bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Halo‐Enol Phostones by Using DMAP‐Catalyzed Halocyclization of Alkynylphosphonic Monoesters
Authors: Huang Jiale , Wang Haiyang , Peng Ai‐Yun 
Published: November 2014

AbstractA new class of non‐benzo halo‐enol phostones was synthesized by using a DMAP‐catalyzed [DMAP = 4‐(dimethylamino)pyridine] halocyclization reaction of 4‐pentynylphosphonic monoesters with N‐bromosuccinimide (NBS) or N‐iodosuccinimide (NIS) in CHCl3 at room temperature. DMAP was critical to the reaction system, as it greatly improved the yields of the desired products. The reaction showed high regioselectivity for six‐membered ring products that were formed by a 6‐exo‐dig halocyclization, and no endo products were detected. However, this cyclization reaction exhibited no apparent stereoselectivity. For each substrate, two stereoisomers, one with the (Z) and the other with the (E) configuration were isolated. In addition, under the same conditions, the 3‐butynylphosphonic monoesters did not undergo the cyclization, which indicates that the chain length between the triple bond and the phosphonyl group serves an important role in the reaction.
Iron‐Catalyzed C–H Bond Functionalization for the Exclusive Synthesis of Pyrido[1,2‐a]indoles or Triarylmethanols
Authors: Karthikeyan Iyyanar , Sekar Govindasamy 
Published: November 2014

AbstractThe efficient and selective iron‐catalyzed C–H activation of 2‐benzhydrylpyridine derivatives was employed for the preparation of pyrido[1,2‐a]indoles through an intramolecular C–H amination reaction. In the presence of molecular oxygen as the sole oxidant, the same 2‐benzhydrylpyridines were also used for the synthesis of the corresponding tertiary alcohols. In these approaches, the iron catalyst was used to selectively activate the C(sp2)–H bond of 2‐benzhydrylpyridine, in the case of the intramolecular ring‐closing C–H amination reaction in which the pyridine nitrogen atom was a directing group as well as a nucleophile, and the C(sp3)–H bond of the same compound, in the case of the oxidation reaction to give the corresponding triaryl carbinol.
Selective suppression of microglial activation by paeoniflorin attenuates morphine tolerance
Authors: Jiang C. , Xu L. , Chen L. , Han Y. , Tang J. , Yang Y. , Zhang G. , Liu W. 
Published: November 2014

AbstractBackgroundThe development of antinociceptive tolerance following repetitive administration of opioid analgesics significantly hinders their clinical use. Evidence has accumulated indicating that microglia within the spinal cord play a critical role in morphine tolerance. The present study investigated the effects and possible mechanisms of a natural compound, paeoniflorin, in morphine tolerance via its specific inhibition of microglial activation.MethodsThe microglia cell line BV‐2 was used. Cytokine expression was measured using quantitative polymerase chain reaction. Cell signalling was assayed by Western blot and immunohistochemistry. Nociception was assessed in Sprague‐Dawley rats and CD‐1 mice using Hargreaves’ methods or the hot‐plate test, respectively.Results(1) Morphine induces robust BV‐2 cell activation, as evidenced by increased p38 mitogen‐activated protein kinase (MAPK) phosphorylation, nuclear factor (NF)‐κB translocation and proinflammatory cytokine expression. These changes are inhibited by paeoniflorin. (2) Co‐administration of paeoniflorin with morphine potentiates morphine antinociception by inhibiting p38 MAPK/NF‐κB signalling in the spinal cord. (3) Co‐administration of paeoniflorin suppresses morphine‐increased expression of toll‐like receptor‐4 both in BV‐2 cells and within the spinal cord following chronic morphine treatment.ConclusionPaeoniflorin directly suppresses morphine‐induced microglial activation and thus results in potentiation of morphine acute analgesia and attenuation of morphine chronic antinociceptive tolerance.
Sensitive Phenol Detection Using Tyrosinase‐Based Phenol Oxidation Combined with Redox Cycling of Catechol
Authors: Noh Soodong , Yang Haesik 
Published: November 2014

