bluuebunny/crossref_metadata_2025 huggingface dataset:
Mega‐scale Moho relief and the structure of the lithosphere on the eastern flank of the Viking Graben, offshore southwestern Norway
Authors: Gabrielsen Roy H. , Fossen Haakon , Faleide Jan Inge , Hurich Charles A.
Published: April 2015

The International Lithosphere Project deep reflection seismic survey in the Norwegian sector of the North Sea has been reprocessed, particularly focusing on the deep crust, the reflection Moho, and the upper mantle. The data display shifting reflection patterns of the crust and the upper mantle parallel to the eastern margin of the Viking Graben. In the upper crust, which is mainly seismically transparent by the processing techniques utilized here, large‐scale structural features like detachment shear zones and master faults can be identified. Several of the major onshore faults and shear zones match seismic features in the seismic lines. Many of these structures acted as extensional shear zones in the Devonian. The middle crust is of variable reflectivity, whereas the lower crust is generally strongly reflective and is particularly so in the southern domain. The reflection Moho is identified throughout the study area but is of variable character. The presence of a S(E) dipping structure (Hardanger Moho Offset) that displaces the Moho by approximately 10 km, extends deep into the mantle (below the 50 km line depth), is positioned where the shallower Hardangerfjord Shear Zone, which flattens on the level of the middle crust, is situated. The Hardangerfjord Shear Zone/Hardanger Moho Offset‐system coincides with change of the crustal thickness (depth to Moho), a change that also coincides with the transition from thin‐ to thick‐skinned Caledonian deformation. Intramantle reflections are common in the study area, some of which are interpreted as shear zones, whereas others most likely represent magmatic intrusions.
Tectonic interactions between India and Arabia since the Jurassic reconstructed from marine geophysics, ophiolite geology, and seismic tomography
Authors: Gaina Carmen , van Hinsbergen Douwe J. J. , Spakman Wim
Published: April 2015

Gondwana breakup since the Jurassic and the northward motion of India toward Eurasia were associated with formation of ocean basins and ophiolite obduction between and onto the Indian and Arabian margins. Here we reconcile marine geophysical data from preserved oceanic basins with the age and location of ophiolites in NW India and SE Arabia and seismic tomography of the mantle below the NW Indian Ocean. The North Somali and proto‐Owen basins formed due to 160–133 Ma N‐S extension between India and Somalia. Subsequent convergence destroyed part of this crust, simultaneous with the uplift of the Masirah ophiolites. Most of the preserved crust in the Owen Basin may have formed between 84 and 74 Ma, whereas the Mascarene and the Amirante basins accommodated motion between India and Madagascar/East Africa between 85 and circa 60 Ma and 75 and circa 66 Ma, respectively. Between circa 84 and 45 Ma, oblique Arabia‐India convergence culminated in ophiolite obduction onto SE Arabia and NW India and formed the Carlsberg slab in the lower mantle below the NW Indian Ocean. The NNE‐SSW oriented slab may explain the anomalous bathymetry in the NW Indian Ocean and may be considered a paleolongitudinal constraint for absolute plate motion. NW India‐Asia collision occurred at circa 20 Ma deforming the Sulaiman ranges or at 30 Ma if the Hindu Kush slab north of the Afghan block reflects intra‐Asian subduction. Our study highlights that the NW India ophiolites have no relationship with India‐Asia motion or collision but result from relative India‐Africa/Arabia motions instead.
Environmental conditions impacting juvenile Chinook salmon growth off central California: An ecosystem model analysis
Authors: Fiechter J. , Huff D. D. , Martin B. T. , Jackson D. W. , Edwards C. A. , Rose K. A. , Curchitser E. N. , Hedstrom K. S. , Lindley S. T. , Wells B. K.
Published: April 2015

A fully coupled ecosystem model is used to identify the effects of environmental conditions and upwelling variability on growth of juvenile Chinook salmon in central California coastal waters. The ecosystem model framework consists of an ocean circulation submodel, a biogeochemical submodel, and an individual‐based submodel for salmon. Simulation results indicate that years favorable for juvenile salmon growth off central California are characterized by particularly intense early season upwelling (i.e., March through May), leading to enhanced krill concentrations during summer near the location of ocean entry (i.e., Gulf of the Farallones). Seasonally averaged growth rates in the model are generally consistent with observed values and suggest that juvenile salmon emigrating later in the season (i.e., late May and June) achieve higher weight gains during their first 90 days of ocean residency.
Heat content variability in the North Atlantic Ocean in ocean reanalyses
Authors: Häkkinen Sirpa , Rhines Peter B. , Worthen Denise L.
Published: April 2015

Warming of the North Atlantic Ocean from the 1950s to 2012 is analyzed on neutral density surfaces and vertical levels in the upper 2000 m. Three reanalyses and two observational data sets are compared. The net gain of 5 × 1022 J in the upper 2000 m is roughly 30% of the global ocean warming over this period. Upper ocean heat content (OHC) is dominated in most regions by heat transport convergence without widespread changes in the potential temperature/salinity relation. The heat convergence is associated with sinking of midthermocline isopycnals, with maximum sinking occurring at potential densities σ0 = 26.4−27.3, which contain subtropical mode waters. Water masses lighter than σ0 = 27.3 accumulate heat by increasing their volume, while heavier waters lose heat by decreasing their volume. Spatially, the OHC trend is nonuniform: the low latitudes, 0–30°N are warming steadily while large multidecadal variability occurs at latitudes 30–65°N.
Limited impact of escaping photoelectrons on the terrestrial polar wind flux in the polar cap
Authors: Kitamura N. , Seki K. , Nishimura Y. , McFadden J. P.
Published: April 2015

