3) and α5β1 (VLA‐5) as well as glycoprotein (gp) IIb (CD41), all of which are known to be expressed on MK membranes. Furthermore, we demonstrate that interleukin (IL)‐3 can enhance MK‐induced OB activation in vitro, as demonstrated in the MK–FB model system. Taken together, these results suggest that although their physiologic and clinical implications are very different, these two models of hematopoietic–mesenchymal cell activation are mechanistically analogous in several ways. J. Cell. Biochem. 109: 927–932, 2010. © 2010 Wiley‐Liss, Inc.
Improved in vivo gene transfer into tumor tissue by stabilization of pseudodendritic oligoethylenimine‐based polyplexes
Authors: Russ Verena , Fröhlich Thomas , Li Yunqiu , Halama Anna , Ogris Manfred , Wagner Ernst 
Published: January 2010

AbstractBackgroundHD O is a low molecular weight pseudodendrimer containing oligoethylenimine and degradable hexanediol diacrylate diesters. DNA polyplexes display encouraging gene transfer efficiency in vitro and in vivo but also a limited stability under physiological conditions. This limitation must be overcome for further development into more sophisticated formulations.MethodsHD O polyplexes were laterally stabilized by crosslinking surface amines via bifunctional crosslinkers, bioreducible dithiobis(succimidyl propionate) (DSP) or the nonreducible analog disuccinimidyl suberate (DSS). Optionally, in a subsequent step, the targeting ligand transferrin (Tf) was attached to DSP‐linked HD O polyplexes via Schiff base formation between HD O amino groups and Tf aldehyde groups, which were introduced into Tf by periodate oxidation of the glycosylation sites.ResultsCrosslinked DNA polyplexes showed an increased stability against exchange reaction by salt or heparin. Disulfide bond containing DSP‐linked polyplexes were susceptible to reducing conditions. These polyplexes displayed the highest gene expression levels in vitro and in vivo (upon intratumoral application in mice), and these were significantly elevated and prolonged over standard or DSS‐stabilized HD O formulations. DSP‐stabilized HD O polyplexes with or without Tf coating were well‐tolerated after intravenous application. High gene expression levels were found in tumor tissue, with negligible gene expression in any other organ.ConclusionsLateral stabilization of HD O polyplexes with DSP crosslinker enhanced gene transfer efficacy and was essential for the incorporation of a ligand (Tf) into a stable particle formulation. Copyright © 2010 John Wiley & Sons, Ltd.
Polyethylenimine/small interfering RNA‐mediated knockdown of vascular endothelial growth factor in vivo exerts anti‐tumor effects synergistically with Bevacizumab
Authors: Höbel Sabrina , Koburger Ivette , John Matthias , Czubayko Frank , Hadwiger Philipp , Vornlocher Hans‐Peter , Aigner Achim 
Published: January 2010

AbstractBackgroundRNA interference is a powerful method for the knockdown of pathologically relevant genes. The in vivo delivery of siRNAs, preferably through systemic, nonviral administration, poses the major challenge in the therapeutic application of RNAi. Small interfering RNA (siRNA) complexation with polyethylenimines (PEI) may represent a promising strategy for siRNA‐based therapies and, recently, the novel branched PEI F25‐LMW has been introduced in vitro. Vascular endothelial growth factor (VEGF) is frequently overexpressed in tumors and promotes tumor growth, angiogenesis and metastasis and thus represents an attractive target gene in tumor therapy.MethodsIn subcutaneous tumor xenograft mouse models, we established the therapeutic efficacy and safety of PEI F25‐LMW/siRNA‐mediated knockdown of VEGF. In biodistribution and siRNA quantification studies, we optimized administration strategies and, employing chemically modified siRNAs, compared the anti‐tumorigenic efficacies of: (i) PEI/siRNA‐mediated VEGF targeting; (ii) treatment with the monoclonal anti‐VEGF antibody Bevacizumab (Avastin®); and (iii) a combination of both.ResultsEfficient siRNA delivery is observed upon systemic administration, with the biodistribution being dependent on the mode of injection. Toxicity studies reveal no hepatotoxicity, proinflammatory cytokine induction or other side‐effects of PEI F25‐LMW/siRNA complexes or polyethylenimine, and tumor analyses show efficient VEGF knockdown upon siRNA delivery, leading to reduced tumor cell proliferation and angiogenesis. The determination of anti‐tumor effects reveals that, in pancreas carcinoma xenografts, single treatment with PEI/siRNA complexes or Bevacizumab is already highly efficacious, whereas, in prostate carcinoma, synergistic effects of both treatments are observed.ConclusionsPEI F25‐LMW/siRNA complexes, which can be stored frozen as opposed to many other carriers, represent an efficient, safe and promising avenue in anti‐tumor therapy, and PEI/siRNA‐mediated, therapeutic VEGF knockdown exerts anti‐tumor effects. Copyright © 2010 John Wiley & Sons, Ltd.
Investigation of interaction of benzoquinones and naphthoquinones with substituted hydrazides
Authors: Hassan Alaa A. , Ibrahim Yusria R. , Shawky Ahmed M. 
Published: January 2010

