bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Monoammoniate of Lithium Borohydride, Li(NH3)BH4: An Effective Ammonia Storage Compound
Authors: Johnson Simon R. , David William I. F. , Royse David M. , Sommariva Marco , Tang Christina Y. , Fabbiani Francesca P. A. , Jones Martin O. , Edwards Peter P. 
Published: April 2009

AbstractStore it up: The ammoniate, Li(NH3)BH4, has been prepared and fully characterized by Raman and NMR spectroscopy and X‐ray powder diffraction. The potential for its use as an ammonia store and a comparison to other ammonia storage materials is discussed.magnified imageLithium borohydride absorbs anhydrous ammonia to form four stable ammoniates; Li(NH3)nBH4, mono‐, di‐, tri‐, and tertraammoniate. This paper focuses on the monoammoniate, Li(NH3)BH4, which is readily formed on exposure of LiBH4 to ammonia at room temperature and pressure. Ammonia loss from Li(NH3)BH4 commences around 40 °C and the compound transforms directly to LiBH4. The crystal structure of Li(NH3)BH4 is reported here for the first time. Its close structural relationship with LiBH4 provides a clear insight into the facile nature and mechanism of ammonia uptake and loss. These materials not only represent an excellent high weight‐percent ammonia system but are also potentially important hydrogen stores.
It's a long way from amphioxus: descendants of the earliest chordate
Authors: Garcia‐Fernàndez Jordi , Benito‐Gutiérrez Èlia 
Published: April 2009

AbstractThe origin of chordates and the consequent genesis of vertebrates were major events in natural history. The amphioxus (lancelet) is now recognised as the closest extant relative to the stem chordate and is the only living invertebrate that retains a vertebrate‐like development and body plan through its lifespan, despite more than 500 million years of independent evolution from the stem vertebrate. The inspiring data coming from its recently sequenced genome confirms that amphioxus has a prototypical chordate genome with respect to gene content and structure, and even chromosomal organisation. Pushed by joint efforts of amphioxus researchers, amphioxus is now entering a new era, namely its maturation as a laboratory model, through the availability of a large amount of molecular data and the advent of experimental manipulation of the embryo. These two facts may well serve to illuminate the hidden secrets of the genetic changes that generated, among other vertebrates, ourselves.
Epidemiology of a tick‐borne viral infection: theoretical insights and practical implications for public health
Authors: Moshkin Mikhail P. , Novikov Eugene A. , Tkachev Sergey E. , Vlasov Valentin V. 
Published: April 2009

AbstractThe morbidity of tick‐borne encephalitis (TBE) varies yearly by as much as 10‐fold among the people of Western Siberia. This long‐term variation is dependent on many factors such as the density of the tick populations, the prevalence of TBE virus (TBEV) among sub‐adult ticks, the yearly virulence of the TBEV, and prophylactic measures. Here we highlight the role of small mammal hosts in the circulation of TBEV through the ecosystem. Refining classical models of non‐viremic horizontal transmission, we emphasize the recently understood fact that the physiological and immunological status of the small mammal hosts affects the tick and virus‐host interactions. In addition to its theoretical interest, our approach may lead to some practical improvements in the precision of epidemiological forecasts and perhaps in forestalling the severity of outbreaks of TBE, or, at least, in forewarning medical authorities and the general public of impending TBE outbreaks.
Thermodynamic and Computational Studies on the Binding of p53‐Derived Peptides and Peptidomimetic Inhibitors to HDM2
Authors: Grässlin Anja , Amoreira Celine , Baldridge Kim K. , Robinson John A. 
Published: April 2009

