bluuebunny/crossref_metadata_2025_split huggingface dataset:
Von Disilen (SiSi) über Phosphasilen (SiP) zum Phosphakumulen (PCN)
Authors: Willmes Philipp , Cowley Michael J. , Hartmann Marco , Zimmer Michael , Huch Volker , Scheschkewitz David 
Published: January 2014

AbstractDie Erzeugung schwerer Doppelbindungssysteme ohne Bildung von Koppel‐ oder Nebenprodukten ist von großer Bedeutung für deren Anwendung in der Synthese. Periphere funktionelle Gruppen sind in dieser Hinsicht wegen der ihnen eigenen Mobilität vielversprechend. In Anhängigkeit vom sterischen Anspruch des N‐Alkylsubstituenten R ergibt die Reaktion des Disilenids Ar2SiSi(Ar)Li (Ar=2,4,6‐iPr3C6H2) mit Chlorphosphanen ClP(NR2)2 entweder das Phosphinodisilen Ar2SiSi(Ar)P(NR2)2 (für R=iPr) oder P‐aminofunktionalisierte Phosphasilene Ar2(R2N)SiSi(Ar)P(NR2) (für R=Et, Me) über 1,3‐Verschiebung einer der Aminogruppen. Im Fall von R=Me erfolgt nach Zugabe eines Äquivalents tert‐Butylisocyanid eine zweite Aminogruppenwanderung zum 1‐Aza‐3‐phosphaallen Ar2(R2N)SiSi(NR2)(Ar)PCNtBu mit ausgeprägtem Ylid‐Charakter. Alle neuen Verbindungen wurden durch Multikern‐NMR‐Spektroskopie vollständig charakterisiert, zusätzlich in ausgewählten Fällen durch Einkristall‐Röntgenbeugung und DFT‐Rechnungen.
Real‐Time Monitoring of New Delhi Metallo‐β‐Lactamase Activity in Living Bacterial Cells by 1H NMR Spectroscopy
Authors: Ma Junhe , McLeod Sarah , MacCormack Kathleen , Sriram Shubha , Gao Ning , Breeze Alexander L. , Hu Jun 
Published: January 2014

AbstractDisconnections between in vitro responses and those observed in whole cells confound many attempts to design drugs in areas of serious medical need. A method based on 1D 1H NMR spectroscopy is reported that affords the ability to monitor the hydrolytic decomposition of the carbapenem antibiotic meropenem inside Escherichia coli cells expressing New Delhi metallo‐β‐lactamase subclass 1 (NDM‐1), an emerging antibiotic‐resistance threat. Cell‐based NMR studies demonstrated that two known NDM‐1 inhibitors, L‐captopril and ethylenediaminetetraacetic acid (EDTA), inhibit the hydrolysis of meropenem in vivo. NDM‐1 activity in cells was also shown to be inhibited by spermine, a porin inhibitor, although in an in vitro assay, the influence of spermine on the activity of isolated NDM‐1 protein is minimal. This new approach may have generic utility for monitoring reactions involving diffusible metabolites in other complex biological matrices and whole‐cell settings, including mammalian cells.
Arrays of polyacrylamide hydrogels using a carbodiimide‐mediated crosslinking reaction
Authors: Sheng Qi , Tian Wendy , Lapierre Florian , Gao Song , Mulder Roger J. , Zhu Yonggang , Kozielski Karen A. , Wood Colin D. 
Published: January 2014

