bluuebunny/crossref_metadata_2025_split huggingface dataset:
A predictive approach to selecting the size of a clinical trial, based on subjective clinical opinion
Authors: Spiegelhalter D. J. , Freedman L. S. 
Published: April 2007

AbstractThe ‘textbook’ approach to determining sample size in a clinical trial has some fundamental weaknesses which we discuss. We describe a new predictive method which takes account of prior clinical opinion about the treatment difference. The method adopts the point of clinical equivalence (determined by interviewing the clinical participants) as the null hypothesis. Decision rules at the end of the study are based on whether the interval estimate of the treatment difference (classical or Bayesian) includes the null hypothesis. The prior distribution is used to predict the probabilities of making the decisions to use one or other treatment or to reserve final judgement. It is recommended that sample size be chosen to control the predicted probability of the last of these decisions. An example is given from a multi‐centre trial of superficial bladder cancer.
Influence of Different ECM Mimetic Peptide Sequences Embedded in a Nonfouling Environment on the Specific Adhesion of Human‐Skin Keratinocytes and Fibroblasts on Deformable Substrates
Authors: Salber Jochen , Gräter Stefan , Harwardt Marc , Hofmann Matthias , Klee Doris , Dujic Jadranka , Jinghuan Huang , Ding Jiandong , Kippenberger Stefan , Bernd August , Groll Jürgen , Spatz Joachim P. , Möller Martin 
Published: April 2007

AbstractMechanical stress is a decisive factor for the differentiation, proliferation, and general behavior of cells. However, the specific signaling of mechanotransduction is not fully understood. One basic problem is the clear distinction between the different extracellular matrix (ECM) constituents that participate in cellular adhesion and their corresponding signaling pathways. Here, a system is proposed that enables mechanical stimulation of human‐skin‐derived keratinocytes and human dermal fibroblasts that specifically interact with peptide sequences immobilized on a non‐interacting but deformable substrate. The peptide sequences mimic fibronectin, laminin, and collagen type IV, three major components of the ECM. To achieve this, PDMS is activated using ammonia plasma and coated with star‐shaped isocyanate‐terminated poly(ethylene glycol)‐based prepolymers, which results in a functional coating that prevents unspecific cell adhesion. Specific cell adhesion is achieved by functionalization of the layers with the peptide sequences in different combinations. Moreover, a method that enables the decoration of deformable substrates with cell‐adhesion peptides in extremely defined nanostructures is presented. The distance and clustering of cell adhesion molecules below 100 nm has been demonstrated to be of utmost importance for cell adhesion. Thus we present a new toolbox that allows for the detailed analysis of the adhesion of human‐skin‐derived cells on structurally and biochemically decorated deformable substrates.
Kinetic evaluation in nonhuman primates of two new PET ligands for peripheral benzodiazepine receptors in brain
Authors: Imaizumi Masao , Briard Emmanuelle , Zoghbi Sami S. , Gourley Jonathan P. , Hong Jinsoo , Musachio John L. , Gladding Robert , Pike Victor W. , Innis Robert B. , Fujita Masahiro 
Published: April 2007

AbstractPeripheral benzodiazepine receptors (PBRs) are upregulated on activated microglia and are, thereby, biomarkers of cellular inflammation in brain. We recently developed two PET ligands with an aryloxyanilide structure to image PBRs and now evaluate the kinetics of these radiotracers in monkey to determine whether they are suitable to explore in human. Baseline and receptor‐blocking scans were performed with [11C]PBR01 and [18F]PBR06 in conjunction with serial measurements of the arterial plasma concentration of parent radiotracer separated from radiometabolite. We used brain and plasma data with compartmental modeling to calculate regional brain distribution volume, which is equal to the ratio at equilibrium of the concentration of radioligand in brain to that of plasma. The distribution volume of [11C]PBR01 was inaccurately estimated in the baseline scans, possibly because of the short half‐life of 11C or the presence of radiometabolite in brain. In contrast, the distribution volume of [18F]PBR06 was stably determined within 200 min of scanning, and nondisplaceable uptake was only ∼10% of total brain uptake. [18F]PBR06 is promising for use in human because brain activity could be quantified with standard compartmental models and showed higher ratios (∼10:1) of specific to nonspecific uptake. A critical factor for human use will be whether the tracer has adequately fast wash out from brain relative to the half‐life of the radionuclide to obtain stable values of distribution volume. Synapse 61:595–605, 2007. Published 2007 Wiley‐Liss, Inc.
In vitro and in vivo characterization of [3H]CNS‐5161—A use‐dependent ligand for the N‐methyl‐d‐aspartate receptor in rat brain
Authors: Biegon Anat , Gibbs Andrew , Alvarado Maritza , Ono Michele , Taylor Scott 
Published: April 2007