AbstractHelix power: The binding interactions of linear and constrained β‐hairpin‐shaped peptides with HDM2 were compared by using experimental and theoretical methods. The entropic advantages enjoyed by the constrained peptides were found to be largely offset by reduced enthalpic contributions to binding of the cyclic mimetics. Formation of hydrogen bonds upon helix folding could contribute significantly to the enhanced enthalpy observed in binding of the linear peptides.magnified imageThe human double minute 2 protein (HDM2) binds a short peptide derived from the N terminus of the tumor‐suppressor protein, p53. This peptide (p53 residues 15–29) is flexible in free solution, but upon binding to HDM2 it folds into an amphipathic α‐helical conformation. Three residues along one face of the p53 helix (Phe19, Trp23, and Leu26) dock into hydrophobic pockets on the surface of HDM2. A conformationally constrained cyclic β‐hairpin peptidomimetic of p53, with residues Phe1, 6‐chloro‐Trp3, and Leu4 in one strand of the β‐hairpin, was shown earlier to dock into the same pockets on HDM2. Here, we show by isothermal titration calorimetry that the entropy loss upon binding of the constrained peptide to HDM2 is, as would be expected, much lower (TΔS≈10 kcal mol−1 at 300 K) than that for the linear peptide. However, the entropic advantage enjoyed by the constrained peptide is largely offset by a reduced enthalpic contribution, relative to the linear peptide, to binding of the cyclic mimetic. To explore the electronic nature of the interactions between the energetically important residues in each ligand and HDM2, hybrid quantum mechanical and electrostatic Poisson–Boltzmann computational studies were performed. The calculations reveal that significant stabilizing van der Waals interactions and polarization effects occur between the Trp side chain in each ligand and aromatic and aliphatic residues in HDM2. These stabilizing interactions are enhanced when a 6‐chloro substituent is incorporated into the Trp, in agreement with the experimental studies. In addition, the calculations suggest that at least one stabilizing hydrogen bond is formed, between the Trp indole‐NH in both ligands and HDM2. Other hydrogen‐bonding interactions also arise, however, along the α‐helical backbone of the linear peptide upon binding to HDM2, but are not mimicked in the constrained inhibitor–HDM2 complex. The formation of these hydrogen bonds upon helix folding could contribute significantly to the enhanced enthalpy observed in binding of the linear peptide to HDM2.
Warped factor analysis
Authors: Hong Sungjin 
Published: April 2009

AbstractShifted factor analysis (SFA) is designed to fit overall position shifts of sequential factors as well as the variation of factor weights. SFA is one kind of nonlinear generalization of linear factor models such as the two‐mode principal component model and the three‐mode Parafac model. Warped factor analysis (WFA), presented here, further generalizes SFA so that it fits factor variation due to not only the position shifts and the systematic weighting but also more flexible shape changes of sequential factors. A quasi alternating least squares (ALS) procedure is developed for WFA, using a simplified warping of segmented sequential factors. The most unique property of WFA is that it allows sequential factors to change shape distinctively, which is unlike what is implicitly assumed in mapping of data profiles, namely that sequential factors change shape together. Unlike the two‐mode factor/component models, two‐mode SFA was empirically shown to yield an essentially unique solution, using the additional sources of information provided by fitting systematic position shifts. Likewise, factors recovered by two‐mode WFA are likely to be essentially unique due to the systematic shape variance fit by the model, provided that the data contain sufficient sources of shape variation. Copyright © 2009 John Wiley & Sons, Ltd.
Robustified least squares support vector classification
Authors: Debruyne Michiel , Serneels Sven , Verdonck Tim 
Published: April 2009

AbstractSupport vector machine (SVM) algorithms are a popular class of techniques to perform classification. However, outliers in the data can result in bad global misclassification percentages. In this paper, we propose a method to identify such outliers in the SVM framework. A specific robust classification algorithm is proposed adjusting the least squares SVM (LS‐SVM). This yields better classification performance for heavily tailed data and data containing outliers. Copyright © 2009 John Wiley & Sons, Ltd.
Rearrangement of β‐amino alcohols and application to the synthesis of biologically active compounds
Authors: Cossy Janine , Pardo Domingo Gomez , Dumas Cécile , Mirguet Olivier , Déchamps Ingrid , Métro Thomas‐Xavier , Burger Benjamin , Roudeau Rémi , Appenzeller Jérôme , Cochi Anne 
Published: April 2009

Abstractβ‐Amino alcohols derived from natural amino acids have been used extensively as a powerful source of chirality. Transformation of the hydroxy group of these β‐amino alcohols into a good leaving group, by using trifluoroacetic anhydride, led to rearranged β‐amino alcohols in good yields and with high enantiomeric excesses. This rearrangement has allowed the transformation of substituted prolinols to substituted 3‐hydroxypiperidines and linear β‐amino alcohols, issued from natural amino acids, to rearranged β‐amino alcohols. Chirality, 2009. © 2009 Wiley‐Liss, Inc.
Chiral amino amides for the ruthenium(II)‐catalyzed asymmetric transfer hydrogenation reaction of ketones in water
Authors: Mao Jincheng , Guo Jun 
Published: April 2009

