bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Synthesis of MII Complexes with a Schiff Base containing an Amido Group. Crystal Structure of a Cobalt(II) Complex with a Reorganised Ligand
Authors: Rodríguez M. Jesús , Fernández M. Isabel , González‐Noya Ana M. , Maneiro Marcelino , Pedrido Rosa , Vázquez Miguel , Donnadieu Bruno , Bermejo Manuel R. 
Published: August 2005

AbstractM(HL)(H2O)n complexes have been obtained by the electrochemical reaction of Fe, Co, Ni, Cu, Zn and Cd anodes with the potentially pentadentate and trianionic asymmetrical Schiff base 3‐aza‐N‐{2‐[1‐aza‐2‐(5‐nitro‐2‐hydroxylphenyl)‐vinyl]phenyl}‐4‐(5‐nitro‐2‐hydroxyphenyl)but‐3‐enamide (H3L), containing a hard amido donor atom. The complexes have been characterized by elemental analysis, mass spectrometry, IR and 1H NMR spectroscopies, magnetic measurements and molar conductivities. Co(HL)(H2O) (2) has been found to rearrange in DMF solution into a crystallographically solved octahedral complex, CoL1(H2O)2 (7) [where H2L1 is the symmetrical Schiff base ligand N,N′‐(1,2‐phenylene)‐bis(5‐nitro‐3‐hydroxysalicylidenimine)]. A hydrolysis mechanism is discussed to explain this rearrangement.
Synthesis and Characterization of α‐Titanium Phosphate/Propylamine Intercalation Compounds Containing Transition‐Metal Ions
Authors: Alfonso Belén F. , Trobajo Camino , Salvadó Miguel A. , Pertierra Pilar , García‐Granda Santiago , Rodríguez‐Fernández Jesús , Blanco Jesús A. , García José R. 
Published: August 2005

AbstractPolycrystalline intercalated TiMxH2−nx(PO4)2· yC3H7NH2·wH2O compounds with transition metal (TM) ions (Mn+ = Co2+, Ni2+, Fe3+ or Cr3+) have been prepared by means of an indirect route and characterised using X‐ray diffraction, scanning electron microscopy, chemical and thermal analysis, X‐ray absorption and magnetic measurements. These novel pillared layered materials, which were obtained from the monoclinic (P21/c space group) α‐Ti(HPO4)2·H2O phase, lose its crystallinity after intercalation. However all the TM ions are octahedrally surrounded by 6 oxygen atoms, although the X‐ray absorption spectra evidence a clear dependence on the temperature. Surprisingly, all the materials behave as paramagnetic down to 1.5 K, but they exhibit different colours, what means that they are optically active (Co2+: violet; Ni2+: pale green; Fe3+: yellow; Cr3+: dark green).
A Structural Study of the Solid Solution Eu2(Mo1‐xWx)3O12
Authors: Boulahya K. , Parras M. , González‐Calbet J. M. 
Published: August 2005

AbstractA structural study by means of X‐ray and electron diffraction of intermediate oxides between Eu2Mo3O12 and Eu2W3O12 shows the existence of a new Eu2(Mo1−xWx)3O12 solid solution with the scheelite structural type. The essential feature of the x = 1/3 and x = 2/3 compounds is the presence of isolated oxygen tetrahedra, in which, according to X‐ray and electron diffraction data, W and Mo are randomly distributed. Eu atoms occupy distorted square antiprisms sites.
High Dielectric Constant in the Charge‐ordered Manganese Oxide CaMn7O12
Authors: Vilar S. Yáñez , Castro‐Couceiro A. , Rivas‐Murias B. , Fondado A. , Mira J. , Rivas J. , Señarís‐Rodríguez M. A. 
Published: August 2005

AbstractThe dielectric properties of mixed‐oxide CaMn7O12 are reported. This compound exhibits a high dielectric constant at room temperature (ε′r> 104), for frequencies up to 104 Hz, values that make it very attractive for potential applications provided that its rather high losses can be minimized.Complex plane analysis of the obtained data reveal an important extrinsic contribution to these high ε′r values; and also that the intrinsic dielectric constant of this material is ε′r,∞ ≈ 30, a value rather high for this type of compounds, that could be related to the electronic process of charge‐ordering present in this oxide below 440 K.
Grafting of Gold Nanoparticles onto Organogelator‐Templated Fibrous Mercaptosilica
Authors: Llusar Mario , Monrós Guillermo , Pozzo Jean L. , Roux Cécile , Sanchez Clément 
Published: August 2005

