bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐dose lentiviral gene transfer for lifetime airway gene expression
Authors: Stocker Alice G. , Kremer Karlea L. , Koldej Rachel , Miller Darren S. , Anson Donald S. , Parsons David W. 
Published: July 2009

AbstractBackgroundCystic fibrosis (CF) is caused by a defect in cystic fibrosis transmembrane conductance regulator (CFTR) activity, often resulting in an incurable airway disease. Gene therapy into the conducting airway epithelium is a potential cure for CF; however, most gene vectors do not result in long‐lived expression, and require re‐dosing. Perversely, intrinsic host immune responses can then block renewed gene transfer.MethodsTo investigate whether persistent gene expression could be achieved after a single dosing event, thus avoiding the issue of blocking host responses, we used a gene transfer protocol that combined an airway pretreatment using lysophosphatidylcholine with a human immunodeficiency virus type‐1 (vesicular stomatitis virus G pseudotype) derived lentiviral vector to test whether an integrating vector could produce gene expression able to last for a substantial part of the lifetime of the laboratory mouse.ResultsWe found that a single dose of LV‐LacZ produced immediate as well as lifetime mouse airway expression, confirming our hypothesis that use of an integrating vector extends transgene expression. Importantly, LV‐CFTR dosing achieved at least 12 months of CFTR expression, representing partial functional correction of the CFTR defect in CF‐null mice.ConclusionsThese findings validate the potential of this methodology for developing a gene transfer treatment for CF airway disease. Copyright © 2009 John Wiley & Sons, Ltd.
Exhalation of respiratory viruses by breathing, coughing, and talking
Authors: Stelzer‐Braid Sacha , Oliver Brian G. , Blazey Angus J. , Argent Elizabeth , Newsome Timothy P. , Rawlinson William D. , Tovey Euan R. 
Published: July 2009

AbstractThere is a lack of quantitative information about the generation of virus aerosols by infected subjects. The exhaled aerosols generated by coughing, talking, and breathing were sampled in 50 subjects using a novel mask, and analyzed using PCR for nine respiratory viruses. The exhaled samples from a subset of 10 subjects who were PCR positive for rhinovirus were also examined by cell culture for this virus. Of the 50 subjects, among the 33 with symptoms of upper respiratory tract infections, 21 had at least one virus detected by PCR, while amongst the 17 asymptomatic subjects, 4 had a virus detected by PCR. Overall, rhinovirus was detected in 19 subjects, influenza in 4 subjects, parainfluenza in 2 subjects, and human metapneumovirus in 1 subject. Two subjects were co‐infected. Of the 25 subjects who had virus‐positive nasal mucus, the same virus type was detected in 12 breathing samples, 8 talking samples, and in 2 coughing samples. In the subset of exhaled samples from 10 subjects examined by culture, infective rhinovirus was detected in 2. These data provide further evidence that breathing may be a source of respirable particles carrying infectious virus. J. Med. Virol. 81:1674–1679, 2009. © 2009 Wiley‐Liss, Inc.
Dynamic changes of HBV quasispecies and deletion patterns in a chronic hepatitis B patient
Authors: Ji Fen , Zhou Li , Ma Sufang , Li Feifei , Ding Huiguo , Zeng Changqing 
Published: July 2009

AbstractHepatitis B virus (HBV) infection is a dynamic process during which molecular variants are selected continuously to adapt to changes. In addition to drug resistant mutations, sequential antiviral therapy may also lead to the selection of deleted mutants. To investigate this process, the following samples were collected from a patient who failed lamivudine therapy and then was switched to adefovir dipivoxil. HBV DNA was sequenced at two separate regions; a 1 kb region of reverse transcriptase (RT) and a 1.5 kb region encompassing the C gene and part of the preS gene. Sequence analysis of the RT region showed that the prevailing lamivudine resistant mutations were reduced after switching to adefovir dipivoxil, and ultimately the mutations were undetectable. Quasispecies distribution and deletion patterns in the C and preS regions were also different between the two antiviral therapies. In lamivudine‐treated samples, wild‐type strains (57.7%) were dominant and deletions in the preS region were observed. However, in the subsequent therapy involving adefovir dipivoxil, a virus population harboring 81 and 96 bp deletions (86%) in the C gene prevailed. Both major deletions encompassed T‐ and B‐cell epitopes. Meanwhile, the frequencies of the preS deletions decreased significantly, except for the 129 bp deletion. Notably, the presence of 81, 96, and 129 bp deletions was always accompanied with some nucleotide substitutions. In conclusion, the prevalence of deletions at the C gene epitopes accompanied with the gradual disappearance of lamivudine resistance mutations may contribute to the survival of HBV under sequential antiviral therapy. J. Med. Virol. 81:1551–1559, 2009. © 2009 Wiley‐Liss, Inc.
Thymosin beta‐4 directs cell fate determination of human mesenchymal stem cells through biophysical effects
Authors: Hui‐Chun Ho Jennifer , Ma Wei‐Hsien , Su Yeu , Tseng Kuang‐Ching , Kwang‐Chun Kuo Tom , Kuang‐Sheng Lee Oscar 
Published: July 2009

