bluuebunny/crossref_metadata_2025 huggingface dataset:
American Muslim Politics
Authors: Leonard Karen
Published: June 2003

This overview of American Muslim politics surveys the major communities and organizations of Muslims in the USA and their discourses before and after 11 September 2001. African Americans, Arab Americans and South Asian Americans are the three largest groups, and, after setting out their differences, the political discourses and practices drawing them together in American politics are analyzed. The important conflict between the many new, western-educated professional leaders of the Muslim political coalitions in the US, whose knowledge of classical Islamic civilization and law is not great, and the fewer numbers of classically-trained legal scholars is discussed, leading to a review of personal issues that are also intensely political, particularly those concerning gender roles. 11 September produced challenges to the new professional leadership from the mainstream American media and government officials, opening up the field of discourse about Muslims in America. This has led to a greater focus on US domestic issues and perhaps a larger role for the young generation of American Muslims. The overall trajectory is that of an evolving and distinctively American set of Muslim discourses and practices.
Expiratory chest radiographs do not improve visibility of small apical pneumothoraces by enhanced contrast
Authors: Schramel FM , Golding RP , Haakman CD , Sutedja TG , de Jong KA , Postmus PE
Published: June 2003

Demonstration of small apical pneumothoraces is supposed to be facilitated by expiratory chest radiographs. This study aimed to analyse the assumed enhancement of visual contrast on expiratory chest radiographs in patients with small apical pneumothoraces. Optical densities (OD) were obtained with a densitometer (X-rite 3001) on 54 paired inspiratory and expiratory chest radiographs of 22 consecutive patients with small apical pneumothoraces. The ODs were measured: at the intervertebral space between the first and second thoracic vertebrae (Area 1); at the peripheral part of the affected lung parenchyma (Area 2); and at the adjacent intrapleural space (Area 3). Excellent correlations of OD of each area were obtained between paired inspiratory and expiratory chest radiographs. The ODs of all areas on expiratory chest radiographs were significantly higher than on inspiratory chest radiographs. Contrast between pulmonary parenchyma and intrapleural air in inspiratory and expiratory films did not differ significantly. Expiratory chest radiographs do not improve visibility of small apical pneumothoraces by enhanced contrast between pulmonary parenchyma and intrapleural air. Expiratory chest radiographs show equally increased OD in the area of lung tissue and intrapleural air, caused by increased extrapulmonary tissue density during expiration, resulting in increased radiation exposure monitored by the ionization chambers of standard radiological equipment. If expiratory chest radiographs are really improving the visibility of apical pneumothoraces, there must be other reasons than contrast enhancement to explain this.
Modulation of ICAM-1 expression in human alveolar macrophages in vitro
Authors: Fattal-German M , Ladurie FL , Cerrina J , Lecerf F , Berrih-Aknin S
Published: June 2003

Modulation of intercellular adhesion molecule-1 (ICAM-1) expression may be a basic mechanism by which alveolar macrophages (AMs) regulate the inflammatory process in the lung in response to local stimuli. As a model for studying the anti-inflammatory activity of drugs on human AMs, we investigated the effects of fusafungine, an antibiotic for local use by aerosol with anti-inflammatory properties, and that of the glucocorticoid dexamethasone, on ICAM-1 expression induced in vitro by recombinant interferon-gamma (rIFN-gamma). ICAM-1 protein expression was studied on AMs by means of flow cytometry with an anti-CD54 monoclonal antibody; messenger ribonucleic acid (mRNA) levels were determined by reverse transcriptase-polymerase chain reaction (RT-PCR). ICAM-1 was expressed before culture on 21% of bronchoalveolar lavage (BAL) cells, with low intensity. Culture for 24 h with rIFN-gamma resulted in a significant increase in ICAM-1 protein expression (82% of cells were strongly positive). Fusafungine significantly inhibited rIFN-gamma-induced ICAM-1-protein expression on AMs in a concentration-dependent fashion. The mechanism of ICAM-1 downregulation was mainly post-transcriptional, but also partly transcriptional. By contrast, dexamethasone did not influence rIFN-gamma-induced ICAM-1 expression. This in vitro model using human AMs should prove useful for investigating the cellular and molecular targets of anti-inflammatory drugs.
Evaluation of methacholine dose-response curves by linear and exponential mathematical models: goodness-of-fit and validity of extrapolation
Authors: Verlato G , Cerveri I , Villani A , Pasquetto M , Ferrari M , Fanfulla F , Zanolin E , Rijcken B , de Marco R
Published: June 2003

Several models have been proposed to analyse dose-response curves recorded in bronchoprovocation challenge tests. The aims of the present work were: 1) to investigate which model (linear vs exponential) and which minimization method (trials and errors vs Levenberg-Marquardt) gives better results in terms of data interpolation (goodness-of-fit); and 2) to verify the validity of extrapolation by comparing forced expiratory volume in one second (FEV1) observed after 4 mg methacholine with values extrapolated after truncation of the curves at 2 mg. For these purposes, methacholine dose-response curves were obtained in 832 subjects from a random population sample, as part of the European Community Respiratory Health Survey (ECRHS) in Italy. Methacholine was inhaled up to a maximum dose of 6 mg by dosimeter technique. The coefficient of determination (r2) was significantly higher with the exponential model (0.81 +/- 0.22; mean +/- SD) than with the linear model (0.69 +/- 0.27). With both models, extrapolated values were usually lower than observed values. As a consequence, a 20% fall in FEV1 with respect to postsaline FEV1 was observed in only 24% and 21% of the tests, where a 20% fall had been predicted, respectively, according to the linear and exponential model. In conclusion, exponential models are better than linear models with respect to data interpolation of methacholine dose-response curves. However, they are worse with respect to extrapolation to higher doses. With any model, extrapolation of dose-response curves by one doubling-dose should be avoided.
Relationship between supramaximal flows and flow-limiting mechanisms
Authors: Sala H , Galindez F , Badolati A , Rodenstein D
Published: June 2003

