bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nucleolipids of the Cancerostatic 5‐Fluorouridine: Synthesis, Adherence to Oligonucleotides, and Incorporation in Artificial Lipid Bilayers
Authors: Malecki Edith , Ottenhaus Vanessa , Werz Emma , Knies Christine , Montilla Martinez Malayko , Rosemeyer Helmut 
Published: February 2014

Abstract5‐Fluorouridine (1a) was converted to its N(3)‐farnesylated nucleoterpene derivative 8 by direct alkylation with farnesyl bromide (4). Reaction of the cancerostatic 1a with either acetone, heptan‐4‐one, nonadecan‐10‐one, or hentriacontan‐16‐one afforded the 2′,3′‐O‐ketals 2a–2d. Compound 2b was then first farnesylated (→5) and subsequently phosphitylated to give the phosphoramidite 6. The ketal 2c was directly 5′‐phosphitylated without farnesylation of the base to give the phosphoramidite 7. Moreover, the recently prepared cyclic 2′,3′‐O‐ketal 11 was 5′‐phosphitylated to yield the phosphoramidite 12. The 2′,3′‐O‐isopropylidene derivative 2a proved to be too labile to be converted to a phosphoramidite. All novel derivatives of 1a were unequivocally characterized by NMR and UV spectroscopy and ESI mass spectrometry, as well as by elemental analyses. The lipophilicity of the phosphoramidite precursors were characterized by both their retention times in RP‐18 HPLC and by calculated log P values. The phosphoramidites 6, 7, and 12 were exemplarily used for the preparation of four terminally lipophilized oligodeoxynucleotides carrying a cyanine‐3 or a cyanine‐5 residue at the 5′‐(n–1) position (i.e., 14–17). Their incorporation in an artificial lipid bilayer was studied by single‐molecule fluorescence spectroscopy and fluorescence microscopy.
On Dioxygen Permeation through a Dehydrogenase‐Pyrroloquinoline Quinone Complex. A Molecular‐Dynamics Investigation
Authors: Pietra Francesco 
Published: February 2014

AbstractIn this work, an all atom model of the quinoprotein dehydrogenase PqqC in complex with the PQQ (=4,5‐dihydro‐4,5‐dioxo‐1H‐pyrrolo[2,3‐f]quinoline‐2,7,9‐tricarboxylic acid) cofactor and dioxygen (O2), solvated with TIP3 water in periodic boxes, was subjected to random‐acceleration molecular dynamics (RAMD). It was found that O2 leaves the active binding pocket, in front of PQQ, to get to the solvent, as easily as with a variety of other O2‐activating enzymes, O2 carriers, and gas‐sensing proteins. The shortest pathway, orthogonal to the center of the mean plane of PQQ, was largely preferred by O2 over pathways slightly deviating from this line. These observations challenge the interpretation of an impermeable active binding pocket of PqqC‐PQQ, as drawn from both X‐ray diffraction data of the crystal at low temperature and physiological experimentation.
The perivascular niche governs an autoregulatory network to support breast cancer metastasis
Authors: Fazilaty Hassan , Behnam Babak 
Published: February 2014

AbstractUnravelling the autoregulatory network that induces and maintains cancer stem cell state may provide novel effective therapies against breast cancer metastasis. The perivascular niche develops elements that initiate the autoregulatory machine to induce and maintain cancer stem cells, but not EMT, among newly arrived tumour cells. Inhibition of one or more primary key elements that trigger this circuit may result in the prevention or cure of breast cancer metastasis.
Nitric oxide donor NOC‐5 increases XIAP and Aven level in Jurkat cells
Authors: Starikova Elena G. , Tashireva L. A. , Novitsky V. V. , Ryazantseva N. V. 
Published: February 2014

AbstractMitochondrial permeabilisation after NO donor application did not activate caspase‐9. We have studied the X‐linked apoptosis inhibitor (XIAP) and Aven protein content in NO‐treated Jurkat cells. The level of both proteins increased in NO‐treated cells. Thus the increase in XIAP and Aven content could be the cause of the lack of caspase‐9 activity after mitochondrial permeabilisation in NO‐treated Jurkat cells.
LIMD1 antagonizes E2F1 activity and cell cycle progression by enhancing Rb function in cancer cells
Authors: Mayank Adarsh K. , Sharma Shipra , Deshwal Ravi K , Lal Sunil K. 
Published: February 2014

