bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sulfide anion interaction with Cu(1 0 0) and Cu modified Au(1 0 0): An electrochemical STM study
Authors: Schlaup Christian , Spaenig Alexander , Broekmann Peter , Wandelt Klaus 
Published: December 2009

AbstractWe describe the formation of thin copper sulfide semiconductor films under electrochemical conditions. In a first step we investigated the fundamental interaction of the Cu(1 0 0) surface with a sulfide anions containing electrolyte. Beside the classical p(2 × 2)‐S and c(2 × 6)‐S adlayer phases we found the formation of a closer packed “pseudo‐c(2 × 2)”‐S phase accompanied by an expansion of the topmost copper layer. For a further investigation of this “pseudo‐c(2 × 2)”‐S phase, we switched from the bulk Cu(1 0 0) electrode to a copper monolayer on a Au(1 0 0) electrode, which can be easily prepard using copper underpotential deposition. Since such a copper monolayer is pseudomorphic to the Au(1 0 0) surface and therefore expanded by 12.5% with respect to the bulk Cu(1 0 0)‐plane, exclusively a commensurate c(2 × 2)‐S structure is instantaneously formed and remains stable over a wide potential range.
Charge spectroscopy of Si nanocrystals in a SiO2 matrix [Phys. Status Solidi C 6, No. 12, 2704–2706 (2009)]
Authors: Antonova Irina , Neustroev Efim , Smagulova Svetlana , Jedrzejewski Jedrzej , Balberg Isaac 
Published: December 2009

AbstractDue to a regrettable error during the production process the author's list contains an error. The corrected list of authors with the assignment to the affiliations is as follows:Irina Antonova1, Efim Neustroev2, Svetlana Smagulova2, Jedrzej Jedrzejewski3, and Isaac Balberg31 Institute of Semiconductor Physics, SB RAS, 630090, Lavrentieva 13, Novosibirsk, Russia2 Yakutsk state University, Yakutsk, Russia3 The Racah Institute of Physics, The Hebrew University, Jerusalem, Israel
A panel study to evaluate quality of life assessments in patients suffering from allergic rhinitis after treatment with a Chinese herbal nasal drop
Authors: Chui Shiu Hon , Shek Siu Lam , Fong Ming Yiu , Szeto Yim Tong , Chan Kelvin 
Published: December 2009

AbstractAllergic rhinitis impairs quality of life (QOL). To assess the changes in QOL of patients with perennial allergic rhinitis (PAR) after treatment with Allergic Rhinitis Nose Drops (ARND), 35 patients were divided into 2 groups in a randomized, double‐blinded and placebo‐controlled study, with a cross‐over arrangement over 7 weeks, applying ARND or placebo. Group A (n = 20) started with ARND first for 2 weeks followed by a 3‐week washout before placebo for the last 2 weeks, while Group B (n = 15) started with placebo first and finished with ARND after washout. The changes in Clinical Symptoms Score (CSS) and QOL were observed. A decrease in CSS was observed in patients of both groups after treatment with ARND, but no change was observed with the placebo. Group A patients also showed significant improvements in complexion and sleep (P < 0.05 for both) after treatment with ARND, but no change with the placebo. Group B patients showed significant improvements in appetite and digestion (P < 0.01) as well as joy (P < 0.05) after cross‐over treatment with ARND, but no change with the placebo. ARND may have a therapeutic effect by relieving clinical symptoms and improving the QOL in patients with PAR. Copyright © 2009 John Wiley & Sons, Ltd.
Application of Computational Chemistry in Characterization of Solid Phase Microextraction Fibers for Selective Sorption of Drugs
Authors: Nowaczyk Alicja , Nowaczyk Jacek , Ligor Tomasz , Buszewski Bogusław 
Published: December 2009

AbstractThe solid phase microextraction fibers covered with polypyrrole obtained via a new way of electrochemical synthesis were characterized and studied in selective sorption of drugs.
Quantitative Structure Activity Relationship Analysis of Dicationic Diphenylisoxazole as Potent Anti‐Trypanosomal Agents
Authors: Paliwal Sarvesh , Narayan Ankita , Paliwal Shailendra 
Published: December 2009