AbstractFibrous organosilicas functionalized with mercaptopropyl moieties (20 and 40 Mol‐% of –C3H6SH per Si) have been prepared through a smart, “one‐pot” sol‐gel route employing a phenazinic organogelator (DUOP) as a templating agent. The fibrous mercaptosilicas have been characterized morphologically (SEM observations) and chemically (Raman, 29Si solid‐state NMR and chemical analysis), and the functionality of the final materials have been also confirmed by the efficient post‐grafting of Au nanoparticles. These fibrous gold‐mercaptosilica nanocomposite materials could be very useful for nanoelectronic or optoelectronic applications.
Synthesis and Cytotoxicity of 2‐(2′‐Pyridyl)benzimidazole Complexes of Palladium(II) and Platinum(II)
Authors: Casas José S. , Castiñeiras Alfonso , García‐Martínez Emilia , Parajó Yolanda , Pérez‐Parallé M. Luz , Sánchez‐González Angeles , Sordo José 
Published: August 2005

AbstractCompounds of type [MX2(Hpben)] [M = Pd (X = Cl), Pt (X = Cl, I); Hpben = 2‐(2′‐pyridyl)benzimidazole] were prepared and characterized, and the structures of the Pt derivatives were determined by X‐ray crystallography. The crystals of [PtI2(Hpben)] consist of discrete units in which the Pt atom is coordinated to two iodine atoms and to pyridine and imidazole N atoms in a distorted square planar arrangement. The structure of the chloro derivative is similar, except that the [PtCl2(Hpben)] monomers are hydrogen‐bonded in zig‐zag chains. In assays of the interactions of the Pd and Pt chloro compounds with DNA, and of their in vitro cytotoxic activity against human cervical carcinoma cells (HeLa‐229), human ovarian carcinoma cells (A2780) and a cisplatin‐resistant mutant A2780 line (A2780cis), the only activity observed was modest cytotoxicity of the Pd derivative for A2780.
US Multicultural Pathways
Authors: LEE A. ROBERT 
Published: August 2005

Emily S. Rosenberg, A Date Which Will Live: Pearl Harbor in American Memory (Durham: Duke University Press, 2003, £18.95). Pp. 248. ISBN 0 8223 3206.Greg Robinson, By Order of the President: FDR and the Internment of Japanese Americans (Cambridge, MA: Harvard University Press, 2003, £12.95). Pp. 322. ISBN 0 674 01118 X.Tetsuden Kashima, Judgment without Trial: Japanese American Imprisonment during World War II (Seattle: University of Washington Press, 2003, $35.00). Pp. 336. ISBN 0 295 98299 3.Gerald Early, This Is Where I Came in: Black America in the 1960s (Lincoln, NE: University of Nebraska Press, Abraham Lincoln Lecture Series, 2003, £11. 50). Pp. 144. ISBN 0 80302 1823 0.Deborah Davis Jackson, Our Elders Lived It: American Indian Identity in the City (DeKalb, IL: University of Northern Illinois Press, 2002, $20.00). Pp. 191. ISBN 0 87580 591 4.Yen Le Espiritu, Home Bound: Filipino American Lives across Cultures, Communities, and Countries (Berkeley, Los Angeles and London: University of California Press, 2003, $21.95). Pp. 271. ISBN 0 520 23527 4.Elizabeth Boosahda, Arab-American Faces and Voices: The Origins of an Immigrant Community (Austin: The University of Texas Press, 2003, £18.95). Pp. 288. ISBN 0 292 70919 6.John Kerry, patrician Massachusetts liberal, war hero, and yet dissident from the Vietnam era, vies for the 2004 presidency against George Bush, White House dynastic Republican, self-nominated caring conservative, and yet hard-edged ideologue. Notwithstanding Kerry's Catholicism, or his Jewish family line, both candidates hold sway as heirs to WASP cultural style bolstered by considerable personal fortunes. Howard Dean, New York MD and former Vermont governor, and like Kerry and Bush a Yale graduate, storms the early polls by his activist left-liberal agenda and Internet fundraising. John Edwards, North Carolina senator, personal injuries lawyer, and up-from-the-ranks millionaire, his father a textile factory worker and his mother a postal office employee, conducts a widely agreed good race for the Democratic Party nomination before joining the ticket as would-be Vice President. Had multiculturalism led to any shift of paradigm in connection with canonical whiteness? Or, to put matters more plainly, were not the front-runners once again executive white men, whatever their respective merits or social origins?
Characterization of the ATPase activity of topoisomerase II from Leishmania donovani and identification of residues conferring resistance to etoposide
Authors: Sengupta Tanushri , Mukherjee Mandira , Das Aditi , Mandal Chhabinath , Das Rakhee , Mukherjee Tanmoy , Majumder Hemanta K. 
Published: August 2005

