bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activation‐induced deaminase–deficient MRL/lpr mice secrete high levels of protective antibodies against lupus nephritis
Authors: Jiang Chuancang , Zhao Ming‐Lang , Scearce Richard M. , Diaz Marilyn 
Published: January 2011

AbstractObjectiveWe previously generated MRL/lpr mice deficient in activation‐induced deaminase (AID) that lack isotype switching and immunoglobulin hypermutation. These mice have high levels of unmutated (germline) autoreactive IgM, yet they experienced an increase in survival and an improvement in lupus nephritis that exceeded that of MRL/lpr mice lacking IgG. The purpose of the present study was to test the hypothesis that high levels of germline autoreactive IgM in these mice confer protection against lupus nephritis.MethodsAutoreactive IgM antibodies of various specificities, including antibodies against double‐stranded DNA (dsDNA), from AID‐deficient MRL/lpr mice were given to asymptomatic MRL/lpr mice, and the levels of cytokines, proteinuria, immune complex deposition in the kidneys, and glomerulonephritis were examined. Novel AID‐deficient MRL/lpr mice that lack any antibodies were generated for comparison to AID‐deficient MRL/lpr mice that secrete only IgM.ResultsTreatment with IgM anti‐dsDNA resulted in a dramatic improvement in lupus nephritis. Other autoreactive IgM antibodies, such as antiphospholipid and anti‐Sm, did not alter the pathologic changes. Secretion of proinflammatory cytokines by macrophages and the levels of inflammatory cells and apoptotic debris in the kidneys were lower in mice receiving IgM anti‐dsDNA. Protective IgM derived from AID‐deficient MRL/lpr mice displayed a distinct B cell repertoire, with a bias toward members of the VH7183 family.ConclusionIgM anti‐dsDNA protected MRL/lpr mice from lupus nephritis, likely by stopping the inflammatory cascade leading to kidney damage. A distinct repertoire of VH usage in IgM anti‐dsDNA hybridomas from AID‐deficient mice suggests that there is enrichment of a dedicated B cell population that secretes unmutated protective IgM in these mice.
B cell reconstitution and T helper cell balance after rituximab treatment of active primary Sjögren's syndrome: A double‐blind, placebo‐controlled study
Authors: Abdulahad W. H. , Meijer J. M. , Kroese F. G. M. , Meiners P. M. , Vissink A. , Spijkervet F. K. L. , Kallenberg C. G. M. , Bootsma H. 
Published: January 2011

AbstractObjectiveTo assess the phenotype of reconstituting B cells after B cell depletion, and to assess the effect of reconstitution on the balance of Treg cells and effector T cells in patients with active primary Sjögren's syndrome (SS).MethodsTwenty‐eight patients with primary SS were treated on days 1 and 15 with either rituximab (n = 19) or placebo (n = 9). The frequencies and absolute numbers of circulating B cell subsets, Treg cells, and effector T cells were examined in fresh blood samples by 4‐color flow cytometry at baseline and 5, 12, 24, 36, and 48 weeks after the first infusion. The results in rituximab‐treated patients were compared with those in patients receiving placebo and with those in age‐ and sex‐matched healthy controls (n = 10).ResultsAt baseline, patients with primary SS displayed several abnormalities in B cell homeostasis, including a significant reduction of CD27+ B cells and expansion of CD27– B cells, compared with healthy controls. At week 48 after rituximab treatment, the majority of emerging B cells exhibited a phenotype of transitional B cells. Although recovery of CD27+ memory B cells was delayed after rituximab treatment, a significant increase in Ig class–switched memory B cells within the memory pool was observed. In addition, percentages and absolute numbers of Treg cells and effector T cells, as well as ratios of effector T cells to Treg cells, did not change significantly after rituximab treatment.ConclusionThe characteristics of reconstituted B cells in patients with primary SS following depletion by rituximab treatment showed dominance of transitional B cells during the early recovery phase, which corresponds to bone marrow–derived repopulation. The depletion of B cells did not influence the balance of peripheral Treg cells and effector T cells.
Pharmacodynamic analysis of stress erythropoiesis: change in erythropoietin receptor pool size following double phlebotomies in sheep
Authors: Saleh Mohammad I. , Widness John A. , Veng‐Pedersen Peter 
Published: January 2011

