bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reduced Molybenum‐Oxide‐Based Core–Shell Hybrids: “Blue” Electrons Are Delocalized on the Shell
Authors: Todea Ana Maria , Szakács Julia , Konar Sanjit , Bögge Hartmut , Crans Debbie C. , Glaser Thorsten , Rousselière Hélène , Thouvenot René , Gouzerh Pierre , Müller Achim 
Published: May 2011

AbstractThe present study refers to a variety of reduced metal‐oxide core–shell hybrids, which are unique with regard to their electronic structure, their geometry, and their formation. They contain spherical {Mo72Fe30} Keplerate‐type shells encapsulating Keggin‐type polyoxomolybdates based on very weak interactions. Studies on the encapsulation of molybdosilicate as well as on the earlier reported molybdophosphate, coupled with the use of several physical methods for the characterization led to unprecedented results (see title). Upon standing in air at room temperature, acidified aqueous solutions obtained by dissolving sodium molybdate, iron(II) chloride, acetic acid, and molybdosilicic acid led to the precipitation of monoclinic greenish crystals (1). A rhombohedral variant (2) has also been observed. Upon drying at room temperature, compound 3 with a layer structure was obtained from 1 in a solid‐state reaction based on cross‐linking of the shells. The compounds 1, 2, and 3 have been characterized by a combination of methods including single‐crystal X‐ray crystallography, magnetic studies, as well as IR, Mössbauer, (resonance) Raman, and electronic absorption spectroscopy. In connection with detailed studies of the guest‐free two‐electron‐reduced {Mo72Fe30}‐type Keplerate (4) and of the previously reported molybdophosphate‐based hybrids (including 31P NMR spectroscopy results), it is unambiguously proved that 1, 2, and 3 contain non‐reduced Keggin ion cores and reduced {Mo72Fe30}‐type shells. The results are discussed in terms of redox considerations (the shell as well as the core can be reduced) including those related to the reduction of “molybdates” by FeII being of interdisciplinary including catalytic interest (the MoVI/MoV and FeIII/FeII couples have very close redox potentials!), while also referring to the special formation of the hybrids based on chemical Darwinism.
Probing the Role of the Linker in Ferrocene–ATP Conjugates: Monitoring Protein Kinase Catalyzed Phosphorylations Electrochemically
Authors: Martić Sanela , Labib Mahmoud , Freeman Daniel , Kraatz Heinz‐Bernhard 
Published: May 2011

AbstractThe synthesis and electrochemical properties of ferrocene conjugates are presented for the purpose of investigating adenosine 5′‐[γ‐ferrocenoylalkyl] triphosphate (1 a–4 a, ferrocene (Fc)–ATP) as co‐substrates for phosphorylation reactions. Compounds 1 a–4 a were synthesized, purified by HPLC, and characterized by NMR spectroscopy and mass spectrometry. In solution, all Fc–ATP bioconjugates exhibit a reversible one‐electron redox process with a half‐wave potential (E1/2) in the 390–430 mV range, peak separations (ΔEp) in the 40–70 mV range, and the peak current ratio (ipa/ipc) near unity. The peptide‐modified surface Glu‐Gly‐Ile‐Tyr‐Asp‐Val‐Pro was used to study the sarcoma‐related protein (Src) kinase activity by employing the Fc–ATP bioconjugates as co‐substrates. Subsequent kinase‐catalyzed transfer of the γ‐Fc‐phosphate group to the tyrosine residues of the surface‐bound peptides was characterized by a formal potential (Eo) ≈390 mV (vs. Ag/AgCl). The Fc‐coverage, estimated by time‐of‐flight secondary‐ion mass spectrometry (TOF‐SIMS) and cyclic voltammetry (CV), suggested validity of Fc–ATP conjugates as kinase co‐substrates. Depending on the length of the alkyl spacer of the Fc–ATP conjugate, different current densities were obtained, pointing to a direct correlation between the two. Molecular modeling revealed that the structural constraint imposed by the short alkyl spacer (1 a) causes a steric congestion and negatively affects the outcome of phosphorylation reaction. An optimal analytical response was obtained with the Fc–ATP conjugates with linker lengths longer than six CH2 groups.
Carbon Nanotube–Nucleobase Hybrids: Nanorings from Uracil‐Modified Single‐Walled Carbon Nanotubes
Authors: Singh Prabhpreet , Toma Francesca Maria , Kumar Jitendra , Venkatesh V. , Raya Jesus , Prato Maurizio , Verma Sandeep , Bianco Alberto 
Published: May 2011

