bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression and phosphorylation of eukaryotic translation initiation factor 4‐gamma (eIF4G) in denervated atrophic and hypertrophic mouse skeletal muscle
Authors: Fjällström Ann‐Kristin , Norrby Marlene , Tågerud Sven 
Published: December 2014

AbstractThe eukaryotic translation initiation factor 4‐gamma (eIF4G) is important for the initiation of protein synthesis and phosphorylation on S1108 regulates this function of eIF4G. Thus, increased phosphorylation has been reported in conditions associated with increased protein synthesis such as meal feeding and insulin/IGF‐1 treatment whereas decreased phosphorylation occurs following starvation, dexamethasone treatment, in sepsis and in atrophic denervated hind‐limb muscle. The aim of the present study was to test the hypothesis that S1108 phosphorylation of eIF4G is differentially affected in denervated atrophic hind‐limb muscles and denervated hypertrophic hemidiaphragm muscle. Protein expression and phosphorylation in innervated and 6‐days denervated atrophic hind‐limb muscles (pooled gastrocnemius and soleus) and hypertrophic hemidiaphragms were studied semi‐quantitatively using Western blots. Total expression of eIF4G did not change in denervated hind‐limb muscles but increased about 77% in denervated hemidiaphragm. S1108 phosphorylated eIF4G decreased about 64% in denervated hind‐limb muscles but increased about 1.3‐fold in denervated hemidiaphragm. The ratio of S1108 phosphorylated eIF4G to total eIF4G decreased about 60% in denervated hind‐limb muscles but no statistically significant change was observed in denervated hemidiaphragm. The differential effect of denervation on eIF4G expression and S1108 phosphorylation in hemidiaphragm (hypertrophic) and hind‐limb muscle (atrophic) may represent a regulatory mechanism that helps clarify the differential response of these muscles following denervation.
Inhibition of iron uptake by ferristatin II is exerted through internalization of DMT1 at the plasma membrane
Authors: Yanatori Izumi , Yasui Yumiko , Noguchi Yumiko , Kishi Fumio 
Published: December 2014

AbstractFerristatin II, discovered as an iron transport inhibitor, promotes the internalization and degradation of transferrin receptor 1 (TfR1). DMT1, which mediates iron transport across cell membranes, is located at the plasma membrane of enterocytes and imports dietary iron into the cytosol. TfR1 is not directly engaged in the intestinal absorption of free iron, and iron uptake by DMT1 is attenuated by ferristatin II treatment. In this study, we found another function for ferristatin II in iron uptake. Ferristatin II did not cause degradation of DMT1 but did induce DMT1 internalization from the plasma membrane. Dynasore, a small molecule inhibitor of dynamin, did not inhibit this internalization by ferristatin II, which might occur via a clathrin‐independent pathway.
The role of eNOS in the migration and proliferation of bone‐marrow derived endothelial progenitor cells and in vitro angiogenesis
Authors: Lu Aizhen , Wang Libo , Qian Liling 
Published: December 2014

AbstractThe role of endothelial nitric oxide synthase (eNOS) in the activities of endothelial progenitor cells (EPCs) including migration, proliferation, and tube formation in vitro was investigated. EPCs were obtained from rat bone mononuclear cells by culturing for 7–10 days in EGM‐2MV and identified by their capacity for FITC‐UEA‐1 binding and acetylated low‐density lipoprotein (Dil‐ac‐LDL) intake using fluorescence microscopy. Migration, proliferation and tube formation activities were assessed in the presence or absence of Nω‐nitro‐L‐argininemethylester (L‐NAME), an eNOS inhibitor. mRNA and protein expression of CXCR4, CXCR7, VEGFR2, and eNOS were detected by real‐time PCR and western blotting in the presence or absence of L‐NAME. Nitric oxide production was detected by nitrate reductase in the presence or absence of L‐NAME. Typical spindle‐shaped cells appeared on the 7th–10th day and confluence reached about 80%. The percentage of FITC‐UEA‐1 and Dil‐ac‐LDL double‐stained cells was about 85%. Cell migration, proliferation, and tube formation were significantly weakened after eNOS was inhibited (P < 0.05), and the expressions of CXCR4 and eNOS were significantly reduced (P < 0.05, respectively), but there was little change in CXCR7 and VEGFR2. NO production was dramatically decreased after eNOS was inhibited (P < 0.05). In summary, L‐NAME significantly reduced the expression of eNOS and NO production by EPCs and inhibited migration, proliferation and tube formation by these cells, suggesting that eNOS affects EPC activities; CXCR4 may be implicated in the action of eNOS.
IL‐21 induction of CD4+ T cell differentiation into Th17 cells contributes to bleomycin‐induced fibrosis in mice
Authors: Lei Ling , Zhong Xiao‐Ning , He Zhi‐Yi , Zhao Cheng , Sun Xue‐Jiao 
Published: December 2014

