bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrating a 250 mL‐spinner flask with other stirred bench‐scale cell culture devices: A mass transfer perspective
Authors: Vallejos Jose R. , Brorson Kurt A. , Moreira Antonio R. , Rao Govind 
Published: February 2011

AbstractThe bioprocess development cycle is a complex task that requires a complete understanding of the engineering of the process (e.g., mass transfer, mixing, CO2 removal, process monitoring, and control) and its affect on cell biology and product quality. Despite their widespread use in bioprocess development, spinner flasks generally lack engineering characterization of critical physical parameters such as kLa, P/V, or mixing time. In this study, mass transfer characterization of a 250‐mL spinner flask using optical patch‐based sensors is presented. The results quantitatively show the effect of the impeller type, liquid filling volume, and agitation speed on the volumetric mass transfer coefficient (kLa) in a 250‐mL spinner flask, and how they can be manipulated to match mass transfer capability at large culture devices. Thus, process understanding in spinner flasks can be improved, and these devices can be seamlessly integrated in a rational scale‐up strategy from cell thawing to bench‐scale bioreactors (and beyond) in biomanufacturing. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011.
Effect of chemical chaperone addition on production and aggregation of recombinant flag‐tagged COMP‐angiopoietin 1 in chinese hamster ovary cells
Authors: Hwang Su‐Jeong , Jeon Choon‐Ju , Cho Sung Min , Lee Gyun Min , Yoon Sung Kwan 
Published: February 2011

AbstractTo investigate the effect of chemical chaperones on the production and aggregation of flag‐tagged cartilage oligomeric matrix protein‐Angiopoietin1 (FCA1) in recombinant Chinese hamster ovary (CHO) cells, CHO cells were cultivated in serum‐free media with various chemical chaperones, 1 mM 4‐phenylbutyrate (4‐PBA), 200 mM proline, 3% glycerol, 2% dimethyl sulfoxide (DMSO), and without chemical chaperone as control. The addition of chemical chaperones enhanced FCA1 production and specific FCA1 productivity, qFCA1. For example, the qFCA1 at 200 mM proline was fourfold higher than that at control. Unlike qFCA1, the aggregation of FCA1 was strongly affected by which chemical chaperone was added. The addition of 2% DMSO and 200 mM proline significantly reduced the proportion of aggregates, but the addition of 1 mM 4‐PBA and 3% glycerol was hardly effective. The proportions of aggregates were 29.5 and 55.6% at 2% DMSO and 200 mM proline, respectively, whereas it was 79.6% at control. The exact mechanism how chemical chaperones affected the aggregation of FCA1 was not investigated in this study, and therefore, more extensive works will be needed to clarify why different chemical chaperones behaved differently in reducing the aggregation of FCA1. Among chemical chaperones tested, DMSO was the most effective one in regard to enhancing the production and reducing the aggregation of FCA1 in CHO cells. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Peptide Mesocrystals as Templates to Create an Au Surface with Stronger Surface‐Enhanced Raman Spectroscopic Properties
Authors: Su Ying , He Qiang , Yan Xuehai , Fei Jinbo , Cui Yue , Li Junbai 
Published: February 2011

AbstractThe design and fabrication of various nanostructures with predefined geometry and composition is a big challenge of nanotechnology. Here we demonstrate an Au nanoflake film replicated from a self‐assembled, well‐ordered, dipeptide flower‐like hierarchical architecture. Such morphology can give rise to useful and remarkable surface‐enhanced Raman spectroscopy (SERS) properties. We obtained these nanostructures by using a scaffold of flake‐built spherical dipeptide aggregations. Gold nanoparticles were sputtered on the surface of as‐assembled dipeptide by an etching system. After removing the dipeptide templates by ethanol, a metal crust was left with a morphology similar to that of the dipeptide hierarchical structure. The different steps within the process were monitored by using electron microscopy, energy‐dispersive spectrum (EDS) analysis and atomic force microscopy (AFM). Cyclic voltammetry and Raman spectra were employed to prove the SERS effect of the obtained Au substrates. The enhancement factor is estimated to be about 104 for 4‐mercaptobenzoic acid (4‐MBA) molecules on the Au nanoflake surfaces.
Förster Energy Transfer Theory as Reflected in the Structures of Photosynthetic Light‐Harvesting Systems
Authors: Şener Melih , Strümpfer Johan , Hsin Jen , Chandler Danielle , Scheuring Simon , Hunter C. Neil , Schulten Klaus 
Published: February 2011

