bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fabrication of continuous aligned polyvinylpyrrolidone fibers via electrospinning by elimination of the jet bending instability
Authors: Cui Xiaojie , Li Luming , Xu Jun , Xu Fu 
Published: February 2010

AbstractIn this study, we successfully fabricated highly aligned polyvinylpyrrolidone (PVP) fibers and crossed mats by restraining and eliminating the jet bending instability through a dual‐opposite‐spinnerets electrospinning (DOSES) method. The DOSES process was photographed by a digital camera, and the morphology of the fibers was analyzed with field emission scanning electron microscopy. We argue that the elimination of the jet whipping and bending instability was achieved by adjusting the concentration of the polymer solution. When the concentration of PVP solution was raised to more than 15 wt %, two individual fibers stuck together were obtained without the appearance of the jet bending instability at a suitable take‐up velocity. This study demonstrated solid improvement in both the alignment of the polymer yarns and the fabrication of individual fibers side by side. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Polymer‐coated piezoelectric quartz crystal sensor for sensing the nerve agent simulant dimethyl methylphosphonate vapor
Authors: Maji S. , Asrey R. , Kumar S. , Saxena C. , Kumar N. , Vyas K. D. , Banerjee S. 
Published: February 2010

AbstractA chemical vapor sensor based on a quartz crystal microbalance was fabricated with a 10‐MHz quartz crystal oscillator. The quartz crystals were coated with four newly synthesized polymers and were studied for the detection of the nerve agent simulant dimethyl methylphosphonate vapor. The sensor was tested for immediate and extended periods of time. Various sensing parameters (e.g., the sensitivity, response time, and recovery time) were evaluated with respect to different coating materials. All the polymers showed fairly good baseline stability even after several cycles. The highest frequency drift of 23.8 Hz/kHz was observed for one of the polymers, whereas another polymer showed the best sensing stability over an extended period of 250 days. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Reduction of postsurgical adhesion formation with CM‐chitosan hydrogel barriers prepared by using γ‐irradiation
Authors: Gwon Hui‐Jeong , Lim Youn‐Mook , Chang Ho‐Nam , Nho Young‐Chang 
Published: February 2010

AbstractTo evaluate the efficiency of carboxymethylchitosan (CM‐chitosan)‐based hydrogels as barriers for reducing postsurgical adhesions, CM‐chitosan was synthesized to simplify the hydrogel‐making process, and the CM‐chitosan solutions were cross‐linked by using γ‐ray irradiation to create the desired hydrogels instead of using chemical cross‐linking reagents. The prepared CM‐chitosan hydrogels were characterized by a FTIR spectroscopy, swelling behavior, gel‐fraction content,and mechanical property such as gel strength of a hydrogel and the results showed a good swelling behavior and mechanical properties. Also, the radiation‐induced CM‐chitosan hydrogels significantly reduced and inhibited the postsurgical adhesions in the rat models. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Induction of CD44 cleavage in articular chondrocytes
Authors: Takahashi Nobunori , Knudson Cheryl B. , Thankamony Sai , Ariyoshi Wataru , Mellor Liliana , Im Hee‐Jeong , Knudson Warren 
Published: February 2010

AbstractObjectiveThe hyaluronan receptor CD44 provides chondrocytes with a mechanism for sensing and responding to changes in the extracellular matrix. The purpose of this study was to document the fragmentation and loss of CD44 and to determine the likely mechanisms involved.MethodsA polyclonal anti‐CD44 cytotail antibody was generated to detect CD44 fragmentation by Western blot analysis. Chondrocytes were isolated from human or bovine articular cartilage. Primary articular chondrocytes were treated with interleukin‐1β (IL‐1β), hyaluronan oligosaccharides, or phorbol myristate acetate or were passaged and subcultured in monolayer to induce dedifferentiation. Conditions that altered the capacity of CD44 to transit into lipid rafts, or pharmacologic inhibitors of metalloproteinase or γ‐secretase activity were used to define the mechanism of fragmentation of CD44.ResultsChondrocytes from osteoarthritic cartilage exhibited CD44 fragmentation as low molecular mass bands, corresponding to the CD44‐EXT and CD44‐ICD bands. Following dedifferentiation of chondrocytes or treatment of primary chondrocytes with hyaluronan oligosaccharides, IL‐1β, or phorbol myristate acetate, CD44 fragmentation was enhanced. Subsequent culture of the dedifferentiated chondrocytes in 3‐dimensional alginate beads rescued the chondrocyte phenotype and diminished the fragmentation of CD44. Fragmentation of CD44 in chondrocytes was blocked in the presence of the metalloproteinase inhibitor GM6001 and the γ‐secretase inhibitor DAPT.ConclusionCD44 fragmentation, consistent with a signature pattern reported for sequential metalloproteinase/γ‐secretase cleavage of CD44, is a common metabolic feature of chondrocytes that have undergone dedifferentiation in vitro and osteoarthritic chondrocytes. Transit of CD44 into lipid rafts may be required for its fragmentation.
Synovial tissue heterogeneity in rheumatoid arthritis in relation to disease activity and biomarkers in peripheral blood
Authors: van Baarsen Lisa G. M. , Wijbrandts Carla A. , Timmer Trieneke C. G. , van der Pouw Kraan Tineke C. T. M. , Tak Paul P. , Verweij Cornelis L. 
Published: February 2010

