bluuebunny/crossref_metadata_2025 huggingface dataset:
A General and Mild Catalytic α‐Alkylation of Unactivated Esters Using Alcohols
Authors: Guo Le , Ma Xiaochen , Fang Huaquan , Jia Xiangqing , Huang Zheng
Published: February 2015

Catalytic α‐alkylation of esters with primary alcohols is a desirable process because it uses low‐toxicity agents and generates water as the by‐product. Reported herein is a NCP pincer/Ir catalyst which is highly efficient for α‐alkylation of a broad scope of unactivated esters under mild reaction conditions. For the first time, alcohols alkylate unactivated α‐substituted acyclic esters, lactones, and even methyl and ethyl acetates. This method can be applied to the synthesis of carboxylic acid derivatives with diverse structures and functional groups, some of which would be impossible to access by conventional enolate alkylations with alkyl halides.
Highly Efficient Synthesis of Monodisperse Poly(ethylene glycols) and Derivatives through Macrocyclization of Oligo(ethylene glycols)
Authors: Zhang Hua , Li Xuefei , Shi Qiuyan , Li Yu , Xia Guiquan , Chen Long , Yang Zhigang , Jiang Zhong‐Xing
Published: February 2015

A macrocyclic sulfate (MCS)‐based approach to monodisperse poly(ethylene glycols) (M‐PEGs) and their monofunctionalized derivatives has been developed. Macrocyclization of oligo(ethylene glycols) (OEGs) provides MCS (up to a 62‐membered macrocycle) as versatile precursors for a range of monofunctionalized M‐PEGs. Through iterative nucleophilic ring‐opening reactions of MCS without performing group protection and activation, a series of M‐PEGs, including the unprecedented 64‐mer (2850 Da), can be readily prepared. Synthetic simplicity coupled with versatility of this new strategy may pave the way for broader applications of M‐PEGs.
The Emerging Chemistry of Sodium Ion Batteries for Electrochemical Energy Storage
Authors: Kundu Dipan , Talaie Elahe , Duffort Victor , Nazar Linda F.
Published: February 2015

Energy storage technology has received significant attention for portable electronic devices, electric vehicle propulsion, bulk electricity storage at power stations, and load leveling of renewable sources, such as solar energy and wind power. Lithium ion batteries have dominated most of the first two applications. For the last two cases, however, moving beyond lithium batteries to the element that lies below—sodium—is a sensible step that offers sustainability and cost‐effectiveness. This requires an evaluation of the science underpinning these devices, including the discovery of new materials, their electrochemistry, and an increased understanding of ion mobility based on computational methods. The Review considers some of the current scientific issues underpinning sodium ion batteries.
A Perfect Match: Fullerene Guests in Star‐Shaped Oligophenylenevinylene Mesogens
Authors: Lehmann Matthias , Hügel Markus
Published: February 2015

Star‐shaped oligophenylenevinylene (OPV) mesogens are shape‐persistent and possess formally large void space. A mesogen with three styrene repeating units packs densely in a columnar helical arrangement. Attachment of one fullerene through a short spacer results in an exceptional increase of the mesophase stability. X‐ray scattering and modeling evidence a triple‐helical arrangement in which the fullerene perfectly fills the void space between the arms of the star mesogen.
Construction of a New Class of Tetracycline Lead Structures with Potent Antibacterial Activity through Biosynthetic Engineering
Authors: Lešnik Urška , Lukežič Tadeja , Podgoršek Ajda , Horvat Jaka , Polak Tomaž , Šala Martin , Jenko Branko , Harmrolfs Kirsten , Ocampo‐Sosa Alain , Martínez‐Martínez Luis , Herron Paul R. , Fujs Štefan , Kosec Gregor , Hunter Iain S. , Müller Rolf , Petković Hrvoje
Published: February 2015

Antimicrobial resistance and the shortage of novel antibiotics have led to an urgent need for new antibacterial drug leads. Several existing natural product scaffolds (including chelocardins) have not been developed because their suboptimal pharmacological properties could not be addressed at the time. It is demonstrated here that reviving such compounds through the application of biosynthetic engineering can deliver novel drug candidates. Through a rational approach, the carboxamido moiety of tetracyclines (an important structural feature for their bioactivity) was introduced into the chelocardins, which are atypical tetracyclines with an unknown mode of action. A broad‐spectrum antibiotic lead was generated with significantly improved activity, including against all Gram‐negative pathogens of the ESKAPE panel. Since the lead structure is also amenable to further chemical modification, it is a platform for further development through medicinal chemistry and genetic engineering.
Robust Chemical Preservation of Digital Information on DNA in Silica with Error‐Correcting Codes
Authors: Grass Robert N. , Heckel Reinhard , Puddu Michela , Paunescu Daniela , Stark Wendelin J.
Published: February 2015

Information, such as text printed on paper or images projected onto microfilm, can survive for over 500 years. However, the storage of digital information for time frames exceeding 50 years is challenging. Here we show that digital information can be stored on DNA and recovered without errors for considerably longer time frames. To allow for the perfect recovery of the information, we encapsulate the DNA in an inorganic matrix, and employ error‐correcting codes to correct storage‐related errors. Specifically, we translated 83 kB of information to 4991 DNA segments, each 158 nucleotides long, which were encapsulated in silica. Accelerated aging experiments were performed to measure DNA decay kinetics, which show that data can be archived on DNA for millennia under a wide range of conditions. The original information could be recovered error free, even after treating the DNA in silica at 70 °C for one week. This is thermally equivalent to storing information on DNA in central Europe for 2000 years.
Noncovalent Hydrogel Beads as Microcarriers for Cell Culture
Authors: Wieduwild Robert , Krishnan Swati , Chwalek Karolina , Boden Annett , Nowak Mirko , Drechsel David , Werner Carsten , Zhang Yixin
Published: February 2015

