bluuebunny/crossref_metadata_2025 huggingface dataset:
Claudin-2-dependent paracellular channels are dynamically gated
Authors: Weber Christopher R , Liang Guo Hua , Wang Yitang , Das Sudipto , Shen Le , Yu Alan S L , Nelson Deborah J , Turner Jerrold R
Published: November 2015

Intercellular tight junctions form selectively permeable barriers that seal the paracellular space. Trans-tight junction flux has been measured across large epithelial surfaces, but conductance across individual channels has never been measured. We report a novel trans-tight junction patch clamp technique that detects flux across individual claudin-2 channels within the tight junction of cultured canine renal tubule or human intestinal epithelial monolayers. In both cells, claudin-2 channels display conductances of ~90 pS. The channels are gated, strictly dependent on claudin-2 expression, and display size- and charge-selectivity typical of claudin-2. Kinetic analyses indicate one open and two distinct closed states. Conductance is symmetrical and reversible, characteristic of a passive, paracellular process, and blocked by reduced temperature or site-directed mutagenesis and chemical derivatization of the claudin-2 pore. We conclude that claudin-2 forms gated paracellular channels and speculate that modulation of tight junction channel gating kinetics may be an unappreciated mechanism of barrier regulation.
TANGO1 recruits ERGIC membranes to the endoplasmic reticulum for procollagen export
Authors: Santos António JM , Raote Ishier , Scarpa Margherita , Brouwers Nathalie , Malhotra Vivek
Published: November 2015

Previously we showed that membrane fusion is required for TANGO1-dependent export of procollagen VII from the endoplasmic reticulum (ER) (Nogueira, et al., 2014). Along with the t-SNARE Syntaxin 18, we now reveal the complete complement of SNAREs required in this process, t-SNAREs BNIP1 and USE1, and v-SNARE YKT6. TANGO1 recruits YKT6-containing ER Golgi Intermediate Compartment (ERGIC) membranes to procollagen VII-enriched patches on the ER. Moreover residues 1214-1396, that include the first coiled coil of TANGO1, specifically recruit ERGIC membranes even when targeted to mitochondria. TANGO1 is thus pivotal in concentrating procollagen VII in the lumen and recruiting ERGIC membranes on the cytoplasmic surface of the ER. Our data reveal that growth of a mega transport carrier for collagen export from the ER is not by acquisition of a larger patch of ER membrane, but instead by addition of ERGIC membranes to procollagen-enriched domains of the ER by a TANGO1-mediated process.
Burst muscle performance predicts the speed, acceleration, and turning performance of Anna’s hummingbirds
Authors: Segre Paolo S , Dakin Roslyn , Zordan Victor B , Dickinson Michael H , Straw Andrew D , Altshuler Douglas L
Published: November 2015

Despite recent advances in the study of animal flight, the biomechanical determinants of maneuverability are poorly understood. It is thought that maneuverability may be influenced by intrinsic body mass and wing morphology, and by physiological muscle capacity, but this hypothesis has not yet been evaluated because it requires tracking a large number of free flight maneuvers from known individuals. We used an automated tracking system to record flight sequences from 20 Anna's hummingbirds flying solo and in competition in a large chamber. We found that burst muscle capacity predicted most performance metrics. Hummingbirds with higher burst capacity flew with faster velocities, accelerations, and rotations, and they used more demanding complex turns. In contrast, body mass did not predict variation in maneuvering performance, and wing morphology predicted only the use of arcing turns and high centripetal accelerations. Collectively, our results indicate that burst muscle capacity is a key predictor of maneuverability.
Excitation and inhibition onto central courtship neurons biases Drosophila mate choice
Authors: Kallman Benjamin R , Kim Heesoo , Scott Kristin
Published: November 2015

The ability to distinguish males from females is essential for productive mate selection and species propagation. Recent studies in Drosophila have identified different classes of contact chemosensory neurons that detect female or male pheromones and influence courtship decisions. Here, we examine central neural pathways in the male brain that process female and male pheromones using anatomical, calcium imaging, optogenetic, and behavioral studies. We find that sensory neurons that detect female pheromones, but not male pheromones, activate a novel class of neurons in the ventral nerve cord to cause activation of P1 neurons, male-specific command neurons that trigger courtship. In addition, sensory neurons that detect male pheromones, as well as those that detect female pheromones, activate central mAL neurons to inhibit P1. These studies demonstrate that the balance of excitatory and inhibitory drives onto central courtship-promoting neurons controls mating decisions.
Sexually divergent expression of active and passive conditioned fear responses in rats
Authors: Gruene Tina M , Flick Katelyn , Stefano Alexis , Shea Stephen D , Shansky Rebecca M
Published: November 2015

Traditional rodent models of Pavlovian fear conditioning assess the strength of learning by quantifying freezing responses. However, sole reliance on this measure includes the de facto assumption that any locomotor activity reflects an absence of fear. Consequently, alternative expressions of associative learning are rarely considered. Here we identify a novel, active fear response (‘darting’) that occurs primarily in female rats. In females, darting exhibits the characteristics of a learned fear behavior, appearing during the CS period as conditioning proceeds and disappearing from the CS period during extinction. This finding motivates a reinterpretation of rodent fear conditioning studies, particularly in females, and it suggests that conditioned fear behavior is more diverse than previously appreciated. Moreover, rats that darted during initial fear conditioning exhibited lower freezing during the second day of extinction testing, suggesting that females employ distinct and adaptive fear response strategies that improve long-term outcomes.
Structure of the mantle beneath the Alboran Basin from magnetotelluric soundings
Authors: Garcia X. , Seillé H. , Elsenbeck J. , Evans R. L. , Jegen M. , Hölz Sebastian , Ledo J. , Lovatini A. , Marti A. , Marcuello A. , Queralt P. , Ungarelli C. , Ranero C. R.
Published: November 2015

