bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vivo severe corrosion and hydrogen embrittlement of retrieved modular body titanium alloy hip‐implants
Authors: Rodrigues Danieli C. , Urban Robert M. , Jacobs Joshua J. , Gilbert Jeremy L. 
Published: August 2008

AbstractTitanium alloys are widely used in total‐joint replacements due to a combination of outstanding mechanical properties, biocompatibility, passivity, and corrosion resistance. Nevertheless, retrieval studies have pointed out that these materials can be subjected to localized or general corrosion in modular interfaces when mechanical abrasion of the oxide film (fretting) occurs. Modularity adds large crevice environments, which are subject to micromotion between contacting interfaces and differential aeration of the surface. Titanium alloys are also known to be susceptible to hydrogen absorption, which can induce precipitation of hydrides and subsequent brittle failure. In this work, the surface of three designs of retrieved hip‐implants with Ti‐6Al‐4V/Ti‐6Al‐4V modular taper interfaces in the stem were investigated for evidence of severe corrosion and precipitation of brittle hydrides during fretting‐crevice corrosion in the modular connections. The devices were retrieved from patients and studied by means of scanning electron microscopy (SEM), X‐ray diffraction (XRD), and chemical analysis. The surface qualitative investigation revealed severe corrosion attack in the mating interfaces with evidence of etching, pitting, delamination, and surface cracking. In vivo hydrogen embrittlement was shown to be a mechanism of degradation in modular connections resulting from electrochemical reactions induced in the crevice environment of the tapers during fretting‐crevice corrosion. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The mechanism of double proton transfer in dimers of uracil and 2‐thiouracil—The reaction force perspective
Authors: Lamsabhi Al Mokhtar , Mó Otilia , Gutiérrez‐Oliva Soledad , Pérez Patricia , Toro‐Labbé Alejandro , Yáñez Manuel 
Published: August 2008

AbstractThe intermolecular double proton transfer in dimers of uracil and 2‐thiouracil is studied through density functional theory calculations. The reaction force framework provides the basis for characterizing the mechanism that in all cases has been associated to a dynamic balance between polarization and charge transfer effects. It has been found that the barriers for proton transfer depend upon the nature of the acceptor atoms and its position within the seminal monomer. Actually, the change in the nature of the hydrogen bonds connecting the two monomers along the reaction coordinate may favor or disfavor the double‐proton transfer. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2009
Comparison of glycolysis and oxidative phosphorylation as energy sources for mammalian sperm motility, using the combination of fluorescence imaging, laser tweezers, and real‐time automated tracking and trapping
Authors: Nascimento Jaclyn M. , Shi Linda Z. , Tam James , Chandsawangbhuwana Charlie , Durrant Barbara , Botvinick Elliot L. , Berns Michael W. 
Published: August 2008

AbstractThe combination of laser tweezers, fluorescent imaging, and real‐time automated tracking and trapping (RATTS) can measure sperm swimming speed and swimming force simultaneously with mitochondrial membrane potential (MMP). This approach is used to study the roles of two sources of ATP in sperm motility: oxidative phosphorylation, which occurs in the mitochondria located in the sperm midpiece and glycolysis, which occurs along the length of the sperm tail (flagellum). The relationships between (a) swimming speed and MMP and (b) swimming force and MMP are studied in dog and human sperm. The effects of glucose, oxidative phosphorylation inhibitors and glycolytic inhibitors on human sperm motility are examined. The results indicate that oxidative phosphorylation does contribute some ATP for human sperm motility, but not enough to sustain high motility. The glycolytic pathway is shown to be a primary source of energy for human sperm motility. J. Cell. Physiol. 217: 745–751, 2008. © 2008 Wiley‐Liss, Inc.
Phage display screening for peptidic chitinase inhibitors
Authors: Petter Cordula , Scholz Christa , Wessner Helga , Hansen Gerd , Henklein Peter , Watanabe Takeshi , Höhne Wolfgang 
Published: August 2008

