bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microchip capillary gel electrophoresis of multiply PEGylated high‐molecular‐mass glycoproteins
Authors: Seyfried Birgit K. , Marchetti‐Deschmann Martina , Siekmann Jürgen , Bossard Mary J. , Scheiflinger Friedrich , Turecek Peter L. , Allmaier Günter 
Published: March 2012

AbstractPEGylation is the most successful approach, to date, to prolong the in vivo survival of recombinant proteins. The conjugation of the polymer to glycoproteins results in challenging analysis, and furthermore, requires a wide variety of analytical tools for the determination of the extent of PEGylation. Herein, we present microchip capillary gel electrophoresis (MCGE) with a non‐commercial high‐molecular‐weight protein assay for the analysis of the PEGylation degree with a focus on multiple PEGylation. To show the potential of the modified MCGE system, high‐mass PEGylated glycoproteins (e.g. coagulation factor VIII) were analyzed. For the von Willebrand factor, the influence of glycans and the hydrodynamic radius on migration time and molecular weight determination is shown. The modified MCGE assay system is a powerful tool for the rapid assessment of the degree of PEGylation, demonstrating conjugate quality or reaction control of PEGylated proteins. This is the main advantage over time‐consuming conventional SDS‐PAGE. Furthermore, electrophoretic separation, staining, destaining, and fluorescence detection in one step combined with automated data analysis show that the MCGE system is a promising technique for high‐throughput monitoring. The MCGE system can be used for rapid structure confirmation (“MCGE fingerprinting”) of multiply PEGylated glycoproteins beyond the 230 kDa molecular mass range.See accompanying commentary by Yoshimoto and Yamamoto DOI: 10.1002/biot.201200143
Biosafety evaluation of recombinant protein production in goat mammary gland using adenoviral vectors: Preliminary study
Authors: Rodríguez Elaine Santana , Pose Alaín González , Moltó María Pilar Rodríguez , Espinoza Angela Sosa , Zamora Pastor Alfonso , Pedroso Marisela Suárez 
Published: March 2012

AbstractThe production of recombinant proteins in the milk of non‐transgenic goats can be achieved by transducing the mammary gland with recombinant adenoviral vectors. However, this process involves several regulatory issues. The current study evaluates the biosafety of this production system. We present a preliminary biosafety profile based on detection of adenoviral particles in different body fluids and the antibody response after adenoviral transduction of the goat mammary gland. In addition, two methods of adenoviral inactivation in milk were tested. Although adenoviral particles were detected in the milk until day 4 after transduction, they were absent in serum, saliva, urine and feces. Anti‐adenovirus antibodies were detected in serum and milk. The virus inactivation methods neutralized adenoviral particles and preserved the immunological identity of the recombinant protein. These results support the idea of a safe production of recombinant proteins using adenoviral vectors.
Dissecting a role of evolutionary‐conserved but noncritical disulfide bridges in cysteine‐rich peptides using ω‐conotoxin GVIA and its selenocysteine analogs
Authors: Gowd Konkallu Hanumae , Blais Kirk D. , Elmslie Keith S. , Steiner Andrew M. , Olivera Baldomero M. , Bulaj Grzegorz 
Published: March 2012

AbstractConotoxins comprise a large group of peptidic neurotoxins that use diverse disulfide‐rich scaffolds. Each scaffold is determined by an evolutionarily conserved pattern of cysteine residues. Although many structure–activity relationship studies confirm the functional and structural importance of disulfide crosslinks, there is growing evidence that not all disulfide bridges are critical in maintaining activities of conotoxins. To answer the fundamental biological question of what the role of noncritical disulfide bridges is, we investigated function and folding of disulfide‐depleted analogs of ω‐conotoxin GVIA (GVIA) that belongs to an inhibitory cystine knot motif family and blocks N‐type calcium channels. Removal of a noncritical Cys1–Cys16 disulfide bridge in GVIA or its selenopeptide analog had, as predicted, rather minimal effects on the inhibitory activity on calcium channels, as well as on in vivo activity following intracranial administration. However, the disulfide‐depleted GVIA exhibited significantly lower folding yields for forming the remaining two native disulfide bridges. The disulfide‐depleted selenoconotoxin GVIA analog also folded with significantly lower yields, suggesting that the functionally noncritical disulfide pair plays an important cooperative role in forming the native disulfide scaffold. Taken together, our results suggest that distinct disulfide bridges may be evolutionarily preserved by the oxidative folding or/and stabilization of the bioactive conformation of a disulfide‐rich scaffold. © 2011 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 98: 212–223, 2012.
Crystal structure of (Gly‐Pro‐Hyp)9: Implications for the collagen molecular model
Authors: Okuyama Kenji , Miyama Keita , Mizuno Kazunori , Bächinger Hans Peter 
Published: March 2012