We present results of marine MT acquisition in the Alboran sea that also incorporates previously acquired land MT from southern Spain into our analysis. The marine data show complex MT response functions with strong distortion due to seafloor topography and the coastline, but inclusion of high resolution topography and bathymetry and a seismically defined sediment unit into a 3‐D inversion model has allowed us to image the structure in the underlying mantle. The resulting resistivity model is broadly consistent with a geodynamic scenario that includes subduction of an eastward trending plate beneath Gibraltar, which plunges nearly vertically beneath the Alboran. Our model contains three primary features of interest: a resistive body beneath the central Alboran, which extends to a depth of ∼150 km. At this depth, the mantle resistivity decreases to values of ∼100 Ohm‐m, slightly higher than those seen in typical asthenosphere at the same depth. This transition suggests a change in slab properties with depth, perhaps reflecting a change in the nature of the seafloor subducted in the past. Two conductive features in our model suggest the presence of fluids released by the subducting slab or a small amount of partial melt in the upper mantle (or both). Of these, the one in the center of the Alboran basin, in the uppermost‐mantle (20–30 km depth) beneath Neogene volcanics and west of the termination of the Nekkor Fault, is consistent with geochemical models, which infer highly thinned lithosphere and shallow melting in order to explain the petrology of seafloor volcanics.
Spontaneous reconnection at a separator current layer: 1. Nature of the reconnection
Authors: Stevenson J. E. H. , Parnell C. E.
Published: November 2015

Magnetic separators, which lie on the boundary between four topologically distinct flux domains, are prime locations in three‐dimensional magnetic fields for reconnection, especially in the magnetosphere between the planetary and interplanetary magnetic fields and also in the solar atmosphere. Little is known about the details of separator reconnection, and so the aim of this paper, which is the first of two, is to study the properties of magnetic reconnection at a single separator. Three‐dimensional, resistive magnetohydrodynamic numerical experiments are run to study separator reconnection starting from a magnetohydrostatic equilibrium which contains a twisted current layer along a single separator linking a pair of opposite‐polarity null points. The resulting reconnection occurs in two phases. The first is short involving rapid reconnection in which the current at the separator is reduced by a factor of around 2.3. Most (75%) of the magnetic energy is converted during this phase, via Ohmic dissipation, directly into internal energy, with just 0.1% going into kinetic energy. During this phase the reconnection occurs along most of the separator away from its ends (the nulls) but in an asymmetric manner which changes both spatially and temporally over time. The second phase is much longer and involves slow impulsive bursty reconnection. Again, Ohmic heating dominates over viscous damping. Here the reconnection occurs in small localized bursts at random anywhere along the separator.
Observation and simulation of lake‐air heat and water transfer processes in a high‐altitude shallow lake on the Tibetan Plateau
Authors: Wang Binbin , Ma Yaoming , Chen Xuelong , Ma Weiqiang , Su Zhongbo , Menenti Massimo
Published: November 2015

Lakes are an important part of the landscape on the Tibetan Plateau. Most of the Plateau lakes' area has been expanding in recent years, but lake‐atmosphere energy and water interaction is poorly understood because of a lack of observational data and adequate modeling systems. Based on the eddy covariance observation over a high‐altitude shallow and small lake (the small Nam Co Lake) during an ice‐free period from 10 April to 30 August 2012, this study analyzes the lake‐air heat and water vapor turbulent transfer processes and evaluates two popular lake‐air exchange models: a bulk aerodynamic transfer model (B model) and a multilayer model (M model). Our main results are as follows: (1) observations show that the bulk transfer coefficient (CE) and roughness length (zoq) for water are higher than those for heat (CH and z0h), especially under low wind speed; (2) both models underestimate turbulent fluxes due to inaccurate values of the Charnock coefficient (α) and the roughness Reynolds number (Rr) which are both important parameters for calculating the roughness length for momentum (z0m) over water; (3) α within a reasonable range of 0.013–0.035 for rough flow and Rr for smooth flow (Rr = 0.11) are 0.031 and 0.54, respectively, by our observation. The wave pattern of shorter wavelength gives a larger z0m in the small and shallow lake; and (4) the B model and the M model gave consistent results, and both models are more suitable for simulation of turbulent flux exchange after z0m optimization.
Analysis of groundwater flow in mountainous, headwater catchments with permafrost
Authors: Evans Sarah G. , Ge Shemin , Liang Sihai
Published: November 2015

