bluuebunny/crossref_metadata_2025 huggingface dataset:
C1‐Symmetric Diphosphite Ligands Derived from Carbohydrates: Influence of Structural Modifications on the Rhodium‐Catalyzed Asymmetric Hydroformylation of Styrene
Authors: Gual Aitor , Godard Cyril , Claver Carmen , Castillón Sergio
Published: January 2009

New 3,5‐diphosphite‐substituted xylofuranoside (1b, 25a,b, and 26a,b) and glucofuranoside (3a, 7a, 8a,b) ligands with C1 symmetry have been prepared and used in the Rh‐catalyzed asymmetric hydroformylation of styrene. The main structural features of these ligands are a) the presence of a 6‐O‐isopropyl group in ligands with a gluco configuration, b) the absence of 1,2‐O‐isopropylidene, a common group in many ligands with a furanoside skeleton, c) the presence of an alkyl chain bound to the 2‐OH, and d) modification of the diol in the phosphite moiety. Modification of the carbohydrate backbone and diphosphite bridge affects the activity and selectivity of the reaction. Catalytic systems with ligands 1b and 8b were not active at 40 °C, although the formation of the expected hydride species [RhH(CO)2(1b)] was demonstrated by NMR spectroscopy. The highest enantioselectivity (83 %) was obtained with the catalytic system Rh/8a. The complex [RhH(CO)2(8a)] was characterized by NMR spectroscopy using high‐pressure techniques and was shown to exist in solution as two isomers in equilibrium; the two isomers adopt an equatorial–equatorial (eq–eq) configuration. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Iron‐Catalyzed One‐Pot Oxidative Esterification of Aldehydes
Authors: Wu Xiao‐Feng , Darcel Christophe
Published: January 2009

A highly efficient, mild, and simple protocol for Fe(ClO4)3·xH2O‐catalyzed oxidative esterification of aldehydes was developed. Several aromatic and aliphatic aldehydes reacted with simple primary and secondary alcohols, used as the solvent, smoothly in the presence of an iron salt catalyst (10 mol‐%) and hydroperoxide (4 equiv.) as an oxidant to generate the corresponding esters in good to excellent yields.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Cycloaddition Reactions of 1‐Alkyl‐3,4,5‐triphenyl‐1,2‐diphosphacyclopenta‐2,4‐dienes
Authors: Miluykov Vasili , Bezkishko Ilya , Zagidullin Almaz , Sinyashin Oleg , Lönnecke Peter , Hey‐Hawkins Evamarie
Published: January 2009

1‐Alkyl‐3,4,5‐triphenyl‐1,2‐diphosphacyclopenta‐2,4‐dienes 1, obtained by alkylation of sodium 1,2‐diphospha‐3,4,5‐triphenylcyclopentadienide, exhibit dual reactivity in cycloaddition reactions: as dienes (with maleic anhydride and maleimide) or as dienophiles (with 2,3‐dimethylbutadiene). Thermolysis of 1 occurs with a [1,5] sigmatropic shift to form a [2+2] cyclodimerization product.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
B(OMe)3 as a Nonacidic Iminium Ion Generator in Mannich‐ and Ugi‐Type Reactions
Authors: Tanaka Yusuke , Hidaka Kousuke , Hasui Tomoaki , Suginome Michinori
Published: January 2009

Mannich‐type reactions of aldehydes with secondary amines and a ketene silyl acetal were promoted by trimethoxyborane in DMSO to afford the corresponding β‐amino esters in good yields. B(OMe)3 also promoted Ugi‐type reactions ofaldehydes with secondary amines and isocyanides in 1,2‐dichloroethane, which leads to the formation of α‐amino amides. In these reactions, trimethoxyborane serves as an inexpensive, commercially available, and virtually nonacidic iminium ion generator.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Organocatalytic Asymmetric Sulfa‐Michael Additions to α,β‐Unsaturated Sulfonates
Authors: Enders Dieter , Hoffman Krzysztof
Published: January 2009

The reactivity of α,β‐unsaturated sulfonates and aromaticthiols in an organocatalyzed sulfa‐Michael addition was explored. Bifunctional chiral thiourea catalysts were found to promote the reaction, and the corresponding Michael adducts were afforded in moderate to good yields (24–92 %) and with moderate levels of asymmetric induction (33–64 % ee). This study represents the first use of α,β‐unsaturated sulfonates in a catalytic asymmetric Michael addition. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Electrochemical Investigation of Strontium–Metallothionein Interactions – Analysis of Serum and Urine of Patients with Osteoporosis
Authors: Fabrik Ivo , Kukacka Jiri , Baloun Jiri , Sotornik Ivo , Adam Vojtech , Prusa Richard , Vajtr David , Babula Petr , Kizek Rene
Published: January 2009

The main aim of this paper is to study interaction between strontium and metallothionein (MT), and to determine changes in strontium and thiols (MT, reduced glutathione, cysteine, and homocysteine) level in plasma, serum, and urine samples of patients treated with strontium ranelate (SrR). To investigate the interactions between MT and strontium(II) ions, adsorptive transfer stripping technique coupled with differential pulse voltammetry (DPV) the Brdicka reaction was employed. Besides standard Brdicka signals (Co, RS2Co, Cat1, Cat2, Cat3), we observed new signal related to Sr‐MT interaction. Further we investigated the effect of various time of interaction, concentration of strontium(II) ions and temperature of supporting electrolyte on Brdicka signals. Optimal time of interaction was 240 s. Under temperature of supporting electrolyte 20 °C, we measured linear dependence of Cat3 signal height on strontium(II) ions concentration. After that we have investigated the possibility of strontium‐MT interactions, we were interested in strontium, MT and low molecular mass thiols levels in serum and urine of patients treated with strontium(II) ions to cure osteoporosis. Strontium concentration determined by atomic absorption spectrometry was 55±5 μg/L before and 10,500±1,400 μg/L at the 30thday of SrR administration. Levels of metallothionein in serum ranged from 0.1 to 6.4 μM. Correlation between serum strontium concentration and MT level was determined and correlation coefficient wasR=0.93.
MTBITC mediates cell cycle arrest and apoptosis induction in human HepG2 cells despite its rapid degradation kinetics in the in vitro model
Authors: Lamy Evelyn , Mersch‐Sundermann Volker
Published: January 2009