AbstractCollagens have long been believed to adopt a triple‐stranded molecular structure with a 10/3 symmetry (ten triplet units in three turns) and an axial repeat of 29 Å. This belief even persisted after an alternative structure with a 7/2 symmetry (seven triplet units in two turns) with an axial repeat of 20 Å had been proposed. The uncertainty regarding the helical symmetry of collagens is attributed to inadequate X‐ray fiber diffraction data. Therefore, for better understanding of the collagen helix, single‐crystal analyses of peptides with simplified characteristic amino acid sequences and similar compositions to collagens have long been awaited. Here we report the crystal structure of (Gly‐Pro‐Hyp)9 peptide at a resolution of 1.45 Å. The repeating unit of this peptide, Gly‐Pro‐Hyp, is the most typical sequence present in collagens, and it has been used as a basic repeating unit in fiber diffraction analyses of collagen. The (Gly‐Pro‐Hyp)9 peptide adopts a triple‐stranded structure with an average helical symmetry close to the ideal 7/2 helical model for collagen. This observation strongly suggests that the average molecular structure of collagen is not the accepted Rich and Crick 10/3 helical model but is a 7/2 helical conformation. © 2012 Wiley Periodicals, Inc. Biopolymers 97: 607–616, 2012.
UNAC tetraloops: to what extent do they mimic GNRA tetraloops?
Authors: Zhao Qin , Huang Hung‐Chung , Nagaswamy Uma , Xia Youlin , Gao Xiaolian , Fox George E. 
Published: March 2012

AbstractThe structures of four small RNAs each containing a different version of the UNAC loop were determined in solution using NMR spectroscopy and restrained molecular dynamics. The UMAC tetraloops (where M is A or C) exhibited a typical GNRA fold including at least one hydrogen bond between the first U and fourth C. In contrast, UGAC and UUAC tetraloops have a different orientation of the first and fourth residues, such that they do not closely mimic the GNRA fold. Although the UMAC tetraloops are excellent structural mimics of the GNRA tetraloop backbone, sequence comparisons typically do not reveal co‐variation between the two loop types. The limited covariation is attributed to differences in the location of potential hydrogen bond donors and acceptors as a result of the replacement of the terminal A of GNRA with C in the UMAC version. Thus, UMAC loops do not readily form the common GNRA tetraloop‐receptor interaction. The loop at positions 863‐866 in E. coli 16S ribosomal RNA appears to be a major exception. However, in this case the GNRA loop does not in fact engage in the usual base to backbone tertiary interactions. In summary, UMAC loops are not just an alternative sequence version of the GNRA loop family, but instead they expand the types of interactions, or lack thereof, that are possible. From a synthetic biology perspective their inclusion in an artificial RNA may allow the establishment of a stable loop structure while minimizing unwanted long range interactions or permitting alternative long‐range interactions. © 2012 Wiley Periodicals, Inc. Biopolymers 97: 617–628, 2012.
Metabolite profiling of CHO cells with different growth characteristics
Authors: Dietmair Stefanie , Hodson Mark P. , Quek Lake‐Ee , Timmins Nicholas E. , Chrysanthopoulos Panagiotis , Jacob Shana S. , Gray Peter , Nielsen Lars K. 
Published: March 2012

AbstractMammalian cell cultures are the predominant system for the production of recombinant proteins requiring post‐translational modifications. As protein yields are a function of growth performance (among others), and performance varies greatly between culture medium (e.g., different growth rates and peak cell densities), an understanding of the biological mechanisms underpinning this variability would facilitate rational medium and process optimization, increasing product yields, and reducing costs. We employed a metabolomics approach to analyze differences in metabolite concentrations of CHO cells cultivated in three different media exhibiting different growth rates and maximum viable cell densities. Analysis of intra‐ and extracellular metabolite concentrations over the course of the cultures using a combination of HPLC and GC‐MS, readily detected medium specific and time dependent changes. Using multivariate data analysis, we identified a range of metabolites correlating with growth rate, illustrating how metabolomics can be used to relate gross phenotypic changes to the fine details of cellular metabolism. Biotechnol. Bioeng. 2012; 109:1404–1414. © 2012 Wiley Periodicals, Inc.
Clinical anatomy related to the hepatic veins for right lobe living donor liver transplantation
Authors: Liu Jing , Chen Da‐Feng , Chen Wen‐You , Guo Hua , Li Zhong‐Hua 
Published: March 2012

