bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rücken‐WNT für die Primärachse der Tiere
Authors: Hassel Monika 
Published: August 2016

AbstractViele Daten deuten auf eine frühe, einseitig regionalisierte Nutzung des WNT/β‐Catenin‐Signalwegs im letzten gemeinsamen Vorfahren der Cnidaria und Bilateria hin. Der morphologische Kopf der Cnidaria entspricht dabei dem Hinterende der Bilateria. Anneliden setzen das WNT/β‐Catenin‐System für frühe, lokale binäre Entscheidungen ein, und Insekten schlugen mit der Bicoid (Drosophila) – oder Hunchback/Orthodenticle (Tribolium) – basierten Achsenbildung einen Sonderweg ein. Dennoch ist das WNT‐System für alle Insekten während der Segmentierungsphase essenziell und bei ursprünglicheren Insekten und anderen Arthropoden ist WNT für die Bildung posteriorer Strukturen notwendig. Das WNT/β‐Catenin‐System ist damit ein essenzieller Bestandteil des Werkzeugkastens, der die Alleinstellungsmerkmale der Tiere begründete.
Streptomyceten
Authors: Schrempf Hildgund , Cypionka Heribert , Keller Ullrich 
Published: August 2016

AbstractStreptomyceten wurden 2016 von der VAAM zur Mikrobe des Jahres gewählt. Diese Bakterien zeichnen sich durch einen sehr differenzierten Lebenszyklus und ihre enorme genetische Vielfalt aus. In verschiedenen Boden‐Typen dominieren sie, dort sind sie Recycling‐Experten von Biopolymeren und in Folge essenziell für die Bildung von wertvollem Humus. Ihre Meisterleistungen liefern ein fast unerschöpfliches Repertoire von niedermolekularen chemischen Verbindungen. Von diesen werden zahlreiche zur Bekämpfung von Infektionskrankheiten und zur Behandlung von Tumoren therapeutisch einsetzt.
Torfmooskulturen als Ersatzlebensraum
Authors: Gaudig Greta , Krebs Matthias 
Published: August 2016

AbstractIn Deutschland sind 99 % der 1,4 Mio. Hektar Moore infolge von entwässerungsbasierter Nutzung degradiert und setzen enorme Mengen Treibhausgase frei. Die nasse Nutzung von Mooren (= Paludikultur) führt hingegen nicht nur zur Reduktion der Treibhausgasemissionen, sondern bietet zahlreiche weitere Vorteile für den Umwelt‐ und Naturschutz bei gleichzeitiger Biomassenutzung. Feldversuche zeigen den Mehrwert von Torfmooskulturen für die Biodiversität. Nach der Ernte der oberen Torfmoosrasenschicht wird die Biomasse aufbereitet und stofflich als Torfersatz in gärtnerischen Substraten verwendet. Torfmooskultivierung ist eine vielversprechende, nachhaltige Nutzungsalternative für degradierte Hochmoore.
Auf dem Weg zum Minimalgenom
Authors: Sander Johannes 
Published: August 2016

AbstractZiel der Synthetischen Biologie ist es, Organismen nach Maß im Computer zu designen und dann auch in der Realität zu konstruieren. Dazu wird zunächst eine Zelle mit Minimalgenom benötigt, die dann beliebig ausgebaut werden kann. Craig Venter ist es mit seiner Arbeitsgruppe gelungen, aus Mycoplasma mycoides einen selbstständig lebensfähigen Organismus mit nur 473 Genen zu erzeugen.
DNA‐Replikation bei Eukaryoten
Authors: Kronberg Inge 
Published: August 2016

AbstractOhne eine vorausgehende identische Verdopplung der genetischen Information können Zellen sich nicht teilen. Die DNA‐Replikation verläuft prinzipiell nach dem von Watson und Crick schon 1953 propagierten Schema, wonach sich die beiden Stränge der DNA‐Doppelhelix gabelförmig trennen und passende Nukleotide anlagern. Im Detail ist der Ablauf jedoch deutlich komplizierter, das gilt insbesondere für den Anfang und das Ende der Replikation in eukaryotischen Zellen. Hier geben hochauflösende kryo‐elektronenmikroskopische Bilder inzwischen genaueren Aufschluss.
Damit kann man rechnen
Authors: Hauk Andrea 
Published: August 2016

AbstractKönnen Sie sich noch an Ihre erste Rechnung im Labor erinnern? Ich schon. Es hat mich damals eine gefühlte Ewigkeit gekostet, die gewünschte Verdünnung aus einer konzentrierten Lösung herzustellen. Machen Sie es sich und Ihren Azubis leicht und nutzen Sie ein paar Mathe‐Tricks. Das erleichtert den Alltag.
Arterial hypertension: A neglected risk for bleeding
Authors: Vogel Birgit , Mehran Roxana 
Published: August 2016