AbstractSystemic sclerosis (SSc) is a connective tissue disease characterized by fibrosis of the skin and internal organs. Th17 cells and interleukin‐17 (also called IL‐17A) have been found to be increased in peripheral blood and skin in patients with SSc. IL‐21 is a potent inducer of Th17 differentiation that is produced by activated T cells, and whose relationship with Th17 cells in SSc is unclear. Here, using a bleomycin (BLM)‐induced mouse model of skin fibrosis, we detected the frequency of CD4+/IL‐17+ (Th17) cells, CD4+/IL‐21+ T cells and IL‐21+ Th17 cells in peripheral blood, skin and lungs, as well as the serum content of IL‐17A and IL‐21. In addition, we assessed the differentiation of CD4+ T cells cultured from these mice into Th17 cells in response to treatment with IL‐21. Compared with the control mice, Th17 cell counts and IL‐17A levels were significantly increased and correlated with inflammatory and fibrotic indices in the skin and lungs of the BLM‐induced fibrosis mice. Moreover, serum levels of CD4+/IL‐21+ T cells, IL‐21+ Th17 cells, and IL‐21 were significantly increased in these mice, and correlated positively with serum levels of Th17 cells. In vitro experiments showed that IL‐21 treated CD4+ T cells derived from BLM‐induced mice differentiated into Th17 cells. Our results indicate that Th17 cells and IL‐17A contributes to inflammatory and fibrotic processes in the skin and lungs in a BLM‐induced mouse model of SSc. Moreover, the expansion of the Th17 cell population may be subsequent to IL‐21 promotion of the differentiation of CD4+ T cells in these mice.
Reprogramming of endometrial adult stromal cells in the presence of a ROCK inhibitor, thiazovivin, could obtain more efficient iPSCs
Authors: Mohseni Rashin , Shoae‐Hassani Alireza , Verdi Javad 
Published: December 2014

AbstractToday, there is a need for a platform to efficiently generate and maintain a feeder free culture of pluripotent stem cells by small molecules or pharmacological agents. Induced pluripotent stem cell (iPSC) is considered a promising resource for restorative cell therapy in clinical areas. While fully reprogrammed iPSCs are similar to embryonic stem cells, iPSCs could be derived from the patient's own cells (autologous), which avoids the immune rejection activities. Recent advances have demonstrated that iPSCs could be generated from human fibroblasts using only four transcription factors: OCT4, SOX2, CMYC, and KLF4. However, the limitations of reprogramming technologies include low efficiency, slow kinetics, transgene integration and residual expression. Surprisingly, adult stem cells from human endometrium (endometrial stem cells; EnSCs) express OCT4 and KLF4 pluripotency factors. On the other hand, small molecule inhibitors of specific signaling pathways such as thiazovivin have been used in various aspects of iPSC generation and maintenance. Thiazovivin is a selective small molecule that directly targets Rho‐associated kinase (ROCK) and increases expression of pluripotency factors. The process using thiazovivin could be easier, faster and more cost effective than transgene integration into somatic cells. So reprogramming of OCT4 and KLF4 expressing EnSCs by a ROCK inhibitor, thiazovivin, could result in producing more efficient iPSCs compared with fibroblasts or conventional somatic cells without integration any transgene and retroviral vector.
Nickel‐Supported on La2Sn2O7 and La2Zr2O7 Pyrochlores for Methane Steam Reforming: Insight into the Difference between Tin and Zirconium in the B Site of the Compound
Authors: Ma Youhe , Wang Xiang , You Xiaojuan , Liu Jianjun , Tian Jinshu , Xu Xianglan , Peng Honggen , Liu Wenming , Li Changqing , Zhou Wufeng , Yuan Ping , Chen Xiaohong 
Published: December 2014