AbstractObjectiveTo investigate the clinical relevance of synovial tissue subtypes in rheumatoid arthritis (RA) and to search for peripheral blood (PB) markers that may serve as biomarkers for tissue subtypes.MethodsGene expression analysis using complementary DNA microarrays was applied on paired synovial tissue biopsy and PB samples obtained from 17 RA patients. Molecular tissue subtypes were correlated with histologic parameters (CD3, CD22, CD38, CD68, CD163, tumor necrosis factor α, intercellular adhesion molecule 1, vascular cell adhesion molecule, and E‐selectin), disease characteristics, and PB markers. PANTHER classification was used for pathway analysis.ResultsGenomic subtyping of high‐ and low‐inflammation rheumatoid synovial tissues based on gene expression profiles exactly matched immunohistochemical classification. The patients with the high‐inflammation tissue type had higher Disease Activity Scores in 28 joints, higher C‐reactive protein levels, higher erythrocyte sedimentation rates, increased numbers of platelets, and shorter disease durations. Comparative analysis of PB gene expression profiles yielded no statistically significant differences between the 2 tissue groups at the single‐gene expression level. PANTHER pathway analysis revealed a significant association of increased protein biosynthesis with high‐inflammation tissue.ConclusionHigh‐inflammation tissue is associated with more severe disease and shorter disease duration. While pathway‐level analysis revealed that coordinate differential expression of genes involved in protein synthesis in PB is associated with high‐inflammation tissue types, differential tissue pathology was not reflected in the PB by differential expression of single genes.
Lower expression levels of the programmed death 1 receptor on CD4+CD25+ T cells and correlation with the PD‐1.3A genotype in patients with systemic lupus erythematosus
Authors: Kristjansdottir Helga , Steinsson Kristjan , Gunnarsson Iva , Gröndal Gerdur , Erlendsson Kristjan , Alarcón‐Riquelme Marta E. 
Published: February 2010

AbstractObjectiveA genetic polymorphism in the programmed death 1 (PD‐1) gene encoding the coinhibitory PD‐1 immunoreceptor, PD‐1.3A, is associated with systemic lupus erythematosus (SLE). The aim of this study was to assess PD‐1 receptor expression in patients with SLE, in comparison with relatives and unrelated healthy controls, and to identify correlations of lower expression levels of PD‐1 receptor with the PD‐1.3A genotype.MethodsPatients with SLE, patients' relatives, and unrelated healthy control subjects from Iceland and Sweden were studied. Peripheral blood mononuclear cells (PBMCs) were stimulated with anti‐CD3/anti‐CD28, and PD‐1 expression was analyzed by flow cytometry. PD‐1.3A/G genotyping was performed using polymerase chain reaction–restriction fragment length polymorphism analysis.ResultsPD‐1 expression on PBMCs was induced after antibody stimulation, showing increases of 2.1‐fold in SLE patients, 3.1‐fold in relatives, and 5.1‐fold in healthy controls. The frequency of PD‐1+ cells was significantly lower in SLE patients compared with relatives and healthy controls. PD‐1 expression on PD‐1+ cells and on CD4+CD25+ T cells was significantly lower in SLE patients and relatives compared with healthy controls. PD‐1 expression was significantly elevated on CD25high cells. Levels of PD‐1 expression on CD25high and CD25intermediate cells were significantly lower in SLE patients compared with healthy controls. PD‐1 was expressed on both FoxP3− and FoxP3+ cells. Lower expression of PD‐1 was significantly correlated with the PD‐1.3A/G genotype.ConclusionThe results demonstrate significantly lower PD‐1 receptor expression in SLE patients and their relatives and reveal a significant correlation of lower PD‐1 expression with the PD‐1.3A allele. Thus, PD‐1.3A may contribute to abnormalities in PD‐1 receptor expression on CD4+CD25+ T cells in patients with SLE, providing support for an important role of the PD‐1 pathway in SLE and, possibly, in other autoimmune diseases.
Synthesis and Characterization of Gold‐Nanoparticle‐Cored Dendrimers Stabilized by Metal–Carbon Bonds
Authors: Kumar Venugopal K. Ratheesh , Gopidas Karical R. 
Published: February 2010