AbstractA phage display library with disulfide‐cyclized peptides was screened for peptides binding to chitinases from Serratia marcescens. One of those peptides was found to efficiently inhibit chitinase A and two others were inhibitors of chitinase B. Complete substitutional analysis of all three peptides using cellulose‐bound peptide spot synthesis revealed key interaction positions and allowed optimization of the chitinase B inhibitory peptides towards higher affinity, with inhibitory constants in the lower nanomolar range. Inhibition by all peptides proved to be competitive and highly specific for the chitinase used to select them, as shown with a series of chitinases from different organisms. Copyright © 2008 John Wiley & Sons, Ltd.
Transcriptional profile of primary astrocytes expressing ALS‐linked mutant SOD1
Authors: Vargas Marcelo R. , Pehar Mariana , Díaz‐Amarilla Pablo J. , Beckman Joseph S. , Barbeito Luis 
Published: August 2008

AbstractAmyotrophic lateral sclerosis (ALS) is caused by the progressive degeneration of motor neurons. Mutations in the Cu/Zn superoxide dismutase (SOD1) are found in approximately 20% of patients with familial ALS. Mutant SOD1 causes motor neuron death through an acquired toxic property. Although the molecular mechanism underlying this toxic gain‐of‐function remains unknown, evidence support the role of mutant SOD1 expression in nonneuronal cells in shaping motor neuron degeneration. We have previously found that in contrast to nontransgenic cells, SOD1G93A‐expressing astrocytes induced apoptosis of cocultured motor neurons. This prompted us to investigate whether the effect on motor neuron survival was related to a change in the gene expression profile. Through high‐density oligonucleotide microarrays, we found changes in the expression of genes involved in transcription, signaling, cell proliferation, extracellular matrix synthesis, response to stress, and steroid and lipid metabolism. The most up‐regulated gene was decorin (Dcn), a small multifunctional extracellular proteoglycan. Down‐regulated genes included the insulin‐like growth factor‐1 receptor (Igf‐1r) and the RNA binding protein ROD1. Rod1 was also found down‐regulated in purified motor neurons expressing SOD1G93A. Changes in the expression of Dcn, Igf‐1r, and Rod1 were found in the spinal cord of asymptomatic animals, suggesting these changes occur before overt neuronal degeneration and potentially influence astrocyte–motor neuron interaction in the course of the disease. The astrocyte‐specific gene expression profile might contribute to the identification of possible candidates for cell type‐specific therapies in ALS. © 2008 Wiley‐Liss, Inc.
Intracerebral transplantation of neural stem cells combined with trehalose ingestion alleviates pathology in a mouse model of Huntington's disease
Authors: Yang Chia‐Ron , Yu Robert K. 
Published: August 2008

AbstractThe present investigation examined the neuroprotective benefits for combined trehalose administration with C17.2 neural stem cell transplantation in a transgenic mouse model of Huntington's disease (HD), R6/2. C17.2 neural stem cells have the potential of differentiating into a neuronal phenotype in vitro and have been shown to be effective in the treatment of a variety of lysosomal lipid storage disorders in the nervous system. In this study, we transplanted these cells into the lateral ventricle of R6/2 transgenic mice in order to examine the efficacy of using these cells for correcting the accumulated polyglutamine storage materials in HD. To improve efficacy, animals were fed with a diet rich in trehalose, which has been shown to be beneficial to retard aggregate formation. The combined treatment strategy not only decreased ubiquitin‐positive aggregation in striatum, alleviated polyglutamine aggregation formation, and reduced striatal volume, but also extended life span in the R6/2 animal model. Behavioral evaluation showed that the combination treatment improved motor function. Statistical analysis revealed that the combination treatment was more effective than treatment with trehalose alone on the basis of the above biochemical and behavioral criteria. This study provides a strong a basis for further developing an effective therapeutic strategy for HD. © 2008 Wiley‐Liss, Inc.
Evidence for disruption of sphingolipid metabolism in schizophrenia
Authors: Narayan Sujatha , Head Steven R. , Gilmartin Timothy J. , Dean Brian , Thomas Elizabeth A. 
Published: August 2008

