bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Intramolecular Transfer to Polymer on Stationary Free Radical Polymerization of Alkyl Acrylates, 4 ‐ Consideration of Penultimate Effect
Authors: Nikitin Anatoly N. , Hutchinson Robin A. 
Published: November 2009

AbstractA penultimate model of acrylate polymerization has been proposed to account for reduced reactivity of radicals formed by monomer addition to midchain radicals. New expressions derived for polymerization rate, number‐average degree of polymerization and branching level are used for a comparative analysis of the penultimate and terminal models. The penultimate model has been also implemented into the simulation program PREDICI to conduct a comparative analysis of time dependencies of conversion, cumulative number‐degree of polymerization and cumulative branching levels calculated for the different models. The calculations show that, depending on radical reactivity ratio si and monomer concentrations, the predictions from the penultimate model significantly deviate from those of the terminal model.magnified image
Properties of Polyvinyl Alcohol Oligomers: A Molecular Dynamics Study
Authors: Rossinsky Eddie , Tarmyshov Konstantin B. , Böhm Michael C. , Müller‐Plathe Florian 
Published: November 2009

AbstractMD studies of liquid isopropyl alcohol and melts of short poly(vinyl alcohol) (PVA) oligomers are described. The specific volume was found to depend inversely on the number N of repeat units. If the chain length is enhanced, the viscosity of the PVA melt increases and the peaks in the radial distribution function become sharper. Additional peaks that appear in melts of PVA chains are of pure intramolecular origin. The calculated radius of gyration was found to depend on the number of formula units via $N^{0.65 \pm 0.03}$. The orientation correlation functions showed that all molecular vectors of PVA melts with chain lengths N = 1, 2, 3 relax completely within a few nanoseconds. The relaxation times for the OH bond vector as obtained via the Kohlrausch‐Williams‐Watts expression showed an exponential dependence on the number of repeat units.magnified image
Nitroxide‐Mediated Radical Polymerization in Dispersed Systems: Compartmentalization and Nitroxide Partitioning
Authors: Zetterlund Per B. 
Published: November 2009

AbstractCompartmentalization and nitroxide partitioning in NMP in dispersed systems have been investigated by modeling and simulations. Compartmentalization comprises the segregation effect on termination and the confined space effect on deactivation. Under certain conditions, it is possible to obtain an improvement in both control and livingness. The particle size threshold for compartmentalization, decreases with any system change that leads to a decrease in the number of propagating radicals and/or nitroxides per particle, and vice versa. There is direct competition between the confined space effect on deactivation and nitroxide exit–the more water‐soluble the nitroxide, the weaker the confined space effect. Nitroxide partitioning leads to an increase in polymerization rate and loss in control/livingness.magnified image
Corneal confocal microscopy: A novel noninvasive means to diagnose neuropathy in patients with fabry disease
Authors: Tavakoli Mitra , Marshall Andrew , Thompson Lorraine , Kenny Margaret , Waldek Stephen , Efron Nathan , Malik Rayaz A. 
Published: November 2009

AbstractNeuropathy is a cause of significant disability in patients with Fabry disease, yet its diagnosis is difficult. In this study we compared the novel noninvasive techniques of corneal confocal microscopy (CCM) to quantify small‐fiber pathology, and non‐contact corneal aesthesiometry (NCCA) to quantify loss of corneal sensation, with established tests of neuropathy in patients with Fabry disease. Ten heterozygous females with Fabry disease not on enzyme replacement therapy (ERT), 6 heterozygous females, 6 hemizygous males on ERT, and 14 age‐matched, healthy volunteers underwent detailed quantification of neuropathic symptoms, neurological deficits, neurophysiology, quantitative sensory testing (QST), NCCA, and CCM. All patients with Fabry disease had significant neuropathic symptoms and an elevated Mainz score. Peroneal nerve amplitude was reduced in all patients and vibration perception threshold was elevated in both male and female patients on ERT. Cold sensation (CS) threshold was significantly reduced in both male and female patients on ERT (P < 0.02), but warm sensation (WS) and heat‐induced pain (HIP) were only significantly increased in males on ERT (P < 0.01). However, corneal sensation assessed with NCCA was significantly reduced in female (P < 0.02) and male (P < 0.04) patients on ERT compared with control subjects. According to CCM, corneal nerve fiber and branch density was significantly reduced in female (P < 0.03) and male (P < 0.02) patients on ERT compared with control subjects. Furthermore, the severity of neuropathic symptoms and the neurological component of the Mainz Severity Score Index correlated significantly with QST and CCM. This study shows that CCM and NCCA provide a novel means to detect early nerve fiber damage and dysfunction, respectively, in patients with Fabry disease. Muscle Nerve, 2009
Vor Ort spektroskopieren
Authors: Brückner Peter , Lerm Steffen 
Published: November 2009