We have cloned and expressed the 43 kDa N-terminal domain of Leishmania donovani topoisomerase II. This protein has an intrinsic ATPase activity and obeys Michaelis–Menten kinetics. Cross-linking studies indicate that the N-terminal domain exists as a dimer both in the presence and absence of nucleotides. Etoposide, an effective antitumour drug, traps eukaryotic DNA topoisomerase II in a covalent complex with DNA. In the present study, we report for the first time that etoposide inhibits the ATPase activity of the recombinant N-terminal domain of L. donovani topoisomerase II. We have modelled the structure of this 43 kDa protein and performed molecular docking analysis with the drug. Mutagenesis of critical amino acids in the vicinity of the ligand-binding pocket reveals less efficient inhibition of the ATPase activity of the enzyme by etoposide. Taken together, these results provide an insight for the development of newer therapeutic agents with specific selectivity.
HIV-1 Nef regulates the release of superoxide anions from human macrophages
Authors: Olivetta Eleonora , Pietraforte Donatella , Schiavoni Ilaria , Minetti Maurizio , Federico Maurizio , Sanchez Massimo 
Published: August 2005

The NADPH oxidase enzymatic complex participates in the oxidative burst by producing ROS (reactive oxygen species). Altered levels of ROS production may have pathogenetic implications due to the loss of some innate immune functions such as oxidative burst and phagocytosis. Considering that HIV-1 Nef protein plays a primary role in AIDS pathogenesis, by affecting the immune system, we sought to dissect possible effects of Nef on the release of superoxide anions. We show here that the inducible expression of Nef in human phagocytic cells modulates the superoxide release in a biphasic manner. In particular, an early Nef-induced increase of the superoxide release was followed by a dramatic decrease starting from 10 h after the Nef induction. This was observed whatever the presence of cell activators such as GM-CSF (granulocyte/macrophage colony-stimulating factor) or fMLP (N-formyl-L-methionyl-L-leucyl-L-phenylalanine). Whereas the early increase in superoxide release is probably the result of the already described Nef-dependent activation of PAK-2 (p21-activated kinase 2)–Rac2, we were interested in investigating the mechanisms underlying the late inhibition of superoxide release observed originally. In this regard, we individuated at least three independent requirements for the Nef-induced blockade of superoxide release: (i) the active protein synthesis; (ii) both the membrane localization and the interaction with endocytotic machinery of Nef; and (iii) the release of soluble factor(s). Moreover, we observed that IL-10 (interleukin-10) inhibits superoxide release, whereas its depletion restored NADPH oxidase activity. We propose that the cell membrane-to-lysosome Nef transit leads to the synthesis and release of soluble factor(s) and, among them, IL-10 might significantly contribute to the inhibition of NAPDH oxidase activity.
Cytoprotection by glycine against ATP-depletion-induced injury is mediated by glycine receptor in renal cells
Authors: Pan Chao , Bai Xiaoming , Fan Leming , Ji Yong , Li Xiaoyu , Chen Qi 
Published: August 2005

It is known that glycine protects mammalian cells against ischaemic cell injury by preventing cellular membrane leakage. However, the molecular mechanisms have not yet been clearly elucidated. The purpose of the present study was to clarify whether GlyR (glycine receptor) acts as a key mediator in cytoprotection of glycine. cDNA encoding human GlyRα1 (α1-subunit of glycine receptor) was transfected into HEK-293 cells. The membrane integrity of the cells with or without GlyRα1 was examined by the uptake of marker compounds, the release of LDH (lactate dehydrogenase) and the exclusion of Trypan Blue. Glycine prevented the permeability of 70 kDa dextrans and 140 kDa LDH in the cells in which GlyR was expressed under conditions of ATP depletion. The inhibition of endogenous GlyR expression by RNA interference attenuated the cytoprotection by glycine. Furthermore, the mutation of Tyr202 to phenylalanine in GlyRα1 blocked the glycine-mediated cytoprotection, while the mutation of Tyr202 to leucine abolished the cytoprotection by strychnine. Our results suggested that the cytoprotection of glycine against ATP-depletion-induced injury might be mediated by GlyR.
Effect of Na+ binding on the conformation, stability and molecular recognition properties of thrombin
Authors: De Filippis Vincenzo , De Dea Elisa , Lucatello Filippo , Frasson Roberta 
Published: August 2005