AbstractThe chiral amino amide 3 was derived from L‐proline and used for the [RuCl2(p‐cymene)]2‐catalyzed asymmetric transfer hydrogenation of prochiral ketones performed in water. Moderate to good chemical selectivities (up to 95% yield) and enantioselectivities (up to 90% ee) were obtained in the presence of 2 mol % of TBAB (n‐Bu4NBr) as the phase transfer catalyst. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Parallel kinetic resolution of D‐labelled 2‐aryl‐propionic and butanoic acids using quasi‐enantiomeric combinations of oxazolidin‐2‐ones
Authors: Coulbeck Elliot , Dingjan Marco , Eames Jason 
Published: April 2009

AbstractThe parallel kinetic resolution of racemic 2‐aryl‐2‐deuterio‐propionic and butanoic acids using an equimolar combination of quasi‐enantiomeric oxazolidin‐2‐ones is discussed. The levels of diastereoselectivity were high leading to enantiomerically pure D‐labeled products in good yield. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
The asymmetric synthesis of (R,R)‐formoterol via transfer hydrogenation with polyethylene glycol bound Rh catalyst in PEG2000 and water
Authors: Huang Ling , Liu Juntao , Shan Wenjun , Liu Bao , Shi Anding , Li Xingshu 
Published: April 2009

Abstract(R,R)‐formoterol was synthesized in seven steps with 4‐hydroxyl‐3‐nitro‐acetophenone as the starting material. The key intermediate, the chiral secondary alcohol 4, was prepared via Rh‐catalyzed asymmetric transfer hydrogenation with (S,S)‐PEGBsDPEN as the ligand and sodium formate as the hydrogen donor under mild conditions. With a mixture of PEG 2000 and water as the reaction media, the catalyst system could be recycled four times. Chirality, 2010. © 2009 Wiley‐Liss, Inc.
Lung cancer susceptibility and prognosis associated with polymorphisms in the nonhomologous end‐joining pathway genes
Authors: Tseng Ruo‐Chia , Hsieh Feng‐Jen , Shih Chuen‐Ming , Hsu Han‐Shui , Chen Chih‐Yi , Wang Yi‐Ching 
Published: April 2009

AbstractBACKGROUND:Nonsmall cell lung cancer (NSCLC) frequently exhibits genomic instability, such as high fractional allelic loss (FAL). Genomic instability may result from unrepaired or misrepaired double‐strand breaks (DSBs). The authors of this report postulated that polymorphisms in genes of the nonhomologous end‐joining (NHEJ) pathway, which is the major DSB repair pathway in mammalian cells, may modulate lung cancer susceptibility and prognosis.METHODS:Patients with NSCLC (n = 152) and a group of appropriate age‐matched and sex‐matched controls (n = 162) were subjected to genotype analysis of the NHEJ pathway genes x‐ray repair complementing defective repair in Chinese hamster cells 6 (Ku70) (reference single nucleotide polymorphism number [rs] 2267437), x‐ray repair complementing defective repair in Chinese hamster cells 5 (Ku80) (rs3835), x‐ray repair complementing defective repair in Chinese hamster cells 4 (XRCC4) (rs1805377), and DNA ligase IV (LIG4) (rs1805388). The gene‐gene interaction (joint effect), genotype‐environmental (ie, smoking) correlation, and genotype‐phenotype (ie, FAL) correlation were examined. The Kaplan‐Meier method and log‐rank tests were used to assess the prognostic effect.RESULTS:There was a significant association between the XRCC4 and LIG4 genotypes with NSCLC risk in an analysis of individual polymorphism associations, and the risk of NSCLC increased further in a combined analysis of multiple polymorphisms (adjusted odds ratio [OR], 8.74). The patients who had a homozygous variant guanine/guanine genotype of the XRCC4 gene had a poorer prognosis compared with other patients (P = .015). There was a significant difference between the patient smokers and controls for XRCC4 (adjusted OR, 2.67) and LIG4 (adjusted OR, 2.04). In addition, polymorphisms in XRCC4 and LIG4 were linked significantly with patients who had high FAL (adjusted OR, 2.03‐3.84).CONCLUSIONS:To the authors' knowledge, this is the first nested case‐control study to demonstrate a significant association between the polymorphisms of genes in the NHEJ pathway and lung cancer susceptibility and prognosis. The results may be useful for risk assessment and disease monitoring of patients with NSCLC. Cancer 2009. © 2009 American Cancer Society.
Anomalous Odd–Even Effects in Columnar and Smectic Phases of Discotic Tetraphenylenes
Authors: Hägele Constanze , Wuckert Eugen , Laschat Sabine , Giesselmann Frank 
Published: April 2009