AbstractChange of actin filament organization at the early stage of cell differentiation directs cell fate commitment of mesenchymal stem cells (MSCs). Thymosin beta‐4 (Tβ4), a major G‐actin sequestering peptide, is known to regulate the cytoskeleton. The study investigated the ways in which Tβ4 regulates cell fate determination in MSCs upon differentiation induction. It was found that Tβ4 decreased F‐actin formation, reduced the F‐actin/G‐actin ratio, and inhibited osteogenic differentiation; such actin reorganization was not associated with the change of Runt‐related transcription factor 2 gene expression during early osteogenic induction. Besides, Tβ4 reciprocally facilitated adipogenic differentiation. Tβ4 treatment was found to up‐regulate gene as well as promote surface expression of adipocyte adhesion molecule during early adipogenic differentiation, which accompanied acceleration of adipocyte phenotypic maturation but was not associated with differential expression of peroxisome proliferator‐activated receptor gamma during the first week of adipogenic induction. In summary, Tβ4 initiated cell fate determination of MSCs through biophysical effects exerted by cytoskeleton reorganization and altered cell‐cell adhesion rather than direct regulation of lineage‐determining transcriptional factors. Such findings suggest that Tβ4, a ubiquitous peptide, may be involved in osteoporosis when its intracellular concentration is elevated. Further investigation of targeting Tβ4 for future osteoporosis treatment is warranted. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:131–138, 2010
An animal model for open femur fracture and osteomyelitis: Part I
Authors: Lindsey Brock A. , Clovis Nina B. , Smith E. Suzanne , Salihu Sydha , Hubbard David F. 
Published: July 2009

AbstractInfection is an everyday problem in orthopaedics and is quite common in open fracture management. To study this process and provide a basis to prevent infection, we developed a model that includes trauma (blunt fracture in the fashion of Bonnarens and Einhorn), surgical stabilization (standardized intramedullary K‐wire fixation), and infection (Staphylococcus aureus inoculum). In this two‐part study, we found that 102 colony‐forming units of inoculum produced an optimal infection rate of 90–100%, which substantially challenged the immune system without overwhelming sepsis. We hypothesized that, in traumatic fractures, there is a specific immunological response that may lead to an increased rate of infection. In Part 2, we demonstrated immunosuppression (decreased Interleukin‐12 levels) at days 6, 10, and 12 after fracture fixation versus nonfractured control groups (p < 0.05). This study describes a rat model of femur factures with osteomyelitis that allows investigation of posttraumatic immunosuppression. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:38–42, 2010
Protonatable Ionenes for Nucleic Acid Complexation
Authors: Ramirez Sean M. , Layman John M. , Long Timothy E. 
Published: July 2009

AbstractNovel tboc‐protected ionenes with $\overline M _{\rm w}$ exceeding 30 kDa were prepared from the step‐growth polymerization of tert‐butyl bis[3‐(dimethylamino)propyl]carbamate and 1,12‐dibromododecane. The protected ionenes yielded pH‐sensitive, protonatable ionenes with pKa ≈ 6.6 for the conjugate acid of the protonated secondary amine. Polyplexes of the protected and deprotected ionenes, whose cytotoxicity for endothelial cells was analyzed using the MTT assay, efficiently complex plasmid DNA. Polyplexes destabilized cellular membranes as revealed using the lactate dehydrogenase assay at high concentrations. The polyplexes were successfully transfected into HBMECs at mass ratios 2, 4, 8, 12, and 16 (polymer/DNA) at polyplex concentrations less than 10 µg · mL−1.magnified image
Sustained and Extended Release with Structural and Activity Recovery of Lysozyme from Complexes with Sodium (Sulfamate Carboxylate) Isoprene/Ethylene Oxide Block Copolymer
Authors: Gao Gao , Yan Yunfeng , Pispas Stergios , Yao Ping 
Published: July 2009

