bluuebunny/crossref_metadata_2025_split huggingface dataset:
Möbius sequence in children exposed in utero to misoprostol: Neuropathological study of three cases
Authors: Marques‐Dias Maria Joaquina , Gonzalez Claudette H. , Rosemberg Sergio 
Published: December 2003

AbstractBackgroundMisoprostol exposure in the first trimester of pregnancy has been related to congenital malformations, particularly the Möbius sequence and terminal transverse limb defects. CASES: Neuropathological findings of three patients with Möbius sequence related to misoprostol are reported. No previous pathological studies have shown these abnormalities to be associated with misoprostol exposure in utero. The brain stem was cut serially, from the rostral mesencephalum to the caudal aspect of the medulla, and all fragments were stained with hematoxylin‐eosin and cresyl violet. Old ischemic‐anoxic foci of gliosis, with necrosis and calcification, dorsally situated, were present from the pons to the medulla, involving some cranial nerve nuclei (especially the IV, VII, and XII) that were partially or completely depopulated of neural cells.CONCLUSIONSThe findings suggest a circulatory mechanism to the Möbius sequence, with vascular disruption involving the territory of the subclavian artery, occurring in a critical period of embryonic life between six to eight weeks postconception. These cases add further evidence of the role of misoprostol as a teratogen. Birth Defects Research (Part A) 67:000–000, 2003. © 2003 Wiley‐Liss, Inc.
Das Rezept als literarische Form. Zum multifunktionalen Gebrauch des Rezepts in der deutschen Literatur
Authors: Telle Joachim 
Published: December 2003

AbstractIn the medical writing of antiquity the recipe, a basic form of scientific writing, was considered a literary genre with conventions of its own. In texttype‐linguistics, however, the recipe plays only a minor role; in studies on the history of literary short texts it is hardly ever mentioned and, furthermore, it has come to the conclusion that the recipe's function has lain solely in the curing of the sick. The present study focuses on the its multifunctional character. A collection of widely scattered and hardly accessible recipes shows that the recipe adopted functions beyond giving technical directives. Its multifunctionality in the German literature of early modern times is manifest in medical and cooking jocular recipes, cooking recipes in minnesang, mock recipes aimed at physicians and astrologers, recipes of spiritual‐religious content, recipes containing art and literary criticism as well as recipes in a moral‐satirical or a political‐agitative vein.
Wem gehört Adam Smith? Gedanken zur Auseinandersetzung um das geistige Erbe des schottischen Philosophen und Ökonomen
Authors: Volkmann Laurenz 
Published: December 2003

AbstractSmith's appropriation by neoliberal theorists as the progenitor of economic liberalism and capitalism has recently been challenged by a phalanx of counter‐positions. In a concerted effort ‚to salvage the real Smith’︁, they rediscover the enlightenment philosopher who was very critical of ostentatious display of wealth and envisioned a society based on moral concerns rather than on the pursuit of self‐interest. This article discusses recent developments in the battle over the economist's and philosopher's heritage.
Experimental Design and Statistical Inference for Cluster Point Processes – with Applications to the Fruit Dispersion of Anemochorous Forest Trees
Authors: Näther W. , Wälder K. 
Published: December 2003

AbstractThis paper deals with experimental design and statistical inference for cluster point processes. The results are applied to fruit dispersion models of forest trees where the corresponding design of experiments is given by the positions of the traps containing the collected fruits. It is shown that consideration of anisotropic behaviour can lead to more realistic models. Modelling interactivity effects between trees seems to be of great interest. It is shown that an approach based on ordered weighted averages yields an notable improvement of model quality. The mathematical background of such models (Choquet integral, fuzzy measures) is sketched in the appendix. Finally, results for choosing a D‐optimal sub‐design are presented.
Direct and Indirect Classification in Clinical Research
Authors: Peters A. , Lausen B. 
Published: December 2003

AbstractWe investigate if the use of a priori knowledge allows an improvement of medical decision making. We compare two frameworks of classification – direct and indirect classification – with respect to different classification errors: differential misclassification, observed misclassification and true misclassification. We analyze general behaviors of the classifiers in an artificial example and furthermore as being interested in the diagnosis of early glaucoma we adapt a simulation model of the optic nerve head. Indirect classifiers outperform direct classifiers in certain parameter situations of a Monte‐Carlo study. In summary, we demonstrate that indirect classification provides a flexible framework to improve diagnostic rules by using explicit a priori knowledge in clinical research.
Blinded Sample Size Recalculation for Normally Distributed Outcomes Using Long‐ and Short‐term Data
Authors: Wüst K. , Kieser M. 
Published: December 2003

