bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Convergent Approach for the Generation of Dendrimers Containing the ­[Ru3O(CH3COO)6] Electroactive Core
Authors: Nikolaou Sofia , Toma Henrique E. 
Published: April 2008

AbstractWe report on a convergent approach for the generation of dendrimers containing the [Ru3O(ac)6] electroactive core, of great interest as multielectron transfer catalysts. The proposed strategy is based on the generation of the trimeric complex [{Ru3O(ac)6(4‐pic)2(pz)}2‐μ2‐Ru3O(ac)6(CH3OH)]3+ (ac = acetate, 4‐pic = 4‐methylpyridine, pz = pyrazine). In this complex, the labile CH3OH ligand can be displaced by the bridging pyrazine ligand of [Ru3O(ac)6(pz)3]0, leading to the self‐assembly of the [{[Ru3O(ac)6(4‐pic)2(pz)]2‐μ2‐Ru3O(ac)6(pz)}3‐μ3‐Ru3O(ac)6]n+ dendrimer containing 30 ruthenium atoms.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Silylene and Germylene Intermediates in the Reactions of Silole and Germole Dianions with N,N′‐Di‐tert‐butylethylenediimine
Authors: Toulokhonova Irina S. , Timokhin Vitaly I. , Bunck David N. , Guzei Ilia , West Robert , Müller Thomas 
Published: April 2008

AbstractSpiro‐diazasilole (germole) adducts were observed in reactions of dilithium salts of silole and germole dianions with N,N′‐di‐tert‐butylethylenediimine in THF at room temperature. A proposed mechanism of the reaction includes metallation of N,N′‐di‐tert‐butylethylenediimine and the formation of an intermediate silylene or germylene. This reaction mechanism was supported by experimental data and theoretical calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Thermodynamic Study of σH Complexes in Nucleophilic Aromatic Substitution Reactions: Relative Stabilities of Electrochemically Generated Radicals
Authors: Gallardo Iluminada , Guirado Gonzalo 
Published: April 2008

AbstractThe mechanism for the electrochemical oxidation of σH complexes, such as 1‐hydro‐1‐alkoxy/sulfoxy or ‐fluoro‐2,4‐dinitro/2,4,6‐trinitrocyclohexadienyl anions, has been widely studied by means of cyclic voltammetry and controlled‐potential electrolysis. Previous studies have shown that the electrochemical oxidation of σH complexes, formed by the addition of carbon or nitrogen nucleophiles followed by a two electron mechanism, corresponding to the formal elimination of the hydride anion (nucleophilic aromatic substitution of hydrogen mechanism, the NASH mechanism). For these σH complexes (Nu– = OH–, –OR, –SR, –F), the electrochemical reaction takes place by a one‐electron mechanism and is followed by the radical elimination of the leaving group with the consequent recovery of the starting material. This mechanism is similar to that proposed for the electrochemical oxidation of σX complexes (nucleophilic aromatic substitution of a heteroatom, the NASX mechanism). The operating mechanism in each case, the NASH or NASX, can be rationalized in terms of thermodynamics. The standard potentials of the σ complex and/or the leaving group as well as the bond dissociation energies (BDEs) are determinant factors. This study has not led to a significant improvement in the electrochemical preparation of aromatic‐substituted compounds, but does help to understand and predict the usefulness or uselessness of using the nucleophilic aromatic substitution route to obtain a desired product. Finally, the current approach extends the electrochemical methodology to different chemical fields, for example, to general nondestructive methods for the detection, identification, and quantification of either organic pollutants or explosives in different solvents. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Applications of Chiral Ionic Liquids
Authors: Bica Katharina , Gaertner Peter 
Published: April 2008

AbstractDespite the rapid growth in chiral ionic liquid (CIL) research, successful applications remained hidden for some time, but are increasing fast nowadays. The major part of this review deals with the use of CILs as solvents, catalysts or ligands in asymmetric synthesis. Chiral recognition abilities in spectroscopic techniques such as NMR, NIR or fluorescence spectroscopy are discussed as well as the application of CILs for separation in chromatography. In this review, we focus entirely on the applications of CILs; publications dealing with design and synthesis of CILs only are not mentioned. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Photosensitized Electron Transfer Oxidation of Sulfides: A Steady‐State Study
Authors: Bonesi Sergio M. , Fagnoni Maurizio , Albini Angelo 
Published: April 2008