Headwater catchments have a direct impact on the water resources of downstream lowland regions as they supply freshwater in the form of surface runoff and discharging groundwater. Often, these mountainous catchments contain expansive permafrost that may alter the natural topographically controlled groundwater flow system. As permafrost could degrade with climate change, it is imperative to understand the effect of permafrost on groundwater flow in headwater catchments. This study characterizes groundwater flow in mountainous headwater catchments and evaluates the effect of permafrost in the context of climate change on groundwater movement using a three‐dimensional, finite element, hydrogeologic model. The model is applied to a representative headwater catchment on the Qinghai‐Tibet Plateau, China. Results from the model simulations indicate that groundwater contributes significantly to streams in the form of baseflow and the majority of groundwater flow is from the shallow aquifer above the permafrost, disrupting the typical topographically controlled flow pattern observed in most permafrost‐free headwater catchments. Under a warming scenario where mean annual surface temperature is increased by 2°C, reducing the areal extent of permafrost in the catchment, groundwater contribution to streamflow may increase three‐fold. These findings suggest that, in headwater catchments, permafrost has a large influence on groundwater flow and stream discharge. Increased annual air temperatures may increase groundwater discharge to streams, which has implications for ecosystem health and the long‐term availability of water resources to downstream regions.
“This lifetime commitment”: Public conceptions of disability and noninvasive prenatal genetic screening
Authors: Steinbach Rosemary J. , Allyse Megan , Michie Marsha , Liu Emily Y. , Cho Mildred K.
Published: November 2015

Recently, new noninvasive prenatal genetic screening technologies for Down syndrome and other genetic conditions have become commercially available. Unique characteristics of these screening tests have reignited long‐standing concerns about prenatal testing for intellectual and developmental disabilities. We conducted a web‐based survey of a sample of the US public to examine how attitudes towards disability inform views of prenatal testing in the context of these rapidly advancing prenatal genetic screening technologies. Regardless of opinion toward disability, the majority of respondents supported both the availability of screening and the decision to continue a pregnancy positive for aneuploidy. Individuals rationalized their support with various conceptions of disability; complications of the expressivist argument and other concerns from the disability literature were manifested in many responses analyzed. © 2015 Wiley Periodicals, Inc.
Triploidy mosaicism (45,X/68,XX) in an infant presenting with failure to thrive
Authors: Posey Jennifer E. , Mohrbacher Nikki , Smith Janice L. , Patel Ankita , Potocki Lorraine , Breman Amy M.
Published: November 2015

Triploid mosaicism is a rare aneuploidy syndrome characterized by growth retardation, developmental delay, 3–4 syndactyly, microphthalmia, coloboma, cleft lip and/or palate, genitourinary anomalies, and facial or body asymmetry. In the present report, we describe a 3‐month‐old female presenting with failure to thrive, growth retardation, and developmental delay. A chromosomal microarray demonstrated monosomy X, but her atypical phenotype prompted further evaluation with a chromosome analysis, which demonstrated 45,X/68,XX mixoploidy. To our knowledge, this is the first report of a patient with this chromosome complement. Mosaicism in chromosomal aneuploidies is likely under‐recognized and may obscure the clinical diagnosis. At a time when comparative genomic hybridization and genome sequencing are increasingly used as diagnostic tools, this report highlights the clinical utility of chromosome analysis when a molecular diagnosis is not consistent with the observed phenotype. © 2015 Wiley Periodicals, Inc.
Does refining the phenotype improve replication rates? A review and replication of candidate gene studies on Major Depressive Disorder and Chronic Major Depressive Disorder
Authors: Luo Xiaochen , Stavrakakis Nikolaos , Penninx Brenda W. , Bosker Fokko J. , Nolen Willem A. , Boomsma Dorret I. , de Geus Eco J. , Smit Johan H. , Snieder Harold , Nolte Ilja M. , Hartman Catharina A.
Published: November 2015

Replication has been poor for previously reported candidate genes involved in Major Depressive Disorder (MDD). One possible reason is phenotypic and genetic heterogeneity. The present study replicated genetic associations with MDD as defined in DSM‐IV and with a more narrowly defined MDD subtype with a chronic and severe course. We first conducted a systematic review of genetic association studies on MDD published between September 2007 and June 2012 to identify all reported candidate genes. Genetic associations were then tested for all identified single nucleotide polymorphisms (SNPs) and the entire genes using data from the GAIN genome‐wide association study (MDD: n = 1,352; chronic MDD subsample: n = 225; controls: n =  1,649). The 1,000 Genomes database was used as reference for imputation. From 157 studies identified inthe literature, 81 studies reported significant associations with MDD, involving 245 polymorphisms in 97 candidate genes, from which we were able to investigate 185 SNPs in 89 genes. We replicated nine candidate SNPs in eight genes for MDD and six in five genes for chronic MDD. However, these were not more than expected by chance. At gene level, we replicated 18 genes for MDD and 17 genes for chronic MDD, both significantly more than expected by chance. We showed that replication rates were improved for MDD compared to a previous, highly similar, replication study based on studies published before 2007. Effect sizes of the SNPs and replication rates of the candidate genes were improved in the chronic subsample compared to the full sample. Nonetheless, replication rates were still poor. © 2015 Wiley Periodicals, Inc.
Testing the association between human mid‐facial morphology and climate using autosomal, mitochondrial, Y chromosomal polymorphisms and cranial non‐metrics
Authors: Evteev Andrej A. , Movsesian Alla A.
Published: November 2015

Objectives

To figure out which and how many systems of genetic markers should be used to control for the effects of shared population history in studies examining the association between morphology and climate and to test cranial non‐metric traits as an additional source of neutral distances for such studies.

Materials and Methods

We employed three systems of genetic markers (mtDNA, Y‐chromosome and autosomal SNPs) and cranial non‐metrics to control for potential impact of population history on apparent associations between climatic variables and mid‐facial morphology found in a set of seven North Asian and one East Asian populations.

Results

A significant association between morphology and climate remained, independent of which of the four neutral distance matrices were used as a control. Matrices of neutral distances based on different systems of genetic markers show just one case of significant correlation among each other namely between the mtDNA and autosomal SNPs matrices. The correlation between the autosomal SNP and cranial non‐metrics matrices is also fairly high but does not reach significance.