AbstractThis paper reports sensitive phenol detection using (i) tyrosinase (Tyr)‐based oxidation of phenol to catechol, combined with (ii) electrochemical‐chemical‐chemical (ECC) redox cycling involving Ru(NH3)63+, catechol, and tris(2‐carboxyethyl)phosphine (TCEP). Phenol is converted into catechol by Tyr in the presence of dissolved O2. Catechol then reacts with Ru(NH3)63+, generating o‐benzoquinone and Ru(NH3)62+. o‐Benzoquinone is reduced back to catechol by TCEP, and Ru(NH3)62+ is accumulated over the course of the incubation. When Ru(NH3)62+ is electrochemically oxidized to Ru(NH3)63+, ECC redox cycling occurs. For simple phenol detection, bare ITO electrodes are used without modifying the electrodes with Tyr. The detection limit for phenol in tap water using Tyr‐based oxidation combined with ECC redox cycling is ca. 10−9 M, while that using only Tyr‐based oxidation is ca. 10−7 M.
Numerical assessment of a shock‐detecting sensor for low dissipative high‐order simulation of shock–vortex interactions
Authors: Khoshab Masih , Dehghan Ali Akbar , Esfahanian Vahid , Darian Hossein Mahmoodi 
Published: November 2014

SUMMARYConsidering the importance of high‐order schemes implementation for the simulation of shock‐containing turbulent flows, the present work involves the assessment of a shock‐detecting sensor for filtering of high‐order compact finite‐difference schemes for simulation of this type of flows. To accomplish this, a sensor that controls the amount of numerical dissipation is applied to a sixth‐order compact scheme as well as a fourth‐order two‐register Runge–Kutta method for numerical simulation of various cases including inviscid and viscous shock–vortex and shock–mixing‐layer interactions. Detailed study is performed to investigate the performance of the sensor, that is, the effect of control parameters employed in the sensor are investigated in the long‐time integration. In addition, the effects of nonlinear weighting factors controlling the value of the second‐order and high‐order filters in fine and coarse non‐uniform grids are investigated. The results indicate the accuracy of the nonlinear filter along with the promising performance of the shock‐detecting sensor, which would pave the way for future simulations of turbulent flows containing shocks. Copyright © 2014 John Wiley & Sons, Ltd.
Osteoinductive‐nanoscaled silk/HA composite scaffolds for bone tissue engineering application
Authors: Huang Xiaowei , Bai Shumeng , Lu Qiang , Liu Xi , Liu Shanshan , Zhu Hesun 
Published: November 2014

AbstractOsteoinductive silk/hydroxyapatite (HA) composite scaffolds for bone regeneration were prepared by combining silk with HA/silk core–shell nanoparticles. The HA/silk nanoparticles were directly dispersed in silk solution to form uniform silk/HA blend and then composite scaffolds after a freeze‐drying process. The HA/silk nanoparticles uniformly distributed in silk scaffolds at nanometer scale at varying HA content up to 40%, and substantially improved the compressive strength of the scaffolds produced. Rat bone mesenchymal stem cells (rBMSCs) were cultured in these scaffolds and cell proliferation was analyzed by confocal microscopy and DNA assay. Gene expression and biochemical assays were employed to study the influence of increasing HA/silk nanoparticles on in vitro osteogenic differentiation of rBMSCs. Increasing HA/silk nanoparticles inside silk scaffolds improved the growth and osteogenic capability of rBMSCs in the absence of osteogenic growth factors, and also significantly increased the calcium and collagen I deposition. In addition, compared to silk/HA composite scaffolds containing HA aggregates, the scaffolds loaded with HA/silk nanoparticles showed remarkably higher stiffness and better osteogenic property at same HA content, implying a preferable microenvironment for rBMSCs. These results suggest that the osteogenic property as well as mechanical property of silk/HA scaffolds could be further improved through fabricating their structure and topography at nanometer scale, providing more suitable systems for bone regeneration. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 103B: 1402–1414, 2015.
Mesenchymal Stem Cells Promote Epithelial to Mesenchymal Transition and Metastasis in Gastric Cancer Though Paracrine Cues and Close Physical Contact
Authors: Xue Zengfu , Wu Xiumin , Chen Xiong , Liu Yali , Wang Xin , Wu Kaichun , Nie Yongzhan , Fan Daiming 
Published: November 2014