AbstractA feedback receptor regulation model was incorporated into a pharmacodynamic model to describe the stimulation of hemoglobin (Hb) production by endogenous erythropoietin (EPO). The model considers the dynamic changes that take place in the EPO receptor (EPOR) pool under phlebotomy‐induced anemia. Using a125I‐rhEPO tracer the EPO clearance changes are evaluated longitudinally prior to and following phlebotomy‐induced anemia indirectly to evaluate changes in the EPOR pool size, which has been shown to be linearly related to the clearance. The proposed model simultaneously captures the general behavior of temporal changes in Hb relative to EPO plasma clearance in five lambs (r= 0.95), while accounting for the confounding variables of phlebotomy and changes in the blood volume in the growing animals. The results indicate that under anemia the EPOR pool size is up‐regulated by a factor of nearly two over baseline and that the lowest and highest EPOR pool sizes differ by a factor of approximately four. The kinetic model developed and the data‐driven mechanism proposed serves as a starting point for developing an optimal EPO dosing algorithm for the treatment of neonatal anemia. Copyright © 2011 John Wiley & Sons, Ltd.
Everyday antiracism in interpersonal contexts: Constraining and facilitating factors for ‘speaking up’ against racism
Authors: Mitchell Margaret , Every Danielle , Ranzijn Rob 
Published: January 2011

AbstractEveryday conversations among non‐Indigenous Australians are a significant site in which racism towards Indigenous Australians is reproduced and maintained. This study explores the possibilities of everyday antiracism by asking how people negotiate racist discourses in interpersonal contexts. Twelve first year psychology students (10 female, 2 male, aged 18–50) who had completed a compulsory Indigenous studies course were recruited as participants. Semi‐structured interviews were thematically analysed for the constraints and facilitators for responding to racism in everyday contexts. As constraints against speaking up, participants offered ‘social expectations to fit in’, ‘fear of provoking aggression and conflict’, assessments of ‘the type of relationship’, whether they ‘could make a difference’ and the ‘type of racism’. As a facilitator for speaking up, participants reported they were confident in challenging erroneous statements when they felt well informed and authoritative about the facts. The research suggests that everyday antiracism requires a preparedness to deal with possible discomfort and ‘bad feeling’ which participants reported avoiding. The paper concludes with suggestions for stimulating critical thinking and intergroup dialogue in relation to everyday antiracism. Copyright © 2011 John Wiley & Sons, Ltd.
A G‐Quadruplex Aptamer Inhibits the Phosphatase Activity of Oncogenic Protein Shp2 in vitro
Authors: Hu Jia , Wu Jie , Li Cong , Zhu Ling , Zhang Wei Yun , Kong Guiping , Lu Zhongxian , Yang Chaoyong James 
Published: January 2011

AbstractShp2 is a member of the protein tyrosine phosphatase (PTP) family, which regulates a variety of cellular processes including cell growth, differentiation, mitotic cycle, and oncogenic transformation. Using a recombinant Shp2‐GST protein as the target and GST as a counter target, we have identified two classes of single‐stranded DNA aptamers that selectively bind to Shp2 with a Kd in the nanomolar range. Structural studies of the most abundant sequence in the enriched library, HJ24, revealed a parallel G‐quadruplex as the core binding domain. Furthermore, this aptamer was found to be an effective inhibitor of Shp2 phosphatase, an effect which was readily reversed by using the cDNA of HJ24. In view of these characteristics, this aptamer has the potential to be used for further development of Shp2 assays and therapeutics for the treatment of Shp2‐dependent cancers and other diseases.
Bacterial Inclusion Bodies of Alzheimer's Disease β‐Amyloid Peptides Can Be Employed To Study Native‐Like Aggregation Intermediate States
Authors: Dasari Muralidhar , Espargaro Alba , Sabate Raimon , Lopez del Amo Juan Miguel , Fink Uwe , Grelle Gerlinde , Bieschke Jan , Ventura Salvador , Reif Bernd 
Published: January 2011

