bluuebunny/crossref_metadata_2025_split huggingface dataset:
A framework to quantify karyotype variation associated with CHO cell line instability at a single‐cell level
Authors: Baik Jong Youn , Lee Kelvin H. 
Published: December 2016

ABSTRACTChinese hamster ovary (CHO) cells, the major mammalian host cells for biomanufacturing of therapeutic proteins, have been extensively investigated to enhance productivity and product quality. However, cell line instability resulting in unexpected changes in productivity or product quality continues to be a challenge. Based on previous reports about causes and characteristics of production instability, we hypothesized that chromosomal rearrangements due to genomic instability are associated with production instability and that these events can be characterized. We developed a production instability model using secreted alkaline phosphatase (SEAP)‐expressing CHO cells (CHO‐SEAP) as well as a framework to quantify chromosomal rearrangements by karyotyping. In the absence of methotrexate (MTX), CHO‐SEAP cells exhibited a slightly increased growth rate, a significantly decreased specific productivity, and changes in the chromosomal rearrangement ratio of seven chromosomes. In contrast, when MTX was re‐introduced, the growth rate and SEAP productivity reversed to the initial values, demonstrating the reversibility of production instability in CHO‐SEAP cells. Fluorescence in situ hybridization analysis identified that the SEAP genes were incorporated in the chromosomal rearrangement (insertion) part of the der(Z9) chromosome. Karyotype analysis indicated that the insertion ratio of the der(Z9) chromosome decreased in the CHO‐SEAP cells grown without MTX, demonstrating a correlation between chromosomal rearrangement and production instability. Our results support a mechanism for production instability, wherein a randomly generated chromosomal rearrangement (or genotype) results in cells with a growth advantage that is also associated with non (or low)‐producing traits. As a result, the non‐producing cells grow faster and thereby outgrow the producing population. Biotechnol. Bioeng. 2017;114: 1045–1053. © 2016 Wiley Periodicals, Inc.
Facile Synthesis of Pd@Pt3–4L Core–Shell Octahedra with a Clean Surface and Thus Enhanced Activity toward Oxygen Reduction
Authors: Bao Shixiong , Vara Madeline , Yang Xuan , Zhou Shan , Figueroa‐Cosme Legna , Park Jinho , Luo Ming , Xie Zhaoxiong , Xia Younan 
Published: December 2016

AbstractThe presence of a capping agent or stabilizer in the synthesis of colloidal metal nanocrystals will compromise their performance if employed as electrocatalysts. Herein we demonstrate the synthesis of Pd@Pt3–4L core–shell octahedral nanocrystals with greatly enhanced activity toward the oxygen reduction reaction by eliminating the use of any capping agent or stabilizer. This was achieved by employing Pd octahedral seeds with well‐defined {1 1 1} facets and by dispersing them on a carbon black support prior to Pt deposition. Upon optimization of the reaction conditions, Pt ultrathin shells could be conformally deposited on the Pd octahedral seeds in a layer‐by‐layer fashion without involving self‐nucleation or island growth for the Pt atoms. The as‐obtained octahedral Pd@Pt3–4L/C catalyst exhibited a specific activity 50 % greater than that of a reference sample prepared in the presence of a polymer stabilizer such as poly(vinyl pyrrolidone). The polymer‐free catalyst also showed 5‐fold enhancement in specific activity if benchmarked against a commercial Pt/C catalyst.
Proton Exchange Membrane Fuel Cell with a Pt‐free Cathode and a Freely Diffusing Electron Acceptor
Authors: Thimmappa Ravikumar , Kottaichamy Alagar Raja , Devendrachari Mruthyunjayachari Chattanahalli , Aralekallu Shambulinga , Shafi Shahid Pottachola , Gautam Manu , Kotresh Harish Makri Nimbegondi , Thotiyl Musthafa Ottakam 
Published: December 2016

AbstractIn a fuel cell, almost 80% efficiency loss arises due to the cathode; consequently, the cathode requires the largest amount of precious metal catalyst. Here, we show a precious‐metal‐free cathode for a proton exchange membrane fuel cell (PEMFC) containing only carbon nanoparticles as the catalyst and a freely diffusing molecule as the electron acceptor. Factors controlling the true rate of electrochemical reactions are amplified just by using carbon nanoparticles, leading to a carbon corrosion‐free PEMFC delivering 154 mW/cm2 at 358 mA/cm2 without any precious metals.
Magnetic Anisotropy in Pentacoordinate NiII and CoII Complexes: Unraveling Electronic and Geometrical Contributions
Authors: Cahier Benjamin , Perfetti Mauro , Zakhia Georges , Naoufal Daoud , El‐Khatib Fatima , Guillot Régis , Rivière Eric , Sessoli Roberta , Barra Anne‐Laure , Guihéry Nathalie , Mallah Talal 
Published: December 2016