Hydrogel beads as microcarriers could have many applications in biotechnology. However, bead formation by noncovalent cross‐linking to achieve high cell compatibility by avoiding chemical reactions remains challenging because of rapid gelation rates and/or low stability. Here we report the preparation of homogeneous, tunable, and robust hydrogel beads from peptide–polyethylene glycol conjugates and oligosaccharides under mild, cell‐compatible conditions using a noncovalent crosslinking mechanism. Large proteins can be released from beads easily. Further noncovalent modification allows for bead labeling and functionalization with various compounds. High survival rates of embedded cells were achieved under standard cell culture conditions and after freezing the beads, demonstrating its suitability for encapsulating and conserving cells. Hydrogel beads as functional system have been realized by generating protein‐producing microcarriers with embedded eGFP‐secreting insect cells.
Applying the Retro‐Enantio Approach To Obtain a Peptide Capable of Overcoming the Blood–Brain Barrier
Authors: Prades Roger , Oller‐Salvia Benjamí , Schwarzmaier Susanne M. , Selva Javier , Moros María , Balbi Matilde , Grazú Valeria , de La Fuente Jesus M. , Egea Gustavo , Plesnila Nikolaus , Teixidó Meritxell , Giralt Ernest
Published: February 2015

The blood–brain barrier (BBB) is a formidable physical and enzymatic barrier that tightly controls the passage of molecules from the blood to the brain. In fact, less than 2 % of all potential neurotherapeutics are able to cross it. Here, by applying the retro‐enantio approach to a peptide that targets the transferrin receptor, a full protease‐resistant peptide with the capacity to act as a BBB shuttle was obtained and thus enabled the transport of a variety of cargos into the central nervous system.
Enantioselective Enzymes by Computational Design and In Silico Screening
Authors: Wijma Hein J. , Floor Robert J. , Bjelic Sinisa , Marrink Siewert J. , Baker David , Janssen Dick B.
Published: February 2015

Computational enzyme design holds great promise for providing new biocatalysts for synthetic chemistry. A strategy to design small mutant libraries of complementary enantioselective epoxide hydrolase variants for the production of highly enantioenriched (S,S)‐diols and (R,R)‐diols is developed. Key features of this strategy (CASCO, catalytic selectivity by computational design) are the design of mutations that favor binding of the substrate in a predefined orientation, the introduction of steric hindrance to prevent unwanted substrate binding modes, and ranking of designs by high‐throughput molecular dynamics simulations. Using this strategy we obtained highly stereoselective mutants of limonene epoxide hydrolase after experimental screening of only 37 variants. The results indicate that computational methods can replace a substantial amount of laboratory work when developing enantioselective enzymes.
Metal Redox Processes for the Controlled Synthesis of Metal Alloy Nanoparticles
Authors: Kirkeminde Alec , Spurlin Stan , Draxler‐Sixta Laura , Cooper Jamie , Ren Shenqiang
Published: February 2015

Nanocrystalline metals have received widespread interest and found various applications owing to their magnetic and catalytic properties and in energy‐related fields. A flexible approach for the growth of nanoalloys with controlled properties and well‐defined structures on the atomic scale is thus greatly desired. A new synthetic method that avoids incompatible reduction potentials and rates would be critical to grow metal nanostructures with high purities and the desired stoichiometries. A metal‐redox strategy that employs spontaneous oxidation/reduction reactions to grow nanocrystalline alloys using molecular‐scale zerovalent metal precursors is now described. The selection of suitable zerovalent metal species allows for thermodynamic control of the compositional stoichiometry during the temperature‐dependent formation of the metal alloy nanoparticles. A practical and scalable strategy for nanoalloy growth that can potentially produce key metal components of superior metallurgical quality for catalytic and magnetic systems has thus been developed.
Discrete Magnesium Hydride Aggregates: A Cationic Mg13H18 Cluster Stabilized by NNNN‐Type Macrocycles
Authors: Martin Daniel , Beckerle Klaus , Schnitzler Silvia , Spaniol Thomas P. , Maron Laurent , Okuda Jun
Published: February 2015

Large magnesium hydride aggregates [Mg13(Me3TACD)6(μ2‐H12)(μ3‐H6)][A]2 ((Me3TACD)H=1,4,7‐trimethyl‐1,4,7,10‐tetraazacyclododecane; A=AlEt4, AlnBu4, B{3,5‐(CF3)2C6H3}4) were synthesized stepwise from alkyl complexes [Mg2(Me3TACD)R3] (R=Et, nBu) and phenylsilane in the presence of additional MgII ions. The central magnesium atom is octahedrally coordinated by six hydrides as in solid α‐MgH2 of the rutile type. Further coordination to six magnesium atoms leads to a substructure of seven edge‐sharing octahedra as found in the hexagonal layer of brucite (Mg(OH)2). Upon protonolysis in the presence of 1,2‐dimethoxyethane (DME), this cluster was degraded into a tetranuclear dication [Mg2(Me3TACD)(μ‐H)2(DME)]2[A]2.
Nickel‐Catalyzed Enantioselective CC Bond Formation through CO Cleavage in Aryl Esters
Authors: Cornella Josep , Jackson Evan P. , Martin Ruben
Published: February 2015

We report the first enantioselective CC bond formation through CO bond cleavage using aryl ester counterparts. This method is characterized by its wide substrate scope and results in the formation of quaternary stereogenic centers with high yields and asymmetric induction.
Trametes versicolor laccase immobilized poly(glycidyl methacrylate) based cryogels for phenol degradation from aqueous media
Authors: Doğan Tuğba , Bayram Engin , Uzun Lokman , Şenel Serap , Denizli Adil
Published: February 2015

