bluuebunny/crossref_metadata_2025_split huggingface dataset:
Organotin compounds: from kinetics to stereochemistry and antitumour activities
Authors: Gielen Marcel , Biesemans Monique , Willem Rudolph 
Published: March 2005

AbstractAn overview is given of the research performed by the authors at the Université Libre de Bruxelles and Vrije Universiteit Brussel, including the kinetics, stereochemistry and mechanism of SE2 reactions at a saturated carbon atom, the synthesis of chiral organotin compounds and their configurational and optical stability, the fluxionality of trigonal bipyramidal metal atoms and the stereochemistry of SN2 reactions at tetrahedrally substituted P, Si, Ge, Sn atoms, the cytotoxicity of many series of organotin compounds and the structure and reactivity of organotin salicylaldoximate clusters. Copyright © 2005 John Wiley & Sons, Ltd.
Structural characterization of dimethyl‐ and di‐n‐butyltin(IV) 2,3‐pyridinedicarboxylate in solution and in the solid state
Authors: García‐Zarracino Reyes , Höpfl Herbert 
Published: March 2005

AbstractPotassium 2,3‐pyridinedicarboxylate (K2pdc) has been reacted with dimethyl‐ and di‐n‐butyltin(IV) dichloride to give complexes with polymeric structures: [Me2Sn‐µ2‐pdc]n (1) and [nBu2Sn‐µ2‐pdc]n (2). IR, NMR (1H, 119Sn) spectroscopic and X‐ray crystallographic studies of 1 and 2 proved the expected 1:1 stoichiometric composition of the complexes. In solution compounds 1 and 2 have either cyclooligomeric or polymeric structures with a coordination number of 7 for the tin atoms. In polar solvents rapid exchange reactions of coordinated solvent molecules take place at the tin centers. In the solid state, polymeric helicoidal structures are found, in which one solvent molecule is coordinated to each tin atom. For 1 the DMSO adduct was characterized and, interestingly, in the case of 2 two different solid‐state structures having very similar three‐dimensional structures and crystal lattice parameters, but different solvent molecules coordinated to the tin atoms (H2O and MeOH), could be isolated. The solid‐state structures of 1‐DMSO, 2‐H2O and 2‐MeOH differ in the number of units required for a complete turn of the helix (two for 1‐DMSO, three for 2‐H2O and 2‐MeOH), which may be explained by the different steric requirements of the organic substituents at the tin centers (R = Me for 1‐DMSO, R = nBu for 2‐H2O and 2‐MeOH) and the fact that different solvent molecules are coordinated to them. In all three cases the crystal lattices contain small voids that are filled with either the backbones of the coordinated solvent molecules and/or disordered, uncoordinated solvent molecules. Copyright © 2005 John Wiley & Sons, Ltd.
Synthesis of chiral organotins suitable for the preparation of asymmetric heterogeneous catalysts
Authors: Faraoni M. Belén , Ayala Alicia D. , Vetere Virginia , Casella Mónica L. , Ferretti Osmar A. , Podestá Julio C. 
Published: March 2005

AbstractA key step in the preparation of asymmetric heterogeneous catalysts based on silica‐supported rhodium and platinum chemically modified with chiral organotins, is the synthesis of optically pure tin derivatives. We report on the synthetic pathways leading to the synthesis of (−)‐menthyltin derivatives without the formation of epimerization by‐products. The physical properties (including full 1H, 13C and 119Sn NMR spectra) of the new compounds, containing between one and three (−)‐menthyl ligands attached to the tin atom, are reported. The preparation of two catalysts based on silica‐supported rhodium and platinum chemically modified with (−)‐menthyldiphenylmethyltin, as well as some studies on the catalytic hydrogenation of ethyl pyruvate, are also described. These studies show that the reductions lead to (R)‐ and (S)‐ethyl lactates as the only products, that the (S) enantiomer was the isomer formed preferentially, and that the degree of conversion observed using both catalytic systems was almost quantitative (97–100%). The enantiomeric excesses observed were in the range 7–8%. One important advantage of these catalytic systems is their stability. Recycling of the used catalysts is possible, without any loss in the degree of conversion or enantiomeric excess. Copyright © 2005 John Wiley & Sons, Ltd.
Stereoselective Synthesis of Highly Enantioenriched (E)‐Allylsilanes by Palladium‐Catalyzed Intramolecular Bis‐Silylation: 1,3‐Chirality Transfer and Enantioenrichment via Dimer Formation
Authors: Suginome Michinori , Iwanami Taisuke , Ohmori Yutaka , Matsumoto Akira , Ito Yoshihiko 
Published: March 2005