Despite the great variety of structure homologous, experimental research on the cancer preventive properties of isothiocyanates (ITCs) is limited to only a fractional amount thereof so far. Especially the degradation of these compounds in the experimental system has not been investigated so far. In this study, we investigated the effect of 4‐methylthiobutyl isothiocyante (MTBITC) on the proliferation of human hepatoma (HepG2) cells and underlying mechanisms. A concentration and time‐dependent reduction in proliferation activity could be observed in cells treated with MTBITC exceeding 10 μM. At these concentrations MTBITC‐induced apoptosis in HepG2 cells could be observed by internucleosomal DNA fragmentation, flow cytometry analysis, and the detection of single‐stranded apoptotic DNA. In all the three assays, clear apoptotic events were present after 6‐hr exposure to MTBITC. Apoptosis induction was accompanied by a time‐dependent arrest of HepG2 cells at the G2/M phase of the cell cycle. This study shows for the first time the inhibitory potency of MTBITC on metabolically competent hepatoma cells, whereas the loss of reduced glutathione and its impact on mitochondria seem to be the major processes involved in the initiation and execution of the apoptotic cell death. The results of this study also showed that irrespective of the intense degradation kinetics of MTBITC, the strong cytostatic effect of the ITC was not markedly affected by it and suggests that although ITCs are only present at maximum concentrations in a living system for a rather short time, this might be sufficient to exert their therapeutic effects. Environ. Mal. Mutagen. 2009. © 2009 Wiley‐Liss, Inc.
Thiiranation of 2′‐adamantylidene‐9‐benzonorbornenylidene using 4,4′‐oligothiodimorpholine and brønsted acid
Authors: Sugihara Yoshiaki , Nozumi Hiroko , Nakayama Juzo
Published: January 2009

On leaving 4,4′‐dithiodimorpholine 6 powder undisturbed at room temperature over 10 years, it led to the formation of 4,4′‐tetrathiodimorpholine 7. Reactions of 2′‐adamantylidene‐9‐benzonorbornenyidene 1 with 6, 7, and 4,4′‐thiodimorpholine 8 and a Brønsted acid in CH2Cl2 at room temperature proceeded to afford the corresponding thiiranes, 2 and 3. The order of reactivity of 4,4′‐oligothiodimorpholines combined with a Brønsted acid is 7 > 6 > 8. The thiirane 3 was transformed to 1 and 2 under the reaction conditions. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:12–18, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20505
Syntheses and crystal structures of triorganotin (IV) derivatives with 2,2′‐bipyridine‐4,4′‐dicarboxylic acid
Authors: Zhang Ru‐Fen , Li Qian‐Li , Ma Chun‐Lin
Published: January 2009

Four organotin complexes with 2,2′‐bipyridine‐4,4′‐dicarboxylic acid, H2dcbp: (Ph3n)2(dcbp) 1, [(PhCH2)3n]2(dcbp) ⋅ 2CH3OH 2, [(Me3Sn)2(dcbp)]n 3, [(Bu3Sn)2(dcbp)]n 4 have been synthesized. The complexes 1–4 were characterized by elemental, IR, 1H, 13C, 119n NMR, and X‐ray crystallographic analyses. Crystal structures show that complex 1 is a monomer with one ligand coordinated to two triorganotin moieties, and a 1D infinite polymeric chain generates via intermolecular CH⋅⋅⋅N hydrogen bond; complex 2 is also a monomer and forms a 2D network by intermolecular O–H⋅⋅⋅O weak interaction; both of complexes 3 and 4 form 2D network structures where 2,2′‐bipyridine‐4,4′‐dicarboxylate acts as a tetradentate ligand coordinated to trimethyltin and tri‐n‐butyltin ions, respectively. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:19–28, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20506
Reactions of 9,9′‐bibenzonorbornenylidene sulfoxides with TMSOTf: Anomalous pinacol‐type rearrangement of thiirane 1‐Oxides
Authors: Sugihara Yoshiaki , Yamanaka Shuich , Nakayama Juzo
Published: January 2009

syn‐9,9′‐Bibenzonorbornenylidene sulfoxide 8b underwent pinacol‐type rearrangement to form 9, together with a mixture of thiiranes 4a and 4b by reaction with TMSOTf in CH2Cl2 at room temperature. The rearrangement of anti‐sulfoxide 8a proceeded more slowly giving a mixture of 9, 4a, and 4b. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:29–34, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20507
Preparation and crystal structures of two salts with the 5‐nitrotetrazolate anion
Authors: Klapötke Thomas M. , Sabaté Carles Miró , Welch Jan M.
Published: January 2009