This study aims removal of phenols in wastewater by enzymatic oxidation method. In this study, Trametes versicolor laccase was covalently immobilized onto a cryogel matrix by the nucleophilic attack of amino groups of laccase to epoxy groups of matrix. Glycidyl methacrylate was chosen as functional monomer to prepare poly(2‐hydroxyethyl methacrylate‐co‐glycidyl methacrylate) [p(HEMA‐co‐GMA)] cryogels. The enzyme immobilized matrix was characterized by FTIR, SEM, and swelling tests. The effect of pH, reaction time, temperature, substrate concentration, enzyme concentration, and storage period on immobilized enzyme activity was determined and compared with those of free enzyme. The model substrate was 2,2′‐azino‐bis(3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS). Lineweaver‐Burk plots were used to calculate Km and Vm values. Km values were 165.1 and 156.0 µM while Vm values were 55.2 µM min−1 and 1.57 µM min−1 for free and immobilized laccase, respectively. Immobilized enzyme was determined to retain 82.5% and 72.0% of the original activity, respectively, after 6 consecutive use and storage period of 4 weeks. The free enzyme retained only 24.0% of its original activity following the same storage period. Lastly, decomposition products resulting from enzymatic oxidation of a model phenolic compound (3,5‐dinitrosalicylic acid) in aqueous solution were identified by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41981.
Investigation of adsorption behaviors of Cu(II), Pb(II), and Cd(II) from water onto the high molecular weight poly (arylene ether sulfone) with pendant carboxyl groups
Authors: Wu Xinghua , Wang Dazhi , Zhang Shaoyin , Cai Weijie , Yin Yuxin
Published: February 2015

Three types of high molecular weight polyarylether adsorbents with different molar ratios of carboxyl and phenylene were designed and synthesized through direct polycondensation in mixture solvents. The as‐prepared polymers were characterized by FTIR, 1H‐NMR, TGA, DSC, SEM, EDS, and GPC in order to study the regularity of polymeric adsorption/thermostability performances. Because of the highest molar ratio of carboxyl and phenylene, PAES‐C‐Na presented the highest adsorption capacity of Cu2+ compared to PAESK‐C‐Na and PAES; therefore, PAES‐C‐Na was opted to study the impacts of adsorbent dosage, pH, contact time, and initial concentration on the adsorption of Pb2+ and Cd2+. Moreover, a kinetic analysis revealed that the adsorption process followed pseudo‐second‐order model, while the thermodynamic experimental data properly fitted with the Freundlich model. The multi‐component competitive adsorption capacity followed the order Pb2+ > Cu2+ > Cd2+. Additionally, the regeneration tests indicated that PAES‐C‐Na still possessed the excellent adsorption capacity after several recycles. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41984.
Comparative Response of Rat and Rabbit Conceptuses In Vitro to Inhibitors of Histiotrophic Nutrition
Authors: Marshall Valerie A. , Johnson Kamin J. , Moore Nigel P. , Rasoulpour Reza J. , Tornesi Belen , Carney Edward W.
Published: February 2015

Histiotrophic nutrition via the visceral yolk sac is an essential nutritional pathway of the rodent conceptus, and inhibition of this pathway may cause growth retardation, malformations, and death in rodent embryos. Morphologic differences among species during early development indicate that the visceral yolk sac histiotrophic nutrition pathway may be of lesser importance in nonrodent species, including humans. Here, comparative studies were conducted with inhibitors of different steps in the visceral yolk sac histiotrophic nutrition pathway to determine whether the rabbit is similarly responsive to the rat. Early somite stage New Zealand White rabbit and Crl:CD(SD) rat conceptuses (gestation day 9, rabbits; gestation day 10, rats) were exposed for 48 hr to three different histiotrophic nutrition pathway inhibitors using whole embryo culture techniques, after which they were evaluated for growth and malformations. Cubilin antibody, an inhibitor of endocytosis, reduced growth and development and increased malformations in both rat and rabbit embryos, although the rabbit appeared more sensitive. Leupeptin, a lysosomal cysteine protease inhibitor, also impaired growth and development and increased malformations in rat embryos, while in the rabbit it induced malformations and a slight decrease in morphology score but had no effect upon growth. Trypan blue, an inhibitor of endocytosis and endosome maturation, affected all measures in both species to a similar degree at the highest concentration (2500 μg/ml), but rat embryos responded to a greater extent at lower concentrations. Although the specific adverse outcomes appear to be different, these results demonstrate that rabbits, like rats, are sensitive to inhibitors of the histiotrophic nutrition pathway
Ertüchtigung der Nibelungenbrücke Worms
Authors: Pelke Eberhard , Zichner Tilman
Published: February 2015

Die Ertüchtigung der Nibelungenbrücke im Verlauf der B47 über den Rhein bei Worms war eine sehr komplexe Maßnahme, da die Vorlandbrücken, deren Entstehung in den letzten Jahren des 19. Jahrhunderts lag, mit einer Strombrücke, die eine der ersten im Freivorbau errichtete Spannbetonbrücke ist, verknüpft sind. Ihre Konzeption musste sich nach den noch vorhandenen und aus wirtschaftlichen Gründen weiter zu verwendenden Fundamenten der im 2. Weltkrieg zerstörten Brücke aus Stahlfachwerkbögen richten. Zudem gab es weder eine gültige Spannbetonnorm noch Richtzeichnungen für die konstruktive Durchbildung.

Dieser Bericht konzentriert sich auf die eher ungewöhnlichen Baumaßnahmen zur Ertüchtigung von Strombrücke und Vorlandbrücken. Auf die “üblichen” Instandsetzungsarbeiten, wie z. B. Betonersatz, Bau eines neuen Treppenturmes oder Erneuerung von Entwässerung, Abdichtung und Belag, wird nicht eingegangen.