AbstractClinical trials are often planned with high uncertainty about the variance of the primary outcome variable. A poor estimate of the variance, however, may lead to an over‐ or underpowered study. In the internal pilot study design, the sample variance is calculated at an interim step and the sample size can be adjusted if necessary. The available recalculation procedures use the data of those patients for sample size recalculation that have already completed the study. In this article, we consider a variance estimator that takes into account both the data at the endpoint and at an intermediate point of the treatment phase. We derive asymptotic properties of this estimator and the relating sample size recalculation procedure. In a simulation study, the performance of the proposed approach is evaluated and compared with the procedure that uses only long‐term data. Simulation results demonstrate that the sample size resulting from the proposed procedure shows in general a smaller variability. At the same time, the Type I error rate is not inflated and the achieved power is close to the desired value.
Validation of Surrogate Markers in Multiple Randomized Clinical Trials with Repeated Measurements
Authors: Alonso Ariel , Geys Helena , Molenberghs Geert , Kenward Michael G. , Vangeneugden Tony 
Published: December 2003

AbstractPart of the recent literature on the validation of biomarkers as surrogate endpoints proposes to undertake the validation exercise in a multi‐trial context which led to a definition of validity in terms of the quality of both trial level and individual level association between the surrogate and the true endpoints (Buyse et al., 2000). These authors concentrated on continuous univariate responses. However, in many randomized clinical studies, repeated measurements are encountered on either or both endpoints. When both the surrogate and true endpoints are measured repeatedly over time, one is confronted with the modelling of bivariate longitudinal data. In this work, we show how such a joint model can be implemented in the context of surrogate marker validation. In addition, another challenge in this setting is the formulation of a simple and meaningful concept of “surrogacy”. We propose the use of a new measure, the so‐called variance reduction factor, to evaluate surrogacy at the trial and individual level. On the other hand, most of the work published in this area assume that only one potential surrogate is going to be evaluated. We also show that this concept will let us evaluate surrogacy when more than one surrogate variable is available for the analysis. The methodology is illustrated on data from a meta‐analysis of five clinical trials comparing antipsychotic agents for the treatment of chronic schizophrenia.
Measuring Differences of Trait Distributions Between Populations
Authors: Gregorius Hans‐Rolf , Gillet Elizabeth M. , Ziehe Martin 
Published: December 2003

AbstractA measure of difference between populations for a trait should reflect not only the differences in the relative frequencies of the trait states but also the trait differences between the states. Common approaches to measuring differences between populations rely on distance, probability, or variance concepts. To overcome conceptual problems of these approaches, a new difference measure Δ is presented that is based on both frequency and trait differences. For two populations, Δ expresses the degree to which the frequency distribution of the trait states within one population must be transformed in order to make it match the distribution in the other population. This is done by shifting the relative frequency excesses of trait states to other trait states of deficient frequency, where shifts occur between as similar states as possible. Δ equals the minimum sum of the shifted frequencies weighted by the respective trait differences. Its bounds are functions of the difference measure d0, which considers only differences in relative frequency. The computer program DeltaS applies an algorithm from operations research to calculate Δ. The effect of including trait differences is demonstrated by the topological differences observed between Δ‐ and d0‐dendrograms constructed from microsatellite allele frequencies in four riparian stands of black poplar (Populus nigra), where the trait difference between two alleles equals the difference in numbers of tandem repeats. Δ is applicable to all traits for which trait differences are measurable, and it is shown to have elementary linearity properties that considerably simplify its interpretation.
Bayesian Estimation of Hunting Success Rate and Harvest for Spatially Correlated Post‐stratified Data
Authors: Woodard R. , He C. Z. , Sun D. 
Published: December 2003