AbstractGlutamate is the major excitatory neurotransmitter in the brain. Glutamate activation of the N‐methyl‐d‐aspartate (NMDA) receptor subtype is thought to mediate important physiological and pathological processes, including memory formation and excitotoxicity. The goal of the present work was to characterize and validate a candidate agent for noninvasive positron emission tomography (PET) imaging of this receptor. [3H]‐labeled N‐[3‐3H]‐methyl‐3‐(thiomethylphenyl)cyanamide (CNS‐5161) was incubated with rat brain homogenates at increasing concentrations, temperatures, and times to establish the binding kinetics and affinity of the ligand in vitro. Nonspecific binding was measured with 100 μM MK‐801. The compound was also injected i.v. in rats pretreated with saline, NMDA, MK801, or a combination, and organ and brain regional uptake was assessed at various times after injection by autoradiography or dissection. Blood and brain samples were assayed for metabolites by high‐performance liquid chromatography. CNS‐5161 binds brain membranes with high affinity (Kd < 4 nM) and fast association and dissociation kinetics. Specific binding increased in the presence of glutamate and glycine. Intravenous administration in control rats resulted in a heterogeneous brain distribution with hippocampus and cortex ≫ thalamus ≫ striatum ≫ cerebellum, and a cortex/cerebellum ratio of 1.4. Pretreatment with NMDA increased the hippocampus‐to‐cerebellum ratio to 1.6–1.9 while MK801 abolished this increase, resulting in ratios close to 1. Thus, CNS‐5161 binds preferentially to the activated state of the NMDA receptor channel in vitro and in vivo. The high affinity and fast kinetics make it compatible with PET imaging of a carbon‐11 labeled CNS‐5161. Synapse 61:577–586, 2007. Published 2007 Wiley‐Liss, Inc.
Cocaine induces the expression of homer 1b/c, homer 3a/b, and hsp 27 proteins in rat cerebellum
Authors: Dietrich Jean‐Bernard , Arpin‐Bott Marie‐Pierre , Kao Dany , Dirrig‐Grosch Sylvie , Aunis Dominique , Zwiller Jean 
Published: April 2007

AbstractThe long homer proteins 1b/c, 2a/b, and 3a/b play an important role in postsynaptic neurons by clustering glutamate receptors and by coupling the receptors with various intracellular effectors. Using immunohistochemistry and Western‐blot analysis, this study shows that the expression of the long homer isoforms 1b/c and 3a/b was induced in rat cerebellum in response to cocaine administration. Acute treatment produced a very robust induction of both constitutive isoforms, whereas repeated treatment for 10 days induced a large expression of homer 1b/c and a more modest increase in the expression of the 3a/b isoform. The heat shock protein hsp 27 was also considerably induced in the cerebellum of cocaine‐treated rats, suggesting that it participates in assisting the correct folding of proteins, and by counteracting oxidative stress mechanisms triggered by the psychostimulant. In addition of being expressed in Purkinje neurons, homer 3a/b and hsp 27, but not homer 1b/c, were localized within Bergmann glial cells and in their extensions, which surround Purkinje cells, as assessed by coimmunoreactivity with glial fibrillary acidic protein. Cocaine was also found to induce both proteins in the Bergmann glial cells. Since we found that homer 3a/b colocalized with the mGluR1 receptor in Purkinje cells, the data suggest that the long homer isoforms are involved in the cocaine‐induced neuroplasticity that takes place in the cerebellum, by reshaping postsynaptic densities in Purkinje cell dendrites. Synapse 61:587–594, 2007. © 2007 Wiley‐Liss, Inc.
Clonal propagation in cashew (Anacardium occidentale): effect of rooting media on the rootability and sprouting of air‐layers
Authors: Aliyu OM 
Published: April 2007