AbstractThe complexity of liver reconstruction has limited partial right lobe living donor liver transplantation. It is largely due to the difficulty of dealing with the middle hepatic vein. We sought to define the anatomic features of hepatic veins. Forty‐one fresh adult livers, 43 formalin‐fixed adult cadaver livers, and 91 adult liver corrosion casts were used for the study. We determined the number of branches, the maximum diameter, the whole length, the extrahepatic length of the hepatic veins, and the deviation of the middle hepatic vein from the main portal fissure. Nakamura and Tsuzuki's classification of hepatic vein types was used. Type A, B, and C accounted for 59.4, 27.8, and 12.8% of all specimens in this study, respectively. The middle and left hepatic veins formed a common trunk in 60.3% of the specimens, and the length of the common trunk was 1.12 ± 0.62 cm. The degree of deviation to the right of the middle hepatic vein from the main portal fissure was 14.11° ± 12.65°. The frequency of hepatic vein types and the degree of deviation to the right of the middle hepatic vein in this study is markedly different from that reported in other literature. The anatomic features of the hepatic veins in this study suggest that right lobe living donor liver transplantation is more suitable for Chinese. Clin. Anat. 2013. © 2012 Wiley Periodicals, Inc.
A Systems Approach for Process Simplification through Process Integration
Authors: Gopalakrishnan M. , Ponce‐Ortega J. M. , El‐Halwagi M. M. 
Published: March 2012

AbstractA new approach for process intensification through process simplification is proposed. This approach is based on a mass‐integration framework for reducing the number of processing steps for grassroots and retrofit designs. Two procedures are presented based on graphical and mathematical programming techniques. The process simplification task is aimed at synthesizing process configurations that involve the least number of processing steps while yielding a certain product from a set of raw materials. The new concepts of maximum extendible zones and product paths are introduced and incorporated into the design procedure. The solution identifies the simplest processes along with their configuration, stream distribution, and basic performance data.
A Strategy for the Synthesis of Mesostructured Metal Oxides with Lower Oxidation States
Authors: Tüysüz Harun , Weidenthaler Claudia , Schüth Ferdi 
Published: March 2012

AbstractA detailed study on the pseudomorphic conversion of ordered mesoporous Co3O4 and ferrihydrite into CoO and Fe3O4, respectively, by using alcohol/water vapor as a gentle reducing agent is described. The reduction conditions for the transformation were optimized. In addition, the first one‐pot synthesis of mesostructured CoO by using nanocasting with cubic ordered silica as a hard template is demonstrated.
The Effect of Neutral Ion Aggregate Formation on the Electrical Conductivity of an Ionic Liquid and its Mixtures with Chloroform
Authors: Köddermann Thorsten , Klembt Sandra , Klasen Dagmar , Paschek Dietmar , Kragl Udo , Ludwig Ralf 
Published: March 2012

AbstractWe have studied the electrical conductivity of mixtures of the ionic liquid (IL) [C2mim][NTf2] with chloroform for various concentrations at a temperature of 303 K by both experiments and MD simulations. The molar conductivities exhibit an initial increase with decreasing IL concentration, which again sharply decreases in the region of highly diluted IL concentrations. This behavior is according to a competition between 1) the decreasing viscosity with increasing chloroform concentration due to fluidizing the mixture, and 2) the decreasing amount of charge carriers due to the formation of neutral IL aggregates. The simulated molar conductivities and their concentration dependence are found to be in reasonable agreement with the experimentally determined values, suggesting that essential correlations between the solvated ionic species in the solution are well represented. Both experiments and simulations show that the Nernst–Einstein relation drastically overestimates the conductivity of the solutions at low IL concentrations. According to our MD simulation data, this observation is due to the extensive formation of neutral aggregates in the low‐concentration regime.
Orientational Ordering of Ionic Liquids near a Charged Mica Surface
Authors: Singh Payal Rajdeep , Balasubramanian Sundaram 
Published: March 2012