Key points

The impact of arterial hypertension, one of the most common comorbidities in CAD patients, on bleeding risk after PCI must not be underestimated.
More rigorous control of blood pressure during PCI procedure, radial artery access and alternative anticoagulant strategy may be considered in these patients.
Further investigation in a more contemporary setting of PCI procedure is warranted.
Egg provoked food protein‐induced enterocolitis‐like syndrome in an adult
Authors: Zubrinich Celia , Hew Mark , O'Hehir Robyn 
Published: August 2016

Key Clinical MessageFood protein‐induced enterocolitis syndrome is a non‐IgE‐mediated food allergy usually diagnosed in infancy. We report a case of a similar syndrome in an adult, following ingestion of egg. We remind clinicians to consider this diagnosis which may present to emergency physicians and gastroenterologists long before an allergist is consulted.
Synthetic and Organocatalytic Studies of Quinidine Analogues with Ring‐Size Modifications in the Quinuclidine Moiety
Authors: Breman Arjen C. , van der Heijden Gydo , van Maarseveen Jan H. , Ingemann Steen , Hiemstra Henk 
Published: August 2016

AbstractSix highly enantiopure analogues of [2.2.2] were synthesized with five‐ or seven‐membered rings in the (original) quinuclidine skeleton. Five of these compounds were prepared through epoxide opening by a secondary cyclic amine, providing the nor‐ and homoquinuclidine moieties through five‐ and six‐membered ring formation. This method failed in the case of seven‐membered ring formation, so for that particular ring size a different synthetic route starting from 3‐quinuclidone was applied. The six novel analogues were examined as organocatalysts in four asymmetric conjugate addition reactions and the results compared with those of known cinchona alkaloid catalysts. This study shows that modification of the quinuclidine ring can have a substantial influence on catalyst activity and enantioselectivity. To acquire more insight into the characteristics of the new catalysts, the pKaH values were determined by means of fluorescence spectroscopy. Furthermore, relative reaction rates of conjugate thiol additions reactions catalyzed by these quinidine analogues were measured through polarimetry.
Van der Waals: erstmals gemessen
Authors: Feil Sylvia 
Published: August 2016

AbstractBei Kondensationen oder Aggregation wirken die zwar schwachen, doch in ihrer Summe maßgeblichen Van‐der‐Waals‐Kräfte. Sie treten bei der Adsorption wie auch der Reibung auf und können die Phasenbildung von atomaren wie molekularen Stoffen beeinflussen. Gleichwohl wurden sie bislang noch nie direkt gemessen, sondern nur vorhergesagt.
Optimization of bioreactor operating conditions using computational fluid dynamics techniques
Authors: Koerich Daniela M. , Rosa Leonardo M. 
Published: August 2016

AbstractHigh hydraulic retention times are commonly used in bioreactors, as they provide greater contact time between substrate and biomass. These reactors also operate at low flow rates to minimize damage to the biomass due to shear stress and drag. However, a high flow rate provides greater mixing, and thus the optimal operation condition is difficult to estimate. In this study, the effect of different flow rates on the behaviour of the phases in an anaerobic sequencing batch bioreactor is evaluated numerically. Fluent 15 code was used, considering the two‐phase, transient, and turbulent flow in a three‐dimensional mesh. The turbulence, the drag of the biomass flocs to the recirculation system, and the shear stress in the remaining solids were evaluated. For the reactor evaluated in this study, the flow rate of 189.4 g/s was found to be the most suitable, not only for the operation of the reactor, but also to provide energy savings in the operation of the recirculation pump.
Impact of salinity on warm water‐based mineable oil sands processing
Authors: Chen Tong , Lin Feng , Primkulov Bauyrzhan , He Lin , Xu Zhenghe 
Published: August 2016