Tetraphenylphosphonium 5‐nitrotetrazolate (2) was prepared by metathesis of sodium 5‐nitrotetrazolate dihydrate (1; NaNT) with tetraphenylphosphonium chloride in acetone. The new compound was fully characterized by vibrational (IR, Raman) and NMR (1H, 13C, and 14N) spectroscopies, elemental analysis, and mass spectrometry. Attempted synthesis of 2‐methyl‐5‐nitrotetrazole (2‐MeNT) by methylation of 1 with dimethylsulfate at reflux from acetonitrile failed, and crystals of an explosive compound with the formula (NaNT)2(H2O)2CH3CN (3), NT = 5‐nitrotetrazolate, formed. X‐ray diffraction techniques were used to determine the crystal structure of 2 and 3. Compound 2 crystallizes in the orthorhombic space group P212121 with four molecules in the unit cell and unit cell parameters a = 7.7413(4) Å, b = 13.624(1) Å, c = 21.252(1) Å, and V = 2241.5(2) Å3, whereas 3 crystallizes in the orthorhombic space group Ama2 with four formula unit in the unit cell and unit cell parameters a = 14.805(6) Å, b = 9.908(4) Å, c = 8.940(3) Å, and V = 1311.4(1) Å3. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:35–44, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20509
Hexacoordinated spirocyclic germanium(IV) complex: Synthesis and structural characterization
Authors: González‐Montiel Simplicio , Cea‐Olivares Raymundo , Jancik Vojtech , Pineda Leslie W. , Toscano Rubén A.
Published: January 2009

The spiro‐dibenzogermocine [O(o‐C6H4S)2]2Ge (1) was prepared in a reaction between O(o‐C6H4SH)2 and Ge(OiPr)4, and its molecular structure was determined by X‐ray diffraction studies. In the solid state, 1 shows the existence of two weak O → Ge transannular interactions, resulting in a hexacoordinated germanium atom that displays the geometry of a distorted bicapped tetrahedron. © 2009 Wiley Periodicals, Inc. Heteroatom Chem 20:45–49, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20510
Career and international assignment fit: Toward an integrative model of success
Authors: Cerdin Jean‐Luc , Pargneux Marie Le
Published: January 2009

This article examines how the fit between career and international assignment is likely to affect the success of the international assignment (IA) at its various stages. We propose an integrative model of IA success that encompasses three stages: pre‐expatriation, expatriation, and repatriation. The main objective of this article is to contribute to the understanding of how individuals' career characteristics infl uence IA success during expatriation and repatriation. In our model, IA success is considered from both the individual and organizational perspective. In addition to drawing on the theory of fit to examine IA success during the expatriation and repatriation stages, we also use human capital and signal theory to examine the relationship between expatriation success and repatriation success. The propositions of our conceptual research provide practical and theoretical implications. © 2009 Wiley Periodicals, Inc.
The influence of expatriate and repatriate experiences on career advancement and repatriate retention
Authors: Kraimer Maria L. , Shaffer Margaret A. , Bolino Mark C.
Published: January 2009

We address repatriate retention from a career advancement perspective by developing a model that analyzes the effect of expatriate experiences and organizational career support on repatriates' career advancement upon return to the home country. Career advancement, in turn, is expected to affect the repatriate's perceived underemployment and turnover intentions. We collected data from a sample of 84 recently repatriated employees. Results revealed a curvilinear relationship between the number of international assignments and career advancement upon repatriation. Results also showed that developmental expatriate assignments were positively related to career advancement while the acquisition of managerial skills was negatively related to career advancement. Acquiring cultural skills, completing assignment objectives, and organizational career support did not relate to career advancement. In terms of outcomes, we found that perceived underemployment mediated the relationship between career advancement and turnover intentions. A lower level of organizational career support also resulted in greater turnover intentions. © 2009 Wiley Periodicals, Inc.
Problem‐focused versus emotion‐focused coping strategies and repatriation adjustment
Authors: Herman Jeffrey L. , Tetrick Lois E.
Published: January 2009

Failure to cope with a stressful repatriation transition can derail the global career experience. Repatriate stress‐coping behaviors have not been examined empirically, however. This study explores the factor structure of an extensive array of coping strategies and their relation with repatriate adjustment. Data collected from 282 repatriates involved in a boundaryless repatriation experience reveal a factor structure consistent with problem‐ and emotion‐focused dimensions documented elsewhere. Regression analysis finds negative associations between emotion‐focused coping strategies and repatriate general, interaction, and work adjustment and positive relations between problem‐focused strategies and repatriate interaction and work adjustment. © 2009 Wiley Periodicals, Inc.
Expatriation outside the boundaries of the multinational corporation: A study with expatriate nurses in Saudi Arabia
Authors: Bozionelos Nikos
Published: January 2009

To date, research has largely neglected individuals who become expatriates on their own initiative and outside the boundaries of multinational corporations. This study, which focused on 206 non‐Saudi expatriate nurses employed in a Saudi Arabian hospital, investigated the relationship of job satisfaction and turnover intentions with four factors: cross‐cultural training, protégé experience, peer support, and the cultural clusters of the home and host countries. The study also examined the role of gender in the relationship of work attitudes with protégé experience and peer support. Protégé experience had the most consistent relationship with job satisfaction and turnover intentions, while attendance of cross‐cultural training before expatriation was not involved in any of the identified relationships. In most conditions, protégé experience and peer support were associated with higher job satisfaction for expatriates of Arab origin. Finally, gender did not play a moderating role in the relationship of work attitudes with mentoring or peer support. These results shed light on the factors that help determine the success of non‐corporate‐sponsored expatriates and have implications for practice and future research. © 2009 Wiley Periodicals, Inc.
The international assignments of peacekeepers: What drives them to seek future expatriation?
Authors: Emmerik IJ. Hetty Van , Euwema Martin C.
Published: January 2009