AbstractSynthesis and characterization of gold‐nanoparticle‐cored dendrimers (NCDs), in which the dendrons are attached to the gold core through gold–carbon bonds, are described. Synthesis of these materials involved the simultaneous reduction of HAuCl4 and a Fréchet‐type dendron with a diazonium group at the focal point, all in an organic solvent such as toluene. These materials possess a nanometer‐sized gold core surrounded by a shell of polyaryl ether dendrons, which are connected radially to the core. The NCDs were characterized by TEM, thermogravimetric analysis (TGA), and IR, UV, and NMR spectroscopic techniques. Average particle diameter of the NCDs ranged from 4.7 to 5.5 nm for the different generations. All NCDs exhibit the characteristic plasmon absorption of gold nanoparticles at 520 nm. Average numbers of dendrons per NCD in AuGn were calculated using results from TGA and TEM studies. Multiple layering of the dendrons is proposed as a possible reason for the high dendron/NCD value.
Rapid determination of antigenic epitopes in human NGAL using NMR
Authors: Olejniczak Edward T. , Ruan Qiaoqiao , Ziemann Robert N. , Birkenmeyer Larry G. , Saldana Sylvia C. , Tetin Sergey Y. 
Published: February 2010

AbstractThe recent remarkable rise in biomedical applications of antibodies and their recombinant constructs has shifted the interest in determination of antigenic epitopes in target proteins from the areas of protein science and molecular immunology to the vast fields of modern biotechnology. In this article, we demonstrated that measuring binding induced changes in two‐dimensional NMR spectra enables rapid determination of antibody binding footprints on target protein antigens. Such epitopes recognized by six high‐affinity monoclonal murine antibodies (mAbs) against human neutrophil gelatinase‐associated lipocalin (NGAL) were determined by measuring chemical shifts or broadening of peaks in 1H‐15N‐TROSY HSQC and 1H‐13C HSQC spectra of isotope‐labeled NGAL occurring upon its binding to the antibodies. Locations of the epitopes defined by the NMR studies are in good agreement with the results of antibody binding pairing observed by dual‐color fluorescence cross‐correlation spectroscopy. In all six cases, the antibodies recognize conformational epitopes in regions of relatively rigid structure on the protein. None of the antibodies interact with the more flexible funnel‐like opening of the NGAL calyx. All determined epitope areas in NGAL reflect the dimensions of respective antibody binding surface (paratopes) and contain amino acid residues that provide strong interactions. This NMR‐based approach offers comprehensive information on antigenic epitopes and can be applied to numerous protein targets of diagnostic or therapeutic interest. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 657–667, 2010.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
High‐level recombinant protein production in CHO cells using lentiviral vectors and the cumate gene‐switch
Authors: Gaillet Bruno , Gilbert Rénald , Broussau Sophie , Pilotte Amélie , Malenfant Félix , Mullick Alaka , Garnier Alain , Massie Bernard 
Published: February 2010