A statistical analysis using a long‐term (over one solar cycle) photoelectron data set obtained by the Fast Auroral SnapshoT satellite demonstrates that photoelectron outflows has little impact on the polar wind ion flux. This result implies that it is the source region of H+ ions in the topside ionosphere and not the photoelectron flux that controls the terrestrial polar wind flux. The polar wind ion flux, estimated from electron outflow does not change with increasing net photoelectron production due to increasing solar activity. The magnitude of a self‐created field‐aligned potential drop is likely determined so as to equilibrate electron fluxes with ion fluxes regulated by a net production rate of H+ ions. The result suggests that the polar wind H+ ion flux from magnetized terrestrial planets, including Earth‐like exoplanets, can be estimated once the composition and temperature of its atmosphere, which determine the net ion production rate, are known.
Development of a Polar Stratospheric Cloud Model within the Community Earth System Model using constraints on Type I PSCs from the 2010–2011 Arctic winter
Authors: Zhu Yunqian , Toon Owen B. , Lambert Alyn , Kinnison Douglas E. , Brakebusch Matthias , Bardeen Charles G. , Mills Michael J. , English Jason M.
Published: April 2015

Polar stratospheric clouds (PSCs) are critical elements of Arctic and Antarctic ozone depletion. We establish a PSC microphysics model using coupled chemistry, climate, and microphysics models driven by specific dynamics. We explore the microphysical formation and evolution of STS (Supercooled Ternary Solution) and NAT (Nitric Acid Trihydrate). Characteristics of STS particles dominated by thermodynamics compare well with observations. For example, the mass of STS is close to the thermodynamic equilibrium assumption when the particle surface area is >4 µm2/cm3. We derive a new nucleation rate equation for NAT based on observed denitrification in the 2010–2011 Arctic winter. The homogeneous nucleation scheme leads to supermicron NAT particles as observed. We also find that as the number density of NAT particles increases, the denitrification also increases. Simulations of the PSC lidar backscatter, denitrification, and gas phase species are generally within error bars of the observations. However, the simulations are very sensitive to temperature, which limits our ability to fully constrain some parameters (e.g., denitrification, ozone amount) based on observations.
Templates as Shadow Masks to Tune the Magnetic Anisotropy in Nanostructured CoCrPt/Ti Bilayer Films
Authors: Navas David , Bi Lei , Adeyeye Adekunle O. , Ross Caroline A.
Published: April 2015

Off‐axis deposition of Ti and CoCrPt films onto lithographically patterned templates has been used to make nanostructures with a lateral thickness variation that allows the tuning of the magnetic anisotropy. CoCrPt rectangles of 1 μm × 725 nm without a thickness variation show an out‐of‐plane easy axis and a single‐domain configuration after demagnetization. On the other hand, rectangles with a thickness variation along their longer dimension show an out‐of‐plane multidomain state, but an in‐plane vortex configuration occurs when the thickness variation is along the shorter dimension. The evolution of the magnetic behavior is understood from the change in both Ti and CoCrPt thicknesses and their effects on the magnetic anisotropy, and provides a simple method for controlling the magnetic state and reversal process of patterned nanostructures.
Preparation of Bis‐GMA‐Free Dental Restorative Composites with Dendritic Macromer (G‐IEMA)
Authors: Yu Biao , Liu Fang , He Jingwei , He Yingcong , Lin Zhengmei
Published: April 2015

To reduce human exposure risk to bisphenol A derivatives, a new 2,2‐bis[p‐(2’‐hydroxy‐3’‐methacryloxypropoxy) phenylene]propane (Bis‐GMA) free dental composites material GEC‐66% was prepared using a dendritic macromer (G‐IEMA) as one component of resin matrix. Properties of GEC‐66%, such as double bond conversion (DC), polymerization shrinkage, water sorption (WS) and solubility, flexural strength (FS) and modulus, and cytotoxicity on human dental pulp cells were evaluated. The commercial Bis‐GMA contained restorative material 3M ESPS FiltekTM Z250 was used as a control. The results showed that GEC‐66% had higher DC and WS, comparable shrinkage and solubility, and less cytotoxicity, when compared with Z250. Though FS of GEC‐66% was lower than that of Z250, it still met the ISO requirement for polymer‐based restorative materials. All of these proved that GEC‐66% had potential to be used in clinic.
Photooxidative Amidation of Aldehydes with Amines Catalyzed by Rose Bengal
Authors: Leung Franco King‐Chi , Cui Jian‐Fang , Hui Tze‐Wai , Kung Karen Ka‐Yan , Wong Man‐Kin
Published: April 2015

An efficient method for photooxidative amidation of aldehydes with secondary amines has been developed. With the use of a readily available photocatalyst rose bengal, tertiary amides (with examples of oligosaccharides and endoperoxide artemisinin) were obtained in good yields with high chemoselectivity and functional‐group compatibility under mild reaction conditions.
Efficient Palladium‐Catalyzed Synthesis of Sulfonyl‐Substituted Vinyl Arenes: Hydrazones Provide the Cross‐Coupling Partner and Nucleophile Components
Authors: Wu Xin‐Xing , Chen Si , Chen Wen‐Long , Wang Li‐Jing , Gao Pin , Xu Peng‐Fei , Liang Yong‐Min
Published: April 2015

A practical and efficient approach for the synthesis of various sulfonyl‐substituted vinyl arenes is reported. In the process, hydrazones provide coupling partners for the Pd‐catalyzed cross‐coupling with aryl halides and sulfinate salts as nucleophiles, which realizes minimal waste and excellent atom economy.
Highly Ordered Mesoporous Few‐Layer Graphene Frameworks Enabled by Fe3O4 Nanocrystal Superlattices
Authors: Jiao Yucong , Han Dandan , Liu Limin , Ji Li , Guo Guannan , Hu Jianhua , Yang Dong , Dong Angang
Published: April 2015