In the present work, the effect of Na+ binding on the conformational, stability and molecular recognition properties of thrombin was investigated. The binding of Na+ reduces the CD signal in the far-UV region, while increasing the intensity of the near-UV CD and fluorescence spectra. These spectroscopic changes have been assigned to perturbations in the environment of aromatic residues at the level of the S2 and S3 sites, as a result of global rigidification of the thrombin molecule. Indeed, the Na+-bound form is more stable to urea denaturation than the Na+-free form by ∼2 kcal/mol (1 cal≡4.184 J). Notably, the effects of cation binding on thrombin conformation and stability are specific to Na+ and parallel the affinity order of univalent cations for the enzyme. The Na+-bound form is even more resistant to limited proteolysis by subtilisin, at the level of the 148-loop, which is suggestive of the more rigid conformation this segment assumes in the ‘fast’ form. Finally, we have used hirudin fragment 1–47 as a molecular probe of the conformation of thrombin recognition sites in the fast and ‘slow’ form. From the effects of amino acid substitutions on the affinity of fragment 1–47 for the enzyme allosteric forms, we concluded that the specificity sites of thrombin in the Na+-bound form are in a more open and permissible conformation, compared with the more closed structure they assume in the slow form. Taken together, our results indicate that the binding of Na+ to thrombin serves to stabilize the enzyme into a more open and rigid conformation.
A role for tumour necrosis factor α in human small bowel iron transport
Authors: Sharma Naveen , Laftah Abas H. , Brookes Matthew J. , Cooper Brian , Iqbal Tariq , Tselepis Chris 
Published: August 2005

Cytokines are integral to the development of anaemia of chronic inflammation. Cytokines modulate hepcidin expression and iron sequestration by the reticuloendothelial system but their direct effects on small bowel iron transport are not well characterized. The aim of the present study was to examine the local effects of TNFα (tumour necrosis factor α) on small bowel iron transport and on iron transporter expression in the absence of hepcidin. The effects of TNFα on iron transport were determined using radiolabelled iron in an established Caco-2 cell model. The effect of TNFα on the expression and localization of the enterocyte iron transporters DMT-1 (divalent metal transporter 1), IREG-1 (iron-regulated transporter 1) and ferritin was determined utilizing Caco-2 cells and in a human ex vivo small bowel culture system. TNFα mediated an early induction in both iron import and iron export, which were associated with increased DMT-1 and IREG-1 mRNA and protein expression (P&lt;0.05). However, by 24 h, both iron import and iron export were significantly inhibited, coinciding with an induction of ferritin heavy chain (P&lt;0.05) and a decrease in DMT-1 and IREG-1 to baseline levels. In addition, there was a relocalization of IREG-1 away from the basolateral cell border and increased iron deposition in villous enterocytes. In conclusion, TNFα has a direct effect on small bowel iron transporter expression and function, leading to an inhibition of iron transport.
Cloning and characterization of the human glutathione synthetase 5′-flanking region
Authors: Lee Taunia D. , Yang Heping , Whang Janet , Lu Shelly C. 
Published: August 2005

GSH synthesis occurs through a two-step enzymatic reaction driven by GCL (glutamate–cysteine ligase; made up of catalytic and modifying subunits) and GSS (glutathione synthetase). In humans, oxidative stress regulates GCL expression in an antioxidant response element-dependent manner via Nrf2 [NFE (nuclear factor erythroid)-related factor 2]. In the rat, GSS and GCL are regulated co-ordinately by oxidative stress, and induction of GSS further increases GSH synthetic capacity. Transcriptional regulation of the human GSS has not been examined. To address this, we have cloned and characterized a 2.2 kb 5′-flanking region of the human GSS. The transcriptional start site is located 80 nt upstream of the translation start site. The human GSS promoter efficiently drove luciferase expression in Chang cells. Overexpression of either Nrf1 or Nrf2 induced the GSS promoter activity by 130 and 168% respectively. Two regions homologous to the NFE2 motif are demonstrated to be important for basal expression of human GSS, as mutation of these sites reduced the promoter activity by 66%. Nrf1, Nrf2 and c-Jun binding to these NFE2 sites under basal conditions was demonstrated using chromatin immunoprecipitation assays. In summary, two NFE2 sites in the human GSS promoter play important roles in the basal expression of GSS and, similar to the GCL subunits, the human GSS gene expression is also regulated by Nrf2.
Effects of nitroglycerin/L-cysteine on soluble guanylate cyclase: evidence for an activation/inactivation equilibrium controlled by nitric oxide binding and haem oxidation
Authors: Gorren Antonius C. F. , Russwurm Michael , Kollau Alexander , Koesling Doris , Schmidt Kurt , Mayer Bernd 
Published: August 2005

