bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radical Compatibility with Nonaqueous Electrolytes and Its Impact on an All‐Organic Redox Flow Battery
Authors: Wei Xiaoliang , Xu Wu , Huang Jinhua , Zhang Lu , Walter Eric , Lawrence Chad , Vijayakumar M. , Henderson Wesley A. , Liu Tianbiao , Cosimbescu Lelia , Li Bin , Sprenkle Vincent , Wang Wei 
Published: April 2015

AbstractNonaqueous redox flow batteries hold the promise of achieving higher energy density because of the broader voltage window than aqueous systems, but their current performance is limited by low redox material concentration, cell efficiency, cycling stability, and current density. We report a new nonaqueous all‐organic flow battery based on high concentrations of redox materials, which shows significant, comprehensive improvement in flow battery performance. A mechanistic electron spin resonance study reveals that the choice of supporting electrolytes greatly affects the chemical stability of the charged radical species especially the negative side radical anion, which dominates the cycling stability of these flow cells. This finding not only increases our fundamental understanding of performance degradation in flow batteries using radical‐based redox species, but also offers insights toward rational electrolyte optimization for improving the cycling stability of these flow batteries.
Hydroxy‐dirigierte, Fluorid‐katalysierte Epoxid‐Hydrosilylierung zur Synthese von 1,4‐Diolen
Authors: Zhang Yong‐Qiang , Funken Nico , Winterscheid Peter , Gansäuer Andreas 
Published: April 2015

AbstractEine neue, regioselektive, Fluorid‐katalysierte Hydrosilylierung von β‐Epoxyalkoholen wird vorgestellt. Die Reaktion ist modular und in der Synthese von 1,4‐Diolen breit anwendbar. Fluorid ist für diese Reaktion aus zwei Gründen unabdingbar: Erstens fördert es die Bildung eines Silylethers (der eine Si‐H‐Bindung beinhaltet), zweitens ermöglicht es die Ringöffnung durch eine intramolekulare SN2‐Reaktion durch Aktivierung des Silans. Die Reaktion kann an der Luft durchgeführt werden.
On‐Demand Ambient Ionization of Picoliter Samples Using Charge Pulses
Authors: Li Anyin , Hollerbach Adam , Luo Qingjie , Cooks R. Graham 
Published: April 2015

AbstractRelay electrospray ionization (rESI) from a capillary containing a sample solution (or from an array of such capillaries) is triggered by charge deposition onto the capillary. Suitable sources of primary ions, besides electrosprays, are plasma ion and piezoelectric discharge plasma sources. With no requirement for physical contact, high‐throughput sample screening is enabled by rapidly addressing individual secondary (sample) capillaries. Sub‐pL sample volumes can be loaded and sprayed. Polar analytes, including neurotransmitters, phosphopeptides, oligonucleotides, illicit drugs, and pharmaceutical compounds are successfully ionized by rESI with concentration sensitivities (0.1 ppb for acetylcholine) which are similar to nanoESI but absolute sensitivities are orders of magnitude better. Nonpolar analytes (steroids, alkynes) are ionized by rESI using an open‐tube secondary capillary and injecting electrolytically generated metal cations from the primary electrospray.
Three‐body problem periodic orbits with vanishing angular momentum
Authors: Titov V. 
Published: April 2015

AbstractPeriodic solutions of the general three‐body problem are investigated in the shape space. Two different solutions are considered: the first is an extension of the well‐known figure‐eight orbit, and the second one is from the free‐fall problem. Using the shape space, we reduce the dimension of the problem. These orbits are obtained numerically and described on the Euclidean plane and on the shape sphere. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Radio emission at 1.4 GHz from luminous compact galaxies
Authors: Parnovsky S. L. , Izotova I. Y. 
Published: April 2015

