bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intramolecular Carbolithiation of 2,6‐Dilithio‐1,6‐heptadienes: An Experimental and Theoretical Study
Authors: Sanz Roberto , Ignacio José M. , Rodríguez Miguel A. , Fañanás Francisco J. , Barluenga José 
Published: March 2007

Abstract2,6‐Dilithio‐1,6‐heptadienes 3 undergo intramolecular carbolithiation in Et2O/N,N,N′,N′‐tetramethylethylenediamine (TMEDA) at the lithiated double bonds to afford 1,2‐bis(lithiomethyl)cyclopentenes 5. Reaction of these dianions with electrophiles affords a number of 1,2‐difunctionalized cyclopentene derivatives 7–10. The ease of carbolithiation of 2,6‐dilithio‐1,6‐heptadiene (3 a) compared to that of 2‐lithio‐1,6‐heptadiene (14) has been studied experimentally. A series of ab initio molecular‐orbital calculations on the course of the reaction were carried out and the results were compared to those for the corresponding intramolecular carbolithiation of an isolated double bond. The LiC interactions found in the transition state by this theoretical study support a carbolithiation pathway for the cyclization of 2,6‐dilithio‐1,6‐heptadienes.
Rapid and Simple Solid‐Phase Esterification of Sialic Acid Residues for Quantitative Glycomics by Mass Spectrometry
Authors: Miura Yoshiaki , Shinohara Yasuro , Furukawa Jun‐ichi , Nagahori Noriko , Nishimura Shin‐Ichiro 
Published: March 2007

AbstractA rapid and quantitative method for solid‐phase methyl esterification of carboxy groups of various sialylated oligosaccharides has been established. The method employed a triazene derivative, 3‐methyl‐1‐p‐tolyltriazene, for facile derivatization of oligosaccharides immobilized onto general solid supports such as Affi‐Gel Hz and gold colloidal nanoparticles in a multiwell plate. The workflow protocol was optimized for the solid‐phase processing of captured sialylated/unsialylated oligosaccharides separated from crude sample mixtures by chemical ligation. From tryptic and/or PNGase F‐digest mixtures of glycoproteins, purification by chemoselective immobilization, esterification and recovery were achieved in the same well of the filter plate within three hours when used in conjunction with “glycoblotting technology” (S.‐I. Nishimura, K. Niikura, M. Kurogochi, T. Matsushita, M. Fumoto, H. Hinou, R. Kamitani, H. Nakagawa, K. Deguchi, N. Miura, K. Monde, H. Kondo, High‐throughput protein glycomics: Combined use of chemoselective glycoblotting and MALDI‐TOF/TOF mass spectrometry: Angew. Chem. 2005, 117, 93–98; Angew. Chem. Int. Ed. 2005, 44, 91–96). The recovered materials were directly applicable to subsequent characterization by mass spectrometric techniques such as MALDI‐TOF for large‐scale glycomics of both neutral and sialylated oligosaccharides. On‐bead/on‐gold nanoparticle derivatization of glycans containing sialic acids allowed rapid and quantitative glycoform profiling by MALDI‐TOF MS with reflector and positive ion mode. In addition to its simplicity and speed, the method eliminates the use of unfavorable halogenated solvents such as chloroform and dichloromethane or volatile solvents such as diethyl ether and hexane, resulting in a practical and green chemical method for automated robotic adaptation.
Ovarian cancer screening with annual transvaginal sonography
Authors: van Nagell John R. , DePriest Paul D. , Ueland Frederick R. , DeSimone Christopher P. , Cooper Amy L. , McDonald J. Matt , Pavlik Edward J. , Kryscio Richard J. 
Published: March 2007