The Improvement of the Nibelungen Bridge at Worms

The improvement of the Nibelungen Bridge crossing the river Rhine at Worms as part of the B 47 has been a very complex task due to the fact that the foreshore bridges built in the last years of the 19th century were linked to a river bridge, which is one of the first prestressed concrete bridges constructed using the cantilever method.

Its conceptual design had to comply with the still existing and for economic reasons to be reused foundations of a steel framework bridge destroyed during the Second World War. Moreover, both a valid standard for prestressed concrete constructions and guidance drawings were lacking.

This article concentrates on the rather extraordinary approach to improve the river bridge and the foreshore bridges. It will not enlarge on conventional rehabilitation work as e.g. concrete replacement, construction of a new stair tower or renewal of drainage, sealing and covering.
Endverankerungen bei Ertüchtigung von Brücken mit externer Vorspannung
Authors: Novák Balthasar , Pelke Eberhard , Boros Vazul , Reinhard Jochen , Berger Dieter
Published: February 2015

Die Instandsetzung von bestehenden Massivbrücken durch externe Vorspannung kann eine effiziente Maßnahme der Tragwerksertüchtigung darstellen. Durch den Einbau von zusätzlichen externen Spanngliedern ist es möglich, Defizite in der Tragfähigkeit, Gebrauchstauglichkeit und Dauerhaftigkeit von Bauwerken zu kompensieren und dadurch eine Verlängerung der Nutzungsdauer zu erreichen. Im Rahmen einer wissenschaftlichen Abhandlung erfolgte eine systematische Analyse dieser Art von Verstärkungsmaßnahmen, um vorhandene und bisher nicht bekannte Defizite ausgeführter Ertüchtigungen im Speziellen bei den Endverankerungssystemen aufzuzeigen. Auf Basis der Erkenntnisse der Untersuchungen wurden Varianten für die Verankerung der hohen Kräfte aus externer Vorspannung erarbeitet und bereits angewandte Konzepte diskutiert und Verbesserungspotenziale aufgezeigt. Weiter wurden verschiedene Planungshilfen erstellt, um den Planungsablauf zu vereinheitlichen und zu erleichtern.

Anchorages of external tendons for strengthening reinforced concrete bridges

Additional prestressing of existing reinforced concrete bridges using external tendons represents an efficient method of structural retrofitting. The installation of external tendons leads to a reduction of deficiencies in safety, serviceability and durability, thus increasing the expected lifespan of the bridge. A scientific research project was initiated to analyze potential vulnerabilities of such measures – especially at the anchorage devices‐ , considering the insights from several recently retrofitted bridges. Based on the results from this study new concepts for the anchorage of the significant external prestressing forces into the existing superstructure are introduced. Common solutions of this detail are examined and improvements are proposed. Furthermore several tools have been developed to facilitate and standardize the planning process.
Seismische Isolierung des Gebetssaals der Großen Moschee von Algerien
Authors: Akkermann Jan , Hewener Alexander
Published: February 2015

In Algier entsteht derzeit die drittgrößte Moschee der Welt, deren Gebetssaal für den Besuch von bis zu 32 000 Gläubigen ausgelegt wurde. Der Architekturidee von einer hohen Transparenz des Innenraums folgend wurde ein spezielles, dreidimensionales Aussteifungssystem ohne innenseitige Aussteifungselemente entworfen. Nordalgerien liegt in einer seismisch hochaktiven Zone. Zur Gewährleistung der Standsicherheit des monumentalen Bauwerks wurde eine seismische Isolierung mittels Gleitpendel‐Isolatoren gewählt. Ferner werden viskose Hydraulikdämpfer zur Reduzierung der Erdbebenverformung verwendet. Der Artikel beschreibt Erdbebenentwurf und ‐bemessung des Gebäudes und stellt die normativen Besonderheiten bei der Planung, der Ausschreibung und der Ausführung der Konstruktion gemäß Euronormen (EN) vor.

Seismic Isolation of the Prayer Hall of the Great Mosque of Algiers

The world's third largest mosque, whose prayer hall is designed for up to 32 000 believers, is presently under construction. Following the architectural idea of a high transparency inside the hall, a special three‐dimensional stiffening system without inner shear walls or bracings was designed. Northern Algeria is a strong motion area. To assure the structural safety of the monumental building a seismic isolation with sliding‐ isolation‐pendulum was chosen. Furthermore fluid viscous dampers were arranged to reduce the earthquake displacements. The article describes the earthquake design and the related calculations and presents the specialties in the design codes concerning the planning, the tender documents and the execution of the constructions according to European codes (EN).
Focused information criterion on predictive models in personalized medicine
Authors: Yang Hui , Liu Yutao , Liang Hua
Published: February 2015

Instead of assessing the overall fit of candidate models like the traditional model selection criteria, the focused information criterion focuses attention directly on the parameter of the primary interest and aims to select the model with the minimum estimated mean squared error for the estimate of the focused parameter. In this article we apply the focused information criterion for personalized medicine. By using individual‐level information from clinical observations, demographics, and genetics, we obtain the personalized predictive models to make the prognosis and diagnosis individually. The consideration of the heterogeneity among the individuals helps reduce the prediction uncertainty and improve the prediction accuracy. Two real data examples from biomedical research are studied as illustrations.
Pomegranate juice polyphenols induce a phenotypic switch in macrophage polarization favoring a M2 anti‐inflammatory state
Authors: Aharoni Saar , Lati Yoni , Aviram Michael , Fuhrman Bianca
Published: February 2015