AbstractThe structures of oligomeric intermediate states in the aggregation process of Alzheimer's disease β‐amyloid peptides have been the subject of debate for many years. Bacterial inclusion bodies contain large amounts of small heat shock proteins (sHSPs), which are highly homologous to those found in the plaques of the brains of Alzheimer's disease patients. sHSPs break down amyloid fibril structure in vitro and induce oligomeric assemblies. Prokaryotic protein overexpression thus mimics the conditions encountered in the cell under stress and allows the structures of Aβ aggregation intermediate states to be investigated under native‐like conditions, which is not otherwise technically possible. We show that IB40/IB42 fulfil all the requirements to be classified as amyloids: they seed fibril growth, are Congo red positive and show characteristic β‐sheet‐rich CD spectra. However, IB40 and IB42 are much less stable than fibrils formed in vitro and contain significant amounts of non‐β‐sheet regions, as seen from FTIR studies. Quantitative analyses of solution‐state NMR H/D exchange rates show that the hydrophobic cores involving residues V18‐F19‐F20 adopt β‐sheet conformations, whereas the C termini adopt α‐helical coiled‐coil structures. In the past, an α‐helical intermediate‐state structure has been postulated, but could not be verified experimentally. In agreement with the current literature, in which Aβ oligomers are described as the most toxic state of the peptides, we find that IB42 contains SDS‐resistant oligomers that are more neurotoxic than Aβ42 fibrils. E. coli inclusion bodies formed by the Alzheimer's disease β‐amyloid peptides Aβ40 and Aβ42 thus behave structurally like amyloid aggregation intermediate states and open the possibility of studying amyloids in a native‐like, cellular environment.
Nickel‐Loaded Zirconia Catalysts with Large Specific Surface Area for High‐Temperature Catalytic Applications
Authors: Peters Andreas , Nouroozi Fatemeh , Richter Dennis , Lutecki Michal , Gläser Roger 
Published: January 2011

AbstractHighly porous and thermally stable zirconia is prepared by a template‐assisted route using dodecylamine (DDA) and a post‐treatment in ammonia solution at different pH. The resulting materials are calcined at 700 °C and characterized by elemental analysis, optical emission spectrometry with inductively coupled plasma (ICP‐OES), N2 sorption, XRD, high‐resolution TEM, and, after loading with 5 wt % nickel, also by temperature‐programmed reduction and temperature‐programmed desorption of ammonia (TPDA). With increasing pH of the post‐treatment, the specific surface area increases up to 156 m2 g−1 and the diameter of the predominantly tetragonal crystallites decreases from 10.3 to 5.7 nm, independently of the presence of Ni. The high specific surface area is shown to be a result of the incorporation of silicon (<2.5 wt %) dissolved from the glass vessels during the post‐treatment. Despite the presence of acid sites, the Ni‐loaded zirconia are active and selective catalysts in the dry reforming of CH4 with CO2 at 750 °C. With conversions up to 79 % and H2 selectivities up to 87 %, the catalysts supported on zirconia prepared by the DDA route and ammonia post‐treatment are significantly more active than those with zirconia supports prepared by conventional precipitation or in the absence of silicon or DDA.
Au Nanowire‐on‐Film SERRS Sensor for Ultrasensitive Hg2+ Detection
Authors: Kang Taejoon , Yoo Seung Min , Yoon Ilsun , Lee Sangyeop , Choo Jaebum , Lee Sang Yup , Kim Bongsoo 
Published: January 2011

AbstractWe report an ultrasensitive and selective single nanowire‐on‐film (SNOF) surface‐enhanced resonance Raman scattering (SERRS) sensor for Hg2+ detection based on structure‐switching double stranded DNAs (dsDNAs). Binding of Hg2+ induces conformational changes of the dsDNAs and let a Raman reporter get close to the SNOF structure, thereby turning on SERRS signal. The well‐defined SNOF structure provides a detection limit of 100 pM with improved accuracy in Hg2+ detection. This sensor is stable over a considerable amount of time and reusable after simple treatment. Since this SNOF sensor is composed of a single Au NW on a film, development of a multiplex sensor would be possible by employing NWs modified by multiple kinds of aptamers.
Pure Trinuclear 4 f Single‐Molecule Magnets: Synthesis, Structures, Magnetism and Ab Initio Investigation
Authors: Guo Fu‐Sheng , Liu Jun‐Liang , Leng Ji‐Dong , Meng Zhao‐Sha , Lin Zhuo‐Jia , Tong Ming‐Liang , Gao Song , Ungur Liviu , Chibotaru Liviu F. 
Published: January 2011

AbstractA family of linear Dy3 and Tb3 clusters have been facilely synthesized from the reactions of DyCl3, the polydentate 3‐methyloxysalicylaldoxime (MeOsaloxH2) ligand with auxiliary monoanionic ligands, such as trichloroacetate, NO3−, OH−, and Cl−. Complexes 1–5 contain a nearly linear Ln3 core, with similar Ln⋅⋅⋅Ln distances (3.6901(4)–3.7304(3) Å for the Dy3 species, and 3.7273(3)–3.7485(5) Å for the Tb3 species) and Ln⋅⋅⋅Ln⋅⋅⋅Ln angles of 157.036(8)–159.026(15)° for the Dy3 species and 157.156(8)–160.926(15)° for the Tb3 species. All three Ln centers are bridged by the two doubly‐deprotonated [MeOsalox]2− ligands and two of the four [MeOsaloxH]− ligands through the N,O‐η2‐oximato groups and the phenoxo oxygen atoms (Dy‐O‐Dy angles=102.28(16)–106.85(13)°; Tb‐O‐Tb angles=102.00(11)–106.62(11)°). The remaining two [MeOsaloxH]− ligands each chelate an outer LnIII center through their phenoxo oxygen and oxime nitrogen atoms. Magnetic studies reveal that both Dy3 and Tb3 clusters exhibit significant ferromagnetic interactions and that the Dy3 species behave as single‐molecule magnets, expanding upon the recent reports of the pure 4f type SMMs.
Two Successive Reactions on a DNA Template: A Strategy for Improving Background Fluorescence and Specificity in Nucleic Acid Detection
Authors: Franzini Raphael M. , Kool Eric T. 
Published: January 2011