AbstractFast and efficient production of recombinant proteins for structural and functional studies is a crucial issue for research and for industry. To this end, we have developed an efficient system to generate in less than 2 months, starting from the cDNA, pools of CHO cells stably expressing high‐level of recombinant proteins. It is based on lentiviral vectors (LVs) for stable transduction coupled with the cumate gene‐switch for inducible and efficient gene expression. Transcription is initiated upon binding of the cumate transactivator (cTA) or the reverse cTA (rcTA) to the CR5 promoter. Binding of cTA or rcTA is prevented or induced by addition of cumate respectively. We first validated the CHO/LV production system with an LV carrying the secreted alkaline phosphatase (SEAP), whose expression was linked to the green fluorescent protein (GFP) through an internal ribosome entry site (IRES). CHO cells stably expressing the cTA (CHO‐cTA) were transduced at various multiplicity of infection (MOI). Pools of cells were incubated at 37 and 30°C during 10 days. Optimal SEAP production (65 µg/mL) was achieved at 30°C with a MOI of 200. The pool stability was demonstrated for 48 days of culture by GFP expression analysis. The system was also evaluated using LV expressing three typical therapeutic proteins (a protein made up of the extracellular domain of CD200 fused to IgG Fc region [CD200Fc], a chimeric antibody [chB43], and erythropoietin [EPO]). CHO cells expressing rcTA (CHO‐Cum2) were transduced with these LVs at a MOI of 200 and production was tested at 30°C. After 13 days of culture, 235, 160, and 206 µg/mL of CD200Fc, chB43, and EPO were produced, respectively. The ON/OFF ratio of these pools was equal to 6 for CD200Fc, 16 for chB43, and 74 for EPO. In conclusion, this system should be very useful to produce mg quantities of recombinant proteins in a timely manner in serum free suspension culture of CHO cells for preclinical studies. Biotechnol. Bioeng. 2010;106: 203–215. © 2010 Wiley Periodicals, Inc.
Improving the long‐term storage of a mammalian biosensor cell line via genetic engineering
Authors: Petrovick Martha S. , Nargi Frances E. , Towle Theresa , Hogan Kristine , Bohane Marie , Wright Deborah J. , MacRae Thomas H. , Potts Malcolm , Helm Richard F. 
Published: February 2010

AbstractThe unique properties of mammalian cells make them valuable for a variety of applications in medicine, industry, and diagnostics. However, the utility of such cells is restricted due to the difficulty in storing them non‐frozen for an extended time and still maintaining their stability and responsiveness. In order to extend the active life span of a mammalian biosensor cell line at room and refrigerated temperatures, we have over expressed genes that are reported to provide protection from apoptosis, stress, or oxidation. We demonstrated that over expression of genes from the extremophile, Artemia franciscana, as well as GADD45β, extends room‐temperature storage of fully active cells 3.5‐fold, while over production of several anti‐apoptotic proteins extended 4°C storage 2‐ to 3‐fold. Methodologies like these that improve the stability of mammalian‐cell‐based technologies in the absence of freezers may enable widespread use of these tools in applications that have been considered impractical based solely on limited storage characteristics. Biotechnol. Bioeng. 2010; 106: 474–481. © 2010 Wiley Periodicals, Inc.
Novel method for measuring active tension generation by C2C12 myotube using UV‐crosslinked collagen film
Authors: Fujita Hideaki , Shimizu Kazunori , Nagamori Eiji 
Published: February 2010

AbstractWe have developed a novel method for measuring active tension generated by cultured myotubes using UV‐crosslinked collagen film. Skeletal myoblasts cell line C2C12 or human primary skeletal myoblasts were seeded onto a thin (35 µm) collagen film strip, on which they proliferated and upon induction of differentiation they formed multinucleated myotubes. The collagen film–myotube complex contracted upon electric pulse stimulation which could be observed by light microscope. When collagen film–myotube complex were attached to force transducer, active tension generation was observed upon electric pulse stimulation. Measurement of active tension was possible for multiple times for more than 1 month with the same batch of collagen film–myotube complex. Active tension generation capability of C2C12 myotubes increased with progression of differentiation, reaching maximal value 6 days after induction of differentiation. Using this method, we measured the effect of artificial exercise induced by electric pulse on active tension generation capability of C2C12 myotubes. When the electric pulses of 1 Hz were continuously applied to induce artificial exercise, the active tension augmentation was observed. After 1 week of artificial exercise, the active tension reached ∼10× of that before the exercise. The increased active tension is attributable to the formation of the sarcomere structure within the myotubes and an increased amount of myotubes on the collagen film. The increased amount of myotubes is possibly due to the suppressed atrophy of myotubes by enhanced expression of Bcl‐2. Biotechnol. Bioeng. 2010; 106: 482–489. © 2010 Wiley Periodicals, Inc.
Standstill frequency response test analyzer by using Excel Macros for educational purposes
Authors: Vahidi B. , Tavakoli M. R. Bank 
Published: February 2010

