bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular mechanisms of Mn induced neurotoxicity: RONS generation, genotoxicity, and DNA‐damage response
Authors: Bornhorst Julia , Meyer Sören , Weber Till , Böker Carolina , Marschall Talke , Mangerich Aswin , Beneke Sascha , Bürkle Alexander , Schwerdtle Tanja 
Published: March 2013

ScopeIn industrial countries dietary manganese (Mn) intake is well above the estimated average requirement. Moreover, exposure to high Mn levels is known to cause adverse neurological effects in humans, which are yet mechanistically not well understood.Methods and resultsThis study aimed to identify early modes of action of Mn induced toxicity in mammalian brain cells. In primary porcine brain capillary endothelial cells induction of reactive oxygen and nitrogen species was identified as the most sensitive endpoint (≥0.5 μM MnCl2). In cultured human astrocytes MnCl2 was rapidly bioavailable, induced a slight increase of cellular reactive oxygen and nitrogen species levels and a slight decrease of ATP levels (1–100 μM MnCl2), while no genotoxic effects were observed. However, MnCl2 (≥1 μM) efficiently disturbed DNA‐damage‐induced poly(ADP‐ribosyl)ation in human astrocytes, which indicates sensitization of cells to genotoxic treatment. Additionally, we determined Mn levels in infant formula, which are generally massively supplemented with Mn and thus might pose an important source for Mn overexposure.ConclusionThe observed inhibition of DNA‐damage‐induced poly(ADP‐ribosyl)ation in human astrocytes by exposure‐relevant Mn concentrations indicate that in terms of Mn the existing guidelines for infant formula but also drinking water should be critically reconsidered.
Analysis of Slurry‐Phase Co‐Polymerization of Ethylene and 1‐Butene by Ziegler–Natta Catalysts Part 1: Experimental Activity Profiles
Authors: McCoy John T. , Soares Joao B. P. , Rawatlal Randhir 
Published: March 2013

AbstractA rigorous method is developed to extract kinetic parameters describing catalyst activity from experimental polymerization rate profiles for Ziegler–Natta catalysts. The kinetic scheme used correlates the oxidation state with catalyst activity, eliminating the need for multiple site types to describe rate profiles. The method is applied to data from kinetic experiments performed in a lab‐scale semi‐batch reactor. Four parameters are required to describe the activity of the catalyst: the polymerization rate constant and three site transformation rate constants. The model is able to reproduce changes in the rate profiles in response to reactant concentrations. The fits of the model to the data are comparable to those in similar studies.
T‐ and L‐Type Voltage‐Gated Calcium Channels: Their Role in Diabetic Bladder Dysfunction
Authors: Jiang Xiaogang , Luttrell Ian , Chitaley Kanchan , Yang Claire C. 
Published: March 2013

AbstractAimsWe investigated the mechanisms of diabetic bladder dysfunction (BD) through analysis of the roles of L‐ and T‐type voltage‐gated calcium channels (VGCCs), with the ultimate goal of identifying potential drug targets for diabetic BD.MethodsBladder function of db/db (type 2 diabetes) and wild type (Wt) mice was evaluated by behavioral tests and in vivo cystometry. Contractile responses of bladder strips to carbachol were measured with or without pre‐treatment with nifedipine (a L‐type VGCC blocker) or mibefradil (a T‐type VGCC blocker). Furthermore, the effects of mibefradil and nifedipine on the proliferation of human bladder smooth muscle cells (BSMCs) were studied.Resultsdb/db mice had significantly increased voiding frequency, bladder weight, bladder compliance and capacity, and heightened contractile response to carbachol, compared to Wt mice. Nifedipine, but not mibefradil, dramatically suppressed bladder tissue contraction in Wt mice. Whereas nifedipine nearly completely inhibited bladder contraction in db/db mice, mibefradil “normalized” the heightened bladder contractility of db/db mice to the level of Wt mice. In culture, mibefradil, but not nifedipine, inhibited the proliferation of human BSMCs.ConclusionOur results indicate that while L‐type VGCCs play a major role in the contraction of both diabetic and non‐diabetic bladders, T‐type VGCCs are involved in the contraction of diabetic bladders and mediate BSMC proliferation. This study provides support for further investigations on the effect of blockade of T‐type VGCC or combined blockade of both types of VGCCs in the treatment of diabetic BD. Neurourol. Urodynam. 33:147–152, 2014. © 2013 Wiley Periodicals, Inc.
Necessary and sufficient conditions of optimality for an optimal control problem with non‐local boundary conditions and quadratic functional
Authors: Criado‐Aldeanueva F. , Criado F. , Odisehlidze N. , Sanchez J. M. 
Published: March 2013

