bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of boosted regression trees (BRTs) and two‐step BRT procedures to model and predict blood‐brain barrier passage
Authors: Deconinck Eric , Zhang Menghui H. , Coomans Danny , Heyden Yvan Vander 
Published: July 2007

AbstractTwo new approaches, boosted regression trees (BRTs) and two‐step BRT, were evaluated for modelling and predicting the blood–brain barrier (BBB) passage of drugs. Classification and regression trees (CART) were used as a base learner in BRT. In two‐step BRT, a linear model (stepwise multiple linear regression (MLR) or partial least squares (PLS)) was built first, then BRT was applied to model the residuals of the linear model and both models were added. Both approaches were compared with the CART, MLR and PLS models. It was observed that BRT could improve the descriptive and predictive abilities compared to a single CART and that the stepwise MLR–BRT results in slightly improved descriptive and predictive properties compared to the MLR model. The combination of PLS and BRT did not result in an improvement, compared to the individual PLS model. The best models were obtained with stepwise MLR–BRT and PLS. It was shown that the combination of linear models with BRT is an approach that has potential and can be considered for future QSAR modelling. Copyright © 2007 John Wiley & Sons, Ltd.
Self‐Assembly Vesicles Made from a Cyclodextrin Supramolecular Complex
Authors: Jing Bo , Chen Xiao , Wang Xudong , Yang Chunjie , Xie Yizhou , Qiu Huayu 
Published: July 2007

AbstractSelf‐assembly vesicles have been made from a cyclodextrin (CD) supramolecular complex, which is cooperatively formed with natural β‐CD, 1‐naphthylammonium chloride (NA), and sodium bis(2‐ethyl‐1‐hexyl)sulfosuccinate (AOT) by weak noncovalent interactions. In the complex structure, a NA molecule is included inside a β‐CD molecule while it is coupled with an AOT molecule on one side. The supramolecular structure and morphology of the vesicles were characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively. The mechanism of vesicle formation and transition is discussed along with the data obtained from induced circular dichroism (ICD) and UV/visible spectroscopy, polarized optical microscopy (POM), and 1H NMR spectroscopy. Both the fabrication and the transition of vesicles are controlled by the inclusion equilibria and the cooperative binding of noncovalent interactions, which include the “key–lock” principle, electrostatic interactions, π–π stacking, and amphiphilic hydrophobic association.
In Situ and On‐Line Monitoring of Hydrodynamic Flow Profiles in Microfluidic Channels Based on Microelectrochemistry: Optimization of Channel Geometrical Parameters for Best Performance of Flow Profile Reconstruction
Authors: Amatore Christian , Klymenko Oleksiy V. , Oleinick Alexander , Svir Irina 
Published: July 2007

AbstractA theoretical approach for flow profile reconstruction in a rectangular microfluidic channel equipped with one or two microband electrodes working in generator–collector and generator–generator regimes was proposed by us previously (ChemPhysChem 2005, 6, 1581–1589; ChemPhysChem 2006, 7, 482–487). The purpose of the current study is to determine the ranges of dimensionless parameters corresponding to the highest sensitivity of the minimized functional to the shape of the flow profile. By application of a cubic spline to approximate the flow profile and analysis of the least‐squares functional, which can then be represented as a function of one variable, we derive the area of optimal method performance. Thus, mathematical confirmation of our previous theoretical physical predictions could be obtained.
Synthesis, Structure, and Reactivity of Diazoketiminato Complexes of Platinum(II) and Palladium(II): Cytotoxic Properties of a Platinum Complex
Authors: Lal Pratihar Jahar , Shee Biswaranjan , Pattanayak Poulami , Patra Debprasad , Bhattacharyya Arindam , Puranik Vedavati G. , Hung C. H. , Chattopadhyay Surajit 
Published: July 2007