AbstractAs the field of glycobiology grows, important roles for glycolipids and glycoproteins in neurological disorders are being increasingly appreciated. However, few studies have explored the involvement of these molecules in the pathology of psychiatric illnesses. We investigated molecular differences related to glycobiology in subjects with schizophrenia by analyzing gene expression profiles using a focused glycogene chip, a custom‐designed oligonucleotide array containing genes encoding proteins related to glycobiology, including glycosyltransferases, carbohydrate‐binding proteins, proteoglycans, and adhesion molecules. We measured expression profiles in prefrontal cortical (BA46) samples from schizophrenic subjects and matched controls. We find differential expression of genes particularly related to glycosphingolipid/sphingolipid metabolism and N‐ and O‐linked glycan biosynthesis in subjects with schizophrenia. Expression decreases of seven genes associated with these pathways, UGT8, SGPP1, GALC, B4GALT6, SPTLC2, ASAH1, and GAL3ST1, were validated by quantitative PCR in schizophrenic subjects with short‐term illness. Only one of these genes, SPTLC2, showed differential expression in chronic schizophrenic subjects, although an increase in expression was observed. Covariate analysis showed that the expression of five of these genes was significantly positively correlated with age in schizophrenic, but not control, subjects. These changing patterns of expression could represent an adaptive response to pathology with disease progression or a compensatory effect of antipsychotic medication, although no significant correlations between gene expression levels and drug doses were observed. Disruption of sphingolipid metabolism early in illness could result in widespread downstream effects encompassing diverse pathological deficits already described in schizophrenia, especially those involving myelination and oligodendrocyte function; hence, this system may represent an important link in schizophrenia pathology. © 2008 Wiley‐Liss, Inc.
Effect of plant cultivation methods on content of major and trace elements in foodstuffs and retention in rats
Authors: Kristensen Mette , Østergaard Lars F , Halekoh Ulrich , Jørgensen Henry , Lauridsen Charlotte , Brandt Kirsten , Bügel Susanne 
Published: August 2008

AbstractBACKGROUND: Many consumers perceive organic foods as more nutritious than conventional foods. However, the existing evidence is insufficient to support or refute this belief. The purpose of the present study was to investigate the effect of three different model cultivation systems on selected major and trace element contents of dried foodstuffs (carrots, kale, peas, potatoes and apples) grown in two consecutive years, as well as mineral retention determined in 36 rats (second generation in a multi‐generation study) fed diets based on these foodstuffs from one year.RESULTS: Overall, there was no evident trend towards differences in element content of foodstuffs or diets due to the use of different cultivation systems, and differences between harvest years exceeded those seen between cultivation methods. Also, no significant differences in the retention of elements in rats fed diets derived from different cultivation systems were seen, since higher intake resulted in correspondingly higher excretion.CONCLUSION: This study does not support the belief that organically grown foodstuffs generally contain more major and trace elements than conventionally grown foodstuffs, nor does there appear to be an effect on the bioavailability of major and trace minerals in rats. Copyright © 2008 Society of Chemical Industry
Timing of sentinel lymph node biopsy in patients receiving neoadjuvant chemotherapy for breast cancer
Authors: Papa Moshe Zvi , Zippel Douglas , Kaufman Bella , Shimon‐Paluch Shani , Yosepovich Ady , Oberman Bernice , Sadetzki Siegal 
Published: August 2008

AbstractObjectiveTo address optimal timing of sentinel lymph node biopsy (SLNB) in breast cancer patients undergoing neoadjuvant treatment.MethodsThe study population included 117 patients with locally advanced cancer with clinically negative nodes treated with primary chemotherapy. Group 1 underwent SLNB and completion axillary lymph node dissection (ALND) in conjunction with lumpectomy/mastectomy, after neoadjuvant treatment (n = 31). Group 2 underwent SLNB followed by neoadjuvant therapy and subsequently surgery and completion of ALNDs (n = 58). Group 3 was treated using the same sequence as group 2, however, completion ALND was performed only for patients with positive sentinel lymph nodes (SLNs) (n = 28).ResultsSLN identification was lowest in group 1 compared to groups 2 and 3 (87% and 98.8% respectively; P = <0.05). The highest false negative rate was in group 1 (15.8% compared with 0% in group 2).ConclusionNeoadjuvant treatment lowers the SLN identification rate, possibly due to fibrosis within the axilla, and increases the false negative rate due to downstaging. SLN biopsy prior to chemotherapy could give a more accurate evaluation of axillary status, unaffected by any previous therapeutic intervention. J. Surg. Oncol. © 2008 Wiley‐Liss, Inc.
Oligonucleotide Nanostructured Surfaces: Effect on Escherichia coli Curli Expression
Authors: Cottenye Nicolas , Teixeira Francisco , Ponche Arnaud , Reiter Günter , Anselme Karine , Meier Wolfgang , Ploux Lydie , Vebert‐Nardin Corinne 
Published: August 2008