ABSTRACTThis study introduces a radical‐free approach for generating polyacrylamide (PAM) hydrogels with no toxic residues remaining in the networks. Acrylamide and bisacrylamide, which are neurotoxins, are not used during the hydrogel synthesis and only nontoxic side products are generated. This is achieved using a gentle carbodiimide‐mediated crosslinking (CMCL) reaction that does not require complex initiation systems and is effective in the presence of oxygen. This overcomes some of the key limitations related to PAM hydrogel synthesis using free‐radical routes and maintains the advantages of synthetic hydrogels over biopolymers. In addition, the CMCL reaction allows for accurate placement of functional groups, which controls hydrogel structure and performance including mechanical strength, swelling capacity, and hydrophobic balance. This flexibility is demonstrated through the synthesis and rheological characterization of a library of structurally diverse hydrogels as well as spherical hydrogels. PAM‐based hydrogels are used extensively in a broad number of applications, and this study demonstrates the applicability of this method as a nontoxic and radical‐free complementary alternative route that can generate structures analogous to those prepared using free‐radical routes. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40416.
Exploring the mechanism how Marburg virus VP35 recognizes and binds dsRNA by molecular dynamics simulations and free energy calculations
Authors: Xue Qiao , Zheng Qing‐Chuan , Zhang Ji‐Long , Cui Ying‐Lu , Zhang Hong‐Xing 
Published: January 2014

ABSTRACTFiloviruses often cause terrible infectious disease which has not been successfully dealt with pharmacologically. All filoviruses encode a unique protein termed VP35 which can mask doubled‐stranded RNA to deactivate interferon. The interface of VP35–dsRNA would be a feasible target for structure‐based antiviral agent design. To explore the essence of VP35–dsRNA interaction, molecular dynamics simulation combined with MM‐GBSA calculations were performed on Marburg virus VP35–dsRNA complex and several mutational complexes. The energetic analysis indicates that nonpolar interactions provide the main driving force for the binding process. Although the intermolecular electrostatic interactions play important roles in VP35–dsRNA interaction, the whole polar interactions are unfavorable for binding which result in a low binding affinity. Compared with wild type VP35, the studied mutants F228A, R271A, and K298A have obviously reduced binding free energies with dsRNA reflecting in the reduction of polar or nonpolar interactions. The results also indicate that the loss of binding affinity for one dsRNA strand would abolish the total binding affinity. Three important residues Arg271, Arg294, and Lys298 which makes the largest contribution for binding in VP35 lose their binding affinity significantly in mutants. The uncovering of VP35–dsRNA recognition mechanism will provide some insights for development of antiviral drug. © 2014 Wiley Periodicals, Inc. Biopolymers 101: 849–860, 2014.
Determination of mazindol in human oral fluid by high performance liquid chromatography–electrospray ionization mass spectrometry
Authors: de Oliveira Marcella Herbstrith , Carlos Graciela , Bergold Ana Maria , Pechansky Flavio , Limberger Renata Pereira , Fröehlich Pedro Eduardo 
Published: January 2014

ABSTRACTBrazil is one of the countries most affected by abuse of stimulant medications by professional drivers, especially fenproporex, amfepramone and mazindol. Even though their sale is banned, they can be found in illegal markets, such as those located on the country's borders. The use of oral fluid to monitor drug levels has many advantages over plasma and urine because it is noninvasive, easier to collect and more difficult to adulterate. The aim of this study was to develop and validate a sensitive and specific method to quantify mazindol in human oral fluid by liquid chromatography–mass spectrometry (LC‐MS). The LC system consisted of an LC‐MS system operated in selected ion monitoring mode. The mobile phase was composed of water at pH 4.0, acetonitrile and methanol (60:15:25 v/v/v) at a flow rate of 1.0 mL/min and propranolol was used as internal standard. Total running time was 10 min. The lower limit of quantification was 0.2 ng/mL and the method exhibited good linearity within the 0.2–20 ng/mL range (r = 0.9987). A rapid, specific, sensitive, linear, precise and accurate method was developed for determination of mazindol in human oral fluid according to European Medicines Agency guidelines, and is suitable for monitoring mazindol levels in oral fluid of professional drivers. Copyright © 2014 John Wiley & Sons, Ltd.
Through Thick and Thin? How Self‐determination Drives the Corporate Sustainability Initiatives of Multinational Subsidiaries
Authors: Shah Kalim U. , Arjoon Surendra 
Published: January 2014