GTN (nitroglycerin; glycerol trinitrate) causes dilation of blood vessels via activation of nitric oxide (NO)-sensitive sGC (soluble guanylate cyclase), a heterodimeric haem protein that catalyses the conversion of GTP into cGMP. Activation of sGC by GTN requires enzymatic or non-enzymatic bioactivation of the nitrate. Based on insufficient NO release and lack of spectroscopic evidence for formation of NO–sGC, the cysteine (Cys)-dependent activation of sGC by GTN was proposed to occur in an NO-independent manner. This extraordinary claim is questioned by the present findings. First, the effect of GTN/Cys was blocked by the NO scavenger oxyhaemoglobin, the superoxide-generating compound flavin mononucleotide and the haem-site sGC inhibitor ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one). Secondly, at equi-effective concentrations, GTN/Cys and the NO donor 2,2-diethyl-1-nitroso-oxyhydrazine released identical amounts of NO. Finally, at sufficiently high rates of NO release, activation of sGC by GTN/Cys was accompanied by a shift of the Soret band from 431 to 399 nm, indicating formation of NO–sGC. In the absence of Cys, GTN caused haem oxidation, apparent as a shift of the Soret band to 392 nm, which was accompanied by inactivation of the NO-stimulated enzyme. These results suggest that the effect of GTN/Cys is the result of an activation/inactivation equilibrium that is controlled by the rate of NO release and haem oxidation.
Role of chirality in peptide-induced formation of cholesterol-rich domains
Authors: Epand Richard M. , Rychnovsky Scott D. , Belani Jitendra D. , Epand Raquel F. 
Published: August 2005

The chiral specificity of the interactions of peptides that induce the formation of cholesterol-rich domains has not been extensively investigated. Both the peptide and most lipids are chiral, so there is a possibility that interactions between peptide and lipid could require chiral recognition. On the other hand, in our models with small peptides, the extent of folding of the peptide to form a specific binding pocket is limited. We have determined that replacing cholesterol with its enantiomer, ent-cholesterol, alters the modulation of lipid organization by peptides. The phase-transition properties of SOPC (1-stearoyl-2-oleoylphosphatidylcholine):cholesterol [in a 6:4 ratio with 0.2 mol% PtdIns(4,5)P2] are not significantly altered when ent-cholesterol replaces cholesterol. However, in the presence of 10 mol% of a 19-amino-acid, N-terminally myristoylated fragment (myristoyl-GGKLSKKKKGYNVNDEKAK-amide) of the protein NAP-22 (neuronal axonal membrane protein), the lipid mixture containing cholesterol undergoes separation into cholesterol-rich and cholesterol-depleted domains. This does not occur when ent-cholesterol replaces cholesterol. In another example, when N-acetyl-Leu-Trp-Tyr-Ile-Lys-amide (N-acetyl-LWYIK-amide) is added to SOPC:cholesterol (7:3 ratio), there is a marked increase in the transition enthalpy of the phospholipid, indicating separation of a cholesterol-depleted domain of SOPC. This phenomenon completely disappears when ent-cholesterol replaces cholesterol. The all-D-isomer of N-acetyl-LWYIK-amide also induces the formation of cholesterol-rich domains with natural cholesterol, but does so to a lesser extent with ent-cholesterol. Thus specific peptide chirality is not required for interaction with cholesterol-containing membranes. However, a specific chirality of membrane lipids is required for peptide-induced formation of cholesterol-rich domains.
Physicochemical analysis of acid–base status during recovery from high-intensity exercise in Standardbred racehorses
Authors: Waller Amanda , Lindinger Michael I 
Published: August 2005

AbstractThe present study used the physicochemical approach to characterize the changes in acid–base status that occur in Standardbred racehorses during recovery from high-intensity exercise. Jugular venous blood was sampled from nine Standardbreds in racing condition, at rest and for 2 h following a high-intensity training workout. Plasma [H+] increased from 39.1±1.0 neq l−1at rest to 44.8±2.7 neq l−1at 1 min of recovery. A decreased strong ion difference ([SID]) was the primary contributor to the increased [H+] immediately at the end of exercise, while increased plasma weak ion concentration ([Atot]) was a minor contributor to the acidosis. A decreased partial pressure of carbon dioxide (PCO2) at 1 min of recovery had a slight alkalinizing effect. The decreased [SID] at 1 min of recovery was a result of a 15.1±3.1 meq l−1increase in [lactate−], as [Na+] and [K+] were also increased by 6.5±0.7 and 1.14±0.06 meq l−1, respectively, at 1 min of recovery. It is concluded that high-intensity exercise and recovery is associated with significant changes in acid–base balance, and that full recovery of many parameters that determine acid–base status requires 60–120 min.