bluuebunny/crossref_metadata_2025_split huggingface dataset:
X‐shooting Herbig Ae/Be stars: Accretion probed by near‐infrared He I emission
Authors: Oudmaijer R.D. , van den Ancker M.E. , Baines D. , Caselli P. , Drew J.E. , Hoare M.G. , Lumsden S.L. , Montesinos B. , Sim S. , Vink J.S. , Wheelwright H.E. , de Wit W.J. 
Published: March 2011

AbstractThe Herbig Ae/Be stars are intermediate mass pre‐main sequence stars that bridge the gap between the low mass T Tauri stars and the Massive Young Stellar Objects. In this mass range, the acting star forming mechanism switches from magnetically controlled accretion to an as yet unknown mechanism, but which is likely to be direct disk accretion onto the star. We observed a large sample of Herbig Ae/Be stars with X‐shooter to address this issue from a multi‐wavelength perspective. It is the largest such study to date, not only because of the number of objects involved, but also because of the large wavelength coverage from the blue to the near‐infrared. This allows many accretion diagnostics to be studied simultaneously. By correlating the various properties with mass, temperature and age, we aim to determine where and whether the magnetically controlled mass accretion mechanism halts and the proposed direct disk accretion takes over. Here, we will give an overview of the background, present some observations and discuss our initial results. We will introduce a new accretion diagnostic for the research of Herbig Ae/Be stars, the HeI 1.083 μm line (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐shooter GTO observations and chemical tagging of two main‐sequence stars in the globular cluster NGC 2808
Authors: Bragaglia A. , Carretta E. , Gratton R.G. , Lucatello S. , Milone A. , Piotto G. , D'Orazi V. , Cassisi S. , Sneden C. , Bedin R.L. 
Published: March 2011

AbstractWe observed two main sequence stars in the globular cluster NGC 2808, using X‐shooter. We selected one of the targets on the blue main sequence (bMS) and one on the red main sequence (rMS) and measured abundances for several light elements that are expected to be different in stars of first and second generations in globular clusters. The differences between the bMS and the rMS stars amply exceed the errors and is in agreement with a difference in products of hydrogen burning at high temperature. More data are required to put the findings on more solid basis and to try to distinguish between the different models proposed to explain the formation of globular clusters (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Interacting binaries: Science cases where simultaneous multicolor medium‐resolution spectroscopy makes a difference
Authors: Mason E. , Gandhi P. 
Published: March 2011

AbstractThis contribution to “The 1st year of science with X‐shooter” conference illustrates 2 different applications of the new ESO multi‐waveband spectrograph to the study of interacting binaries. In particular we present spectra collected during the late decline of U Sco 2010 outburst and during a low/hard X‐ray phase of the black hole candidate GX339‐4. In both cases the unprecedented spectral coverage and resolution offered by X‐shooter have unveiled unexpected features (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
GRB‐selected galaxies
Authors: Jakobsson P. , Malesani D. , Hjorth J. , Fynbo J.P.U. , Milvang‐Jensen B. 
Published: March 2011

AbstractWe describe the current status and recent results from our Swift/VLT legacy survey, a VLT Large Programme aimed at characterizing the host galaxies of a homogeneously selected sub‐sample of Swift gamma‐ray bursts (GRBs). The immediate goals are to determine the host luminosity function, study the effects of reddening, determine the fraction of Lyα emitters in the hosts, and obtain redshifts for targets without a reported one. We have defined a very carefully selected sample, obeying strict and well‐defined criteria: 68 targets in total. Among the preliminary results is a large optical detection rate, the lack of extremely red objects (only one possible case in the sample), and 10 new GRB redshifts with the mean redshift of the host sample assessed to be 〈z 〉 ≳ 2 (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The high redshift intergalactic and interstellar media with X‐shooter
Authors: Petitjean P. 
Published: March 2011