AbstractThe chemotherapy of African trypanosomiasis currently centers on only small numbers of drugs, most of which were discovered more than forty years ago and are plagued by various problems ranging from poor oral absorption, acute toxicities, short duration of action and uncertainty about the mechanism of action. In quest of possible ways to understand the structural requirement for anti‐trypanosomal activity we found that QSAR analysis can be powerful tool for the design of new novel chemical entities with enhanced inhibitory potencies against Trypanosome brucei rhodesiense. In view of this QSAR analysis was performed using TSAR 3D version 3.3 software on series of 43 dicationic 3, 5‐diphenylisoxazoles derivatives. More than 200 physicochemical and topological descriptors were calculated and examined. Out of these descriptors statistically significant descriptors were selected by applying data reduction. Several statistical expressions were developed using stepwise multiple linear regression analysis (MLR) and partial least squares (PLS). The best MLR model showed good correlative and predictive ability with r=0.94, r2=0.88 and r$\rm{ {_{cv}^{2}}}$=0.84 and a comparable PLS model with r$\rm{ {_{cv}^{2}}}$=0.84 was obtained. The developed model was further validated by leave‐one‐out method of cross‐validation and prediction of test set. The study indicates that the anti‐trypanosomal activity is largely explained by cosmic energy, log P and total lipole descriptors. The QSAR study reported in present study provides important structural insights, related to anti‐trypanosomal activity.
Pharmacophore Guided 3D‐QSAR CoMFA Analysis of Amino Substituted Nitrogen Heterocycle Ureas as KDR Inhibitors
Authors: Lu Xiaoyun , Chen Yadong , You Qidong 
Published: December 2009

AbstractVascular endothelial growth factor‐2 receptors (VEGR‐2) or kinase insertdomain receptor (KDR) is a promising target for the development of novel anticancer drugs. To understand the structural basis for KDR inhibitory activity, 3D‐QSAR study using CoMFA analysis was performed on a set of amino substituted nitrogen heterocyclic urea derivatives. Due to the flexibility and structural diversity of investigated derivatives, we applied pharmacophore based alignment to construct reliable 3D‐QSAR models. The pharmacophore model was generated based on the verified docked conformation of compound 2 with KDR crystal structure using LigandScout 2.0 software. The constructed CoMFA model produced reasonable statistics, with $\rm{r_{{\rm{cv}}}^2 }$=0.507 and conventional r2=0.982. The predictive power of the developed model was obtained using a test set of 16 molecules, giving predictive correlation coefficient of 0.540. Molecular modeling and CoMFA contour analysis were performed to obtain useful information about the structural requirements for the KDR inhibitors which could be utilized in its future design.
Understanding the Aquatic Toxicity of Pesticide: Structure‐Activity Relationship and Molecular Descriptors to Distinguish the Ratings of Toxicity
Authors: Wang Gaoxue , Li Yan , Liu Xiaolin , Wang Yonghua 
Published: December 2009

AbstractThe purpose of this work is to develop robust, interpretable structure‐activity relationship (SAR) models for assessing the aquatic toxicity of pesticides. A data set of 1600 chemicals involving 533 nontoxic (C0), 287 slightly toxic (C1), 329 moderately toxic (C2), 231 highly toxic (C3), and 220 very highly toxic compounds (C4) to aquatic organisms were collected in this work. Their chemical structures were encoded into 196 molecular descriptors including the 2D topological, electrotopological state variables as well as the MlogP and AlogP parameters. Two variable selection techniques, i.e., the Stepwise procedure and the Genetic Algorithms (GA), coupled with the linear discriminant analysis (LDA) were used to obtain stable and thoroughly validated QSARs. Our results reveal that the AlogP is capable of classifying the C0 versus C4 compounds with an accuracy rate of 70.4%, but is poor between other groups, while the MlogP does not show any pronounced correlation for aquatic toxicity for all the groups. By using all the theoretical descriptors, the GA‐LDA models for C(0,4) C(1,3), C(1,4), and C(2,4) classifications are acceptable with external prediction accuracies ranging from 66.3% to 80.6%. All these selected descriptors accounting for the molecular size, electrotopological state, and hydrophobicity were found to be crucial to modeling the aquatic toxicity. The robustness and the predictive performance of the proposed models were verified using both the internal (cross‐validation by leave‐one out, Y‐scrambling) and external statistical validations (randomly selected). Our results demonstrate that the Genetic Algorithms have a huge advantage over the Stepwise procedure for generating more reliable models, but by using much less descriptors for all the data sets.
Multi‐Objective Feature Selection in QSAR Using a Machine Learning Approach
Authors: Soto Axel J. , Cecchini Rocío L. , Vazquez Gustavo E. , Ponzoni Ignacio 
Published: December 2009