AbstractEin Miniaturspektrometer erfasst bis zu vier Messstellen gleichzeitig und unabhängig voneinander. Damit lassen sich Referenzmessungen durchführen, etwa für Materialuntersuchungen oder in der Lebensmittelüberwachung.
Patentrecht modernisiert
Authors: Seuß Thomas 
Published: November 2009

AbstractDiensterfindungen gehören jetzt automatisch dem Arbeitgeber, wenn er sie nicht ablehnt. Zudem akzeptiert das neue Gesetz E‐Mails zwischen Arbeitgeber und Arbeitnehmer zu Diensterfindungen und regelt Nichtigkeitsberufungsverfahren neu.
Application of NMR in plant metabolomics: techniques, problems and prospects
Authors: Schripsema Jan 
Published: November 2009

AbstractThe present state‐of‐the‐art of NMR in plant metabolomics is reviewed. Attention is paid to the different practical aspects of the application of NMR. The sample preparation, the measurement of the spectrum, quantitative aspects and data analysis are discussed. Each stage has its specific problems, which are pointed out and recommendations are made. Copyright © 2009 John Wiley & Sons, Ltd.
Sample preparation for plant metabolomics
Authors: Kim Hye Kyong , Verpoorte Rob 
Published: November 2009

AbstractSample preparation in plant metabolomics is a fundamental and critical step with important consequences for the accuracy of results. Depending on the analytical tools and the metabolites of interest, sample preparation has to be decided. However, the various methods reported in the literature have many steps in common and consequently the practical considerations concerning the pros and cons are similar. In this review, each step of the sample preparation – harvesting, drying, extraction and purification – will be discussed in detail. Copyright © 2009 John Wiley & Sons, Ltd.
Novel reworkable resins: thermo‐ and photo‐curable di(meth)acrylates
Authors: Matsukawa Daisaku , Okamura Haruyuki , Shirai Masamitsu 
Published: November 2009

AbstractThe aim of the study reported in this paper was to develop new di(meth)acrylates having aromatic units and thermally degradable units in their molecules. It was also the aim to clarify the photo‐curing and degradation properties of the new monomers. Di(meth)acrylates having aromatic units and thermally degradable units were synthesized. As thermally cleavable linkages, tertiary ester moieties were incorporated into the di(meth)acrylates. Three types of processes for curing and degradation of the cured resins were studied: thermal curing and thermal degradation; thermal curing and photodegradation; and photo‐curing and thermal degradation. In the thermal curing and photodegradation process, di(meth)acrylate films containing a thermally induced radical initiator and a photoacid generator (PAG) became insoluble in solvents on heating. The cured films became soluble in solvents after ultraviolet irradiation followed by baking. The re‐dissolution behaviors were strongly affected by the structures of the PAGs. A mechanism for the photo‐ or thermo‐curing and photoassisted thermal degradation was studied using Fourier transform infrared, 1H NMR, thermogravimetric, mass spectrometric and size exclusion chromatographic analyses. Copyright © 2009 Society of Chemical Industry
Symbol nomenclature for glycan representation
Authors: Varki Ajit , Cummings Richard D. , Esko Jeffrey D. , Freeze Hudson H. , Stanley Pamela , Marth Jamey D. , Bertozzi Carolyn R. , Hart Gerald W. , Etzler Marilynn E. 
Published: November 2009

AbstractThe glycan symbol nomenclature proposed by Harvey et al. in these pages has relative advantages and disadvantages. The use of symbols to depict glycans originated from Kornfeld in 1978, was systematized in the First Edition of “Essentials of Glycobiology” and updated for the second edition, with input from relevant organizations such as the Consortium for Functional Glycomics. We also note that >200 illustrations in the second edition have already been published using our nomenclature and are available for download at PubMed.
Streamlined ellipsometry procedure for characterizing physical aging rates of thin polymer films
Authors: Baker Elizabeth A. , Rittigstein Perla , Torkelson John M. , Roth Connie B. 
Published: November 2009