AbstractI review here a few important questions that X‐shooter can help tackle and answer in the field of quasar absorption lines. This includes (i) determine the ionizing background and the physical state of the inter‐galactic medium (IGM) by analysing the characteristics of the Lyman‐α forest and the proximity effect; (ii) investigate the metal content of the high redshift IGM; (iii) study the small scale transverse correlation in the IGM by observing pairs of quasars with small separation in the sky; (iv) study the galaxy‐IGM relations by detecting the counterpart of damped Lyman‐α systems (DLAs) or determining the correlation between the properties of galaxies and absorption lines; (v) detect and characterize the long‐sought cold diffuse molecular (H2 and CO) interstellar medium (ISM) of high redshift galaxies and study its dust content (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Embryos as targets of endocrine disrupting contaminants in wildlife
Authors: Hamlin Heather J. , Guillette Louis J. 
Published: March 2011

AbstractEnvironmental contaminants are now a ubiquitous part of the ecological landscape, and a growing literature describes the ability of many of these chemicals to alter the developmental trajectory of the embryo. Because many environmental pollutants readily bioaccumulate in lipid rich tissues, wildlife can attain considerable body burdens. Embryos are often exposed to these pollutants through maternal transfer, and a growing number of studies report long‐term or permanent developmental consequences. Many biological mechanisms are reportedly affected by environmental contaminants in the developing embryo and fetus, including neurodevelopment, steroidogenesis, gonadal differentiation, and liver function. Embryos are not exposed to one chemical at a time, but are chronically exposed to many chemicals simultaneously. Mixture studies show that for some developmental disorders, mixtures of chemicals cause a more deleterious response than would be predicted from their individual toxicities. Synergistic responses to low dose mixtures make it difficult to estimate developmental outcomes, and as such, traditional toxicity testing often results in an underestimate of exposure risks. In addition, the knowledge that biological systems do not necessarily respond in a dose‐dependent fashion, and that very low doses of a chemical can prove more harmful than higher doses, has created a paradigm shift in studies of environmental contaminant‐induced dysfunction. Although laboratory studies are critical for providing dose‐response relationships and determining specific mechanisms involved in disease etiology, wildlife sentinels more accurately reflect the genetic diversity of real world exposure conditions, and continue to alert scientists and health professionals alike of the consequences of developmental exposures to environmental pollutants. Birth Defects Research (Part C) 93:19–33, 2011. © 2011 Wiley‐Liss, Inc.
Stimulation of human embryonic stem cell‐derived cardiomyocytes on thin‐film microelectrodes
Authors: Viitanen Jouko , Heimala Päivi , Hokkanen Ari , Iljin Kristiina , Kerkelä Erja , Kolari Kai , Kattelus Hannu 
Published: March 2011

AbstractWe describe successful long‐term stimulation of human embryonic stem cell‐derived cardiomyocyte clusters on thin‐film microelectrode structures in vitro. Interdigitated electrode structures were constructed using plain titanium on glass as the electrode material. Titanium rapidly oxidizes in atmospheric conditions to produce an insulating TiOχ layer with high relative permittivity. Capacitive coupling to the incubation medium and to the cells adherent to the electrodes was still efficient, and the dielectric layer prevented electrolysis, allowing a wider window of possible stimulation amplitudes to be used, relative to conducting surfaces. A common hypothesis suggests that to achieve proper differentiation of electroactive cells from the stem cells electrical stimuli are also needed. Spontaneously beating cardiomyocyte clusters were seeded on the glass‐electrode surfaces, and we successfully altered and resynchronized a clearly different beat interval. The new pace was reliably maintained for extended periods of several tens of minutes.
Enhanced productivity of NS0 cells in fed‐batch culture with cholesterol nanoparticle supplementation
Authors: Wu Yun , Ma Ningning , Wyslouzil Barbara E. , Chalmers Jeffrey J. , McCormick Ellen , Casnocha Susan A. 
Published: March 2011