AbstractSingle‐walled carbon nanotubes (SWCNTs) have been covalently functionalized with uracil nucleobase. The hybrids have been characterized by using complementary spectroscopic and microscopic techniques including solid‐state NMR spectroscopy. The uracil‐functionalized SWCNTs are able to self‐assemble into regular nanorings with a diameter of 50–70 nm, as observed by AFM and TEM. AFM shows that the rings do not have a consistent height and thickness, which indicates that they may be formed by separate bundles of CNTs. The simplest model for the nanoring formation likely involves two bundles of CNTs interacting with each other via uracil–uracil base‐pairing at both CNT ends. These nanorings can be envisaged for the development of advanced electronic circuits.
An alert correlation platform for memory‐supported techniques
Authors: Roschke Sebastian , Cheng Feng , Meinel Christoph 
Published: May 2011

SUMMARYIntrusion Detection Systems (IDS) have been widely deployed in practice for detecting malicious behavior on network communication and hosts. False‐positive alerts are a popular problem for most IDS approaches. The solution to address this problem is to enhance the detection process by correlation and clustering of alerts. To meet the practical requirements, this process needs to be finished fast, which is a challenging task as the amount of alerts in large‐scale IDS deployments is significantly high. We identifytextitdata storage and processing algorithms to be the most important factors influencing the performance of clustering and correlation. We propose and implement a highly efficient alert correlation platform. For storage, a column‐based database, an In‐Memory alert storage, and memory‐based index tables lead to significant improvements of the performance. For processing, algorithms are designed and implemented which are optimized for In‐Memory databases, e.g. an attack graph‐based correlation algorithm. The platform can be distributed over multiple processing units to share memory and processing power. A standardized interface is designed to provide a unified view of result reports for end users. The efficiency of the platform is tested by practical experiments with several alert storage approaches, multiple algorithms, as well as a local and a distributed deployment. Copyright © 2011 John Wiley & Sons, Ltd.
The Interplay between ππ*/nπ* Excited States in Gas‐Phase Thymine: A Quantum Dynamical Study
Authors: Picconi David , Barone Vincenzo , Lami Alessandro , Santoro Fabrizio , Improta Roberto 
Published: May 2011

AbstractA quantum mechanical study of the interplay between the bright ππ* (Sπ) and the dark nπ* (Sn) excited states of thymine in the gas phase is reported. TD‐PBE0 calculations indicate that within a relevant region of the Sπ surface, connecting the Franck–Condon point with the planar and non‐planar Sπ plateau, Sπ and Sn are almost isoenergetic and that a Sπ→Sn population transfer is therefore likely. This latter process has been studied by two complementary quantum dynamical approaches, a three‐dimensional anharmonic (quartic) model, and a full‐dimensional harmonic linear vibronic coupling model. Although providing slightly different quantitative indications, both approaches predict a very fast and effective Sπ→Sn population transfer: already at 50 fs the Sn state is significantly populated (20–40 %) and this population persists or even increases on a longer time scale.
A Confidence Level Algorithm for the Determination of Absolute Configuration Using Vibrational Circular Dichroism or Raman Optical Activity
Authors: Debie Elke , De Gussem Ewoud , Dukor Rina K. , Herrebout Wouter , Nafie Laurence A. , Bultinck Patrick 
Published: May 2011

AbstractSpectral comparison is an important part of the assignment of the absolute configuration (AC) by vibrational circular dichroism (VCD), or equally by Raman optical activity (ROA). In order to avoid bias caused by personal interpretation, numerical methods have been developed to compare measured and calculated spectra. Using a neighbourhood similarity measure, the agreement between a computed and measured VCD or ROA spectrum is expressed numerically to introduce a novel confidence level measure. This allows users of vibrational optical activity (VOA) techniques (VCD and ROA) to assess the reliability of their assignment of the AC of a compound. To that end, a database of successful AC determinations is compiled along with neighbourhood similarity values between the experimental spectrum and computed spectra for both enantiomers. For any new AC determination, the neighbourhood similarities between the experimental spectrum and the computed spectra for both enantiomers are projected on the database allowing an interpretation of the reliability of their assignment.
Hole‐Burning Spectra of m‐Fluorophenol/Ammonia (1:3) Clusters and Their Excited State Hydrogen Transfer Dynamics
Authors: Tsuji Norihiro , Ishiuchi Shun‐ichi , Jouvet Christophe , Dedonder‐Lardeux Claude , Miyazaki Mitsuhiko , Sakai Makoto , Fujii Masaaki 
Published: May 2011