AbstractMultinational corporation (MNC) subsidiaries implement corporate sustainability initiatives (CSIs) if they are self‐determined to do so (based on intrinsic motivation) or when urged on by circumstances and pressures (based on extrinsic motivation). Such differences in self‐determination are derived from underlying corporate psychological needs for competence, autonomy and relatedness, and are manifested in the governance choices of making, allying or buying CSIs. In this study of oil and gas MNC subsidiaries in the developing country context of Trinidad and Tobago, four distinct types of firm are identified based on their levels of self‐determination and corporate governance tendencies. These groups are identified as trail blazers, marching soldiers, sharp shooters and fire fighters, and their distinctive characteristics are described. These findings are useful to corporate sustainability strategists seeking to select, design and implement CSIs that satisfy MNC headquarter directives but balance subsidiary objectives of maintaining good relations and access to operate in developing countries. Copyright © 2014 John Wiley & Sons, Ltd and ERP Environment
Brand preference affects the threshold for perceptual awareness
Authors: Ramsøy Thomas Zoëga , Skov Martin 
Published: January 2014

ABSTRACTDespite decades of scientific scrutiny, much is still unknown about the effects that brands have on perception. Brands are known to lead to changes in attention and mnemonic processing and by altering emotional preferences they imbue products with value. Less, however, is known about the exact mechanism through which this occurs. Here, a novel and unexpected finding is provided in which subjective brand preference alters the likelihood that a brand name will be consciously seen. By presenting brand names at brief durations, and having them respond using a graded evaluation of conscious perception, the Perception Awareness Scale, it is found that brand names for which there is either a positive and negative preference, subjects report seeing the name more clearly. Interestingly, and much to the contrary of studies of basic emotions, this effect is strongest for positive preference. Our results are discussed in light of other studies in consumer psychology and consciousness science. Copyright © 2013 John Wiley & Sons, Ltd.
3‐Substituted Indazoles as Configurationally Locked 4EGI‐1 Mimetics and Inhibitors of the eIF4E/eIF4G Interaction
Authors: Yefidoff‐Freedman Revital , Chen Ting , Sahoo Rupam , Chen Limo , Wagner Gerhard , Halperin Jose A. , Aktas Bertal H. , Chorev Michael 
Published: January 2014

Abstract4EGI‐1, the prototypic inhibitor of eIF4E/eIF4G interaction, was identified in a high‐throughput screening of small‐molecule libraries with the aid of a fluorescence polarization assay that measures inhibition of binding of an eIF4G‐derived peptide to recombinant eIF4E. As such, the molecular probe 4EGI‐1 has potential for the study of molecular mechanisms involved in human disorders characterized by loss of physiological restraints on translation initiation. A hit‐to‐lead optimization campaign was carried out to overcome the configurational instability in 4EGI‐1, which stems from the E‐to‐Z isomerization of the hydrazone function. We identified compound 1 a, in which the labile hydrazone was incorporated into a rigid indazole scaffold, as a promising rigidified 4EGI‐1 mimetic lead. In a structure–activity relationship study directed towards probing the structural latitude of this new chemotype as an inhibitor of eIF4E/eIF4G interaction and translation initiation we identified 1 d, an indazole‐based 4EGI‐1 mimetic, as a new and improved lead inhibitor of eIF4E/eIF4G interaction and a promising molecular probe candidate for elucidation of the role of cap‐dependent translation initiation in a host of pathophysiological states.
A Deadly Organometallic Luminescent Probe: Anticancer Activity of a ReI Bisquinoline Complex
Authors: Kitanovic Igor , Can Suzan , Alborzinia Hamed , Kitanovic Ana , Pierroz Vanessa , Leonidova Anna , Pinto Antonio , Spingler Bernhard , Ferrari Stefano , Molteni Roberto , Steffen Andreas , Metzler‐Nolte Nils , Wölfl Stefan , Gasser Gilles 
Published: January 2014