AbstractThe selection of descriptor subsets for QSAR/QSPR is a hard combinatorial problem that requires the evaluation of complex relationships in order to assess the relevance of the selected subsets. In this paper, we describe the main issues in applying descriptor selection for QSAR methods and propose a novel two‐phase methodology for this task. The first phase makes use of a multi‐objective evolutionary technique which yields interesting advantages compared to mono‐objective methods. The second phase complements the first one and it enables to refine and improve the confidence in the chosen subsets of descriptors. This methodology allows the selection of subsets when a large number of descriptors are involved and it is also suitable for linear and nonlinear QSAR/QSPR models. The proposed method was tested using three data sets with experimental values for blood‐brain barrier penetration, human intestinal absorption and hydrophobicity. Results reveal the capability of the method for achieving subsets of descriptors with a high predictive capacity and a low cardinality. Therefore, our proposal constitutes a new promising technique helpful for the development of QSAR/QSPR models.
Is Feature Selection Essential for ANN Modeling?
Authors: Goodarzi Mohammad , Deshpande Shreekant , Murugesan Vanangamudi , Katti Seturam B. , Prabhakar Yenamandra S. 
Published: December 2009

AbstractIn modeling approaches, artificial neural networks (ANNs) have a special place to address the nonlinear phenomena or curved manifold. Often one or other feature selection approach is used prior to ANN to feed the input variables for its models. The function of ‘selected’ versus ‘arbitrary’ features on the outcome of ANN models is investigated with a variety of objectively selected and arbitrarily chosen variables from chemical databases namely thiazolidinones, anilinoquinolines and piperazinoquinolines. For each database, its biological activity is considered as the dependent variable and the molecular descriptors from DRAGON software are used as explanatory variables. The selection sets are obtained from feature selection approaches namely, combinatorial protocol in multiple linear regression, stepwise regression and genetic algorithm. Apart from these, a large number of arbitrary sets have been created by randomly picking the descriptors from corresponding databases. The features of all sets have shown a variety of inter‐ and intra‐ set diversities. A three‐layer back propagation ANN with Levenberg‐Marquardt optimization algorithm has been used for modeling the phenomena. Regardless of the origin of the feature sets, the ANN models from a very large number of sets have well explained the activity and qualified themselves to be predictive models. Also, no specific pattern is apparent between the quality of ANN model and the origin of its input feature set. Since these results are unusual, the study is extended to a few more databases. All the results emphasized the innate ability of ANN in developing complex network of relations among features to estimate the target variable. This has prompted us to suggest that prior feature selection is not essential for ANN and it is a desirable option for meaningful outputs in terms of the rationale behind the inputs.
Applications of Bond‐Based 3D‐Chiral Quadratic Indices in QSAR Studies Related to Central Chirality Codification
Authors: Castillo‐Garit Juan A. , Marrero‐Ponce Yovani , Torrens Francisco , García‐Domenech Ramon , Rodríguez‐Borges J. Enrique 
Published: December 2009

AbstractThe concept of bond‐based quadratic indices is generalized to codify chemical structure information for chiral drugs, making use of a trigonometric 3D‐chirality correction factor. In order to evaluate the effectiveness of this novel approach in drug design, we have modeled several well‐known data sets. In particularly, Cramer's steroid data set has become a benchmark for the assessment of novel QSAR methods. This data set has been used by several researchers using 3D‐QSAR approaches. Therefore, it is selected by us for the shake of comparability. In addition, to evaluate the effectiveness of this novel approach in drug design, we model the angiotensin‐converting enzyme inhibitory activity of perindoprilate's σ‐stereoisomers combinatorial library, as well as codify information related to a pharmacological property, highly dependent on the molecular symmetry, of a set of seven pairs of chiralN‐alkylated 3‐(3‐hydroxyphenyl)‐piperidines, which bind σ‐receptors. The validation of this method is achieved by comparison with earlier publications applied to the same data sets. The nonstochastic and stochastic bond‐based 3D‐chiral quadratic indices appear to provide a rather interesting alternative to other more common 3D‐QSAR descriptors.
A Bibliometric Study of Quantitative Structure‐Activity Relationships and QSAR & Combinatorial Science
Authors: Willett Peter 
Published: December 2009

AbstractThis paper reviews the articles published in Volumes 4–27 of the journals Quantitative Structure‐Activity Relationships and of QSAR & Combinatorial Science, focusing on the articles published in the journals, citations to those articles, the most productive authors and countries, and the relationship of the journals to the more general chemical literature.
Leveraging internal and external experience: exploration, exploitation, and R&D project performance
Authors: Hoang Ha , Rothaermel Frank T. 
Published: December 2009