AbstractHighly enantioenriched (E)‐allylsilanes have been synthesized from optically active allylic alcohols on the basis of Pd‐catalyzed intramolecular bis‐silylation followed by highly stereospecific SiO elimination reactions. The method involves three steps: 1) O‐disilanylation of the allylic alcohols with chlorodisilanes, 2) intramolecular bis‐silylation in the presence of a 1,1,3,3‐tetramethylbutyl isocyanide/[Pd(acac)2] (acac=acetylacetonate) catalyst at 110 °C, and 3) treatment of the reaction mixture with organolithium reagents. The overall transformation proceeds with nearly complete conservation of the enantiopurity of the starting allyl alcohols by transposition of the CC bond. For instance, (R)‐(E)‐3‐decen‐2‐ol (99.6–99.7 % ee) produced (S)‐(E)‐4‐(organosilyl)‐2‐decene of 98.8–99.4 % ee for a variety of silyl groups, including Me3Si, Me2PhSi, tBuMe2Si, Et3Si, and iPr3Si. In the bis‐silylation step, the initially formed trans‐1,2‐oxasiletanes immediately dimerize to stereoselectively give 1,5‐dioxa‐2,6‐disilacyclooctanes, which are isolated in high yield by carrying out the reaction at 70 °C. The eight‐membered ring compounds undergo thermal extrusion of (E)‐allylsilanes in high yield at 110 °C, along with formation of 1,3‐dioxa‐2,5‐disilacyclohexane derivatives. These in turn undergo a Peterson‐type elimination by treatment with nucleophiles such as BuLi and PhLi to give the (E)‐allylsilanes. All of the steps involved in the sequence proceed with extremely high stereoselectivity and stereospecificity, leading to almost complete 1,3‐chirality transfer through the overall transformation. The dimerization step, which forms diastereomeric intermediates, allows the synthesis of a highly enantioenriched allylsilane (99.4 % ee) from an optically active allylic alcohol with lower enantiopurity (79.2 % ee) by enrichment of enantiopurity. A general method for the determination of the enantiomeric excesses of (E)‐allylsilanes is also described in detail.
Preparative Manipulation of Gold Nanoparticles by Reversible Binding to a Polymeric Solid Support
Authors: Abed Ovadia , Vaskevich Alexander , Arad‐Yellin Rina , Shanzer Abraham , Rubinstein Israel 
Published: March 2005

AbstractA preparative scheme is presented for controlled modification of gold nanoparticles (NPs) by using reversible binding to a polymeric solid support through boronic acid chemistry. Octanethiol‐capped Au NPs were bound to a boronic acid functionalized resin by custom‐synthesized bifunctional linker molecules. The NPs were chemically released from the resin to the solution, with one (or a few) linker molecules embedded in their capping layer. This was confirmed by rebinding the linker‐derivatized NPs to a boronic resin, exploiting the reversibility of the boronic acid/diol chemistry. The same scheme was employed to demonstrate a new method for affinity separation of NPs by means of a solid‐phase reaction. The use of boronic acid provides versatility and chemical reversibility, while the polymeric solid support affords the separation and preparative aspects. The method presented here may be useful in various facets of NP handling, manipulation, and separation.
Sequestered Plutonium: [PuIV{5LIO(Me‐3,2‐HOPO)}2]—The First Structurally Characterized Plutonium Hydroxypyridonate Complex
Authors: Gorden Anne E. V. , Shuh David K. , Tiedemann Bryan E. F. , Wilson Richard E. , Xu Jide , Raymond Kenneth N. 
Published: March 2005

AbstractThe first single‐crystal X‐ray diffraction analysis of a hydroxypyridonate plutonium(IV) complex is presented, that of the tetradentate ligand 5LIO(Me‐3,2‐HOPO) with PuIV. The [PuIV{5LIO(Me‐3,2‐HOPO)}2] complex crystallizes in the space groupPna21with the asymmetric unit cell containing two unique eight‐coordinate plutonium complexes and one perchlorate anion. According to shape measure analysis, the geometry of both Pu centers is closest to a bicapped trigonal prism (C2vsymmetry, for Pu 1:S(C2v)=13.48°,S(D4d)=15.43°,S(D4d)=16.10°). The average bond length for the PuO(phenolic) is 2.31(4) Å, whereas the PuO(amide) distances are slightly longer, averaging 2.40(2) Å. The preparative chemistry of this compound and the implications of the structure are discussed.
Response and resistance in 300 patients with BCR‐ABL–positive leukemias treated with imatinib in a single center
Authors: Lahaye Tanja , Riehm Birte , Berger Ute , Paschka Peter , Müller Martin C. , Kreil Sebastian , Merx Kirsten , Schwindel Uwe , Schoch Claudia , Hehlmann Rüdiger , Hochhaus Andreas 
Published: March 2005