AbstractExisting studies in the research literature showing conflicting changes in physical aging rates with decreasing film thickness in nanoconfined polymer films highlight the need for a single experimental technique to efficiently characterize physical aging rates in thin polymer films of varying chemical structure. To that end, we have developed a streamlined ellipsometry procedure to measure the structural relaxation of thin glassy polymer films. We evaluate different methods of calculating a physical aging rate β from the measured thickness h(t) and index of refraction n(t) data. We present extensive measurements of β as a function of aging temperature and aging time for polystyrene (PS) films supported on silicon, and determine that the physical aging rate β can be easily and reliably determined from β = −1/h0 dh/d(log t), where h0 is the initial measure of the film thickness at an aging time of 10 min. We have also carried out oxygen permeation studies on poly(methyl methacrylate) (PMMA) films from 800 μm down to 190 nm in thickness, and find no change in the permeability with film thickness or physical aging at room temperature for up to 65 days, which suggests that gas permeation may be insensitive to physical aging in such low free volume polymers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2509–2519, 2009
Effect of nanoclay on relaxation of poly(vinylidene fluoride) nanocomposites
Authors: Yu Lei , Cebe Peggy 
Published: November 2009

AbstractThe effect of Lucentite™ STN nanoclay on the relaxation behavior of poly(vinylidene fluoride) (PVDF) nanocomposites was investigated using dielectric relaxation spectroscopy (DRS) and wide‐ and small‐angle X‐ray scattering. Lucentite™ STN is a synthetic nanoclay based on hectorite structure containing an organic modifier between the hectorite layers. The addition of this nanoclay to PVDF results in preferential formation of the beta‐crystallographic phase. When the STN content increased to 5% and 10%, only the beta‐phase was observed. Bragg long period and lamellar thickness both decrease with STN addition. The relaxation rates for processes termedαa(glass transition, related to polymer chain motions in the amorphous regions) andαc(related to polymer chain motions in the crystalline regions and fold surfaces) can be described either with the Vogel‐Fulcher‐Tamman equation or with Arrhenius behavior, respectively. DRS shows that theαarelaxation rate increases with the concentration of STN because of the reduction of intermolecular correlations between the polymer chains, caused by the presence of layered silicate nanoclay particles, which serve to segregate polymer chains in the amorphous regions. Comparing samples with beta‐crystal phase dominant, the relaxation rate for theαcrelaxation also increases with concentration of STN in all nanocomposite samples. Dielectric properties at low frequencies are dominated by the dc conductivity, and as more STN is added, the conductivity increases rapidly. The addition of 10% STN makes the dc conductivity increase by almost four decades when compared with neat PVDF. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2520–2532, 2009
Characteristics of the Deposition Rate per Unit Power on Pulsed‐DC Magnetron Sputtering Source
Authors: An Sanghyuk , In Junghwan , Chang Hongyoung 
Published: November 2009

AbstractThe deposition rate per unit power in a pulsed‐DC magnetron sputtering source was examined according to the target material, average power, and duty cycle. In a short duty cycle condition, the deposition rate per unit power of Ti and Cu decreased with increasing the pulse power, while that of Al and Ti in a long duty cycle condition did not change in relation to the pulse power. These results can be explained in terms of the characteristics of the sputtering yield in relation to the bombarding ion energy. Based on these results, a pulse voltage with two steps is proposed in order to increase the deposition rate per unit power.magnified image
Plasma Polymer Coatings to Support Mesenchymal Stem Cell Adhesion, Growth and Differentiation on Variable Stiffness Silicone Elastomers
Authors: Colley Helen E. , Mishra Gautam , Scutt Andrew M. , McArthur Sally L. 
Published: November 2009