Discussion

A combination of several sources of genetic information could provide a more robust control for the effect of shared population history compared to just one type of markers since each of them has its own sources of bias and each provides a slightly different view of genetic relationships among the populations. Use of cranial non‐metrics in researches examining the association between morphology and climate appears promising as they produce results that are generally consistent with those obtained using genetic markers. Am J Phys Anthropol 159:517–522, 2016. © 2015 Wiley Periodicals, Inc.
Selektive Hemmung des Immunproteasoms durch strukturbasierte Wahl eines nichtkatalytischen Cysteins als Angriffspunkt
Authors: Dubiella Christian , Baur Regina , Cui Haissi , Huber Eva M. , Groll Michael
Published: November 2015

Klinisch genutzte Proteasominhibitoren induzieren Zelltod durch die gleichzeitige Blockade des konstitutiven Proteasoms und des Immunproteasoms. Dagegen ist die selektive Hemmung des Immunproteasoms kaum zytotoxisch, und sie könnte Anwendung in der Modulation von chronischen Entzündungen und Autoimmunkrankheiten finden. Es wurden decarboxylierte Peptide entwickelt, die mittels eines α‐Chloracetamides in einer Seitengruppe gezielt ein nichtkatalytisches Cystein in der β5i‐Untereinheit des Immunproteasoms angreifen. Die so gesteigerte Isoformspezifität resultierte in verminderten zytotoxischen Nebenwirkungen und reduzierte die Produktion von inflammatorischen Zytokinen. Strukturbasierte Optimierung führte zu einer über 150‐fachen Selektivität für die Untereinheit β5i gegenüber β5c. Diese neue Verbindungsklasse bietet einen vielversprechenden Ansatz für die Entwicklung von potenziell antiinflammatorischen Inhibitoren, die selektiv das Immunproteasom hemmen.
A Filled‐Honeycomb‐Structured Crystal Formed by Self‐Assembly of a Janus Polyoxometalate–Silsesquioxane (POM–POSS) Co‐Cluster
Authors: Ma Chi , Wu Han , Huang Zi‐Han , Guo Ruo‐Hai , Hu Min‐Biao , Kübel Christian , Yan Li‐Tang , Wang Wei
Published: November 2015

Clusters with diverse structures and functions have been used to create novel cluster‐assembled materials (CAMs). Understanding their self‐assembly process is a prerequisite to optimize their structure and function. Herein, two kinds of unlike organo‐functionalized inorganic clusters are covalently linked by a short organic tether to form a dumbbell‐shaped Janus co‐cluster. In a mixed solvent of acetonitrile and water, it self‐assembles into a crystal with a honeycomb superstructure constructed by hexagonal close‐packed cylinders of the smaller cluster and an orderly arranged framework of the larger cluster. Reconstruction of these structural features via coarse‐grained molecular simulations demonstrates that the cluster crystallization and the nanoscale phase separation between the two incompatible clusters synergistically result in the unique nano‐architecture. Overall, this work opens up new opportunities for generating novel CAMs for advanced future applications.
Reversible Inhibitoren arretieren ClpP in einer definierten Konformation, die durch Bindung von ClpX aufgehoben wird
Authors: Pahl Axel , Lakemeyer Markus , Vielberg Marie‐Theres , Hackl Mathias W. , Vomacka Jan , Korotkov Vadim S. , Stein Martin L. , Fetzer Christian , Lorenz‐Baath Katrin , Richter Klaus , Waldmann Herbert , Groll Michael , Sieber Stephan A.
Published: November 2015

Die caseinolytische Protease P ist ein wichtiger Regulator der Pathogenität von Staphylococcus aureus. Mithilfe eines Hochdurchsatz‐Screenings bezüglich der Inhibition der ClpP‐Peptidaseaktivität identifizierten wir den ersten nichtkovalenten Inhibitor dieser Enzymklasse. Die Cokristallisation der niedermolekularen Verbindung mit ClpP von S. aureus offenbarte einen neuen Bindungsmodus: Die Rotation des konservierten Prolinrests 125 arretiert ClpP in einer Konformation, in der die korrekte Ausrichtung der katalytischen Triade verhindert und damit die Peptidaseaktivität inhibiert wird. In Optimierungsstudien wurden Derivate entwickelt, die frühere ClpP‐Inhibitoren in ihrer Potenz übertreffen. Erstaunlicherweise wird die durch die Inhibitoren verursachte Blockade bei Bindung des Chaperons ClpX rückgängig gemacht. Die Verdrängung des Inhibitors durch mit ClpP assoziierte Chaperone stellt einen unvermuteten Regulationsmechanismus dar, der sich jedoch für die Entwicklung von ClpP‐Inhibitoren als entscheidend erweist.
Visualization of Vibrational Modes in Real Space by Tip‐Enhanced Non‐Resonant Raman Spectroscopy
Authors: Duan Sai , Tian Guangjun , Luo Yi
Published: November 2015