AbstractThe photophysical properties of [Re(CO)3(L‐N3)]Br (L‐N3=2‐azido‐N,N‐bis[(quinolin‐2‐yl)methyl]ethanamine), which could not be localized in cancer cells by fluorescence microscopy, have been revisited in order to evaluate its use as a luminescent probe in a biological environment. The ReI complex displays concentration‐dependent residual fluorescence besides the expected phosphorescence, and the nature of the emitting excited states have been evaluated by DFT and time‐dependent (TD) DFT methods. The results show that fluorescence occurs from a 1LC/MLCT state, whereas phosphorescence mainly stems from a 3LC state, in contrast to previous assignments. We found that our luminescent probe, [Re(CO)3(L‐N3)]Br, exhibits an interesting cytotoxic activity in the low micromolar range in various cancer cell lines. Several biochemical assays were performed to unveil the cytotoxic mechanism of the organometallic ReI bisquinoline complex. [Re(CO)3(L‐N3)]Br was found to be stable in human plasma indicating that [Re(CO)3(L‐N3)]Br itself and not a decomposition product is responsible for the observed cytotoxicity. Addition of [Re(CO)3(L‐N3)]Br to MCF‐7 breast cancer cells grown on a biosensor chip micro‐bioreactor immediately led to reduced cellular respiration and increased glycolysis, indicating a large shift in cellular metabolism and inhibition of mitochondrial activity. Further analysis of respiration of isolated mitochondria clearly showed that mitochondrial respiratory activity was a direct target of [Re(CO)3(L‐N3)]Br and involved two modes of action, namely increased respiration at lower concentrations, potentially through increased proton transport through the inner mitochondrial membrane, and efficient blocking of respiration at higher concentrations. Thus, we believe that the direct targeting of mitochondria in cells by [Re(CO)3(L‐N3)]Br is responsible for the anticancer activity.
Neighboring Residue Effects in Terminally Blocked Dipeptides: Implications for Residual Secondary Structures in Intrinsically Unfolded/Disordered Proteins
Authors: Jung Young‐Sang , Oh Kwang‐Im , Hwang Geum‐Sook , Cho Minhaeng 
Published: January 2014

ABSTRACTFor nuclear magnetic resonance (NMR)‐based protein structure determinations, the random coil chemical shifts are very important because the secondary and tertiary protein structure predictions become possible by examining deviations of measured chemical shifts from those reference chemical shift values. In addition, neighboring residue effects on chemical shifts and J‐coupling constants are crucial in understanding the nature of conformational propensities exhibited by unfolded or intrinsically disordered proteins. We recently reported the 1D NMR results for a complete set of terminally blocked dipeptides (Oh KI, Jung YS, Hwang GS, Cho M. J Biomol NMR 2012;53:25–41), but the NMR resonance assignments were not possible so that the average chemical shifts and J‐coupling constants were only considered. In the present work, to thoroughly investigate the neighboring residue effects and random coil chemical shifts we extend the previous studies with 2D NMR, and measured all the 3JHNHα values and Hα and HN chemical shifts of the same set of terminally blocked dipeptides that are free from structural effects like secondary structure, hydrogen‐bond, long‐range backbone, and side‐chain interactions. In particular, the preceding and following residue effects on amino‐acid backbone conformational propensities are revealed and directly compared with previous works on either short peptides or empirical chemical shift database. Chirality 26:443‐452, 2014. © 2014 Wiley Periodicals, Inc.
The Catalytic Pathways of Hydrohalogenation over Metal‐Free Nitrogen‐Doped Carbon Nanotubes
Authors: Zhou Kai , Li Bo , Zhang Qiang , Huang Jia‐Qi , Tian Gui‐Li , Jia Jin‐Chao , Zhao Meng‐Qiang , Luo Guo‐Hua , Su Dang Sheng , Wei Fei 
Published: January 2014