AbstractThe mechanical properties of the underlying substratum have previously been shown to affect a number of cellular processes including locomotion, proliferation and differentiation. Although polyacrylamide is the most studied variable‐stiffness substrate, silicone elastomers offer a more physiologically relevant range of moduli. Here, we employ plasma polymerisation to apply an acid‐containing polymer thin film to silicone elastomer substrates. This simple one‐step surface modification process renders the surfaces hydrophilic and does not require the introduction of extracellular matrix (ECM) proteins commonly used as modification agents to support cell attachment. Contact angle and XPS analysis demonstrates that the coating chemistry is consistent across all of the materials and critically, we show that the addition of this coating does not alter the underlying mechanical properties of the elastomer. The surface modification supports mesenchymal stem cell (MSC) adhesion to a level that is comparable to that seen for tissue culture polystyrene (TCPS). When used as a variable‐stiffness substrate to study cell behaviour we demonstrate that MSC proliferation is unaltered but osteogenic differentiation varies with substrate stiffness.magnified image
The conserved active site tryptophan of thioredoxin has no effect on its redox properties
Authors: Roos Goedele , Geerlings Paul , Messens Joris 
Published: November 2009

AbstractIn Staphylococcus aureus thioredoxin (Trx) it has been shown that mutation of the conserved active site tryptophan residue (Trp28) has a large effect on the protein stability, on the pKa of the nucleophilic cysteine and on the redox potential. Since these effects can either be due to the partially unfolding of the Trp28Ala mutant or to the absence of the indole side chain of Trp28 as possible interaction partner for the active site cysteines, the origin of the experimentally observed effects is not known and is beyond experimental approach. With theoretical pKa and density functional theory reactivity analysis on model systems where Trp28 has been replaced by an alanine within the structural environment of Trx it is shown that Trp28 does not affect the redox parameters of Trx. As such, the experimentally observed redox effects of the Trx W28A mutant might be due to structural changes induced by partial unfolding.
Structural differences between apolipoprotein E3 and E4 as measured by 19F NMR
Authors: Garai Kanchan , Mustafi Sourajit M. , Baban Berevan , Frieden Carl 
Published: November 2009

AbstractThe apolipoprotein E family contains three major isoforms (ApoE4, E3, and E2) that are directly involved with lipoprotein metabolism and cholesterol transport. ApoE3 and apoE4 differ in only a single amino acid with an arginine in apoE4 changed to a cysteine at position 112 in apoE3. Yet only apoE4 is recognized as a risk factor for Alzheimer's disease. Here we used 19F NMR to examine structural differences between apoE4 and apoE3 and the effect of the C‐terminal domain on the N‐terminal domain. After incorporation of 5‐19F‐tryptophan the 1D 19F NMR spectra were compared for the N‐terminal domain and for the full length proteins. The NMR spectra of the N‐terminal region (residues 1–191) are reasonably well resolved while those of the full length wild‐type proteins are broad and ill‐defined suggesting considerable conformational heterogeneity. At least four of the seven tryptophan residues in the wild type protein appear to be solvent exposed. NMR spectra of the wild‐type proteins were compared to apoE containing four mutations in the C‐terminal region that gives rise to a monomeric form either of apoE3 under native conditions (Zhang et al., Biochemistry 2007; 46: 10722–10732) or apoE4 in the presence of 1 M urea. For either wild‐type or mutant proteins the differences in tryptophan resonances in the N‐terminal region of the protein suggest structural differences between apoE3 and apoE4. We conclude that these differences occur both as a consequence of the Arg158Cys mutation and as a consequence of the interaction with the C‐terminal domain.
Immunosuppressive CD14+HLA‐DRlow/− monocytes in prostate cancer
Authors: Vuk‐Pavlović Stanimir , Bulur Peggy A. , Lin Yi , Qin Rui , Szumlanski Carol L. , Zhao Xinghua , Dietz Allan B. 
Published: November 2009