AbstractTumour suppressor genes restrain inappropriate cell growth and division, as well as stimulate cell death to maintain tissue homeostasis. Loss of function leads to abnormal cellular behaviour, including hyperproliferation of cell and perturbation of cell cycle regulation. LIMD1 is a tumour suppressor gene located at chromosome 3p21.3, a region commonly deleted in many solid malignancies. LIMD1 interacts with retinoblastoma (Rb) and is involved in Rb‐mediated downregulation of E2F1‐target genes. However, the role of LIMD1 in cell cycle regulation remains unclear. We propose that LIMD1 induces cell cycle arrest, utilising Rb‐E2F1 axis, and show that ectopic expression of LIMD1 in A549 cells results in hypo‐phosphorylation that potentiates Rb function, which correlates with downregulation of E2F1. In agreement with these observations, LIMD1 overexpression retards cell cycle progression and blocks S‐phase entry, as cells accumulate in G0/G1 phase and have reduced incorporation of BrdU. Most significantly, LIMD1‐dependent effects on Rb function and cell cycle are reversed on depletion of endogenous LIMD1, underscoring its centrality in Rb‐mediated cell cycle regulation. Hence, our findings provide new insight into cell cycle control by Rb‐LIMD1 nexus.
Executive function and mothering: Challenges faced by teenage mothers
Authors: Chico Elsie , Gonzalez Andrea , Ali Nida , Steiner Meir , Fleming Alison S. 
Published: February 2014

ABSTRACTPrevious research has established that in comparison to adult mothers teen mothers respond less sensitively to their infants. In adults, components of executive functions relate directly to maternal sensitivity. Since teenagers are known to have a less developed prefrontal cortex and greater difficulties in parenting, this study sought to determine whether the association between executive processes and mothering exists among teenagers. Two groups of mothers, teens (n = 30) and adults (n = 27), who were approximately 4–6 months postpartum, completed tasks assessing spatial working memory and attentional set shifting (cognitive flexibility) using the Cambridge Neuropsychological Test Automated Battery. Mothers were videotaped interacting with their infants and were later coded for various maternal behaviors. As predicted, teenagers performed more poorly than adults on tasks of cognitive flexibility and were less sensitive in their infant interactions. Among both groups there was a negative association between executive function and mothering; however, depending on the age of the mother different executive function tasks were relevant. © 2014 Wiley Periodicals, Inc. Dev Psychobiol 56: 1027–1035, 2014.
Long‐term influences of a preterm birth on movement organization and side specialization in children at 4–8 years of age
Authors: Johansson Anna‐Maria , Domellöf Erik , Rönnqvist Louise 
Published: February 2014

ABSTRACTThis study explored upper‐limb and head kinematics during unimanual goal‐directed movements in children born preterm (PT) and full‐term (FT) aged 4–8 years. Further, functional lateralization was investigated through side‐specific kinematics and hand preference observations. Altogether, 141 children were included, divided into three sub‐groups based on gestation week at birth (GW). Children born FT (38–41 GW) and moderately PT (33–35 GW) showed faster, smoother, and shorter movement trajectories than children born very PT (V‐PT < 33 GW). Only children born FT expressed evident side differences that were characterized by smoother movements with the preferred side. Regarding hand preference, the children born V‐PT showed increased rates of non‐right‐handedness compared with the other groups. Regardless of hand preference, the children born V‐PT showed less well organized movements compared with the other groups. These findings suggest that spatio‐temporal movement organization and side specialization at pre‐/early school‐age are affected by a PT birth, and more frequently so for children born before 33 GWs, indicating long‐lasting influences on neuromotor development and specialization. © 2014 Wiley Periodicals, Inc. Dev Psychobiol 56: 1263–1277, 2014.
Life history mediates mate limitation and population viability in self‐incompatible plant species
Authors: Thrall Peter H. , Encinas‐Viso Francisco , Hoebee Susan E. , Young Andrew G. 
Published: February 2014