AbstractWe report a new strategy for template‐mediated fluorogenic chemistry that results in enhanced performance for the fluorescence detection of nucleic acids. In this approach, two successive templated reactions are required to induce a fluorescence signal, rather than only one. These novel fluorescein‐labeled oligonucleotide probes, termed 2‐STAR (STAR=Staudinger‐triggered α‐azidoether release) probes, contain two quencher groups tethered by separate reductively cleavable linkers. When a 2‐STAR quenched probe successively binds adjacent to two mono‐triphenylphosphine‐(TPP)‐DNAs or one dual‐TPP‐DNA, the two quenchers are released, resulting in a fluorescence signal. Because of the requirement for two consecutive reactions, 2‐STAR probes display an unprecedented level of sequence specificity for template‐mediated probe designs. At the same time, background emission generated by off‐template reactions or incomplete quenching is among the lowest of any fluorogenic reactive probes for the detection of DNA or RNA.
Factors That Control Zeolite L Crystal Size
Authors: Itani Lama , Bozhilov Krassimir N. , Clet Guillaume , Delmotte Luc , Valtchev Valentin 
Published: January 2011

AbstractTime‐series hydrothermal syntheses from two organic‐cation‐free gels with different compositions were employed to study the factors that control the final size of zeolite L crystals. The first gel had a starting K/Al ratio of 10, whereas in the second one it was three times lower. The relatively simple chemical composition of the starting gels and the combination of complementary characterization methods allowed us to track down the different stages of transformation of the initial amorphous gels into zeolite crystals and the factors that control the nucleation and growth processes. The role of the starting mixture components in the formation of the primary amorphous particles was explored. It was found that the profoundly different reaction kinetics in the two systems are caused by the difference in diffusion rates, which in turn are controlled by the extent of the polymerization reactions at room temperature during mixing of the starting components prior to hydrothermal treatment. As a consequence, nucleation is fast and ubiquitous in the first system with higher water content and K/Al ratio, whereas it is slow and sporadic in the second system with lower water content and K/Al ratio. Ultimately, these differences in the kinetics lead to the formation of two distinctly different patterns of crystal‐size distribution, with a large number of small nanocrystals in the first sample and fewer large crystals in the second sample. The new findings put zeolite crystal growth on a rational basis that would enable the control of zeolite crystal size in similar organic‐template‐free systems.
Regioselectivity of the Claisen Rearrangement in meta‐Allyloxy Aryl Ketones: An Experimental and Computational Study, and Application in the Synthesis of (R)‐(−)‐Pestalotheol D
Authors: Lucas Catherine L. , Lygo Barry , Blake Alexander J. , Lewis William , Moody Christopher J. 
Published: January 2011

AbstractA study of the regioselectivity of the Claisen rearrangement of meta‐allyloxy aryl ketones showed that the electron‐withdrawing carbonyl group has a major influence and strongly directs rearrangement to the more hindered ortho position. However, when the ketone is part of a ring structure, its electronic effect can be negated by conversion into its triisopropylsilyl enol ether, which dramatically reverses the regiochemistry of the Claisen rearrangement. DFT calculations suggest that the effect is electronic although there is also a steric effect of the bulky silyl group. This strategy for influencing the regiochemical outcome of the Claisen rearrangement was then employed in a short synthesis of the furo[2,3‐g]chromene, (−)‐pestalotheol D, that confirms the absolute stereochemistry of the natural product.
Geometry Relations with Bed Load Formulae for Alluvial Boundaries
Authors: Yilmaz Levent 
Published: January 2011