It was documented that pomegranate has anti‐inflammatory effects. In this study, we investigated a direct effect of pomegranate juice (PJ) and its polyphenols on macrophage inflammatory phenotype. In vitro, PJ and its major polyphenols dose‐dependently attenuated macrophage response to M1 proinflammatory activation in J774.A1 macrophage‐like cell line. This was evidenced by a significant decrease in TNFα and IL‐6 secretion in response to stimulation by IFNγ and Lipopolysaccharide. In addition, PJ and punicalagin dose‐dependently promoted the macrophages toward a M2 anti‐inflammatory phenotype, as determined by a significant increase in the spontaneous secretion of IL‐10. In mice, supplementation with dietary PJ substantially inhibited the M2 to M1macrophage phenotypic shift associated with age, toward a favorable anti‐inflammatory M2 phenotype. This effect was also reflected in the mice atherosclerotic plaques, as evaluated by the distinct expression of arginase isoforms. PJ consumption inhibited the increment of arginase II (Arg II, M1) mRNA expression during aging, and maintained the levels of Arg I (M2) expression similar to those in young mice aorta. This study demonstrates, for the first time, that pomegranate polyphenols directly suppress macrophage inflammatory responses and promote M1 to M2 switch in macrophage phenotype. Furthermore, this study indicates that PJ consumption may inhibit the progressive proinflammatory state in the aorta along atherosclerosis development with aging, due to a switch in macrophage phenotype from proinflammatory M1to anti‐inflammatory M2. © 2015 BioFactors, 41(1):44–51, 2015
Xylan catabolism is improved by blending bioprospecting and metabolic pathway engineering in Saccharomyces cerevisiae
Authors: Lee Sun‐Mi , Jellison Taylor , Alper Hal S.
Published: February 2015

Complete utilization of all available carbon sources in lignocellulosic biomass still remains a challenge in engineering Saccharomyces cerevisiae. Even with efficient heterologous xylose catabolic pathways, S. cerevisiae is unable to utilize xylose in lignocellulosic biomass unless xylan is depolymerized to xylose. Here we demonstrate that a blended bioprospecting approach along with pathway engineering and evolutionary engineering can be used to improve xylan catabolism in S. cerevisiae. Specifically, we perform whole genome sequencing‐based bioprospecting of a strain with remarkable pentose catabolic potential that we isolated and named Ustilago bevomyces. The heterologous expression of xylan catabolic genes enabled S. cerevisiae to grow on xylan as a single carbon source in minimal medium. A combination of bioprospecting and metabolic pathway evolution demonstrated that the xylan catabolic pathway could be further improved. Ultimately, engineering efforts were able to achieve xylan conversion into ethanol of up to 0.22 g/L on minimal medium compositions with xylan. This pathway provides a novel starting point for improving lignocellulosic conversion by yeast.
Optimized Sleeping Beauty transposons rapidly generate stable transgenic cell lines
Authors: Kowarz Eric , Löscher Denise , Marschalek Rolf
Published: February 2015

Stable gene expression in mammalian cells is a prerequisite for many in vitro and in vivo experiments. However, either the integration of plasmids into mammalian genomes or the use of retro‐/lentiviral systems have intrinsic limitations. The use of transposable elements, e.g. the Sleeping Beauty system (SB), circumvents most of these drawbacks (integration sites, size limitations) and allows the quick generation of stable cell lines. The integration process of SB is catalyzed by a transposase and the handling of this gene transfer system is easy, fast and safe. Here, we report our improvements made to the existing SB vector system and present two new vector types for robust constitutive or inducible expression of any gene of interest. Both types are available in 16 variants with different selection marker (puromycin, hygromycin, blasticidin, neomycin) and fluorescent protein expression (GFP, RFP, BFP) to fit most experimental requirements. With this system it is possible to generate cell lines from stable transfected cells quickly and reliably in a medium‐throughput setting (three to five days). Cell lines robustly express any gene‐of‐interest, either constitutively or tightly regulated by doxycycline. This allows many laboratory experiments to speed up generation of data in a rapid and robust manner.
Influenza A M2 protein conformation depends on choice of model membrane
Authors: Saotome Kei , Duong‐Ly Krisna C. , Howard Kathleen P.
Published: February 2015

While crystal and NMR structures exist of the influenza A M2 protein, there is disagreement between models. Depending on the requirements of the technique employed, M2 has been studied in a range of membrane mimetics including detergent micelles and membrane bilayers differing in lipid composition. The use of different model membranes complicates the integration of results from published studies necessary for an overall understanding of the M2 protein. Here we show using site‐directed spin‐label EPR spectroscopy (SDSL‐EPR) that the conformations of M2 peptides in membrane bilayers are clearly influenced by the lipid composition of the bilayers. Altering the bilayer thickness or the lateral pressure profile within the bilayer membrane changes the M2 conformation observed. The multiple M2 peptide conformations observed here, and in other published studies, optimistically may be considered conformations that are sampled by the protein at various stages during influenza infectivity. However, care should be taken that the heterogeneity observed in published structures is not simply an artifact of the choice of the model membrane. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 405–411, 2015.
Substantiating Byzantium: The role of artifacts in the co‐construction of narratives
Authors: Chronis Athinodoros
Published: February 2015

