bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metallionenextraktion
Authors: Nitsch W. 
Published: September 2012

AbstractAn Beispielen aus dem eigenen Arbeitskreis wird ein Überblick gegeben über die Kinetik der Metallionenextraktion. Ausführlich behandelt wird die Überlagerung strömungsabhängiger Transportprozesse mit Grenzflächenreaktionen, die Aufstellung der zuständigen Modelle und deren experimentelle Überprüfung. Am Beispiel der gekoppelten Stoffübertragung von Salpetersäure und Uranylkationen in eine Tributylphosphat‐beladene Hexanphase wird das für mehrkomponentige Systeme typische Problem des Zuganges zu den Transport‐koeffizienten angeschnitten. Am gleichen System wird gezeigt, daß das kinetische Systemverhalten wegen der Anzahl der Gleichungen und deren Kopplung nur über numerische Verfahren beurteilt werden kann. Abschließend behandelt wird die Wirkung von Adsorptions‐schichten auf die Massenflüsse zwischen Flüssigphasen. Hingewiesen wird auf die entscheidenden Unterschiede, die sich bei einer Transportkinetik respektive einer Grenzflächenkinetik ergeben: Sind Transportprozesse geschwindigkeitsbestimmend, so bewirken Adsorbate eine Dämpfung der Strömung und damit der Transportkoeffizienten, im Falle einer Grenzflächenkinetik ist die Adsorbatwirkung eine Katalyse.
Über den Einfluß von Phasenverteilungen auf den Wirkungsgrad von Trennstufen
Authors: Schlünder E. U. 
Published: September 2012

AbstractTrennstufen, deren Wirkung auf dem Ausgleich von Gleichgewichtsstörungen beruhen, erreichen ihre maximale Trennleistung, wenn dieser Ausgleich vollständig abläuft. Tatsächlich beobachtet man stets einen unvollständigen Ausgleich. Als Ursache hierfür wird die endliche Diffusionsgeschwindigkeit der Komponenten in den beteiligten Phasen angesehen. ‐ Es wird gezeigt, daß ein unvollständiger Ausgleich auch allein durch eine mikroskopische Fehlordnung der beteiligten Phasen verursacht werden kann, ohne daß dabei die Gesetze der Diffusion eine Rolle spielen. Die Existenz solcher Fehlordnungen wird durch eine Analyse von Meßwerten an Füllkörperstufen nachgewiesen. ‐ Für weitere Nachweise dieser Art wird ein hierfür besonders geeignetes Experiment vorgeschlagen.
Zur Verwendung von Na‐Al‐Silikaten in Waschmitteln Teil VIII: Farbstoffgleichgewichte in Mehrkomponentensystemen
Authors: Nüßlein H. , Schumann K. , Schwuger M. J. 
Published: September 2012

AbstractHauptbestandteile des Wäscheschmutzes bilden ölige und fettige Anschmutzungen, Pigmente sowie lösliche und unlösliche Salze. Farbstoffe als Schmutz nehmen eine Sonderstellung speziell in industriellen Waschprozessen ein. Am Beispiel eines Substantivfarbstoffs wurde die Beeinflussung von Farbstoffgleichgewichten in Waschprozessen durch das klassische lösliche Hilfsmittel Polyvinylpyrrolidon (PVP) und die wasserunlösliche Wirksubstanz Na — Al‐Silikat (SASIL) untersucht. Während PVP im wäßrigen Medium den Farbstoff durch Komplexbildung stabilisiert, verhindert SASIL durch gezielte Abgabe von löslichen Bestandteilen, die mit Farbstoffen und Fasern in Wechselwirkung treten können, das Wiederaufziehen der Farbstoffe auf textile Oberflächen. Kolloidchemische Untersuchungen in Verbindung mit Modellwaschversuchen zeigen, daß beide Substanzen, trotz unterschiedlicher Wirkmechanismen, einen vergleichbaren Einfluß auf die Farbstoffgleichgewichte im wäßrigen Medium ausüben.
Temperature‐dependent hyperfine coupling constants. An ESR study of the N‐hydropyridinyl radical in solution
Authors: Sander Ulrich , Dohrmann Jürgen K. 
Published: September 2012