AbstractGenetically controlled self‐incompatibility systems represent links between genetic diversity and plant demography with the potential to directly impact on population dynamics. We use an individual‐based spatial simulation to investigate the demographic and genetic consequences of different self‐incompatibility systems for plants that vary in reproductive capacity and lifespan. The results support the idea that, in the absence of inbreeding effects, populations of self‐incompatible species will often be smaller and less viable than self‐compatible species, particularly for shorter‐lived organisms or where potential fecundity is low. At high ovule production and low mortality, self‐incompatible and self‐compatible species are demographically similar, thus self‐incompatibility does not automatically lead to reduced mate availability or population viability. Overall, sporophytic codominant self‐incompatibility was more limiting than gametophytic or sporophytic dominant systems, which generally behaved in a similar fashion. Under a narrow range of conditions, the sporophytic dominant system maintained marginally greater mate availability owing to the production ofSlocus homozygotes. While self‐incompatibility reduces population size and persistence for a broad range of conditions, the actual number ofSalleles, beyond that required for reproduction, is important for only a subset of life histories. For these situations, results suggest that addition of newSalleles may result in significant demographic rescue.
Extraordinary MHC class II B diversity in a non‐passerine, wild bird: the Eurasian Coot Fulica atra (Aves: Rallidae)
Authors: Alcaide Miguel , Muñoz Joaquin , Martínez‐de la Puente Josué , Soriguer Ramón , Figuerola Jordi 
Published: February 2014

AbstractThe major histocompatibility complex (MHC) hosts the most polymorphic genes ever described in vertebrates. The MHC triggers the adaptive branch of the immune response, and its extraordinary variability is considered an evolutionary consequence of pathogen pressure. The last few years have witnessed the characterization of the MHC multigene family in a large diversity of bird species, unraveling important differences in its polymorphism, complexity, and evolution. Here, we characterize the first MHC class II B sequences isolated from a Rallidae species, the Eurasian Coot Fulica atra. A next‐generation sequencing approach revealed up to 265 alleles that translated into 251 different amino acid sequences (β chain, exon 2) in 902 individuals. Bayesian inference identified up to 19 codons within the presumptive peptide‐binding region showing pervasive evidence of positive, diversifying selection. Our analyses also detected a significant excess of high‐frequency segregating sites (average Tajima's D = 2.36, P < 0.05), indicative of balancing selection. We found one to six different alleles per individual, consistent with the occurrence of at least three MHC class II B gene duplicates. However, the genotypes comprised of three alleles were by far the most abundant in the population investigated (49.4%), followed by those with two (29.6%) and four (17.5%) alleles. We suggest that these proportions are in agreement with the segregation of MHC haplotypes differing in gene copy number. The most widespread segregating haplotypes, according to our findings, would contain one single gene or two genes. The MHC class II of the Eurasian Coot is a valuable system to investigate the evolutionary implications of gene copy variation and extensive variability, the greatest ever found, to the best of our knowledge, in a wild population of a non‐passerine bird.
Synthesis of Ionic‐Liquid‐Supported Diaryliodonium Salts
Authors: Kumar Muthyala Manoj , Choudhary Sunita , Pandey Khima , Shelke Ganesh M. , Jha Mukund , Kumar Anil 
Published: February 2014

AbstractThe synthesis of ionic‐liquid‐supported diaryliodonium salts is described. The synthesis is simple and practical, and the ionic liquid products require no chromatographic purification. The ionic‐liquid‐supported diaryliodonium salts are quite stable, and they did not show any sign of decomposition or loss of reactivity, even after being stored for one month at 5 °C. The reactivity of these salts was explored in the phenylation of substituted phenols and carboxylic acids, and the corresponding diaryl ethers and aryl esters, respectively, were synthesized in good to excellent yields and with high purities.
Durability Testing of a High‐Temperature Steam Electrolyzer Stack at 700 °C
Authors: Fu Q. , Schefold J. , Brisse A. , Nielsen J. U. 
Published: February 2014