AbstractNitrogen‐doped carbon nanotubes (N‐CNTs) are found to be active as one novel heterogeneous catalyst for acetylene hydrochlorination reaction, possessing good activity (TOF=2.3×10−3 s−1) and high selectivity (>98 %). Compared to toxic and energy‐consuming conventional catalysts, such as HgCl2, N‐CNTs are more favorable in terms of sustainability, because of their thermo‐stability, metal‐free make up, and the wide availability of bulk CNT. Coupling X‐ray photoelectron spectroscopy and density functional theory computations (DFT), the main active source and reaction pathway are shown. Good linearity between the quaternary nitrogen content and conversion is revealed. DFT study shows that the nitrogen doping enhanced the formation of the covalent bond between C2H2 and NCNT compared with the undoped CNT, and therefore promoted the addition reaction of the C2H2 and HCl into C2H3Cl.
Concomitant evaluation of PMA+ionomycin‐induced kinase phosphorylation and cytokine production in T cell subsets by flow cytometry
Authors: Crawford Timothy Q. , Jalbert Emilie , Ndhlovu Lishomwa C. , Barbour Jason D. 
Published: January 2014

AbstractMethods to detect intracellular kinase signaling intermediates by flow cytometry have been recently developed. Termed “phospho‐flow,” these methods employ fluorescence‐conjugated monoclonal antibodies that recognize phosphorylated epitopes of intracellular kinases, and may be combined with surface phenotypic markers to observe changes in kinase pathways by cellular subset. Effector functions, like cytokine production, are processes intrinsically linked to intracellular signaling and kinase activity within each cell. Methodologies that would simultaneously detect changes to signaling pathways as well as effector responses at the single‐cell level would allow for mapping of the functional consequences induced by signaling pathway modifications. However, there are challenges to developing such a combined protocol, relating to the different kinetics of rapid signaling events and the more prolonged time required to induce and observe cytokine responses. In this report, we describe the development of an assay that accommodates differences in protocol conditions and response kinetics, merging phospho‐flow cytometry, and intracellular cytokine staining methods into a single experimental protocol. We examined intracellular ERK1/2 phosphorylation and IFN‐γ production by CD4+ and CD8+ T cells upon polyclonal stimulation with PMA and ionomycin, while monitoring expression of the cytolytic molecule perforin and the T cell activation marker CD38. We present a method that allows observation of kinase phosphorylation and cytokine production within the same cell after stimuli, while maintaining a stable cellular phenotype. Monitoring of signaling and effector functions in distinct immune subsets provides a platform to investigate and relate intracellular kinase signaling activity to immune cell effector function and phenotype in disease states. © 2014 International Society for Advancement of Cytometry
Do you “like” my photo? Facebook use maintains eating disorder risk
Authors: Mabe Annalise G. , Forney K. Jean , Keel Pamela K. 
Published: January 2014

ABSTRACTObjectiveSocial media sites, such as Facebook, merge two factors that influence risk for eating disorders: media and peers. Previous work has identified cross‐sectional and temporal associations between Facebook use and disordered eating. This study sought to replicate and extend these findings using an experimental design.MethodIn Study 1, 960 women completed self‐report surveys regarding Facebook use and disordered eating. In Study 2, 84 women were randomly assigned to use Facebook or to use an alternate internet site for 20 min.ResultsMore frequent Facebook use was associated with greater disordered eating in a cross‐sectional survey. Facebook use was associated with the maintenance of weight/shape concerns and state anxiety compared to an alternate internet activity.DiscussionFacebook use may contribute to disordered eating by maintaining risk for eating pathology. As such, targeting Facebook use may be helpful in intervention and prevention programs. © 2014 Wiley Periodicals, Inc. (Int J Eat Disord 2014; 47:516–523)
Increased plasma level of soluble urokinase plasminogen activator receptor is associated with incidence of heart failure but not atrial fibrillation
Authors: Borné Yan , Persson Margaretha , Melander Olle , Smith J. Gustav , Engström Gunnar 
Published: January 2014