SUMMARYIn this paper, the optimal control problem with a quadratic functional for Helmholtz equation with non‐local boundary conditions is considered. Necessary and sufficient conditions of optimality are obtained on the basis of which the existence and uniqueness of a solution to the optimal problem are proved. Copyright © 2013 John Wiley & Sons, Ltd.
Influence of surface modification of carbon nanotube on microstructures and properties of polyamide 66/multiwalled carbon nanotube composites
Authors: Qiu Li , Yang Yongzhen , Xu Lihua , Liu Xuguang 
Published: March 2013

AbstractThe melt‐mixing polyamide 66 (PA66) composite samples that incorporated pure, acid‐ and amine‐functionalized multiwalled carbon nanotubes (MWCNTs) were prepared in order to enhance mechanical and frictional properties of PA66 composites. The homogeneous dispersion of amine‐functionalized MWCNTs (D‐MWCNTs) in PA66 matrix was observed from the significantly uniform morphology of tensile fractured surface of the composites. Differential scanning calorimetry measurement indicates that D‐MWCNTs acted as effective nucleation agent for PA66 matrix and the crystallinity of PA66 was increased. The fracture stress and tensile modulus of the composites were significantly improved with the incorporation of D‐MWCNTs, owing to the good dispersion of D‐MWCNTs. Compared with PA66, the PA66 composites with 1.0 wt% D‐MWCNTs were improved considerably in both wear and friction properties owing to the change of the tribological mechanisms. The good dispersion of D‐MWCNTs in PA66 and good interface compatibility between D‐MWCNTs and PA66 favored the formation of a thin layer on the contact surfaces during wear and friction test, which played an important role in reducing wear and friction of the composite and in suppressing the transverse cracks. These results prove the importance of D‐MWCNTs in a positive change of the mechanical and frictional properties of PA66 composites and suggest the applicability prospect of PA66/D‐MWCNTs composites in engineering components.POLYM. COMPOS., 2013. © 2013 Society of Plastics Engineers
Excelling at selling: The charming personality style predicts occupational activities, sales performance, and persuasive competence
Authors: Kazén Miguel , Kuhl Julius , Boermans Sylvie , Koole Sander L. 
Published: March 2013

AbstractThe present research investigates how individual differences in charming personality are related to occupational activities, sales performance, and persuasive competence. Study 1 showed that sales representatives had higher scores on the charming personality style than executive managers. Study 2 showed that the charming personality style predicted actual sales performance among branch managers of a large German insurance company over a period of 2 years; the explicit power motivation served as a mediator in this relation. Finally, Study 3, carried out in a laboratory setting, confirmed the hypothesis that a charming personality is associated with persuasive competence, which suggests that this style is more relevant for sales representatives than for executive managers. The authors conclude that the charming personality style represents an important psychological resource for organizations.
A detailed study on understanding glycopolymer library and Con A interactions
Authors: Gou Yanzi , Geng Jin , Richards Sarah‐Jane , Burns James , Remzi Becer C. , Haddleton D. M. 
Published: March 2013

ABSTRACTSynthetic glycopolymers are important natural oligosaccharides mimics for many biological applications. To develop glycopolymeric drugs and therapeutic agents, factors that control the receptor‐ligand interaction need to be investigated. A library of well‐defined glycopolymers has been prepared by the combination of copper mediated living radical polymerization and CuAAC click reaction via post‐functionalization of alkyne‐containing precursor polymers with different sugar azides. Employing Concanavalin A as the model receptor, we explored the influence of the nature and densities of different sugars residues (mannose, galactose, and glucose) on the stoichiometry of the cluster, the rate of the cluster formation, the inhibitory potency of the glycopolymers, and the stability of the turbidity through quantitative precipitation assays, turbidimetry assays, inhibitory potency assays, and reversal aggregation assays. The diversities of binding properties contributed by different clustering parameters will make it possible to define the structures of the multivalent ligands and densities of binding epitopes tailor‐made for specific functions in the lectin‐ligand interaction. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2588–2597
Rapid Micro‐Scale Patterning of Alkanethiolate Self‐Assembled Monolayers on Au Surface by Atmospheric Micro‐Plasma Stamp
Authors: Weng Chih‐Chiang , Hsueh Jen‐Chih , Liao Jiunn‐Der , Chen Chia‐Hao , Yoshimura Masahiro 
Published: March 2013