AbstractBACKGROUNDOvarian cancer has the highest mortality rate of all gynecologic malignancies, and most women present with advanced‐stage disease. The current investigation was performed to determine the efficacy of annual transvaginal sonography (TVS) as a screening method for ovarian cancer.METHODSAnnual TVS screening was performed on 25,327 women from 1987 to 2005. Asymptomatic women aged ≥50 years and women aged ≥25 years who had a family history of ovarian cancer were eligible for participation in this trial.RESULTSAmong 364 patients (1.4%) with a persisting ovarian tumor on TVS who underwent exploratory laparoscopy or laparotomy with tumor removal, 35 primary invasive ovarian cancers, 9 serous ovarian tumors of low malignant potential, and 7 cancers metastatic to the ovary were detected. Stage distribution was as follows: 28 patients had stage I disease, 8 patients had stage II disease, and 8 patients had stage III disease. Four patients died of disease, 2 patients died of other causes, and 38 patients were alive and well from 0.5 years to 15.8 years after diagnosis (mean, 5.3 years). Nine women developed ovarian cancer within 12 months of a negative screen (false‐negative results), and 3 of these patients died of disease. TVS screening had a sensitivity of 85.0%, specificity of 98.7%, positive predictive value of 14.01%, and negative predictive value of 99.9%. After 107,276 screening years, there have been 7 ovarian cancer deaths in the annually screened population and 3 ovarian cancer deaths among women who were noncompliant. Excluding patients with nonepithelial or borderline ovarian malignancies, the survival of patients with ovarian cancer in the annually screened population was 89.9% ± 10.1% at 2 years and 77.2% ± 22.8% at 5 years.CONCLUSIONSTVS screening, when it was performed annually, was associated with a decrease in disease stage at detection and with case‐specific ovarian cancer mortality, but it was not effective in detecting ovarian cancers in women who had normal ovarian volume. Cancer 2007; © 2007 American Cancer Society.
Btk and phospholipase Cγ2 can function independently during B cell development
Authors: Halcomb Kristina E. , Contreras Cristina M. , Hinman Rochelle M. , Coursey Terry G. , Wright Heather L. , Satterthwaite Anne B. 
Published: March 2007

AbstractThe pre‐BCR and the BCR regulate B cell development via a signalosome nucleated by the adaptor protein B cell linker protein (BLNK). Formation of this complex facilitates activation of phospholipase C (PLC) γ2 by Bruton's tyrosine kinase (Btk). To determine whether Btk and PLCγ2 also have separate functions, we generated Btk–/–PLCγ2–/– mice. They demonstrated a block in development at the pre‐B stage and increased pre‐BCR surface expression. This phenotype was more severe than that of Btk–/– or PLCγ2–/– mice. Although both Btk and PLCγ2 were required for proliferation of splenic B cells in response to BCR cross‐linking, they contributed differently to anti‐IgM‐induced phosphorylation of ERK. Btk–/– and PLCγ2–/– mice each had a reduced frequency of Igλ‐expressing B cells and impaired migration of pre‐B cells towards stromal cell‐derived factor 1. However, the increase in pre‐B cell malignancy that occurs in BLNK–/– mice in the absence of Btk was not observed in the absence of PLCγ2. Thus, Btk and PLCγ2 act both in concert and independently throughout B cell development.
Redox‐Induced μ‐Acetato and μ‐Oxo Core Interconversions in Dinuclear Manganese Tris(2‐methylpyridyl)amine (tpa) Complexes: Isolation and Characterization of [Mn2III(μ‐O)(μ‐O2CCH3)(tpa)2]3+
Authors: Collomb Marie‐Noëlle , Mantel Claire , Romain Sophie , Duboc Carole , Leprêtre Jean‐Claude , Pécaut Jacques , Deronzier Alain 
Published: March 2007

AbstractThe electrochemical properties of the bis(μ‐acetato) complex [Mn2II(O2CCH3)2(tpa)2]2+ (12+) [tpa = tris(2‐methylpyridyl)amine] in an organic medium (CH3CN) have been studied. Two successive controlled potential oxidations of a solution of 12+ at 0.7 and 1.1 V vs. Ag/Ag+ (10 mM) allow the selective and nearly quantitative formation of the mono‐(μ‐oxo) mono‐(μ‐acetato) complex [Mn2III(O)(O2CCH3)(tpa)2]3+ (23+) and the bis(μ‐oxo) complex [Mn2IV(O)2(tpa)2]4+ (34+), respectively. These results show that each substitution of an acetate group by an oxo group is caused by an overall two‐electron oxidation of the corresponding dimanganese complex. The associated electrochemical back transformations were also investigated. Complex 23+, which possesses a rare mono‐(μ‐oxo) mono‐(μ‐acetato) motif, has been isolated and characterized by X‐ray crystallography. This complex crystallizes in the monoclinic system, space group P21/n with a = 11.9899(17), b = 35.050(5), c = 12.3952(18) Å, β = 101.218(6)°, Z = 4. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Unusual T4(1) Water Chain Stabilized in the One‐Dimensional Chains of a Copper(II) Coordination Polymer
Authors: Jin Yi , Che Yunxia , Batten Stuart R. , Chen Pangkuan , Zheng Jimin 
Published: March 2007