AbstractReaction of the 2‐(arylazo)anilines Ar‐N=N‐C6H4NH2[HLnNH2; Ar = C6H5(HL1),p‐CH3C6H4(HL2),p‐ClC6H4(HL3)] with K2PtCl4in dmso affords the new PtIIazoimine complexes [(HLnNH)Pt(dmso)Cl] where the chloride and dmso ligands are mutuallycis. In contrast, treatment of Na2PdCl4with HLnNH2in dmso gives the chloro‐bridged palladium dimer [{(HLnNH)PdCl}2] as the major product along with [(HLnNH)2Pd] as the minor product. Further, the reaction of HLnNHCH2Ph with K2PtCl4in dmso also gives [(HLnNH)Pt(dmso)Cl] whereas Na2PdCl4affords the orthopalladated complexes [(LnNHCH2Ph)PdCl]. This means that the N–C(CH2Ph) bond is selectively cleaved by K2PtCl4. The reaction of [(HLnNH)Pt(dmso)Cl] with acetylacetone (acacH) gives the heteroleptic complex [(HLnNH)Pt(acac)]. [(HLnNH)Pt(dmso)Cl] and [(HLnNH)Pt(acac)] display a reversible reductive response at –1.20 and –1.46 V vs. SCE, respectively, in their cyclic voltammograms. The nature of the redox orbitals has been determined semi‐empirically employing the EHMO method. The cytotoxicity of [(HL1NH)Pt(dmso)Cl] has been examined with HeLa cells and the sub‐lethal dose (8 μM) determined by dose‐dependence studies. The relative degree of apoptotic and necrotic cell death using a sub‐lethal dose were measured by flow cytometry.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Synthesis and Characterization of DOTA‐(amide)4 Derivatives: Equilibrium and Kinetic Behavior of Their Lanthanide(III) Complexes
Authors: Pasha Azhar , Tircsó Gyula , Benyó Enikő Tircsóné , Brücher Ernő , Sherry A. Dean 
Published: July 2007

AbstractLanthanide complexes of tetraamide derivatives of DOTA are of interest today because of their application as chemical exchange saturation transfer (CEST) agents for magnetic resonance imaging (MRI). The protonation constants of some simple tetraamide derivatives of DOTA and the stability constants of the complexes formed with some endogenous metal ions, namely Mg2+, Ca2+, Cu2+, Zn2+, and lanthanide(III) ions, have been studied. These complexes were found to be considerably less stable than the corresponding [M(DOTA)]2– complexes, largely due to the lower basicity of the tetraamide ligands. The Mg2+ and Ca2+ complexes are well described by formation of only ML species at equilibrium while the Zn2+ and Cu2+ complexes exhibit one and two additional deprotonation steps above a pH of around 6, respectively. The extra deprotonation that occurs at high pH for the [Zn{DOTA‐(amide)4}]2+ complexes has been assigned to an amide deprotonation by 1H NMR spectroscopy. The first deprotonation step for the Cu2+ complexes was traced to formation of the ternary hydroxo complexes ML(OH) (by UV/Vis spectrophotometry) while the second step corresponds to deprotonation of an amide group to form ML(OH)H–1‐type complexes. The trends in the stability constants of the [Ln{DOTA‐(amide)4}]3+ complexes follow similar trends with respect to ion size as those reported previously for the corresponding [Ln(DOTA)]– complexes, but again, the stability constants are about 10–11 orders of magnitude lower. A kinetic analysis of complex formation has shown that complexes are directly formed between a Ln3+ cation and fully deprotonated L without formation of a protonated intermediate. [Ln{DOTA‐(MeAm)4}]3+ complex formation occurs at a rate that is two to three orders of magnitude slower than those of the corresponding [Ln(DOTA)]– complexes, while the variation in complex formation rates with Ln3+ ion size is opposite to that observed for the corresponding [Ln(DOTA)]– complexes. The Ce3+ and Eu3+ complexes of DOTA‐(MeAm)4 are kinetically inert with respect to acid‐catalyzed dissociation, which suggests that these complexes may potentially be safe for use in vivo. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
3D Architectures of InOOH: Ultrasonic‐Assisted Synthesis, Growth Mechanism, and Optical Properties
Authors: Chen Liyong , Ma Xuchu , Liu Yankuan , Zhang Yan'ge , Wang Weizhi , Liang Yi , Zhang Zude 
Published: July 2007

AbstractAn ultrasonic‐assisted solvothermal route based on the hydrolysis of In3+ was utilized to synthesize InOOH with a hierarchic three‐dimensional (3D) architecture, which was assembled by single‐crystalline nanowires with diameters of about 10 nm and lengths up to several hundred nanometers. X‐ray powder diffraction (XRD), field emission scanning electron microscopy (FE‐SEM), transmission electron microscopy (TEM), and FTIR spectra were used to characterize the obtained products. Alkaline media and solvent play crucial roles in influencing the phase and the morphology of the products. A possible mechanism was proposed to explain the formation process of the InOOH 3D nanostructure. The optical properties of InOOH was also investigated by ultraviolet and visible (UV/Vis) spectroscopy, which indicated that InOOH is a wide band‐gap semiconductor.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Charge‐Transfer Complexes between the Sulfur Molecules SO2, S2O, S3, SONH, and SOCl2 and the Amine Donors NH3 and NMe3 – A Theoretical Study
Authors: Steudel Ralf , Steudel Yana 
Published: July 2007