The aim of this study was to evaluate the relationship between supramaximal flows (SF) and indices of airway mechanics. We studied 26 asymptomatic young subjects (13 smokers, mean +/- SD 15.9 +/- 6.6 pack-years. Subjects performed maximal expiratory flow-volume (MEFV) curves, according to the American Thoracic Society (ATS) criteria, on a rolling-seal spirometer and then repeated them through a specially devised valve, which occluded the mouthpiece either 3 or 6 times.s-1 with a ratio of open:closed time of 3:1. Envelope MEFV curves for 3 and 6 Hz occlusions were constructed passing through the SF obtained after each occlusion, and the increment in flow at 50% of vital capacity was measured with respect to the basal curve (delta V' max50). We found that the delta V' max50 at 3 and 6 Hz correlated to the baseline forced mid-expiratory flow (FEF25-75) in % of predicted value (r = -0.73 and r = -0.55, respectively). our results suggest that inhomogeneities within the lung are an important mechanism in the occurrence of supramaximal flow in normal subjects.
Surfactant protein-A levels increase during Pneumocystis carinii pneumonia in the rat
Authors: Phelps DS , Umstead TM , Rose RM , Fishman JA
Published: June 2003

In bronchoalveolar lavage (BAL) of human immunodeficiency virus (HIV)-infected patients with Pneumocystis carinii pneumonia and in lungs of glucocorticoid-immunosuppressed rats infected with P. carinii, surfactant phospholipid levels are reduced. However, levels of the surfactant-associated protein-A (SP-A) in BAL are 4-5 times higher than normal in patients with P. carinii pneumonia. In this study, we examined the effects of glucocorticoid immunosuppression and P. carinii infection on SP-A messenger ribonucleic acid (mRNA) and protein levels in rat lungs. Rats were immunosuppressed by adding dexamethasone to their drinking water and were infected with P. carinii by intratracheal instillation of the organism. SP-A was measured by enzyme-linked immunosorbent assay (ELISA) and SP-A mRNA by hybridization of Northern blots with an SP-A complementary deoxyribonucleic acid (cDNA) probe. There was a severalfold increase in SP-A protein and mRNA levels in uninfected glucocorticoid-treated rats. However, contrary to what has been reported with the surfactant-associated lipids, SP-A mRNA and protein levels in P. carinii-infected animals were significantly higher than those found in the uninfected, immunosuppressed animals. Our results demonstrate that SP-A increases, probably as a result of elevated mRNA levels, in immunosuppressed rats with P. carinii infection and are consistent with our findings in HIV-positive patients with P. carinii pneumonia.
Colony-stimulating factors as an adjunct to chemotherapy in small cell lung cancer
Authors: Urban T , Schuller MP , Lebeau B
Published: June 2003

Myelosuppression is the major dose-limiting toxicity of chemotherapy in small cell lung cancer (SCLC). The capacity of colony stimulating factors (CSFs) to stimulate granular neutrophil recovery may be of great value to prevent or cure febrile neutropenia and to increase dose-intensity. The aim of this review was to assess the current use of CSFs in SCLC on the basis of experimental and clinical data. Primary CSF administration has been shown to reduce the incidence of febrile neutropenia, hospital admission rate, and antibiotic use subsequent to cyclophosphamidedoxorubicin-high dose etoposide (CDE) chemotherapy, without improvement of survival or disease control. Primary CSF administration may be recommended when the expected incidence of febrile neutropenia is at least 40%. This benefit has not been established with less myelosuppressive regimens, such as cisplatin-etoposide (PE), which remains an alternative combination of SCLC when standard doses are used. A trial comparing high-dose CDE + CSF with PE would be of considerable interest. There is currently little clinical basis for the use of CSFs to increase chemotherapy dose-intensity, outside clinical trials. Peripheral blood progenitor cells mobilized with CSFs offer interesting prospects. Further studies, with later initiation, shorter duration or lower doses of CSFs, are warranted to improve the cost-effectiveness of CSFs. CSF therapy in addition to antibiotics is normally not justified in febrile neutropenia, except perhaps in selected patients with sepsis syndromes, hypotension or pneumonia.
Preparation of bronchoalveolar lavage fluid with microscope slide smears
Authors: Thompson AB , Teschler H , Wang YM , Konietzko N , Costabel U
Published: June 2003

The method of preparation of bronchoalveolar lavage fluid (BALF) for cytological examination can significantly affect the results of cellular quantitation. Investigations have shown that cytocentrifugation leads to an underestimation of the number of lymphocytes and membrane filter preparation to an underestimation of the number of neutrophils. As a simple alternative to these two techniques, BALF cells could be prepared by the microscope slide smear technique, which is familiar as the means for preparing peripheral blood for differential counts. In order to compare cell differentials determined by microscope slide technique with differentials resulting from cytocentrifugation, cells were isolated from 35 BALF samples using standard methods, and counted using a haematocytometer. Forty thousand cells in 200 microL were prepared by cytocentrifugation (3 min, 57 x g; Cytospin 2) and 5 x 10(5) cells in 5 microL by microscope slide smear. Both samples were air-dried, stained using May-Grunwald Giemsa stain, and 600 cells were counted to obtain differentials. To test the adequacy of sampling by the microscope slide smear technique, known quantities of lymphocytes or neutrophils were added to fixed numbers of BALF cells, microscope slide smears prepared, and differentials determined on 600 cells. The resulting differentials were compared to the calculated differentials. Preparation of BALF cells with the microscope slide smear technique yielded well-preserved cell morphology. Compared to cytocentrifugation, microscope slide smear preparations had significantly higher percentages of lymphocytes. The microscope slide smears for the samples with predetermined numbers of cells yielded lymphocyte and neutrophil percentages which did not differ from the calculated differentials (59.6 +/- 1.5 vs 59.6 +/- 5.2% and 54.6 +/- 6.0 vs 53.1 +/- 6.0%, respectively). Varying the number of cells counted from 100 to 800 confirmed the reproducibility of the counts for counting 600 cells. Using 5 x 10(5), 2.5 x 10(5), or 1 x 10(5) cells per preparation demonstrated that adequate specimens could be obtained from as few as 1 x 10(5) cells. Thus, microscope slide smear preparation is a simple and accurate method for the quantitation of bronchoalveolar lavage fluid cytology.
Fluoxetin-induced pulmonary granulomatosis
Authors: de Kerviler E , Tredaniel J , Revlon G , Groussard O , Zalcman G , Ortoli JM , Espie M , Hirsch A , Frija J
Published: June 2003