AbstractA novel T4(1) water chain in a new CuII coordination polymer, {[Cu(C4H6N2)2(C4H2O4)] (H2O)3}n (1, where C4H6N2 = 2‐methylimidazole, C4H2O4 = maleate), has been synthesized and structurally characterized by single‐crystal X‐ray diffraction. Thermogravimetry, infrared spectroscopy, elemental analysis, and magnetic analysis have also been used to characterize 1. Complex 1 crystallizes in the trigonal space group P3221, and the 1‐D chains composed of cyclic water tetramers play an important role in stabilizing the overall polymeric structure. Furthermore, this 1‐D water chain presents an unusual association mode of water molecules.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Hydrothermal Synthesis of Single Crystalline (K,Na)NbO3 Powders
Authors: Sun Ce , Xing Xianran , Chen Jun , Deng Jinxia , Li Lu , Yu Ranbo , Qiao Lijie , Liu Guirong 
Published: March 2007

Abstract(K1–xNax)NbO3 (x = 0.01, 0.24, 0.89, 0.91, 0.99) single crystalline powders with perovskite structure were synthesized by a hydrothermal method with Nb2O5 in a mixed solution of KOH and NaOH at 220 °C for 24 h. XRD investigations showed that the structure of the synthesized (K1–xNax)NbO3 ceramics changed from a KNbO3‐type orthorhombic phase (space group Bmm2) to a NaNbO3‐type monoclinic phase (space group Pm) with the increase of Na content. The present results confirmed that (K1–xNax)NbO3 exhibited a morphotropic phase boundary (MPB) at around 50 %K separating the orthorhombic phase and monoclinic phase. FE‐SEM images showed that the morphological structures of niobates were cubes and nanofingers. The TEM image and the selected area electron diffraction pattern of (K0.01Na0.99)NbO3 showed the as‐synthesized powder was single crystalline and indexed to be monoclinic. The phase evolution of the products in the hydrothermal route revealed that the hydrothermal synthesis of (K1–xNax)NbO3 underwent two steps, where an intermediate product (K8–8xNa8x)Nb6O19·n H2O was found in the early stage and then pure (K1–xNax)NbO3 was obtained after another 30 min of hydrothermal treatment.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Valorisation of palm by‐products as functional components
Authors: Tan Yew‐Ai , Sambanthamurthi Ravigadevi , Sundram Kalyana , Wahid Mohd Basri 
Published: March 2007

AbstractValorisation of palm by‐products increases business opportunities for stakeholders in the palm oil industry. The approach also paves the way for structuring an eco‐efficient industry that recognises the importance of sustainable development for continued growth and competitiveness. Research underway in the palm oil industry has revealed a range of bioactives that can be used as functional components for food products that enhance health. Crude palm oil with 500–700 mg/kg of carotenes is one of the richest plant sources of provitamin A. Tocopherols and tocotrienols are also present in the oil at significant levels of between 600 and 1000 mg/kg. Besides the oil, by‐products of palm oil milling and refining also contain bioactives. Tocopherols and tocotrienols are concentrated in the palm fatty acid distillate (PFAD), a by‐product of physical refining of palm oil. Sterols and squalene can also be recovered from PFAD. Palm pressed fibres contain extractable phytochemicals such as sterols, vitamin E, carotenoids, phospholipids, squalene and phenolics. Water‐soluble palm phenolics have been successfully extracted from aqueous by‐products generated from the mill. These palm extracts show superior antioxidant potential and are earmarked for applications in functional foods, nutraceuticals, pharmaceuticals and cosmeticeuticals.
Palm oil and palm kernel oil as raw materials for basic oleochemicals and biodiesel
Authors: Rupilius Wolfgang , Ahmad Salmiah 
Published: March 2007

AbstractThe palm oil‐ and palm kernel oil‐producing countries in South East Asia are becoming the dominant producers of fatty acids and fatty alcohols. The large and very efficient palm oil plantations are giving the local producers of basic oleochemicals a decisive competitive advantage. The production of fatty acid methyl esters for use as biodiesel is expanding all around the world. In tropical countries, the preferred raw material for biodiesel is palm oil, Europe uses mostly low‐erucic rapeseed oil and the USA soya oil. To a large extent, the growth of biodiesel depends on direct or indirect subsidies for the agriculture and on tax exemptions. The rapid growth of biodiesel has created an excess of glycerine, which cannot be absorbed by existing markets. The price for glycerine will probably remain low for the next years and therefore attract investments in new applications.
Synthesis and Spectral Properties of Amphiphilic Lipids with Linear Conjugated Polyene and Phenylpolyene Fluorescent Groups
Authors: Quesada Ernesto , Delgado Javier , Hornillos Valentín , Acuña A. Ulises , Amat‐Guerri Francisco 
Published: March 2007