AbstractAn evaluation of three different rooting media (topsoil, sawdust and river sand) mixed in different proportions for the rooting of cashew layers was carried out at the Cocoa Research Institute of Nigeria at Ibadan, southwestern Nigeria. Data were collected on percentage take, number of days to rooting, number of roots, root length and percentage sprouting, and were statistically analysed. Significant differences were recorded for the effects of medium, mixture proportion, genotype and medium × mixture proportion interaction, showing the strong influence of the rooting medium (and thus its composition – texture, nutrient status and water‐holding capacity) and the variation in genotypic response to rooting in cashew layers. Topsoil ranked best among the three media tested, and its combination with either sawdust or river sand in the ratio 1 : 1 (v/v) gave the best rooting and sprouting, thus suggesting its use as an effective rooting medium for cashew layering. Copyright © 2007 John Wiley & Sons, Ltd
The structure and function of Saccharomyces cerevisiae proteinase A
Authors: Parr Charity L. , Keates Robert A. B. , Bryksa Brian C. , Ogawa Masahiro , Yada Rickey Y. 
Published: April 2007

AbstractSaccharomyces cerevisiae proteinase A (saccharopepsin; EC 3.4.23.25) is a member of the aspartic proteinase superfamily (InterPro IPR001969), which are proteolytic enzymes distributed among a variety of organisms. Targeted to the vacuole as a zymogen, its activation at acidic pH can occur by two different pathways, a one‐step process to release mature proteinase A, involving the intervention of proteinase B, or a step‐wise pathway via the autoactivation product known as pseudo‐proteinase A. Once active, S. cerevisiae proteinase A is essential to the activities of other yeast vacuolar hydrolases, including proteinase B and carboxypeptidase Y. The mature enzyme is bilobal, with each lobe providing one of the two catalytically essential aspartic acid residues in the active site. The crystal structure of free proteinase A reveals that the flap loop assumes an atypical position, pointing directly into the S1 pocket of the enzyme. With regard to hydrolysis, proteinase A has a preference for hydrophobic residues with Phe, Leu or Glu at the P1 position and Phe, Ile, Leu or Ala at P1′, and is inhibited by IA3, a natural and highly specific inhibitor produced by S. cerevisiae. This review is the first comprehensive review of S. cerevisiae PrA. Copyright © 2007 John Wiley & Sons, Ltd.
New Series of Porous Ionic Crystals Constructed from Various Polyoxometalate Anions and Macrocations: Syntheses, Crystal Structures, and Comparison with Diverse Spatial Arrangement
Authors: Qu Xiaoshu , Xu Lin , Qiu Yunfeng , Gao Guanggang , Li Fengyan , Yang Yanyan 
Published: April 2007

AbstractA new series of ionic crystals, KH2[Cr3O(OOCCH3)6(H2O)3][α‐SiMo12O40] · 11 H2O (1), KH2[Cr3O(OOCCH3)6(H2O)3][α‐SiW12O40]μ·μ11H2O (2), K2[Cr3O(OOCCH3)6 (H2O)3][α‐PW12O40]μ· 17H2O (3), Na[Cr3O(OOCCH3)6(H2O)3]2[α‐PMo12O40] · 11H2O (4), H5[Cr3O(OOCCH3)6(H2O)3] [α‐P2Mo18O62] · 10H2O (5) based on a polyoxometalate building block with a macrocation, have been synthesized in aqueous solution and structurally characterized by single‐crystal X‐ray diffraction, IR spectra, elemental analysis, thermogravimetric analysis (TGA). The polyanions and macrocations stacked alternately through hydrogen bonds as well as electrostatic interactions to constitute a novel porous microstructure. In the crystal structures of 1, 2, and 3, oppositely charged cluster ions stacked alternately to form one‐dimensional channels. Compound 4 exhibits an unique structure that six macrocation pillars packed along the a‐axis to form a straight 1D channel, in which accommodates a polyoxometalate pillar. In compound 5, six α‐Dawson‐type polyoxometalate pillars stacked on top of each other along the a‐axis to form a straight 1D channel, which houses a macrocation pillar. The magnetic investigation on compounds 1 and 5 shows a typical antiferromagnetic interaction of the macrocation [Cr3O(OOCCH3)6(H2O)3]+, almost independent from the presence of polyoxometalate anions.
New Hexachalcogeno–Hypodiphosphates of the Alkali Metals: Synthesis, Crystal Structure and Vibrational Spectra of the Hexathiodiphosphate(IV) Hydrates K4[P2S6] · 4 H2O, Rb4[P2S6] · 6 H2O, and Cs4[P2S6] · 6 H2O
Authors: Gjikaj Mimoza , Ehrhardt Claus 
Published: April 2007