AbstractThe self‐assembly of ions in room‐temperature ionic liquids adsorbed on a mica surface is studied using molecular dynamics simulations. Four liquids from the 1‐methyl,n‐alkylimidazolium bis(trifluoromethylsulfonyl)imide ([Cnmim][NTf2]) family are investigated, where n ranges between 2 and 8. Cations with ethyl or butyl groups are found to orient with the hydrocarbon tails lying parallel to the surface, while the hexyl and octyl tails of cations are observed to be oriented perpendicular to it. The crossover in the orientational preference matches recent observations of surface forces of these liquids.
The Influence of Defects on Mo‐Doped TiO2 by First‐Principles Studies
Authors: Yu Xiaohui , Hou Tingjun , Sun Xuhui , Li Youyong 
Published: March 2012

AbstractTiO2 doped with transition metals shows improved photocatalytic efficiency. Herein the electronic and optical properties of Mo‐doped TiO2 with defects are investigated by DFT calculations. For both rutile and anatase phases of TiO2, the bandgap decreases continuously with increasing Mo doping level. The 4d electrons of Mo introduce localized states into the forbidden band of TiO2, and this shifts the absorption edge into the visible‐light region and enhances the photocatalytic activity. Since defects are universally distributed in TiO2 or doped TiO2, the effect of oxygen deficiency due to oxygen vacancies or interstitial Mo atoms is systemically studied. Oxygen vacancies associated with the Mo dopant atoms or interstitial Mo will reduce the spin polarization and magnetic moment of Mo‐doped TiO2. Moreover, oxygen deficiency has a negative impact on the improved photocatalytic activity of Mo‐doped TiO2. The current results indicate that substitutional Mo, interstitial Mo, and oxygen vacancy have different impacts on the electronic/optical properties of TiO2 and are suited to different applications.
Preparation of [Al(hfip)4]−‐Based Ionic Liquids with Siloxane‐Functionalized Cations and Their Physical Properties in Comparison with Their [Tf2N]− Analogues
Authors: Bulut Safak , Ab Rani M. A. , Welton Tom , Lickiss Paul D. , Krossing Ingo 
Published: March 2012

AbstractTwo new ionic liquids (ILs) with siloxane‐functionalized cations and the weakly coordinating tetraalkoxyaluminate [Al(hfip)4]− (hfip=hexafluoroisopropoxy) are prepared and characterized by nuclear magnetic resonance (NMR), infrared (IR) and Raman spectroscopy. With melting points below 0 °C they qualify as room temperature ILs (RTILs). Their temperature‐dependent viscosities and conductivities, together with those of two [Tf2N]− ILs with the same cations and a further siloxane‐functionalized [Tf2N]− IL, are measured between 0 and 80 °C, and all are described by the Vogel–Fulcher–Tammann (VFT) equations. We note that the [Al(hfip)4]− ILs have lower viscosities than their [Tf2N]− analogues at all measured temperatures and higher conductivities at room temperature.
Theoretical Investigation on SERS of Pyridine Adsorbed on Cn Clusters Induced by Charge Transfer: A Hint that SERS Could be Applied on Many Materials
Authors: Kong Xiangkai , Chen Qianwang , Li Ran , Cheng Kai , Yan Nan , Chen Jian , Zhou Yumei 
Published: March 2012

AbstractThe SERS spectra of pyridine–Cn (n=1–6) complexes are investigated theoretically. The obtained enhancement factors of about 102–103 in the pre‐resonance Raman spectrum calculations are attributed to charge‐transfer transitions from the carbon clusters to pyridine, where a good match of band structures between substrates and probe molecules is essential.
Synthesis of flower‐like zinc oxide and polyaniline with worm‐like morphology and their applications in hybrid solar cells
Authors: Mavundla S. E. , Malgas G. F. , Motaung D. E. , Iwuoha E. I. 
Published: March 2012

AbstractZnO with a “flower‐like” morphology was synthesized using a simple microwave assisted hydrothermal method and used as an acceptor material in hybrid solar cells. X‐Ray diffraction and Raman Spectroscopy confirmed the formation of a highly crystalline wurtzite ZnO structure. A highly crystalline and conductive polyaniline with “worm‐like” morphology was synthesized by chemical polymerization of aniline using KH(IO3)2 as an oxidant and was used as a donor material for solar cells. The morphology was probed by using scanning and transmission electron microscopy. Polyaniline with worm‐like morphology had a diameter of 160 nm and about 2 µm long. Solar cell device fabricated from PANI/ZnO active bilayer demonstrated a fill factor of about 22.8%. Upon blending PANI with ZnO the fill factor was improved to 25.6% and efficiency by almost 100 fold when PANI:ZnO 1:1 composite was used as an bulk heterogeneous active layer. The fill factor was further improved to 26.4% when device architecture was changed to diffused bilayer. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis by precipitation method and investigation of SnO2 nanoparticles
Authors: Nejati K. 
Published: March 2012