AbstractThe complexation of lysozyme and sodium (sulfamate carboxylate) isoprene/ethylene oxide (SCIEO) at pH = 7.4 and the release of lysozyme from the complexes in the presence of NaCl were investigated. Through electrostatic and hydrophobic interactions, lysozyme and SCIEO form stable complex nanoparticles. The complexation partially disturbs the structure of lysozyme. Some of the hydrophobic residues of lysozyme are exposed to bind with SCIEO. The complexation leads to loss of most of the lysozyme activity. In the presence of NaCl, lysozyme can be released from the complexes. The released lysozyme molecules recover their native structure and activity completely. In the condition of physiological pH and ionic strength, a sustained and extended release of lysozyme was achieved.magnified image
Synthesis of Liquid‐Crystalline Colloids in Nonpolar Media and their Manipulation in Electric Fields
Authors: Haseloh Sönke , Zentel Rudolf 
Published: July 2009

AbstractThe first synthesis of anisotropic liquid‐crystalline colloids in silicone oil by a direct (radical) polymerization of a monomer in THF/silicone oil mixtures with the help of siloxane containing stabilizers is described. The size of the colloids is in the lower µm range and can be adjusted by varying the mixture. The resulting colloids show a bipolar director configuration if they are small (<1.5 µm) and a radial configuration if they are larger. The colloids are sterically stabilized, and, due to the nonpolarity of the solvent, the disturbing effects of migrating ions are excluded and experiments in the electric field can be conducted. Both line formation in DC fields and a periodic switching of the bipolar colloids in AC fields is observed.magnified image
Comparison of High‐Temperature HPLC, CRYSTAF and TREF for the Analysis of the Chemical Composition Distribution of Ethylene‐Vinyl Acetate Copolymers
Authors: Albrecht Andreas , Brüll Robert , Macko Tibor , Malz Frank , Pasch Harald 
Published: July 2009

AbstractThe chemical composition distribution (CCD) is a fundamental molecular parameter of copolymers. High‐temperature interactive liquid chromatography (HT‐HPLC) has recently emerged as a new analytical technique for determination of the CCD of semicrystalline copolymers of ethylene and polar comonomers. With the aim of comparing the results of HT‐HPLC with those from the traditionally used temperature rising elution fractionation (TREF) and crystallization analysis fractionation (CRYSTAF) techniques, three ethylene‐vinyl acetate (EVA) copolymers were fractionated by TREF and the fractions were analyzed by HT‐HPLC. HT‐HPLC‐Fourier transform‐infrared (FT‐IR) spectroscopy showed that individual fractions of different VA‐content coelute in the HPLC. While the separation in TREF and CRYSTAF is mainly the result of the overall effect of alkyl branches and VA‐comonomer units, in HT‐HPLC it is the polar comonomer that selectively contributes to the adsorption. Thus, HT‐HPLC leads to a much more detailed knowledge of the distribution of the structured units; in addition, it saves time.magnified image
Generation of Ag Nanoparticles by PAMAM Dendrimers and their Size Dependence on the Aggregation Behavior of Dendrimers
Authors: Kavitha Manniledam , Parida Manas R. , Prasad Edamana , Vijayan C. , Deshmukh P. C. 
Published: July 2009

AbstractStable silver nanoparticles were generated in aqueous medium by amine, hydroxy and carboxylate terminated poly(amidoamine) (PAMAM) dendrimers in the absence of conventional reducing agents and light irradiation. Mechanistic studies suggest that, in spite of their lower pKa values, tertiary amines present in the dendritic structures act as the reducing agent. Dynamic light scattering and electron microscopic studies reveal that PAMAM dendrimers aggregate in presence of silver ions and the aggregation propensity plays a pivotal role in altering the size and shape of the nanoparticles generated in the dendritic milieu. The formation of metal nanoparticles with uniform size and shape by amine terminated PAMAM dendrimer is attributed to the unique aggregation propensity of amine terminated PAMAM.magnified image
Macroporous Materials from Self‐Assembling Synthetic Cyclic Peptide‐Based Compounds and Deposition of Dipeptide‐Capped Gold Nanoparticles on the Surfaces
Authors: Guha Samit , Banerjee Arindam 
Published: July 2009