AbstractThe new hexathiodiphosphate(IV) hydrates K4[P2S6] · 4 H2O (1), Rb4[P2S6] · 6 H2O (2), and Cs4[P2S6] · 6 H2O (3) were synthesized by soft chemistry reactions from aqueous solutions of Na4[P2S6] · 6 H2O and the corresponding heavy alkali‐metal hydroxides. Their crystal structures were determined by single crystal X‐ray diffraction. K4[P2S6] · 4 H2O (1) crystallizes in the monoclinic space group P 21/n with a = 803.7(1), b = 1129.2(1), c = 896.6(1) pm, β = 94.09(1)°, Z = 2. Rb4[P2S6] · 6 H2O (2) crystallizes in the monoclinic space group P 21/c with a = 909.4(2), b = 1276.6(2), c = 914.9(2) pm, β = 114.34(2)°, Z = 2. Cs4[P2S6] · 6 H2O (3) crystallizes in the triclinic space group $P {\bar 1}$ with a = 742.9(2), b = 929.8(2), c = 936.8(2) pm, α = 95.65(2), β = 112.87(2), γ = 112.77(2)°, Z = 1. The structures are built up by discrete [P2S6]4− anions in staggered conformation, the corresponding alkali‐metal cations and water molecules. O ··· S and O ··· O hydrogen bonds between the [P2S6]4− anions and the water molecules consolidate the structures into a three‐dimensional network. The different water‐content compositions result by the corresponding alkali‐metal coordination polyhedra and by the prefered number of water molecules in their coordination sphere, respectively. The FT‐Raman and FT‐IR/FIR spectra of the title compounds have been recorded and interpreted, especially with respect to the [P2S6]4− group. The thermogravimetric analysis showed that K4[P2S6] · 4 H2O converted to K4[P2S6] as it was heated at 100 °C.
(HgBr2)3(As4S4)2: An Adduct of HgBr2 Molecules and Undistorted As4S4 Cages
Authors: Bräu Michael F. , Pfitzner Arno 
Published: April 2007

Abstract(HgBr2)3(As4S4)2 is obtained by high temperature reaction of stoichiometric amounts of HgBr2 and As4S4. It crystallizes in the monoclinic space group P21/c with the lattice constants a = 9.593(5) Å, b = 11.395(5) Å, c = 13.402(5) Å, β = 107.27(3)°, V = 1399(1) Å3, and Z = 2. The crystal structure consists of molecular units built from two undistorted As4S4 cages which are coordinated weakly by three almost linear HgBr2 units. Raman spectra clearly indicate minor bonding interactions between HgBr2 and As4S4.
Ge2Co6(CO)20: Ein Ge‐Co‐Cluster ausgehend von gelöstem GeBr
Authors: Schroeder Melanie , Schnepf Andreas 
Published: April 2007

AbstractGe2Co6(CO)20: A Ge‐Co Cluster Compound from Solubilized GeBrThe Ge‐Co cluster Ge2Co6(CO)20 is synthesized from a reaction of a GeBr solution with Co2(CO)8. Isolation of suitable crystals allows the determination of the crystal structure of Ge2Co6(CO)20, being the lacking member in the row GeCo4(CO)14 – Ge2Co6(CO)20 – Ge3Co8(CO)26.
Synthesis, Structure and Characterization of a Novel One‐dimensional Tube‐like Cadmium Coordination Polymer
Authors: Ding Bin , Li Jian , Yang En‐Cui , Wang Xiu‐Guang , Zhao Xiao‐Jun 
Published: April 2007