AbstractOligonucleotide model surfaces allowing independent variation of topography and chemical composition were designed to study the adhesion and biofilm growth of E.coli. Surfaces were produced by covalent binding of oligonucleotides and immobilization of nucleotide‐based vesicles. Their properties were confirmed through a combination of fluorescence microscopy, XPS, ellipsometry, AFM and wettability studies at each step of the process. These surfaces were then used to study the response of three different strains of E.coli quantified in a static biofilm growth mode. This study led to convincing evidence that oligonucleotide‐modified surfaces, independent of the topographical feature used in this study, enhanced curli expression without an increase in the number of adherent bacteria.magnified image
Cellular Adhesion, Proliferation and Viability on Conducting Polymer Substrates
Authors: del Valle Luis J. , Estrany Francesc , Armelin Elaine , Oliver Ramón , Alemán Carlos 
Published: August 2008

AbstractThis work reports a comprehensive study about cell adhesion and proliferation on the surface of different electroactive substrates formed by π‐conjugated polymers. Biological assays were performed considering four different cellular lines: two epithelial and two fibroblasts. On the other hand, the electroactivity of the three conducting systems was determined in physiological conditions. Results indicate that the three substrates behave as a cellular matrix, even though compatibility with cells is larger for PPy and the 3‐layered system. Furthermore, the three polymeric systems are electro‐compatible with the cellular monolayers.magnified image
Corrosion mechanisms in the wood industry, especially caused by tannins
Authors: Winkelmann H. , Badisch E. , Roy M. , Danninger H. 
Published: August 2008

AbstractIn order to improve the lifetime of cutting knives in the wood processing industry, a study has been undertaken to find out which wear process is primarily responsible for the reduction of the lifetime of steel blades. The examination of damaged surfaces of the cutting tools reveals mechanical damage at the cutting edges on one hand, but on the other hand pitting corrosion can be detected. It turned out that the corrosion impact reduces the lifetime of the cutting tools more than the mechanical loading, because a mechanically damaged steel blade can easily be repaired through grinding. But once the blade is subjected to pitting corrosion, it becomes useless because whenever the blade is reground, new holes due to pitting corrosion come to the surface again. Further investigations showed that the corrosiveness of different wood types is responsible for a major part of the damage, and that different woods have a different corrosive impact. One important goal of the present investigation is to learn more about the corrosive agents of different woods. It is revealed that tannin, a water‐soluble acid, which can be found in all woods in different concentrations, is responsible for the main part of the corrosive attack. In view of the above, the corrosion mechanism of steel blades caused by tannin is analyzed. During the cutting processes in the industry the blade temperature is increased. Thus, it is aimed to evaluate the influence of higher temperatures on tannin and the pH value of the acid. It is also revealed that the additional mechanical stress has an important influence on the corrosion process. The investigation could satisfactorily show the lowering of the pH value of tannin acid at higher temperature, which leads to increased corrosion. It is also revealed that the additional mechanical stress causes off stripping of tannin–Fe complexes from the steel surface, there the steel was not able to build a protective layer yet. That also leads to a further increase in corrosion.
Structure and Mechanical Properties of Poly(lactic acid) Filled with (Starch nanocrystal)‐graft‐poly(ε‐caprolactone)
Authors: Yu Jiahui , Ai Fujin , Dufresne Alain , Gao Shanjun , Huang Jin , Chang Peter R. 
Published: August 2008