While great progress has been achieved in the synthesis of ordered mesoporous carbons in the past decade, it still remains a challenge to prepare highly graphitic frameworks with ordered mesoporosity and high surface area. Reported herein is a simple synthetic methodology, based on the conversion of self‐assembled superlattices of Fe3O4 nanocrystals, to fabricate highly ordered mesoporous graphene frameworks (MGFs) with ultrathin pore walls consisting of three to six stacking graphene layers. The MGFs possess face‐centered‐cubic symmetry with interconnected mesoporosity, tunable pore width, and high surface area. Because of their unique architectures and superior structural durability, the MGFs exhibit excellent cycling stability and rate performance when used as anode materials for lithium‐ion batteries, thus retaining a specific capacity of 520 mAh g−1 at a current density of 300 mA g−1 after 400 cycles.
Next‐Generation Sequencing as Input for Chemometrics in Differential Sensing Routines
Authors: Goodwin Sara , Gade Alexandra M. , Byrom Michelle , Herrera Baine , Spears Camille , Anslyn Eric V. , Ellington Andrew D.
Published: April 2015

Differential sensing (DS) methods traditionally use spatially arrayed receptors and optical signals to create score plots from multivariate data which classify individual analytes or complex mixtures. Herein, a new approach is described, in which nucleic acid sequences and sequence counts are used as the multivariate data without the necessity of a spatial array. To demonstrate this approach to DS, previously selected aptamers, identified from the literature, were used as semi‐specific receptors, Next‐Gen DNA sequencing was used to generate data, and cell line differentiation was the test‐bed application. The study of a principal component analysis loading plot revealed cross‐reactivity between the aptamers. The technique generates high‐dimensionality score plots, and should be applicable to any mixture of complex and subtly different analytes for which nucleic acid‐based receptors exist.
Effect of processing conditions on the dispersion of carbon nanotubes in polyacrylonitrile solutions
Authors: Yan Xuejia , Dong Hongming , Liu Yaodong , Newcomb Bradley A. , Chae Han Gi , Kumar Satish , Xiao Zhiwei , Liu Tao
Published: April 2015

As a result of van der Waal's interactions, carbon nanotubes (CNTs) tend to assemble into bundle/rope structures. It is essential to de‐bundle and exfoliate CNTs in polymer solutions in order to utilize their reinforcement potential as far as possible. In this study, a variety of different processing conditions were used to prepare polyacrylonitrile/CNTs composite solutions. The CNT bundle diameter, length, and macro‐scale dispersion homogeneity in those solutions were compared. It was observed that the CNT type, solvent type, and polymer concentration were important factors to determine the CNT bundle sizes in the solutions. The results are expected to be beneficial to obtain well‐dispersed polymer/CNT nanocomposites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42177.
Manipulation of Shell Morphology of Silicate Spheres from Structural Evolution in a Purely Inorganic System
Authors: Ji Qingmin , Ishihara Shinsuke , Terentyeva Tatyana G. , Deguchi Kenzo , Ohki Shinobu , Tansho Masataka , Shimizu Tadashi , Hill Jonathan P. , Ariga Katsuhiko
Published: April 2015

We have investigated the structural transformation of solid silica spheres into various more complex spherical structures including flower‐like, thick or thin nanosheet‐shelled and porous shelled spheres. In the absence of organic additives, sodium salts contained in this inorganic reaction system apparently direct the silica dissolution and regrowth of dissolved silicate at the nanometer‐scale, leading to the formation of a nanosheet network rather than solid aggregates. Subsequent removal of the salts by simple water washing results in voids in the siloxane network and a significant availability of surface silanol groups so that the resulting nanosheets and spheres composed of them possess large surface areas, pore volumes, and morphological flexibility, which can be varied by an applied stimulus. The results represent a rare example of the transformation of a simple silicate structure into a much more complex spherical structure involving a purely inorganic reaction system.
In Situ Formation of Efficient Cobalt‐Based Water Oxidation Catalysts from Co2+‐Containing Tungstate and Molybdate Solutions
Authors: Zhang Biaobiao , Wu Xiujuan , Li Fei , Yu Fengshou , Wang Yong , Sun Licheng
Published: April 2015

Replacing rare and expensive noble‐metal catalysts with inexpensive and earth‐abundant ones is of great importance to split water either electrochemically or photoelectrochemically. In this study, two amorphous cobalt oxide catalysts (Co−W film and Co−Mo film) with high activity for electrocatalytic water oxidation were prepared by fast, simple electrodeposition from aqueous solutions of Na2WO4 and Na2MoO4 containing Co2+. In solutions of Na2WO4 and Na2MoO4, sustained anodic current densities up to 1.45 and 0.95 mA cm−2 were obtained for Co−W film at 1.87 V versus a reversible hydrogen electrode (RHE) and Co−Mo film on fluorine‐doped tin oxide (FTO) substrates at 1.85 V versus RHE. For the Co−W film, a much higher current density of 4.5 mA cm−2 was acquired by using a stainless‐steel mesh as the electrode substrate. Significantly, in long‐term electrolysis for 13 h, the Co−W film exhibited improved stability in cobalt‐free buffer solution in comparison with the previously reported Co−Pi film.
Expression and characterization of hepatitis E virus‐like particles and non‐virus‐like particles from insect cells
Authors: Qi Ying , Fan Jinping , Huang Weijin , Zhao Chenyan , Wang Youchun , Kong Franklin T. , Kong Wei , Jiang Chunlai
Published: April 2015