AbstractContinuous use of caustics and increased level of water recycling inevitably increase the salinity of process water, which is a growing challenge in the current warm water‐based bitumen extraction process. The current study aims at understanding how salinity of process water affects bitumen recovery from mineable oil sands ores. Laboratory flotation results showed an ore‐dependent effect of salinity on bitumen recovery and froth quality. Processing of low‐grade ores suffered a dramatic loss in bitumen recovery with increasing NaCl up to 4000 ppm (i.e. 1574 ppm Na+) at pH 8.5, while only a marginal effect of salinity was found on the processability of a high‐grade ore. The use of caustics as a conventional approach to increase bitumen recovery and froth quality of poor processing ores showed a more severe negative impact of salinity on the processability of low‐grade ores. Salt addition was found to be detrimental to bitumen liberation and bitumen‐bubble attachment in the presence of fines, more so at higher pH of processing water. Increasing salt concentration in solution led to a significant decrease in the magnitude of negative zeta potentials for both bitumen and fine solids. These findings provide scientific guidance to searching for remediation strategies other than using caustics. Such an approach studied was the blending of low‐grade ores with high‐grade ores to minimize the negative impact of increased salinity in recycle water on bitumen extraction.
Application of mass balance models in the process of ozone removal of naphthenic acids from water
Authors: Al jibouri Ali Kamel H. , Wu Jiangning , Upreti Simant Ranjan 
Published: August 2016

AbstractThe oil sands process‐affected water (OSPW), produced in large amounts during the extraction of crude oil from oil sands, is toxic mainly due to the presence of naphthenic acids (NAs), among other constituents. Ozonation is an effective method for the removal of NAs. To provide information for better control of NAs ozonation, models based on mass balance were developed in this study to predict the concentration profiles of commercial NAs, dissolved ozone, and gaseous ozone during the process. It was found that the developed models successfully predicted the concentrations of commercial NAs and gaseous ozone. For the dissolved ozone concentration, the developed model can predict the equilibrium concentrations well. However, the actual ozone consumption was higher than that predicted by the model at the initial period of the ozonation process. This deviation possibly resulted from the inapplicability of the gas‐liquid equilibrium conditions at the initial high rate stage of the reaction. In addition, the Henry's law constant and the overall mass transfer coefficient for the given system were determined experimentally. Also investigated in this study was the effects of inlet gaseous ozone concentration into the reactor on the removal of NAs and on the concentration of dissolved ozone. As expected, the increase in inlet ozone concentration enhanced the removal of NAs and increased the concentration of dissolved ozone.
Distinct migratory behaviors of striosome and matrix cells underlying the mosaic formation in the developing striatum
Authors: Hagimoto Kazuya , Takami Saki , Murakami Fujio , Tanabe Yasuto 
Published: August 2016

ABSTRACTThe striatum, the largest nucleus of the basal ganglia controlling motor and cognitive functions, can be characterized by a labyrinthine mosaic organization of striosome/matrix compartments. It is unclear how striosome/matrix mosaic formation is spatially and temporally controlled at the cellular level during striatal development. Here, by combining in vivo electroporation and brain slice cultures, we set up a prospective experimental system in which we differentially labeled striosome and matrix cells from the time of birth and followed their distributions and migratory behaviors. Our results showed that, at an initial stage of striosome/matrix mosaic formation, striosome cells were mostly stationary, whereas matrix cells actively migrated in multiple directions regardless of the presence of striosome cells. The mostly stationary striosome cells were still able to associate to form patchy clusters via attractive interactions. Our results suggest that the restricted migratory capability of striosome cells may allow them to cluster together only when they happen to be located in close proximity to each other and are not separated by actively migrating matrix cells. The way in which the mutidirectionally migrating matrix cells intermingle with the mostly stationary striosome cells may therefore determine the topographic features of striosomes. At later stages, the actively migrating matrix cells began to repulse the patchy clusters of striosomes, presumably enhancing the striosome cluster formation and the segregation and eventual formation of dichotomous homogeneous striosome/matrix compartments. Overall, our study reveals temporally distinct migratory behaviors of striosome/matrix cells, which may underlie the sequential steps of mosaic formation in the developing striatum. J. Comp. Neurol. 525:794–817, 2017. © 2016 Wiley Periodicals, Inc.
Data assimilation for identification of cardiovascular network characteristics
Authors: Lal Rajnesh , Mohammadi Bijan , Nicoud Franck 
Published: August 2016

SummaryA method to estimate the hemodynamics parameters of a network of vessels using an Ensemble Kalman filter is presented. The elastic moduli (Young's modulus) of blood vessels and the terminal boundary parameters are estimated as the solution of an inverse problem. Two synthetic test cases and a configuration where experimental data are available are presented. The sensitivity analysis confirms that the proposed method is quite robust even with a few numbers of observations. The simulations with the estimated parameters recovers target pressure or flow rate waveforms at given specific locations, improving the state‐of‐the‐art predictions available in the literature. This shows the effectiveness and efficiency of both the parameter estimation algorithm and the blood flow model.
Modeling of light propagation in the human neck for diagnoses of thyroid cancers by diffuse optical tomography
Authors: Fujii H. , Yamada Y. , Kobayashi K. , Watanabe M. , Hoshi Y. 
Published: August 2016