AbstractNS0 cells are an important industrial cell line for the production of therapeutic monoclonal antibodies. Culturing these cells is challenging because they are cholesterol auxotrophs, and providing cholesterol to the cells is hampered by the low solubility of lipids in aqueous medium. Limited loading capacity, precipitation, instability, and toxicity are associated with traditional delivery methods that involve solvents or carrier molecules. In this work, nanoparticle cholesterol mixtures (NCM) were produced by electrohydrodynamic spraying and added directly to a cholesterol auxotroph NS0 cell line. Compared to a cholesterol‐cyclodextrin solution and a commercial proprietary cholesterol solution, SyntheChol™ NS0 supplement, NCM is significantly less cytotoxic. In the fed batch cell culture process, product titer was increased by 32% when the NCM supplement replaced SyntheChol™ NS0 supplement. An even greater product titer improvement, 64%, was achieved when both NCM and SyntheChol™ NS0 supplements were used in the fed‐batch process. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Engineering an Allosteric Binding Site for Aminoglycosides into TEM1‐β‐Lactamase
Authors: Volkov Alexander N. , Barrios Humberto , Mathonet Pascale , Evrard Christine , Ubbink Marcellus , Declercq Jean‐Paul , Soumillion Patrice , Fastrez Jacques 
Published: March 2011

AbstractAllosteric regulation of enzyme activity is a remarkable property of many biological catalysts. Up till now, engineering an allosteric regulation into native, unregulated enzymes has been achieved by the creation of hybrid proteins in which a natural receptor, whose conformation is controlled by ligand binding, is inserted into an enzyme structure. Here, we describe a monomeric enzyme, TEM1‐β‐lactamase, that features an allosteric aminoglycoside binding site created de novo by directed‐evolution methods. β‐Lactamases are highly efficient enzymes involved in the resistance of bacteria against β‐lactam antibiotics, such as penicillin. Aminoglycosides constitute another class of antibiotics that prevent bacterial protein synthesis, and are neither substrates nor ligands of the native β‐lactamases. Here we show that the engineered enzyme is regulated by the binding of kanamycin and other aminoglycosides. Kinetic and structural analyses indicate that the activation mechanism involves expulsion of an inhibitor that binds to an additional, fortuitous site on the engineered protein. These analyses also led to the defining of conditions that allowed an aminoglycoside to be detected at low concentration.
Tungsten(0)‐ and Rhenium(I)‐Catalyzed Tandem Cyclization of Acetylenic Dienol Silyl Ethers Based on Geminal Carbo‐Functionalization of Alkynes
Authors: Kusama Hiroyuki , Karibe Yusuke , Imai Rie , Onizawa Yuji , Yamabe Hokuto , Iwasawa Nobuharu 
Published: March 2011

AbstractTungsten(0)‐ and rhenium(I)‐catalyzed reactions of acetylenic dienol silyl ethers based on the concept of geminal carbo‐functionalization of alkynes are reported. Treatment of 3‐siloxy‐1,3‐diene‐7‐ynes with catalytic amounts of [W(CO)6] or [ReCl(CO)5] under photoirradiation conditions gives synthetically useful bicyclo[3.3.0]octane derivatives in good yields. Extremely high catalytic activity is noted for the rhenium(I) complex. The reaction has been extended to substrates containing a nitrogen atom in their tethers. In this case, two kinds of synthetically useful heterocyclic compounds—the 2‐azabicyclo[3.3.0]octane derivatives 9 and the monocyclic dihydropyrroles 10, with allenyl substituents—are obtained, and selective preparation of either product can be achieved through the use of an appropriate combination of the nitrogen substituent and the type of the rhenium(I) catalyst. The 2‐azabicyclo[3.3.0]octane derivatives 9 are obtained selectively by carrying out treatment of NNs derivatives in the presence of [ReCl(CO)4(PPh3)], whereas the dihydropyrrole derivatives 10 are obtained by treatment of NMbs derivatives with [ReCl(CO)5]/AgSbF6. Finally, we have applied this geminal carbo‐functionalization to one‐carbon‐elongated substrates containing NTs moieties in their tethers. Selective 5‐exo cyclization is achieved in the presence of gold(I) or rhenium(I) catalysts, whereas 6‐endo cyclization is observed on use of [W(CO)6].
IL4I1: an inhibitor of the CD8+ antitumor T‐cell response in vivo
Authors: Lasoudris Fanette , Cousin Céline , Prevost‐Blondel Armelle , Martin‐Garcia Nadine , Abd‐Alsamad Issam , Ortonne Nicolas , Farcet Jean‐Pierre , Castellano Flavia , Molinier‐Frenkel Valérie 
Published: March 2011