AbstractWe analyse the properties of the 1.4 GHz continuum emission in 52 star‐forming compact luminous galaxies (LCGs). The fluxes of the 1.4 GHz thermal (free‐free) component are derived from the extinction‐ and aperture‐corrected fluxes of the Hα emission line. The fraction of the thermal 1.4 GHz emission is shown tobe in the range of 2–52 % with a median value of about 15–17 %, and its distribution is close to a log‐normal one. Both the thermal and non‐thermal radio continuum luminosities are shown to be proportional to the masses of the young stellar population of the LCGs. We discuss the approximation of the ratio of the 1.4 GHz luminosity‐to‐the mass of the young stellar population as a function of starburst age. The derived approximation is shown to be similar but less clearly defined compared to ones obtained previously for LCGs from their Hα and UV continuum luminosities. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Life cycle environmental sustainability of lignocellulosic ethanol produced in integrated thermo‐chemical biorefineries
Authors: Jeswani Harish K. , Falano Temitope , Azapagic Adisa 
Published: April 2015

AbstractThere is a growing interest in producing biofuels and bio‐chemicals from lignocellulosic feedstocks in integrated biorefineries. However, the sustainability implications of integrated biorefineries are still poorly understood. Using a life cycle approach, this paper examines environmental impacts of second‐generation ethanol produced in thermo‐chemical refineries together with chemicals and energy. Four feedstocks are considered: wheat straw, poplar, Miscanthus and forest residue. The results suggest that the production of ethanol from these feedstocks offers significant savings in eight out of 12 environmental impacts when the system is credited for the avoided impacts from producing the co‐products from fossil resources. Ethanol from forest residue is the best and wheat straw the worst option for most impacts. Land use change has a significant effect on the global warming potential (GWP) of ethanol. For example, conversion of forest to grow Miscanthus increases the GWP from –234 to 6685 g CO2 eq./l of ethanol. The effect is opposite when grassland is converted to grow poplar: the GWP is reduced by two times because of carbon sequestration by poplar. The thermo‐chemical route for producing ethanol from poplar and forest residue is more sustainable for most impacts than the bio‐chemical conversion with the same feedstocks. Although ethanol saves up to 83% of GHG emissions per MJ of fuel compared to petrol, the savings are much smaller (~3%) for current ethanol blends of 5%. Therefore, unless a much higher proportion of ethanol was used, the contribution of second‐generation ethanol to climate change mitigation would be small. © 2015 The Authors. Biofuels, Bioproducts, Biorefining published by Society of Chemical Industry and John Wiley & Sons, Ltd.
Metabolic engineering of Clostridium tyrobutyricum for n‐butanol production through co‐utilization of glucose and xylose
Authors: Yu Le , Xu Mengmeng , Tang I‐Ching , Yang Shang‐Tian 
Published: April 2015

ABSTRACTThe glucose‐mediated carbon catabolite repression (CCR) in Clostridium tyrobutyricum impedes efficient utilization of xylose present in lignocellulosic biomass hydrolysates. In order to relieve the CCR and enhance xylose utilization, three genes (xylT, xylA, and xylB) encoding a xylose proton‐symporter, a xylose isomerase and a xylulokinase, respectively, from Clostridium acetobutylicum ATCC 824 were co‐overexpressed with aldehyde/alcohol dehydrogenase (adhE2) in C. tyrobutyricum (Δack). Compared to the strain Ct(Δack)‐pM2 expressing only adhE2, the mutant Ct(Δack)‐pTBA had a higher xylose uptake rate and was able to simultaneously consume glucose and xylose at comparable rates for butanol production. Ct(Δack)‐pTBA produced more butanol (12.0 vs. 3.2 g/L) with a higher butanol yield (0.12 vs. 0.07 g/g) and productivity (0.17 vs. 0.07 g/L · h) from both glucose and xylose, while Ct(Δack)‐pM2 consumed little xylose in the fermentation. The results confirmed that the CCR in C. tyrobutyricum could be overcome through overexpressing xylT, xylA, and xylB. The mutant was also able to co‐utilize glucose and xylose present in soybean hull hydrolysate (SHH) for butanol production, achieving a high butanol titer of 15.7 g/L, butanol yield of 0.24 g/g, and productivity of 0.29 g/L · h. This study demonstrated the potential application of Ct(Δack)‐pTBA for industrial biobutanol production from lignocellulosic biomass. Biotechnol. Bioeng. 2015;112: 2134–2141. © 2015 Wiley Periodicals, Inc.
More similar than different: Host cell protein production using three null CHO cell lines
Authors: Yuk Inn H. , Nishihara Julie , Walker Jr Donald , Huang Eric , Gunawan Feny , Subramanian Jayashree , Pynn Abigail F.J. , Yu X.Christopher , Zhu‐Shimoni Judith , Vanderlaan Martin , Krawitz Denise C. 
Published: April 2015