ABSTRACTMesenchymal stem cells (MSCs) have been shown to integrate into the tumor stroma; however, the precise mechanisms of this process are still elusive. In this study, the EMT phenotype and the enhanced metastatic ability of tumor cells were observed using transwell and trans‐endothelial migration assays, respectively, as well as by using electron and laser confocal microscopy. Critical genes were screened and validated using gene arrays and clinical samples, and the changes at the protein level were examined both in vitro and in vivo. Cancer cells acquired an “activated” carcinoma‐associated fibroblasts (CAFs) phenotype after being in close contact with MSCs and enhancing tumor metastasis and growth in vivo. Paracrine signals also induced EMT and promoted transwell and trans‐endothelial migration, the changes were dependent on β‐catenin, MMP‐16, snail and twist. Notably, the higher expression levels of β‐catenin and MMP‐16 were correlated with tumor invasion and distant organ and lymph node metastases in intestinal type gastric cancer. MSCs within the tumor niche significantly facilitated tumor growth and metastasis by paracrine cues and close physical connection. This occurred partly through snail, twist and its downstream targets, specifically β‐catenin/MMP‐16. J. Cell. Biochem. 116: 618–627, 2015. © 2014 Wiley Periodicals, Inc.
Mutation of Spry2 Induces Proliferation and Differentiation of Osteoblasts but Inhibits Proliferation of Gingival Epithelial Cells
Authors: Sanui Terukazu , Tanaka Urara , Fukuda Takao , Toyoda Kyosuke , Taketomi Takaharu , Atomura Ryo , Yamamichi Kensuke , Nishimura Fusanori 
Published: November 2014

ABSTRACTSprouty was identified as an inhibitor of the fibroblast growth factor (FGF) receptor, and Sprouty2 (Spry2) functions as a negative regulator of receptor tyrosine kinase signaling. In this study, we investigated how inhibition of Spry2 affects osteoblasts and gingival epithelial cells in periodontal tissue regeneration in vitro. Transduction of a dominant‐negative mutant of Spry2 (Y55A‐Spry2) enhanced basic fibroblast growth factor (bFGF)‐ and epidermal growth factor (EGF)‐induced ERK activation in MC3T3‐E1 osteoblastic cells. In contrast, it decreased their activation in GE1 cells. Consistent with these observations, Y55A‐Spry2 increased osteoblast proliferation with bFGF and EGF stimulation, whereas the proliferation of Y55A‐Spry2‐introduced GE1 cells was decreased via the ubiquitination and degradation of EGF receptors (EGFRs). In addition, Y55A‐Spry2 caused upregulation of Runx2 expression and downregulation of Twist, a negative regulator of Runx2, with treatment of bFGF and EGF, resulting in enhanced osteoblastogenesis accompanied by alkaline phosphatase activation and osteocalcin expression in MC3T3‐E1 cells. These data suggest that suppression of Spry2 expression induces proliferation and differentiation of osteoblastic cells after the addition of a bFGF and EGF cocktail but inhibits proliferation in gingival epithelial cells. These in vitro experiments may provide a molecular basis for novel therapeutic approaches in periodontal tissue regeneration. Taken together, our study proposes that combined application of an inhibitor for tyrosine 55 of Spry2, bFGF, and EGF may effectively allow alveolar bone growth and block the ingrowth of gingival epithelial cells toward bony defects, biologically mimicking a barrier effect in guided tissue regeneration, with in vivo investigation in the future. J. Cell. Biochem. 116: 628–639, 2015. © 2014 Wiley Periodicals, Inc.
lncRNA Expression Signatures in Periodontitis Revealed by Microarray: The Potential Role of lncRNAs in Periodontitis Pathogenesis
Authors: Zou Yaguang , Li Chun , Shu Fangpeng , Tian Zhihui , Xu Wenan , Xu Huiyong , Tian Hua , Shi Rong , Mao Xiangming 
Published: November 2014

ABSTRACTPeriodontitis, a common chronic inflammatory disease of the periodontium, is caused by dental plaque formation induced by microorganisms. Recent studies have demonstrated that lncRNAs play a critical role in the regulation of gene expression and in the pathogenesis of diseases. To demonstrate that periodontitis is associated with lncRNAs, microarray analysis was used to detect differently expressed lncRNAs in chronic periodontitis and adjacent normal tissues. The results of some differently expressed lncRNAs were further confirmed using real‐time PCR. A total of 8925 differentially expressed lncRNAs were detected, including 4313 upregulated lncRNAs and 4612 downregulated lncRNAs. Further lncRNA subgroup analysis showed there were 589 enhancer‐like lncRNAs, 238 homeobox (HOX) cluster lncRNAs, and 1218 Rinn's lincRNAs, of which 656 lincRNAs were upregulated and 562 lincRNAs were downregulated. Therefore, we confirmed that lncRNAs were differently expressed in chronic periodontitis tissues compared with adjacent normal tissues, indicating that lncRNAs may exert partial or key roles in periodontitis pathogenesis and development. Taken together, this study may provide potential targets for future treatment of periodontitis and novel diagnostic biomarkers for periodontitis. J. Cell. Biochem. 116: 640–647, 2015. © 2014 Wiley Periodicals, Inc.
Safety considerations of mammalian target of rapamycin inhibitors in tuberous sclerosis complex and renal transplantation
Authors: Somers Michael J.G. , Paul Elahna 
Published: November 2014