AbstractEmploying bed load formulae hydraulic geometry relations were derived for stream width, sediment transport velocity, and bed slope. The relations were examined in terms of friction factor, bed load discharge, bed load diameter, and water discharge. Two fundamental approaches to the prediction of hydraulic geometry have been developed. The first and most widely adopted approach is based on empirical equations whereas the second is based on solution of the governing equations of flow. The applied bed load formulae belong to different authors. Here, the comparison with the other derived relations is presented.
Evaluation of a Novel Control Method on Biofilm Parameters in an Aerated Submerged Fixed‐bed Biofilm Reactor
Authors: Trojanowicz Karol , Wojcik Wlodzimierz , Styka Wieslawa , Baczynski Tomasz 
Published: January 2011

AbstractOne of the critical technological parameter in operation of aerated submerged fixed‐bed biofilm reactor (ASFBBR) is the control over process of biofilm detachment. Both, an excessive growth of biomass with its accumulation in the bioreactor and an exceeded biofilm detachment rate, cause serious operational and technological problems. The studies presented in this paper demonstrate that in an ASFBBR reactor with a PVC bed carrier media, an effective way to maintain a proper shear stress acting on the biofilm and causing its detachment could be an internal recirculation of wastewater instead of backwashing with wastewater or air flushing. In case of polishing of oil‐refinery wastewater with average COD loading rate equal to 9 g COD/(m2 day), the minimum value of the hydraulic loading rate in such reactor is 1.9 m3/(m2 h), at which there was no excessive growth of biofilms. Despite a significant decrease of the biofilms thickness and amount of biomass in the reactor, there was no significant decline in the efficiency of pollutant removal from oil‐refinery wastewater, which made it possible to obtain the quality of effluent at the outlet of the bioreactor significantly below the water permits and standards.
Surfactant Enhance DLLME/FO‐LADS: Assay of Malachite Green Level in Aquatic Environment of Trout Fish
Authors: Bidari Araz , Ganjali Mohammad Reza , Norouzi Parviz 
Published: January 2011

AbstractMalachite green (MG), a traditional agent used in aquaculture although is not approved; its low cost and high efficacy make illicit use likely. We developed a small‐scale, simple, and sensitive dispersive liquid–liquid microextraction procedure for the assay of trace amounts of MG in aquatic environment of Trout fish. Fiber optic‐linear array detection spectrophotometry with charge‐coupled device detector benefiting from a microcell was used for this purpose. The method is based on enhancement effect of an anionic surfactant on the extraction of MG in to very fine multidroplets of microextraction solvent which made assisted by disperser solvent. Under the optimum conditions, the enrichment factor 77.5 was obtained from a 5‐mL water sample. The calibration graph was linear up to 5 × 10−7 mol L−1 with detection limit of 1 × 10−8 mol L−1. The relative standard deviation for seven replicate measurements of 4 × 10−7 and 5 × 10−8 mol L−1 of MG were 3.3 and 4.5%, respectively.
Dividing the spoils of growth and the cell cycle: The fission yeast as a model for the study of cytokinesis
Authors: Goyal Anupama , Takaine Masak , Simanis Viesturs , Nakano Kentaro 
Published: January 2011

AbstractCytokinesis is the final stage of the cell cycle, and ensures completion of both genome segregation and organelle distribution to the daughter cells. Cytokinesis requires the cell to solve a spatial problem (to divide in the correct place, orthogonally to the plane of chromosome segregation) and a temporal problem (to coordinate cytokinesis with mitosis). Defects in the spatiotemporal control of cytokinesis may cause cell death, or increase the risk of tumor formation [Fujiwara et al., 2005 (Fujiwara T, Bandi M, Nitta M, Ivanova EV, Bronson RT, Pellman D. 2005. Cytokinesis failure generating tetraploids promotes tumorigenesis in p53‐null cells. Nature 437:1043–1047); reviewed by Ganem et al., 2007 (Ganem NJ, Storchova Z, Pellman D. 2007. Tetraploidy, aneuploidy and cancer. Curr Opin Genet Dev 17:157–162.)]. Asymmetric cytokinesis, which permits the generation of two daughter cells that differ in their shape, size and properties, is important both during development, and for cellular homeostasis in multicellular organisms [reviewed by Li, 2007 (Li R. 2007. Cytokinesis in development and disease: variations on a common theme. Cell Mol Life Sci 64:3044–3058)]. The principal focus of this review will be the mechanisms of cytokinesis in the mitotic cycle of the yeast Schizosaccharomyces pombe. This simple model has contributed significantly to our understanding of how the cell cycle is regulated, and serves as an excellent model for studying aspects of cytokinesis. Here we will discuss the state of our knowledge of how the contractile ring is assembled and disassembled, how it contracts, and what we know of the regulatory mechanisms that control these events and assure their coordination with chromosome segregation. © 2011 Wiley‐Liss, Inc.