The hepatitis E virus (HEV) capsid antigen expressed in insect cell has been proposed as a candidate subunit vaccine for the prevention of hepatitis E. However, the expression and purification of HEV virus‐like particles (VLPs) from insect cells have not been explored. We aimed to optimize the procedure to obtain HEV VLPs. In this study, two conformations of the HEV capsid proteins were expressed in insect cells, VLPs and non‐VLPs, and they were purified separately. The physicochemical properties and the humoral immune responses induced by the two forms were analyzed and compared. We found that HEV VLPs were more immunogenic in mice than HEV non‐VLPs. Therefore, we optimized the conditions that yielded high VLPs expression in insect cell cultures and developed an efficient purification method. The results suggest that the distinction and isolation of VLPs from non‐VLPs are essential to generate a more immunogenic vaccine.
An organic solvent‐stable lipase from a newly isolated Staphylococcus aureus ALA1 strain with potential for use as an industrial biocatalyst
Authors: Ben Bacha Abir , Moubayed Nadine MS , Al‐Assaf Alaa
Published: April 2015

In this study, a new strain, ALA1, was identified as Staphylococcus aureus by biochemical tests, and its 16S ribosomal DNA sequence was isolated from dromedary milk. ALA1 lipase production was optimized in shake flask experiments and measured with varying pH (3–11), temperature (20–55 °C) and substrate concentrations. The maximum lipase production was recorded at pH 8 and 30 °C for up to 30 H of culture period for the S. aureus ALA1 strain. Among the substrates tested, selected carbon sources, xylose, nitrogen source, yeast extract, and olive oil (1%) were suitable for maximizing lipase production. The effects of surfactants were investigated and showed that Tween 20, Tween 80, and Triton X‐100 prevented lipase production. Interestingly, isolate ALA1 was able to grow in high concentrations of benzene or toluene (up to 50% (v/v)). Moreover, the lipolytic activity of the S. aureus ALA1 lipase was stimulated by diethyl ether, whereas almost 100% of S. aureus ALA1 lipase activity was retained in 25% acetone, acetonitrile, benzene, 2‐propanol, ethanol, methanol, or toluene. Because of its stability in organic solvent, the S. aureus ALA1 lipase was used as a biocatalyst to synthesize high levels of added value molecules. S. aureus ALA1 lipase could be considered as an ideal choice for applications in detergent formulations because of its high stability and compatibility with various surfactants, oxidizing agents, and commercial detergents.
Ergebnisse einer energetischen Sanierung: Abweichung zwischen Energiebedarf und Verbrauch – ist nur der Nutzer Schuld?
Authors: Osterhage Tanja , Calì Davide , Streblow Rita , Müller Dirk
Published: April 2015

Auf den Gebäudebereich entfallen in Europa rund 40 % des Endenergieverbrauchs und somit etwa ein Drittel der CO2‐Emissionen. In Deutschland wurden drei Viertel der Bestandsgebäude vor 1979 erstellt, die meisten dieser Gebäude sind gar nicht oder kaum energetisch saniert. Die Sanierungsquote ist momentan sehr gering und liegt bei knapp 1,1 %. Hier setzen die aktuellen politischen Bemühungen an. Zur Bewertung der Effizienz unterschiedlicher energetischer Sanierungsmaßnahmen und in Vorbereitung eines Sanierungsleitfadens wurden im Zuge eines vom Bundesministerium für Wirtschaft und Energie geförderten Forschungsvorhabens drei Wohngebäuderiegel mit 90 Wohneinheiten aus den 1950/60er‐Jahren unterschiedlich saniert. Ein hochauflösendes Monitoring ermöglicht eine detaillierte Analyse und dient zur Überprüfung der Effizienz der eingebauten Technik. Jahresendenergieverbrauchsanalysen lassen deutliche Unterschiede zwischen den verschiedenen Sanierungsvarianten und dem berechneten Energiebedarf erkennen.

Energy − related renovation with discrepancies between calculated energy demand and observed energy consumption. In Europe, 40 % of the final energy consumption is attributed to the building sector, which contributes to one third of the total European carbon dioxide emissions. Two third of existing buildings in Germany, have been built before 1979, the most of those buildings have not yet been energetically retrofitted. The retrofit rate is 1.1 % per year and political and economic measures are under development, to increase this rate. Three identical buildings, with 90 apartments and built at the end of the 1950ies, have been retrofitted with several layouts within a project financed by the German Federal Ministry for Economic Affairs and Energy, with the aim to create new guidelines for optimal residential buildings retrofit. The variety of the refurbishments’ layouts, combined with the high time resolution monitoring system, enabled deep analyses of refurbishment technologies under real conditions. The analysis of the monitored data shows big discrepancies in the energy figures: those discrepancies are presented both comparing the observed energy consumption of each retrofit layout with each other and comparing the observed with expected, calculated energy demand.
Absorption and cleavage of enalapril, a carboxyl ester prodrug, in the rat intestine: in vitro, in situ intestinal perfusion and portal vein cannulation models
Authors: Holenarsipur Vinay K. , Gaud Nilesh , Sinha Jaydeep , Sivaprasad Sankara , Bhutani Priyadeep , Subramanian Murali , Singh Sheelendra Pratap , Arla Rambabu , Paruchury Sundeep , Sharma Tarun , Marathe Punit , Mandlekar Sandhya
Published: April 2015