AbstractLa2Sn2O7 and La2Zr2O7, two pyrochlore compounds with different B‐site cations, were prepared and used as supports for Ni in methane steam reforming. Compared with Ni/γ‐Al2O3, both Ni/La2Zr2O7 and Ni/La2Sn2O7 show very stable reaction performance. Whereas Ni/La2Zr2O7 also displays reasonably high activity for the reaction, the activity of Ni/La2Sn2O7 is extremely low. It was found that severe coking occurred with Ni/γ‐Al2O3, but no coke formation was observed on the two pyrochlore catalysts. On the reduced and spent Ni/La2Sn2O7 catalyst, the Ni3Sn2 and Ni3Sn alloys were detected; these alloys suppressed coke formation but also decreased the activity of the catalyst. In comparison, a large amount of La2O2CO3 was formed on the used Ni/La2Zr2O7 catalyst; these species reacted with the carbon deposits formed on the Ni particles and continuously restored the Ni sites. Thus, coking was effectively suppressed and the initial high activity of the catalyst was maintained. Thus, Ni/La2Zr2O7 is a superior catalyst having the potential for industrial use.
Formation of Intermetallic Compounds by Reactive Metal–Support Interaction: A Frequently Encountered Phenomenon in Catalysis
Authors: Penner Simon , Armbrüster Marc 
Published: December 2014

AbstractThis Review discusses the structural and catalytic aspects of the recently introduced reactive metal–support interaction. This special term was coined to account for the inability of the original concept of the strong metal–support interaction to accurately describe the structural, compositional, and electronic changes frequently occurring in oxide‐supported metal particle catalysts at very high temperatures upon reduction in hydrogen, in many cases leading to intermetallic compound or substitutional alloy formation. This inaccuracy predominantly refers to the requirement of full reversibility upon oxidation and mild reduction for a “strong” metal–support interaction. A close look at the formation of oxide‐supported intermetallic compounds upon high‐temperature reduction reveals that these compounds are very common in catalysis and the situation is much more complex compared to unsupported intermetallic compounds due to the presence of the intermetallic compound–oxide interface.
Metal Nanoparticles Immobilized on Carbon Nanodots as Highly Active Catalysts for Hydrogen Generation from Hydrazine in Aqueous Solution
Authors: Sun Jian‐Ke , Xu Qiang 
Published: December 2014

AbstractWell‐dispersed PtNi nanoparticles (NPs) grown on carbon nanodots (CNDs) derived from a metal–organic framework (ZIF‐8) are synthesized by a simple reduction of metal precursors in the presence of CNDs, wherein the CNDs prove to be a powerful dispersion agent and distinct support for the PtNi NPs. The resultant PtNi‐CND catalyst exerts almost 100 % H2 selectivity and a high activity for the decomposition of hydrous hydrazine at room temperature. This excellent catalytic performance might be a result of the synergistic effect of the CND support and the PtNi NPs. The utilization of CNDs as a support to anchor the active component NPs and thus to facilitate the electron transfer and mass transport kinetics during the catalytic reaction process opens up new avenues to design high‐performance catalysts.
Exploration of the Substrate Promiscuity of Biosynthetic Tailoring Enzymes as a New Source of Structural Diversity for Polyene Macrolide Antifungals
Authors: Santos‐Aberturas Javier , Engel Jennifer , Dickerhoff Jonathan , Dörr Mark , Rudroff Florian , Weisz Klaus , Bornscheuer Uwe T. 
Published: December 2014