We present a general theory to model the spatially resolved non‐resonant Raman images of molecules. It is predicted that the vibrational motions of different Raman modes can be fully visualized in real space by tip‐enhanced non‐resonant Raman scattering. As an example, the non‐resonant Raman images of water clusters were simulated by combining the new theory and first‐principles calculations. Each individual normal mode gives rise its own distinct Raman image, which resembles the expected vibrational motions of the atoms very well. The characteristics of intermolecular vibrations in supermolecules could also be identified. The effects of the spatial distribution of the plasmon as well as nonlinear scattering processes were also addressed. Our study not only suggests a feasible approach to spatially visualize vibrational modes, but also provides new insights in the field of nonlinear plasmonic spectroscopy.
Triarylboron‐Based Fluorescent Organic Light‐Emitting Diodes with External Quantum Efficiencies Exceeding 20 %
Authors: Suzuki Katsuaki , Kubo Shosei , Shizu Katsuyuki , Fukushima Tatsuya , Wakamiya Atsushi , Murata Yasujiro , Adachi Chihaya , Kaji Hironori
Published: November 2015

Triarylboron compounds have attracted much attention, and found wide use as functional materials because of their electron‐accepting properties arising from the vacant p orbitals on the boron atoms. In this study, we design and synthesize new donor–acceptor triarylboron emitters that show thermally activated delayed fluorescence. These emitters display sky‐blue to green emission and high photoluminescence quantum yields of 87–100 % in host matrices. Organic light‐emitting diodes using these emitting molecules as dopants exhibit high external quantum efficiencies of 14.0–22.8 %, which originate from efficient up‐conversion from triplet to singlet states and subsequent efficient radiative decay from singlet to ground states.
Polyboramines for Hydrogen Release: Polymers Containing Lewis Pairs in their Backbone
Authors: Ledoux Audrey , Larini Paolo , Boisson Christophe , Monteil Vincent , Raynaud Jean , Lacôte Emmanuel
Published: November 2015

The one‐step polycondensation of diamines and diboranes triggered by the in situ deprotonation of the diammonium salts and concomitant reduction of bisboronic acids leads to the assembly of polymer chains through multiple Lewis pairing in their backbone. These new polyboramines are dihydrogen reservoirs that can be used for the hydrogenation of imines and carbonyl compounds. They also display a unique dihydrogen thermal release profile that is a direct consequence of the insertion of the amine–borane linkages in the polymeric backbone.
Tetraalkylammonium Salts as Hydrogen‐Bonding Catalysts
Authors: Shirakawa Seiji , Liu Shiyao , Kaneko Shiho , Kumatabara Yusuke , Fukuda Airi , Omagari Yumi , Maruoka Keiji
Published: November 2015

Although the hydrogen‐bonding ability of the α hydrogen atoms on tetraalkylammonium salts is often discussed with respect to phase‐transfer catalysts, catalysis that utilizes the hydrogen‐bond‐donor properties of tetraalkylammonium salts remains unknown. Herein, we demonstrate hydrogen‐bonding catalysis with newly designed tetraalkylammonium salt catalysts in Mannich‐type reactions. The structure and the hydrogen‐bonding ability of the new ammonium salts were investigated by X‐ray diffraction analysis and NMR titration studies.
Glycocalyx Engineering with a Recycling Glycopolymer that Increases Cell Survival In Vivo
Authors: Woods Elliot C. , Yee Nathan A. , Shen Jeff , Bertozzi Carolyn R.
Published: November 2015

Synthetic glycopolymers that emulate cell‐surface mucins have been used to elucidate the role of mucin overexpression in cancer. However, because they are internalized within hours, these glycopolymers could not be employed to probe processes that occur on longer time scales. In this work, we tested a panel of glycopolymers bearing a variety of lipids to identify those that persist on cell membranes. Strikingly, we found that cholesterylamine (CholA) anchored glycopolymers are internalized into vesicles that serve as depots for delivery back to the cell surface, allowing for the display of cell‐surface glycopolymers for at least ten days, even while the cells are dividing. As with native mucins, the cell‐surface display of CholA‐anchored glycopolymers influenced the focal adhesion distribution. Furthermore, we show that these mimetics enhance the survival of nonmalignant cells in a zebrafish model of metastasis. CholA‐anchored glycopolymers therefore expand the application of glycocalyx engineering in glycobiology.
Inverting the G‐Tetrad Polarity of a G‐Quadruplex by Using Xanthine and 8‐Oxoguanine
Authors: Cheong Vee Vee , Lech Christopher Jacques , Heddi Brahim , Phan Anh Tuân
Published: November 2015

G‐quadruplexes are four‐stranded nucleic acid structures that are built from consecutively stacked guanine tetrad (G‐tetrad) assemblies. The simultaneous incorporation of two guanine base lesions, xanthine (X) and 8‐oxoguanine (O), within a single G‐tetrad of a G‐quadruplex was recently shown to lead to the formation of a stable G⋅G⋅X⋅O tetrad. Herein, a judicious introduction of X and O into a human telomeric G‐quadruplex‐forming sequence is shown to reverse the hydrogen‐bond polarity of the modified G‐tetrad while preserving the original folding topology. The control exerted over G‐tetrad polarity by joint X⋅O modification will be valuable for the design and programming of G‐quadruplex structures and their properties.
Specificity of the Metalloregulator CueR for Monovalent Metal Ions: Possible Functional Role of a Coordinated Thiol?
Authors: Szunyogh Dániel , Szokolai Hajnalka , Thulstrup Peter W. , Larsen Flemming H. , Gyurcsik Béla , Christensen Niels Johan , Stachura Monika , Hemmingsen Lars , Jancsó Attila
Published: November 2015