AbstractThe L‐phenylalanine oxidase IL4I1 inhibits T‐cell proliferation in vitro through H2O2 production, and is highly expressed in tumor‐associated macrophages. IL4I1 is also detected by immunohistochemistry in neoplastic cells from several B‐cell lymphomas and some non‐lymphoid tumors. To evaluate IL4I1's effect on tumor growth, we developed a mouse melanoma model constitutively coexpressing IL4I1 and the GP33 epitope. After GP33 vaccination, tumors developed more frequently in mice injected with IL4I1‐expressing cells in comparison with mice receiving control cells. Tumor escape was preceded by a rapid diminution of IFN‐γ‐producing cytotoxic antitumor CD8+ T cells. Moreover, tumor incidence was already increased when only 20% of the injected cells expressed IL4I1. The minimal IL4I1 activities leading to tumor escape were close to those detected in human melanoma and mesothelioma. Thus, we demonstrate the immunosuppressive functions of IL4I1 in vivo and suggest that IL4I1 facilitates human tumor growth by inhibiting the CD8+ antitumor T‐cell response.
Catalytic Synthesis of Triaryl Phosphates from White Phosphorus
Authors: Armstrong Kenneth M. , Kilian Petr 
Published: March 2011

AbstractTriaryl phosphates were synthesized from white phosphorus and phenols under aerobic conditions and in the presence of iron catalysts and iodine. Full conversion to phosphates was achieved without the use of chlorine, and the reactions do not produce acid waste. Triphenyl phosphate, tritolyl phosphate and tris(2,4‐di‐tert‐butyl)phenyl phosphate were synthesized by this method with high selectivities. Various iron(III) diketonates were used to catalyze the conversion. Mechanistic studies showed that the reaction proceeds by formation of PI3, then O=PI(OPh)2 before the final formation of the phosphate. The nucleophilic substitution of O=PI(OPh)2 with phenol to form O=P(OPh)3 was found to be the rate‐limiting step.
Separation of nickel catalyst by microfiltration
Authors: Subrahmanyam C. V. , Rao M. Venkateswara , Bhowmick D. N. 
Published: March 2011

AbstractCeramic membranes with pore size of 0.1 and 0.2 µm are used for the separation of nickel catalyst. Effect of trans‐membrane pressure (TMP), linear velocity, temperature and nickel content (solute) on flux and rejection has been investigated. The flux increased with increase in pore size of the membrane. The rejection characteristics were similar for 0.1 and 0.2 µm membranes. The nickel content and iodine value of the membrane‐filtered oil was comparable with that of conventional processes. Permeate flux increased with increase in temperature. Flux increased with increase in linear velocity and a marginal rise was observed above 2.09 m/s. The rejection characteristics were only slightly affected by higher linear velocity. The flux improved after back flushing. The average flux was higher with back flushing as compared to continuous (with out back flushing) filtration process. The results indicated that the secondary layer effect was more pronounced in microfiltration. The flux decreased with increase in solute concentration. The rejection characteristics were not affected by solute concentration. The rejection characteristic of the membranes remained unaltered after membranes were repeatedly cleaned with sodium hydroxide and HCl solutions, however, the flux was decreased marginally.
A field study of mean and turbulent flow characteristics upwind, over and downwind of barchan dunes
Authors: Baddock Matthew C. , Wiggs Giles F. S. , Livingstone Ian 
Published: March 2011