AbstractFörster′s theory of resonant energy transfer underlies a fundamental process in nature, namely the harvesting of sunlight by photosynthetic life forms. The theoretical framework developed by Förster and others describes how electronic excitation migrates in the photosynthetic apparatus of plants, algae, and bacteria from light absorbing pigments to reaction centers where light energy is utilized for the eventual conversion into chemical energy. The demand for highest possible efficiency of light harvesting appears to have shaped the evolution of photosynthetic species from bacteria to plants which, despite a great variation in architecture, display common structural themes founded on the quantum physics of energy transfer as described first by Förster. Herein, Förster’s theory of excitation transfer is summarized, including recent extensions, and the relevance of the theory to photosynthetic systems as evolved in purple bacteria, cyanobacteria, and plants is demonstrated. Förster′s energy transfer formula, as used widely today in many fields of science, is also derived.
From Sir2008 to Sir2011: the role of electron diffraction
Authors: Camalli M. , Carrozzini B. , Cascarano G. L. , Giacovazzo C. 
Published: February 2011

AbstractThe crystal structure solution of small‐medium size molecules via single crystal X‐ray data is almost a routine process. When single crystals of sufficient dimensions are not available, electron diffraction is a useful alternative: the structure solution however may still be a challenge. We have modified the standard version of Sir2008 to include several new tools, which are expected to make the phasing process more straightforward. Additional work is in progress: in Sir2011, the heir of Sir2008, particular emphasis will be given to a new procedure for the determination of the space groups, to a new approach (BEA) aiming at reducing in the practice the perverse effects of the dynamical scattering and to the simulated annealing algorithm, as a phasing tool particularly useful in case of organic structures, when scarce or poor experimental data are available. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of ion beam sputtered ZrN coatings prepared at different substrate temperatures
Authors: Larijani M. M. , Kiani M. , Tanhayi M. , Majdabadi A. 
Published: February 2011

AbstractZirconium nitride (ZrN) coatings were prepared on Si (100) by single ion beam sputtering in N2 and Ar mixture at different substrate temperatures. Structure and morphology of the ZrN coatings were analyzed using X‐ray diffraction and atomic force microscopy. Rutherford backscattering technique was utilized for the determination of composition and thickness of the coatings. Electrical properties of the ZrN coatings were determined by four point‐ probe and Hall test. The results showed that the growth of ZrN with a preferred (111) orientation was achieved. The coating thickness depended on the substrate temperature and coating surface roughly remained smooth. The resistivity of the coatings varied from 1× 10‐3 to 14× 10‐3 Ω cm depending on the substrate temperature. A correlation between resistivity and charge carrier density was established to explain the electrical behavior of the coatings. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficacy and safety of the PPARγ partial agonist balaglitazone compared with pioglitazone and placebo: a phase III, randomized, parallel‐group study in patients with type 2 diabetes on stable insulin therapy
Authors: Henriksen Kim , Byrjalsen Inger , Qvist Per , Beck‐Nielsen Henning , Hansen Gitte , Riis Bente J. , Perrild Hans , Svendsen Ole Lander , Gram Jeppe , Karsdal Morten A. , Christiansen Claus ,   for the BALLET trial investigators
Published: February 2011