AbstractEven though there is an urgent need for new antifungals with improved clinical properties, the substrate promiscuity of tailoring enzymes has been poorly studied as a source of new structural diversity for polyene macrolides. We explore the acceptance of different polyene macrolides by the glutamine amidotransferase PscA and the catalytic effect of different homologous P450 cytochromes on a common scaffold, the pimaricin precursor 4,5‐desepoxypimaricin. By combining these two parallel strategies, we present three new pimaricin derivatives and a new lucensomycin variant. Our results show that P450 cytochromes devoted to the modification of the polyol region of polyene macrolides are not as substrate‐specific as previously thought and highlight PscA as a versatile small‐ring polyene‐modifying enzyme that allows the preparation of new carboxamide derivatives. We also provide useful information for the future production of previously unconceived epoxidized polyene macrolide antifungals.
Transfer Hydrogenation of Ketones, Nitriles, and Esters Catalyzed by a Half‐Sandwich Complex of Ruthenium
Authors: Lee Sun‐Hwa , Nikonov Georgii I. 
Published: December 2014

AbstractHalf‐sandwich complexes [Cp(PiPr3)Ru(CH3CN)2]PF6 (1; Cp=cyclopentadienyl) and [Cp*(phen)Ru(CH3CN)]PF6 (2; Cp*=pentamethylcyclopentadienyl, phen=phenanthroline) catalyse the transfer hydrogenation of ketones to alcohols, aldimines to amines, and nitriles to imines under mild conditions. In the latter process, the imine products come from the coupling of the amines formed initially with acetone derived from the reducing solvent (isopropanol). Among functionally substituted nitriles, the aldo and keto groups are reduced concomitantly with the cyano group, whereas ester and amido groups are tolerated. Amides and alkyl esters are not reduced under these conditions even upon heating to 70 °C. However, phenylbenzoates and trifluoroacetates are reduced to alcohols. Kinetic studies on the reduction of acetophenone in isopropanol established that the reaction is first order in both the substrate and the alcohol. Stoichiometric mechanistic studies showed the formation of a hydride species. A hydride mechanism was proposed to account for these observations.
Continuous Flow Preparation of Iron Oxide Nanoparticles Supported on Porous Silicates
Authors: Yepez Alfonso , Lam Frank L. Y. , Romero Antonio A. , Kappe C. Oliver , Luque Rafael 
Published: December 2014

AbstractA simple, innovative, and efficient continuous flow methodology for the direct preparation of supported nanoparticles on porous materials by using metal precursor solution flowing through heated packed‐bed reactors containing the support material has been developed. The effects of the flow rate of the precursor solution, temperature, and nature of the support material and metal loading have been investigated. Results indicated that optimum conditions comprised short residence times (with typical flow rates of 0.5 mL min−1 and below) under mild heating (100 °C) to achieve optimum materials in terms of nanoparticle size and structure and catalytic activity. The support was found to have a remarkable effect on both loading and distribution and agglomeration of nanoparticles in the system, with a previously reported Fe/Al synergy also observed in the prepared nanomaterials, which led to optimum results.
Effects of Viscous Dissipation and Rarefaction on Parallel Plates with Constant Heat Flux Boundary Conditions
Authors: Kushwaha Hari Mohan , Sahu Santosh K. 
Published: December 2014

AbstractThe effect of viscous dissipation and rarefaction on heat transfer characteristics of hydrodynamically and thermally fully developed flow between parallel plates with constant heat flux conditions is analyzed. Three different types of heat flux boundary conditions, i.e., both plates kept at different constant heat fluxes, both plates kept at equal constant heat fluxes, and one plate insulated, are applied. In all cases, closed form expressions are obtained for the temperature distribution and Nusselt number. Viscous dissipation, rarefaction, and heat flux ratio are found to influence the heat transfer substantially. The present predictions are verified for the cases which neglect the microscale and viscous heating effect. The obtained results are in good agreement with other analytical results.
Esterification of Renewable Levulinic Acid to n‐Butyl Levulinate over Modified H‐ZSM‐5
Authors: Nandiwale Kakasaheb Y. , Bokade Vijay V. 
Published: December 2014