AbstractBy the self‐assembly of 2‐aminobenzimidazole (L), Nadca (Nadca = dicyanamide sodium) and CdCl2, a novel one‐dimensional (1D) CdII coordination polymer [Cd(μ1,5‐dca)(μ1,3,5‐dca)L]n (1) (L = 2‐aminobenzimidazole) has been synthesized and structurally characterized by single crystal X‐ray diffraction, element analysis and FT‐IR spectra. In 1 μ1,5‐bidentate and μ1,3,5‐tridentate dca ligands bridge CdII ions to form a 1D tube‐like structure, which presents a new 1D tubular structural motif of (3.4(2))(3(2).4(2).5(3)) topology in M‐dca systems (M = metallic). Solid‐state blue fluorescence spectrum of 1 also has been determined and compared with that of free ligand.
Phase Transition and Crystal Structure of the Monomeric Europium(II) Thiolate Eu(SC36H49)2
Authors: Angelkort Joachim , van Smaalen Sander , Hauber Sven Oliver , Niemeyer Mark 
Published: April 2007

AbstractSingle crystal X‐ray diffraction of Eu(SC36H49)2 has revealed a first order phase transition at a temperature of 119 K, that involves a reduction of the specific volume by 1 %. The transition corresponds to a doubling of the unit cell, as it is the result from reorientations of isopropyl groups that appear at peripheral sites of the organic ligands. It is argued that a denser packing is achieved at the expense of a less favourable conformation of one of the two crystallographically‐independent complexes in the low‐temperature phase. The Bond‐Valence method is used to show that interactions of equal strengths are present between europium and both sulphur atoms and both coordinating phenyl rings.
New Structure Type among Octahydrated Rare‐Earth Sulfates, β‐Ce2(SO4)3·8H2O, and a new Ce2(SO4)3·4H2O Polymorph
Authors: Casari Barbara M. , Langer Vratislav 
Published: April 2007

AbstractSyntheses, crystal structures and thermal behavior of two new hydrated cerium(III) sulfates are reported, Ce2(SO4)3·4H2O (I) and β‐Ce2(SO4)3·8H2O (II), both forming three‐dimensional networks. Compound I crystallizes in the space group P21/n. There are two non‐equivalent cerium atoms in the structure of I, one nine‐ and one ten‐fold coordinated to oxygen atoms. The cerium polyhedra are edge sharing, forming helically propagating chains, held together by sulfate groups. The structure is compact, all the sulfate groups are edge‐sharing with cerium polyhedra and one third of the oxygen atoms, belonging to sulfate groups, are in the S–Oμ3–Ce2 bonding mode. Compound II constitutes a new structure type among the octahydrated rare‐earth sulfates which belongs to the space group Pn. Each cerium atom is in contact with nine oxygen atoms, these belong to four water molecules, three corner sharing and one edge sharing sulfate groups. The crystal structure is built up by layers of [Ce(H2O)4(SO4)]nn+ held together by doubly edge sharing sulfate groups. The dehydration of II is a three step process, forming Ce2(SO4)3·5H2O, Ce2(SO4)3·4H2O and Ce2(SO4)3, respectively. During the oxidative decomposition of the anhydrous form, Ce2(SO4)3, into the final product CeO2, small amount of CeO(SO4) as an intermediate species was detected.
Synthesen und Strukturen von Bis(4,4′‐t‐butyl‐2,2′‐bipyridin)‐Ruthenium(II)‐Komplexen mit funktionellen Derivaten des Tetramethyl‐bibenzimidazols
Authors: Grüßing André , Rau Sven , Schebesta Sebastian , Scholz Alexander , Görls Helmar , Walther Dirk 
Published: April 2007