Acknowledging the abundance of narrative elements in servicescapes and anchored on the premise that consumption experiences are co‐constructed, this research extends existing servicescapes scholarship by theorizing the role of material objects in the co‐construction of narratives at storyscapes, that is, those servicescapes where narratives are at the center stage of the consumption experience. Using a museum exhibition of Byzantine heritage in Thessaloniki, Greece, the findings provide insight on the way in which consumers engage and “read” material artifacts in narrative co‐construction. The emergent framework theorizes consumer participation as narrative substantiation and sheds light on its four constitutive narrative‐construction processes (completing, relating, recontextualizing, and imagining) and on the ways in which consumers anchor these processes on artifact's materiality (artifactual knowledge, practicalness, intermateriality, and realness). Furthermore, this research offers an alternative approach to the existing language analogy according to which objects have their own voice and rhetoric. I see objects, instead, as contributing an evocative engagement according to which consumers unpack objects not only in their reference to the servicescape narrative but also in reference to their own personal and collective lives. Copyright © 2015 John Wiley & Sons, Ltd.
A difficult diagnosis of Hodgkin lymphoma due to immune thrombocytopenia
Authors: Marino Silvia , Di Cataldo Andrea , Magro Gaetano , D'Amico Salvatore , La Spina Milena , Di Benedetto Vincenzo , Meli Mariaclaudia , Moscheo Carla , Russo Giovanna
Published: February 2015

Key Clinical Message

We report a rare clinical presentation of childhood Hodgkin lymphoma with immune thrombocytopenia. Diagnostic biopsy of the abdominal mass was performed after administration of intravenous immunoglobulins, steroids, and platelet transfusion. Concomitant thrombocytopenia complicated the whole diagnosis work up and the initial management of neoplasia.
Moyamoya disease and pregnancy: case reports and criteria for successful vaginal delivery
Authors: Sei Kiguna , Sasa Hidenori , Furuya Kenichi
Published: February 2015

Key Clinical Message

Based on our experience with seven deliveries (five cesarean and two vaginal deliveries) in five women with Moyamoya disease, we discussed the appropriate method of delivery and anesthesia for patients with Moyamoya disease. In certain conditions, women with Moyamoya disease can successfully undergo vaginal delivery.
Does Fluorine Participate in Halogen Bonding?
Authors: Eskandari Kiamars , Lesani Mina
Published: February 2015

When R is sufficiently electron withdrawing, the fluorine in the RF molecules could interact with electron donors (e.g., ammonia) and form a noncovalent bond (F⋅⋅⋅N). Although these interactions are usually categorized as halogen bonding, our studies show that there are fundamental differences between these interactions and halogen bonds. Although the anisotropic distribution of electronic charge around a halogen is responsible for halogen bond formations, the electronic charge around the fluorine in these molecules is spherical. According to source function analysis, F is the sink of electron density at the F⋅⋅⋅N BCP, whereas other halogens are the source. In contrast to halogen bonds, the F⋅⋅⋅N interactions cannot be regarded as lump–hole interactions; there is no hole in the valence shell charge concentration (VSCC) of fluorine. Although the quadruple moment of Cl and Br is mainly responsible for the existence of σ‐holes, it is negligibly small in the fluorine. Here, the atomic dipole moment of F plays a stabilizing role in the formation of F⋅⋅⋅N bonds. Interacting quantum atoms (IQA) analysis indicates that the interaction between halogen and nitrogen in the halogen bonds is attractive, whereas it is repulsive in the F⋅⋅⋅N interactions. Virial‐based atomic energies show that the fluorine, in contrast to Cl and Br, stabilize upon complex formation. According to these differences, it seems that the F⋅⋅⋅N interactions should be referred to as “fluorine bond” instead of halogen bond.
Photoreversible Prodrugs and Protags: Switching the Release of Maleimides by Using Light under Physiological Conditions
Authors: Göstl Robert , Hecht Stefan
Published: February 2015

A water‐soluble furyl‐substituted diarylethene derivative has been prepared that can undergo reversible Diels–Alder reactions with maleimides to yield photoswitchable Diels–Alder adducts. Employing bioorthogonal visible light, the release of therapeutically effective concentrations of maleimide‐based reactive inhibitors or labels from these “prodrugs” or “protags” could be photoreversibly triggered in buffered, aqueous solution at body temperature. It is shown how the release properties can be fine‐tuned and a thorough investigation of the release dynamics is presented. Our system should allow for spatiotemporal control over the inhibition and labeling of specific protein targets and is ready to be surveyed in living organisms.
Total and Semi‐Syntheses of Antimicrobial Thuggacin Derivatives
Authors: Franke Jana , Bock Martin , Dehn Richard , Fohrer Jörg , Mhaske Santosh B. , Migliorini Antonella , Kanakis Argyrios A. , Jansen Rolf , Herrmann Jennifer , Müller Rolf , Kirschning Andreas
Published: February 2015

The total and semi‐synthesis of 13 new macrolactones derived from thuggacin, which is a secondary metabolite from the myxobacterium Sorangium cellulosum, are reported. The thuggacins have attracted much attention due to their strong antibacterial activity, particularly towards Mycobacterium tuberculosis. This study focuses on 1) thuggacin derivatives that cannot equilibrate by transacylation between the three natural thuggacins A–C, 2) the roles of the thiazole ring, and 3) the hexyl side chain at C2. Semi‐synthetic O‐methylation at C17 suppressed the transacylations without a substantial loss of antibacterial activity. Exchanging the C17–C25 side chain for simplified hydrophobic chains led to complete loss of antibacterial activity. Exchange of the thiazole by an oxazole ring or removal of the hexyl side chain at C2 had no substantial effect on the biological properties.
Construction of a Selective Fluorescent Probe for GSH Based on a Chloro‐Functionalized Coumarin‐enone Dye Platform
Authors: Liu Yawei , Lv Xin , Liu Jing , Sun Yuan‐Qiang , Guo Wei
Published: February 2015