AbstractWe consider the estimation of success rate and harvest under post survey stratification at the sub‐domain (county) level. Often in this situation, the population size for the sub‐domain is unknown and the random mechanism that dictates the sample size for sub‐domains is ignored. Finding good estimators of success rate and harvest is very important for wildlife abundance. A Bayesian hierarchical model is developed to estimate both success rate and harvest simultaneously. The model includes a random sub‐domain sample size correlated with the number of successes in the sub‐domain, fixed week effects, random geographic effects, and spatial correlations between neighboring sub‐domains. The computation is done by Gibbs sampling and adaptive rejection sampling techniques. The method developed is illustrated using data from the Missouri Turkey Hunting Survey. The estimation of success rate is improved by treating the the sub‐domain sample size as a random variable instead of a fixed constant. The Bayesian model yields a reasonable harvest estimation. The spatial pattern of the estimated harvest matches the pattern of the check station data.
Kinetics of Aquation and Anation of Ruthenium(II) Arene Anticancer Complexes, Acidity and X‐ray Structures of Aqua Adducts
Authors: Wang Fuyi , Chen Haimei , Parsons Simon , Oswald Iain D. H. , Davidson James E. , Sadler Peter J. 
Published: December 2003

AbstractThe aqua adducts of the anticancer complexes [(η6‐X)Ru(en)Cl][PF6] (X=biphenyl (Bip) 1, X=5,8,9,10‐tetrahydroanthracene (THA) 2, X=9,10‐dihydroanthracene (DHA) 3; en=ethylenediamime) were separated by HPLC and characterised by mass spectrometry as the products of hydrolysis in water. The X‐ray structures of the aqua complexes [(η6‐X)Ru(en)Y][PF6]n, X=Bip, Y=0.5 H2O/0.5 OH, n=1.5 (4), X=THA, Y=0.5 H2O/0.5 OH, n=1.5 (5 A), X=THA, Y=H2O, n=2 (5 B), and X=DHA, Y=H2O, n=2 (6), are reported. In complex 4 there is a large propeller twist of 45° of the pendant phenyl ring with respect to the coordinated phenyl ring. Although the THA ligand in 5 A and 5 B is relatively flat, the DHA ring system in 6 is markedly bent (hinge bend ca. 35°) as in the chloro complex 3 (41°). The rates of aquation of 1–3 determined by UV/Vis spectroscopy at various ionic strengths and temperatures (1.23–2.59×10−3 s−1 at 298 K, I=0.1 M) are >20× faster than that of cisplatin. The reverse, anation reactions were very rapid on addition of 100 mM NaCl (a similar concentration to that in blood plasma). The aquation and anation reactions were about two times faster for the DHA and THA complexes compared to the biphenyl complex. The hydrolysis reactions appear to occur by an associative pathway. The pKa values of the aqua adducts were determined by 1H NMR spectroscopy as 7.71 for 4, 8.01 for 5 and 7.89 for 6. At physiologically‐relevant concentrations (0.5–5 μM) and temperature (310 K), the complexes will exist in blood plasma as >89 % chloro complex, whereas in the cell nucleus significant amounts (45–65 %) of the more reactive aqua adducts would be formed together with smaller amounts of the hydroxo complexes (9–25 %, pH 7.4, [Cl−]=4 mM).
A Functionalized Noncovalent Macrocyclic Multiporphyrin Assembly from a Dizinc(II) Bis‐Porphyrin Receptor and a Free‐Base Dipyridylporphyrin
Authors: Iengo Elisabetta , Zangrando Ennio , Alessio Enzo , Chambron Jean‐Claude , Heitz Valérie , Flamigni Lucia , Sauvage Jean‐Pierre 
Published: December 2003

AbstractThe bis‐porphyrin system ZnP2, in which two zinc porphyrins are connected by a phenanthroline linker in an oblique fashion, acts as a bifunctional receptor towards the complexation of free‐base meso‐5,10‐bis(4′‐pyridyl)‐15,20‐diphenylporphyrin (4′‐cis DPyP). In solution, NMR spectroscopy evidenced quantitative formation of the tris‐porphyrin macrocyclic assembly ZnP2(4′‐cis DPyP), in which the two fragments are held together by two axial 4′‐N(pyridyl)–Zn interactions. The remarkable stability of the edifice (an association constant of about 6×108 M−1 was determined by UV/Vis absorption and emission titration experiments in toluene) is due to the almost perfect geometrical match between the two interacting units. The macrocycle was crystallized and studied by X‐ray diffraction, which confirmed the excellent complementarity of the two components. Photoinduced energy transfer from the singlet excited state of the zinc porphyrin chromophores to the free‐base porphyrin occurs with an efficiency of 98 % (ken=2×1010 s−1 in toluene, ambient temperature) with a mechanism consistent with a dipole–dipole process with a low orientation factor.
Unique Guest‐Inclusion Properties of a Breathing Ionic Crystal of K3[Cr3O(OOCH)6(H2O)3][α‐SiW12O40]⋅16 H2O
Authors: Uchida Sayaka , Mizuno Noritaka 
Published: December 2003