AbstractA dielectric barrier discharge‐based micro‐plasma stamp is used to transfer a micro‐scale pattern onto ultra‐thin octadecanethiolate (ODT) self‐assembled monolayers chemically adsorbed on Au (111). The results show that the specified pattern was transferred onto ODT/Au with a distortion rate of less than 1% and no significant changes in the imprint dimensions. The adsorbates formed during plasma treatment or exposure to air affected the transfer of patterns. The wet‐etching rate for the washed and patterned ODT/Au surface increased 1.6‐fold compared to that for the unwashed one. The boundary of the underlaying Au pattern with plasma exposure increased ≈3% due to lateral diffusion of the Au etching solution. magnified image
Microdefects as indicator of steel wire quality
Authors: Vassel Sergei , Pavlova Irina 
Published: March 2013

AbstractThe aim of our work was to create non‐destructive methods of testing steel wire straightness while the wire is being produced. We made a conclusion about the reasons of bending moment appearance. The asymmetry in the density of microcracks on the left and right of the axis of symmetry of the wire leads to the asymmetry of stress in the met al. Also, asymmetry of stress could be the consequence of different mechanical properties of different section of steel wire. This difference in mechanical properties could be the consequence of different concentration of micro defects. Another possible reason of this effect could be the difference in chemical composition of neighbouring wire arrears. So, it was necessary to construct simple devise, which could indicate all that factors. It was suggested to measure the concentration of microcracks by indirect method. The concentration of microcracks affects the number of physical properties of the met al. First of all they are electrical conductivity and magnetic properties. We decide that the simplest solution is to control the asymmetry of stress in the wire by the asymmetry of the magnetic properties of the wire. The devise for such control was developed. This devise contains the magnetizing node, measuring node with magnetic sensors and signal processing unit. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Improved retention of nonvolatile bipolar BiFeO3 resistive memories validated by memristance measurements
Authors: Shuai Yao , Du Nan , Ou Xin , Luo Wenbo , Zhou Shengqiang , Schmidt Oliver G. , Schmidt Heidemarie 
Published: March 2013

AbstractThe transport properties of metal‐insulator‐metal (MIM) capacitor‐like structures have been demonstrated to be sensitive to the metal‐insulator interface. BiFeO3 thin films have been grown on Pt/Ti/SiO2/Si substrates with pulsed laser deposition and RF sputtered Au has been used for the top electrode. As quantified by validated memristance measurements, Ar+ irradiation before deposition of the Au top electrode improved the retention of the BiFeO3 –based MIM structures. In principle it is possible to realize multilevel resistive switching with a very large number of intermediate low resistance states in BiFeO3‐based MIM structures which is mainly limited by the writing bias. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Performance assessment of methods for estimation of fractal dimension from scanning electron microscope images
Authors: Risović Dubravko , Pavlović Živko 
Published: March 2013

SummaryProcessing of gray scale images in order to determine the corresponding fractal dimension is very important due to widespread use of imaging technologies and application of fractal analysis in many areas of science, technology, and medicine. To this end, many methods for estimation of fractal dimension from gray scale images have been developed and routinely used. Unfortunately different methods (dimension estimators) often yield significantly different results in a manner that makes interpretation difficult. Here, we report results of comparative assessment of performance of several most frequently used algorithms/methods for estimation of fractal dimension. To that purpose, we have used scanning electron microscope images of aluminum oxide surfaces with different fractal dimensions. The performance of algorithms/methods was evaluated using the statistical Z‐score approach. The differences between performances of six various methods are discussed and further compared with results obtained by electrochemical impedance spectroscopy on the same samples. The analysis of results shows that the performance of investigated algorithms varies considerably and that systematically erroneous fractal dimensions could be estimated using certain methods. The differential cube counting, triangulation, and box counting algorithms showed satisfactory performance in the whole investigated range of fractal dimensions. Difference statistic is proved to be less reliable generating 4% of unsatisfactory results. The performances of the Power spectrum, Partitioning and EIS were unsatisfactory in 29%, 38%, and 75% of estimations, respectively. The results of this study should be useful and provide guidelines to researchers using/attempting fractal analysis of images obtained by scanning microscopy or atomic force microscopy. SCANNING 35:402–411, 2013. © 2013 Wiley Periodicals, Inc
A Kinetic Study on Carbothermic Reduction of Hematite with Graphite Employing Thermogravimetry and Quadruple Mass Spectrometry
Authors: Jung Sung‐Mo , Yi Sang Ho 
Published: March 2013