AbstractThe photosensitized electron‐transfer oxidation of a series of ethyl sulfides RSEt (1, R = C12H25; 2, PhCH2CH2; 3, PhCH2; 4, PhCMe2; 5, Ph2CH) has been examined in acetonitrile and the product distribution discussed on the basis of the mechanisms proposed. In nitrogen‐flushed solutions, cleaved alcohols and alkenes are formed, whereas under oxygen, in reactions that are 10–70 times faster, sulfoxides and cleaved aldehydes and ketones are formed in addition to the aforementioned products. Two sensitizers are compared, 9,10‐dicyanoanthracene (DCA) and 2,4,6‐triphenylpyrylium tetrafluoroborate (TPP+BF4–), the former giving a higher proportion of the sulfoxide, the latter of cleaved carbonyls. The sulfoxidation is due to the contribution of the singlet oxygen path with DCA. Oxidative cleavage, on the other hand, occurs both with DCA and with TPP+ which is known to produce neither singlet oxygen nor the superoxide anion. This process involves deprotonation from the α position of the sulfide radical cation, but the TPP+ results suggest that O2·– is not necessarily involved and non‐activated oxygen forms a weak adduct with the radical cation promoting α‐hydrogen transfer, particularly with benzylic derivatives.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Highly Stereoselective Metal‐Mediated Entry to Functionalized Tetrahydrothiophenes by Barbier‐Type Carbonyl‐Addition Reactions
Authors: Alcaide Benito , Almendros Pedro , Martínez del Campo Teresa 
Published: April 2008

AbstractReactions of tetrahydrothiophene‐3‐carbaldehydes with stabilized organometallic reagents were investigated in aqueous media. Tetrahydrothiophene‐3‐carbaldehydes and a variety of stabilized organic halides undergo stereocontrolled coupling under Barbier‐type conditions in the presence of different metals (zinc, tin, indium) and additives [ammonium chloride, hydrobromic acid, hafnium(IV) chloride, bismuth(III) chloride]. The regiochemistry of the carbonyl addition processes, when applicable, was excellent.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Parametric study of ductile moment‐resisting steel frames: A first step towards Eurocode 8 calibration
Authors: Sanchez‐Ricart L. , Plumier A. 
Published: April 2008

AbstractA parametric study of 13 608 ductile moment‐resisting steel frames designed according to Eurocodes 3 and 8 is performed. A flowchart for the evaluation of the seismic‐resistant capacity of the designed frames is developed based on the N2 method. The design structural overstrength, ductility supply, plastic redistribution parameter, supply reduction factor and performance ratio of the frames are analysed. We determine that the frames have performance ratios higher than 1, mostly due to high values of design structural overstrength, showing that the seismic supply produced by the restraints of Eurocodes 3 and 8 is always higher than the seismic demand. Copyright © 2008 John Wiley & Sons, Ltd.
Human cytomegalovirus load measurement and its applications for pre‐emptive therapy in patients undergoing hematopoietic stem cell transplantation
Authors: Baldanti Fausto , Lilleri Daniele , Gerna Giuseppe 
Published: April 2008

AbstractThe hematopoietic stem cell transplantation (HSCT) setting is a rapidly evolving field, and procedures with a high degree of complexity are now entering into the clinic. The risk of developing opportunistic viral infections increases with the level of human leukocyte antigen disparity between the donor and the recipient of allogeneic HSCT and is enhanced by graft manipulations such as T‐cell depletion or immune suppression required to control graft versus host disease (GVHD) or rejection. Among the opportunistic viral infections potentially hampering the outcome of HSCT, human cytomegalovirus (HCMV) infection plays a major role. In the early 1980s, before the introduction of effective antiviral treatment, HCMV disease accounted for the high mortality in recipients of allogeneic HSCT. In more recent years, the availability of HCMV‐specific antiviral agents (ganciclovir, GCV, foscarnet, PFA and cidofovir, CDV) led to a dramatic decrease in HCMV‐related morbidity and mortality. However, HCMV infection still remains a major concern in the HSCT setting. Historically, treatment of HCMV infection in HSCT recipients (HSCTR) evolved from treatment of overt HCMV disease to universal prophylaxis or pre‐emptive treatment of active infection, in parallel with the improvement of techniques for diagnosing and monitoring HCMV infection in transplant recipients. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of bearing size on the long‐term wear, wear debris, and ion levels of large diameter metal‐on‐metal hip replacements—An in vitro study
Authors: Leslie Ian , Williams Sophie , Brown Chris , Isaac Graham , Jin Zhongmin , Ingham Eileen , Fisher John 
Published: April 2008