AbstractThe proton and nitrogen hyperfine splittings of the short‐lived N‐hydropyridinyl radical have been measured over the temperature range ‐80 to 42°C in Propanol(‐2)/Acetone. The ESR‐data of the N‐deuteropyridinyl and the N‐hydropentadeuteropyridinyl radical at 22°C have been determined. The temperature coefficient of the NH proton splitting and the shift in the splitting caused by N‐deuterium substitution are unusually large. The effects of temperature and deuterium substitution have been analyzed using the model of localized out‐of‐plane vibrations of the protons. The estimated frequencies, in units of cm−1, are 290, 490, and 870 for the protons in position 1, 3(5), and 4, respectively. The result is discussed in connection with other ESR and MO studies on N‐hydropyridinyl and N, N′‐dihydrodiazinyl radicals. The previously observed non‐transferability of the spin polarization parameter QHNH is explained by the exceptionally low vibration frequency of the NH proton. A value of QHNH = −3.1 ± 0.4 mT is derived for the fixed planar structure of the radical. The vibrational analysis also confirms the negative sign of the π‐spin density on the carbon atoms in position 3 and 5.
Pressure and temperature dependence of the longitudinal proton and deuteron relaxation rates in NH3 and ND3
Authors: Hauer H. , Lang E. , Lüdemann H.‐D. 
Published: September 2012

AbstractThe molecular mobility of liquid ammonia is derived from the determination of the longitudinal relaxation times of the protons and deuterons. The experiments were performed in the temperature interval between the melting pressure curve and 467 K for NH3 and to 351 K for ND3 at pressures up to 250 MPa. At temperatures below ∼ 350 K the molecular mobility can be described by the isotropic small‐step diffusion model. The activation energies at constant pressure are derived for the rotatoric diffusion to 7.0 ± 0.5 kJ · mol−1 and for the translatoric diffusion to 6 ± 1 kJ · mol−1 from the temperature dependence of the relaxation rates. In addition the activation energy at constant volume for the rotatoric diffusion has been determined to 5.7 ± 0.5 kJ · mol−1. The isotherms for all relaxation rates are linear in a log(1/T1) versus 1/T plot, yielding ΔV≠intra = 2.5 ± 0.6 cm3 · mol−1 and ΔV≠inter = 5 ± 1 cm3 · mol−1.
Identification of the gaseous molecules ZnS(g), ZnTe(g), CdTe(g), and HgSe(g) in equilibrium with the solid phase
Authors: Grade M. , Hirschwald W. 
Published: September 2012

AbstractBy means of high‐temperature mass‐spectrometry the gaseous IIB/VIA‐molecules ZnS(g), ZnTe(g), CdTe(g), and HgSe(g) were identified by their isotopic distributions in equilibrium with the corresponding solid chalcogenides. HgTe(g) remains the only MeX(g)‐molecule of the IIB/VIA‐type as yet undetected — suggesting that the remaining eleven IIB/VIA‐molecules may originate from a gas‐phase reaction between Me(g)‐ and Xi(g)‐species which cannot occur in the HgTe‐system due to the absence of gaseous Tei in the equilibrium vapor phase.
Numerical assessment of the performance of a scalp‐implantable antenna: Effects of head anatomy and dielectric parameters
Authors: Kiourti Asimina , Nikita Konstantina S. 
Published: September 2012

AbstractWe numerically assess the effects of head properties (anatomy and dielectric parameters) on the performance of a scalp‐implantable antenna for telemetry in the Medical Implant Communications Service band (402.0–405.0 MHz). Safety issues and performance (resonance, radiation) are analyzed for an experimentally validated implantable antenna (volume of 203.6 mm3), considering five head models (3‐ and 5‐layer spherical, 6‐, 10‐, and 13‐tissue anatomical) and seven scenarios (variations ± 20% in the reference permittivity and conductivity values). Simulations are carried out at 403.5 MHz using the finite‐difference time‐domain method. Anatomy of the head model around the implantation site is found to mainly affect antenna performance, whereas overall tissue anatomy and dielectric parameters are less significant. Compared to the reference dielectric parameter scenario within the 3‐layer spherical head, maximum variations of −19.9%, +3.7%, −55.1%, and −39.2% are computed in the maximum allowable net input power imposed by the IEEE Std C95.1‐1999 and Std C95.1‐2005 safety guidelines, return loss, and maximum far‐field gain, respectively. Compliance with the recent IEEE Std C95.1‐2005 is found to be almost insensitive to head properties, in contrast with IEEE Std C95.1‐1999. Taking tissue property uncertainties into account is highlighted as crucial for implantable antenna design and performance assessment. Bioelectromagnetics 34:167–179, 2013. © 2012 Wiley Periodicals, Inc.
Luminometer development in the last four decades: recollections of two entrepreneurs
Authors: Berthold Fritz , Tarkkanen Veikko 
Published: September 2012