AbstractThe magnetic properties of the pentacoordinate [MII(Me4cyclam)N3]+ (Me4cyclam=tetramethylcyclam; N3=azido; M=Ni, Co) complexes were investigated. Magnetization and EPR studies indicate that they have an easy plane of magnetization with axial anisotropy parameters D close to 22 and greater than 30 cm−1 for the Ni and Co complexes, respectively. Ab initio calculations reproduced the experimental values of the zero‐field splitting parameters and allowed the orientation of the anisotropy tensor axes with respect to the molecular frame to be determined. For M=Ni, the principal anisotropy axis lies along the Ni−Nazido direction perpendicular to the Ni(Me4cyclam) mean plane, whereas for M=Co it lies in the Co(Me4cyclam) mean plane and thus perpendicular to the Co−Nazido direction. These orientations match one of the possible solutions experimentally provided by single‐crystal cantilever torque magnetometry. To rationalize the geometry and its impact on the orientation of the anisotropy tensor axis, calculations were carried out on model complexes [NiII(NCH)5]2+ and [CoII(NCH)5]2+ by varying the geometry between square pyramidal and trigonal bipyramidal. The geometry of the complexes was found to be the result of a compromise between the electronic configuration of the metal ion and the structure‐orienting effect of the Me4cyclam macrocycle. Moreover, the orientation of the anisotropy axes is mainly dependent on the geometry of the complexes.
A Fluorescence‐Lifetime‐Based Binding Assay for Class IIa Histone Deacetylases
Authors: Meyners Christian , Mertens Monique , Wessig Pablo , Meyer‐Almes Franz‐Josef 
Published: December 2016

AbstractClass IIa histone deacetylases (HDACs) show extremely low enzymatic activity and no commonly accepted endogenous substrate is known today. Increasing evidence suggests that these enzymes exert their effect rather through molecular recognition of acetylated proteins and recruiting other proteins like HDAC3 to the desired target location. Accordingly, class IIa HDACs like bromodomains have been suggested to act as “Readers” of acetyl marks, whereas enzymatically active HDACs of class I or IIb are called “Erasers” to highlight their capability to remove acetyl groups from acetylated histones or other proteins. Small‐molecule ligands of class IIa histone deacetylases (HDACs) have gained tremendous attention during the last decade and have been suggested as pharmaceutical targets in several indication areas such as cancer, Huntington's disease and muscular atrophy. Up to now, only enzyme activity assays with artificial chemically activated trifluoroacetylated substrates are in use for the identification and characterization of new active compounds against class IIa HDACs. Here, we describe the first binding assay for this class of HDAC enzymes that involves a simple mix‐and‐measure procedure and an extraordinarily robust fluorescence lifetime readout based on [1,3]dioxolo[4,5‐f]benzodioxole‐based ligand probes. The principle of the assay is generic and can also be transferred to class I HDAC8.
A Metal–Organic Framework Impregnated with a Binary Ionic Liquid for Safe Proton Conduction above 100 °C
Authors: Sun Xiao‐Li , Deng Wei‐Hua , Chen Hui , Han Hong‐Liang , Taylor Jared M. , Wan Chong‐Qing , Xu Gang 
Published: December 2016

AbstractTo develop proton‐conducting materials under low‐humidity conditions and at moderate working temperature still remains challenging for fuel‐cell technology. Here, a new type of proton‐conducting material, EIMS‐HTFSA@MIL, which was prepared by impregnating the binary ionic liquid, EIMS‐HTFSA (EIMS=1‐(1‐ethyl‐3‐imidazolium)propane‐3‐sulfonate; HTFSA=N,N‐bis(trifluoromethanesulfonyl)amide), into a mesoporous metal–organic framework, MIL‐101 ([Cr3F(H2O)2O(BDC)3⋅n H2O] (n≈0.25, BDC=1,4‐benzenedicarboxylate)) is reported. By taking advantage of the ionic‐liquid properties, such as high thermal stability, non‐volatility, non‐flammability, and low corrosivity, EIMS‐HTFSA@MIL shows potential application as a safe electrolyte in proton conduction above 100 °C.
Direct Access to Chiral β‐Fluoroamines with Quaternary Stereogenic Center through Cooperative Cation‐Binding Catalysis
Authors: Vaithiyanathan Venkataramasubramanian , Kim Mun Jong , Liu Yidong , Yan Hailong , Song Choong Eui 
Published: December 2016