ABSTRACTTo understand the diversity in the cell culture harvest (i.e., feedstock) provided for downstream processing, we compared host cell protein (HCP) profiles using three Chinese Hamster Ovary (CHO) cell lines in null runs which did not generate any recombinant product. Despite differences in CHO lineage, upstream process, and culture performance, the cell lines yielded similar cell‐specific productivities for immunogenic HCPs. To compare the dynamics of HCP production, we searched for correlations between the time‐course profiles of HCP (as measured by multi‐analyte ELISA) and those of two intracellular HCP species, phospholipase B‐like 2 (PLBL2) and lactate dehydrogenase (LDH). Across the cell lines, proteins in the day 14 supernatants analyzed by two‐dimensional polyacrylamide gel electrophoresis (2D‐PAGE) showed different spot patterns. However, subsequent analysis by liquid chromatography coupled with tandem mass spectrometry (LC‐MS/MS) indicated otherwise: the total number of peptides and proteins identified were comparable, and 80% of the top 1,000 proteins identified were common to all three lines. Finally, to assess the impact of culture viability on extracellular HCP profiles, we analyzed supernatants from a cell line whose viability dropped after day 10. The amounts of HCP and PLBL2 (quantified by their respective ELISAs) as well as the numbers and major populations of HCPs (identified by LC‐MS/MS) were similar across days 10, 14, and 17, during which viabilities declined from ∼80% to <20% and extracellular LDH levels increased several‐fold. Our findings indicate that the CHO‐derived HCPs in the feedstock for downstream processing may not be as diverse across cell lines and upstream processes, or change as dramatically upon viability decline as originally expected. In addition, our findings show that high density CHO cultures (>107 cells/mL)—operated in fed‐batch mode and exhibiting high viabilities (>70%) throughout the culture duration—can accumulate a considerable amount of immunogenic HCP (∼1–2 g/L) in the extracellular environment at the time of harvest (day 14). This work also demonstrates the potential of using LC‐MS/MS to overcome the limitations associated with ELISA and 2D‐PAGE for HCP analysis. Biotechnol. Bioeng. 2015;112: 2068–2083. © 2015 Wiley Periodicals, Inc.
Interlinked population balance and cybernetic models for the simultaneous saccharification and fermentation of natural polymers
Authors: Ho Yong Kuen , Doshi Pankaj , Yeoh Hak Koon , Ngoh Gek Cheng 
Published: April 2015