AbstractThe reduction of hematite–graphite pellet was investigated from a kinetic viewpoint in the temperature range of 1173–1473 K (900–1200°C). The experimental procedure included thermogravimetric analysis (TGA) for measuring the weight change of the pellet and quadruple mass spectrometry (QMS) for monitoring the compositional change of the product gases. By applying a uniform internal reduction model to the current system, the activation energies for the reduction of Fe3O4 to wustite and for that of wustite to Fe were evaluated to be 91.0 and 25.9 kJ mol−1, respectively. Due to the product gas analyses by QMS, it was observed that the reduction rate of hematite–graphite pellet was accelerated up to the equilibrium concentration of CO determined by the carbon gasification curve. Changeover of reduction mechanism with increasing reduction degree was explained in terms of a schematic diagram based on the results obtained in the current study.
Transplantation of Mesenchymal Stem Cells Promotes Tissue Regeneration in a Glaucoma Model Through Laser-Induced Paracrine Factor Secretion and Progenitor Cell Recruitment
Authors: Manuguerra-GagnÉ Renaud , Boulos Patrick R. , Ammar Ahmed , Leblond François A. , Krosl Gorazd , Pichette Vincent , Lesk Mark R. , Roy Denis-Claude 
Published: March 2013

Abstract
Among bone marrow cells, hematopoietic and mesenchymal components can contribute to repair damaged organs. Such cells are usually used in acute diseases but few options are available for the treatment of chronic disorders. In this study, we have used a laser-induced model of open angle glaucoma (OAG) to evaluate the potential of bone marrow cell populations and the mechanisms involved in tissue repair. In addition, we investigated laser-induced tissue remodeling as a method of targeting effector cells into damaged tissues. We demonstrate that among bone marrow cells, mesenchymal stem cells (MSC) induce trabecular meshwork regeneration. MSC injection into the ocular anterior chamber leads to far more efficient decrease in intraocular pressure (IOP) (p &lt; .001) and healing than hematopoietic cells. This robust effect was attributable to paracrine factors from stressed MSC, as injection of conditioned medium from MSC exposed to low but not to normal oxygen levels resulted in an immediate decrease in IOP. Moreover, MSC and their secreted factors induced reactivation of a progenitor cell pool found in the ciliary body and increased cellular proliferation. Proliferating cells were observed within the chamber angle for at least 1 month. Laser-induced remodeling was able to target MSC to damaged areas with ensuing specific increases in ocular progenitor cells. Thus, our results identify MSC and their secretum as crucial mediators of tissue repair in OAG through reactivation of local neural progenitors. In addition, laser treatment could represent an appealing strategy to promote MSC-mediated progenitor cell recruitment and tissue repair in chronic diseases.
Epigenetic Reprogramming of the Germ Cell Nuclear Factor Gene Is Required for Proper Differentiation of Induced Pluripotent Cells
Authors: Wang Hongran , Wang Xiaohong , Xu Xueping , Zwaka Thomas P. , Cooney Austin J. 
Published: March 2013

Abstract
Somatic cells have been reprogrammed into induced pluripotent stem (iPS) cells that recapitulate the pluripotent nature of embryonic stem (ES) cells. Reduced pluripotency and variable differentiation capacities have hampered progress with this technology for applications in regeneration medicine. We have previously shown that germ cell nuclear factor (Gcnf) is required for the repression of pluripotency genes during ES cell differentiation and embryonic development. Here we report that iPS cell lines, in which the Gcnf gene was properly reprogrammed, allowing expression of Gcnf, repress pluripotency genes during subsequent differentiation. In contrast, iPS clones in which the Gcnf gene was not reprogrammed maintained pluripotency gene expression during differentiation and did not differentiate properly either in vivo or in vitro. These mal-reprogrammed cells recapitulated the phenotype of Gcnf knockout (Gcnf−/−) ES cells. Reintroduction of Gcnf into either the Gcnf negative iPS cells or the Gcnf−/− ES cells rescued repression of Oct4 during differentiation. Our findings establish a key role for Gcnf as a regulator of iPS cell pluripotency gene expression. It also demonstrates that reactivation of the Gcnf gene may serve as a marker to distinguish completely reprogrammed iPS cells from incompletely pluripotent cells, which would make therapeutic use of iPS cells safer and more practical as it would reduce the oncogenic potential of iPS cells. STEM Cells 2013;31:2659–2666
Pim1 Serine/Threonine Kinase Regulates the Number and Functions of Murine Hematopoietic Stem Cells
Authors: An Ningfei , Lin Ying-Wei , Mahajan Sandeep , Kellner Joshua N. , Wang Yong , Li Zihai , Kraft Andrew S. , Kang Yubin 
Published: March 2013