AbstractRapamycin‐related mTOR inhibitors (rapalogs) possess immunosuppressive and antiproliferative properties. Their mechanism of action makes them attractive therapies for several disease states but also potentiates adverse effects associated with these drugs. The oral mTOR inhibitor everolimus was recently approved for the treatment of tuberous sclerosis complex (TSC)‐associated renal angiomyolipoma. As clinical use of rapalogs for the treatment of TSC increases, nephrologists and urologists who treat both children and adults with renal masses, as well as internists and geneticists with an interest in renal disease, should be aware of their safety profiles. This review presents the clinical experience of rapamycin‐related mTOR inhibitors in patients with TSC and summarizes their toxicity profiles in renal transplant and TSC populations. Increased usage of rapalogs in a variety of patient populations demands vigilant monitoring of their safety profiles and rigorous differentiation between disease‐specific and drug‐specific toxicities.
To retire or not to retire: That is not the question
Authors: Beehr Terry A. 
Published: November 2014

SummaryRetirement decisions are multiple choice, not true–false, because retirement takes many forms. Multiple theories have been used to predict retirement and to do research on it, but rational‐economic decision‐making theories, often assuming intentional behavior, dominate the retirement research domain. Although employment serves both manifest (economic) and latent (psychological) functions, research on the decision to move from employment to retirement has focused on the manifest function. Economics tend to play a strong role in employees' retirement decisions, with health probably a close second predictor. Three phases of retirement decision‐making are evident: (i) imagining the possibility of one's future life during retirement; (ii) assessing the past to help decide when to retire; and (iii) the transition to retirement. Both predictors and consequences of retirement are reviewed, with special attention given to bridge employment, the phenomenon of retirees working for pay. Copyright © 2014 John Wiley & Sons, Ltd.
The Role of Childhood Trauma and PTSD in Postpartum Sleep Disturbance
Authors: Swanson Leslie M. , Hamilton Lindsay , Muzik Maria 
Published: November 2014

Despite robust associations between postpartum sleep difficulties and maternal psychopathology, little attention has been paid to the role of childhood trauma and posttraumatic stress disorder (PTSD). In the present study, we examined sleep complaints in postpartum women with a history of childhood trauma compared to postpartum women who were not exposed to childhood trauma. Participants (N = 173) completed questionnaires by telephone at 4‐months postpartum. After adjusting for nuisance variables, there were significantly higher rates of sleep disturbance (falling asleep and staying asleep) for women with a past history of neglect (OR = 4.84, p = .036 and 5.78, p = .006, respectively), physical abuse (OR = 9.20, p = .002 and 3.84, p = .044, respectively), and physical abuse with sexual abuse (OR = 5.95, p = .011 and 3.56, p = .045, respectively). Current PTSD was significantly associated with trouble staying asleep (OR = 4.21, p = .032) whereas recovery from PTSD was associated with trouble falling (OR = 4.19, p = .015) and staying asleep (OR = 3.69, p = .011). Our findings affirm the contribution of childhood trauma and PTSD to postpartum sleep.
Photocontrol of Mechanical Properties of Pulp Fibers and Fiber‐to‐Fiber Bonds via Self‐Assembled Polysaccharide Derivatives
Authors: Grigoray Olga , Wondraczek Holger , Daus Stephan , Kühnöl Katrin , Latifi Seyed Kourosh , Saketi Pooya , Fardim Pedro , Kallio Pasi , Heinze Thomas 
Published: November 2014

AbstractPhotoresponsive pulp fibers are prepared by self‐assembly of photoactive cationic cellulose derivatives with pulp fibers in aqueous environment. Photoactive groups of the derivatives undergo 2π + 2π cycloaddition reaction under UV‐light irradiation. Fast photocrosslinking leads to the formation of the covalent bonds between the photoactive groups on the fiber surfaces. This results in drastic enhancement of the mechanical properties of the fiber network. Tensile strength and Z‐directional tensile strength increase by 81 and 84% compared to the original fiber network. Stiffness of the individual fibers increases by 60%. Such concept of controlling mechanical properties of the fiber materials by the light gives a possibility to design smart bio‐based materials and to increase end value of the fiber products.
Solar photovoltaic energy policy and globalization: a multiperspective approach with case studies of Germany, Japan, and China
Authors: Yu Hyun Jin Julie , Popiolek Nathalie , Geoffron Patrice 
Published: November 2014