ABSTRACTThis article, written by two entrepreneurs in luminescence, traces their involvement in the major part of the interconnected innovation and development of luminometers, adenosine triphosphate (ATP) bioluminescence and other technologies from the mid‐1970s to 2011 that ushered in much of the field of luminometry as we know it today. Key developments leading to current commercial applications of ATP bioluminescence, luminescence immunoassay, cellular luminescence, reporter gene and other applications are described from the first tube luminometers derived from early luminescence studies using liquid scintillation counting technology to measuring bioluminescence from crude ATP and firefly tail extracts. Copyright © 2012 John Wiley & Sons, Ltd.
Surface functionalization of carbon nanomaterials by self‐assembling hydrophobin proteins
Authors: Yang Wenrong , Ren Qin , Wu Ya‐Na , Morris Vanessa K. , Rey Anthony A. , Braet Filip , Kwan Ann H. , Sunde Margaret 
Published: September 2012

AbstractClass I fungal hydrophobins are small surface‐active proteins that self‐assemble to form amphipathic monolayers composed of amyloid‐like rodlets. The monolayers are extremely robust and can adsorb onto both hydrophobic and hydrophilic surfaces to reverse their wettability. This adherence is particularly strong for hydrophobic materials. In this report, we show that the class I hydrophobins EAS and HYD3 can self‐assemble to form a single‐molecule thick coating on a range of nanomaterials, including single‐walled carbon nanotubes (SWCNTs), graphene sheets, highly oriented pyrolytic graphite, and mica. Moreover, coating by class I hydrophobin results in a stable, dispersed preparation of SWCNTs in aqueous solutions. No cytotoxicity is detected when hydrophobin or hydrophobin‐coated SWCNTs are incubated with Caco‐2 cells in vitro. In addition, we are able to specifically introduce covalently linked chemical moieties to the hydrophilic side of the rodlet monolayer. Hence, class I hydrophobins provide a simple and effective strategy for controlling the surfaces of a range of materials at a molecular level and exhibit strong potential for biomedical applications. © 2012 Wiley Periodicals, Inc.
A 3D cell culture system: Separation distance between INS‐1 cell and endothelial cell monolayers co‐cultured in fibrin influences INS‐1 cells insulin secretion
Authors: Sabra Georges , Vermette Patrick 
Published: September 2012

AbstractThe aim of this study was to develop an in vitro cell culture system allowing studying the effect of separation distance between monolayers of rat insulinoma cells (INS‐1) and human umbilical vein endothelial cells (HUVEC) co‐cultured in fibrin over INS‐1 cell insulin secretion. For this purpose, a three‐dimensional (3D) cell culture chamber was designed, built using micro‐fabrication techniques and validated. The co‐culture was successfully carried out and the effect on INS‐1 cell insulin secretion was investigated. After 48 and 72 h, INS‐1 cells co‐cultured with HUVEC separated by a distance of 100 µm revealed enhanced insulin secretion compared to INS‐1 cells cultured alone or co‐cultured with HUVEC monolayers separated by a distance of 200 µm. These results illustrate the importance of the separation distance between two cell niches for cell culture design and the possibility to further enhance the endocrine function of beta cells when this factor is considered. Biotechnol. Bioeng. 2013; 110: 619–627. © 2012 Wiley Periodicals, Inc.
High density continuous production of murine pluripotent cells in an acoustic perfused bioreactor at different oxygen concentrations
Authors: Baptista Ricardo P. , Fluri David A. , Zandstra Peter W. 
Published: September 2012

AbstractStrategies for the production of pluripotent stem cells (PSCs) rely on serially dissociated adherent or aggregate‐based culture, consequently limiting robust scale‐up of cell production, on‐line control and optimization of culture conditions. We recently developed a method that enables continuous (non‐serially dissociated) suspension culture‐mediated reprogramming to pluripotency. Herein, we use this method to demonstrate the scalable production of PSCs and early derivatives using acoustic filter technology to enable continuous oxygen‐controlled perfusion culture. Cell densities of greater than 1 × 107 cells/mL were achieved after 7 days of expansion at a specific growth rate (µ) of 0.61 ± 0.1 day−1 with a perfusion rate (D) of 5.0 day−1. A twofold increase in maximum cell density (to greater than 2.5 × 107 cells/mL) was achieved when the medium dissolved oxygen was reduced (5% DO). Cell densities and viabilities >80% were maintained for extended production periods during which maintenance of pluripotency was confirmed by stable expression of pluripotency factors (SSEA‐1 and Nanog), as well as the capacity to differentiate into all three germ layers. This work establishes a versatile biotechnological platform for the production of pluripotent cells and derivatives in an integrated, scalable and intensified stirred suspension culture. Biotechnol. Bioeng. 2013; 110: 648–655. © 2012 Wiley Periodicals, Inc.
Anion exchange membrane adsorbers for flow‐through polishing steps: Part I. clearance of minute virus of mice
Authors: Weaver Justin , Husson Scott M. , Murphy Louise , Wickramasinghe S. Ranil 
Published: September 2012