AbstractRather uncommon but pronounced odd–even effects in the clearing temperatures of liquid crystals are found for three new homologous series of discotic tetraphenylenes (see figure). Detailed similarities to the well‐known odd‐even effects in calmitic mesogens point towards a more general understanding of odd‐even effects in liquid crystals.magnified imageThe phase transition temperatures in many homologous series of liquid crystals show odd‐even effects similar to the well‐known odd‐even effects in non‐mesogenic organic compounds like carboxylic acids. For discotic liquid crystals only a few series with a sufficient number of consecutive homologues are available and only a small part of these series show odd‐even effects at all. We now synthesized and investigated three series of discotic tetraphenylenes each ranging from the n=7 to the n=16 homologues. For these compounds an anomalous odd–even effect is found: The ascending and descending transition temperatures with increasing number of methylene groups in the side chains exhibit an inversion of this alternation which is always found between the n=12 and n=14 homologues. An overview of odd–even effects in liquid crystals is presented and we discuss the nature and the origin of odd–even effect in discotic mesogens.
Towards the Efficient, Total Glycan Utilization of Biomass
Authors: Mascal Mark , Nikitin Edward B. 
Published: April 2009

AbstractFrom biomass to mass transportation: Waste biomass (newspaper, corn stover, straw, and wood) is converted into biofuel precursors and value‐added products in excellent yield using a simple, inexpensive process involving concurrent hydrolysis, dehydration, and substitution reactions in a biphasic reactor. The hemicellulose fraction of these substrates is simultaneously converted into furfural, and together these constitute an efficient means for the total exploitation of the carbohydrate content of biomass.magnified image
Interplay of actors, scales, frameworks and regimes in the governance of biodiversity
Authors: Paavola Jouni , Gouldson Andrew , Kluvánková‐Oravská Tatiana 
Published: April 2009

AbstractThis article examines the key contributions of the political science and systems theory based literatures on environmental governance, and uses them to analyse the governance of biodiversity in Europe. The article suggests that the key insights of the two bodies of literature are a distinction between governance frameworks and regimes on one hand, and the importance of multifaceted and multiple scales on the other. These key insights draw attention to horizontal and vertical forms of interplay. The article suggests that interplay, both between actors and levels and between frameworks and regimes, is ubiquitous and ambivalent: it can either foster or hinder environmental governance. The article illustrates this discussion in the context of governance of biodiversity in Europe, highlighting how vertical and horizontal interplay between the governance framework for biodiversity and the broader institutional setting or regime have characterized the implementation of the Habitats Directive, both complicating and fostering the governance of biodiversity in Europe. Copyright © 2009 John Wiley & Sons, Ltd and ERP Environment.
Human natural Treg microRNA signature: Role of microRNA‐31 and microRNA‐21 in FOXP3 expression
Authors: Rouas Redouane , Fayyad‐Kazan Hussein , El Zein Nabil , Lewalle Philippe , Rothé Françoise , Simion Alexandru , Akl Haidar , Mourtada Mohamad , El Rifai Mohamad , Burny Arsène , Romero Pedro , Martiat Philippe , Badran Bassam 
Published: April 2009

AbstractTreg are the main mediators of dominant tolerance. Their mechanisms of action and applications are subjects of considerable debate currently. However, a human microRNA (miR) Treg signature has not been described yet. We investigated human natural Treg and identified a signature composed of five miR (21, 31, 125a, 181c and 374). Among those, two were considerably under‐expressed (miR‐31 and miR‐125a). We identified a functional target sequence for miR‐31 in the 3′ untranslated region (3′ UTR) of FOXP3 mRNA. Using lentiviral transduction of fresh cord blood T cells, we demonstrated that miR‐31 and miR‐21 had an effect on FOXP3 expression levels. We showed that miR‐31 negatively regulates FOXP3 expression by binding directly to its potential target site in the 3′ UTR of FOXP3 mRNA. We next demonstrated that miR‐21 acted as a positive, though indirect, regulator of FOXP3 expression. Transduction of the remaining three miR had no direct effect on FOXP3 expression or on the phenotype and will remain the subject of future investigations. In conclusion, not only have we identified and validated a miR signature for human natural Treg, but also unveiled some of the mechanisms by which this signature was related to the control of FOXP3 expression in these cells.
Hydrotalcite‐Like Nanocrystals from Water‐in‐Oil Microemulsions
Authors: Bellezza Francesca , Cipiciani Antonio , Costantino Umberto , Nocchetti Morena , Posati Tamara 
Published: April 2009