From a social learning perspective, factors predicting seeking future international assignments and that are more or less under control of the human resource management department through training were examined. We tested our hypotheses on data from 745 Dutch peacekeepers. It appears that preparation, adventurism, and cultural empathy are important factors in willingness to expatriate again. Peacekeepers scoring high on self‐effi cacy are more willing to accept future international assignments than peacekeepers scoring low on self‐effi cacy. Further, the relationship between adventurism and seeking future international assignments is stronger for peacekeepers scoring high on self‐effi cacy than for peacekeepers scoring low on self‐effi cacy. © 2009 Wiley Periodicals, Inc.
Protein profile study of breast‐tissue homogenates by HPLC‐LIF
Authors: Kumar K. Kalyan , Chowdary M. V. P. , Mathew Stanley , Rao Lakshmi , Krishna C. Murali , Kurien Jacob
Published: January 2009

Proteomics is a promising approach for molecular understanding of neoplastic processes including response to treatment. Widely used 2D‐gel electrophoresis/Liquid chromatography coupled with mass spectrometry (LC‐MS) are time consuming and not cost effective. We have developed a high‐sensitivity (femto/subfemtomoles of protein/20 μl) High Performance Liquid Chromatography‐Laser Induced Fluorescence HPLC‐LIF instrument for studying protein profiles of biological samples. In this study, we have explored the feasibility of classifying breast tissues by multivariate analysis of chromatographic data. We have analyzed 13 normal, 17 malignant, 5 benign and 4 post‐treatment breast‐tissue homogenates. Data was analyzed by Principal Component Analysis PCA in both unsupervised and supervised modes on derivative and baseline‐corrected chromatograms. Our findings suggest that PCA of derivative chromatograms gives better classification. Thus, the HPLC‐LIF instrument is not only suitable for generation of chromatographic data using femto/subfemto moles of proteins but the data can also be used for objective diagnosis via multivariate analysis. Prospectively, identified fractions can be collected and analyzed by biochemical and/or MS methods. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient and safe disposal of chrome shavings discharged from leather industry using thermal combustion
Authors: Swarnalatha Somasundaram , Ganesh Kumar Arumugam , Tandaiah Srinivasulu , Sekaran Ganesan
Published: January 2009

BACKGROUND: The high concentration of trivalent chromium along with organic/inorganic compounds in shavings (ChS) discharged from leather industries causes severe groundwater contamination in land disposal and chronic air pollution during thermal incineration. In the present investigation, ChS were subjected to incineration at 800 °C in a thermal incinerator under different volumes of oxygen to optimize the flow rate of oxygen to prevent the conversion of Cr3+ to Cr6+ (starved air combustion) followed by solidification and stabilization of calcined shavings.

RESULTS: Net energy changes resulting from the combustion of shavings showed that the energy of the organic fractions is utilized to the maximum extent at an O2 flow rate of 3.0 g min−1. The ChS were effectively solidified/stabilized using Portland cement and fine aggregate. The unconfined compressive strength of the blocks was in the region of 160 kg cm−2. Leachability studies using a toxicity characterization of leachate procedure test (TCLP) on a solidified block were carried out to determine the percentage metal fixation and dissolved organic (as chemical oxygen demand) concentration in the leachate.

CONCLUSION: The stabilization of chromium(III) in the cement gel matrix was confirmed using different instrumental techniques. The leaching characteristics through TCLP confirmed the effective stabilization of chromium; i.e., the metal fixing capacity was 99.95%. Copyright © 2009 Society of Chemical Industry
Aerobic granules for low‐strength wastewater treatment: formation, structure, and microbial community
Authors: Wang Shu‐Guang , Gai Li‐Hong , Zhao Li‐Jian , Fan Mao‐Hong , Gong Wen‐Xin , Gao Bao‐Yu , Ma Yue
Published: January 2009

BACKGROUND: To validate the possibility of aerobic granulation at a lower organic loading rate (OLR) than 2 kg COD m−3 day−1 (GS 1) in a sequencing batch reactor (SBR), the formation, structure, and microbial community of granular sludge (GS) were investigated.

RESULTS: The overall experimental process involved the following stages: acclimation, granulation, maturation, and stabilization. The optical microscopic showed the structural changes from fluffy activated sludge (AS) to GS and scanning electron microscope (SEM) examination revealed that GS 1 was irregular filamentous aggregates composed mainly of various filamentous species, while the aerobic granules cultivated at OLR 1.68–4.20 kg COD m−3 day−1 (GS 2) was mycelial pellets consisting of fungi and filamentous microorganisms. A Biolog Ecoplate analysis indicated that significant differences existed between the microbial community structure and the substrate's utilization of AS and different GS samples.

CONCLUSION: GS 1 was achieved and different from GS 2 in the formation, structure, and microbial community. Aerobic granulation with low strength wastewater is of importance for the full‐scale application of this technology. Copyright © 2009 Society of Chemical Industry
Epitope mapping of a chimeric CD137 mAb: a necessary step for assessing the biologic relevance of non‐human primate models
Authors: Chan Siaw‐Lin , Voskens Caroline J. , Lin Wei , Schindler Daniel G. , Azimzadeh Agnes , Wang Lai‐Xi , Taylor Rodney J. , Strome Scott E. , Schulze Dan H.
Published: January 2009