Glutathione (GSH), the most abundant intracellular biothiol, protects cellular components from damage caused by free radicals and reactive oxygen species (ROS), and plays a crucial role in human pathologies. A fluorescent probe that can selectively sense intracellular GSH would be very valuable for understanding of its biological functions and mechanisms of diseases. In this work, a 3,4‐dimethoxythiophenol‐substituted coumarin‐enone was exploited as a reaction‐type fluorescent probe for GSH based on a chloro‐functionalized coumarin‐enone platform. In the probe, the 3,4‐dimethoxythiophenol group functions not only as a fluorescence quencher through photoinduced electron transfer (PET) to ensure a low background fluorescence, but also as a reactive site for biothiols. The probe displays a dramatic fluorescence turn‐on response toward GSH with the long‐wavelength emission (600 nm) and significant Stokes shift (100 nm). The selectivity of the probe toward GSH over cysteine (Cys), homocysteine (Hcy), and other amino acids was demonstrated. Assisted by laser‐scanning confocal microscopy, we have demonstrated that the probe could specifically sense GSH over Cys/Hcy in human renal cell carcinoma SiHa cells.
How a Redox‐Innocent Metal Promotes the Formal Reductive Elimination of Biphenyl Using Redox‐Active Ligands
Authors: Ashley Daniel Charles , Baik Mu‐Hyun
Published: February 2015

One of the most compelling strategies for utilizing redox‐active ligands is to perform redox events at the ligands to avoid accessing prohibitively high energy oxidation states at the metal center. This has been demonstrated experimentally in many systems, yet there is little understanding of the fundamental electronic structures involved with these transformations or how to control them. Here, the reductive elimination of biphenyl from [M(isq)2Ph2] (M=Ti, Zr, and Hf and isq=2,4‐di‐tert‐butyl‐6‐tert‐butyliminosemiquinone) was studied computationally. It was found that the metal remains in the +IV oxidation state and all redox chemistry was mediated by the redox‐active ligands. Two types of electron‐transfer mechanisms were identified, an asymmetric unpaired electron transfer (UET) and a symmetric pairwise electron transfer (PET), the former always being lower in energy. The energetic differences between these two mechanisms were explained through simple molecular orbital theory arguments. Despite the metal’s redox‐inactivity, it still has a marked influence on the calculated energetics of the reaction, with the Ti systems being much more reactive than the Zr/Hf systems. This primarily originates from the shorter TiPh bond, which leads to a stronger filled‐filled interaction between these ligands at the reactant state. This greater reactant destabilization leads to the lower activation energies.
Two Heterometallic–Organic Frameworks Composed of Iron(III)‐Salen‐Based Ligands and d10 Metals: Gas Sorption and Visible‐Light Photocatalytic Degradation of 2‐Chlorophenol
Authors: Li Jing , Yang Jin , Liu Ying‐Ying , Ma Jian‐Fang
Published: February 2015

Two examples of heterometallic–organic frameworks (HMOFs) composed of dicarboxyl‐functionalized FeIII‐salen complexes and d10 metals (Zn, Cd), [Zn2(Fe‐L)2(μ2‐O)(H2O)2]⋅4 DMF⋅4 H2O (1) and [Cd2(Fe‐L)2(μ2‐O)(H2O)2]⋅2 DMF ⋅H2O (2) (H4L=1,2‐cyclohexanediamino‐N,N′‐bis(3‐methyl‐5‐carboxysalicylidene), have been synthesized and structurally characterized. In 1 and 2, each square‐pyramidal FeIII atom is embedded in the [N2O2] pocket of an L4− anion, and these units are further bridged by a μ2‐O anion to give an (Fe‐L)2(μ2‐O) dimer. The two carboxylate groups of each L4− anion bridge ZnII or CdII atoms to afford a 3D porous HMOF. The gas sorption and magnetic properties of 1 and 2 have been studied. Remarkably, 1 and 2 show activity for the photocatalytic degradation of 2‐chlorophenol (2‐CP) under visible‐light irradiation, which, to the best of our knowledge, is the first time that this has been observed for FeIII‐salen‐based HMOFs.
Gold(I)‐Catalyzed Intramolecular Cycloisomerization of Propargylic Esters with Furan Rings
Authors: Yang Jin‐Ming , Tang Xiang‐Ying , Shi Min
Published: February 2015

A gold‐catalyzed intramolecular cycloisomerization of α‐yne‐furans 1 is described in this contribution. A variety of cyclic α,β‐unsaturated aldehyde or ketone derivatives and nitrogen‐containing tricyclic adducts were obtained selectively in moderate to excellent yields under mild conditions by varying the substituents on the standard substrates.
Syngas and Synfuels from H2O and CO2: Current Status
Authors: Nguyen Van Nhu , Blum Ludger
Published: February 2015

Hydrogen and synthesis gas (syngas) production from water and carbon dioxide as well as fuel processing for fuel cells and for transport applications have great potential in addressing major challenges in the area of energy. This review highlights recent progress and future trends on energy storage via carbon‐neutral fuels made from water, carbon dioxide and renewable energies. The various electrochemical, thermochemical and photochemical energy conversion technologies for dissociation of H2O or/and CO2are reviewed and discussed systematically.
Dry Reforming and Reverse Water Gas Shift: Alternatives for Syngas Production?
Authors: Schwab Ekkehard , Milanov Andrian , Schunk Stephan Andreas , Behrens Axel , Schödel Nicole
Published: February 2015

Dry reforming and reverse water gas shift are often discussed as potential carbon dioxide sinks. They may in the near future act as enablers for improving carbon footprints of certain value chains. In this paper, it will be critically discussed in short format why both technologies can only be operated economically and sustainably in defined contexts. A number of technical and economic challenges of both reactions are discussed and potential solutions for technical realization are presented.
Labile and Recalcitrant Soil Carbon and Nitrogen Pools in Tidal Salt Marshes of the Eastern Chinese Coast as Affected by Short‐Term C4 Plant Spartina alterniflora Invasion
Authors: Yang Wen , An Shuqing , Zhao Hui , Fang Shubo , Xia Lu , Xiao Yan , Qiao Yajun , Cheng Xiaoli
Published: February 2015