ABSTRACTSimultaneous Saccharification and Fermentation (SSF) is a process where microbes have to first excrete extracellular enzymes to break polymeric substrates such as starch or cellulose into edible nutrients, followed by in situ conversion of those nutrients into more valuable metabolites via fermentation. As such, SSF is very attractive as a one‐pot synthesis method of biological products. However, due to the co‐existence of multiple biochemical steps, modeling SSF faces two major challenges. The first is to capture the successive chain‐end and/or random scission of the polymeric substrates over time, which determines the rate of generation of various fermentable substrates. The second is to incorporate the response of microbes, including their preferential substrate utilization, to such a complex broth. Each of the above‐mentioned challenges has manifested itself in many related areas, and has been competently but separately attacked with two diametrically different tools, i.e., the Population Balance Modeling (PBM) and the Cybernetic Modeling (CM), respectively. To date, they have yet to be applied in unison on SSF resulting in a general inadequacy or haphazard approaches to examine the dynamics and interactions of depolymerization and fermentation. To overcome this unsatisfactory state of affairs, here, the general linkage between PBM and CM is established to model SSF. A notable feature is the flexible linkage, which allows the individual PBM and CM models to be independently modified to the desired levels of detail. A more general treatment of the secretion of extracellular enzyme is also proposed in the CM model. Through a case study on the growth of a recombinant Saccharomyces cerevisiae capable of excreting a chain‐end scission enzyme (glucoamylase) on starch, the interlinked model calibrated using data from the literature (Nakamura et al., Biotechnol. Bioeng. 53:21‐25, 1997), captured features not attainable by existing approaches. In particular, the effect of various enzymatic actions on the temporal evolution of the polymer distribution and how the microbes respond to the diverse polymeric environment can be studied through this framework. Biotechnol. Bioeng. 2015;112: 2084–2105. © 2015 Wiley Periodicals, Inc.
Enforced ATP futile cycling increases specific productivity and yield of anaerobic lactate production in Escherichia coli
Authors: Hädicke Oliver , Bettenbrock Katja , Klamt Steffen 
Published: April 2015

ABSTRACTThe manipulation of cofactor pools such as ATP or NAD(P)H has for long been recognized as key targets for metabolic engineering of microorganisms to improve yields and productivities of biotechnological processes. Several works in the past have shown that enforcing ATP futile cycling may enhance the synthesis of certain products under aerobic conditions. However, case studies demonstrating that ATP wasting may also have beneficial effects for anaerobic production processes are scarce. Taking lactic acid as an economically relevant product, we demonstrate that induction of ATP futile cycling in Escherichia coli leads to increased yields and specific production rates under anaerobic conditions, even in the case where lactate is already produced with high yields. Specifically, we constructed a high lactate producer strain KBM10111 (= MG1655 ΔadhE::Cam ΔackA‐pta) and implemented an IPTG‐inducible overexpression of ppsA encoding for PEP synthase which, together with pyruvate kinase, gives rise to an ATP consuming cycle. Under induction of ppsA, KBM10111 exhibits a 25% higher specific lactate productivity as well as an 8% higher lactate yield. Furthermore, the specific substrate uptake rate was increased by 14%. However, trade‐offs between specific and volumetric productivities must be considered when ATP wasting strategies are used to shift substrate conversion from biomass to product synthesis and we discuss potential solutions to design optimal processes. In summary, enforced ATP futile cycling has great potential to optimize a variety of production processes and our study demonstrates that this holds true also for anaerobic processes. Biotechnol. Bioeng. 2015;112: 2195–2199. © 2015 Wiley Periodicals, Inc.
Sparse canonical correlation analysis applied to ‐omics studies for integrative analysis and biomarker discovery
Authors: Cao Dong‐Sheng , Liu Shao , Zeng Wen‐Bin , Liang Yi‐Zeng 
Published: April 2015

AbstractWith the rapid development of new ‐omics measurement methods, there is an increasing interest in studying the correlation structure between two or more data sets. Multivariate methods such as canonical correlation analysis (CCA) have been proposed to analyze the intrinsic correlation relationship by integrating two data sets. However, because of the high dimensionality of data and the relative scarcity of samples, the ordinary CCA is usually faced with variable selection problems and thereby fails to obtain a satisfactory relationship. Here, we explored the potential of sparse CCA (SCCA) to find the correlative components in two sparse views. SCCA aims at finding sparse projection directions to well extract the correlation between two data sets. We applied this method to one simulation data and one real ‐omics data to illustrate the performance of SCCA. The results from two studies show that SCCA could effectively find the correlated patterns between two data sets, which are of high importance for understanding the relationship between two underlying chemical or biological processes. The corresponding variable subsets selected by sparse weight vectors can assist in a better interpretation of the chemical or biological process. The integrative analysis from two views by SCCA helps in improving the discriminative ability of classification models for various ‐omics studies. Copyright © 2015 John Wiley & Sons, Ltd.
Apolar Bimesogens and the Incidence of the Twist–Bend Nematic Phase
Authors: Mandle Richard J. , Davis Edward J. , Archbold Craig T. , Voll Constantin C. A. , Andrews Jessica L. , Cowling Stephen J. , Goodby John W. 
Published: April 2015