AbstractBACKGROUNDThe advent of imatinib has considerably changed the treatment of chronic myeloid leukemia (CML). Early studies demonstrated high rates of hematologic and cytogenetic responses in all phases of the disease after limited observation periods.METHODSThe authors evaluated long‐term outcome, rates of response, and resistance in 300 patients with BCR‐ABL–positive leukemias (CML in chronic phase after failure to respond to interferon‐alpha [CP], n = 139; accelerated phase [AP], n = 80; myeloid blast crisis [BC], n = 76; lymphoid BC and Philadelphia chromosome‐positive acute lymphoblastic leukemia, n = 5) who entered clinical trials with imatinib in a single center after an observation time of 4.5 years.RESULTSIn CP, hematologic remission was achieved in 97% and major (MCR) and complete cytogenetic remission (CCR) in 61% and 49% of patients, respectively. The chance to achieve MCR was higher in patients commencing imatinib earlier in the course of CML. In AP, the median survival period after the start of imatinib was 44 months, and MCR and CCR were observed in 31% and 26% of patients, respectively. In myeloid BC, the median survival period after the start of imatinib and after diagnosis of BC was 6 and 9 months, respectively. Hematologic resistance occurred in 25%, 41%, and 92% of patients in CP, AP, and myeloid BC, respectively, and was associated with BCR‐ABL mutations in 45% of patients and with clonal evolution in 58% of patients.CONCLUSIONSThe data emphasized the need for a prolonged follow‐up of patients treated with imatinib to define the clinical potential of the drug and to establish methods to optimize therapy. Cancer 2005. © 2005 American Cancer Society.
Rainfall monitoring systems over an urban area: the city of Rome
Authors: Russo Fabio , Napolitano Francesco , Gorgucci Eugenio 
Published: March 2005

AbstractIn small catchments a very high space–time rainfall resolution is needed in order to obtain, with sufficient accuracy, flash flood nowcasting as well as monitoring of sewer systems. In this light, a radar meteorology campaign was conducted during the fall of 2001, over the city of Rome (Italy), using measurements collected by the polarimetric Doppler radar Polar 55C located in the south‐east of the city at a distance of 15 km from the downtown and by a network consisting of 32 tipping bucket raingauges. A comparative analysis of the rainfall fields obtained using two interpolation methods (inverse‐distance and kriging) with those obtained using radar rainfall measurements was performed. The overall performance of the different methods was evaluated using objective functions. Errors depending on the gauge density were weighed by changing the number of raingauges considered in the reconstructed rainfall fields. Copyright © 2005 John Wiley & Sons, Ltd.
Uncertainty analysis of the influence of rainfall time resolution in the modelling of urban drainage systems
Authors: Aronica Giuseppe , Freni Gabriele , Oliveri Elisa 
Published: March 2005

AbstractIn urban drainage modelling, rainfall temporal variability can be considered as one of the most critical knowledge elements when dealing with rainfall–runoff models input data. The rainfall data temporal resolution usually available for practical applications is often lower than that requested for the rainfall–runoff simulation in urban areas, greatly compromising model accuracy. The present paper evaluates the influence of rainfall temporal resolution on the uncertainty of the response of rainfall–runoff modelling in urban environments.Analyses have been carried out using historical rainfall–discharge data collected for about 10 years in Parco d'Orleans experimental catchment (Palermo, Italy). The historical rainfall data have been taken as a reference rainfall, and resampled data have been obtained through a rescaling procedure with variable temporal windows. The shape comparison between ‘true’ and rescaled rainfall data has been carried out using a non‐dimensional performance index. Monte Carlo simulations have been carried out, applying two different rainfall–runoff models, using the recorded data and the resampled events. The results of the simulations were used to derive, for both models, the cumulative probabilities of peak discharges conditioned on the observation according to the GLUE (Generalized Likelihood Uncertainty Estimation) methodology. Copyright © 2005 John Wiley & Sons, Ltd.
The impact of tipping‐bucket raingauge measurement errors on design rainfall for urban‐scale applications
Authors: Molini A. , Lanza L. G. , La Barbera P. 
Published: March 2005