Antibody based manipulation of the CD137 (4‐1BB) co‐signaling pathway is an attractive option for the treatment of cancer and autoimmune disease. We developed a chimeric anti‐human CD137 monoclonal antibody (GG) and characterized its function. As a component of planned preclinical studies, we evaluated the binding of GG to activated peripheral blood mononuclear cells (PBMCs) from cynomolgus macaque and baboon against human. Interestingly, GG only recognized human CD137, while a commercial anti‐CD137 mAb (4B4‐1), recognized activated PBMCs from both human and non‐human primates (NHP). Subsequent analysis revealed that the amino acid sequence of CD137 is largely conserved between primate species (∼95% identical), with the extracellular domain differing by only 9–10 amino acids. Based on these data, we generated mutant constructs in the extracellular domain, replacing NHP with human CD137 sequences, and identified 3 amino acids critical for GG binding. These residues are likely part of a conformational epitope, as a peptide spanning this region is unable to block mAb binding. These data demonstrate that subtle sequence variations of defined co‐stimulatory molecules amongst primate species can be employed as a strategy for mapping residues necessary for antibody binding to conformational epitopes. Copyright © 2009 John Wiley & Sons, Ltd.
Screening HIV‐1 antigenic peptides as receptors for antibodies and CD4 in allosteric nanosensors
Authors: Ferraz Rosa María , Rodríguez‐Carmona Escarlata , Ferrer‐Miralles Neus , Meyerhans Andreas , Villaverde Antonio
Published: January 2009

We have analyzed the suitability of six antigenic peptides from several HIV‐1 structural proteins (namely gp41, gp120, p17, and p24), as anti‐HIV‐1 antibody receptors in an allosteric enzymatic biosensor. These peptides were inserted in a solvent‐exposed surface of Escherichia coli (E. coli) beta‐galactosidase by means of conventional recombinant DNA technology. The resulting enzymes were tested to allosterically respond to sera from HIV‐1‐infected individuals. Only stretches from gp41 and gp120 envelope proteins were able to transduce the molecular contact signal in the presence of immunoreactive sera. Intriguingly, the enzyme displaying the CD4 binding site segment KQFINMWQEVGKAMYAPP was activated by soluble CD4, suggesting that it produces conformational modifications on the allosteric enzyme as those occurring during antibody‐promoted induced fit. This fact is discussed in the context of the design of smart protein drugs and markers targeted to CD4+ cells. Copyright © 2009 John Wiley & Sons, Ltd.
Bioclimatic mapping using geostatistical approaches: application to mainland Portugal
Authors: Mesquita S. , Sousa A. J.
Published: January 2009

Spatial interpolation of all the variables necessary for the bioclimatic classification of mainland Portugal, according to the system known as ‘Worldwide Bioclimatic Classification System’ (WBCS), was carried out. Such classification aims to establish a consistent relationship between worldwide vegetation types and easy‐to‐calculate bioclimatic indexes. Despite being relatively small, the Portuguese territory exhibits considerable climatic contrasts, ranging from mediterranean summer‐dry areas in the south, to hyper‐humid temperate mountains in the northwest. The territory has a somewhat sparse network of meteorological stations.

In the scope of the WBCS, Compensated Thermicity Index, Annual Ombrothermic Index, Ombrothermic Index of the Summer Bimonth and of the Summer Trimester, Summer Compensated Ombrothermic Index and Positive Temperature were estimated throughout the study area using several interpolation techniques: multiple linear regression (MLR), ordinary kriging, kriging with external drift using three different drift models, and MLR followed by ordinary kriging of the residuals. The best geostatistical estimator for each variable was chosen taking into account both cross‐validation and visual inspection of the produced maps. The best estimates for the studied indexes were produced using multivariate geostatistical techniques: kriging with external drift (using multiple regression) and multiple regression followed by ordinary kriging of the residuals. Comparison among different geostatistical approaches for all interpolated indexes shows that in low‐sampling density areas, choosing the right set of predictor data is as important as choosing the right interpolation technique. Moreover, natural vegetation types were considered a reliable bioclimatic indicator—as an external criterion—for the evaluation of these maps, and confirmed these results.

Finally, a bioclimatic diagnosis of the entire studied territory was accordingly derived by map algebra, from interpolations, resulting in two bioclimatic maps: those of ombrotypes and thermotypes. Copyright © 2009 Royal Meteorological Society
Nutrient mobilization and nutrient contents of Zea mays in response to EDTA additions to heavy‐metal‐contaminated agricultural soil
Authors: Neugschwandtner Reinhard W. , Tlustoš Pavel , Komárek Michael , Száková Jiřina
Published: January 2009

Enhanced phytoextraction of heavy metals (HMs) using chelating agents and agricultural crops is widely tested as remediation technique for agricultural soils contaminated with less mobile HMs. Nutrients are complexed by chelating agents simultaneously to HMs. In this study, the effect of EDTA (ethylenediaminetetraacetic acid) application on nutrient mobility in the soil and nutrient contents of Zea mays was tested on the laboratory and on the field scale. EDTA effectively increased the mobility of total water‐soluble macronutrients (Ca, K, Mg, P) and micronutrients (Fe, Mn) in the soil solution. Thereby nutrient co‐mobilization did cause competition to target HMs during the phytoextraction process. Mobilization was caused by complexation of nutrient cations by negatively charged EDTA and by dissolution of oxides and hydroxides. Increased concentrations of negatively charged P indicate the dissolution of metal phosphates by EDTA. Higher total water‐soluble nutrient concentrations enhanced bioavailability and plant contents of all determined nutrients especially that of Fe. Mobilization of nutrients may result in leaching and loss of soil fertility.
Metal ion analysis using microchip CE with chemiluminescence detection based on 1,10‐phenanthroline–hydrogen peroxide reaction
Authors: Nogami Takahiro , Hashimoto Masahiko , Tsukagoshi Kazuhiko
Published: January 2009