AbstractThe formation of adducts between the acceptor molecules SO2, S2O, S3, and SOCl2 and the donor molecules ammonia and trimethylamine has been studied by high‐level G3X(MP2) theory, in most cases for the first time. Minimum energy structures with a 1:1 composition and with sulfur–nitrogen bonds have been located for all complexes. The thermodynamic properties, vibrational spectra, and atomic charges of these molecules have been calculated. Of the 10 investigated complexes, only SO2·NMe3 (2) and S2O·NMe3 (4) are predicted to be thermodynamically stable in the gas phase under standard conditions (ΔG°298 < 0). However, all adducts except S3·NH3 (5), SOCl2·NH3 (7), and SOCl2·NMe3 (8) are stable thermodynamically at 77 K. In a polar continuum with a dielectric constant (ϵ) of 40, complexes 2, 4, and S3·NMe3 (6) are stable even at 25 °C. However, if the adducts are formed in the polar continuum from the gaseous components, all adducts except S3·NH3 are formed not only exothermally but also exergonically. Complexes 2, 4, and 8 are the only species known in the solid state so far. The charge transfer from donor to acceptor in the various complexes in the gas phase ranges from 0.08 to 0.39 electrostatic units and correlates inversely with the S–N bond length, which ranges from 198 to 295 pm. In general, the charge transfer weakens the bonds within the acceptor molecule, which therefore may be considered to become activated. The formation of thionyl imide (SONH) from SOCl2 and NH3 is exergonic in the gas phase and the interaction between SONH and NH3 is very weak. In the case of SO2, the 1:2 complexes SO2·2NH3 (1a) and SO2·2NMe3 (2a), which contain two S–N bonds, are unstable with respect to their three‐component molecules both in the gas phase and in a polar medium at 25 °C, but they are stable in the polar phase with respect to the gaseous components.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Preparation and Structure of Oligomeric Iodosylbenzene Sulfate (PhIO)3·SO3: Stable and Water‐Soluble Analog of Iodosylbenzene
Authors: Koposov Alexey Y. , Netzel Brian C. , Yusubov Mekhman S. , Nemykin Victor N. , Nazarenko Alexander Y. , Zhdankin Viktor V. 
Published: July 2007

AbstractNew phenyliodine(III) sulfate (PhIO)3·SO3, which has a complex polymeric structure of the trimeric iodosylbenzene units linked by sulfate anions, can be conveniently prepared by treatment of (diacetoxy)iodobenzene with sodium bisulfate in the presence of water. This sulfate can find practical application as a readily available, stable, and water‐soluble hypervalent iodine reagent with a reactivity pattern similar tothat of iodosylbenzene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Counterfactual thinking following negative outcomes: evidence for group and self‐protective biases
Authors: McCrea Sean M. 
Published: July 2007

AbstractDespite the robustness of self‐serving and group‐serving biases in attribution, there has been only limited evidence for these effects in counterfactual thinking. The present studies demonstrate that, following a negative outcome, individuals counterfactualize external factors relatively more than internal factors when they are identified with the target (i.e. ingroup members or the self) than when they are not. However, these effects are found only for external factors that are in some way disadvantageous to the target and could have led to the negative outcome. Implications of these findings for understanding the relationship between counterfactual thinking and judgments of causality, blame and affect are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Channel flow competence and sediment transport in upland streams in southeast Australia
Authors: Thompson Chris , Croke Jacky 
Published: July 2007