AbstractHole‐burning spectra of m‐fluorophenol/ammonia (1:3) clusters are measured by four‐color UV‐near IR‐UV‐UV hole‐burning spectroscopy. Cis and trans isomers of the cluster are clearly distinguished in the (1:3) cluster. Picosecond time evolutions of the excited state hydrogen transfer (ESHT) reaction in the (1:3) clusters are measured by the ion depletion due to 3p–3s Rydberg transition of reaction products ⋅NH4(NH3)2 lying in the near infrared region. From the wavelength dependence of the time evolution, we have concluded 1) the initial formation of a metastable ⋅NH4–NH3–NH3 radical and 2) successive isomerization to the most stable NH3–⋅NH4–NH3 radical in both cis and trans isomers. The reaction lifetimes of ESHT are determined by the rate equation analysis as 32.4 and 31.8 ps for the cis and trans isomer, respectively, and the isomerization and its back‐reaction lifetime of both isomers are determined to be 3.3 ps and 11.2 ps. The almost same reaction rates are consistent with the similarity of the hydrogen bond networks in both clusters.
Towards generalized ID‐based user authentication for mobile multi‐server environment
Authors: Chuang Yun‐Hsin , Tseng Yuh‐Min 
Published: May 2011

SUMMARYWith the popularity of Internet and wireless networks, more and more network architectures are used in multi‐server environment, in which mobile users remotely access servers through open networks. In the past, many schemes have been proposed to solve the issue of user authentication for multi‐server environment and low‐power mobile devices. However, most of these schemes have suffered from many attacks because these schemes did not provide the formal security analysis. In this paper, we first give a security model for multi‐server environment. We then propose an ID‐based mutual authentication and key agreement scheme based on bilinear maps for mobile multi‐server environment. Our scheme can be used for both general users with a long validity period and anonymous users with a short validity period. Under the presented security model, we show that our scheme is secure against all known attacks. We demonstrate that the proposed scheme is well suitable for low‐power mobile devices. Copyright © 2011 John Wiley & Sons, Ltd.
Ectoplasm, ghost in the R cell machine?
Authors: Xia Hongai , Ready Donald F. 
Published: May 2011

AbstractDrosophila photoreceptors (R cells) are an extreme instance of sensory membrane amplification via apical microvilli, a widely deployed and deeply conserved operation of polarized epithelial cells. Developmental rotation of R cell apices aligns rhabdomere microvilli across the optical axis and enables enormous membrane expansion in a new, proximal distal dimension. R cell ectoplasm, the specialized cortical cytoplasm abutting the rhabdomere is likewise enormously amplified. Ectoplasm is dominated by the actin‐rich terminal web, a conserved operational domain of the ancient vesicle‐transport motor, Myosin V. R cells harness Myosin V to move two distinct cargoes, the biosynthetic traffic that builds the rhabdomere during development, and the migration of pigment granules that mediates the adaptive “longitudinal pupil” in adults, using two distinct Rab proteins. Ectoplasm further shapes a distinct cortical endosome compartment, the subrhabdomeral cisterna (SRC), vital to normal cell function. Reticulon, a protein that promotes endomembrane curvature, marks the SRC. R cell visual arrestin 2 (Arr2) is predominantly cytoplasmic in dark‐adapted photoreceptors but on illumination it translocates to the rhabdomere, where it quenches ongoing photosignaling by binding to activated metarhodopsin. Arr2 translocation is “powered” by diffusion; a motor is not required to move Arr2 and ectoplasm does not obstruct its rapid diffusion to the rhabdomere. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 71: 1246‐1257, 2011
Dicer is required for the maintenance of notch signaling and gliogenic competence during mouse retinal development
Authors: Georgi Sean A. , Reh Thomas A. 
Published: May 2011

AbstractMicroRNAs (miRNAs) are 19–25 nucleotide RNAs that regulate messenger RNA translation and stability. Recently, we performed a conditional knockout (CKO) of the miRNA‐processing enzyme Dicer during mouse retinal development and showed an essential role for miRNAs in the transition of retinal progenitors from an early to a late competence state (Georgi and Reh [2010]: J Neurosci 30:4048–4061). Notably, Dicer CKO progenitors failed to express Ascl1 and generated ganglion cells beyond their normal competence window. Because Ascl1 regulates multiple Notch signaling components, we hypothesized that Notch signaling is downregulated in Dicer CKO retinas. We show here that Notch signaling is severely reduced in Dicer CKO retinas, but that retinal progenitors still retain a low level of Notch signaling. By increasing Notch signaling in Dicer CKO progenitors through constitutive expression of the Notch intracellular domain (NICD), we show that transgenic rescue of Notch signaling has little effect on the competence of retinal progenitors or the enhanced generation of ganglion cells, suggesting that loss of Notch signaling is not a major determinant of these phenotypes. Nevertheless, transgenic NICD expression restored horizontal cells, suggesting an interaction between miRNAs and Notch signaling in the development of this cell type. Furthermore, while NICD overexpression leads to robust glial induction in control retinas, NICD overexpression was insufficient to drive Dicer‐null retinal progenitors to a glial fate. Surprisingly, the presence of transgenic NICD expression did not prevent the differentiation of some types of retinal neurons, suggesting that Notch inactivation is not an absolute requirement for the initial stages of neuronal differentiation. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 71: 1153‐1169, 2011
Fear of food as a treatment target: Exposure and response prevention for anorexia nervosa in an open series
Authors: Steinglass Joanna , Albano Anne Marie , Simpson H. Blair , Carpenter Kenneth , Schebendach Janet , Attia Evelyn 
Published: May 2011