A patient treated with fluoxetin for a manic depressive disorder developed pulmonary inflammatory nodules with noncaseating giant cell granulomas, interstitial pneumonia and non-necrotizing vasculitis, whilst remaining asymptomatic. A progressive resolution of pulmonary nodules occurred after withdrawal of the offending agent, and the chest radiograph returned to normal in 9 months. The diagnosis was assessed by an open lung biopsy.
Criminal outcomes and costs of treatment services for injecting and non-injecting heroin users: evidence from a national prospective cohort survey
Authors: Healey Andrew , Knapp Martin , Marsden John , Gossop Michael , Stewart Duncan
Published: June 2003

Objectives: To assess the incremental cost-effectiveness of drug addiction treatment programmes provided in the UK by the National Health Service and not-for-profit agencies in terms of crime-related outcomes. All costs and crime-related outcomes were implicitly evaluated relative to a 'no treatment' alternative.

Methods: Longitudinal observational data on a national sample of heroin addicts referred to addiction treatment services throughout England were re-analysed. Predictions from a Poisson random-effects model were used to estimate the incremental effectiveness and cost-effectiveness of treatment programmes. Interaction variables were used to assess whether the injecting of heroin on entry to treatment had an impact on cost-effectiveness.

Results: The findings rejected the null hypothesis that increasing time in treatment (and therefore treatment cost) has no mean crime prevention effect on clients referred for community-based methadone treatment, treatment delivered within specialist drug dependency units and residential rehabilitation programmes ( P < 0.05). However, the size of the cost per unit of effect based on model predictions was sensitive to the exclusion of a small group of outlying observations. The interaction between client injecting status and time in treatment was found to be statistically significant ( P < 0.05), with an estimated reduction in treatment cost-effectiveness across all treatment programmes for clients who reported injecting drugs at treatment intake.

Conclusions: Whilst the analyses did not include an evaluation of the effect of treatment programmes on client health and quality of life and stopped short of providing a social weighting for the predicted reduction in crimes, they do offer a useful starting point for establishing the cost-effectiveness of treating heroin addiction. The onus is on public decision-makers to decide whether the predicted reductions in crime are worth the opportunity costs of investing extra resources in a major expansion of treatment services.
General practitioners' uptake of clinical practice guidelines: a qualitative study
Authors: Harrison Stephen , Dowswell George , Wright John , Russell Ian
Published: June 2003

Objective: To explain recent rapid audited change in the uptake of locally implemented, evidence-based clinical guidelines for asthma and angina in primary care.

Methods: A case study of primary care in two matched, adjacent districts in Northern England, focusing on a stratified random sample of 49 general practitioners (GPs) from eight primary care groups. Data were collected from three cycles of mainly qualitative interviews carried out at six-monthly intervals, before and after the dissemination of local guidelines and after audit data were gathered. Interviews examined attitudes, awareness and impact of locally disseminated asthma and angina guidelines and the subsequent audit. Audit data on guideline uptake were also available from a parallel study.

Results: The rapid increase in guideline uptake observed in both intervention and control groups was not explained by individual practitioners or practice factors. The findings are attributed to GPs' awareness of policies for evidence-based medicine, of new health service institutions and of the clinical governance activities of primary care groups. Behaviour change reflects GPs' decisions about what to record in case notes as well as their clinical decisions, so that findings may reflect changing perceptions about accountability rather than about preferred treatment regimes.

Conclusions: Guideline production and dissemination is best seen in the broader context of policy change. Studies of guideline implementation should report before and after data and incorporate significant qualitative components in order to identify important contextual factors.
Flashbulb and factual memories: the case of Rabin's assassination
Authors: Nachson Israel , Zelig Anat
Published: June 2003

Similarities and differences between factual memories (FTM) and flashbulb memories (FBM) of the assassination of Israel's Prime Minister, Itzhak Rabin, were explored. About two weeks after the assassination 61 Israeli students filled out a questionnaire which focused on the event and the circumstances in which they had first learned about it. About 11 months later they filled out again the same questionnaire, and self‐assessed their emotional and cognitive reactions to the assassination, as well as specific properties of their memory; such as confidence in its accuracy, and the amounts of rehearsals and visual representations. Comparative analysis of the participants' responses on the two questionnaires uncovered decrements of about 25% in FTM accuracy, and about 36% in FBM consistency. Rehearsals and visual representations were more common in FTM than in FBM, but the levels of confidence in memory accuracy were similar for both. FTM which were presumably based on information provided by television broadcasts, appeared to have episodic properties. The data seem to support the hypothesis that FTM and FBM of traumatic public events are encoded together; perhaps by the same memory mechanism. Copyright © 2003 John Wiley & Sons, Ltd.
Elektrosprayionisierungs‐Tandem‐Massenspektrometrie im Hochdurchsatz‐Screening homogener Katalysatoren
Authors: Chen Peter
Published: June 2003