AbstractSyntheses and Structures of Bis(4,4′‐t‐butyl‐2,2′‐bipyridine) Ruthenium(II) Complexes with functional Derivatives of Tetramethyl‐bibenzimidazole[(tbbpy)2RuCl2] reacts with dinitro‐tetramethylbibenzimidazole (A) in DMF to form the complex [(tbbpy)2Ru(A)](PF6)2 (1a) (tbbpy: bis(4,4′‐t‐butyl)‐2,2′bipyridine). Exchange of the two PF6− anions by a mixture of tetrafluor‐terephthalat/tetrafluor‐terephthalic acid results in the formation of 1b in which an extended hydrogen‐bonded network is formed. According to the 1H NMR spectra and X‐ray analyses of both 1a and 1b, the two nitro groups of the bibenzimidazole ligand are situated at the periphery of the complex in cis position to each other. Reduction of the nitro groups in 1a with SnCl2/HCl results in the corresponding diamino complex 2 which is a useful starting product for further functionalization reactions. Substitution of the two amino groups in 2 by bromide or iodide via Sandmeyer reaction results in the crystalline complexes [(tbbpy)2Ru(C)](PF6)2 and [(tbbpy)2Ru(D)](PF6)2 (C: dibromo‐tetrabibenzimidazole, D: diiodo‐tetrabibenzimidazole). Furthermore, 2 readily reacts with 4‐t‐butyl‐salicylaldehyde or pyridine‐2‐carbaldehyde under formation of the corresponding Schiff base RuII complexes 5 and 6. 1H NMR spectra show that the substituents (NH2, Br, I, azomethines) in 2 ‐ 6 are also situated in peripheral positions, cis to each other. The solid state structure of both 2, and 3, determined by X‐ray analyses confirm this structure. In addition, the X‐ray diffraction analyses of single crystals of the complexes [(tri‐t‐butyl‐terpy)(Cl)Ru(A)] (7) and [(A)PtCl2] (8) display also that the nitro groups in these complexes are in a cis‐arrangement.
Diethylenetriammonium Aquapentachloroferrate(III) Chloride: Structure and Magnetic Properties
Authors: James Bruce D. , Mrozinski Jerzy , Klak Julia , Skelton Brian W. , White Allan H. 
Published: April 2007

AbstractDiethylenetriamine (dien) and iron(III) chloride in aqueous HCl yield (dienH3) [FeCl5(H2O)]Cl, in which the chloroferrate(III) anion is significantly distorted from octahedral symmetry due to the extensively hydrogen‐bonded lattice. On cooling, the high spin FeIII material shows weak antiferromagnetic coupling that results in a Néel temperature of 2.70 K.
Stabilizing the LaCoAl4 Structure through Indium‐Magnesium Substitution in CeRhIn4−xMgx (x = 0.79 and 0.84) – An Indide with Magnesium Centered Indium Cubes
Authors: Tuncel Selcan , Hoffmann Rolf‐Dieter , Pöttgen Rainer 
Published: April 2007

AbstractThe intermetallic compounds CeRhIn4−xMgx (x = 0.79 and 0.84) were prepared from the elements in sealed tantalum ampoules in a high‐frequency furnace. The samples were investigated by X‐ray powder and single crystal diffraction: LaCoAl4 type, Pmma, a = 829.5(2), b = 433.56(9), c = 740.2(2) pm, wR2 = 0.0458, 651 F2 values, 25 variables for CeRhIn3.21Mg0.79 and a = 831.44(10), b = 433.49(10), c = 741.04(10) pm, wR2 = 0.0543, 915 F2 values, 25 variables for CeRhIn3.16Mg0.84. The indium atoms build up two‐dimensional networks perpendicular to the b axis in an AA stacking sequence leaving slightly distorted trigonal, square and pentagonal prismatic voids for the rhodium, magnesium, and cerium atoms. Both square prismatic voids show small magnesium/indium mixing. The shortest interatomic distances occur for the Rh–Mg contacts (257 pm). Together, the rhodium, indium, and magnesium atoms build up three‐dimensional [RhIn4−xMgx] networks in which the cerium atoms fill distorted pentagonal channels.
Synthesis and Structure of Europium Aluminium Garnet (EAG)
Authors: Garskaite Editha , Sakirzanovas Simas , Kareiva Aivaras , Glaser Jochen , Meyer H.‐Jürgen 
Published: April 2007

AbstractEuropium aluminium garnet (Eu3Al5O12, EAG) was synthesized by an aqueous sol‐gel process and subsequent thermal annealing at 800 – 850 °C. Eu3Al5O12 crystallizes cubic (${\rm (} Ia \bar{\mathit 3} d, {\rm a = 12.140(1)\AA)}$ and its crystal structure was refined from X‐ray powder data. The refined oxygen position in the structure of EAG yields four shorter and four longer distances between europium and the eight surrounding oxygen atoms, forming a distorted dodecahedron. Pure Eu3Al5O12 can be treated at temperatures around 1000 °C before it converts into perovskite‐like EAP near 1300 °C.