In recent years prodrug strategy has been used extensively to improve the pharmacokinetic properties of compounds exhibiting poor bioavailability. Mechanistic understanding of the absorption and the role of intestine and liver in the activation of oral prodrugs is crucial. Enalapril, a carboxyl ester prodrug, is reported to be metabolized by human carboxylesterase‐1 (CES1) but not by carboxylesterase‐2 (CES2) to its active metabolite enalaprilat. Further, it has been reported that the small intestines of both rat and human contain mainly CES2. The objective of this work was to understand whether enalapril remains unchanged as it is absorbed through the intestine into the portal circulation. This was evaluated using different intestinal preparations, an in situ intestinal perfusion experiment and a portal vein cannulated rat model. No turnover of enalapril was seen with commercial rat intestinal S9 and microsomes, but reasonable turnover was observed with freshly prepared rat intestinal and mucosal homogenate and S9. In the intestinal perfusion study, both enalapril and enalaprilat were observed in the mesenteric plasma with the data suggesting 32% hydrolysis of enalapril in the intestine. In the portal vein cannulated rat, about 51% of enalapril absorbed into intestine was converted to enalaprilat. Overall, it was demonstrated that even though enalapril has been shown to be a specific substrate for CES1, it is converted to enalaprilat to a significant extent in the intestine. Such experimental techniques can be applied by other scientific groups who are working on prodrugs to determine the region and extent of activation. Copyright © 2015 John Wiley & Sons, Ltd.
Impact of sampling time deviations on the prediction of the area under the curve using regression limited sampling strategies
Authors: Sarem Sarem , Nekka Fahima , Ahmed Iman Saad , Litalien Catherine , Li Jun
Published: April 2015

The regression limited sampling strategy approach (R‐LSS), which is based on a small number of blood samples drawn at selected time points, has been used as an alternative method for the estimation of the area under the concentration–time curve (AUC). However, deviations from planned sampling times may affect the performance of R‐LSS, influencing related therapeutic decisions and outcomes. The aim of this study was to investigate the impact of different sampling time deviation (STD) scenarios on the estimation of AUC by the R‐LSS using a simulation approach. Three types of scenarios were considered going from the simplest case of fixed deviations, to random deviations and then to a more realistic case where deviations of mixed nature can occur. In addition, the sensitivity of the R‐LSS to STD in each involved sampling point was evaluated. A significant impact of STD on the performance of R‐LSS was demonstrated. The tolerance of R‐LSS to STD was found to depend not only on the number of sampling points but more importantly on the duration of the sampling process. Sensitivity analysis showed that sampling points at which rapid concentration changes occur were relatively more critical for AUC prediction by R‐LSS. As a practical approach, nomograms were proposed, where the expected predictive performance of R‐LSS was provided as a function of STD information. The investigation of STD impact on the predictive performance of R‐LSS is a critical element and should be routinely performed to guide R‐LSS selection and use. Copyright © 2015 John Wiley & Sons, Ltd.
Metabolic engineering of an industrial polyoxin producer for the targeted overproduction of designer nucleoside antibiotics
Authors: Qi Jianzhao , Liu Jin , Wan Dan , Cai You‐sheng , Wang Yinghu , Li Shunying , Wu Pan , Feng Xuan , Qiu Guofu , Yang Sheng‐ping , Chen Wenqing , Deng Zixin
Published: April 2015

Polyoxin and nikkomycin are naturally occurring peptidyl nucleoside antibiotics with potent antifungal bioactivity. Both exhibit similar structural features, having a nucleoside skeleton and one or two peptidyl moieties. Combining the refactoring of the polyoxin producer Streptomyces aureochromogenes with import of the hydroxypyridylhomothreonine pathway of nikkomycin allows the targeted production of three designer nucleoside antibiotics designated as nikkoxin E, F, and G. These structures were determined by NMR and/or high resolution mass spectrometry. Remarkably, the introduction of an extra copy of the nikS gene encoding an ATP‐dependent ligase significantly enhanced the production of the designer antibiotics. Moreover, all three nikkoxins displayed improved bioactivity against several pathogenic fungi as compared with the naturally‐occurring antibiotics. These data provide a feasible model for high efficiency generation of nucleoside antibiotics related to polyoxins and nikkomycins in a polyoxin cell factory via synthetic biology strategy. Biotechnol. Bioeng. 2015;112: 1865–1871. © 2015 Wiley Periodicals, Inc.
An LC‐MS/MS method for determination of calceorioside B with cardiomyocyte protective activity in rat plasma and application to a pharmacokinetic study
Authors: Yang Fan , Song Yanqing , Zhang Sixi , Zhou Wei
Published: April 2015

A simple, sensitive and rapid liquid chromatography–tandem mass spectrometry (LC‐MS/MS) method was developed and validated for the determination of calceorioside B (CLB) in rat plasma. Detection was performed on a Thermo Scientific Hypersil Gold chromatography column using isocratic elution with a mobile phase of methanol–5 m m ammonium acetate–formic acid (70:30:0.1, v/v/v). Mass spectrometry was performed in selection reaction monitoring mode using a positive electrospray ionization interface. Good linearity was found for CLB in plasma in the linear range of 1.00–500 ng/mL (r > 0.9960). The validated method was successfully applied to the pharmacokinetic study of CLB in rats. Copyright © 2015 John Wiley & Sons, Ltd.
Generic Raman‐based calibration models enabling real‐time monitoring of cell culture bioreactors
Authors: Mehdizadeh Hamidreza , Lauri David , Karry Krizia M. , Moshgbar Mojgan , Procopio‐Melino Renee , Drapeau Denis
Published: April 2015