Abstract
The genes and pathways that govern the functions and expansion of hematopoietic stem cells (HSC) are not completely understood. In this study, we investigated the roles of serine/threonine Pim kinases in hematopoiesis in mice. We generated PIM1 transgenic mice (Pim1-Tx) overexpressing human PIM1 driven by vav hematopoietic promoter/regulatory elements. Compared to wild-type littermates, Pim1-Tx mice showed enhanced hematopoiesis as demonstrated by increased numbers of Lin−Sca-1 +c-Kit + (LSK) hematopoietic stem/progenitor cells and cobblestone area forming cells, higher BrdU incorporation in long-term HSC population, and a better ability to reconstitute lethally irradiated mice. We then extended our study using Pim1−/−, Pim2−/−, Pim3−/− single knockout (KO) mice. HSCs from Pim1−/− KO mice showed impaired long-term hematopoietic repopulating capacity in secondary and competitive transplantations. Interestingly, these defects were not observed in HSCs from Pim2−/− or Pim3−/− KO mice. Limiting dilution competitive transplantation assay estimated that the frequency of LSKCD34− HSCs was reduced by approximately 28-fold in Pim1−/− KO mice compared to wild-type littermates. Mechanistic studies demonstrated an important role of Pim1 kinase in regulating HSC cell proliferation and survival. Finally, our polymerase chain reaction (PCR) array and confirmatory real-time PCR (RT-PCR) studies identified several genes including Lef-1, Pax5, and Gata1 in HSCs that were affected by Pim1 deletion. Our data provide the first direct evidence for the important role of Pim1 kinase in the regulation of HSCs. Our study also dissects out the relative role of individual Pim kinase in HSC functions and regulation.
Spatial patterns of hyporheic exchange and biogeochemical cycling around cross‐vane restoration structures: Implications for stream restoration design
Authors: Gordon Ryan P. , Lautz Laura K. , Daniluk Timothy L. 
Published: March 2013

Key Points
In‐stream restoration structures do not create single, deep hyporheic flow cells
Patterns of flux around secondary pools and riffles dominate the streambed area
Hyporheic exchange volumes are ∼0.4% of discharge in restored reaches of 45–55 m
Enhancement of plasmid DNA transformation efficiencies in early stationary‐phase yeast cell cultures
Authors: Tripp Jennifer DeMars , Lilley Jennifer L. , Wood Whitney N. , Lewis L. Kevin 
Published: March 2013

AbstractChemical‐based methods have been developed for transformation of DNA into log‐phase cells of the budding yeast Saccharomyces cerevisiae with high efficiency. Transformation of early stationary‐phase cells, e.g. cells grown in overnight liquid cultures or as colonies on plates, is less efficient than log‐phase cells but is simpler and more adaptable to high‐throughput projects. In this study we have tested different approaches for transformation of early stationary‐phase cell cultures and identified a method utilizing polyethylene glycol (PEG), lithium acetate and dimethyl sulphoxide (DMSO) as the most efficient. Plasmid DNA transformations using this method could be improved modestly by allowing cells to recover from the chemical treatment in rich broth before plating to selective media. Strong increases in transformation efficiencies were observed when cells were treated briefly with dithiothreitol (DTT). Tests using several different yeast strain backgrounds indicated that DTT treatment could enhance transformation efficiencies by up to 40‐fold. Evaluation of multiple parameters affecting the efficiency of the method led to development of an optimized protocol achieving > 50 000 transformants/µg DNA in most backgrounds tested. Copyright © 2013 John Wiley & Sons, Ltd.