AbstractDiffuse optical tomography using near‐infrared light in a wavelength range from 700 to 1000 nm has the potential to enable non‐invasive diagnoses of thyroid cancers; some of which are difficult to detect by conventional methods such as ultrasound tomography. Diffuse optical tomography needs to be based on a physically accurate model of light propagation in the neck, because it reconstructs tomographic images of the optical properties in the human neck by inverse analysis. Our objective here was to investigate the effects of three factors on light propagation in the neck using the 2D time‐dependent radiative transfer equation: (1) the presence of the trachea, (2) the refractive‐index mismatch at the trachea‐tissue interface, and (3) the effect of neck organs other than the trachea (spine, spinal cord, and blood vessels). There was a significant influence of reflection and refraction at the trachea‐tissue interface on the light intensities in the region between the trachea and the front of the neck surface. Organs other than the trachea showed little effect on the light intensities measured at the front of the neck surface although these organs affected the light intensities locally. These results indicated the necessity of modeling the refractive‐index mismatch at the trachea‐tissue interface and the possibility of modeling other neck organs simply as a homogeneous medium when the source and detectors were far from large blood vessels.
Facile Synthesis of NixZn1−xFe2O4 (x=0, 0.25, 0.5, 0.75, 1) as Anode Materials for Lithium Storage
Authors: Li Linlin , Jin Bo , Lang Xingyou , Yang Chuncheng , Gao Wang , Zhu Yongfu , Dou Shixue , Jiang Qing 
Published: August 2016

AbstractNixZn1−xFe2O4 (x=0, 0.25, 0.5, 0.75, 1) compounds were prepared by a hydrothermal method and subsequent heat treatment. The physical characteristics of the samples were investigated by field‐emission SEM, XRD, X‐ray photoelectron spectroscopy, and TEM. The electrochemical properties of NixZn1−xFe2O4 (x=0, 0.25, 0.5, 0.75, 1) as anode materials were tested for lithium‐ion batteries. The lithium‐storage properties of the electrodes were assessed by cyclic voltammetry and galvanostatic cycling. Among the five samples, Ni0.25Zn0.75Fe2O4 shows good electrochemical performance with a discharge capacity of 1488 mAh g−1 in the initial cycle and 856 mAh g−1 after 100 cycles.
Using multiple tracers and directly accounting for trophic modification improves dietary mixing‐model performance
Authors: Brett M. T. , Eisenlord M. E. , Galloway A. W. E. 
Published: August 2016

AbstractStable isotope (SI) mixing models are one of the most common approaches used to infer resource pathways in consumers. However, SI‐based analyses are often underdetermined, and consumer SI fractionation is often unknown. The use of fatty acid (FA) biomarkers in mixing models offers an alternative approach that can resolve the underdetermined constraint. A limitation to both methods is the considerable uncertainty regarding the “trophic modification” of dietary tracers, which occurs when consumers transform dietary resources into their own tissues. We tested the utility of SI and FA approaches for inferring the diets of the marine benthic isopod (Idotea wosnesenskii) fed various marine macroalgae in controlled feeding trials. Our analyses quantified how the accuracy and precision of Bayesian mixing models were influenced by the choice of algorithm (SIAR vs. MixSIR), trophic modification (assumed or known), and whether the model was under or overdetermined (seven sources and two vs. 26 tracers) for cases where isopods were fed an exclusive diet of one of the seven macroalgae. Using the conventional approach (two SI with assumed trophic modification) resulted in average model outputs, that is, the contribution from the exclusive resource =0.20 ± 0.23 (0.00–0.79), mean ± SD (95% credible interval), that only differed slightly from the prior assumption. This result was only somewhat improved by the use of measured trophic modification values for SI data. Using the FA‐based approach with known trophic modification greatly improved model performance, that is, the contribution from the exclusive resource =0.91 ± 0.10 (0.58–0.99). The choice of algorithm (SIAR vs. MixSIR) made a clear difference when trophic modification was known, and the model was overdetermined. In this case, SIAR and MixSIR had outputs of 0.86 ± 0.11 (0.48–0.96) and 0.96 ± 0.05 (0.79–1.00), respectively. When using FA biomarkers, going from two to seven tracers dramatically improved model performance (i.e., from 0.55 to 0.89, respectively), whereas going from 13 to 26 tracers only improved performance by 0.01. This analysis shows the choice and number of dietary tracers and the trophic modification assumption greatly influence the performance of mixing‐model dietary reconstructions and ultimately our understanding of what resources actually support aquatic consumers.
Simultaneous production of 1,3‐propanediol and n‐butanol by Clostridium pasteurianum: In situ gas stripping and cellular metabolism
Authors: Groeger Christin , Sabra Wael , Zeng An‐Ping 
Published: August 2016