Der Vortitel enthält eine Illustration von John Tenniel und einen Auszug aus “Alice im Wunderland” von Lewis Carroll in der Ausgabe von 1865. Weil alles im Wunderland der Logik widerspricht, erklärt die Königin im Prozess gegen Alice: “Zuerst die Strafe, dann das Urteil!” Das üblicherweise praktizierte Hochdurchsatz‐Screening von Katalysatoren beruht auf dem Prinzip “zuerst die Synthese, dann das Screening”, worin, wie in diesem Aufsatz diskutiert wird, ebenfalls die Logik umgekehrt ist. Unter den besonderen Zwangsbedingungen für metallorganische Komplexe ist es effizienter, eine selektive Synthese erst dann zu entwickeln, wenn eine bestimmte Struktur der katalytisch aktivste Kandidat unter vielen zu sein scheint. Demzufolge müssen Screening‐Methoden auch für schlecht definierte Mischungen geeignet sein. Die Elektrosprayionisierungs‐Tandem‐Massenspektrometrie bietet eine ausgezeichnete technische Lösung für dieses Problem.
Tyrosine and peptide reorientational mobility in polymer solutions: Time‐dependent fluorescence anisotropy measurements
Authors: Bothwell Troy G. , Unruh Jay R. , Johnson Carey K.
Published: June 2003

The ability of peptides to form biologically active conformations that bind to receptors is governed by their dynamics and their propensity to form stable structures. Such factors are consequently important in the design of peptide drugs. Moreover, the stability of such peptides depends on interactions of the peptide with the surrounding matrix. In this article, we study the effect of the polymer poly(vinyl pyrrolidone) (PVP) on the mobility and orientational dynamics of tyrosine and a model peptide, Val–Tyr–Pro–Asn–Gly–Ala (VYPNGA) in glycerol–water solutions. Orientational dynamics are studied experimentally by time‐resolved fluorescence anisotropy decays of tyrosine. The presence of PVP leads to the possibility of a distribution of environments for the peptide. The orientational dynamics of tyrosine show that the probe molecule experiences two very different environments. In one, tyrosine rotational motion is weakly coupled to PVP, while in the other, tyrosine interacts strongly with PVP leading to much slower rotational times. The dynamics of VYPNGA are more complex. Fast intramolecular, localized reorientations of the tyrosine are detected. The temperature dependence of the reorientational dynamics of the tyrosine side chain reveal that these motions are shielded from solvent friction. In contrast, global motions of the peptide are severely restricted by PVP, suggesting the ability of the polymer to restrict peptide mobility. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 351–362, 2003
Size and shape of the repetitive domain of high molecular weight wheat gluten proteins. II. Hydrodynamic studies
Authors: van Swieten Eric , Friesen Robert R. , de Kruif Cees G. , Robillard George T.
Published: June 2003

This study describes the hydrodynamic properties of the repetitive domain of high molecular weight (HMW) wheat proteins, which complement the small‐angle scattering (SANS) experiments performed in the first paper of this series. The sedimentation coefficients, s0, and diffusion coefficients, D0, were obtained from the homologuous HMW proteins dB1 and dB4 that were cloned from the gluten protein HMW Dx5, and expressed in Escherichia coli. Monodisperse conditions for accurate determination of s0 and D0, were obtained by screening a series of buffers using dynamic light scattering. For the first time, hydrodynamic parameters were obtained on monodisperse samples that enabled the determination of the monomeric size and shape. The hydrodynamic values determined on dB1 and dB4 were used to test the worm‐like chain (WLC) model that was proposed in the SANS studies. The successful matching of two separately obtained hydrodynamic parameters of dB1 and dB4 using the WLC model provides further evidence for the WLC model. The small discrepancy between the hydrodynamic and scattering data, possibly coming from the excluded volume effect, was compensated by a solvation layer of 1–2 water molecules thick around the protein in the WLC model. The solvation of the central domain is much higher than those of the terminal domains of the HMW subunits. This difference emphasizes the dual role of HMW wheat gluten proteins in water‐binding and aggregation. © 2003 Wiley Periodicals, Inc. Biopolymers 69: 325–332, 2003
Contribution of Raman spectroscopy to identification of biominerals present in teeth of Acanthopleura rehderi, Acanthopleura curtisiana, and Onithochiton quercinus
Authors: Lee Alasdair P. , Brooker Lesley R. , Van Bronswijk Wilhelm , Macey David J. , Webb John
Published: June 2003

Raman spectroscopic investigations of the major lateral teeth of the chitons Acanthopleura rehderi and Acanthopleura curtisiana indicate that, in addition to the magnetite of the cutting surface and a carbonated hydroxyapatite in the central tooth core, these species deposit limonite in place of the lepidocrocite reported for other members of the genus Acanthopleura. A comparison of the spectra from these species with those of Onithochiton quercinus, which also deposits limonite, indicates that the current assignment of these species to Acanthopleura may not be appropriate. Biomineralization of the major lateral teeth may be a useful parameter to include in the taxonomic classification of chiton species. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Recognition of thymine by triazine fluorescent probe through intermolecular multiple hydrogen bonding
Authors: Nie Lihua , Ma Huimin , Li Xiaohua , Sun Ming , Xiong Shaoxiang
Published: June 2003

In order to design a fluorescent probe with a long wavelength and multiple hydrogen bond sites for thymine, 3‐(4‐chloro‐6‐methylamino‐1,3,5‐triazinylamino)‐7‐dimethylamino‐2‐methylphenazine is synthesized by subsequently reacting neutral red and methylamine with cyanuric chloride. Its recognition behavior for thymine and its spectroscopic properties in different solvents are studied. The probe's fluorescence can be selectively quenched by thymine instead of guanine, indicating that fully complementary hydrogen bonding plays a key role in such recognition processes. In addition, the recognition mechanism of the probe for thymine and the bathochromic shift of its fluorescence spectra with the solvent polarity are also discussed. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Resonance Raman spectroscopy study of change of iron spin state in horseradish peroxidase C induced by removal of calcium
Authors: Huang Qing , Laberge Monique , Szigeti Krisztian , Fidy Judit , Schweitzer‐Stenner Reinhard
Published: June 2003