AbstractMembrane adsorbers may be a viable alternative to the packed‐bed chromatography for clearance of virus, host cell proteins, DNA, and other trace impurities. However, incorporation of membrane adsorbers into manufacturing processes has been slow due to the significant cost associated with obtaining regulatory approval for changes to a manufacturing process. This study has investigated clearance of minute virus of mice (MVM), an 18–22 nm parvovirus recognized by the FDA as a model viral impurity. Virus clearance was obtained using three commercially available anion exchange membrane adsorbers: Sartobind Q®, Mustang Q®, and ChromaSorb®. Unlike earlier studies that have focused on a single or few operating conditions, the aim here was to determine the level of virus clearance under a range of operating conditions that could be encountered in industry. The effects of varying pH, NaCl concentration, flow rate, and other competing anionic species present in the feed were determined. The removal capacity of the Sartobind Q and Mustang Q products, which contain quaternary ammonium based ligands, is sensitive to feed conductivity and pH. At conductivities above about 20 mS/cm, a significant decrease in capacity is observed. The capacity of the ChromaSorb product, which contains primary amine based ligands, is much less affected by ionic strength. However the capacity for binding MVM is significantly reduced in the presence of phosphate ions. These differences may be explained in terms of secondary hydrogen bonding interactions that could occur with primary amine based ligands. Biotechnol. Bioeng. 2013; 110: 491–499. © 2012 Wiley Periodicals, Inc.
Peroxidase immobilized on phospholipid bilayers supported on au (111) by DTT self‐assembled monolayers: Application to dopamine determination
Authors: Fritzen‐Garcia Maurícia B. , Zoldan Vinícius C. , Oliveira Inês Rosane W.Z. , Soldi Valdir , Pasa André A. , Creczynski‐Pasa Tânia B. 
Published: September 2012

AbstractIn this work, horseradish peroxidase (HRP) was immobilized on dimyristoylphosphatidylcholine (DMPC) bilayers supported on Au (111) by dithiotreitol (DTT) self‐assembled monolayers and used as a nanostructured electrochemical biosensor to dopamine determination. The morphology of the phospholipid bilayers and the immobilization of HRP to these layers were characterized by atomic force microscopy (AFM). Square‐wave voltammetry (SWV) experiments were done to investigate the performance of the HRP‐modified electrode. The AFM images indicate that the enzyme is adsorbed at the external layer of the lipid bilayer and, although the electrical charges on the surface were not measured, the enzyme and phospholipids surface interaction occurs probably by electrostatic forces due to the pH used in the experiments. Interestingly, the present system can be used as one‐shot sensor for the rapid detection of dopamine. The analytical performance of this system was linear for dopamine concentrations from 3.3 × 10−5 to 1.3 × 10−3 mol L−1 (r = 0.9997) with a detection limit of 2.0 × 10−6 mol L−1. Our results indicate that the use of HRP‐DMPC bilayer system may be useful not only in developing new nanostructured materials for technological purposes, but could be very useful in fundamental studies to investigate the interactions between different micro‐and macromolecules, even with soluble proteins, and lipid membranes. Biotechnol. Bioeng. 2013; 110: 374–382. © 2012 Wiley Periodicals, Inc.
Enhanced production of Aspergillus niger laccase‐like multicopper oxidases through mRNA optimization of the glucoamylase expression system
Authors: Tamayo‐Ramos Juan Antonio , Barends Sharief , de Lange Dennis , de Jel Annemarie , Verhaert Raymond , de Graaff Leo 
Published: September 2012

AbstractIn filamentous fungi, most of the strategies used for the improvement of protein yields have been based on an increase in the transcript levels of a target gene. Strategies focusing at the translational level have been also described, but are far less explored. Here the 5′ untranslated sequence of the glaA mRNA, a widely used expression system for the expression of recombinant proteins, was modified by the introduction of different nucleotide elements that have positive role in the translation process. Five Aspergillus niger laccase‐like multicopper oxidases (MCOs) coding genes were fused to the native glaA 5′UTR and the three synthetic versions (sUTR1, sUTR2, and sUTR3) as well, and placed under the control of the glucoamylase gene promoter. Afterwards, a total of 20 fungal transformations were done using A. niger N593 as a recipient strain and 50 transformants per transformation were isolated and analyzed. The result of the incorporation of the synthetic 5′UTRs on the overall productivity of the transformants was assessed, on one hand by monitoring the laccase activity of all the isolated transformants, and on the other hand by quantifying and comparing the activity of those secreting the highest level of each MCO. For this purpose, a high‐throughput method for the screening and selection of the best producers was developed. Once the best transformants producing the highest yield of McoA, McoB, McoC, McoD, and McoJ laccases were selected, their production level was quantified in supernatants of liquid cultures. The results obtained in this work indicate that modifications in the native glaA 5′UTR can lead to improvements in protein yields. Biotechnol. Bioeng. 2013; 110: 543–551. © 2012 Wiley Periodicals, Inc.
Rare case of the trunk of the inferior phrenic arteries originating from a common stem with a superior additional left renal artery from the abdominal aorta
Authors: Miclaus Gratian D. , Matusz Petru , Loukas Marios , Ples Horia 
Published: September 2012