AbstractBackgroundTreatment of patients with perioxisome proliferator‐activated receptor‐γ full agonists are associated with weight gain, heart failure, peripheral oedema, and bone loss. However, the safety of partial perioxisome proliferator‐activated receptor‐γ agonists has not been established in a clinical trial. The BALaglitazone glucose Lowering Efficacy Trial aimed to establish the glucose‐lowering effects and safety parameters of the perioxisome proliferator‐activated receptor‐γ partial agonist balaglitazone in diabetic patients on stable insulin therapy.MethodsFour hundred and nine subjects from three countries with type 2 diabetes on stable insulin therapy were randomized to 26 weeks of double‐blind treatment with once daily doses of 10 or 20 mg balaglitazone, 45 mg pioglitazone, or matching placebo (n ≥ 99 in each group). The primary endpoint was the efficacy of balaglitazone 10 and 20 mg versus placebo on the absolute change in haemoglobin A1c. Secondary endpoints included levels of fasting serum glucose, and changes in body composition and bone mineral density as measured by dual energy X‐ray absorptiometry, in comparison to pioglitazone 45 mg. This study is registered with Clinicaltrials.gov identifier: NCT00515632.ResultsIn the 10‐ and 20‐mg balaglitazone groups, and in the 45‐mg pioglitazone group, significant reductions in haemoglobin A1c levels were observed (−0.99, − 1.11, and − 1.22%, respectively; p < 0.0001) versus placebo. Fasting serum glucose was similarly reduced in all treatment arms. Dual energy X‐ray absorptiometry analyses showed that, while balaglitazone at 10 mg caused weight gain and fluid retention compared to placebo, the magnitude of these effects was significantly smaller than that of pioglitazone 45 mg and balaglitazone 20mg. Balaglitazone at either dose did not appear to reduce bone mineral density, while Pioglitazone showed a trend towards a reduction.ConclusionPatients treated with balaglitazone at 10 mg and 20 mg and pioglitazone at 45 mg showed clinically meaningful improvements in glucose levels and HbA1c. With the 10 mg dose, the benefits (glucose & HgA1c lowering) and untoward effects (fluid and fat accumulation) were less, results that encourage further studies of this drug candidate. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of retinoic acid and butyric acid on the expression of prestin and gata‐3 in organotypic cultures of the organ of corti of newborn rats
Authors: Gross Johann , Stute Kerstin , Fuchs Julia , Angerstein Maximilian , Amarjargal Nyamaa , Mazurek Birgit 
Published: February 2011

AbstractPrestin is the motor protein of the outer hair cells of the organ of Corti and a key factor in ensuring a high level of sensitivity of mammalian hearing. The factors that influence prestin expression are still largely unknown. We studied the effects of the application of retinoic acid, a ligand of a nuclear receptor, and of butyric acid, an inhibitor of histone deacetylase activity, on the expression of mRNA of prestin and Gata‐3 in the organotypic culture of the organ of Corti of newborn rats using RT‐PCR. Application of retinoic acid at concentrations of 1–50 μM results in a dose‐dependent expression decrease after two days in culture. Treatment with sodium butyrate (0.5–2 mM) elevated the expression of prestin and Gata‐3. Statistically significant correlations between Gata‐3 and prestin mRNA levels were observed under all conditions. The data indicate that retinoid nuclear transcription factors, GATA‐3 and histone acetylation/deacetylation processes may have a regulatory role to play in prestin expression. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 650–661, 2011
Differential weight restoration on olanzapine versus fluoxetine in identical twins with anorexia nervosa
Authors: Duvvuri Vikas , Cromley Taya , Klabunde Megan , Boutelle Kerri , Kaye Walter H. 
Published: February 2011

AbstractObjective:No studies have compared the response to selective serotonin reuptake inhibitors and atypical antipsychotics in anorexia nervosa. This case study examines such a comparison.Method:This report describes a case of 12‐year‐old identical twins with anorexia nervosa, one of whom was treated with olanzapine and the other with fluoxetine, while undergoing family therapy.Results:Twin A treated with fluoxetine went from 75 to 84.4% ideal body weight, while Twin B treated with olanzapine went from 72 to 99.9% ideal body weight over the course of 9 months.Discussion:This case supports the need for adequately powered, controlled clinical trials to test the efficacy of olanzapine in adolescents presenting with anorexia nervosa. © 2011 by Wiley Periodicals, Inc. (Int J Eat Disord 2012)
Electric field‐induced self‐assembly of micro‐ and nanoparticles of various shapes at two‐fluid interfaces
Authors: Janjua Muhammad , Nudurupati Sai , Singh Pushpendra , Aubry Nadine 
Published: February 2011