AimsSoluble urokinase plasminogen activator receptor (suPAR) in plasma is a novel inflammatory marker thought to be released from the cell surface of neutrophils, T cells, and macrophages. Other inflammatory markers, mainly acute phase proteins produced in the liver, have been associated with the incidence of heart failure (HF) and atrial fibrillation (AF). We investigated the association between suPAR and incident HF and AF in a population‐based cohort.Methods and resultsSoluble urokinase plasminogen activator receptor was measured in 4530 subjects (aged 46–68 years, 61% women), who participated in the Malmö Diet and Cancer study during 1991–1996. Incident cases of HF and AF were identified from the Swedish hospital discharge register during a median follow‐up of 16.3 years. During follow‐up, 109 subjects (55% men) were diagnosed with new‐onset HF and 321 individuals (50% men) with AF. suPAR was significantly associated with increased plasma levels of NT‐proBNP (P < 0.001). suPAR was significantly associated with incidence of HF [hazard ratio (HR) for the third vs. first tertile 3.33, 95% confidence interval (CI) 1.91–5.81 after adjustment for age and sex; and HR 1.82, 95% CI 1.02–3.27, P for trend 0.018 after adjustment for conventional risk factors and biomarkers]. suPAR was significantly associated with incidence of AF, when adjusted for age and sex (HR 1.40, 95% CI 1.06–1.85). However, this relationship was non‐significant after adjustment for conventional risk factors and biomarkers.ConclusionSoluble urokinase plasminogen activator receptor was associated with increased plasma levels of NT‐proBNP and incidence of HF, but not with AF among middle‐aged subjects.
Hybrid phospholipid bilayer coatings for separations of cationic proteins in capillary zone electrophoresis
Authors: Gallagher Elyssia S. , Adem Seid M. , Bright Leonard K. , Calderon Isen A. C. , Mansfield Elisabeth , Aspinwall Craig A. 
Published: January 2014

Protein separations in CZE suffer from nonspecific adsorption of analytes to the capillary surface. Semipermanent phospholipid bilayers have been used to minimize adsorption, but must be regenerated regularly to ensure reproducibility. We investigated the formation, characterization, and use of hybrid phospholipid bilayers (HPBs) as more stable biosurfactant capillary coatings for CZE protein separations. HPBs are formed by covalently modifying a support with a hydrophobic monolayer onto which a self‐assembled lipid monolayer is deposited. Monolayers prepared in capillaries using 3‐cyanopropyldimethylchlorosilane (CPDCS) or n‐octyldimethylchlorosilane (ODCS) yielded hydrophobic surfaces with lowered surface free energies of 6.0 ± 0.3 or 0.2 ± 0.1 mJ m−2, respectively, compared to 17 ± 1 mJ m−2 for bare silica capillaries. HPBs were formed by subsequently fusing vesicles comprised of 1,2‐dilauroyl‐sn‐glycero‐3‐phosphocholine or 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine to CPDCS‐ or ODCS‐modified capillaries. The resultant HPB coatings shielded the capillary surface and yielded reduced electroosmotic mobility (1.3–1.9 × 10−4 cm2 V−1s−1) compared to CPDCS‐ and ODCS‐modified or bare capillaries (3.6 ± 0.2 × 10−4 cm2 V−1s−1, 4.8 ± 0.4 × 10−4 cm2 V−1s−1, and 6.0 ± 0.2 × 10−4 cm2 V−1s−1, respectively), with increased stability compared to phospholipid bilayer coatings. HPB‐coated capillaries yielded reproducible protein migration times (RSD ≤ 3.6%, n ≥ 6) with separation efficiencies as high as 200 000 plates/m.