AbstractA direct route to chiral β‐fluoroamines with tetrasubstituted C−F centers through the organocatalytic Mannich reaction of α‐fluoro cyclic ketones and α‐amidosulfones by using a chiral oligoethylene glycol as a cation‐binding catalyst and KF as a base is reported. For most substrates, nearly perfect enantioselectivities were achieved even at very high temperatures (>80 °C). The salient features of this process include a) a transition‐metal‐free and operationally simple procedure, b) direct use of α‐amidosulfones as bench‐stable precursors of sensitive imines, c) direct enolization of racemic α‐fluoro cyclic ketones, and d) excellent stereoselectivity up to 99 % enantiomeric excess and >20:1 diastereoselectivity (anti/syn). Thus, this protocol is easily scalable and provides a new approach for the synthesis of biologically relevant products with tetrasubstituted C−F centers. Furthermore, this protocol was also successfully extended to generate C−Cl and C−Br quaternary stereogenic centers.
Measurement of Fluid Dynamics in Random Packings Using High‐Resolution Computed Tomography
Authors: Schug Sebastian , Arlt Wolfgang 
Published: December 2016

AbstractDurch Aufnahme computertomographischer Bilder über die Höhe einer Füllkörperkolonne sind lokale und integrale Werte für den Holdup, die benetzte Füllkörperoberfläche und die Stoffaustauschfläche bestimmt worden. Hierfür sind der Raschig Super‐Ring, RMSR und Raflux‐Ring über einen weiten Betriebsbereich untersucht worden. Die Ergebnisse zeigen große Unterschiede zwischen den drei Füllkörpertypen und lassen sich aufgrund der hohen räumlichen Auflösung der Messtechnik quantifizieren. Die Resultate der integralen Werte sind weitgehend unabhängig von der Füllkörperschüttung und auch nach Neuschüttung der Füllkörper reproduzierbar.
Investigation of the minimum miscibility pressure for injection of two different gases into two Iranian oil reservoirs: Experimental and theory
Authors: Moosazadeh Mohammad , Keshavarzi Behnam , Ghotbi Cyrus 
Published: December 2016

AbstractThe results of the minimum miscibility pressure (MMP) determination for miscible injection of two gases (CO2 and an associated gas of one of Iranian gas reservoirs) into two different oil samples from two Iranian oil reservoirs using a slim tube apparatus are presented in this work. For efficient determination of MMP, prior to slim tube experimentation, cell‐to‐cell simulation of the slim tube experiment was performed using a tuned Peng Robinson equation of state as a pre‐experiment and the results were used as initial estimates of MMP to select the pressure steps for the slim tube experiment. Finally, a comparison between the measured MMP values obtained by the slim tube experiments and those calculated by cell‐to‐cell simulation was made. It was shown that the cell‐to‐cell slim tube simulation predicts the results of slim tube experiments with a relative error of less than 6 %. This low error value shows that cell‐to‐cell simulation can replace the slim tube test in the cases where time is a major concern. Moreover, since the slim tube is an expensive and time‐consuming experiment and selecting the pressures to run the test is very important, cell‐to‐cell simulation can help us select the pressures for performing a slim tube experiment.
How do ions enhance the transfer during nanofiltration of saccharides? Experimental assessment of the dehydration assumption
Authors: Boy Virginie , Roux‐de Balmann Hélène , Galier Sylvain 
Published: December 2016

AbstractThe aim of the work was to improve the understanding of the role of ion hydration on the transfer during nanofiltration of saccharides. More precisely, it consisted in evaluating the physical relevance of the dehydration assumption to explain the increased transfer of saccharides in presence of electrolytes. Experiments were carried out using saccharides (xylose, glucose) and electrolytes containing ions of different hydration levels (NaCl, Na2SO4). The Filmtec NF membrane (previously referred to as NF45) was used. Unlike saccharide/NaCl solutions, Na2SO4 had a weak influence on the saccharide transfer. This means that the impact of the electrolyte on the transfer of saccharide was strongly affected by the ions retention. Indeed, SO42‐ ions were much more often retained than Cl‐. Thus, an enhanced saccharide transfer was expected as the electrolyte concentration in the permeate was high. The physical relevance of the assumed dehydration was evaluated. The decrease of the saccharide radius was determined from the mass transfer modelling. It was shown that the decrease was physically relevant with the dehydration phenomenon since this decrease corresponded to a fraction of the water molecule (2–3 %). Next, the increased transfer was compared with the variation of the apparent molar volume, characterizing the hydration state of solutes, to better understand the mechanisms involved. For a given electrolyte, the transfer increased continuously with saccharide dehydration. This result could confirm that the increase of the transfer could be attributed to the saccharide dehydration caused by the electrolyte.
Numerical modelling and simulation of hydrogen production via four different chemical reforming processes: Process performance and energy requirements
Authors: Sánchez Rafael A. , Riboldi Luca , Jakobsen Hugo A. 
Published: December 2016