AbstractParticle lithography which explores the capability of particles to self‐assemble offers an attractive means to manufacture nanostructured materials. Although traditional techniques typically lead to the formation of dense crystals, adjustable non‐close‐packed crystals are crucial in a number of applications. We have recently proposed a novel method to assemble spherical micro‐ and nanoparticles into monolayers. The technique consists of trapping particles at a liquid–fluid interface and applying an electric field normal to the interface. Particles rearrange themselves under the influence of interfacial and electrostatic forces to form 2‐D hexagonal arrays of long‐range order and whose lattice constant depends on the electric field strength and frequency. Furthermore, the existence of an electric field‐induced capillary force makes the technique applicable to submicron and nanosized particles. Although spherical particles are often used, non‐spherical particles can be beneficial in practice. Here, we review the method, discuss its applicability to particles of various shapes, and present results for particles self‐assembly on air–liquid and liquid–liquid interfaces. In the case of non‐spherical particles, the self‐assembly process, while still taking place, is more complex as particles experience a torque which causes them to rotate relative to one another. This leads to a final arrangement displaying either a dominant orientation or no well‐defined orientation. We also discuss the possibility of dislodging the particles from the interface by applying a strong electric field such that the Weber number is of order 1 or larger, a phenomenon which can be utilized to clean particles from liquid–fluid surfaces.
Insight into the mechanism of transient trapping in micellar electrokinetic chromatography
Authors: Breadmore Michael C. , Quirino Joselito P. , Thormann Wolfgang 
Published: February 2011

AbstractTransient trapping is a new mechanism of on‐line sample concentration and separation that has recently been presented. It involves the injection of a short length of micellar solution in front of the sample, making it similar to sweeping in partial‐filling MEKC. Here, we examine the mechanism of transient trapping by the use of computer simulations and compare it to sweeping in MEKC for the two analytes, sulforhodamine B and 101. The simulation results confirm the mechanism for concentration and separation originally proposed. The mechanism for concentration is similar to sweeping since the analytes are picked and accumulated by the micelles that penetrate the sample zone. The mechanism for separation is however quite unique since the concentrated analytes are trapped for a few seconds on the sample/micelle boundary before they are released as the concentration of micelle is reduced as it undergoes electromigration dispersion and the analytes separate down a micelle gradient. Simulation results suggested that a significant contribution of band broadening arises from the micelle gradient, with shallower gradients resulting in broader peaks. However, this is offset by an increase in selectivity, such that resolution was enhanced even though the peaks are broader. Transient trapping analysis with similar resolution to those obtained by sweeping MEKC could be achieved in 1/10 of the time and 1/4 of the capillary length, which results in a 2–3 times increase in sensitivity.
A simplified poly(dimethylsiloxane) capillary electrophoresis microchip integrated with a low‐noise contactless conductivity detector
Authors: Liu Benyan , Zhang Yi , Mayer Dirk , Krause Hans‐Joachim , Jin Qinghui , Zhao Jianlong , Offenhäusser Andreas 
Published: February 2011

AbstractA contactless conductivity detector integrated into a poly(dimethylsiloxane) microchip for electrophoresis is presented. It adopted the simplest configuration of electrodes commonly used in this detection mode for capillary electrophoresis microchips. Although the chip is based on a simple and effective design, it is able to obtain low detection levels due to the low noise of the detection circuit. A circuit based on a lock‐in amplifier was designed on printed circuit boards to read out the signal. The property of the detection cell was studied by applying excitation signals of different frequencies and different amplitudes. It was found that the best detection limit could be achieved with a frequency of 50 kHz and amplitude of 20 V. The performance of the detector was demonstrated by successfully separating and detecting several inorganic ions and also a mixture of heavy metal ions. An average detection limit of 0.4 μM was obtained for inorganic cations. This value is significantly improved compared to similar microchip‐based detectors. The presented detector could be promising for mass production due to its properties, such as simple construction, high degree of integration, high performance and low cost.
Optimizing the extraction, separation and quantification of tricyclic antidepressant drugs in human plasma with CE‐ESI‐TOF‐MS using cationic‐coated capillaries
Authors: Elhamili Anisa , Samuelsson Jörgen , Bergquist Jonas , Wetterhall Magnus 
Published: February 2011