AbstractBedload transport data from planebed and step‐pool reach types are used to determine grain size transport thresholds for selected upland streams in southeast Australia. Morphological differences between the reach types allow the effects of frictional losses from bedforms, microtopography and bed packing to be incorporated into the dimensionless critical shear stress value. Local sediment transport data are also included in a regime model and applied to mountain streams, to investigate whether empirical data improve the delineation of reach types on the basis of dimensionless discharge per unit width (q*) and dimensionless bedload transport (qb*).Instrumented planebed and step‐pool sites are not competent to transport surface median grains (D50s) at bankfull discharge (Qbf). Application of a locally parametrized entrainment equation to the full range of reach types in the study area indicates that the majority of cascades, cascade‐pools, step‐pools and planebeds are also not competent at Qbf and require a 10 year recurrence interval flood to mobilize their D50s. Consequently, the hydraulic parameters of the regime diagram, which assume equilibrium conditions at bankfull, are ill suited to these streams and provide a poor basis of channel delineation. Modifying the diagram to better reflect the dominant transported bedload size (equivalent to the D16 of surface sediment) made only slight improvements to reach delineation and had greatest effect on the morphologies with smaller surface grain sizes such as forced pool‐riffles and planebeds. Likewise, the Corey shape factor was incorporated into the regime diagram as an objective method for adjusting a base dimensionless critical shear stress (τ*c50b) to account for lithologically controlled grain shape on bed packing and entrainment. However, it too provided only minor adjustments to reach type delineation. Copyright © 2007 John Wiley & Sons, Ltd.
Hillslope–channel sediment transfer in a slope failure event: Wet Swine Gill, Lake District, northern England
Authors: Johnson R. M. , Warburton J. , Mills A. J. 
Published: July 2007

AbstractThis paper describes and analyses a hillslope–channel slope failure event that occurred at Wet Swine Gill, Lake District, northern England. This comprised a hillslope slide (180 m3, c. 203 ± 36 t), which coupled with the adjacent stream, resulting in a channelized debris flow and fluvial flood. The timing of the event is constrained between January and March 2002. The hillslope failure occurred in response to a rainfall/snowmelt trigger, on ground recently disturbed by a heather moorland fire and modified by artificial drainage. Slide and flow dynamics are estimated using reconstructed velocity and discharge values along the sediment transfer path. There is a rapid downstream reduction in both maximum velocity, from 9·8 to 1·3 m s−1; and maximum discharge, ranging from 33·5 to 2·4 m3 s−1. A volumetric sediment budget quantified a high degree of coupling between the hillslope and immediate channel (∼92%: 167 m3), but virtually all of the sediment was retained in the first‐order tributary channel. Approximately 44% (81 m3) of the slide volume was retained in the run‐up deposit, and termination of the debris flow prior to the main river meant that the remainder did not discharge into the fluvial system downstream. These results suggest poor transmission of sediment to the main river at the time of the event, but importantly an increase in available material for post‐event sediment transfer processes within the small upland tributary. Copyright © 2007 John Wiley & Sons, Ltd.
The 6 and 12 month outcomes of older medical inpatients who recover from delirium
Authors: Cole Martin G. , You Yue , McCusker Jane , Ciampi Antonio , Belzile Eric 
Published: July 2007

AbstractObjectiveTo compare the 6 and 12 month outcomes of patients who recovered from delirium by 8 weeks with those who did not have an index episode.MethodsOlder medical inpatients were assessed for delirium using the Confusion Assessment Method. All patients with delirium and a sample of patients without delirium were enrolled. Recovery from delirium at 8 weeks was determined using the Delirium Index and an algorithm based on DSM‐III‐R criteria. The primary composite outcome was cognitive or functional decline, institutional residence or death at 6 and 12 months. We fitted two logistic regression models to predict outcome odds ratio (OR) of delirium‐recovered vs no delirium groups, adjusting for co‐morbidity, severity of physical illness and demographic variables. In secondary analyses, we examined each component of the primary outcome separately.ResultsOf 361 patients enrolled, 59 died, 33 withdrew and one was lost to follow‐up before 8 weeks. Of 268 patients assessed at 8 weeks, 115 and 95 were in delirium‐recovered and no delirium groups, respectively. The 6 month OR for the primary composite outcome was 0.89 (95% CI 0.46, 1.70); the 12 month OR was 1.5 (95% CI 0.77, 2.90). Secondary analyses revealed a clinically important increase in mortality at 6 and 12 months.ConclusionAmong patients who survived, there were no significant differences in cognition, function or institutional status between delirium‐recovered and no delirium groups at 6 and 12 months. If replicated, these findings have potentially important implications for clinical practice and research. Copyright © 2007 John Wiley & Sons, Ltd.
Hydrologic complexity and classification: a simple data reconstruction approach
Authors: Sivakumar B. , Jayawardena A. W. , Li W. K. 
Published: July 2007