AbstractAlthough one tenet in the alliance literature is that firms learn from prior experience, we posit that any potential learning effects depend on the type of experience. In particular, we hypothesize that alliance exploitation experience has positive effects on R&D project performance, while alliance exploration experience has negative effects. We further posit that an internal exploration competence allows firms to leverage their external exploitation experience more fully. In contrast, when firms combine internal exploitation experience with external exploration experience, the negative effects on R&D project performance become more pronounced. To test this integrative model of organizational learning, we leverage a unique and detailed dataset of 412 R&D projects in biotechnology conducted by large pharmaceutical companies between 1980 and 2000. Using a competing risk event history model predicting successful product approval versus project termination, we find support for our theoretical model. Copyright © 2010 John Wiley & Sons, Ltd.
When the glass is half full and half empty: CEOs' ambivalent interpretations of strategic issues
Authors: Plambeck Nils , Weber Klaus 
Published: December 2009

AbstractOrganizational scholars have highlighted the importance of interpretive ambivalence for mindfulness, creativity, and strategic change. Ambivalence occurs when an issue is seen simultaneously as positive and negative. We examine organizational factors that influence the propensity of organizational leaders to evaluate a new strategic issue ambivalently. Data come from a survey of 220 German CEOs confronted with the enlargement of the European Union. We find that CEOs of firms with a more ambidextrous strategic orientation and a moderate sense of organizational control over their environment are most likely to be ambivalent about this issue. Our findings affirm the prevalence of interpretive ambivalence at the executive level and suggest ways for organizations to promote or prevent ambivalence in strategic sensemaking. Copyright © 2010 John Wiley & Sons, Ltd.
NF κB Activation in Embryonic Endothelial Progenitor Cells Enhances Neovascularization via PSGL-1 Mediated Recruitment: Novel Role for LL37
Authors: Pfosser Achim , El-Aouni Chiraz , Pfisterer Iris , Dietz Melanie , Globisch Franziska , Stachel Georg , Trenkwalder Teresa , Pinkenburg Olaf , Horstkotte Jan , Hinkel Rabea , Sperandio Markus , Hatzopoulos Antonis K. , Boekstegers Peter , Bals Robert , Kupatt Christian 
Published: December 2009

Abstract
Embryonal endothelial progenitor cells (eEPCs) are capable of inducing therapeutic angiogenesis in a chronic hind limb model. However, the proportion of eEPCs recruited to the ischemic tissue appears to be a limiting step for the induction of cell-based therapeutic neovascularization. In the present study, we primed eEPCs with the human cathelicidin LL37 (hCAP-18) ex vivo to selectively enhance the eEPC-dependent gain of perfusion in vivo and elucidated the mechanism of action of LL37 on eEPCs. Seven days after femoral artery excision, 5 × 106 eEPCs (wt, wild type; p65t, transiently p65 transient; p65s, stable p65-transfected; LL37-eEPCs, LL37 peptide preincubated) were retroinfused into the anterior tibial vein. Recruitment of diI-labeled eEPCs in the ischemic gastrocnemic muscle was investigated 2 days later, whereas collateral growth and perfusion score (obtained by fluorescent microspheres) were assessed at day 7 and day 35 and are given as percentage of day 7 level. Capillary/muscle fiber ratio in the ischemic lower limb was obtained at day 35. Embryonic EPC recruitment in vitro and in vivo was found elevated after LL37 and p65t pretreatment, but not in p65s-eEPCs displaying increased IκBα or after LL37 in IκB-DN overexpressing eEPCs. Using LL37- and p65t-eEPCs, collateral growth (181 ± 10% and 165 ± 8%, respectively) surpassed that of wt-eEPCs (135 ± 7%), increasing perfusion ratio (208 ± 20% and 210 ± 17% vs. 142 ± 12% in wt-eEPCs, respectively), whereas p65s-eEPCs exerted no additive effect (collateral growth 130 ± 8%; perfusion ratio 155 ± 15%). Moreover, p65t-eEPC-induced neovascularization was abrogated by blocking antibodies against E-selectin and P-selectin glycoprotein ligand-1 (PSGL-1). We conclude that NF κB activation by LL37 or transient p65-transfection increases functionally relevant eEPC recruitment to ischemic muscle tissue via induction of PSGL-1 and E-selectin.
International amphibian micronucleus standardized procedure (ISO 21427‐1) for in vivo evaluation of double‐walled carbon nanotubes toxicity and genotoxicity in water
Authors: Mouchet Florence , Landois Perine , Datsyuk Vitaliy , Puech Pascal , Pinelli Eric , Flahaut Emmanuel , Gauthier Laury 
Published: December 2009