AbstractHip resurfacing arthroplasty has become a popular alternative to conventional hip surgery. Surface replacements with bearing sizes of 55 mm (n = 5) and 39 mm (n = 5) were tested in a hip simulator for 15 million cycles (Mc). Wear debris was isolated from the serum lubricant and characterized by field emmitting gun scanning electorn microscopy, and ion levels were measured via inductively coupled plasma mass spectroscopy at intervals throughout the test. The 39 mm bearings showed significantly greater bedding in volumetric wear (2.58 mm3) compared with the 55 mm bearings (1.15 mm3). There was no significant difference between the steady state wear rates (1–15 Mc) between the two sizes (0.10 and 0.09 mm3/Mc, respectively); however, this parity only became clear after 7 Mc. The wear debris isolated was oval in morphology with a mean particle size of 28 nm and a range of 9–108 nm. The Co levels measured at 0.13 Mc were significantly greater than at 3.6 Mc for both bearing sizes (10926 ppb and 176 ppb, respectively). After 0.5 Mc, the Co levels from the 39 mm bearings were significantly higher than the 55 mm (11,007 vs. 1475 ppb). The wear results support previous findings showing that increasing the femoral head size decreased volumetric bedding in wear. The ion levels measured suggest both bearing sizes have similar initial wear rates; however, the 55 mm bearings reach steady state wear more rapidly. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
Alternative splicing of Nav1.5: An electrophysiological comparison of ‘neonatal’ and ‘adult’ isoforms and critical involvement of a lysine residue
Authors: Onkal Rustem , Mattis Joanna H. , Fraser Scott P. , Diss James K.J. , Shao Dongmin , Okuse Kenji , Djamgoz Mustafa B.A. 
Published: April 2008

AbstractIn developmentally regulated D1:S3 splicing of Nav1.5, there are 31 nucleotide differences between the 5′‐exon (‘neonatal’) and the 3′‐exon (‘adult’) forms, resulting in 7 amino acid differences in D1:S3‐S3/S4 linker. In particular, splicing replaces a conserved negative aspartate residue in the ‘adult’ with a positive lysine. Here, ‘neonatal’ and ‘adult’ Nav1.5 α‐subunit splice variants were stably transfected into EBNA‐293 cells and their electrophysiological properties investigated by whole‐cell patch‐clamp recording. Compared with the ‘adult’ isoform, the ‘neonatal’ channel exhibited (1) a depolarized threshold of activation and voltage at which the current peaked; (2) much slower kinetics of activation and inactivation; (3) 50% greater transient charge (Na+) influx; (4) a stronger voltage dependence of time to peak; and (5) a slower recovery from inactivation. Tetrodotoxin sensitivity and VGSCβ1‐4 mRNA expression levels did not change. The significance of the charge‐reversing aspartate to lysine substitution was investigated by mutating the lysine in the ‘neonatal’ channel back to aspartate. In this ‘neonatal K211D’ mutant, the electrophysiological parameters studied strongly shifted back towards the ‘adult’, that is the lysine residue was primarily responsible for the electrophysiological effects of Nav1.5 D1:S3 splicing. Taken together, these data suggest that the charge reversal in ‘neonatal’ Nav1.5 would (1) modify the channel kinetics and (2) prolong the resultant current, allowing greater intracellular Na+ influx. Developmental and pathophysiological consequences of such differences are discussed. J. Cell. Physiol. 216: 716–726, 2008, © 2008 Wiley‐Liss, Inc.
Altered expression of endoplasmic reticulum aminopeptidases ERAP1 and ERAP2 in transformed non‐lymphoid human tissues
Authors: Fruci Doriana , Giacomini Patrizio , Nicotra Maria R. , Forloni Matteo , Fraioli Rocco , Saveanu Loredana , van Endert Peter , Natali Pier Giorgio 
Published: April 2008