We developed a microchip CE method with chemiluminescence (CL) detection using the reaction of 1,10‐phenanthroline and hydrogen peroxide for separation and determination of metal ions, where the metal ions acted as catalysts for the CL reaction. The microchip consisted of two microchannels that crossed at the intersection and four reservoirs that accessed the ends of the channels. The metal ions in the sample solution migrated in the channel along with 1,10‐phenanthroline included in a running solution, and then mixed with hydrogen peroxide in one of the reservoirs to emit CL. The light was detected with a photomultiplier tube located just above the reservoir. Two metal ion groups, the platinum metal group (Ru(III), Rh(III), Pd(II), Os(VIII), Ir(III), and Pt(IV)) and the fourth periodic transition metal group (Cu(II), Fe(II), Co(II), and Ni(II)) were examined using the present system. The lowest detection limit was observed for Os(VIII); Os(VIII) responded over the range of 7.5×10–12–1.0×10–8 M with the detection limit of 7.5×10–12 M (about 38 zmol) (S/N = 3). The mixed solution of Ru(III), Rh(III), Pd(II), Os(VIII), Ir(III), and Pt(IV) could be analyzed using this system within about 2.5 min. In addition, the system was applied to the determination of Cu(II) concentration in a city water supply.
Analysis of polycyclic aromatic hydrocarbons in atmospheric particulate samples by microwave‐assisted extraction and liquid chromatography
Authors: Castro Dionísia , Slezakova Klara , Oliva‐Teles Maria Teresa , Delerue‐Matos Cristina , Alvim‐Ferraz Maria Conceição , Morais Simone , Carmo Pereira Maria
Published: January 2009

A methodology based on microwave‐assisted extraction (MAE) and LC with fluorescence detection (FLD) was investigated for the efficient determination of 15 polycyclic aromatic hydrocarbons (PAHs) regarded as priority pollutants by the US Environmental Protection Agency and dibenzo(a,l)pyrene in atmospheric particulate samples. PAHs were successfully extracted from real outdoor particulate matter (PM) samples with recoveries ranging from 81.4 ± 8.8 to 112.0 ± 1.1%, for all the compounds except for naphthalene (62.3 ± 18.0%) and anthracene (67.3 ± 5.7%), under the optimum MAE conditions (30.0 mL of ACN for 20 min at 110°C). No clean‐up steps were necessary prior to LC analysis. LOQs ranging from 0.0054 ng/m3 for benzo(a)anthracene to 0.089 ng/m3 for naphthalene were reached. The validated MAE methodology was applied to the determination of PAHs from a set of real world PM samples collected in Oporto (north of Portugal). The sum of particulate‐bound PAHs in outdoor PM ranged from 2.5 and 28 ng/m3.
Statistical mixture design investigation of fractionated and total extracts fromErythrina speciosaAndrews leaves
Authors: Soares Patricia Kaori , Bruns Roy Edward , Scarminio Ieda Spacino
Published: January 2009

The simplex centroid mixture design for the ethanol, dichloromethane, hexane and acetone solvents has been applied to the extraction of crude mass and the fiber, organic, neutral and basic fractions as well as the fractionation residues ofErythrina speciosaAndrews leaves. Binary and ternary synergic solvent interactions are seen to provide dominant contributions to the extraction of both crude mass and all the fractions. Quadratic and special cubic mixture models precisely predict the extracted quantities of each fraction and the residue as a function of the proportions of the four solvents. Different solvent mixtures are found to be the most efficient extractors for the different fractions: binary dichloromethane‐hexane mixtures for the fiber fraction, ternary ethanol‐dichloromethane‐acetone mixtures for the neutral fraction, binary ethanol‐dichloromethane mixtures for the organic fraction, crude extract and residue values and ternary ethanol‐dichloromethane‐hexane mixtures for the basic fraction. Principal component analysis shows that the ethanol‐dichloromethane mixtures are important for extracting large quantities of the basic and organic fractions as well as of the residue and crude masses.
Application of HPLC‐NMR for the Rapid Chemical Profiling of a Southern Australian Sponge, Dactylospongia sp.
Authors: Dias Daniel Anthony , Urban Sylvia
Published: January 2009

Rapid chemical profiling of the antitumour active crude dichloromethane extract of the marine sponge, Dactylospongia sp. was undertaken. A combination of both offline (HPLC followed by NMR and MS) and on‐line (on‐flow and stop‐flow HPLC‐NMR) chemical profiling approaches was adopted to establish the exact nature of the major constituents present in the dichloromethane extract of this sponge. On‐flow HPLC‐NMR analysis was employed to initially identify components present in the dichloromethane extract, while stop‐flow HPLC‐NMR experiments were then conducted on the major component present, resulting in the partial identification of pentaprenylated p‐quinol (5). Subsequent off‐line RP semi‐preparative HPLC isolation of 5 followed by detailed spectroscopic analysis using NMR and MS permitted the complete structure to be established. This included the first complete carbon NMR chemical shift assignment of 5 based on the heteronuclear 2‐D NMR experiments, together with the first report of its antitumour activity. This study represents one of the few reports describing the application of HPLC‐NMR to chemically profile secondary metabolites from a marine organism.
Assessing visitor preferences in the management of archaeological and heritage attractions: a case study of Hadrian's Roman Wall
Authors: Willis Kenneth G.
Published: January 2009