AbstractThe synthesis of n‐butyl levulinate, one of the most important biodiesel additives, by catalytic esterification of biomass‐derived levulinic acid (LA) with n‐butanol over modified H‐ZSM‐5 (micro/meso‐HZ‐5) in a closed‐batch system is reported for the first time. The optimization of the reaction conditions such as the reactant molar ratio, the catalyst loading, the reaction time and the temperature was performed in view to maximize the yield of n‐butyl levulinate. Micro/meso‐HZ‐5 was found to be the most efficient catalyst, with 98 % yield of n‐butyl levulinate and a reusability for six cycles, which is higher than reported in the literature. A possible catalytic mechanism for the esterification reaction is also proposed. A second‐order pseudo‐homogeneous model with R2 > 0.97 confirmed that the esterification reaction is performed in the kinetic regime due to the high activation energy of 23.84 kJ mol−1.
Design and Control of Ionic Liquid‐Catalyzed Reactive Distillation for n‐Butyl Acetate Production
Authors: Peng Xuan , Wang Likun 
Published: December 2014

AbstractA simulation study of n‐butyl acetate production with the [Hpy][HSO4] ionic liquid catalyst was performed. Due to the lack of phase equilibrium data, the binary interaction parameters of the NRTL model for ionic liquid and reactive species were calculated by the COSMO‐RS technique. A reactive distillation process with recycled ionic liquid stream was proposed, and the column configuration was optimized by minimization of the total annual capital. The novel process is considerably efficient and economic compared to the traditional reactive distillation process of nonionic liquids. With the steady‐state parameters, a plant‐wide control structure was further developed to evaluate the robustness of the control system by exerting the disturbances of feed flow rate and feed composition. Dynamic simulation results suggest that the control scheme with a composition controller is timely and effective.
Manipulating the Hydrocarbon Selectivity of Copper Nanoparticles in CO2 Electroreduction by Process Conditions
Authors: Kas Recep , Kortlever Ruud , Yılmaz Hasan , Koper Marc T. M. , Mul Guido 
Published: December 2014

AbstractThe formation of ethylene in CO2 electroreduction over rough copper electrodes is often explained by the presence of specific surface crystal steps, edges and defects. We demonstrate that an identical electrode covered with copper nanoparticles can yield either predominantly ethylene or methane, depending on the electrolyte concentration and applied CO2 pressure. Calculations of the pH near the electrode surface suggest that ethylene formation is favored by a relatively high (local) pH. Furthermore, the conditions leading to the formation of significant amounts of methane result in rapid deterioration of hydrocarbon production rates, whereas electrode performance in conditions favoring ethylene production can be sustained for hours. This study substantially alters the mechanistic interpretation of formation of ethylene over rough copper surfaces and implies that applied process conditions inducing pH variations near the electrode surface need to be taken into consideration.
Insights into Functional‐Group‐Tolerant Polymerization Catalysis with Phosphine–Sulfonamide Palladium(II) Complexes
Authors: Jian Zhongbao , Falivene Laura , Wucher Philipp , Roesle Philipp , Caporaso Lucia , Cavallo Luigi , Göttker‐Schnetmann Inigo , Mecking Stefan 
Published: December 2014