Resonance Raman spectroscopy is used to probe the effect of calcium depletion on the heme group of horseradish peroxidase C at pH 8. Polarized Raman spectra are recorded with an argon ion laser at eight different wavelengths to provide a sound database for a reliable spectral decomposition. Upon calcium depletion, the spectrum is indicative of a predominantly pentacoordinated high spin state of the heme iron coexisting with small fractions of hexacoordinated high and low spin states. The dominant quantum mixed spin state of native ferric horseradish peroxidase, which is characteristic for class III peroxidases, is not detectable in the spectrum of the enzyme with partial distal Ca2+ depletion. The quenching of the quantum mixed spin state and the predominance of the pentacoordinated high spin state are likely to arise from distortions induced by distal calcium depletion, which translates into a weaker Fe‐Nϵ(His) bond and a more tilted imidazole. A correlation is proposed between the lower enzyme activity and the elimination of the pentacoordinated quantum mixed state upon Ca2+ depletion. © 2003 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy), 2003
Simultaneous determination of leflunomide and its active metabolite, A77 1726, in human plasma by high‐performance liquid chromatography
Authors: Schmidt Andreas , Schwind Bianca , Gillich Martin , Brune Kay , Hinz Burkhard
Published: June 2003

The isoxazol derivative leflunomide [N‐(4′‐trifluoromethylphenyl)‐5‐methylisoxazole‐4‐carboxamide] is an inhibitor of de novo pyrimidine synthesis used for the treatment of rheumatoid artrithis. In the present study, a liquid–liquid extraction‐based reversed‐phase HPLC method with UV detection was validated and applied for the analysis of leflunomide and its active metabolite, A77 1726, in human plasma. The analytes were separated using a mobile phase, consisting of acetonitrile, water and formic acid (40/59.8/0.2, v/v), at a flow rate of 0.5 mL/min, and UV detection at 261 nm. The retention times for A77 1726, leflunomide and warfarin (internal standard) were 8.2, 16.2 and 12.2 min, respectively. The validated quantification range of the method was 0.05–100 µg/mL for leflunomide and 0.1–100 µg/mL for A77 1726. The developed procedure was applied to assess steady‐state plasma concentrations of A77 1726 in patients with rheumatoid arthritis treated with 10 or 20 mg leflunomide per day. Copyright © 2003 John Wiley & Sons, Ltd.
A Catalytic Antibody Programmed for Torsional Activation of Amide Bond Hydrolysis
Authors: Aggarwal Ranjana , Benedetti Fabio , Berti Federico , Buchini Sabrina , Colombatti Alfonso , Dinon Francesca , Galasso Vinicio , Norbedo Stefano
Published: June 2003

Amidase antibody 312d6, obtained against the sulfonamide hapten 4 a that mimics the transition state for hydrolysis of a distorted amide, accelerates the hydrolysis of the corresponding amides 1 a–3 a by a factor of 103 at pH 8. The mechanisms of both the uncatalyzed and antibody‐catalyzed reactions were studied. Between pH 8 and 12 the uncatalyzed hydrolysis of N‐toluoylindoles 1 a and 3 a shows a simple first‐order dependence on [OH−], while hydrolysis of 3 a is zeroth‐order in [OH−] below pH 8. The pH profile for hydrolysis of the corresponding tryptophan amide 2 a is more complex due to the dissociation of the zwitterion into an anion with pKa 9.74; hydrolysis of the zwitterionic and the anionic form of 2 a both show simple first‐order dependence on [OH−]. Absence of 18O exchange between H218O/18OH− and the substrate, a normal SKIE for both 1 a (kH/kD=1.12) and 3 a (kH/kD=1.24) and the value of the Hammett constant ρ for hydrolysis of p‐substituted amides 3 a–e are consistent with an ester‐like mechanism in which formation of the tetrahedral intermediate is rate‐determining and the amine departs as anion. The 312d6‐catalyzed hydrolysis of 3 a was studied between pH 7.5 and 9, and its independence of pH in this range indicates that water is the reacting nucleophile. Hydrolysis of 3 a is only partially inhibited by the sulfonamide hapten, and this indicates that non‐specific catalysis by the protein accompanies the specific process. Only the nonspecific process is observed in the hydrolysis of amides 3 with para substituents other than methyl. Binding studies on the corresponding series of p‐substituted sulfonamides 5 a–e confirm the high specificity of antibody 312d6 for p‐methyl substituted substrates.
Interaction of the Benzenium Ion with Inert Ligands: IR Spectra of C6H7+Ln Cluster Cations (L=Ar, N2, CH4, H2O)
Authors: Solcà Nicola , Dopfer Otto
Published: June 2003

IR photodissociation spectra of mass‐selected clusters composed of protonated benzene (C6H7+) and several ligands L are analyzed in the range of the CH stretch fundamentals. The investigated systems include C6H7+Ar, C6H7+(N2)n (n=1–4), C6H7+(CH4)n (n=1–4), and C6H7+H2O. The complexes are produced in a supersonic plasma expansion using chemical ionization. The IR spectra display absorptions near 2800 and 3100 cm−1, which are attributed to the aliphatic and aromatic CH stretch vibrations, respectively, of the benzenium ion, that is, the σ complex of C6H7+. The C6H7+(CH4)n clusters show additional CH stretch bands of the CH4 ligands. Both the frequencies and the relative intensities of the C6H7+ absorptions are nearly independent of the choice and number of ligands, suggesting that the benzenium ion in the detected C6H7+Ln clusters is only weakly perturbed by the microsolvation process. Analysis of photofragmentation branching ratios yield estimated ligand binding energies of the order of 800 and 950 cm−1 (≈9.5 and 11.5 kJ mol−1) for N2 and CH4, respectively. The interpretation of the experimental data is supported by ab initio calculations for C6H7+Ar and C6H7+N2 at the MP 2/6‐311 G(2df,2pd) level. Both the calculations and the spectra are consistent with weak intermolecular π bonds of Ar and N2 to the C6H7+ ring. The astrophysical implications of the deduced IR spectrum of C6H7+ are briefly discussed.
Chiral [RuCl2(dipyridylphosphane)(1,2‐diamine)] Catalysts: Applications in Asymmetric Hydrogenation of a Wide Range of Simple Ketones
Authors: Wu Jing , Ji Jian‐Xin , Guo Rongwei , Yeung Chi‐Hung , Chan Albert S. C.
Published: June 2003