AbstractObjective:Anorexia nervosa (AN) is a severe mental illness with high rates of relapse and rehospitalization. New treatment approaches are needed. We aimed to evaluate the potential utility of addressing eating‐related fear in the treatment of AN using psychotherapy techniques known to be effective in the treatment of anxiety disorders and obsessive compulsive disorder, namely exposure therapy and response prevention.Method:We developed a brief treatment intervention for AN (AN‐EXRP) and evaluated its effects in an open series of nine individuals with AN towards the end of acute weight restoration. We focused on eating behavior as the primary outcome, as it is related both to anxiety and to longer term course.Results:Change in anxiety with AN‐EXRP was associated with greater caloric intake.Discussion:These findings support the anxiety‐centered model of AN and suggest the potential utility of further developing this treatment approach. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)
Stereoselective Syntheses of Aza, Amino and Imino Sugar Derivatives by Hydroboration of 3,6‐Dihydro‐2H‐1,2‐oxazines as Key Reaction
Authors: Dekaris Vjekoslav , Pulz Robert , Al‐Harrasi Ahmed , Lentz Dieter , Reissig Hans‐Ulrich 
Published: May 2011

AbstractStarting from enantiopure 3,6‐dihydro‐2H‐1,2‐oxazinessyn‐1 we introduced an additional hydroxy group in a stereoselective fashion by a standard hydroboration/oxidation protocol. Under “regular“ conditions substrate control was sufficient to achieve a very high degree of stereoselectivity. However, a diastereomeric product was isolated when a partially “degraded” borane reagent was used. We could synthesise this new diastereomer on purpose by addition of alcohols to the “fresh“ hydroboration reagent. The level of stereoinduction increased with the steric bulk of the added alcohol: MeOH < nBuOH < iPrOH < tBuOH. After a two‐step oxidation/reduction sequence, another 5‐hydroxy‐1,2‐oxazine epimer was accessible. The obtained 5‐hydroxy‐1,2‐oxazine diastereomers 2 were used as versatile intermediates in a series of transformations leading to several amino polyol derivatives. Complete deprotection of both diastereomers without cleavage of the N–O bond led to the novel polyhydroxylated tetrahydro‐2H‐1,2‐oxazines 3 and epi‐3. By change of the deprotection conditions the open‐chain amino polyol 4 with D‐iditol configuration became accessible. In an alternative sequence 5‐hydroxy‐1,2‐oxazines were utilised to synthesise imino sugars (polyhydroxylated pyrrolidines). Samarium diiodide induced cleavage of the 1,2‐oxazine N–O bond furnished 1,4‐amino alcohols, which were cyclised to give the corresponding pyrrolidine derivatives after activation by mesyl chloride. This sequence either led to a 3‐methoxy‐substituted trihydroxylated pyrrolidine derivative or to the related fully deprotected compound.
Gold(I)‐Catalyzed Reactions of Propargyl Esters with Vinyl Derivatives
Authors: Sperger Christian A. , Tungen Jørn E. , Fiksdahl Anne 
Published: May 2011

AbstractA gold‐catalyzed olefin cyclopropanation reaction of propargyl esters with vinyl ester or vinyl sulfonamide derivatives was investigated for the synthesis of highly substituted cyclopropane derivatives in good diastereoselectivity. By varying the vinyl species, trans‐cyclopentenyl esters were selectively formed by a formal [3+2] cycloaddition.
Microwave‐Promoted Palladium‐Catalysed Oxyarylation of Dihydronaphthalene and Chromenes by o‐Iodophenols and Its Acetates
Authors: Leão Raquel A. C. , Pinho Vagner D. , Coelho Artur S. , Buarque Camilla D. , Moraes Paula F. , Alonso Diego A. , Nájera Carmen , Costa Paulo R. R. 
Published: May 2011