Abstract
magnified imageNucleophilic attack by substituted hydrazides on C‐2, C‐3 of 2,3,5,6‐tetrachloro‐1,4‐benzoquinone and 2,3‐dichloro‐1,4‐naphthoquinone initiates the formation of benzo[e][1,3,4]oxadiazine and benzo‐ as well as naphthoxadiazepine derivatives. On the other hand, substituted hydrazides attack 1,4‐naphthoquinone‐2,3‐dicarbonitrile to form benzo[f]indazole‐4,9‐dione derivatives. A rationale for the conversions observed is presented. J. Heterocyclic Chem., 2010.
Synthesis of 2‐arylquinolin‐4(1H)‐ones and their transformation to N‐alkylated and O‐alkylated derivatives
Authors: Mphahlele Malose J. 
Published: January 2010

Abstract
magnified image2‐Aryl‐4‐quinolones are versatile synthetic intermediates and several articles continue to appear in literature describing their synthesis, chemical transformation, structural properties, and biological activities. Their versatility as synthetic intermediates is a consequence of 4‐quinolone moiety, which contains several reactive centers (positions 1, 3, and 4) for possible functionalization and can also enable different degree of unsaturation. In this review, we describe methods developed to‐date for the synthesis of 2‐arylquinolin‐4(1H)‐ones and their N‐alkylated and O‐alkylated derivatives. J. Heterocyclic Chem., 2010.
One pot synthesis of [1,3]‐oxazine and [1,3]‐thiazine derivatives under thermal and microwave conditions
Authors: Tumtin S. , Phucho I. T. , Nongpiur A. , Nongrum R. , Vishwakarma J. N. , Myrboh B. , Nongkhlaw R. L. 
Published: January 2010

Abstract
magnified imageA simple and efficient synthesis of substituted benzo [1,3] oxazine and benzo [1,3] thiazine derivatives under conventional heating, as well as microwave irradiation is reported. The compounds were obtained by the reaction of electron rich phenols, formaldehyde, and aromatic amines in methanol. Reactions which take 12–16 hr under conventional heating were successfully completed within a few minutes under microwave irradiation (solventless) with moderate to excellent yields. J. Heterocyclic Chem., 2010.
The development of an ecofriendly procedure for alkaline metal (II) sulfate promoted synthesis of N,N′‐dimethyl substituted (unsubstituted)‐4‐aryl‐3,4‐dihydropyrimidones (thiones) and corresponding bis‐analogues in aqueous medium: Evaluation by green chemistry metrics
Authors: Mukhopadhyay Chhanda , Datta Arup 
Published: January 2010

Abstract
magnified imageDifferent alkaline metal (II) sulfates were used as catalysts for the N,N′‐dimethyl substituted as well as unsubstituted 4‐aryl‐3,4‐dihydropyrimidones (thiones) and their corresponding bis‐analogues in aqueous medium. Among the various salts, MgSO4·7H2O (Epsom salt) proved to be the best catalyst giving the desired products in good to excellent yields. This catalyst enables the construction of a series of compound libraries particularly for N,N′‐dimethyl substituted DHPM's whose synthesis is very rare in the literature. The reaction on a wide variety substrates was evaluated by the application of green chemistry metrics and a very good correlation was obtained. J. Heterocyclic Chem., 2010.
A simple, mild, and efficient procedure for high‐yield synthesis of benzimidazoles using coppertriflate as catalyst
Authors: Chari M. Adharvana , Sadanandam P. , Shobha D. , Mukkanti K. 
Published: January 2010