AbstractTwo series of cationic palladium(II) methyl complexes {[(2‐MeOC6H4)2PC6H4SO2NHC6H3(2,6‐R1,R2)]PdMe}2[A]2 (X1+‐A: R1=R2=H: H1+‐A; R1=R2=CH(CH3)2: DIPP1+‐A; R1=H, R2=CF3: CF31+‐A; A=BF4 or SbF6) and neutral palladium(II) methyl complexes {[(2‐MeOC6H4)2PC6H4SO2NC6H3(2,6‐R1,R2)]PdMe(L)} (X1‐acetone: L=acetone; X1‐dmso: L=dimethyl sulfoxide; X1‐pyr: L=pyridine) chelated by a phosphine–sulfonamide were synthesized and fully characterized. Stoichiometric insertion of methyl acrylate (MA) into all complexes revealed that a 2,1 regiochemistry dominates in the first insertion of MA. Subsequently, for the cationic complexes X1+‐A, β‐H elimination from the 2,1‐insertion product X2+‐AMA‐2,1 is overwhelmingly favored over a second MA insertion to yield two major products X4+‐AMA‐1,2 and X5+‐AMA. By contrast, for the weakly coordinated neutral complexes X1‐acetone and X1‐dmso, a second MA insertion of the 2,1‐insertion product X2MA‐2,1 is faster than β‐H elimination and gives X3MA as major products. For the strongly coordinated neutral complexes X1‐pyr, no second MA insertion and no β‐H elimination (except for DIPP2‐pyrMA‐2,1) were observed for the 2,1‐insertion product X2‐pyrMA‐2,1. The cationic complexes X1+‐A exhibited high catalytic activities for ethylene dimerization, affording butenes (C4) with a high selectivity of up to 97.7 % (1‐butene: 99.3 %). Differences in activities and selectivities suggest that the phosphine–sulfonamide ligands remain coordinated to the metal center in a bidentate fashion in the catalytically active species. By comparison, the neutral complexes X1‐acetone, X1‐dmso, and X1‐pyr showed very low activity towards ethylene to give traces of oligomers. DFT analyses taking into account the two possible coordination modes (O or N) of the sulfonamide ligand for the cationic system CF31+ suggested that the experimentally observed high activity in ethylene dimerization is the result of a facile first ethylene insertion into the O‐coordinated PdMe isomer and a subsequent favored β‐H elimination from the N‐coordinated isomer formed by isomerization of the insertion product. Steric hindrance by the N‐aryl substituent in the neutral systems CF31 and H1 appears to contribute significantly to a higher barrier of insertion, which accounts for the experimentally observed low activity towards ethylene oligomerization.
Dinuclear Rare‐Earth Metal Alkyl Complexes Supported by Indolyl Ligands in μ‐η2:η1:η1 Hapticities and their High Catalytic Activity for Isoprene 1,4‐cis‐Polymerization
Authors: Zhang Guangchao , Wei Yun , Guo Liping , Zhu Xiancui , Wang Shaowu , Zhou Shuangliu , Mu Xiaolong 
Published: December 2014

AbstractTwo series of new dinuclear rare‐earth metal alkyl complexes supported by indolyl ligands in novel μ‐η2:η1:η1 hapticities are synthesized and characterized. Treatment of [RE(CH2SiMe3)3(thf)2] with 1 equivalent of 3‐(tBuNCH)C8H5NH (L1) in THF gives the dinuclear rare‐earth metal alkyl complexes trans‐[(μ‐η2:η1:η1‐3‐{tBuNCH(CH2SiMe3)}Ind)RE(thf)(CH2SiMe3)]2 (Ind=indolyl, RE=Y, Dy, or Yb) in good yields. In the process, the indole unit of L1 is deprotonated by the metal alkyl species and the imino CN group is transferred to the amido group by alkyl CH2SiMe3 insertion, affording a new dianionic ligand that bridges two metal alkyl units in μ‐η2:η1:η1 bonding modes, forming the dinuclear rare‐earth metal alkyl complexes. When L1 is reduced to 3‐(tBuNHCH2)C8H5NH (L2), the reaction of [Yb(CH2SiMe3)3(thf)2] with 1 equivalent of L2 in THF, interestingly, generated the trans‐[(μ‐η2:η1:η1‐3‐{tBuNCH2}Ind)Yb(thf)(CH2SiMe3)]2 (major) and cis‐[(μ‐η2:η1:η1‐3‐{tBuNCH2}Ind)Yb(thf)(CH2SiMe3)]2 (minor) complexes. The catalytic activities of these dinuclear rare‐earth metal alkyl complexes for isoprene polymerization were investigated; the yttrium and dysprosium complexes exhibited high catalytic activities and high regio‐ and stereoselectivities for isoprene 1,4‐cis‐polymerization.