Metal‐ion‐responsive transcriptional regulators within the MerR family effectively discriminate between mono‐ and divalent metal ions. Herein we address the origin of the specificity of the CueR protein for monovalent metal ions. Several spectroscopic techniques were employed to study AgI, ZnII, and HgII binding to model systems encompassing the metal‐ion‐binding loop of CueR from E. coli and V. cholerae. In the presence of AgI, a conserved cysteine residue displays a pKa value for deprotonation of the thiol that is close to the physiological pH value. This property is only observed with the monovalent metal ion. Quantum chemically optimized structures of the CueR metal site with Cys 112 protonated demonstrate that the conserved Ser 77 backbone carbonyl oxygen atom from the other monomer of the homodimer is “pulled” towards the metal site. A common allosteric mechanism of the metalloregulatory members of the MerR family is proposed. For CueR, the mechanism relies on the protonation of Cys 112.
ZrO2‐Based Alternatives to Conventional Propane Dehydrogenation Catalysts: Active Sites, Design, and Performance
Authors: Otroshchenko Tatyana , Sokolov Sergey , Stoyanova Mariana , Kondratenko Vita A. , Rodemerck Uwe , Linke David , Kondratenko Evgenii V.
Published: November 2015

Non‐oxidative dehydrogenation of propane to propene is an established large‐scale process that, however, faces challenges, particularly in catalyst development; these are the toxicity of chromium compounds, high cost of platinum, and catalyst durability. Herein, we describe the design of unconventional catalysts based on bulk materials with a certain defect structure, for example, ZrO2 promoted with other metal oxides. Comprehensive characterization supports the hypothesis that coordinatively unsaturated Zr cations are the active sites for propane dehydrogenation. Their concentration can be adjusted by varying the kind of ZrO2 promoter and/or supporting tiny amounts of hydrogenation‐active metal. Accordingly designed Cu(0.05 wt %)/ZrO2‐La2O3 showed industrially relevant activity and durability over ca. 240 h on stream in a series of 60 dehydrogenation and oxidative regeneration cycles between 550 and 625 °C.
Corrosion‐Mediated Self‐Assembly (CMSA): Direct Writing Towards Sculpturing of 3D Tunable Functional Nanostructures
Authors: Wang Jing , Ho Ghim Wei
Published: November 2015

Inexpensive and readily available metal foils have been extracted and sculptured into nanocomposites without the expense of applied energy. The unwanted corrosion phenomenon has been contrarily utilized to realize desirable 3D nanostructures through a corrosion‐mediated self‐assembly (CMSA) method, which is unattainable by conventional 2D patterning routes. By virtue of electrochemical dissolution/re‐deposition initiated by brass corrosion, ionic derivatives (Zn2+ and Cu2+) are continuously supplied and seized by etchant ions (PO43−) to self‐assemble into well‐defined nanocomposites. Beyond 3D geometry patterning, CMSA enables arbitrarily tailoring of structures and chemical compositions with in situ multiphase amalgamation of hybrid materials, which improves homogeneity and thus mitigates phase separation issues. Importantly, the CMSA technique is demonstrated on transition metals for functional photocatalytic applications.
The use of variotherm systems for microinjection molding
Authors: Su Quanliang , Zhang Nan , Gilchrist Michael D.
Published: November 2015

Microinjection molding (μIM) is a fast‐developing technology which is used to produce polymeric microcomponents or components with micro/nanoscale features, such as are used in many fields including microfluidic diagnostics, microneedle drug delivery devices, microgears, and microswitches. The capabilities and performance of the microinjection molding process can be improved by incorporating a variotherm system. This leads to improved component quality, especially for high aspect ratio features. It can also help to increase the polymer flow path, improve feature replication, reduce residual stresses and molecular orientations, and also can eliminate weld lines. This article reviews the use of different variotherm systems in μIM, and describes how simulation of its use can provide insight when designing a mold cavity or a component with challenging microfeatures. The article highlights important problems, challenges and areas for further research. An increased understanding of these issues will provide opportunities to enhance further developments in the μIM process. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42962.
Growth of silver nanowires on carbon fiber to produce hybrid/waterborne polyurethane composites with improved electrical properties
Authors: An Xiaoyun , Ma Jingjing , Wang Kai , Zhan Maosheng
Published: November 2015

One dimensional silver nanowires (AgNWs) were grown on carbon fiber (CF) by a facile polyol method. Fourier transform infrared spectrometer (FTIR), laser Raman spectrometer (Raman), field‐emission scanning electron microscopy (FESEM), X ray diffraction instrument (XRD), energy dispersive spectrometer (EDS), and X‐ray photoelectron spectrometer (XPS) were carried out to reveal the structure, morphology, and formation mechanism of the CF‐AgNWs. It was found that AgNO3 concentration of 1.5 mM, reaction temperature of 160°C, and reaction time of 120 min were appropriate conditions for growth of AgNWs on CF. Moreover, a mechanism was suggested that the cysteamine on CF acted as nucleation centers for growth of silver nanoparticles and then small sized silver nanoparticles reduced from silver nitrate were grown on CF via the silver bonding to sulfur. Through an Ostwald ripening process, small sized silver nanoparticles were grown into larger particles. With the assistance of polyvinylpyrolidone (PVP), these larger particles were directed to grow in a definite direction to form nanowires. It was found that the resistance of CF‐AgNWs was decreased to 19.5 Ω, compared with that of CF (102.6 Ω) with the same quality. Thus, the CF‐AgNWs was added into waterborne polyurethane (WPU) to improve the electrical and dielectric properties of WPU. Results showed the WPU/CF‐AgNWs composite presented a lower percolation threshold than WPU/CF composite. When the content was 2.5 wt %, the volume resistivity of the WPU/CF‐AgNWs (1.90 × 104 Ω cm−1) was lower by approximately three orders of magnitude than that of WPU/CF (4.19 × 107 Ω cm−1). When the content was 2.5 wt %, the dielectric constant and dielectric loss of the WPU/CF‐AgNWs were improved to 15.24 and 0.21, which were 34.5 and 40.8% higher than that of WPU/CF. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43056.
Antimicrobial functionalization of poly(ethylene terephthalate) fabrics with waterborne N‐halamine epoxides
Authors: Cerkez Idris , Kocer H. B. , Worley S. D. , Broughton R. M. , Huang T. S.
Published: November 2015