Clostridium pasteurianum is a promising producer of the bulk chemicals 1,3‐propanediol and n‐butanol (BuOH), with significantly different product patterns and physiology from other typical Clostridia. Nevertheless, its growth and product formation are ultimately limited by the accumulation of inhibiting products, especially by BuOH. In this study, we implemented in situ gas stripping for BuOH removal and compared the stripping performance of external nitrogen (N2) and fermentation effluent gas (FG) from the process itself. Gas stripping was studied in fermentations of glycerol and a mixture of glycerol and glucose. In general, N2 exhibits favourable physical properties to strip out BuOH from an aqueous phase. However, in situ removal of butanol in C. pasteurianum culture with N2 stripping strongly perturbs the culture conditions such as the redox potential and thus the physiology of the microorganism, leading to enhanced formation of organic acids, especially in cosubstrate fermentation, whereas the use of FG does not show such perturbations. In an effort to explore the use of FG for gas stripping the effects of FG circulation rate and stirring speed of the bioreactor on BuOH stripping efficiency and the fermentation performance were studied in more detail. Mass transfer coefficient (kSa) of BuOH in the bioreactor was also characterized at different gas circulation rates and stirring speeds. In a fermentation of glycerol with FG stripping at a relatively high gas flow rate (7 vvm) as high as 39.2 g/L BuOH (total) and 53.7 g/L 1,3‐PDO can be simultaneously produced. The results are discussed in view of further process optimization and scale up.
Aromatic Hydrocarbon Production from Eucalyptus urophylla Pyrolysis over Several Metal‐Modified ZSM‐5 Catalysts
Authors: Schultz Emerson L. , Mullen Charles A. , Boateng Akwasi A. 
Published: August 2016

AbstractMetal‐modified HZSM‐5 catalysts were prepared by the ion exchange of NH4ZSM‐5 (SiO2/Al2O3=23) using Zn, Ga, Ni, and combinations thereof. The prepared catalysts were used to evaluate catalytic pyrolysis for the conversion of Eucalyptus urophylla to fuels and chemicals, specifically aromatic hydrocarbons, by using a micro‐scale pyrolysis reactor coupled with GC–MS. Two different biomass‐to‐catalyst ratios (1:5 and 1:10 w/w) were studied. The catalyst prepared with Ga by total ion exchange (Ga‐HZSM‐5 B, ≈7 wt % Ga) yielded the highest amount of aromatic hydrocarbons, whereas the catalysts modified with Ni produced the lowest yield of aromatic hydrocarbons. A correlation between the methane yield and benzene and p‐xylene selectivity was found for the catalysts, which was observed mainly for the Ni‐, Zn‐, and Ga‐Ni‐modified catalysts. The Ga‐modified catalysts were the most selective for xylenes, whereas the Ni‐based catalysts were the most selective for benzene production with a concurrent increase in methane production. The Zn‐modified catalysts were the most selective for toluene production.
High‐Performance Supercapacitor Electrode Materials from Chitosan via Hydrothermal Carbonization and Potassium Hydroxide Activation
Authors: Zhu Linfeng , Shen Feng , Smith Richard L. , Qi Xinhua 
Published: August 2016

AbstractNitrogen‐rich porous carbonaceous materials suitable for supercapacitor applications can be synthesized directly from chitosan using a hydrothermal treatment (250 °C, 14 h) that is followed by chemical activation of the carbonized solids with KOH (ca. 800 °C, 2 h). The synthesized chitosan‐derived carbonaceous materials (CDCMs) had high specific surface area (ca. 2200 m2 g−1), large pore volume (ca. 1.36 cm3 g−1), and high nitrogen content (ca. 6.3 %). When a current density of 0.5 A g−1 was applied to CDCM‐800 obtained at an activation temperature of 800 °C, specific capacitances of 231 and 305 F g−1 were achieved for 0.5 m K2SO4 and 6 m KOH aqueous electrolytes, respectively. Capacitances of 154 and 198 F g−1 were retained for the respective electrolytes at 20 Ag−1. CDCM‐800 had an energy density of 8.5 Wh kg−1 corresponding to a specific power of 1 kW kg−1 at 20 A g−1 in 6 m KOH aqueous electrolytes. The prepared carbonaceous materials retained 99 % of their properties for over 3000 cycles at 1 A g−1 in 0.5 m K2SO4. The nitrogen‐rich nanoporous carbonaceous materials have wide application in energy, electrical, chemical, analytic, separation, and catalysis.