ABSTRACTField‐measured patterns of mean velocity and turbulent airflow are reported for isolated barchan dunes. Turbulence was sampled using a high frequency sonic anemometer, deriving near‐surface Reynolds shear and normal stresses. Measurements upwind of and over a crest‐brink separated barchan indicated that shear stress was sustained despite a velocity reduction at the dune toe. The mapped streamline angles and enhanced turbulent intensities suggest the effects of positive streamline curvature are responsible for this maintenance of shear stress. This field evidence supports an existing model for dune morphodynamics based on wind tunnel turbulence measurements.Downwind, the effect of different dune profiles on flow re‐attachment and recovery was apparent. With transverse incident flow, a re‐attachment length between 2·3 and 5·0h (h is dune brink height) existed for a crest‐brink separated dune and 6·5 to 8·6h for a crest‐brink coincident dune. The lee side shear layer produced elevated turbulent stresses immediately downwind of both dunes, and a decrease in turbulence with distance characterized flow recovery. Recovery of mean velocity for the crest‐brink separated dune occurred over a distance 6·5h shorter than the crest‐brink coincident form.As the application of sonic anemometers in aeolian geomorphology is relatively new, there is debate concerning the suitability of processing their data in relation to dune surface and streamline angle. This paper demonstrates the effect on Reynolds stresses of mathematically correcting data to the local streamline over varying dune slope. Where the streamline angle was closely related to the surface (windward slope), time‐averaged shear stress agreed best with previous wind tunnel findings when data were rotated along streamlines. In the close lee, however, the angle of downwardly projected (separated) flow was not aligned with the flat ground surface. Here, shear stress appeared to be underestimated by streamline correction, and corrected shear stress values were less than half of those uncorrected. Copyright © 2011 John Wiley & Sons, Ltd.
Impact of coal structural heterogeneity on the nonideal sorption of organic contaminants
Authors: Shi Xin , Fu Heyun , Li Yuan , Mao Jingdong , Zheng Shourong , Zhu Dongqiang 
Published: March 2011

Abstract
Carbonaceous geosorbents (black carbon, coal, and humin/kerogen) play a primary role in the nonideal sorption (isotherm nonlinearity, hysteresis, and multiphasic kinetics) of hydrophobic organic chemicals by soils and sediments. The present study investigated the impact of coal structural heterogeneity on sorption/desorption of two model monoaromatic compounds (1,3-dichlorobenzene and 1,3-dinitrobenzene). Due to the higher degree of aromaticity and condensation, anthracite showed stronger sorption affinity and nonlinearity and slower sorption kinetics than lignite. Removal of humic substances by alkali extraction and/or mineral fraction by acidification did not much affect organic carbon-normalized sorption coefficient to the coal, suggesting nearly complete accessibility of adsorption sites on the condensed organic carbon. However, the treatments greatly increased sorption kinetics and meanwhile alleviated hysteresis of 1,3-dinitrobenzene, as compared with the original lignite. These observations were attributed to the enhanced exposure of high-energy adsorption sites on the condensed organic carbon after exfoliating the surface coverage by humic substances and minerals. An empirical biphasic pseudo-second-order model consisting of a fast sorption phase and a slow sorption phase adequately quantified the overall sorption kinetics for the coal sorbents. The results indicated that the condensed organic carbon, in combination with other structural components, controls the nonideal sorption of unburned coal. Environ. Toxicol. Chem. 2011; 30:1310–1319. © 2011 SETAC
The influence of psychological, social and contextual factors on the expression and measurement of awareness in early‐stage dementia: testing a biopsychosocial model
Authors: Clare Linda , Nelis Sharon M. , Martyr Anthony , Roberts Judith , Whitaker Christopher J. , Markova Ivana S. , Roth Ilona , Woods Robert T. , Morris Robin G. 
Published: March 2011

BackgroundInsufficient attention has been paid to the influence of psychological and social factors on discrepancy‐based measures of awareness.ObjectivesThe present study tested a biopsychosocial model of awareness in early‐stage dementia by gathering evidence regarding the relative contributions of neuropsychological, individual psychological and social factors to the level of scoring on measures used to index awareness.MethodAwareness was assessed in relation to memory, activities of daily living and social functioning in 101 individuals with early‐stage dementia participating in the Memory Impairment and Dementia Awareness (MIDAS) Study. People with dementia (PwD) and carers also completed measures of individual psychological and social variables, and PwD completed measures of neuropsychological functioning.ResultsScores on discrepancy‐based indices of awareness and on the self‐ratings and informant ratings contributing to these indices were associated with a range of factors including neuropsychological functioning of PwD, individual traits and dispositions and current affective functioning of PwD, socio‐demographic characteristics of PwD and carers, carer well‐being and carer perceptions of PwD and of quality of relationship with PwD. Patterns of association varied across domains of functioning.ConclusionsThe findings support the relevance of a biopsychosocial approach to understanding the factors that influence unawareness of impairment in dementia. Copyright © 2011 John Wiley & Sons, Ltd.