Terrestrial ecosystems carbon (C) and nitrogen (N) cycles, affected by plant invasion, are not fully understood. In this study, the impact of 10 years Spartina alterniflora invasion on soil organic matter (SOM), labile, and recalcitrant pools was examined comparing with bare flat and native Suaeda salsa and Phragmites australis communities in tidal salt marshes of the Eastern Chinese coast. Short‐term S. alterniflora invasion significantly raised C and N concentrations in SOM, labile and recalcitrant pools compared to bare flat, S. salsa and P. australis soils. Spartina alterniflora soil had higher recalcitrant index for C relative to bare flat. The proportion of S. alterniflora‐derived C and the decomposition rate of old C in the labile pool were significantly higher than those in the recalcitrant pool. However, the S. alterniflora‐derived C stock of the recalcitrant pool was much greater than that of the labile pool. The SOM and recalcitrant pools in S. alterniflora soil had significantly higher δ15N levels compared with bare flat, indicating an increased N loss following S. alterniflora invasion. The results suggested that short‐term S. alterniflora invasion significantly enlarged soil organic C and N pools via altering SOM input and decomposition.
Supervillin binds the Rac/Rho‐GEF Trio and increases Trio‐mediated Rac1 activation
Authors: Son Kyonghee , Smith Tara C. , Luna Elizabeth J.
Published: February 2015

We investigated cross‐talk between the membrane‐associated, myosin II‐regulatory protein supervillin and the actin‐regulatory small GTPases Rac1, RhoA, and Cdc42. Supervillin knockdown reduced Rac1‐GTP loading, but not the GTP loading of RhoA or Cdc42, in HeLa cells with normal levels of the Rac1‐activating protein Trio. No reduction in Rac1‐GTP loading was observed when supervillin levels were reduced in Trio‐depleted cells. Conversely, overexpression of supervillin isoform 1 (SV1) or, especially, isoform 4 (SV4) increased Rac1 activation. Inhibition of the Trio‐mediated Rac1 guanine nucleotide exchange activity with ITX3 partially blocked the SV4‐mediated increase in Rac1‐GTP. Both SV4 and SV1 co‐localized with Trio at or near the plasma membrane in ruffles and cell surface projections. Two sequences within supervillin bound directly to Trio spectrin repeats 4–7: SV1–171, which contains N‐terminal residues found in both SV1 and SV4 and the SV4‐specific differentially spliced coding exons 3, 4, and 5 within SV4 (SV4‐E345; SV4 amino acids 276–669). In addition, SV4‐E345 interacted with the homologous sequence in rat kalirin (repeats 4–7, amino acids 531–1101). Overexpressed SV1–174 and SV4‐E345 affected Rac1‐GTP loading, but only in cells with endogenous levels of Trio. Trio residues 771–1057, which contain both supervillin‐interaction sites, exerted a dominant‐negative effect on cell spreading. Supervillin and Trio knockdowns, separately or together, inhibited cell spreading, suggesting that supervillin regulates the Rac1 guanine nucleotide exchange activity of Trio, and potentially also kalirin, during cell spreading and lamellipodia extension. © 2015 Wiley Periodicals, Inc.
Two major network domains in the dorsal raphe nucleus
Authors: Commons Kathryn G.
Published: February 2015

Serotonin neurons in the dorsal and median raphe nuclei (DR and MR) are clustered into heterogeneous groups that give rise to topographically organized forebrain projections. However, a compelling definition of the key subgroups of serotonin neurons within these areas has remained elusive. In order to be functionally distinct, neurons must participate in distinct networks. Therefore, we analyzed subregions of the DR and MR by their afferent input. Clustering methods and principal component analysis were applied in mouse to anterograde tract‐tracing experiments available from the Allen Mouse Brain Connectivity Atlas. The results revealed a major break in the networks of the DR such that the caudal third of the DR was more similar in afferent innervation to the MR than it was to the rostral two‐thirds of the DR. The rostral part of the DR is associated with networks controlling motor and motivated behavior, while the caudal DR is more closely aligned with regions that regulate rhythmic hippocampal activity. Thus, a major source of heterogeneity within the DR is inclusion of the caudal component, which may be more accurately viewed as a dorsal extension of the MR. J. Comp. Neurol. 523:1488–1504, 2015. © 2015 Wiley Periodicals, Inc.
Luminescent Properties of a Water‐Soluble Conjugated Polymer Incorporating Graphene‐Oxide Quantum Dots
Authors: Li Penglei , Di Stasio Francesco , Eda Goki , Fenwick Oliver , McDonnell Shane O. , Anderson Harry L. , Chhowalla Manish , Cacialli Franco
Published: February 2015

We report the incorporation of graphene‐oxide quantum dots (GOQDs) into films, diluted solutions, and light‐emitting diodes (LEDs) as part of a water‐soluble derivative of poly(p‐phenylene vinylene), or PDV.Li, to investigate their impact on the light‐emission properties of this model conjugated polymer. Despite the well‐known ability of graphene and graphene oxide to quench the photoluminescence of nearby emitters, we find that the addition of GOQDs to diluted solutions of PDV.Li does not significantly affect the photoluminescence (PL) dynamics of PDV.Li, bringing about only a modest quenching of the PL. However, loading the polymer with GOQDs led to a substantial decrease in the turn‐on voltage of LEDs based on GOQD–PDV.Li composites. This effect can be attributed to either the improved morphology of the host polymer, resulting in an increase in the charge mobility, or the enhanced injection through GOQDs near the electrodes.