Raman‐based multivariate calibration models have been developed for real‐time in situ monitoring of multiple process parameters within cell culture bioreactors. Developed models are generic, in the sense that they are applicable to various products, media, and cell lines based on Chinese Hamster Ovarian (CHO) host cells, and are scalable to large pilot and manufacturing scales. Several batches using different CHO‐based cell lines and corresponding proprietary media and process conditions have been used to generate calibration datasets, and models have been validated using independent datasets from separate batch runs. All models have been validated to be generic and capable of predicting process parameters with acceptable accuracy. The developed models allow monitoring multiple key bioprocess metabolic variables, and hence can be utilized as an important enabling tool for Quality by Design approaches which are strongly supported by the U.S. Food and Drug Administration. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1004–1013, 2015
Evaluating the interaction between UCOE and DHFR‐linked amplification and stability of recombinant protein expression
Authors: Betts Zeynep , Croxford Alexandra S , Dickson Alan J
Published: April 2015

Chinese hamster ovary (CHO) cells are widely used in the biopharmaceutical industry. In the creation of mammalian cell lines plasmid DNA carrying the gene‐of‐interest integrates randomly into the host cell genome, which results in variable levels of gene expression between cell lines due to gene silencing mechanisms. In addition, cell lines often show unstable protein production during long‐term culture. This means that a large number of clones need to be screened in order to isolate stable, high producing cell lines making mammalian cell line development a long and laborious process. In this study an expression platform incorporating a Ubiquitous Chromatin Opening Element (UCOE; which are proposed to maintain chromatin in an open state) has been utilised for the expression of eGFP in CHO cells. Cell lines containing a UCOE vector, showed a significantly higher and more consistent eGFP expression than the non‐UCOE cell lines without DHFR amplification. To further improve recombinant protein production cell lines were amplified with methotrexate (MTX). UCOE cell lines showed improved growth in MTX therefore amplification to 250 nM MTX was achieved following a one‐step amplification procedure. However, non‐UCOE cell lines showed higher levels of eGFP production following MTX amplification. In addition, UCOE cell lines did not improve stability during long‐term culture in the absence of selective pressure. Stable eGFP production was achieved for all cell lines when MTX is present. Finally, UCOE cell lines displayed more consistent response to external stimuli than non‐UCOE cell lines, suggesting that UCOE cell lines are less prone to clonal variability. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1014–1025, 2015
Fischer‐Tropsch‐Synthese unter instationären Bedingungen im Suspensionsreaktor: experimentelle und rechnerische Studien
Authors: Eilers Hilko , Schaub Georg
Published: April 2015

Die Einbindung von Elektrolyse‐H2 aus erneuerbarer Elektrizität (Wind, solar) in die Erzeugung flüssiger Kohlenwasserstoff‐Energieträger kann zu einer Übertragung des fluktuierenden Charakters erneuerbarer Energien auf den chemischen Prozess führen. Mithilfe eines mathematischen Modells werden Sprungversuche in einer Laborapparatur ausgewertet, um Informationen über das Katalysatorverhalten unter instationären Bedingungen zu gewinnen. Erste Ergebnisse deuten darauf hin, dass die unter stationären Bedingungen ermittelte Reaktionskinetik ausreicht, um Übergänge im Reaktor zu beschreiben.
Pb(II) Adsorption Onto a Magnetic Composite of Activated Carbon and Superparamagnetic Fe3O4 Nanoparticles: Experimental and Modeling Study
Authors: Kakavandi Babak , Kalantary Roshanak R. , Jafari Ahmad J. , Nasseri Simin , Ameri Ahmad , Esrafili Ali , Azari Ali
Published: April 2015

Magnetic separation technology has been extensively used in the field of environmental problems, due to solving difficulties resulted from filtration and centrifuging. In this study, powder activated carbon (PAC) was magnetized by magnetite nanoparticles (Fe3O4@C) as an adsorbent for lead ions (Pb2+) from aqueous solution. The characteristics of the modified PAC were analyzed by scanning electron microscopy, transmission electron microscopy, X‐ray diffractometry, Brunauer‐Emmett‐Teller surface area analysis, energy dispersive X‐ray spectroscopy, and vibrating sample magnetometry. Batch adsorption experiments were conducted as a function of pH, contact time, adsorbent dosage and initial Pb2+ concentration, and solution temperature. The equilibrium isotherm and kinetic models were used to evaluate the fitness of the experimental data. The maximum mono‐layer adsorption capacity of Pb2+ was 71.42 mg/g at 50°C. It could also be shown that the sorption isotherms were well described by the Langmuir equilibrium model. The kinetic of the adsorption process was found to follow the pseudo‐second‐order model expression. Thermodynamic studies indicated that the adsorption process was feasible, spontaneous, and endothermic. Desorption experiments exhibited that the Fe3O4@C had a good potential in regard to regeneration and reusability and is easily regenerated by HCl solution. The proposed adsorption process can be a promising technique for Pb2+ removal from aqueous solutions and to be used in full‐scale and industrial applications.
Nerve growth factor promotes reorganization of the axonal microtubule array at sites of axon collateral branching
Authors: Ketschek Andrea , Jones Steven , Spillane Mirela , Korobova Farida , Svitkina Tatyana , Gallo Gianluca
Published: April 2015