Abstract
magnified imageCopper triflate has been found to be an efficient catalyst for the synthesis of benzimidazoles from o‐phenylenediamine and aldehydes at reflux temperature under acetonitrile solvent. This new method consistently has the advantage of excellent yields (74–95%) at reflux temperature. J. Heterocyclic Chem., 2010.
Monitoring dehydration kinetics using simultaneous thermal and spectral methods
Authors: Beard Mark A. , Ghita Oana R. , McCabe James , Evans Kenneth E. 
Published: January 2010

AbstractThe dehydration kinetics of theophylline monohydrate is a two‐stage process. The first stage involves loosening of the crystal water followed by a second stage in which the water evaporates from the sample. During differential scanning calorimetry (DSC) measurements, the kinetics of the two stages can be dramatically altered because of the sample environment and DSC pan type. In‐depth understanding of how the sample environment alters the dehydration process and the kinetics involved requires more than DSC experiments alone. This paper describes the use of a novel, simultaneous thermal and spectral technique to monitor the dehydration kinetics of theophylline monohydrate. The analysis of the results obtained on the combined DSC‐near‐infrared and DSC‐Raman equipment clearly detects the two stages of the dehydration process and the polymorphic structural changes that take place. The combined technique provides a powerful method to monitor the dehydration of hydrous systems. Copyright © 2010 John Wiley & Sons, Ltd.
A Raman spectroscopic and TEM study on the structural evolution of Na2Ti3O7 during the transition to Na2Ti6O13
Authors: Liu Hongwei , Yang Dongjiang , Zheng Zhanfeng , Ke Xuebin , Waclawik Eric , Zhu Huaiyong , Frost Ray L. 
Published: January 2010

AbstractThe synthesis of sodium hexatitanate from sodium trititanate was characterized by Raman spectroscopy, X‐ray diffraction (XRD) and high‐resolution transmission electron microscopy (HRTEM). The structural evolution from trititanate to hexatitanate was studied using Raman spectra, XRD and HRTEM techniques. It was found that the Raman bands at 279 cm−1 corresponding to very long TiO bonds and at 883 cm−1 corresponding to the very short TiO bonds decrease in intensity and finally disappear during the transition from sodium trititanate to sodium hexatitanate. The band at 922 cm−1 corresponding to an intermediate‐length TiO bond was observed to become stronger with the increase in temperature, indicating that there is no terminal oxygen atom in the crystal structure of Na2Ti6O13 and that all the oxygen atoms become linearly coordinated by two titanium atoms. Furthermore, the TiO6 octahedron in Na2Ti6O13 are more regular because the very long (2.2 Å) or very short (1.7 Å) TiO bonds disappear. It is revealed that the phase transition from trititanate to hexatitanate is a step‐by‐step slipping process of the TiO6 octahedral slabs with the loss of sodium cations, and a new phase with formula Na1.5H0.5Ti3O7 has been discovered as an intermediate phase to interlink Na2Ti3O7 and Na2Ti6O13. Copyright © 2010 John Wiley & Sons, Ltd.
Raman spectra and simulation of cis‐ and trans‐cyclooctene for conformational analysis compared to inelastic neutron scattering
Authors: Kulterer Martin R. , Hudson Bruce S. 
Published: January 2010

AbstractSimulated and measured Raman spectra are used to determine the molecular conformation of trans‐cyclooctene. This is the first reported Raman spectrum of this highly strained species. A crown structure results in a computed Raman spectrum, which is in good agreement with the experiment; a chair structure does not. Comparison is made with the case of cis‐cyclooctene. The computed structure and limitations of the method of conformational analysis are discussed. In particular, the relative merits of Raman spectroscopy in comparison with infrared and inelastic neutron scattering (INS) are evaluated using computed spectra for all three methods and comparison of the observed INS for cis‐cyclooctene with that computed for two conformations. It is concluded that the combination of computed and observed Raman spectra provides a useful method for conformational analysis for cases of this type. Copyright © 2010 John Wiley & Sons, Ltd.