AbstractWe describe in this article a rare case of a 39‐year‐old male with an inferior phrenic arteries trunk (IPAaT) originating from a common stem with a superior additional left renal artery (SAdLRA) from the abdominal aorta as revealed by routine multidetector computed tomography angiography. The IPAaT with an endoluminal diameter at the origin of 2.8 mm had an upward path with a total length of 18.4 mm, forking to the right inferior phrenic artery and left inferior phrenic artery. These two arteries had an endoluminal diameter at the origin of 1.7 mm and 2.0 mm, respectively. The presence of the common stem of the IPAaT with a SAdLRA and the length of the IPAaT complicate selective chemoembolization of the liver parenchyma. Clin. Anat. 25:979–982, 2012. © 2012 Wiley Periodicals, Inc.
Microchannel Emulsification Using Stainless‐Steel Chips: Oil Droplet Generation Characteristics
Authors: Kobayashi I. , Wada Y. , Hori Y. , Neves M. A. , Uemura K. , Nakajima M. 
Published: September 2012

AbstractThe first stainless‐steel microchannel (MC) emulsification chips with grooved MC arrays, each consisting of uniform‐sized parallel channels and a terrace, were developed. These chips enabled successful spontaneous‐transformation‐based generation of uniformly sized droplets of soybean oil and silicone oil. As for the influence of the dispersed‐phase velocity in a channel, the critical velocity below which uniform‐sized droplets were obtained from the channels depended on the interfacial tension between two phases. The maximum productivity of uniform‐sized oil droplets for the stainless‐steel MC emulsification chips was estimated to be several milliliters per hour. An adapted capillary number that considers the wettability of the dispersed phase of two different oils could be useful for understanding the flow state of the dispersed phase during droplet generation.
Gas‐Liquid Mass Transfer Characteristics in a Rotating‐Drum Bioreactor
Authors: Zhang Q. , Wang Z. , Wen S. , Liu G. , Wu X. , Cong W. 
Published: September 2012

AbstractThe oxygen volumetric mass transfer coefficient is a key parameter to characterize the performance of aerobic bioreactors. A novel rotating‐drum bioreactor (RDB) fitted with a sparger as proposed in a previous work has demonstrated its excellent gas‐liquid mass transfer performance. To provide primary information on the design and scale‐up of the novel RDB, effects of reactor configuration including the number and width of lifters and operation conditions such as rotational speed, aeration rate, and solid volume fraction on mass transfer performance were systematically investigated in a new medium‐sized RDB. Compared with the stirred bioreactor and traditional RDBs, this new RDB exhibits better mass transfer performance. Taking both operational and reactor configuration parameters into consideration, an empirical correlation to predict the volumetric mass transfer coefficient in this type of RDBs was proposed which is valuable for its design and scale‐up.
Behavior of Pieces of Plastic Sheet in Solid‐Liquid Fluidized Bed with Stirring
Authors: Tatemoto Y. , Michikoshi T. , Higashino T. , Maeda S. , Maeda S. , Bando Y. 
Published: September 2012

AbstractA solid‐liquid fluidized bed of inert particles can be used to separate pure objects from a mixture. Pieces of plastic sheet were selected as the objects to be separated. To estimate the separation characteristics, the behavior of pieces of plastic sheet in the bed was examined experimentally. Slow stirring was used to improve the fluidization state of the bed. The object size and the volume ratio of objects to inert particles were varied. The use of stirring of the bed was effective in improving the fluidization state of the bed, and the objects, which sank in the bed without stirring, moved from the bottom to the upper portion of the bed at a certain liquid velocity. This liquid velocity increases with decreasing object size, and it also increases as the volume ratio of objects to inert particles in the bed increases. When the volume ratio of objects to inert particles is too high, the objects are distributed throughout the entire bed, regardless of the liquid velocity.