AbstractPoly(ε‐caprolactone) (PCL) was grafted to the surface of starch nanocrystals (StN) via microwave‐assisted ROP. The resultant nanoparticles were then incorporated into a poly(lactic acid) matrix to produce fully‐biodegradable nanocomposites with good mechanical properties. A loading level of 5 wt.‐% StN‐g‐PCL resulted in simultaneous enhancements of strength and elongation. The StN‐g‐PCL self‐aggregated as rubbery microparticles to enhance the elongation by ca. 10‐fold over that of neat PLA. Meanwhile, the grafted PCL chains were miscible with PLA and formed a stress‐transferring interface to the StN, providing a reinforcing function.magnified image
Hydrated Clay for Catalyst Removal in Copper Mediated Atom Transfer Radical Polymerization
Authors: Munirasu Selvaraj , Deshpande Ashwini , Baskaran Durairaj 
Published: August 2008

AbstractA simple method has been described to remove catalyst from the copper mediated atom transfer radical polymerization (ATRP) of benzyl methacrylate and methyl methacrylate in anisole at 25 °C using hydrated natural clay (sodium montmorillonite, Na‐clay). The method consists of (1) addition of hydrated clay (CuI/clay ≈ 5 wt.‐%) either during or after the polymerization, (2) oxidation of catalyst complex by exposing the terminated reaction mixture in air, and (3) filtration to obtain catalyst free polymer solution. A strong coordination of CuBr‐ligand complex onto hydrated clay (10 wt.‐% < H2O/clay < 30 wt.‐%) upon oxidation resulted in polymers with no or insignificant residual catalyst (<1.74 ppm), as determined by UV‐vis and atomic absorption spectroscopy. The recovered clay exhibited expanded intercalary layers and absence of polymer within it.magnified image
Micellization of a Siloxane‐Based Segmented Copolymer in Organic Solvents and its Use as a Tool for Metal Complex Nanoparticles
Authors: Racles Carmen , Cazacu Maria , Ioanid Aurelia , Vlad Angelica 
Published: August 2008

AbstractThe micellization of a polysiloxane‐ketimine has been studied in solvents of different polarity, i.e., dimethylformamide (DMF) and toluene. The critical micelle concentration was determined from surface tension measurements ‐in DMF‐, and from viscosity variation with concentration. Metal complex nanoparticles have been synthesized from this macromolecular ligand in DMF and in toluene, using the formed micelles as templates. Spectroscopic data (IR and UV‐vis) confirmed the metal complexation. TEM observations revealed the formation of nanoparticles with different morphologies, which were consistent with the assumed conformation of the ligand in solutions of the two selective solvents.magnified image
Reductive Formation of Isospecific Ti Dinuclear Species on a MgCl2 (110) Surface in Heterogeneous Ziegler‐Natta Catalysts
Authors: Taniike Toshiaki , Terano Minoru 
Published: August 2008

AbstractDinucleation of TiCl4 on the MgCl2 (100) surface has been conventionally believed as the origin of the stereospecificity of heterogeneous Ziegler‐Natta catalysts for propylene polymerization, while the MgCl2 (110) surface has been regarded as non‐stereoselective in the absence of organic donors. Based on periodic density functional calculations, we propose a new isospecific Ti dinuclear species on the MgCl2 (110) surface, which is formed as a result of reduction of Ti from 4+ to 3+. The new species closely resembles the dinuclear species on the (100) surface, but two Ti ions are obliquely stacked along the (110) surface through Cl bridges. The results address the importance of the reduction and re‐distribution of surface Ti species after contacting with cocatalysts in considering the origin of the stereospecificity.magnified image
Selective HOESY experiments for stereochemical determinations
Authors: Yemloul Mehdi , Bouguet‐Bonnet Sabine , Ba Lalla Aïcha , Kirsch Gilbert , Canet Daniel 
Published: August 2008

AbstractHeteronuclear Overhauser effect spectroscopy (HOESY) is a powerful method for tracking geometrical proximities between two heteronuclei (for instance, 1H and 13C, as this will be the case here). The method is based on cross‐relaxation arising from dipolar interactions. Sensitivity permitting, it is applied in the 2D mode yielding all spatial correlations in a single experiment. Whenever sensitivity is not sufficient, it can be applied in the one‐dimensional mode by selectively inverting one particular proton. In that case, it yields, from the carbon‐13 spectrum, remote spatial correlations. The method has been employed here for the discrimination between two possible E or Z isomers in a medium‐size molecule. Copyright © 2008 John Wiley & Sons, Ltd.