The dipyridylphosphane/diamine–Ru complex combined with tBuOK in 2propanol acts as a very effective catalyst system for the enantioselective hydrogenation of a diverse range of simple ketones including heteroaromatic ketones, substituted benzophenones, alkenyl ketones, and cyclopropyl ketones. The combination of desirable features, such as quantitative chemical yields within hours, broad substrate scope, excellent enantioselectivities (up to 99 %), and high substrate‐to‐catalyst ratios, among others, makes the present catalyst system of high practical interest.
Density Functional Characterization of the Chemoselective Oxidation of Catechol by using Molecular Oxygen: Thermodynamics of the Reaction between [(triphos)Ir(dtbc)]+ and O2
Authors: Bencini Alessandro , Bill Eckhard , Scozzafava Andrea , Totti Federico
Published: June 2003

The catalytic mechanism of intra and extra catechol cleaving dioxygenases is still a matter of debate, because the intermediate transient oxygen adduct has never been isolated in these enzymes. The complex [(triphos)Ir(dtbc)]+ (triphos=MeC(CH2PPh2)3, DBTC2−=3,5‐di‐tert‐butylcatecholate), reacts with molecular oxygen and exhibits a ring‐cleaving catalytic activity, and a stable oxygen intermediate appears; this stimulates an opportunity for obtaining information that can be transferable to the above‐mentioned enzymatic catalytic centers, therefore, giving a breakthrough into the strategy of oxygen activation in these natural systems. Here, we present the results of our computational approach, based on density functional theory, focusing on the following aspects: to explain the interaction with molecular oxygen and how to avoid the existing spin problem, to understand the formation of the bridging moiety, to clarify, if any, the possible influence on the structure of the formed adduct of the bidentate versus monodentate binding of the catechol ligand, and to disclose, eventually, the nature of final decomposition products with the aim to rationalize the intra versus extra cleavage of the catechol molecule itself.
Greener Solvents: Room Temperature Ionic Liquids from Biorenewable Sources
Authors: Handy Scott T.
Published: June 2003

Room temperature ionic liquids (RTILs) have attracted a great deal of interest as environmentally benign (green) solvents for organic synthesis. More recently, RTILs that are chiral, less expensive, or functionalized (protic or Lewis basic) have been developed. In many cases, these new solvents are based on the modification of natural products. This paper is an overview of these new biorenewable RTILs.
Cyclodextrin Phosphanes as First and Second Coordination Sphere Cavitands
Authors: Engeldinger Eric , Armspach Dominique , Matt Dominique , Jones Peter G.
Published: June 2003

The binding properties of two α‐cyclodextrins, each containing two C(5)‐linked “CH2PPh2” units, L 1 (A,D‐substituted) and L 2 (A,C‐substituted), have been investigated. Both ligands readily form transition‐metal chelate complexes in which the metal centres are immobilised at the cavity entrance. Although diphosphane L 1 displays a marked tendency to behave only as a trans‐spanning ligand, the ligand possesses a certain degree of flexibility, for example, allowing the stabilisation of a trigonal silver(I) complex in which the bite angle drops to 143°. Another feature of L 1 concerns its ability to function as an hemilabile ligand. Together with four methoxy groups anchored onto the primary face, the two PIII centres of L 1 form a circularly arranged P2O4 12‐electron donor set able to complex an Ag+ ion in a dynamic way, each of the four oxygen atoms coordinating successively to the silver ion. Furthermore, the particular structures of L 1 and L 2, characterised by the presence of PIII units lying close to the cavity entrance, lead upon complexation to complexes whereby the first coordination sphere is partly entrapped in the cyclodextrin. Thus, when treated with metal chlorides, both ligands systematically produce complexes in which the MCl unit is maintained inside the cyclodextrin through weak Cl⋅⋅⋅H‐5 interactions. The chelate complex [Ag(L 1)]BF4 reacts with acetonitrile in excess to afford a mixture of two equilibrating complexes, [Ag(acetonitrile)(L 1)]BF4 and [Ag(acetonitrile)2(L 1)]BF4, whose coordinated nitriles lie inside the cyclodextrin cavity. The inner‐cavity ligands can be substituted by a benzonitrile molecule. The present study provides the first identification of an [Ag(acetonitrile)2(phosphane)2]+ ion. The unexpected stabilisation of this species probably rests on a cavity effect, the cyclodextrin walls favouring recombination of the complex after facile dissociation of the nitrile ligands.
A Systematic Exploration of Nickel–Pyrazolinato Chemistry with Alkali Metals: New Cages From Serendipitous Assembly
Authors: Aromí Guillem , Bell Aidan R. , Helliwell Madeleine , Raftery James , Teat Simon J. , Timco Grigore A. , Roubeau Olivier , Winpenny Richard E. P.
Published: June 2003