AbstractThe tipping‐bucket rain gauge is known to underestimate rainfall at high intensities because of the rain water amount that is lost during the tipping movement of the bucket. The related biases are known as systematic mechanical errors and, since their effect increases with rain intensity, have a significant influence on the derived statistics of rainfall extremes. A correction procedure for rain intensity data sets is proposed in this paper based on the dynamic calibration of the gauge at both fine and coarse resolution, either in direct form or after proper downscaling of the available figures. The effect of systematic mechanical errors on the assessment of design rainfall for urban‐scale applications is quantified based on two rain‐rate data sets recorded at very different resolutions in time. A random cascade downscaling algorithm is used for the processing of coarse‐resolution data so that correction can be applied at suitable time scales. The resulting depth–duration–frequency curves obtained from the original and corrected data sets are used to quantify the impact of uncorrected rain‐intensity measurements on design rainfall and the related statistical parameters. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of urbanization on the diurnal rainfall pattern in Houston
Authors: Burian Steven J. , Shepherd J. Marshall 
Published: March 2005

AbstractData from 19 raingauges located within and nearby Houston were analysed to quantify the impact of urbanization of the Houston metropolitan area on the local diurnal rainfall pattern. The average annual and warm‐season diurnal rainfall patterns were determined for one time period when Houston was relatively small and likely would not have had a significant effect on meteorological processes (1940–58) and for a second, more recent, time period after Houston had become a major metropolitan area (1984–99). The diurnal rainfall patterns within the hypothesized urban‐affected region and an upwind control region were compared for the pre‐ and post‐urban time periods. Results indicated that the diurnal rainfall distribution in the urban area is much different than that found for the upwind and downwind adjacent regions for the 1984 to 1999 time period. For an average warm season from 1984 to 1999, the urban area and downwind urban‐impacted region registered 59% and 30% respectively greater rainfall amounts from noon to midnight than an upwind control region. Moreover, the urban area had approximately 80% more recorded rainfall occurrences between noon and midnight during the warm season than surrounding areas. Comparison of the pre‐ and post‐urban rainfall patterns indicated that the diurnal rainfall distribution has changed in southeast Texas. The changes are most significant in the urban area, especially for the afternoon time increments during the warm season. The average warm‐season rainfall amount registered in the urban area increased by 25% from the pre‐ to the post‐urban time period, while the amount in the upwind control region decreased by 8%. The majority of the increase was observed for the noon to 4 p.m. and 4 p.m. to 8 p.m. time increments. Copyright © 2005 John Wiley & Sons, Ltd.
Irregular elliptic surfaces of degree 12 in projective fourspace
Authors: Abo Hirotachi , Ranestad Kristian 
Published: March 2005

AbstractSo far a few families of smooth irregular surfaces are known to exist in ℙ4 up to pullbacks by suitable finite morphisms from ℙ4 onto ℙ4 itself. In this paper we present two different constructions of irregular smooth minimal elliptic surfaces of degree 12 in ℙ4. The first is a monad construction while the other uses liaison. The family constructed via liaison includes the surfaces of the first family as a special case. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the boundedness of some potential‐type operators with oscillating kernels
Authors: Karasev Denis N. , Nogin Vladimir A. 
Published: March 2005

AbstractWe consider a class of multidimensional potential‐type operators with kernels that have singularities at the origin and on the unit sphere and that are oscillating at infinity. We describe some convex sets in the (1/p, 1/q)‐plane for which these operators are bounded from Lp into Lq and indicate domains where they are not bounded. We also reveal some effects which show that oscillation and singularities of the kernels may strongly influence on the picture of boundedness of the operators under consideration. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Maximality properties for isometric interpolating sequences and sequences of trivial points in the spectrum of H∞
Authors: Mortini Raymond 
Published: March 2005

AbstractLet (xn) be an isometric interpolating sequence or a sequence of trivial points in the spectrum of H∞. It is shown that either every cluster point of that sequence has a maximal support set or there exists y ∈ M(H∞+C) such that the support of xn is contained in the support of y for infinitely many n. Similar results for Gleason parts are obtained, too. We also investigate the H∞‐convex hulls of countable unions of support sets and show that whenever supp x ⊂ supp y and x /∈ $ \overline {P(y)} $, then the H∞‐convex hull of supp x does not meet $ \overline {P(y)} $. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Capillary electrophoresis–mass spectrometry as a powerful tool in clinical diagnosis and biomarker discovery
Authors: Kolch Walter , Neusüß Christian , Pelzing Matthias , Mischak Harald 
Published: March 2005