AbstractA microstructured ionic crystal, K3[Cr3O(OOCH)6(H2O)3][α‐SiW12O40]⋅16 H2O (1) was synthesized by the complexation of the Keggin‐type polyoxometalate of [α‐SiW12O40]4− with a macrocation of [Cr3O(OOCH)6(H2O)3]+. Compound 1 possessed a straight channel, with an opening of approximately 0.5×0.8 nm, which contained the water of crystallization. The use of the macrocation with large size (0.7 nm) and small charge (+1) reduced the anion–cation interaction and was essential for the channel formation. The molecular structures of the polyoxometalate and the macrocation in 1 were retained under vacuum at 473 K. Analogues of 1 were synthesized with [α‐PVW11O40]4− or [Fe3O(OOCH)6(H2O)3]+. The water of crystallization in 1 was removed under vacuum at room temperature to form the closely packed guest‐free phase 2. Compound 2 reversibly and repeatedly included water and polar organic molecules with two carbon atoms or less. Guest inclusion was highly selective and a difference of even one methylene group in the organic guest molecule was discriminated by the host. Polar organic molecules with longer methylene chains and nonpolar molecules such as dinitrogen and methane were completely excluded. The guest‐inclusion properties could be explained by the ion–dipole interaction between the host and the guest, which is proportional to the dipole moment of the guest molecule and inversely proportional to the ion–dipole (host–guest) distance. Thus, small polar molecules were selectively absorbed. These distinctive guest‐inclusion properties were successfully applied to the oxidation of methanol from a mixture of C1 and C2 alcohols. These results show unique guest inclusion and catalysis by rationally designed ionic crystals.
2‐Phosphanylphenolate Nickel Catalysts for the Polymerization of Ethylene
Authors: Heinicke Joachim , Köhler Martin , Peulecke Normen , He Mengzhen , Kindermann Markus K. , Keim Wilhelm , Fink Gerhard 
Published: December 2003

AbstractThe previously unknown methallylnickel 2‐diorganophosphanylphenolates (RPh,cHex) were synthesized and found to catalyze the polymerization of ethylene. To explore the potential for ligand‐tuning, a variety of P‐alkyl‐ and P‐phenyl‐2‐phosphanylphenols was synthesized and allowed to react with [Ni(cod)2] (cod=1,5‐cyclooctadiene) or with NiBr2⋅DME and NaH. The complexes formed in situ with [Ni(cod)2] are generally active as ethylene polymerization catalysts with all the ligands tested, whereas the latter systems are inactive when 2‐dialkylphosphanylphenols are applied.Mwvalues, ranging from about 1000 to about 100 000 g mol−1, increase for various R2P groups in the order RPh<Et≈tBu<iPr<cHex, while aryloxy substituents usually diminish the molecular weights. Increasing basicity of P‐ or aryloxy substituents usually leads to increasing turnover numbers. The polymers are high density polyethylene (HDPE) with low methyl and sometimes low long‐chain branching. Investigation of the influence of the solvent shows that the catalysts are stabilized by some oxygen‐containing Lewis bases as well as by olefins. The catalysts are tolerant to water, in particular the 2‐dicyclohexylphosphanylphenolate nickel catalyst, which in THF–water (1:1) gives HDPE withMw=39 000,Mn=14 500 g mol−1. Additives of tetrahydrothiophene or pyridine do not inhibit the catalyst, but decrease the reaction rate and the molecular weight of the polymers.
Theoretical Study of Rhodium(I) Carbene Complexes: The Structural Versatility of Phosphino‐ Compared with Aminocarbenes
Authors: Miqueu Karinne , Despagnet‐Ayoub Emmanuelle , Dyer Philip W. , Bourissou Didier , Bertrand Guy 
Published: December 2003