The preparation and properties of fourteen novel paramagnetic [NiIIx] aggregates bridged by pivalate, pyrazolinolate and in most cases hydroxide are reported. A rich structural diversity has been achieved by changing the nature of the alkali of the base used during the synthesis, leading to the nuclearities [NiII4NaI4] (2, 3, 4), [NiII5NaI4] (5, 6, 7), [NiII5LiI6] (8), [NiII8MI2] (M=K (9, 10), Rb (11, 12), Cs (13, 14) and [NiII8] (15). All compounds have been characterised by single‐crystal Xray diffraction; however, full crystallographic details are given only for the representative molecules [Ni4Na4(fpo)4(piv)8(Hpiv)8] (2), [Ni5Na4(OH)2(mpo)4(piv)8(Hpiv)2(MeCN)2] (5), [Ni5Li6(OH)2(fpo)2(piv)12(Hpiv)4] (8), [Ni8K2(OH)4(ppo)4(piv)10(Hppo)2(Hpiv)2(MeCN)2] (9), [Ni8Rb2(OH)4(ppo)4(piv)10(Hppo)2(Hpiv)2(MeCN)2] (11), [Ni8Cs2(OH)4(ppo)4(piv)10(Hppo)2(Hpiv)2(MeCN)2] (13) and [Ni8(OH)4(mpo)2(PhCH2CO2)10(Hmpo)8] (15). Variable‐temperature bulk magnetisation measurements have been performed for each type of complex. The [NiII4NaI4] clusters show intramolecular antiferromagnetic coupling and a spin ground state of S=0. Complexes of the type [NiII5NaI4] also display antiferromagnetic superexchange, leading to an S=1 spin ground state. The molecule with nuclearity [NiII5LiI6], in contrast, exhibits ferromagnetic interactions, resulting in the presence of low energy states with high multiplicity, and a spin ground state S>1. The [NiII8MI2] and [NiII8] clusters have the same topology of spin carriers, which display predominantly antiferromagnetic interactions to yield a diamagnetic ground state. The coupling within these octanuclear NiII clusters is rationalised in terms of the nature of the Ni‐O‐Ni angles within the core.
Discrete Cyanide‐Bridged Mixed‐Valence Co/Fe Complexes: Outer‐Sphere Redox Behaviour
Authors: Bernhardt Paul V. , Bozoglian Fernando , Macpherson Brendan P. , Martínez Manuel , González Gabriel , Sienra Beatriz
Published: June 2003

The outer‐sphere redox behaviour of a series of [LnCoIIINCFeII(CN)5]− (Ln = n‐membered pentadentate aza‐macrocycle) complexes have been studied as a function of pH and oxidising agent. All the dinuclear complexes show a double protonation process at pH ≈︁ 2 that produces a shift in their UV/Vis spectra. Oxidation of the different non‐protonated and diprotonated complexes has been carried out with peroxodisulfate, and of the non‐protonated complexes also with trisoxalatocobaltate(III). The results are in agreement with predictions from the Marcus theory. The oxidation of [Fe(phen)3]3+ and [IrCl6]2− is too fast to be measured, although for the latter the transient observation of the process has been achieved at pH = 0. The study of the kinetics of the outer‐sphere redox process, with the S2O82− and [Co(ox)3]3− oxidants, has been carried out as a function of pH, temperature, and pressure. As a whole, the values found for the activation volumes, entropies, and enthalpies are in the following margins, for the diprotonated and non‐protonated dinuclear complexes, respectively: ΔV≠ from 11 to 13 and 15 to 20 cm3 mol−1; ΔS≠ from 110 to 30 and −60 to −90 J K−1 mol−1; ΔH≠ from 115 to 80 and 50 to 65 kJ·mol−1. The thermal activation parameters are clearly dominated by the electrostriction occurring on outer‐sphere precursor formation, while the trends found for the values of the volume of activation indicate an important degree of tuning due to the charge distribution during the electron transfer process. The special arrangement on the amine ligands in the isomer trans‐[L14CoIIINCFeII(CN)5]− accounts for important differences in solvent‐assisted hydrogen bonding occurring within the outer‐sphere redox process, as has been established in redox reactions of similar compounds. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis and Electrical Properties of the Pr0.5+x−yBiyLi0.5−3xTiO3 System
Authors: Martínez‐Sarrión María‐Luisa , Mestres Lourdes , Herráiz Marta , Maqueda Oscar , Fernández Nestor , García Mario‐Fidel
Published: June 2003

The stoichiometry, polymorphism, and electrical behaviour of the solid solutions Pr0.5+x−yBiyLi0.5−3xTiO3 with perovskite‐like structure have been studied. Data are given as a solid solution triangle, XRD patterns for two polymorphs T and O, the composition dependence of their parameters, and ionic conductivity plots. A region of perovskite‐like solid solutions was obtained when the bismuth content in the general formula Pr0.5+x−yBiyLi0.5−3xTiO3 was y ⩽ 0.10 and the lithium content was 0.033 ⩽ x ⩽ 0.133. The compounds are mixed conductors. With increasing amounts of lithium the ionic conductivity first increased, reached a maximum for x = 0.20, with a conductivity at 25 °C of 6.639·10−3 S·cm−1, and then decreased. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Iron Complexes Containing the Ligand N,N′‐Bis(6‐methyl‐2‐pyridylmethyl)‐N,N′‐bis(2‐pyridylmethyl)ethane‐1,2‐diamine: Structural, Spectroscopic, and Electrochemical Studies, Reactivity with Hydrogen Peroxide and the Formation of a Low‐Spin Fe−OOH Complex
Authors: Balland Véronique , Banse Frédéric , Anxolabéhère‐Mallart Elodie , Nierlich Martine , Girerd Jean‐Jacques
Published: June 2003

The ligand N,N′‐bis(6‐methyl‐2‐pyridylmethyl)‐N,N′‐bis(2‐pyridylmethyl)ethane‐1,2‐diamine (L622M) has allowed to prepare the new FeII complex [(L622M)FeCl2] (1), and to compare its structural and spectroscopic characteristics with [(L622M)FeCl]PF6 (2). The molecular structure of 1, resolved by X‐ray diffraction, exhibits the ligand tetracoordinated with the two non‐methylated pyridine rings coordinated. As shown by UV/Vis spectroscopy and cyclic voltammetry, upon dissolution in methanol or acetonitrile, one chloride ion is released and replaced by a pyridine group. Therefore, complexes 1 and 2 adopt identical structures in solution, i.e. [(L622M)FeCl+. However, upon oxidation complex 1 gives several ferric complexes with the ligand L622M pentacoordinated, or tetracoordinated with two chloride ions. This peculiar behaviour is due to the presence of chloride ions in solution in the case of 1. Upon reaction with H2O2 in methanol, complex 2 leads to the formation of low‐spin [(L622M)FeIII(OOH)2+, whereas it is not observed in the case of 1. Based on the presence or not of chloride ions in solution, a mechanism is proposed for the reactivity of complexes 1 and 2 toward H2O2. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Neutral and Cationic [Bis(η1‐amidosilyl)‐η5‐cyclopentadienyl]titanium and ‐zirconium Complexes: Synthesis, X‐ray Molecular Structures and DFT Calculations
Authors: Cano Jesús , Royo Pascual , Jacobsen Heiko , Blacque Olivier , Berke Heinz , Herdtweck Eberhardt
Published: June 2003