AbstractMethane reforming operated in fluidized bed reactors is modelled and simulated for four different chemical processes: Steam Methane Reforming (SMR) process and the both non‐commercially available Sorption‐Enhanced Steam Methane Reforming (SE‐SMR) process and Chemical Looping Reforming process for non‐autothermal (naCLR) as well as autothermal (aCLR) operation. These processes are operated at relevant operating conditions. The results from the reforming simulations are used as input in a Pressure Swing Adsorption model, where the hydrogen is further purified to about 99.99 % and delivered at 2500 kPa (25 bar) of pressure and 25 °C. The energy consumption for hydrogen production on a mole basis is calculated for each chemical process with and without heat recuperation, with heat recuperation referring in this context to the utilization of the thermal energy available from the cooling of certain fluid streams to power other parts of the process.
Origin of the Excellent Performance of Ru on Nitrogen‐Doped Carbon Nanofibers for CO2 Hydrogenation to CH4
Authors: Roldán Laura , Marco Yanila , García‐Bordejé Enrique 
Published: December 2016

AbstractCarbon materials have rarely been used as support for CO2 methanation, which is usually carried out using catalysts supported on metal oxides. Here, it is shown that Ru nanoparticles supported on nitrogen‐doped carbon nanofibers (NCNF) provide competitive CH4 production rate and stability compared to Al2O3‐supported catalysts. Contrary to the general belief about the inert nature of carbon supports, it is demonstrated that NCNF is a non‐innocent spectator in CO2 methanation due to its ability to store a high amount of COad reaction intermediates. This explains the excellent catalytic behaviour afforded by this unconventional catalyst support.
Aluminum‐Mediated Formation of Cyclic Carbonates: Benchmarking Catalytic Performance Metrics
Authors: Rintjema Jeroen , Kleij Arjan W. 
Published: December 2016

AbstractWe report a comparative study on the activity of a series of fifteen binary catalysts derived from various reported aluminum‐based complexes. A benchmarking of their initial rates in the coupling of various terminal and internal epoxides in the presence of three different nucleophilic additives was carried out, providing for the first time a useful comparison of activity metrics in the area of cyclic organic carbonate formation. These investigations provide a useful framework for how to realistically valorize relative reactivities and which features are important when considering the ideal operational window of each binary catalyst system.
Virtual cell imaging: A review on simulation methods employed in image cytometry
Authors: Ulman Vladimír , Svoboda David , Nykter Matti , Kozubek Michal , Ruusuvuori Pekka 
Published: December 2016

AbstractThe simulations of cells and microscope images thereof have been used to facilitate the development, selection, and validation of image analysis algorithms employed in cytometry as well as for modeling and understanding cell structure and dynamics beyond what is visible in the eyepiece. The simulation approaches vary from simple parametric models of specific cell components—especially shapes of cells and cell nuclei—to learning‐based synthesis and multi‐stage simulation models for complex scenes that simultaneously visualize multiple object types and incorporate various properties of the imaged objects and laws of image formation. This review covers advances in artificial digital cell generation at scales ranging from particles up to tissue synthesis and microscope image simulation methods, provides examples of the use of simulated images for various purposes ranging from subcellular object detection to cell tracking, and discusses how such simulators have been validated. Finally, the future possibilities and limitations of simulation‐based validation are considered. © 2016 International Society for Advancement of Cytometry
Formulation and characterization of food grade water‐in‐oil emulsions encapsulating mixture of essential amino acids
Authors: Bhatti Hamzah Shahbaz , Khalid Nauman , Uemura Kunihiko , Nakajima Mitsutoshi , Kobayashi Isao 
Published: December 2016