The localized debundling of the axonal microtubule array and the entry of microtubules into axonal filopodia are two defining features of collateral branching. We report that nerve growth factor (NGF), a branch‐inducing signal, increases the frequency of microtubule debundling along the axon shaft of chicken embryonic sensory neurons. Sites of debundling correlate strongly with the localized targeting of microtubules into filopodia. Platinum replica electron microscopy suggests physical interactions between debundled microtubules and axonal actin filaments. However, as evidenced by depolymerization of actin filaments and inhibition of myosin II, actomyosin force generation does not promote debundling. In contrast, loss of actin filaments or inhibition of myosin II activity promotes debundling, indicating that axonal actomyosin forces suppress debundling. MAP1B is a microtubule associated protein that represses axon branching. Following treatment with NGF, microtubules penetrating filopodia during the early stages of branching exhibited lower levels of associated MAP1B. NGF increased and decreased the levels of MAP1B phosphorylated at a GSK‐3β site (pMAP1B) along the axon shaft and within axonal filopodia, respectively. The levels of MAP1B and pMAP1B were not altered at sites of debundling, relative to the rest of the axon. Unlike the previously determined effects of NGF on the axonal actin cytoskeleton, the effects of NGF on microtubule debundling were not affected by inhibition of protein synthesis. Collectively, these data indicate that NGF promotes localized axonal microtubule debundling, that actomyosin forces antagonize microtubule debundling, and that NGF regulates pMAP1B in axonal filopodia during the early stages of collateral branch formation. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 75: 1441–1461, 2015
Preexisting antigen‐specific immune responses are modulated by oral KLH feeding in humans
Authors: Hostmann Arwed , Meyer Tim , Maul Jochen , Preiss Jan , Boortz Bertram , Thiel Andreas , Duchmann Rainer , Ullrich Reiner
Published: April 2015

Oral tolerance is the antigen‐specific inhibition of a systemic immune response after oral antigen uptake and well established in animal models. We recently showed that keyhole limpet hemocyanin (KLH) feeding modulates subsequently induced systemic immune responses in humans as well. In the present study, we investigated whether oral KLH can also modulate preexisting antigen‐specific systemic B‐ and T‐cell responses. We induced delayed‐type hypersensitivity (DTH) reactions as well as systemic KLH‐specific B‐ and T‐cell responses by subcutaneous KLH injections. Subsequent oral KLH administration decreased the small proportion of antigen‐specific CD4+ T cells positive for the cytokine IL‐17 at the end of the feeding regimen even further. After reimmunization, there was no difference in DTH reactions and the KLH‐specific B‐cell responses, but KLH‐fed volunteers had an increased proportion of antigen‐specific CD4+ T cells positive for IL‐10 and a reduced proportion of antigen‐specific CD4+ T cells positive for the skin‐homing receptor cutaneous lymphocyte antigen and IL‐2 and IFN‐γ. Taken together, oral KLH can modulate a preexisting systemic KLH‐specific immune response. These results suggest that feeding antigen may offer therapeutic strategies for the suppression of unwanted immune reactions in humans.
The Electrically Wired Molybdenum Domain of Human Sulfite Oxidase is Bioelectrocatalytically Active
Authors: Spricigo Roberto , Leimkühler Silke , Gorton Lo , Scheller Frieder W. , Wollenberger Ulla
Published: April 2015

We report electron transfer between the catalytic molybdenum cofactor (Moco) domain of human sulfite oxidase (hSO) and electrodes through a poly(vinylpyridine)‐bound [osmium(N,N′‐methyl‐2,2′‐biimidazole)3]2+/3+ complex as the electron‐transfer mediator. The biocatalyst was immobilized in this low‐potential redox polymer on a carbon electrode. Upon the addition of sulfite to the immobilized separate Moco domain, the generation of a significant catalytic current demonstrated that the catalytic center is effectively wired and active. The bioelectrocatalytic current of the wired separate catalytic domain reached 25 % of the signal of the wired full molybdoheme enzyme hSO, in which the heme b5 is involved in the electron‐transfer pathway. This is the first report on a catalytically active wired molybdenum cofactor domain. The formal potential of this electrochemical mediator is between the potentials of the two cofactors of hSO, and as hSO can occupy several conformations in the polymer matrix, it is imaginable that electron transfer from the catalytic site to the electrode through the osmium center occurs for the hSO molecules in which the Moco domain is sufficiently accessible. The observation of catalytic oxidation currents at low potentials is favorable for applications in bioelectronic devices.
Synthesis, Structure, and Reactivity of Ruthenium(0) Indane Complexes fac‐[Ru(NCMe)3(CO)2(InX3)] (X = Cl, Br)
Authors: Itazaki Masumi , Ito Masaki , Nakazawa Hiroshi
Published: April 2015

The first ruthenium indane complexes, fac‐[Ru(NCMe)3(CO)2(InX3)] (X = Cl: 1, Br: 2), were synthesized in the reaction of triruthenium dodecacarbonyl Ru3(CO)12 with 3 equiv. of InX3 in acetonitrile at 80 °C for 30 min. Reaction of fac‐[Ru(NCMe)3(CO)2(InX3)] (X = Cl: 1, Br: 2) with PPh3 at a 1:1 molar ratio in acetonitrile at 50 °C for 5 h afforded cis,cis,trans‐[Ru(NCMe)2(CO)2(InX3)(PPh3)] (X = Cl: 3, Br: 4). The structures of 1–4 were determined by using single‐crystal X‐ray analysis.
Antioxidant capacity is a surrogate measure of the quality and stability of vegetable oils
Authors: Castelo‐Branco Vanessa Naciuk , Santana Isabelle , Di‐Sarli Vanessa Oliveira , Freitas Suely Pereira , Torres Alexandre Guedes
Published: April 2015

Total antioxidant capacity (TAC) may be a comprehensive oil quality index because of its potential association with chemical composition, oxidative stability, and fresh oil quality. We aimed to investigate the chemical determinants of the oxidative stability and TAC of oils using multivariate statistical analyses and the use of the TAC assay as a predictor of oil stability. Fatty acids, tocols, phenolic compounds, peroxide value, acid value, induction period (by the Rancimat test) and TAC (by the TEAC assay) were determined in refined canola, corn, soybean, and sunflower oils as well as cold‐pressed nut oils. Principal component analysis was used for data reduction and variable extraction. Generalized linear models successfully estimated the TAC (R2 = 90.3%, p < 0.005) and oxidative stability (R2 = 91.6%, p < 0.001) of the oils, and γ‐tocopherol was the most important predictor in both of the models. The peroxide value and induction period were linearly associated with antioxidant capacity (R2 = 0.65, p < 0.01 and R2 = 0.70, p < 0.01, respectively), allowing the prediction of the initial quality and oxidative stability of the oils by the TEAC assay. Additionally, the proposed minimum TAC value for good quality refined oils was 2.2 mmol TE/kg.