AbstractSolar photovoltaic (PV) systems have experienced strong market growth over the last decade. Since the mid‐2000s, the increase in demand in line with policy supports in Europe has attracted the Chinese players into the PV manufacturing market. Chinese production soared in a short time and managed to quickly reduce the cost thanks to large‐scale supply with mass‐produced products. Faced with the global economic crisis, the European countries began reducing their policy supports that caused a decrease in the demand for PV installations. Despite such a market situation, Chinese PV manufacturers have continued to produce large quantities of solar PV products and thereby aggravated the global PV industry situation with a global supply–demand imbalance. China's rapid market expansion without domestic market development has brought unexpected results with an oversupply of PV materials and equipment in a global market and destabilized the PV market. It influenced the PV policy mechanisms of other countries. Many PV firms in the world have since gone into bankruptcy. China and Europe lately went through a trade dispute over the Chinese solar panel imports (dumping suspicion). In this context, this study aims to identify the PV policy mechanisms based on a multiperspective approach in Germany, Japan, and China. A systematic logical framework is proposed and then used to explain each country's PV policy strategy and results. Moreover, PV globalization impacts and interactions among them are studied using the international trade theory. At the end, this research also attempts to seek optimal strategies to improve the global PV mechanisms. Copyright © 2014 John Wiley & Sons, Ltd.
Isobutylene‐rich macromonomers: Dynamics and yields of peroxide‐initiated crosslinking
Authors: Dakin Jackson M. , Shanmugam Karthik Vikram Siva , Twigg Christopher , Whitney Ralph A. , Parent J. Scott 
Published: November 2014

ABSTRACTNew isobutylene‐rich elastomers bearing multiple pendant styrenic, acrylic, maleimidic, vinylic, and allylic functional groups have been prepared and examined in the context of peroxide‐initiated crosslinking. Halide displacement from brominated poly(isobutylene‐co‐isoprene) (BIIR) by the requisite carboxylate nucleophiles in homogeneous toluene solutions provide the desired esters in quantitative yield without complications from dehydrohalogenation or premature crosslinking. Heating the resulting macromonomers with dicumyl peroxide to 160 °C under solvent‐free conditions gives thermoset derivatives, with reaction rates and yields depending markedly on functional group structure. In general, high cure extents can only be achieved using highly reactive pendant functional groups, owing to the competitive balance between crosslinking through CC oligomerization, and degradation through β‐scission of backbone macroradical intermediates. Independent control of crosslinking rates and cure extents is gained through the use of nitroxyl radical traps bearing acrylate functionality. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 123–132
Asymmetric mutations in the tetrameric R67 dihydrofolate reductase reveal high tolerance to active‐site substitutions
Authors: Ebert Maximilian C. C. J. C. , Morley Krista L. , Volpato Jordan P. , Schmitzer Andreea R. , Pelletier Joelle N. 
Published: November 2014

AbstractType II R67 dihydrofolate reductase (DHFR) is a bacterial plasmid‐encoded enzyme that is intrinsically resistant to the widely‐administered antibiotic trimethoprim. R67 DHFR is genetically and structurally unrelated to E. coli chromosomal DHFR and has an unusual architecture, in that four identical protomers form a single symmetrical active site tunnel that allows only one substrate binding/catalytic event at any given time. As a result, substitution of an active‐site residue has as many as four distinct consequences on catalysis, constituting an atypical model of enzyme evolution. Although we previously demonstrated that no single residue of the native active site is indispensable for function, library selection here revealed a strong bias toward maintenance of two native protomers per mutated tetramer. A variety of such “half‐native” tetramers were shown to procure native‐like catalytic activity, with similar KM values but kcat values 5‐ to 33‐fold lower, illustrating a high tolerance for active‐site substitutions. The selected variants showed a reduced thermal stability (Tm ∼12°C lower), which appears to result from looser association of the protomers, but generally showed a marked increase in resilience to heat denaturation, recovering activity to a significantly greater extent than the variant with no active‐site substitutions. Our results suggest that the presence of two native protomers in the R67 DHFR tetramer is sufficient to provide native‐like catalytic rate and thus ensure cellular proliferation.