AbstractThe endoplasmic reticulum (ER) aminopeptidases ERAP1 and ERAP2 contribute to generate HLA class I binding peptides. Recently, we have shown that the expression of these enzymes is high and coordinated (with each other and with HLA class I molecules) in immortalized B cells, but variable and imbalanced in human tumour cell lines of various non‐lymphoid lineages. Herein, this issue was investigated in vivo by testing ERAP1 and ERAP2 expression in normal non‐lymphoid tissues and their malignant counterparts. ERAP1 and ERAP2 were detected exclusively in the epithelial cells of over half of the tested normal tissues. Four ERAP1/ERAP2 phenotypes (+/+, −/−, +/− and −/+) were detected, and the presence of either or both enzymes was not necessarily associated with HLA class I expression. In more than 160 neoplastic lesions, the expression of either or both aminopeptidases was retained, lost (most frequently, particularly ERAP1) or acquired as compared to the normal counterparts, depending on the tumour histotype. The double‐negative (−/−) phenotype was the most frequent, and significantly (P = 0.013) associated with a lack of detectable HLA class I antigens. In selected neoplastic lesions, ERAP1 and ERAP2 were also tested for their enzymatic (peptide‐trimming) activities. Expression and function were found to correlate, indicating that immunohistochemistry detects active enzymes in vivo. Thus, dissociation in the expression of ERAP1, ERAP2 and HLA class I may already be present in some normal tissues, but malignant transformation causes additional losses, gains and imbalances in specific tumour histotypes, and these alter the peptide‐trimming ability of tumour cells in vivo. J. Cell. Physiol. 216: 742–749, 2008, © 2008 Wiley‐Liss, Inc.
Structure and function of 2:1 DNA polymerase·DNA complexes
Authors: Tang Kuo‐Hsiang , Tsai Ming‐Daw 
Published: April 2008

AbstractDNA polymerases are required for DNA replication and DNA repair in all of the living organisms. Different DNA polymerases are responsible different stages of DNA metabolism, and many of them are multifunctional enzymes. It was generally assumed that the different reactions are catalyzed by the same enzyme molecule. In addition to 1:1 DNA polymerase·DNA complex reported by crystallization studies, 2:1 and higher order DNA polymerase·DNA complexes have been identified in solution studies by various biochemical and biophysical approaches. Further, abundant evidences for the DNA polymerase–DNA interactions in several DNA polymerases suggested that the 2:1 complex represents the more active form. This review describes the current status of this emerging subject and explores their potential in vitro and in vivo functional significance, particularly for the 2:1 complexes of mammalian DNA polymerase β (Pol β), the Klenow fragment of E. coli DNA polymerase I (KF), and T4 DNA polymerase. J. Cell. Physiol. 216: 315–320, 2008. © 2008 Wiley‐Liss, Inc.
Membrane‐assisted vapor stripping: energy efficient hybrid distillation–vapor permeation process for alcohol–water separation
Authors: Vane Leland M , Alvarez Franklin R 
Published: April 2008

AbstractBACKGROUND: Energy efficient alternatives to distillation for alcohol recovery from dilute solution are needed to improve biofuel sustainability. A process integrating steam stripping with a vapor compression step and a vapor permeation membrane separation step is proposed. The objective of this work is to estimate the energy and process costs required to make a fuel grade ethanol (0.5 wt% water) from 1 and 5 wt% ethanol aqueous streams using the proposed process.RESULTS: Using process simulation and spreadsheeting software, the proposed membrane‐assisted vapor stripping process was estimated to require as little as 8.9 MJ of fuel‐equivalent energy per kg of fuel grade ethanol recovered from a 1 wt% ethanol feed stream, 2.5 MJ kg−1 for a 5 wt% ethanol solution. This represents an energy saving of at least 43% relative to standard distillation producing azeotropic ethanol (6 wt% water). Process costs were also found to be lower than for distillation at the 3.0 × 106 kg‐ethanol year−1 scale modeled.CONCLUSION: In this hybrid system, the stripping column provides high ethanol recoveries and low effluent concentrations while the vapor compression‐membrane component enables the efficient recovery of latent and sensible heat from both the retentate and permeate streams from the membrane system. Published in 2008 by John Wiley & Sons, Ltd.
Purification and characterization of an organic solvent and detergent‐tolerant novel protease produced by Bacillus sp. RKY3
Authors: Reddy LVA , Wee Young‐Jung , Ryu Hwa‐Won 
Published: April 2008