AbstractProteome analysis is now emerging as key technology for deciphering biological processes and the discovery of biomarkers for diseases from tissues and body fluids. The complexity and wide dynamic range of protein expression poses a formidable challenge to both peptide separation technologies and mass spectrometry (MS). Here we review the efforts that have been undertaken to date, focussing on capillary electrophoresis coupled to mass spectrometry (CE‐MS). We discuss CE‐MS from an application point of view evaluating its merits and vices in regard to biomarker discovery and clinical applications. As examples, we present the use of CE‐MS for the determination of protein patterns in urine, serum, and other body fluids. Finally, the benefits and limitations of CE‐MS for the analysis of proteins in clinical samples are discussed against the background of alternative technologies. © 2005 Wiley Periodicals, Inc., Mass Spec Rev 24:959–977, 2005
Non‐movement disorder heralds symptoms of Machado‐Joseph disease years before ataxia
Authors: D'Abreu Anelyssa , Friedman Joseph , Coskun Jim 
Published: March 2005

AbstractWe describe three patients with the Machado‐Joseph disease (MJD) genetic abnormality who had non‐movement disorder neurological symptoms or signs that preceded the gait ataxia by several years. This implies that some clinical manifestations other than ataxia may be considered part of the herald symptoms of MJD, especially in the setting of a positive family history. © 2005 Movement Disorder Society
Nonlinear random vibrations of a rotating shaft
Authors: Dimentberg M.F. 
Published: March 2005

AbstractBending vibrations of a rotating shaft due to external random excitation are considered for the case of potential instability of the shaft's linear model due to presence of internal or “rotating” damping. A two‐degree‐of‐freedom model with nonlinear elastic restoring forces is studied. An explicit expression is obtained for a stationary joint probability density of displacements and velocities as an exact analytical solution to the corresponding Fokker‐Planck‐Kolmogorov equation. The results are used to develop criterion for on‐line detection of instability for the operating shaft from its measured response.
Elastic‐plastic analysis of annular disks with nonlinear strain‐hardening under external pressure
Authors: You X.Y. , You L.H. , Zhang J.J. 
Published: March 2005

AbstractIn this paper, a simple and effective method is presented to deal with elastic‐plastic problems of annular disks with a nonlinear strain‐hardening material behaviour under external pressure. The governing equation is derived from the deformation theory of plasticity, von Mises' yield criterion, and the nonlinear strain‐hardening stress‐strain relation. The truncated Taylor's expansion is employed to solve the governing equation. A comparison is made among the proposed method, existing analytical approaches and finite element method for annular disks with constant and variable thickness under external pressure. Excellent agreement is found between the proposed approach and finite element analysis.
The preventive and therapeutic effects of two school mental health programs
Authors: Glidewell John C. , Gildea Margaret C. -L. , Kaufman Mildred K. 
Published: March 2005

AbstractIn 30 classrooms randomly assigned to experimental conditions, effects on mothers' reports of behavior symptoms were compared for (a) a parent education program; (b) an in‐school program of consultation, counseling, training, and referral; and (c) control classrooms. A sample of 426 families were followed for 30 months from the child's entry into third grade. A simple unweighted count of the number of symptoms reported in a home interview had adequate validity, good reliability, low reactivity, and intrinsic significance. Both programs had significant preventive and therapeutic effects on boys but not on girls. Effects were immediate in the upper middle class families, delayed in the lower class families.
An assessment of the dimensionality of moos' social climate scale
Authors: Wilkinson Leland 
Published: March 2005

AbstractA revised form of the Social Climate Scale (SCS) containing nine of the 14 subscales was given to 145 staff and 143 boys at a state training school for delinquents. A first principal factor was extracted from the item‐correlation matrices for staff and boys, respectively. This factor was named Value, because of its representation of an evaluative item dimension. A factor model was used to test whether this Value factor might account for the significant subscale intercorrelations found in these samples. Maximum likelihood factor analysis of the subscale correlation matrices for both groups provided the test for this model. Through a least‐squares rotation procedure on the maximum likelihood factor loadings, the Value factor was identified as the source of most of the subscale dependence. Implications for validation of the SCS and other related questionnaires by Moos are discussed.