AbstractDensity functional calculations are reported for complexes of general formula [(carbene)RhClL2] featuring model phosphino‐ and aminocarbenes. Both the cis and trans isomers of the rhodium(I) η1‐complexes (1–9) were investigated, and the influence of the rhodium co‐ligands (L=ethylene, phosphine, or carbon monoxide) was evaluated. In the case of phosphinocarbenes and carbon monoxide as a ligand, a somewhat unusual coordination mode was observed, in which a significant intramolecular Cl→Ccarbene interaction is present. The propensity of phosphino‐ and aminocarbenes to behave as four electron donors was also investigated both structurally and energetically on the related η2‐complexes 10–18. These results as a whole emphasize the structural versatility of phosphino‐ compared with aminocarbene complexes.
Design of Photoactivated DNA Oxidizing Agents: Synthesis and Study of Photophysical Properties and DNA Interactions of Novel Viologen‐Linked Acridines
Authors: Joseph Joshy , Eldho Nadukkudy V. , Ramaiah Danaboyina 
Published: December 2003

AbstractA new series of photoactivated DNA oxidizing agents in which an acridine moiety is covalently linked to viologen by an alkylidene spacer was synthesized, and their photophysical properties and interactions with DNA, including DNA cleaving properties, were investigated. The fluorescence quantum yields of the viologen‐linked acridines were found to be lower than that of the model compound 9‐methylacridine (MA). The changes in free energy for the electron transfer reactions were found to be favorable, and the fluorescence quenching observed in these systems is explained by an electron transfer mechanism. Intramolecular electron transfer rate constants were calculated from the observed fluorescence quantum yields and singlet lifetime of MA and are in the range from 1.06×1010 s−1 for 1 a (n=1) to 6×108 s−1 for 1 c (n=11), that is, the rate decreases with increasing spacer length. Nanosecond laser flash photolysis of these systems in aqueous solutions showed no transient absorption, but in the presence of guanosine or calf thymus DNA, transient absorption due to the reduced viologen radical cation was observed. Studies on DNA binding demonstrated that the viologen‐linked acridines bind effectively to DNA in both intercalative and electrostatic modes. Results of PM2 DNA cleavage studies indicate that, on photoexcitation, these molecules induce DNA damage that is sensitive to formamidopyrimidine DNA glycosylase. These viologen‐linked acridines are quite stable in aqueous solutions and oxidize DNA efficiently and hence can be useful as photoactivated DNA‐cleaving agents which function purely by the co‐sensitization mechanism.
Novel Podands and Macrocycles with Diacetal (Tetraoxadecalin) Cores: Synthesis, Structure, Stereochemistry and Cation Inclusion
Authors: Abramson Sarah , Ashkenazi Eli , Frische Klaus , Goldberg Israel , Golender Larisa , Greenwald Moshe , Lemcoff N. Gabriel , Madar Ravit , Weinman Sarah , Fuchs Benzion 
Published: December 2003

AbstractA series of functionalized 2,6‐dialkyl‐cis‐1,3,5,7‐tetraoxadecalin podands (3–10, alkyl = hydroxy‐, mesyloxy‐, halo‐, azido‐ and aminomethyl and ‐ethyl) were prepared, characterized, and used as precursors for a new and interesting class of macrocycles and cryptands (12–21), with the aim to use these as host–guest inclusion systems. Extensive spectroscopic work was performed, structural endorsement was obtained from X‐ray diffraction analyses and further insight into the structures was obtained from theoretical/computational studies. A number of macrocycles in the series exhibited good complexation with alkaline‐earth metal ions.
Quantitative Chirality Analysis of Molecular Subunits of Bis(oxazoline)copper(II) Complexes in Relation to Their Enantioselective Catalytic Activity
Authors: Alvarez Santiago , Schefzick Sabine , Lipkowitz Kenny , Avnir David 
Published: December 2003

AbstractThe analysis of the quantitative chirality of molecular subunits of spirocyclic bisoxazoline copper complexes was carried out in order to identify the molecular portions most responsible for the chirality of the whole molecule, and therefore also for its catalytic enantioselectivity. It is shown that the smallest fragment that carries the information on molecular chirality contains only a portion of the bidentate bisoxazoline ligands and most atoms of the two monodentate ligands. The structural parameters that are best correlated to the chirality measures of the studied systems are the bond angles at the bridgehead spiro‐carbon atom. A prediction is made for an analogous catalyst with potentially high enatioselectivity.