AbstractLipophilic fluorescent groups with a chain‐like linear conformation emitting in the visible range and with high photostability are presently unavailable. These structures would be of great interest as labels for long‐chain fatty acids and phospholipids lacking intrinsic fluorescent groups. With this aim in mind, we report the synthesis and the spectroscopic characterization of a series of emitting amphiphilic lipids that may approach that ideal fluorescent tag. Each lipid was constructed by attaching a linear, all‐(E) conjugated pentaene, tetraenyne, ω‐phenyltetraene, or ω‐phenyltrienyne chromophore to a hydrophilic head‐group through a polymethylene chain spacer. The key steps of the synthesis were the Pd0‐mediated cross‐coupling reaction between bromopolyenes and terminal acetylenic compounds, yielding tetraenynes or ω‐phenyltrienynes, and the subsequent triple‐bond partial reduction, producing the corresponding pentaenes or ω‐phenyltetraenes in good overall yields. This method represents a further successful example of the so‐called “acetylenic approach” to the indirect high‐yield synthesis of polyene systems. In the case of ω‐phenyltrienynes, a higher proportion of the all‐(E) isomer was obtained using an alternative method based on the reaction of an ω‐phenyldienylphosphonate with an α‐acetylenic aldehyde. Some of the resulting compounds exhibit spectral and photochemical properties that warrant their use as emitting lipophilic tags. Thus, the ω‐phenyltetraene and ω‐phenyltrienyne members of the series show intense absorption bands in the 320–370 nm range with fluorescence emission centered at 475 nm and quantum yields up to 0.25. These parameters are appropriate for the applications noted above. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Comprehensive Kinetic and Mechanistic Considerations for the Gas‐Phase Behaviour of Pinane‐Type Compounds
Authors: Stolle Achim , Ondruschka Bernd , Bonrath Werner 
Published: March 2007

AbstractThe thermal behaviour of selected pinane‐type compounds, α‐pinene (1), β‐pinene (2), pinane (3) and nopinone (4), has been investigated. The conversion of the bicyclic starting materials to their acyclic and monocyclic isomers as well as the consecutive reactions of the acyclic main isomerisation products are discussed. The conversion of 1–4 in a reaction network is presented and the experimental evidence for the formation of pyrolysis products by a biradical pathway is discussed. In addition to these results a kinetic model describing the isomerisation of the bicyclic compounds to their acyclic and monocyclic isomers is presented. A good correlation between kinetic simulations and experimental data is revealed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Photo‐ and Proton‐Dual‐Responsive Fluorescence Switch Based on a Bisthienylethene‐Bridged Naphthalimide Dimer and Its Application in Security Data Storage
Authors: Jiang Guiyuan , Wang Sheng , Yuan Wenfang , Zhao Zhen , Duan Aijun , Xu Chunming , Jiang Lei , Song Yanlin , Zhu Daoben 
Published: March 2007

AbstractA photo‐ and proton‐dual‐responsive fluorescence switch based on a bisthienylethene‐naphthalimide dimer was described. Security data storage based on this dual‐responsive fluorescent molecular switch was proposed and demonstrated. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Intermolecular FeCl3‐Catalyzed Hydroamination of Styrenes
Authors: Michaux Julien , Terrasson Vincent , Marque Sylvain , Wehbe Johny , Prim Damien , Campagne Jean‐Marc 
Published: March 2007

AbstractHydroamination reactions of vinylarenes with nonnucleophilic nitrogen derivatives (p‐toluenesulfonamide, p‐nitroaniline, p‐nitrobenzamide, ...) catalyzed by FeCl3 are described. Interestingly, these reactions are catalyzed by an environmentally friendly and an inexpensive catalyst in the absence of any ligand or cocatalyst. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)
Review of the literature examining the correlation among DNA microarray technologies
Authors: Yauk Carole L. , Berndt M. Lynn 
Published: March 2007