A water dispersible terpolymer of [2‐(methacryloyloxy)ethyl]trimethylammonium chloride, glycidyl methacrylate and hydantoinyl acrylamide was synthesized and coated on poly(ethylene terephthalate) fabrics through a pad‐dry‐cure procedure. The coatings were rendered biocidal upon exposure to dilute household bleach solution. The halogenated fabrics exhibited great antimicrobial functionality with about six logs inactivation of S. aureus and E. coli O157:H7 within only two min of contact time. Moreover, the coatings were found to be very stable against repeated washings and UVA light exposure. It was shown that [2‐(methacryloyloxy)ethyl]trimethylammonium monomer is very useful in preparing waterborne N‐halamines which can impart rechargeable, effective, and stable antimicrobial coatings to poly(ethylene terephthalate) fabrics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43088.
Dispersion polymerization of uniform cross‐linked polystyrene microspheres in butan‐1‐ol
Authors: Beal John H. L. , Xu Ying , Al‐Salim Najeh , Arnold W. Mike
Published: November 2015

Butan‐1‐ol can be used as the solvent in the synthesis of poly(styrene‐co‐divinylbenzene‐co‐acrylic acid) microspheres by dispersion polymerization of a mixture of styrene, divinylbenzene (DVB), and acrylic acid (AA). Varying the proportion of the crosslinker DVB affects the size distribution and particle morphology profoundly, with 0.5–1.0% w/w producing spherical particles, whereas 2.0% w/w DVB produces irregular, concave morphologies. Varying the amount of AA from 5–7% w/w increases the average diameter of the spherical particles, whereas 9% w/w AA results in ovoid particles with dimpled surface morphology. In an optimized synthesis using 1.0% w/w DVB and 5% AA, uniform polymer microspheres with an average diameter of 0.8 µm and a coefficient of variation (CV) of diameter of 8.2% are produced. The use of a medium‐polarity solvent, such as butan‐1‐ol, as the solvent for dispersion polymerization will facilitate the incorporation of non‐polar moieties, such as organically‐passivated quantum dots, into the polymer during synthesis. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43103.
Microporous Polymers from a Carbazole‐Based Triptycene Monomer: Synthesis and Their Applications for Gas Uptake
Authors: Zhai Tian‐Long , Tan Liangxiao , Luo Yi , Liu Jun‐Min , Tan Bien , Yang Xiang‐Liang , Xu Hui‐Bi , Zhang Chun
Published: November 2015

Two kinds of novel organic microporous polymers TCPs (TCP‐A and TCP‐B) were prepared by two cost‐effective synthetic strategies from the monomer of tricarbazolyltriptycene (TCT). Their structure and properties were characterized by FT‐IR, solid 13C NMR, powder XRD, SEM, TEM, and gas absorption measurements. TCP‐B displayed a high surface area (1469 m2 g−1) and excellent H2 storage (1.70 wt % at 1 bar/77 K) and CO2 uptake abilities (16.1 wt % at 1 bar/273 K), which makes it a promising material for potential application in gas storage.
Simulations of accretion disks in pseudo‐complex General Relativity
Authors: Hess P. O. , Algalán B. M. , Schönenbach T. , Greiner W.
Published: November 2015

After a summary on pseudo‐complex General Relativity (pc‐GR), circular orbits and stable orbits in general are discussed, including predictions compared to observations. Using a modified version of a model for accretions disks, presented by Page and Thorne in 1974, we apply the raytracing technique in order to simulate the appearance of an accretion disk as it should be observed in a detector. In pc‐GR we predict a dark ring near a very massive, rapidly rotating object. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A proposal of quantization in flat space‐time with a minimal length present
Authors: Hess P.O.
Published: November 2015

The 4‐dimensional space‐time is extended to pseudo‐complex coordinates. Proposing the standard quantization rules in this extended space, the ones for the 4‐dimensional sub‐space acquire, as one solution, the commutation relations with non‐commuting coordinates. This demonstrates that the algebraic extension keeps the simple structure of Quantum Mechanics, while it also introduces an effective quite involved structure in the 4‐dimensional sub‐space. The first steps to pseudo‐complex Quantum Mechanics in 1‐dimension are outlined, awaiting still the interpretation of some new emerging structures. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Early Universe evolution in presence of magnetic fields
Authors: Delgado Gaspar I. , Pérez Martínez A. , Piccinelli G. , Sussman R. A.
Published: November 2015

We analyse the evolution of a magnetised Universe in a stage between the leptonic era and the beginning of the radiationdominated epoch using an anisotropic BianchiI model. In our description the cosmic fluid is made of primordial radiation, neutrinos, magnetic field, non‐interacting already decoupled dark matter (WIMPS), baryons, electrons, and positrons. The interaction of the field with the electron‐positron gas is taken into account, resulting in anisotropic equations of state for these constituents. Numerical simulations reveal some differences between the behaviour of magnetised BianchiI Universes and that of first order perturbations on an FLRW background. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effect of a primordial magnetic field on the inflaton decay process in a warm inflation scenario
Authors: Bastero‐Gil M. , Piccinelli G. , Sanchez A.
Published: November 2015