Managing archaeological and heritage sites requires information on visitor preferences to guide displays of cultural exhibits. A choice experiment is used to investigate visitor preferences in the management of Vondolanda Roman fort, within Hadrian's Wall World Heritage Site. It assesses visitor preferences, utility and value of attributes of the site: excavation and research, interpretation information, museum displays, reconstructions, visitor amenities and admission price. Interaction effects between attributes are analysed. The analysis reveals a preference for the status quo and greater choice uncertainty associated with alternative hypothetical attribute bundles. Neighbouring substitute Roman forts affect the price that visitors are willing to pay for entry. Copyright © 2009 John Wiley & Sons, Ltd.
Impact of preoperative overt hepatic encephalopathy on neurocognitive function after liver transplantation
Authors: Sotil Eva U. , Gottstein Jeanne , Ayala Edgar , Randolph Christopher , Blei Andres T.
Published: January 2009

In the current Model for End-Stage Liver Disease allocation system, patients are at risk of suffering repeated episodes of hepatic encephalopathy (HE) while waiting for an orthotopic liver transplantation (OLT); the posttransplantation impact of these episodes has not been well explored. We evaluated the cognitive function and quality of life in a group of OLT recipients (n = 25) who had suffered from overt HE prior to their procedure (HE-PreLT group) and compared their performance to that of a similar group of patients (n = 14) without overt HE (No HE-PreLT group) as well as to controls. Patients were selected from a cohort of 280 patients who underwent OLT during this period; the presence of clinical confounders excluded many of the remaining subjects. Demographic and clinical characteristics were balanced among groups. At an average of 18 months after OLT, we administered 2 neuropsychological batteries [Psychometric Hepatic Encephalopathy Score (PHES) test battery and Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)]; a pyschophysiological test (critical flicker frequency); and the SF-36 quality of life score. The HE-PreLT group scored below controls in 5 of 6 cognitive domains tested by RBANS, 3 of 6 PHES subtests, as well as the critical flicker frequency test. The No HE-PreLT group scored below the controls in 1 of the 6 cognitive domains tested by RBANS. The more severe neurocognitive abnormalities seen in the HE-PreLT group did not appear to affect quality of life, as lower values than normative data were only found in 1 of the 8 SF-36 scales. In conclusion, neurocognitive abnormalities were more severe in liver transplant recipients that had suffered from overt HE prior to OLT. Prospective studies of neurocognitive function pre-OLT and post-OLT are needed to fully determine the impact of such abnormalities.
Delayed splenic artery occlusion for treatment of established small-for-size syndrome after partial liver transplantation
Authors: Humar Abhinav , Beissel Joy , Crotteau Shaina , Cohen Melissa , Lake John , Payne William D.
Published: January 2009

We looked at the impact of delayed splenic artery occlusion (SAO) on recipients with established small-for-size syndrome (SFSS) after partial graft liver transplantation [either from a living donor (LD) or split from a deceased donor (DD)]. Between 1999 and 2007 we performed a total of 100 partial liver transplantations in adult recipients: 66 LD transplantations and 34 DD split transplantations. Of these, 7 (7%) developed SFSS, diagnosed by the clinical features of cholestasis, coagulopathy, and ascites. Mean graft weight/recipient weight (GW/RW) ratio in these 7 recipients was 0.94%. Five of these 7 recipients underwent relaparotomy at a mean of 10 days post-transplantation to rule out a technical complication, and then intraoperative splenic artery ligation was performed. The other 2 recipients were treated radiologically by splenic artery coiling—at 9 and 13 days post-transplantation. Median serum bilirubin at the time of the splenic artery procedure was 20 mg/dL; by 3 weeks postprocedure this had decreased to 2.5 mg/dL. Of the 7 recipients with SFSS, 6 improved and eventually obtained normal graft function; 1 recipient did not improve and ultimately underwent retransplantation because of persistent cholestasis and failure to thrive. Delayed SAO represents a potential option for the treatment of recipients with established SFSS after partial liver transplantation.
Pharmacokinetics, efficacy, and safety of mycophenolate mofetil in combination with standard-dose or reduced-dose tacrolimus in liver transplant recipients
Authors: Nashan Björn , Saliba Faouzi , Durand Francois , Barcéna Rafael , Herrero Jose Ignacio , Mentha Gilles , Neuhaus Peter , Bowles Matthew , Patch David , Bernardos Angel , Klempnauer Jürgen , Bouw René , Ives Jane , Mamelok Richard , McKay Diane , Truman Matt , Marotta Paul
Published: January 2009

The pharmacokinetics of mycophenolate mofetil (MMF) in liver transplant recipients may change because of pharmacokinetic interactions with coadministered immunosuppressants or because changes in the enterohepatic anatomy may affect biotransformation of MMF to mycophenolic acid (MPA) and enterohepatic recirculation of MPA through the hydrolysis of mycophenolate acid glucuronide to MPA in the gut. In the latter case, the choice of formulation (oral versus intravenous) could have important clinical implications. We randomized liver transplant patients (n = 60) to standard (10–15 ng/mL) or reduced (5–8 ng/mL) trough levels of tacrolimus plus intravenous MMF followed by oral MMF (1 g twice daily) with corticosteroids. Pharmacokinetic sampling was performed after the last intravenous MMF dose, after the first oral MMF dose, and at selected times over 52 weeks. The efficacy and safety of the 2 regimens were also assessed. Twenty-eight and 27 patients in the tacrolimus standard-dose and reduced-dose groups, respectively, were evaluated. No significant differences between the tacrolimus standard-dose and reduced-dose groups were seen in dose-normalized MPA values of the time to the maximum plasma concentration (1.25 versus 1.28 hours), the maximum plasma concentration (15.5 ± 7.93 versus 13.6 ± 7.03 μg/mL), or the area under the concentration-time curve from 0 to 12 hours (AUC0–12; 53.0 ± 20.6 versus 43.8 ± 15.5 μg h/mL) at week 26 or at any other time point. No relationship was observed between the tacrolimus trough or AUC0–12 and MPA AUC0–12. Exposure to MPA after oral and intravenous administration was similar. Safety and efficacy were similar in the two treatment groups. In conclusion, exposure to MPA is not a function of exposure to tacrolimus. The similar safety and efficacy seen with MMF plus standard or reduced doses of tacrolimus suggest that MMF could be combined with reduced doses of tacrolimus.
Overexpression of indoleamine dioxygenase in rat liver allografts using a high-efficiency adeno-associated virus vector does not prevent acute rejection
Authors: Laurence Jerome M. , Wang Chuanmin , Zheng Maolin , Cunningham Sharon , Earl John , Tay Szun Szun , Allen Richard D. M. , McCaughan Geoffrey W. , Alexander Ian E. , Bishop Alex G. , Sharland Alexandra F.
Published: January 2009