Treatment of LiNHtBu with THF solutions of C5H4(SiMe2Cl)2gave C5H4(SiMe2NHtBu)2(1). Deprotonation of1with M(NMe2)4(M = Ti, Zr) under different conditions provided the monocyclopentadienyl complexes [M{η5‐C5H3[SiMe2(NHtBu)]2}(NMe2)3] [M = Ti (2), Zr (3)] and the single (η‐amidosilyl)cyclopentadienyl compounds [M{η5‐C5H3[SiMe2(NHtBu)][SiMe2(η1‐NtBu)]}(NMe2)2] [M = Ti (4), Zr (5)]. The related dibenzyl compounds [M{η5‐C5H3[SiMe2(NHtBu)][SiMe2(η1‐NtBu)]}(CH2Ph)2] [M = Ti (6), Zr (7)] resulted from treatment of1with M(CH2C6H5)4(M = Ti, Zr). Further deprotonation of the amido complexes4and5and the benzyl complexes6and7by heating in toluene solution gave the bis(η‐amidosilyl)cyclopentadienyl complexes [M{η5‐C5H3[SiMe2(η1‐NtBu)]2}(NMe2)] [M = Ti (8), Zr (9)] and [M{η5‐C5H3[SiMe2(η1‐NtBu)]2}(CH2Ph)] [M = Ti (10), Zr (11)], respectively. Treatment of the monobenzyl complexes10and11with B(C6F5)3yielded the cationic compounds [M{η5‐C5H3[SiMe2(η1‐NtBu)]2}]+as [(CH2Ph)B(C6F5)3]−[M = Ti (12), Zr (13)] salts. All new compounds were characterized by NMR spectroscopy, and the crystal structures of10and13were studied by diffraction methods. DFT calculations for the neutral and cationic species are described and provide an explanation for the unusual η1coordination of a phenyl ring to a group‐4 metal cation. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Assembly of Dicobalt(III) Complexes Incorporating Di‐μ‐thiophenolate Moieties
Authors: Marin‐Becerra Armando , Stenson Philip A. , McMaster Jonathan , Blake Alexander J. , Wilson Claire , Schröder Martin
Published: June 2003

The dinuclear [CoIIICoIII] complexes [Co2(L1)(μ‐OAc)(OAc)(NH3)](PF6)2 and [(Co2(L2)2(μ‐OAc)](PF6), incorporating the rare Co(μ‐SR)2Co moiety associated with Schiff‐base co‐ligands, are protected by bridging μ‐OAc− units situated within a domed cavity formed by the complexes; increasing the steric bulk of the ligand, as in [L3]2−, affords the mononuclear species [Co(L3)(OAc)]. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Synthesis, X‐ray Crystallographic and 1H NMR Spectroscopic Structural Studies on Cobalt(II) Complexes of Homoscorpionate, Heteroscorpionates and Chiral Tris(pyrazolyl)borates Obtained from 5(3)‐Isopropyl‐3(5)‐phenylpyrazole and 3,5‐Dimethylpyrazole
Authors: Ruman Tomasz , Ciunik Zbigniew , Wołowiec Stanislaw
Published: June 2003

Condensation of 5(3)‐isopropyl‐3(5)‐phenylpyrazole with sodium borohydride led to a mixture of tris(pyrazolyl)borate ligands (Tpx) − the homoscorpionate hydrotris(5‐isopropyl‐3‐phenylpyrazolyl)borate and the heteroscorpionates hydro(3‐isopropyl‐5‐phenylpyrazolyl)bis(5‐isopropyl‐3‐phenylpyrazolyl)borate and hydrobis(3‐isopropyl‐5‐phenylpyrazolyl)(5‐isopropyl‐3‐phenylpyrazolyl)borate − that were converted into TpxCo(NCS) complexes. The molecular structures of pentacoordinate[hydrotris(5‐isopropyl‐3‐phenylpyrazolyl)borato](tetrahydrofuran)(thiocyanato)cobalt(II) (1‐THF) and [hydrobis(3‐isopropyl‐5‐phenylpyrazolyl)(5‐isopropyl‐3‐cobalt(II) (3‐THF) were elucidated crystallographically. Hydro(3,5‐dimethylpyrazolyl)bis(5‐isopropyl‐3‐phenylpyrazolyl)borate was also obtained by condensation of 2.1 equiv. of 5(3)‐isopropyl‐3(5)‐phenylpyrazole and 0.9 equiv. of 3,5‐dimethylpyrazole with sodium borohydride, and it was converted into [hydro(3,5‐dimethylpyrazolyl)bis(5‐isopropyl‐3‐phenylpyrazolyl)borato](thiocyanato)cobalt(II) (4), which was characterized by X‐ray crystallography. The latter was converted thermally under mild conditions (358 K in toluene) into [hydro(3,5‐dimethylpyrazolyl)(3‐isopropyl‐5‐phenylpyrazolyl)(5‐isopropyl‐3‐phenylpyrazolyl)borato](thiocyanato)cobalt(II) (9) in 45% yield, as was concluded from the 1H NMR spectrum of the post‐reaction mixture. The dimer of 9 was obtained as single crystals from toluene/hexane and its structure was determined crystallographically. Two chiral Tpx ligands of opposite boron‐centered configurations are coordinated to cobalt(II) ions in a κ3 fashion. The pentacoordinate metal ions are bridged head‐to‐tail by the thiocyanate anions. This chiral Tpx ligand is the first example of a borate with fixed boron‐centered chirality. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)