AbstractA 5‐cell solid oxide electrolyzer cell (SOEC) stack has been operated at ca. 700 °C for 2,000 h under static conditions followed by a short‐term transient operation. The best repeating unit (RU) showed an area specific resistance of 0.4 Ω cm2 and an initial voltage of 1.125 V at 705 °C and –0.6 A cm–2 when fed with 90% H2O/10% H2 at the hydrogen‐electrode. One instability factor has been observed, which led to dramatic voltage fluctuations for most RUs in the stack. Such kind of voltage fluctuation is correlated predominantly to the variation of ohmic resistances of RUs, pointing out most probably unstable electrical contact in the stack under the present testing conditions. Disregarding the worst RU (RU1), the average degradation rate (voltage increase rate) of all RUs in the stack has been determined to be around 2% kh–1 (24 mV kh–1) for the last 500 h of static operation free of voltage fluctuations. The stack showed no noticeable degradation during the short‐term transient operation (totally 756 ON/OFF current cycles), indicating preliminarily that it could be possible to couple intermittent power sources with high‐temperature steam electrolyzers.
Influence of Deposition Temperature of GDC Interlayer Deposited by RF Magnetron Sputtering on Anode‐Supported SOFC
Authors: Wu W. , Wang X. , Liu Z. , Zhao Z. , Ou D. , Tu B. , Cheng M. 
Published: February 2014

AbstractGadolinia‐doped ceria (GDC) film, as a barrier layer to prevent chemical reaction between yttria‐stabilized zirconia (YSZ) electrolyte and Ba0.5Sr0.5Co0.8Fe0.2O3–δ (BSCF)–GDC cathode, is deposited by radio frequency (RF) magnetron sputtering on YSZ electrolyte, and the influence of deposition temperature on Ni–YSZ/YSZ/GDC/BSCF–GDC single cell performance is investigated. The SEM results show that the GDC film deposited at 30 °C exhibits a porous structure, whereas the GDC film deposited at 400 °C has a dense structure. The single cells show excellent performance when the deposition temperature is above 250 °C, whereas the single cells show poor performance when the deposition temperature is below 200 °C. The large difference in cell performance occurs from their large difference in polarization resistance. The porous structure of GDC interlayer, which cannot well prevent the reaction between BSCF and YSZ, is responsible for the poor performance of the cells with GDC interlayer deposited at a temperature below 200 °C.
SOFC Cell Design Optimization Using the Finite Element Method Based CFD Approach
Authors: Andersson M. , Yuan J. , Sundén B. 
Published: February 2014

AbstractFuel cells are hopeful for future energy systems, because they are energy efficient and able to use renewable fuels. A coupled computational fluid dynamics approach based on the finite element method, in three‐dimensions, is used to illustrate a planar intermediate‐temperature solid oxide fuel cell. Governing equations for momentum, gas‐phase species, heat, electron and ion transport are implemented and coupled to kinetics describing electrochemical reactions. Three different cell designs are compared in a parametric study. The importance of the cathode support layer is revealed, because this layer significantly decreases the oxygen gas‐phase resistance within the cathode (at positions under the interconnect ribs) in the direction normal to the cathode/electrolyte interface as well as the electron resistance inside the cathode (at positions under the air channel) in the same direction. It is concluded that wider and thinner gas channels enable a more compact design with only a slightly decreased cell current density (per cross‐sectional electrode/electrolyte interface area), i.e. a considerably increased volumetric cell current can be achieved.
Networked Graphitic Structures as Durable Catalyst Support for PEM Electrodes
Authors: Negro E. , Vries M. A. De , Latsuzbaia R. , Koper G. J. M. 
Published: February 2014

AbstractA PFSA‐stabilized Pt‐catalyst supported on a novel carbon material, carbon nano networks (CNNs), was synthesized. To benchmark its performance, it was compared to a commercial catalyst, supported on an amorphous carbon support, and to a PFSA stabilized Pt catalyst supported on commercial carbon nano tubes (CNTs). The PFSA‐Pt/CNNs exhibit improved performance compared to commercial catalysts in terms of ORR kinetic activity and durability. Even though PFSA‐Pt/CNTs should show comparable behavior to PFSA‐Pt/CNNs, our experimental results show a slightly superior performance. Optimization of the CNN synthesis route is expected to improve their properties as a carbon support. Since CNN mass production is expected to be cheaper than for CNTs because of the simplicity of the synthesis route, we conclude that CNNs are a promising material for the fuel cell market.
An interaction platform for mechanized tunnelling. Application on the Wehrhahn‐Line in Düsseldorf (Germany) / Eine Interaktionsplattform für maschinelle Tunnelvortriebe. Anwendung am Beispiel der Wehrhahn‐Linie in Düsseldorf
Authors: Schindler Steffen , Hegemann Felix , Alsahly Abdullah , Barciaga Thomas , Galli Mario , Lehner Karlheinz , Koch Christian 
Published: February 2014