AbstractBACKGROUND: Purification and characterization of a novel protease produced by Bacillus sp. RKY3, has been investigated, with special emphasis on the stability of the enzyme in the presence of different oxidizing and reducing agents as well as organic solvents. The enzyme was purified in two steps through concentration of the crude enzyme by ammonium sulfate precipitation, followed by anion exchange chromatography.RESULTS: The purified protease had a molecular mass of approximately 38 kDa, which was highly active over a broad range of pH between 7.0 and 9.0 and was also stable over a wide pH range from 5.0 to 11.0. Although the optimum temperature for enzyme activity was found to be 60 °C, it was rapidly deactivated at temperatures above 60 °C. It also showed good stability at 50 °C, with a 70 min half‐life. Ca2+ ions did not greatly enhance the activity or the stability of the enzyme. PMSF (1 mmol L−1) completely inhibited the protease activity, and thus the purified protease was considered to be serine protease. The purified protease was stable with oxidants (H2O2, 2%), reducing agents (sodium dodecyl sulfate, 2%), and organic solvents (25%) such as benzene, hexane, and toluene.CONCLUSION: The purified enzyme, protease, seems to possess potential applications in protease‐based detergent and bleaching industries. The enzymatic activity against a wide variety of substrates suggests that the purified enzyme should be investigated for a range of commercial applications, especially for soy protein and gelatin hydrolysis in the food processing industry. Copyright © 2008 Society of Chemical Industry
Transneuronal retrograde viral labeling in the brain stem and hypothalamus is more intense from the left than from the right adrenal gland
Authors: Tóth Ida E. , Wiesel Ory , Tóth Dorina E. , Boldogkői Zsolt , Halász Béla , Gerendai Ida 
Published: April 2008

AbstractPrevious studies using the viral transneuronal tracing technique demonstrated central autonomic circuits involved in the innervation of the adrenal gland. Since increasing number of data indicate laterality in the neuroendocrine system, we aimed to investigate whether the supraspinal innervation of the adrenal gland exhibits asymmetry or not. The central circuitry involved in the innervation of the left and the right adrenal gland was studied in individual rats by dual transneuronal tracing using isogenic recombinant strains (Ba‐DupGreen and Ba‐Duplac expressing lacZ) of Bartha strain of pseudorabies virus. Viral infection of brain nuclei (dorsal vagal nucleus, nucleus of the solitary tract, caudal raphe nuclei, A5 cell group, hypothalamic paraventricular nucleus) from the left adrenal was more severe than that from the right organ. Dual‐infected neurons were present both in the brain stem and in the hypothalamus. The results indicate a predominance in the supraspinal innervation of the left adrenal gland, and that each adrenal gland is innervated both by side‐specific neurons and by neurons that project to both organs. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Effect of elevated nitrogen levels on endogenous gibberellin and jasmonic acid contents of three rice (Oryza sativa L.) cultivars
Authors: Jang Soo‐Won , Hamayun Muhammad , Sohn Eun‐Young , Shin Dong‐Hyun , Kim Kil‐Ung , Lee Byung‐Hyun , Lee In‐Jung 
Published: April 2008

AbstractThree rice (Oryza sativa L.) cultivars ( cv. Daesanbyeo, cv. Dongjinbyeo, cv. Junambyeo) were analyzed for endogenous gibberellin (GA) and jasmonic acid (JA) contents and their changes in response to elevated nitrogen (N) levels. The N fertilizer was applied in the form of urea [(NH2)2CO] at three rates (0, 36.8, 73.6 kg N ha–1). Plant growth (height and dry weight) was enhanced by the first N rate but not further enhanced by the highest rate. The endogenous GA contents were analyzed through high‐performance liquid chromatography (HPLC) and gas chromatography–mass spectrometry–selected ion monitoring (GC‐MS‐SIM) while that of JA with GC‐MS‐SIM. They were analyzed one week after N application and were significantly increased with elevated N levels in all rice cultivars. The bioactive GA1 markedly increased, but its concentration differed in different rice cultivars. Similar fluctuations were observed for endogenous GA8, GA12, GA19, GA20, and GA53 in response to elevated N levels, showing that the rates of biosynthesis of GAs were differently affected by elevated N levels within different rice cultivars. The level of GA20, a precursor of GA1 biosynthesis, was not significantly increased, though GA19, a precursor of GA20, was found to be the most abundant GA type in all rice cultivars. Jasmonic acid content in the plants increased with the basic urea application (36.8 kg N ha–1), but significantly decreased with the double urea level (73.6 kg N ha–1). The results demonstrate that GA and JA are differentially affected in response to elevated N application in rice.