The present study was conducted to study the encapsulation properties of a mixture of four amino acids (AAs) in the disperse phase of water‐in‐oil (W/O) emulsions. Four different AAs (methionine, lysine, threonine, and tryptophan) at 1% (w/w) each AA concentration was used in dispersed phase, while the continuous phase constitutes vegetable oils with 5% (w/w) tetraglycerin monolaurate condensed ricinoleic acid esters as an emulsifier. The optimized conditions include homogenization at 7000 rpm for 5 min using soybean oil as a continuous phase medium. The average droplet diameter of the W/O emulsions ranged between 4 and 5 μm with a coefficient of variation between 20 and 23%. The W/O emulsions were found to be stable over a period of 30 days at 4°C with slight phase separation at 25°C after 30 days of storage. The W/O emulsions retain about 10.5 mg/mL (encapsulation efficiency 79.8%) of amino acids after 30 days of storage at 4 and 25°C. The methionine and lysine have encapsulation efficiency of over 80% in comparison to threonine (79%) and tryptophan (60%) after 30 days of storage at 4 and 25°C.Practical applications: Multiple studies have emphasized the benefits to human health of including amino acids in the diet and as special nutrient formula for sport persons. For this reason, the study was proposed to formulate a stable emulsion system that could later be able to formulate high energy food or energy drinks. The optimization of formulation parameters is necessary for industrial production and the methodology pointed in this research is far easily to apply and helps in designing new nutraceuticals and functional foods.Successful encapsulation of mixture of amino acids (methionine, lysine, threonine, and tryptophan) at (4% (w/w)) in the W/O emulsions. The W/O emulsions have encapsulation efficiency over 70% after 1 month of storage.
Encapsulation of cholecalciferol and ergocalciferol in oil‐in‐water emulsions by different homogenization techniques
Authors: Khalid Nauman , Kobayashi Isao , Neves Marcos A. , Uemura Kunihiko , Nakajima Mitsutoshi , Nabetani Hiroshi 
Published: December 2016

Ergocalciferol (VD2) and cholecalciferol (VD3) are bioactive compounds with reduced bioavailability. Soybean oil, olive oil, or medium chain triglyceride containing 0.5% w/w VD2 and VD3, was used as a dispersed phase, while phosphate buffer containing 1% w/w Tween 20 served as a continuous phase. The two phases were emulsified with a rotor‐stator homogenizer (RSH) at 5000–20 000 rpm for 5 min or with high pressure homogenization (HPH) at 100 MPa after RSH at 7000 rpm for 5 min. The volume mean diameter (d4,3) of the formulated oil‐in‐water (O/W) emulsions gradually decreased with increasing the rotation speed of RSH. The O/W emulsions formulated under appropriate homogenization conditions remained stable over 30 days of storage period. There was no prominent difference in d4,3 of the O/W emulsions formulated with the HPH, differing from d4,3 of the O/W emulsions formulated with the RSH during 30 days of storage period. There was little effect of homogenization types on release profile of the VD2 and VD3 loaded emulsions. The encapsulation efficiencies of VD2 and VD3 were less than 70% after 10 days of storage, followed by sharp decline to 10% after 30 days at 4°C.Practical applications: Multiple studies have emphasized the benefits to human health of including vitamins in the diet and as special nutrient formula for athletes. For this reason, our study was proposed to formulate a stable emulsion system that could later be added to formulate high energy food or energy drinks.A mixture of cholecalciferol (VD2) and ergocalciferol (VD3) is successfully encapsulated in the O/W emulsions. The different homogenization conditions have no significant effect on the encapsulation efficiencies. There is sharp decline in encapsulation efficiencies of VD2 and VD3 after 15 days of storage.
An intelligent bioreactor system for the cultivation of a bioartificial vascular graft
Authors: Maschhoff Paul , Heene Sebastian , Lavrentieva Antonina , Hentrop Thorleif , Leibold Christian , Wahalla Marc‐Nils , Stanislawski Nils , Blume Holger , Scheper Thomas , Blume Cornelia 
Published: December 2016

Cardiovascular disease is the most common cause of death, accounting for 31% of deaths worldwide. As purely synthetic grafts implicate concomitant anticoagulation and autologous veins are rare, tissue‐engineered vascular grafts are urgently needed. For successful in vitro cultivation of a bioartificial vascular graft, the suitable bioreactor should provide conditions comparable to vasculogenesis in the body. Such a system has been developed and characterized under continuous and pulsatile flow, and a variety of sensors has been integrated into the bioreactor to control parameters such as temperature, pressure up to 500 mbar, glucose up to 4.5 g/L, lactate, oxygen up to 150 mbar, and flow rate. Wireless data transfer (using the ZigBee specification based on the IEEE 802.15.4 standard) and multiple corresponding sensor signal processing platforms have been implemented as well. Ultrasound is used for touchless monitoring of the growing vascular structure as a quality control before implantation (maximally achieved ultrasound resolution 65 μm at 15 MHz). To withstand the harsh conditions of steam sterilization (120°C for 20 min), all electronics were encapsulated. With such a comprehensive physiologically conditioning, sensing, and imaging bioreactor system, all the requirements for a successful cultivation of vascular grafts are available now.