The aim of this study was to evaluate the ability of local overexpression of indoleamine dioxygenase (IDO) to abrogate rat liver transplant rejection by the use of an adeno-associated virus vector [recombinant adeno-associated virus 2/8 (rAAV2/8)] to deliver the transgene to the allograft prior to transplantation. A green fluorescent protein (GFP)–expressing vector [recombinant adeno-associated virus 2/8–liver-specific promoter 1–enhanced green fluorescent protein (rAAV2/8-LSP1-eGFP)] was used to examine the kinetics of expression and optimal dosing for transduction of Piebald Virol Glaxo (PVG) rat livers. A vector encoding the rat IDO gene (rAAV2/8-LSP1-rIDO) was constructed and tested by its ability to induce tryptophan catabolism and kynurenine production in vitro and in vivo. PVG donor rats were injected, via the portal vein, with rAAV2/8-LSP1-rIDO 2 weeks before transplantation into PVG strain isograft or Lewis (LEW) strain allograft recipients. With the enhanced GFP vector, 29.5% and 47.4% of hepatocytes were found to express GFP at 3 and 6 weeks after injection, respectively. In untransplanted PVG animals, the rAAV2/8-LSP1-rIDO vector induced, 3 weeks after administration, a 1.8-fold increase (P = 0.0161) in liver IDO activity, which was associated with a fall in serum tryptophan to 0.5 times the baseline level (P < 0.001). PVG recipients of PVG liver isografts pretreated with the IDO-expressing vector had a 45% lower level of serum tryptophan than recipients of isografts pretreated with the GFP-expressing vector (P = 0.03). LEW recipients of PVG liver allografts pretreated with the rat IDO vector had a median survival time of 12 days, whereas recipients of allografts pretreated with rAAV2/8-LSP1-eGFP had a median survival time of 13 days (P = 0.38). Both groups displayed similar histological features of acute cellular rejection. In conclusion, rAAV2/8 vectors produce highly efficient, though delayed, hepatocyte transduction in vivo and provide a useful gene delivery tool for transplantation models. However, gene delivery using IDO was unsuccessful in prolonging rat liver allograft survival.
Pediatric liver retransplantation: Outcomes and a prognostic scoring tool
Authors: Davis Adam , Rosenthal Philip , Glidden David
Published: January 2009

Nine to twenty-nine percent of pediatric liver transplant recipients require retransplantation. No previous pediatric study has proposed a prognostic scoring system. We have used the United Network for Organ Sharing transplantation database to conduct a retrospective cohort study of patients who were less than 18 years of age when they received their retransplant (n = 1130). Using a random two-thirds of the subjects, we developed a prognostic scoring system by performing a multivariate Cox analysis with non-laboratory clinical characteristics. The scoring system was verified in the remaining one-third of the subjects. Stratifying the verification group into risk groups by prognostic score demonstrated its predictive value. Those in the low-risk category had survival similar to that of primary liver transplant recipients. Those in the high-risk category had 2.4 (95% confidence interval: 1.6-3.7) times the risk of death or retransplantation as those in the low-risk category. Risk factors in the scoring system included being on life support at the time of retransplant, receiving a split liver graft, and having an original diagnosis of neonatal cholestasis, familial cholestasis, paucity of bile ducts, or congenital abnormalities. Protective factors in the scoring system included older age at the time of transplantation and having acute rejection contribute to graft failure. In conclusion, with simple clinical characteristics, this scoring tool can modestly discriminate between those children at high risk and those children at low risk of poor outcome after liver retransplantation.
Architectural changes during regenerative and ontogenic liver growth in the rat
Authors: Papp Veronika , Dezsö Katalin , László Viktória , Nagy Peter , Paku Sándor
Published: January 2009

Although liver architecture has a major impact on function, morphological aspects of liver growth are relatively neglected. In our recent experiments, the architectural changes of the rat liver were compared during 2 basic processes: ontogeny and regenerative liver growth. The hepatic tissue is constructed as structural/functional units, and probably the most established and well-defined such unit is the classic lobule. The extent and orientation of the lobules are variable in the liver, and this renders their accurate size determination more difficult. The filling of the liver vasculature by a colored resin nicely outlined the surface lobules, enabling an analysis of the alterations of these structures during liver growth. There are 3 structural components of postnatal physiological liver development: enlargement of the hepatocytes and expansion and multiplication of the liver lobules. However, the enlargement of the lobules is exclusively responsible for the regenerative liver growth following partial hepatectomy. The number of hepatic lobules does not change during this latter reaction, but they gain a more complex, irregular structure.