AbstractAccurate knowledge characteristics of a synchronous generator are very essential to have an idea of its operation conditions. In the presented paper generator standstill frequency response tests is used as an approach to derive dynamic models and equivalent circuits descriptive of machine behavior for dynamic studies by using Excel Macros. The method is described and applied to a case study. The extraction process for obtaining the parameters is demonstrated. Evaluation of the method with 20 senior under graduate students and 20 junior power system engineers is very positive in terms of their developing confidence in and understanding of this test and deriving the dynamic model. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 474–483, 2012
Teaching short‐circuit withstand test on power transformers to M.Sc. students and junior engineers using MATLAB‐SIMULINK
Authors: Vahidi B. , Agheli Smieee A. , Jazebi S. 
Published: February 2010

AbstractThis article describes an efficient method of teaching short‐circuit withstand test on power transformer to power system graduate students and junior power engineers. The purpose of the presented method could be a part of a high‐voltage course for M.Sc. students in electrical engineering departments and a train for junior engineers in industry. The article shows how to simulate the components of testing circuit and transformer to teach them the test. Evaluation of the simulations with 20 students and 20 junior engineers was very positive in terms of their developing confidence and understanding short‐circuit withstand test on power transformers. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 20: 484–492, 2012
2‐(1‐Ethynylpyrene)‐Adenosine as a Folding Probe for RNA—Pyrene in or out
Authors: Förster Ute , Lommel Katharina , Sauter Daniel , Grünewald Christian , Engels Joachim W. , Wachtveitl Josef 
Published: February 2010

AbstractA series of short RNA duplexes containing one or two 1‐ethynylpyrene‐modified adenine bases was synthesised. The melting behaviour of these duplexes was examined by monitoring temperature‐dependent pyrene fluorescence. In the singly modified RNA duplexes, the bases flanking the ethynylpyrene‐rA were varied to examine the sequence specificity of the fluorescence change of pyrene upon RNA hybridisation. Because an increase in pyrene fluorescence upon melting of the duplex can be correlated with intercalation of pyrene, and a decrease is usually associated with the position of pyrene outside the strand, a relationship between the flanking bases and the tendency of the dye to intercalate has been established. It was found that pyrene intercalation is less likely to take place if the modified base is flanked only by A–U base pairs. Flanking G–C base pairs, even only in the 5′‐direction of the modified base, will favour intercalation. In addition, we examined a doubly modified compound that had a pyrene located on each strand. The spectra indicated that the two pyrenes were close enough for interaction. Upon melting of the strand, a fluorescence blue shift corresponding to the dissociation of the pyrene–pyrene complex could be observed in addition to the intensity effect already known from the singly modified compounds. Two melting curves based on the different properties of the fluorophore could be extracted, leading to different melting points corresponding to the global duplex melting and to the change of local pyrene environment, respectively.
Ligand Close Packing, Molecular Compactness, the Methyl Tilt, Molecular Conformations, and a New Model for the Anomeric Effect
Authors: Gillespie Ronald J. , Robinson Edward A. , Pilmé Julien 
Published: February 2010

AbstractAll the atoms in a molecule attract each other until they reach their equilibrium positions at which point the repulsive forces between the atoms just balance the attractive forces and there are no resultant forces acting on any of the atoms in the molecule. Thus, we can consider that in the equilibrium geometry the atoms in a molecule are arranged as compactly as possible. This is the basis of the ligand close packing (LCP) model according to which three or four monatomic ligands X, such as F, Cl or O (formally O or O−) pack as closely as possible around a small central atom such as a boron or carbon atom giving a truly close‐packed equilateral triangular AX3molecule or a tetrahedral AX4molecules. Such monatomic ligands can, to a good approximation, be described as having a spherical shape with a single ligand radiusrX. In contrast, ligands with donor atoms with lone pairs such as the oxygen atom in an OX group have a less symmetrical electron density requiring two ligand radii,rin the lone pair direction, andrin the bonding direction, wherer<rfor an approximate description. On this basis we propose an explanation for the “methyl tilt”, in methanol and many related molecules, and in conjunction with the concept of compactness, a model for explaining the relative energies of the conformations of molecules containing OH and OMe ligands, including molecules that exhibit the anomeric effect. We compare our model for the anomeric effect with the widely accepted “hyperconjugation” model. We also discuss the relationship between the concept of compactness and the concept of hardness.