AbstractTechnological advances, by facilitating extensive data collection, better data sharing, formulation of sophisticated methods, and development of complex models, have brought hydrologic research to a whole new level. Despite these obvious advances, there are also concerns about their general use in practice. On the one hand, it is natural to develop more complex models than perhaps needed (i.e. representations having too many parameters and requiring too much data); on the other hand, it is often difficult to ‘translate’ results from one specific situation to another. Recent studies have addressed these concerns, albeit in different forms, such as dominant processes, thresholds, model integration, and model simplification. A common aspect in some of these studies is that they recognize the need for a globally agreed upon ‘classification system’ in hydrology. The present study explores this classification issue further from a simple phase‐space data reconstruction perspective. The reconstruction involves representation of the given multidimensional hydrologic system using only an available single‐variable series through a delay coordinate procedure. The ‘extent of complexity’ of the system (defined especially in the context of variability of relevant data) is identified by the ‘region of attraction of trajectories’ in the phase space, which is then used to classify the system as potentially low‐, medium‐ or high‐dimensional. A host of river‐related data, representing different geographic and climatic regions, temporal scales, and processes, are studied. Yielding ‘attractors’ that range from ‘very clear’ ones to ‘very blurred’ ones, depending on data, the results indicate the usefulness of this simple reconstruction concept for studying hydrologic system complexity and classification. Copyright © 2007 John Wiley & Sons, Ltd.
Brn3 transcription factors control terminal osteoclastogenesis
Authors: Schulze‐Späte Ulrike , Battaglino Ricardo , Fu Jia , Sharma Anupriya , Vokes Martha , Stashenko Philip 
Published: July 2007

AbstractOsteoclastic bone resorption is a central mechanism in skeletal development, remodeling and pathology. RANKL is a mandatory factor controlling osteoclastogenesis; however, the underlying signaling pathways are only partially characterized. Using a screening array for the investigation of differential transcription factor activation, we identified activation of the Brn3 transcription factor family as a downstream event of RANKL signaling during terminal osteoclastogenesis. RANKL stimulation induces expression of Brn3a and b and maximal transcriptional activity of Brn3 family members concurrent with osteoclastic giant cell formation. Immunohistochemical analysis revealed both nuclear and cytoplasmic localization of Brn3a and b in mature osteoclasts. Functional inhibition of Brn3 transcription factors resulted in inhibition of pre‐osteoclast fusion and reduction in bone resorbing activity of mature osteoclasts. Furthermore, we identified synaptotagmin‐1, a regulator of membrane and vesicular fusion, as downstream target of Brn3 with a role in osteoclast function. We conclude that Brn‐3 represents a novel molecular differentiation factor that controls osteoclast maturation and function, suggesting an important role in bone metabolism. J. Cell. Biochem. 102: 1–12, 2007. © 2007 Wiley‐Liss, Inc.
Compartmentalization in membrane rafts defines a pool of N‐cadherin associated with catenins and not engaged in cell–cell junctions in melanoma cells
Authors: Rossier‐Pansier Laetitia , Baruthio Frédérique , Rüegg Curzio , Mariotti Agnese 
Published: July 2007

AbstractMelanoma progression is associated with changes in adhesion receptor expression, in particular upregulation of N‐cadherin which promotes melanoma cell survival and invasion. Plasma membrane lipid rafts contribute to the compartmentalization of signaling complexes thereby regulating their function, but how they may affect the properties of adhesion molecules remains elusive. In this study, we addressed the question whether lipid rafts in melanoma cells may contribute to the compartmentalization of N‐cadherin. We show that a fraction of N‐cadherin in a complex with catenins is associated with cholesterol/sphingolipid‐rich membrane microdomains in aggressive melanoma cells in vitro and experimental melanomas in vivo. Partitioning of N‐cadherin in membrane rafts is not modulated by growth factors and signaling pathways relevant to melanoma progression, is not necessary for cell–cell junctions' establishment or maintenance, and is not affected by cell–cell junctions' and actin cytoskeleton disruption. These results reveal that two independent pools of N‐cadherin exist on melanoma cell surface: one pool is independent of lipid rafts and is engaged in cell–cell junctions, while a second pool is localized in membrane rafts and does not participate in cell–cell adhesions. Targeting to membrane rafts may represent a previously unrecognized mechanism regulating N‐cadherin function in melanoma cells. J. Cell. Biochem. 103: 957–971, 2008. © 2007 Wiley‐Liss, Inc.