AbstractConsidering the important production of carbon nanotubes (CNTs), it is likely that some of them will contaminate the environment during each step of their life cycle. Nevertheless, there is little known about their potential ecotoxicity. Consequently, the impact of CNTs on the environment must be taken into consideration. This work evaluates the potential impact of well characterized double‐walled carbon nanotubes (DWNTs) in the amphibian larvae Xenopus laevis under normalized laboratory conditions according to the International Standard micronucleus assay ISO 21427‐1:2006 for 12 days of half‐static exposure to 0.1–1–10 and 50 mg L−1 of DWNTs in water. Two different endpoints were carried out: (i) toxicity (mortality and growth of larvae) and (ii) genotoxicity (induction of micronucleated erythrocytes). Moreover, intestine of larvae were analyzed using Raman spectroscopy. The DWNTs synthetized by catalytic chemical vapor deposition (CCVD) were used as produce (experiment I) and the addition of Gum Arabic (GA) was investigated to improve the stability of the aqueous suspensions (experiment II). The results show growth inhibition in larvae exposed to 10 and 50 mg L−1 of DWNTs with or without GA. No genotoxicity was evidenced in erythrocytes of larvae exposed to DWNTs, except to 1 mg L−1 of DWNTs with GA suggesting its potential effect in association with DWNTs at the first nonacutely toxic concentration. The Raman analysis confirmed the presence of DWNTs into the lumen of intestine but not in intestinal tissues and cells, nor in the circulating blood of exposed larvae. © 2009 Wiley Periodicals, Inc. Environ Toxicol, 2010.
A critical assessment of computer tools for calculating composite wind turbine blade properties
Authors: Chen Hui , Yu Wenbin , Capellaro Mark 
Published: December 2009

AbstractThe purpose of this paper is to critically assess several computer tools for calculating the inertial and structural properties of wind turbine blades. The theoretical foundation of each tool is briefly summarized, and the advantages and disadvantages of each tool are pointed out. Several benchmark examples, including a circular aluminium tube, a highly heterogeneous section, a multi‐layer composite pipe, an isotropic blade‐like section and a realistic composite wind turbine blade are used to evaluate the performance of different tools. Such a systematic and critical assessment provides guidance for wind turbine blade engineers to choose the right tool for effective design and analysis of wind turbine blades. Copyright © 2009 John Wiley & Sons, Ltd.
Physicochemical Properties of Garden Cress (Lepidium sativum L.) Seed Oil
Authors: Diwakar Bastihalli Tukaram , Dutta Pinto Kumar , Lokesh Belur Ramaswamy , Naidu Kamatham Akhilender 
Published: December 2009

AbstractGarden cress (Lepidium sativum L.) is an edible, underutilised herb, grown mainly for its seeds in India. Physicochemical properties, minor components (unsaponifiable matter, tocopherols, carotenoids), fatty acid composition and storage stability of garden cress seed oil (GCO) were studied. Cold press, solvent and supercritical CO2 extraction methods were employed to extract the oil. The total oil content of garden cress (GC) seeds was 21.54, 18.15 and 12.60% respectively by solvent, supercritical CO2 and cold press methods. The physical properties of GCO extracted by the above methods were similar in terms of refractive index, specific gravity and viscosity. However, cold pressed oil showed low PV and FFA compared to the oil extracted by other methods. α‐Linolenic acid (34%) was the major fatty acid in GCO followed by oleic (22%), linoleic (11.8%), eicosanoic (12%), palmitic (10.1%) erucic (4.4%), arachidic (3.4%) and stearic acids (2.9%). Oleic acid (39.9%) and α‐linolenic acid (42.1%) were the predominant fatty acids at the sn‐2 position. The total tocopherol and carotenoid content of GCO was 327.42 and 1.0 μmol/100 g oil, respectively. The oil was stable up to 4 months at 4 °C. Tocopherol and BHT offered the least protection, while ascorbyl palmitate (200 ppm) offered the maximum protection to the oil, when subjected to the accelerated oxidative stability test. Thus GCO can be considered as a fairly stable oil with a high content of α‐linolenic acid.