AbstractThe nematic twist–bend phase (NTB) was, until recently, only observed for polar mesogenic dimers, trimers or bent‐core compounds. In this article, we report a comprehensive study on novel apolar materials that also exhibit NTB phases. The NTB phase was observed for materials containing phenyl, cyclohexyl or bicyclooctyl rings in their rigid‐core units. However, for materials with long (>C7) terminal chains or mesogenic core units comprising three ring units, the NTB phase was not observed and instead the materials exhibited smectic phases. One compound was found to exhibit a transition from the NTB phase to an anticlinic smectic C phase; this is the first example of this polymorphism. Incorporation of lateral substitution with respect to the central core unit led to reductions in transition temperatures; however, the NTB phase was still found to occur. Conversely, utilising branched terminal groups rendered the materials non‐mesogenic. Overall, it appears that it is the gross molecular topology that drives the incidence of the NTB phase rather than simple dipolar considerations. Furthermore, dimers lacking any polar groups, which were prepared to test this hypothesis, were found to be non mesogenic, indicating that at the extremes of polarity these effects can dominate over topology.
Substituted Tetraaza‐ and Hexaazahexacenes and their N,N′‐Dihydro Derivatives: Syntheses, Properties, and Structures
Authors: Engelhart Jens U. , Lindner Benjamin D. , Schaffroth Manuel , Schrempp David , Tverskoy Olena , Bunz Uwe H. F. 
Published: April 2015

AbstractThe palladium‐catalyzed coupling of a substituted o‐diaminoanthracene and a substituted o‐diaminophenazine to substituted 2,3‐dichloroquinoxalines furnishes 10 differently substituted N,N′‐dihydrotetraaza‐ or ‐hexaazahexacenes with the quinoxaline group of the azaacenes carrying fluorine, chlorine, or nitro groups. The N,N′‐dihydrotetraazahexacenes with hydrogen, chlorine, and fluorine subtituents are oxidized to azaacenes, whereas only the parent N,N′‐dihydrohexaazahexacenes, with hydrogen substituents, are oxidized by MnO2. The resultant azaacenes are characterized by their optical and spectroscopic data. In addition, single‐crystal X‐ray structures have been obtained for the parent tetraazahexacenes and their difluoro‐substituted derivatives. The di‐ and tetrachloro derivatives of the N,N′‐dihydrohexaazahexacene have also been structurally characterized.
Highly Stereoselective β‐Mannopyranosylation via the 1‐α‐Glycosyloxy‐isochromenylium‐4‐gold(I) Intermediates
Authors: Zhu Yugen , Yu Biao 
Published: April 2015