AbstractA water‐in‐oil microemulsion made up of a cetyltrimethylammonium bromide/n‐butanol/isooctane/MII and AlIII nitrate aqueous solution (MII = Mg or Ni or Zn) has been mixed with a microemulsion of the same composition but containing an ammonia solution instead of a metal nitrate solution. Collisions between the reverse micelles containing an MII and AlIII solution and those containing an NH3 solution form short‐lived dimers that act as reaction vessels and control the nucleation and growth of MgAl, NiAl or ZnAl hydrotalcite‐like compounds (HTlcs). The double water‐in‐oil microemulsion technique yields colloidal dispersions of nanoparticles whose size and shape were examined by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The colloidal particles were between 50 and 100 nm depending on the composition of the microemulsions (water‐to‐surfactant and oil‐to‐water molar ratios). The separation of the nanoparticles from the reaction medium produces a gel made up of surfactant‐free particles. HTlc nanocrystals were recovered from the gel (reaction medium), washed, and dried. They were then studied by chemical and thermogravimetric analyses, X‐ray powder diffraction, N2‐adsorption and BET surface analysis and scanning electron microscopy (SEM). The AlIII/(MII + AlIII) molar ratio of the recovered HTlc nanocrystals was between 0.24 and 0.29, and the basal spacing was about 8 Å, a value in agreement with the presence of charge compensating bromide anions in the interlayer region. The proposed technique allows for HTlc nanocrystals to be obtained with a relatively high surface area with values ranging between 50 and 110 m2/g. The SEM analyses show that the nanoparticles are aggregated to give rise to complex spherical or rod‐shaped microstructures.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
The Contribution of Electrospray Mass Spectrometry to the Study of Metal Complexes: The Case of Copper(II)–Dipeptide Systems
Authors: Maccarrone Giuseppe , Caruso Rosario , Contino Annalinda , Giuffrida Alessandro , Messina Marianna , Cucinotta Vincenzo 
Published: April 2009

AbstractFollowing a previous thermodynamic and spectroscopic investigation, 13 copper(II)–dipeptide complexes have been characterized by electrospray ionization mass spectrometry (ESI‐MS) and visible optical spectroscopy. The data obtained confirm the presence of the species singled out by the thermodynamic approach, showing the ability of electrospray mass spectrometry to give evidence of the presence of a water molecule in the copper(II) in‐plane coordination. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis, Structure and Catalysis of Tetranuclear Copper(II) Open Cubane for Henry Reaction on Water
Authors: Jammi Suribabu , Punniyamurthy Tharmalingam 
Published: April 2009

AbstractThe copper(II) open cubane 1 has been synthesized and its structure determined. It is insoluble in water and efficiently catalyzes the Henry reaction with high yield. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Ratiometric Fluorescence Sensing of Fluoride Ions by an Asymmetric Bidentate Receptor Containing a Boronic Acid and Imidazolium Group
Authors: Xu Zhaochao , Kim Sook Kyung , Han Su Jung , Lee Chongmok , Kociok‐Kohn Gabriele , James Tony D. , Yoon Juyoung 
Published: April 2009

AbstractThe synthesis of the first examples of anion receptors that utilize boron–fluoride interactions and (C–H)+···F–‐type ionic hydrogen‐bond interactions in the binding of F ions is reported herein. o‐, m‐, and p‐Phenylboronic acids were linked to naphthoimidazolium through a methylene group. On the basis of fluorescence and 19F NMR studies, we have confirmed that the addition of fluoride to a boron center occurs prior to the formation of (C–H)+···F–‐type ionic hydrogen bond with the imidazolium moiety. More importantly, these investigations have demonstrated that only the receptor bearing the ortho‐directed boron and imidazolium exhibits enhanced fluoride binding. The increased binding ability of the asymmetric bidentate receptor of ortho‐boronic acid and imidazolium towards F– enables it to sense fluoride ions in a 95:5 CH3CN/HEPES aqueous solution. The fluorescence responses to different anions were also explored; the ortho‐boron‐imidazolium receptor displayed ratiometric fluorescence changes and a high selectivity towards fluoride ions over other anions (Cl–, Br–, CH3CO2–, HSO4–, and H2PO4–).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)