Magnetic fields appear everywhere in the Universe. Their widespread presence at high redshifts and very large scales suggests that their origin could be primordial. In particular, their presence during the inflationary epoch can certainly not be ruled out. In the warm inflation scenario, the coupling of the inflaton to other bosonic and fermionic fields gives rise to dissipative effects that modify the inflationary dynamics. Since primordial magnetic fields could have an effect on both the effective inflationary potential and the inflaton decay process, their contribution must be considered together with the finite temperature corrections. We review here their effect on the inflationary potential and present preliminary results of their intervention in the dissipation process. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Stable emergent Universe – a creation without Big‐Bang
Authors: Guendelman E. , Herrera R. , Labrana P. , Nissimov E. , Pacheva S.
Published: November 2015

Based on an earlier introduced new class of generalized gravity‐matter models defined in terms of two independent nonRiemannian volume forms (alternative generally covariant integration measure densities) on the space‐time manifold, we derive an effective “Einstein‐frame” theory featuring the following remarkable properties: (i) We obtain effective potential for the cosmological scalar field possessing two infinitely large flat regions which allows for a unified description of both early Universe inflation as well as of present dark energy epoch; (ii) for a specific parameter range the model possesses a non‐singular stable “emergent Universe” solution which describes an initial phase of evolution that precedes the inflationary phase. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Status of the LHC experiments and Standard‐Model result highlights
Authors: Biino C.
Published: November 2015

In this overview presentation I report on selected Standard Model (SM) physics highlights obtained by the ATLAS and CMS experiments in the first three years of data taking (Run I) at the new Large Hadron Collider (LHC) at CERN. By far the most important and exciting result of LHC Run I has been the observation of a new boson with a mass of 125 GeV, consistent with the properties of the SM Higgs boson. The discovery of the Higgs boson has brought the last missing piece of the Standard Model but the talk has given also an overview of the main results on di‐boson production, heavy flavour physics (b‐quark rare decays and CP violation; top‐quark mass and properties) and QCD. Finally a brief discussion on LHC future program. LHC is just now restarting operation at higher energy. New data will certainly give more detailed informations on the Higgs boson and by the end of this decade LHC experiments will have collected ten times more proton‐proton (pp) collisions. The Standard Model processes have been holding up to scrutiny over several orders of magnitude in production cross section but we are just at the beginning of the TeV scale exploration. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Search for new physics at the LHC and prospects for new discoveries
Authors: Conti G.
Published: November 2015

The Large Hadron Collider (LHC) at CERN has allowed the ATLAS and CMS experiments to collect a large amount of proton‐proton collision data at 7 TeV and 8 TeV centre‐of‐mass energies. This dataset was used to discover a Higgs boson with Standard Model‐like properties at a mass of about 125 GeV. In parallel, an impressive number of searches for deviations from the Standard Model expectations have been carried out in various physics areas (BSM Higgs, Supersymmetry, and Exotics). Representative searches in all of these domains will be presented and their impact on theoretical models beyond the SM assessed. To date, there is no evidence in the LHC data of a signal for New Physics beyond the SM. However, a few legacy 2–3δ deviations remain from both experiments. After an 18‐month shutdown, the LHC is about to deliver collision data at an increased centre‐of‐mass energy of 13 TeV. The large increase in collision energy will provide much improved sensitivity for various searches, in particular for high mass particles. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Magnetic field decay in normal radio pulsars
Authors: Igoshev A.P. , Popov S.B.
Published: November 2015

We analyse the origin of the magnetic field decay in normal radio pulsars found by us in a recent study. This decay has a typical time scale ∼4×105 yr and operates in the range ∼105– few×105 yr. We demonstrate that this field evolution may be either due to the Ohmic decay related to the scattering from phonons, or due to the Hall cascade which reaches the Hall attractor. According to our analysis, the first possibility seems to be more reliable. So, we attribute the discovered field decay mainly to the Ohmic decay by phonons, which is saturated at the age of a few×105 yr when a neutron star cools down to the critical temperature below which the phonon scattering does not contribute much to the resistivity of the crust. Some role of the Hall effect and attractor is not excluded, and will be analysed in our further studies. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
4U 1746–37: An ultra‐low‐mass compact star candidate
Authors: Li Zhao‐Sheng
Published: November 2015

The Rossi X‐ray Timing Explorer observed three photospheric radius expansion bursts in 4U 1746‐37, all with low touchdown fluxes. We discuss the possibiity of a low‐mass neutron star in 4U 1746‐37 if the touchdown flux corresponds to its Eddington limit. 4U 1746‐37 is a dipping binary system which has a high inclination angle. Two geometric effects, the reflection of the far side accretion disc and the obscuration of the near side accretion disc have also been included. We apply a Monte‐Carlo simulation, with typical values of hydrogen mass fraction and color correction factor, to constrain the mass and radius of the neutron star in 4U 1746‐37. We found that the mass of 4U 1746‐37 is 0.41+0.70–0.30 M® at 99.7 % confidence which is an ultra‐low‐mass compact star candidate. It could be reproduced by a self‐bound compact star, i.e., quark star or quark‐cluster star, from an ccretion‐induced collapse process. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)