AbstractWhile the gold(I)‐catalyzed glycosylation reaction with 4,6‐O‐benzylidene tethered mannosyl ortho‐alkynylbenzoates as donors falls squarely into the category of the Crich‐type β‐selective mannosylation when Ph3PAuOTf is used as the catalyst, in that the mannosyl α‐triflates are invoked, replacement of the −OTf in the gold(I) complex with less nucleophilic counter anions (i.e., −NTf2, −SbF6, −BF4, and −BAr4F) leads to complete loss of β‐selectivity with the mannosyl ortho‐alkynylbenzoate β‐donors. Nevertheless, with the α‐donors, the mannosylation reactions under the catalysis of Ph3PAuBAr4F (BAr4F=tetrakis[3,5‐bis(trifluoromethyl)phenyl]borate) are especially highly β‐selective and accommodate a broad scope of substrates; these include glycosylation with mannosyl donors installed with a bulky TBS group at O3, donors bearing 4,6‐di‐O‐benzoyl groups, and acceptors known as sterically unmatched or hindered. For the ortho‐alkynylbenzoate β‐donors, an anomerization and glycosylation sequence can also ensure the highly β‐selective mannosylation. The 1‐α‐mannosyloxy‐isochromenylium‐4‐gold(I) complex (Cα), readily generated upon activation of the α‐mannosyl ortho‐alkynylbenzoate (1 α) with Ph3PAuBAr4F at −35 °C, was well characterized by NMR spectroscopy; the occurrence of this species accounts for the high β‐selectivity in the present mannosylation.
Towards Norcorrin: Hydrogenation Chemistry and the Heterodimerization of Nickel(II) Norcorrole
Authors: Liu Bin , Li Xiaofang , Stępień Marcin , Chmielewski Piotr J. 
Published: April 2015

Abstract5,14‐Dimesitylnorcorrolatonickel(II) was hydrogenated under mild conditions (room temperature, 1 atm H2, THF solution, 5 min.) in the presence of Raney nickel to yield nonaromatic derivatives that were isolated and characterized by NMR spectroscopy, UV/Vis spectrophotometry, HRMS, cyclic voltammetry, and X‐ray diffraction analysis. The major hydrogenation product, 1,2,3,7,8,9‐hexahydronorcorrolatonickel(II), underwent dimerization in the presence of p‐chloranil to give a nonsymmetrically linked 2,3′‐bis(norcorrole) system that can adopt eight different oxidation states over a redox potential window of 3 V and has a HOMO–LUMO gap of 0.92 V.
Practical Iron‐ and Cobalt‐Catalyzed Cross‐Coupling Reactions between N‐Heterocyclic Halides and Aryl or Heteroaryl Magnesium Reagents
Authors: Kuzmina Olesya M. , Steib Andreas K. , Fernandez Sarah , Boudot Willy , Markiewicz John T. , Knochel Paul 
Published: April 2015

AbstractThe reaction scope of iron‐ and cobalt‐catalyzed cross‐coupling reactions in the presence of isoquinoline (quinoline) in the solvent mixture tBuOMe/THF has been further investigated. Various 2‐halogenated pyridine, pyrimidine, and triazine derivatives were arylated under these mild conditions in excellent yields. The presence of isoquinoline allows us to perform Fe‐catalyzed cross‐coupling reactions between 6‐chloroquinoline and aryl magnesium reagents. Furthermore, it was found that the use of 10 % N,N‐dimethylquinoline‐8‐amine increases the yields of some Co‐catalyzed cross‐coupling reactions with chloropyridines bearing electron‐withdrawing substituents.
Photoemission Studies on N‐Substituted Dithienylated Phenothiazines
Authors: Fingerle Mathias , Hemgesberg Maximilian , Schmitt Yvonne , Lach Stefan , Gerhards Markus , Thiel Werner R. , Ziegler Christiane 
Published: April 2015

AbstractDithienylated phenothiazines (DTPTs) with different functional groups attached to the central nitrogen atom are presented as a class of versatile metal‐free chromophores for the design of dye‐sensitized solar cells (DSSCs) and organic light‐emitting diodes (OLEDs). The electronic characteristics of spin‐coated thin films on polycrystalline gold were studied using photoelectron spectroscopy assisted by theoretical calculations, scanning force microscopy, and UV/Vis spectroscopy. Complementary fluorescence spectra show light emission in the blue region (465 nm). The absorption properties and good hole‐transporting abilities make DTPTs feasible hole‐transporting materials (HTM) and metal‐free chromophores in UV‐sensitive solar cell designs.