AbstractTwo cyclic peptides are separately self‐assembled, one on top of the other, utilizing non‐covalent interactions – mainly intermolecular hydrogen bonding – to form a one‐dimensional array. These one‐dimensional arrays are further self‐assembled to construct macroporous materials. This is shown from TEM, AFM and FE‐SEM analyses. These materials have been used for adsorption and desorption of nitrogen gas. Moreover, they can act as suitable templates for the deposition of dipeptide capped gold nanoparticles on the surfaces of macroporous structures.magnified image
Controlling Orientation and Functionalization in Thin Films of Block Copolymers
Authors: Lee Chansub , Kim Seung Hyun , Russell Thomas P. 
Published: July 2009

AbstractFunctionalizing and controlling nanostructures resulting from block copolymer self‐assembly are key factors in defining their application. In this work, a simple but quite general route to achieve both goals simultaneously is discussed. In thin films of polystyrene‐block‐poly(vinyl pyridine) (PS‐b‐PVP) with small concentrations of a gold salt, the salt is found to complex with the PVP block which leads to an orientation of the microdomains normal to the surface after solvent annealing together with functionalization. By increasing the amount of gold salt, on the other hand, micelles are found to form in solutions leading to a range of different morphologies in the thin films.magnified image
Novel Highly Active Niobium Catalysts for Ring Opening Metathesis Polymerization of Norbornene
Authors: Raspolli Galletti Anna Maria , Pampaloni Guido , D'Alessio Aldo , Patil Yogesh , Renili Filippo , Giaiacopi Simone 
Published: July 2009

AbstractRing‐opening metathesis polymerization (ROMP) of norbornene catalyzed by niobium(V) N,N‐dialkylcarbamates Nb(O2CNR2)5, R = Et (1), Me (2) was studied in the presence of methylaluminoxane (MAO) as a cocatalyst. These novel catalytic systems resulted very active in chlorobenzene: 1 in the presence of methylaluminoxane catalyzes the ROMP of norbornene with the highest activity (29 000 kg of polymer/mol of catalyst × hour) never reported up to now for niobium catalysts. The high productivity appears particularly attractive considering that these precursors are rather cheap and easy to synthesize and to handle. Polynorbornenes were characterized by FT‐IR and NMR spectroscopies and by DSC calorimetry. A new FT‐IR method for the swift determination of the cis/trans content of the polymer is presented.magnified image
Application of WET sequence for the detection of the ligand signals resonating close to water
Authors: Furihata Kazuo , Shimotakahara Sakurako , Shibusawa Yoichi , Tashiro Mitsuru 
Published: July 2009

AbstractAn efficient pulse sequence for observing the ligand signals resonating close to the water signal has been developed by incorporating the WET technique into the saturation transfer difference pulse sequence. Although several pulse sequences have been developed for observing a ligand binding with a protein receptor, the ligand signals resonating close to the water were undetectable owing to the interference of the huge water signal in the samples containing 95% 1H2O. On the point of sample preparation, it is preferable to avoid the solvent exchange in the protein samples. In the proposed pulse sequence, a WET sequence is incorporated for the selective suppression of the water resonance. The efficient water suppression and the clear observation of the bound ligand signals close to the water have been demonstrated using the lysozyme‐glucose complex. Copyright © 2009 John Wiley & Sons, Ltd.
Calibration of a discrete element model for intact rock up to its peak strength
Authors: Wang Yuannian , Tonon Fulvio 
Published: July 2009

AbstractWhen three dimensional, bonded discrete element models (DEMs) are deployed to model intact rock, a basic question is how to determine the micro parameters that control macro properties of the modeled rock. After briefly describing the authors' DEM code, this paper describes algorithms to calibrate the model's micro parameters against standard laboratory tests, such as uniaxial and triaxial tests. Sensitivity analysis is used to identify the deformability micro parameters by obtaining relationships between microscopic and macroscopic deformability properties. The strength model parameters are identified by a global optimization process aimed at minimizing the difference between computed and experimental failure envelopes. When applied to the experimental results of Lac du Bonnet granite, this calibration process produced a good agreement between simulated and experimental results for both deformability and strength properties. Copyright © 2009 John Wiley & Sons, Ltd.
Algebraic multigrid and 4th‐order discrete‐difference equations of incompressible fluid flow
Authors: Webster R. 
Published: July 2009