AbstractIn this paper the synthesis of SnO2 nanoparticles with average particle size up to about 70 nm using SnCl22H2O and NH4OH in 1‐botanol solution by the precipitation method is reported and the inhibition of sodium dodecyl sulphate (SDS) on the SnO2 particle growth is investigated by soaking SnO2precursor in the SDS solution for 24 h. The as‐prepared SnO2and SDS modified‐SnO2 powders, then, were calcined at different temperatures and the X‐ray powder diffraction (XRD) and Fourier transform infrared spectroscopy (FT‐IR) were used to characterize the output samples. The XRD results reveal that the structure of tin‐dioxide is tetragonal rutile and the as‐prepared SnO2 nanoparticles grow with increasing the annealing temperature, while the SDS treatment prevents the particle growth under the same condition. Furthermore, the FT‐IR results indicate the formation of tin‐hydroxyl group which are then converted into tin‐dioxide with heat treatment. Further characterization of the samples by the transmission electron microscopy (TEM) and the photoluminescence (PL) spectroscopy was carried out. The room temperature PL spectra of SnO2exhibits broad and strong peak attributed to the surface defects such as oxygen vacancies and intensity of which decreases with the increase in particle size. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
In search for cross‐reactivity to immunophenotype equine mesenchymal stromal cells by multicolor flow cytometry
Authors: De Schauwer Catharina , Piepers Sofie , Van de Walle Gerlinde R. , Demeyere Kristel , Hoogewijs Maarten K. , Govaere Jan L. J. , Braeckmans Kevin , Van Soom Ann , Meyer Evelyne 
Published: March 2012

AbstractDuring recent years, cell‐based therapies using mesenchymal stem cells (MSC) are reported in equine veterinary medicine with increasing frequency. In most cases, the isolation and in vitro differentiation of equine MSC are described, but their proper immunophenotypic characterization is rarely performed. The lack of a single marker specific for MSC and the limited availability of monoclonal antibodies (mAbs) for equine MSC in particular, strongly hamper this research. In this study, 30 commercial mAbs were screened with flow cytometry for recognizing equine epitopes using the appropriate positive controls to confirm their specificity. Cross‐reactivity was found and confirmed by confocal microscopy for CD45, CD73, CD79α, CD90, CD105, MHC‐II, a monocyte marker, and two clones tested for CD29 and CD44. Unfortunately, none of the evaluated CD34 clones recognized the equine epitopes on positive control endothelial cells. Subsequently, umbilical cord blood‐derived undifferentiated equine MSC of the fourth passage of six horses were characterized using multicolor flow cytometry based on the selected nine‐marker panel of both cell surface antigens and intracytoplasmatic proteins. In addition, appropriate positive and negative controls were included, and the viable single cell population was analyzed by excluding dead cells using 7‐aminoactinomycin D. Isolated equine MSC of the fourth passage were found to be CD29, CD44, CD90 positive and CD45, CD79α, MHC‐II, and a monocyte marker negative. A variable expression was found for CD73 and CD105. Successful differentiation towards the osteogenic, chondrogenic, and adipogenic lineage was used as additional validation. We suggest that this selected nine‐marker panel can be used for the adequate immunophenotyping of equine MSC. © 2012 International Society for Advancement of Cytometry
How many therapists? Practical guidance on investigating therapist effects in randomized controlled trials for eating disorders
Authors: Thompson Doug , Cachelin Fary , Striegel‐Moore Ruth H. , Barton Bruce , Shea Munyi , Wilson G. Terence 
Published: March 2012

AbstractObjective:An important question in implementation/dissemination research is whether the efficacy of a given treatment varies in part based on the therapist delivering the treatment. This study sought to provide practical guidance to researchers in the field of eating disorders for building measurement of therapist effects into the design of a typical, relatively small randomized controlled trial (RCT).Method:Using assumptions based on past trials of eating disorder treatments, Monte Carlo simulations were used to examine 12 different scenarios based on crossing the number of therapists (between two and five) and the estimated therapist effect size (small, medium, and large). Patient sample size and study design were held constant.Results:There was reasonable power (≥70%) to detect the therapist effect with three or four therapists and a large effect size.Discussion:Several practical implications for testing therapist effects in RCT are discussed. © 2012 by Wiley Periodicals, Inc. Int J Eat Disord 2012.