AbstractIn this study, the extraction and CE‐ESI‐TOF‐MS analysis of tricyclic antidepressant (TCA) drugs imipramine, desipramine, clomipramine and norclomipramine in human plasma has been optimized. The CE capillaries were modified with ω‐iodo‐alkyl ammonium salt (M7C4I coating) to reduce analyte adsorption to the silica wall. The use of a strong cation exchange (SCX) solid‐phase extraction (SPE) column specifically designed for the extraction of basic drug species from biofluids gave very clean extracts with high and reproducible recoveries. The extraction recoveries were ranging between 87 and 91% with % RSD values of 0.5–1.7% (n=3). The obtained strong cation exchange‐SPE extracts of the TCA in human plasma only contained the analytes of interest. The optimized CE separation conditions were obtained by adding ACN and acetic acid to the sample while using an aqueous BGE. The CE‐ESI‐TOF‐MS analysis was performed within 6 min for all TCA analytes under the optimized condition with peak efficiencies up to 1.4×105 plates/m and an average % RSD of the migration times of the analytes of 0.3% (n=5). The presented method can readily be used for the extraction and quantification of basic drug species in human biological fluids and in pharmaceutical formulations.
Predicting bioavailability of PAHs and PCBs with porewater concentrations measured by solid-phase microextraction fibers
Authors: Lu Xiaoxia , Skwarski Alison , Drake Brian , Reible Danny D 
Published: February 2011

Abstract
Bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) was measured in the deposit-feeding oligochaete Ilyodrilus templetoni exposed for 28 d to Anacostia River sediment (Washington, DC, USA) and to an initially uncontaminated sediment from Brown Lake (Vicksburg, MS, USA) sequentially diluted with 3 to 25% contaminated New Bedford Harbor sediment (New Bedford, MA, USA). The Anacostia River sediment studies represented exposure to a historically contaminated sediment with limited availability, whereas exposure to the other sediment included both the historically contaminated New Bedford Harbor sediment and fresh redistribution of contaminants into the Brown Lake sediments. Organism tissue concentrations did not correlate with bulk sediment concentrations in the Anacostia River sediment but did correlate with the sequentially diluted sediment. Porewater concentrations measured via disposable solid-phase microextraction fiber (SPME) with polydimethylsiloxane (PDMS), however, correlated well with organism uptake in all sediments. Bioaccumulation was predicted well by a linear relationship with the product of porewater concentration and compound octanol–water partition coefficient (Anacostia, slope = 1.08, r2 = 0.76; sequentially diluted sediments, slope = 1.24, r2 = 0.76). The data demonstrate that the octanol–water partition coefficient is a good indicator of the lipid–water partition coefficient and that porewater concentrations provide a more reliable indicator of bioaccumulation in the organism than sediment concentrations, even when the route of uptake is expected to be via sediment ingestion. Environ. Toxicol. Chem. 2011; 30:1109–1116. © 2011 SETAC
Panic or not in fire: Clarifying the misconception
Authors: Fahy Rita F. , Proulx Guylène , Aiman Lata 
Published: February 2011

SUMMARYThe word ‘panic’ is frequently used in media accounts and statements of survivors of emergency evacuations and fires, but what does it really mean, is it a phenomenon that actually occurs? This paper first examines the concept from the view of the general public, particularly the media. Definitions of panic behaviour related to emergency response are summarized and evidence of behaviour from actual fire incidents are presented through interview data and case studies. Despite the data demonstrating that panic is a very rare occurrence in fires, the idea of panic and the term continue to be used by the public as well as fire experts. It is therefore necessary to demystify the misconception that panic is an essential element of a fire and identify any scientific justification for continuing to use this concept. Copyright © 2011 John Wiley & Sons, Ltd.
Differential involvement of noradrenaline and nitric oxide in the regulation of vasopressin and oxytocin expression in rat supraoptic nucleus
Authors: Raison Danièle , Hardin‐Pouzet Hélène , Grange‐Messent Valérie 
Published: February 2011

AbstractThe hydroosmotic balance of the body is controlled by supraoptic nuclei and paraventricular nuclei of the hypothalamo‐posthypophyseal complex. In response to a physiological stimulation such as an osmotic stress, the supraoptic nuclei (SON) and the paraventricular nuclei undergo remarkable neurochemical and morphological changes. Therefore, the neuroendocrine hypothalamus is a particularly relevant model for studying the molecular and cellular mechanisms that govern these plasticity phenomena. Slices of rat hypothalamus maintained ex vivo by perfusion were used to study the short‐term involvement of noradrenaline (NA) and nitric oxide (NO) in the mechanisms of chemical plasticity of the SON. NA is involved early in the regulation of the expression of neuropeptides, including vasopressin (AVP) and oxytocin (OT). NO appears to be a key molecule in noradrenergic control of the chemical plasticity of the endocrine neurons: in the SON, NO is involved in the signaling pathway regulating the expression of AVP but not that of OT. © 2011 Wiley‐Liss, Inc.