AbstractThis paper investigates the effectiveness of two different Algebraic Multigrid (AMG) approaches to the solution of 4th‐order discrete‐difference equations for incompressible fluid flow (in this case for a discrete, scalar, stream‐function field). One is based on a classical, algebraic multigrid, method (C‐AMG) the other is based on a smoothed‐aggregation method for 4th‐order problems (SA‐AMG). In the C‐AMG case, the inter‐grid transfer operators are enhanced using Jacobi relaxation. In the SA‐AMG case, they are improved using a constrained energy optimization of the coarse‐grid basis functions. Both approaches are shown to be effective for discretizations based on uniform, structured and unstructured, meshes. They both give good convergence factors that are largely independent of the mesh size/bandwidth. The SA‐AMG approach, however, is more costly both in storage and operations. The Jacobi‐relaxed C‐AMG approach is faster, by a factor of between 2 and 4 for two‐dimensional problems, even though its reduction factors are inferior to those of SA‐AMG.For non‐uniform meshes, the accuracy of this particular discretization degrades from 2nd to 1st order and the convergence factors for both methods then become mesh dependent. Copyright © 2009 John Wiley & Sons, Ltd.
An analytical approximation for solving nonlinear Blasius equation by NHPM
Authors: Aminikhah Hossein 
Published: July 2009

AbstractIn this article, an analytic approximation to the solution of Blasius equation is obtained by using a new modification of homotopy perturbation method. The Blasius equation is a nonlinear ordinary differential equation which arises in the boundary layer flow. The comparison with Howart's numerical solution shows that the new homotopy perturbation method is an effective mathematical method with high accuracy. © 2009 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2010
Assessment of ProteoExtract subcellular fractionation kit reveals limited and incomplete enrichment of nuclear subproteome from frozen liver and heart tissue
Authors: Murray Christopher I. , Barrett Meagan , Van Eyk Jennifer E. 
Published: July 2009

AbstractThe nuclear fraction of the ProteoExtract subcellular fractionation kit was assessed using frozen rat liver and heart tissue. Fractionation was evaluated by Western blot using protein markers for various subcellular compartments and followed up with LC/MS/MS analysis of the nuclear fractions. Of the proteins identified, nuclear proteins were in the minority (less than 15%) and there was poor representation of the various nuclear substructures when compared with liver nuclear isolations using a classical density‐based centrifugation protocol. The ProteoExtract kit demonstrated poor specificity for the nucleus and offers limited promise for proteomics investigations of the nuclear subproteome in frozen tissue samples.
Identification of apolipoproteinA1 reduction in the polycystic kidney by proteomics analysis of the Mxi1‐deficient mouse
Authors: Yoo Kyung Hyun , Kim Yo Na , Lee Min Joo , Seong Je Kyung , Park Jong Hoon 
Published: July 2009

AbstractAutosomal dominant polycystic kidney disease is one of the most common human monogenic diseases in which extensive epithelial‐lined cysts develop in kidney and other organs. Affected kidneys are not only characterized by the formation of cysts, but also by changes associated with the extracellular matrix and interstitial inflammation, which can progress to fibrosis and loss of renal function. Mxi1 protein, which is a c‐myc antagonist, may be essential in controlling cellular growth and differentiation. Previously, multiple tubular cysts were observed in kidney of Mxi1‐deficient mice aged 6 months and more. Presently, 2‐DE and MALDI‐TOF MS was employed to identify the differentially expressed proteins in the kidney. Several proteins were identified, among them, apolipoproteinA1 which is a major component of the high‐density lipoprotein complex and has anti‐inflammation effects, was significantly decreased in the Mxi1‐deficient mouse. We confirm the development of inflammation and renal fibrosis and the expression of extracellular matrix molecules including transforming growth factor were also increased in cystic kidney. These results indicate that expression of proteins related with inflammation and renal fibrosis changes by Mxi1 inactivation in polycystic kidney.