AbstractOBJECTIVETo determine if the levels of circulating myeloid‐derived suppressor cells increase with progression of prostate cancer (PCa); to determine if such cells could contribute to the relative inefficiency of PCa immunotherapy.MATERIALS AND METHODSWe analyzed peripheral blood mononuclear cells isolated from untreated PCa patients (uPCa; N = 18; mean age ± SD: 72.1 ± 6.9 years), tPCa (N = 22; 72.8 ± 9.8 years) and age matched controls (AMC; N = 12; 68.8 ± 7.5 years). We quantified surface marker phenotype, differentiation potential, effects on T cell proliferation and intracellular cytokines.RESULTSWe observed an unexpectedly high percentage of a type of myeloid‐derived suppressor cells, CD14+HLA‐DRlow/− monocytes, in tPCa (30.7 ± 15.0% of CD14+ cells) relative to AMC (4.1 ± 6.5%, P < 0.0001) and uPCa (10.6 ± 14.3%, P = 0.0001). The levels of CD14+ HLA‐DRlow/− cells were significantly correlated with circulating PSA levels and treatment with LHRH‐agonist leuprolide in combination with either an antiandrogen or dexamethasone. Monocytes from tPCa inhibited autologous T cell proliferation statistically significantly more effectively than AMC monocytes and were defective in their ability to differentiate into phenotypically mature dendritic cells. Isolated CD14+HLA‐DRlow/− cells expressed higher levels of intracellular interleukin‐10 and suppressed T cell proliferation more effectively than isolated CD14+HLA‐DR+ cells.CONCLUSIONSThis is the first report of CD14+ cells exhibiting reduced expression of HLA‐DR molecules in PCa patients. These cells suppress immune cell function in vitro and, plausibly, in vivo, a finding that must be factored into the design of immunotherapy protocols for PCa patients. Prostate 70: 443–455, 2010. © 2009 Wiley‐Liss, Inc.
Monocyte chemotactic protein‐1 (MCP‐1/CCL2) is associated with prostatic growth dysregulation and benign prostatic hyperplasia
Authors: Fujita Kazutoshi , Ewing Charles M. , Getzenberg Robert H. , Parsons J. Kellogg , Isaacs William B. , Pavlovich Christian P. 
Published: November 2009

AbstractBACKGROUNDChronic inflammation is commonly observed in benign prostate hyperplasia (BPH), and prostate tissue often contains increased inflammatory infiltrates, including T cells and macrophages. Cytokines are not only key mediators of inflammation but may also play important roles in the initiation and progression of BPH.METHODSIn order to determine what cytokines might be involved in prostatic enlargement, expressed prostatic secretions (EPS) from ex vivo prostates were analyzed by human cytokine antibody microarray and ELISA. Prostate epithelial cells (PrEC) and prostate stromal cells (PrSC) were used for ELISA, proliferation, and Western blot assays.RESULTSMonocyte chemotactic protein‐1 (MCP‐1/CCL2) was one of the most elevated proteins in secretions from large prostate glands. PrSC were found to secrete MCP‐1; Western blotting showed that both PrSC and PrEC express the MCP‐1 receptor CCR2 which by RT‐PCR was the CCR2b isoform. Proliferation assays showed that MCP‐1 stimulates the proliferation of PrEC, but not PrSC, and that a specific MCP‐1 antagonist (RS102895) suppressed this effect. Conditioned medium from PrSC stimulated the proliferation of PrEC as well, an effect completely inhibited by both RS102895 and a neutralizing anti‐MCP‐1 monoclonal antibody. The inflammatory cytokines interleukin (IL)‐1β, interferon‐γ, and IL‐2 enhanced the secretion of MCP‐1 from PrEC and PrSC. In addition, MCP‐1 levels in EPS correlated with mRNA levels of the macrophage marker CD68 in the same secretions.CONCLUSIONSThe cytokine MCP‐1, of apparent prostatic stromal cell origin, may play an important role in prostatic enlargement and BPH, and is a candidate biomarker for these pathologic processes. Prostate 70: 473–481, 2010. © 2009 Wiley‐Liss, Inc.
Vacancy‐patterned graphene: A meta‐material for spintronics
Authors: Artyukhov Vasilii I. , Chernozatonskii Leonid A. 
Published: November 2009

AbstractWe use density functional theory to explore the implications of atomically precise patterning of graphene with monovacancies. We show that one‐dimensional tracks of vacancies can be used to turn graphene into a magnetic meta‐material with properties that can be flexibly varied by external factors such as doping. Chemical functionalization by H or F atoms does not disrupt the magnetic structure of the material; moreover, controlled passivation with appropriate chemical species could be used as an additional means to tailor the properties of the meta‐material. This leads us to propose patterning of graphene with vacancy tracks as a possible route towards integrated spintronic circuits on single graphene sheets. Several possible pathways towards practical fabrication of such systems are discussed.
magnified imageSpin density in graphene with periodically arranged monovacancies.