AbstractThe oxyarylation of dihydronaphthalene (1a), two electron‐rich (1b,c) and one electron‐poor (2) chromenes with different o‐iodophenols and their acetates 3a–h has been investigated by using either Pd(OAc)2 (10 mol‐%) as precatalyst and Ag2CO3 as base in acetone as solvent or oxime palladacycle 5 as precatalyst and dicyclohexylamine as base in DMA/H2O. The reactions, which were strongly accelerated under microwave heating, afforded the best yields when electron‐rich chromenes reacted with o‐iodophenols substituted by electron‐withdrawing groups in the presence Pd(OAc)2 and Ag2CO3. However, in the case of electron‐poor chromenes the best yield was obtained with the electron‐rich o‐iodophenol 3g.
Talking about visually perceived events: Communication effects on eyewitness memory
Authors: Hellmann Jens H. , Echterhoff Gerald , Kopietz René , Niemeier Sarah , Memon Amina 
Published: May 2011

AbstractCommunicators' tuning of a message about a social target to their audience's evaluation can shape their representation of the target. This audience‐tuning effect has been demonstrated with ambiguous text passages as input material. We examined whether the effect also occurs when communicators learn about the target's behaviours from visual (nonverbal) input material. In Experiment 1, participants watched a soundless video depicting ambiguous behaviours of a target, described the video to an audience who liked (vs. disliked) the target, and subsequently recalled the video. Both message and recall were biased towards the audience's judgement. In Experiment 2, the video depicted a forensically relevant event, specifically ambiguous behaviours of two persons involved in a bar brawl. Participants tuned their event retellings to their audience's responsibility judgement and remembered the event accordingly. In both experiments, the effect of the audience's judgement on recall was statistically mediated by the extent to which the message was tuned to the audience. The more participants experienced a shared reality with their audience the stronger was the message‐recall correlation (Experiment 2). We conclude that the audience‐tuning effect for visually perceived information depends on the communicators' creation of a shared reality with their audience. Copyright © 2011 John Wiley & Sons, Ltd.
Sensitive and Selective Detection of Dopamine Using a DNA Immobilized Ethylenedidamine/Polyglutamic Modified Electrode
Authors: Zou Lina , Luo Peili , Li Yamin , Zhang Shusheng , Ye Baoxian 
Published: May 2011

AbstractDNA was attached on the surface of an ethylenedidamine/polyglutamic(En/PGA) modified glassy carbon electrode (GCE) to create a novel voltammetric sensor (DNA/En/PGA/GCE) for dopamine (DA). This modified electrode exhibited a linear voltammetric response for DA in the range from 1.0×10−7 mol L−1 to 1×10−5 mol L−1, with a detection limit of 2×10−8 mol L−1. The detection of DA was found to be unaffected by the presence of ascorbic acid, uric acid, serotonin and folic acid. The method proposed was applied to detect DA in pharmaceutical dosage and human blood serum with good satisfactory results.
Use of multiple reaction monitoring for multiplex analysis of colorectal cancer‐associated proteins in human feces
Authors: Ang Ching‐Seng , Rothacker Julie , Patsiouras Heather , Gibbs Peter , Burgess Antony W. , Nice Edouard C. 
Published: May 2011

AbstractColorectal cancer (CRC) is the second most common cause of cancer‐related deaths worldwide with an annual incidence of almost a million cases and an annual mortality around 500 000. The fecal occult blood test is currently the first line method for CRC screening, but has unacceptably low sensitivity and specificity. Improved screening tests are therefore urgently required for early‐stage CRC screening when therapy is most likely to be effective. We describe a discovery‐based proteomics hypothesis using orthogonal multi‐dimensional fractionation (1‐D SDS‐PAGE, RP‐HPLC, size exclusion chromatography) to mine deep into the fecal proteome for the initial discovery process, which generated a library containing 108 human fecal proteins with the associated peptide and MS/MS data. These data were then used to develop and optimize a multiplex multiple reaction monitoring assay for 40 non‐redundant human proteins present in the feces. To show proof of principal for clinical analysis, multiplex screening of these 40 proteins was carried out on fecal samples from eight CRC patient and seven normal volunteers. We identified 24 proteins consistently found in all samples and nine proteins found only in the CRC patients, showing the potential of this approach for the analysis of potential CRC biomarkers. Absolute quantitation using C‐terminal isotopically labeled synthetic peptides corresponding to hemoglobin and carcinoembryonic antigen 5 was also performed.