Practical Applications: Lipid oxidation is one of the major causes of vegetable oil degradation, affecting its global quality and limiting its shelf life. Therefore, a quality index applicable for estimating oxidative stability and initial quality of refined and cold‐pressed vegetable oils might be an important tool for quality control of oils in the food industry. We show that the TEAC assay, a simple and rapid spectrophotometric assay of antioxidant capacity, may be a useful tool for the determination of the global quality of oils due to its significant associations with the induction period and peroxide value. A minimum TAC value is advisable for good quality refined plant oils, especially when the initial quality and the shelf life are of concern.

Antioxidant capacity is a surrogate measure of the quality and stability of vegetable oils. 2.2 mmol trolox equivalents/kg was proposed as a minimum total antioxidant capacity value for good quality refined oils.
Co‐spray‐drying of a heme iron ingredient to decrease its pro‐oxidant effect in lipid‐containing foods
Authors: Alemán Mercedes , Bou Ricard , Polo Javier , Rodríguez Carmen , Tres Alba , Codony Rafael , Guardiola Francesc
Published: April 2015

Fortification of food products with non‐heme or heme iron is a common strategy to overcome nutritional iron deficiency. Heme iron is highly bioavailable but it promotes oxidation, as do other iron forms. Palm oil is widely used in the formulation of bakery products and chocolate fillings. The work reported here aims to delay the onset of oxidation of a palm oil matrix fortified with heme iron, as a model for bakery products, through the use of ascorbyl palmitate (0 and 400 mg/kg) and the co‐spray‐drying of the heme iron with calcium caseinate in two ratios (heme iron concentrate:caseinate, 2:1 and 1:1, w/w). Primary (peroxide value and lipid hydroperoxide content) and secondary (p‐anisidine value and hexanal content) oxidation were measured over one year of storage at room temperature in the dark. The combination of ascorbyl palmitate at 400 mg/kg and the co‐spray‐dried heme iron in a 1:1 ratio was the treatment that best protected iron fortified samples from oxidation during the storage time.

Practical applications: Food fortification with iron has been suggested as a good strategy for overcoming iron deficiency. In this study, a heme iron ingredient has been selected due to its higher bioavailability than inorganic iron forms. Nevertheless, as other iron forms, heme iron is a potent pro‐oxidant, which may affect the nutritional value, the sensory properties and shelf life of the fortified product. Thus, in this study the co‐spray‐drying of the heme iron with several coatings was assessed in order to reduce its pro‐oxidant activity. The different heme irons were mixed with palm oil, which is a fat widely used in bakery. The combination of co‐spray‐dried heme iron and ascorbyl palmitate delayed the onset of oxidation, which demonstrates its effectiveness in future iron fortified bakery products.

Palm oil is widely used in the formulation of bakery products and chocolate fillings. Therefore, this matrix can be a useful model for iron fortification in bakery products. In a preliminary study with heme iron fortified sunflower oil, the co‐spray‐drying of heme iron with different coating agents delayed the oxidation onset during accelerated storage at 60°C (see the figure).The combination of ascorbyl palmitate and the co‐spray‐drying of heme iron with calcium caseinate at 1:1 ratio (CAS 1:1) prevented oxidation of a heme iron fortified palm oil during storage at room temperature in the dark for one year.
Whey protein hydrolysates reduce autoxidation in microencapsulated long chain polyunsaturated fatty acids
Authors: Tamm Frederic , Gies Katharina , Diekmann Sabrina , Serfert Yvonne , Strunskus Thomas , Brodkorb André , Drusch Stephan
Published: April 2015

The aim of the present study was to investigate the ability of partially hydrolysed whey proteins to microencapsulate fish oil. Microcapsules were produced by spray‐drying emulsions composed of fish oil, glucose syrup (DE38) and β‐lactoglobulin or hydrolysates thereof prepared using bovine trypsin or alcalase. Hydrolysis did not negatively affect encapsulation performance during spray‐drying and microencapsulation efficiency was very high for all samples (99 ± 0.5%). However, enzymatic hydrolysis resulted in reduced formation of lipid hydroperoxides for all hydrolysate‐stabilised microcapsules, except for the hydrolysate produced by alcalase (3% degree of hydrolysis). Hydrolysis by trypsin resulted in a more narrow molecular weight peptide profile and an increased accessibility of antioxidant amino acids.

Practical applications: Whey proteins, a by‐product of the cheese industry, possess excellent nutritional properties, but have limited functional and antioxidant properties in their native form. Partial enzymatic hydrolysis can significantly enhance these properties. This study showed the excellent suitability of whey protein hydrolysates as emulsifiers in spray‐dried emulsions, which can improve encapsulation capacity and stabilisation of sensitive ingredients.

Partially enzymatically hydrolysed whey proteins serving as emulsifiers can increase the oxidative stability of microencapsulated polyunsaturated fatty acids.