AbstractDNA microarray technologies are used in a variety of biological disciplines. The diversity of platforms and analytical methods employed has raised concerns over the reliability, reproducibility and correlation of data produced across the different approaches. Initial investigations (years 2000–2003) found discrepancies in the gene expression measures produced by different microarray technologies. Increasing knowledge and control of the factors that result in poor correlation among the technologies has led to much higher levels of correlation among more recent publications (years 2004 to present). Here, we review the studies examining the correlation among microarray technologies. We find that with improvements in the technology (optimization and standardization of methods, including data analysis) and annotation, analysis across platforms yields highly correlated and reproducible results. We suggest several key factors that should be controlled in comparing across technologies, and are good microarray practice in general. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
Evaluation of river water genotoxicity using the piscine micronucleus test
Authors: Ergene Serap , Çavaş Tolga , Çelik Ayla , Köleli Nurcan , Aymak Cemil 
Published: March 2007

AbstractThe Berdan River, which empties into the Mediterranean Sea on the east coast of Turkey, receives discharges of industrial and municipal waste. In the present study, the in vivo piscine micronucleus (MN) test was used to evaluate the genotoxicity of water samples collected from different locations along the Berdan River. Nile tilapia (Oreochromis niloticus) were exposed in the laboratory for 2, 4, and 6 days, and micronuclei were evaluated in peripheral blood erythrocytes, gill cells, and caudal fin epithelial cells. A single dose of 5 mg/L cyclophosphamide was used as a positive control. In addition to micronuclei, nuclear abnormalities (NAs), such as binucleated cells and blebbed, notched, and lobed nuclei, were assessed in the erythrocytes, and chemical analyses were carried out to determine the amount of heavy metals in the water samples. MN and NA frequencies were significantly elevated (up to 2‐ to 3‐fold) in fish exposed to river water samples taken downstream of potential discharges, and the elevated responses in gill and fin cells were related to the concentration of heavy metals in the water. MN frequencies (expressed as micronucleated cells/1,000 cells), in both treated and untreated fish, were greatest in gill cells (range: 0.80–3.70), and generally lower in erythrocytes (range: 0.50–2.80), and fin cells (range: 0.45–1.70). The results of this study indicate that the Berdan River is contaminated with genotoxic pollutants and that the genotoxicity is related to the discharge of wastes into the river water. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
Semiparametric zero‐inflated Poisson models with application to animal abundance studies
Authors: Chiogna Monica , Gaetan Carlo 
Published: March 2007

AbstractThis paper describes a framework for flexibly modeling zero‐inflated data. Semiparametric regression based on penalized regression splines for zero‐inflated Poisson models is introduced. Moreover, an EM‐type algorithm is developed to perform maximum likelihood estimation. As an illustration, a study of animal abundance is tackled. In fact, abundance often shows excess of zeroes and is a complicated function of the explanatory variables. In particular, the relationships between avian abundance and environmental variables indicating land use are tackled. Copyright © 2007 John Wiley & Sons, Ltd.
Dynamics of towers surrounded by water
Authors: Liaw C‐Y. , Chopra Anil K. 
Published: March 2007

AbstractThe effects of interaction with surrounding water on the dynamic response behaviour of cantilever tower structures are studied. Expressions for response to harmonic ground motion in individual modes of vibration, including hydrodynamic interaction, are presented, the accuracy of responses obtained by ignoring surface waves and compressibility of water in the hydrodynamic solutions is evaluated, the effects of hydrodynamic interaction on the fundamental period of vibration are studied and the commonly used ‘added mass’ approach to account for effects of surrounding water is examined. The conclusions deduced from the results of this investigation include the following. Interaction with surrounding water increases the fundamental period of vibration of the tower and decreases the modal damping ratio. Compressibility of water has essentially no influence in the hydrodynamic effects on slender towers. The traditional definition of added mass is conceptually deficient, but is simple to employ; the errors in this simple added mass representation are negligible for the first mode of vibration of towers.
A numerical study of damping
Authors: Thomson William T. , Calkins Tom , Caravani Paolo 
Published: March 2007

AbstractDiagonal damping matrices were computed for three systems which have non‐proportional damping matrices. These diagonal damping matrices were computed on three bases, as follows: 1. After normalizing the equations of motion by the modal matrix, the diagonal terms are retained ignoring the non‐diagonal terms. 2. Diagonal damping matrix is established by the optimization algorithm which minimizes the mean square error of the frequency response. 3. Diagonal damping is determined from the normalized differential equation by matching the peaks of the coupled and uncoupled system.The frequency responses for the three cases of one of the three systems are presented together with a comparison of the energy dissipation.