AbstractThis paper introduces a holistic product model for the interactive simulation of shield tunnelling machines. The underlying product model is based on the Building Information Modelling methodology and uses the Industry Foundation Classes to classify and structure the captured data. Data from design, measurements and numerical simulation components obtained from four sub‐models (ground, tunnel, tunnel boring machine and building) are stored, classified and organized on commonly available servers. The very heterogeneous data structures found in each individual model are adjusted in advance using georeferencing, transformation or other suitable methods to increase compatibility. In particular, this article describes the methodological design of an interactive product model for mechanized tunnelling in soft soil, including its sub‐models. Performance is demonstrated by a case study using data from the Wehrhahn‐Line subway construction site in Düsseldorf, Germany. Here, the focus is on the verification of the product model and its use in the numerical simulations. The research presented is a central component of the Collaborative Research Center SFB 837 “Interaction Modelling in Mechanized Tunnelling” at the Ruhr University, Bochum.Zur interaktiven Simulation von maschinellen Schildvortrieben wird ein ganzheitliches Produktmodell vorgestellt. Das Produktmodell basiert auf der Methode des Building Information Modelings und nutzt zur Strukturierung der Daten das Datenaustauschformat Industry Foundation Classes (IFC). Zentral gespeicherte Daten aus Planung, Messungen oder numerischen Simulationen von insgesamt vier Untermodellen (Baugrund, Tunnel, Tunnelvortriebsmaschine und Bebauung) werden klassifiziert und wiederum zur weiteren Nutzung organisiert. Die sehr heterogene Datenstruktur der einzelnen Untermodelle wird im Vorfeld durch Georeferenzierung, Transformation und andere geeignete Verfahren angepasst. Der Beitrag beschreibt den methodischen Aufbau des interaktiven Produktmodells für den Tunnelvortrieb im Lockergestein einschließlich seiner Untermodelle. Die Leistungsfähigkeit zeigt ein Fallbeispiel mit Daten der U‐Bahnbaustelle Wehrhahn‐Linie in Düsseldorf. Hierbei liegt der Schwerpunkt auf der Verifizierung des Produktmodells sowie auf verknüpften Simulationen und übergreifenden Analysen. Die Forschungsarbeiten sind zentraler Bestandteil des Sonderforschungsbereichs SFB 837 “Interaktionsmodelle für den maschinellen Tunnelbau” an der Ruhr‐Universität Bochum.
A Simple Synthesis of Polyfunctionalized 4‐Aminopyrazolidin‐3‐ones as ‘Aza‐deoxa’ Analogs of D‐Cycloserine
Authors: Novak Ana , Štefanič Matej , Grošelj Uroš , Hrast Martina , Kasunič Marta , Gobec Stanislav , Stanovnik Branko , Svete Jurij 
Published: February 2014

AbstractA simple five‐step synthesis of fully substituted (4RS,5RS)‐4‐aminopyrazolidin‐3‐ones as analogs of D‐cycloserine was developed. It comprises a two‐step preparation of 5‐substituted (4RS,5RS)‐4‐(benzyloxycarbonylamino)pyrazolidin‐3‐ones, reductive alkylation at N(1), alkylation of the amidic N(2) with alkyl halides, and simultaneous hydrogenolytic deprotection/reductive alkylation of the primary NH2 group. The synthesis enables an easy stepwise functionalization of the pyrazolidin‐3‐one core with only two types of common reagents, aldehydes (or ketones) and alkyl halides. The structures of products were elucidated by NMR spectroscopy and X‐ray diffraction.